Nodal Analysis - Kirchoffs Current Law

Question:
Hello, I am stumbling across an issue here. So in Nodal Analysis, we identify our reference point and label the voltage nodes. Then we use KCL to find out equations and solve. My book is providing an example in the picture I've provided. In the highlighted red, why did they decide to multiply it by a negative? -3A is coming out of Node 2. When do we need to multiply it by a negative? And also, how do I make my direction currents consistence so I can get the correct answer? I know we have to choose our current direction but I keep getting the signs wrong. Much help is appreciated.
Answer: Preface note: I originally used \$3\:\text{A}\$ as the current source. But I mis-read the problem, as stated. They specify, on the schematic, that the out-flowing current source value is \$-3\:\text{A}\$. The original error is mine. It is fixed, now, below.
The node is (by super-position):
$$\overbrace{\frac{V_2}{3\:\Omega}+\frac{V_2}{1\:\Omega}+\frac{V_2}{7\:\Omega}+\left(-3\:\text{A}\right)}^{\text{Outward-flowing currents}}=\overbrace{\frac{V_1}{3\:\Omega}+\frac{0\:\text{V}}{1\:\Omega}+\frac{V_3}{7\:\Omega}}^{\text{Inward-flowing currents}}$$
Moving everything from the right side over to the left side gives:
$$\frac{V_2-V_1}{3\:\Omega}+\frac{V_2}{1\:\Omega}+\frac{V_2-V_3}{7\:\Omega}+\left(-3\:\text{A}\right)=0\:\text{A}$$
Moving the constant to the right and you have:
$$\frac{V_2-V_1}{3\:\Omega}+\frac{V_2}{1\:\Omega}+\frac{V_2-V_3}{7\:\Omega}=3\:\text{A}$$
Does that help at all?
Note
Voltage spills away from a node via available paths and voltage spills into a node from nearby nodes via the same available paths. The only caveat is that a current source can only flow into, or flow out of, a node. But not both directions. (Current sources only work one way. So it will either appear on the outward-flowing side or on the inward-flowing side -- but not both sides.)
Comment: thanks for the explanation
Comment: I like your explanation on which currents flow inwards and outwards which helps me understand. In the final simplified equation I have gotten that exactly but I'm not sure why the author converts that -3A into a positive.
Comment: @GreenLeaf21 That's ***my*** mistake. I misread the problem's schematic. I'll fix my answer. Thanks for catching that!!
Comment: @GreenLeaf21 If you find the answer sufficient, feel free to select it. This saves the time of others who may misunderstand and imagine you want another answer or two to help out. Doing so respects the time of others. On the other hand, if you really do want to see some different answers to this question, then do NOT select my answer.

Nodal Analysis - Kirchoffs Current Law


Possible to retrieve PDFs deleted from the media library or retain their URL for new version?

Question: I have deleted some PDFs from the Sitecore media library by replacing them with new PDFs which were already added to the library. As a result, the media URL is now changed. The owner now says they forgot to mention that they want to retain the old URL. Is it possible to retrieve the old files and thus their URLs, or force the old URLs on the new files?
Answer: As mentioned here already, the Recycle Bin is keeping deleted files.
If you want to change the pdf that is attached to the media item, you can detach it and attach a new one - this will change the pdf but the item (and the url) will stay the same.
Info about the attach/detach can be found here: https://www.techguilds.com/Blog/2018/06/managing-the-sitecore-media-library

However, be careful!
The pdf is probably cached on several places. You wouldn't be the first one to ask (here or on other community channels) why people still see the old pdf although in Sitecore there is a new one...
In my humble opinion, it is actually a bad idea to keep the url. If it is a new document (or a new version of the document), you should give it it's own url.
Note that Sitecore also supports versioned media items. You can choose this when uploading the asset. With this media type, you can actually create new versions (just like with most items in Sitecore) of the media asset. There is also a setting (Media.AlwaysAppendRevision) you can use to generate different urls per revision.
Answer: Sitecore move deleted files in Recycle Bin and keep it there for some time. I think you can look into Recycle and restore it from there.
See this link to know how to restore or remove a deleted item


Can VirtualBox affect SSE availability?

Question: I'm doing some development in Linux running in VirtualBox. The computer is an Core i5 running Windows 7 (32 bit). According to the entry on Wikipedia, the CPU should support SSE4.2, but only SSE3 works in the VM. If I compile with the -msse4 flag in gcc, the resulting binary would crash with an illegal instruction error.
Answer: This is a known issue and already in their bugtracker:
[feature request] Enable the guest OS to make use of SSE4.1, 4.2 and POPCNT instruction sets
https://www.virtualbox.org/ticket/8651
Answer: VirtualBox or KVM or any other such virtualisation technology exposes some features of the host CPU to the guest.
Why not exporting all features of the host CPU? Imagine you want to migrate your virtual machine from one host to the other, without interruption (or by saving the state). But the second host does not have SSE 4. If your VM would have exposed SSE 4 on host 1 and you would have successfully compiled and execute a program using this instruction set, when migrated to host 2 it will break.
That is why - IMHO - it is wise not to expose every supported instructions set of the host CPU by default and I am not surprised that this is the case with VirtualBox. It should however (and I hope that would be the implemented solution for the ticket) allow user to override the default choice of exposed features. And AFAIK this option does not exist yet. So you will have to be patient.
Note that KVM allows you to set the instructions sets you want to expose to the guest(s) per guest(s).
Comment: Do you have any references for not supporting SSE4 being "to allow you to migrate" and whatnot, versus "we just didn't get around to it yet"?
Comment: Nope I don't. I should probably reformulate my sentence, instead of reading "That is why VirtualBox does not necessarily exposed by default (...)" you should have read "That is why - IMHO - it is wise not to expose every supported instructions set by default and I am not surprised that this is the case with VirtualBox". I hope I am answering your concern.

Can VirtualBox affect SSE availability?


Why did Musharraf quarrel with the Supreme Court?

Question: In reading about Pakistani politics I got the impression that the judiciary is closely associated with the military. However, I remember that Musharraf's fall from power began by his confronting the Supreme Court and trying to fire its head. How do these two points square?
Answer: I think this was part of a power play between then President Pervez Musharraf and chief justice Iftikhar Muhammad Chaudhry in 2007 over Musharraf's attempt to get an extraordinary prolonged mandate as his predecessors had also done, but as Chaudhry would not support.
Here's an excerpt from the Aug 16th 2007 edition of The Economist:

In 2002 General Musharraf amended this clause to grant himself a
  one-off dispensation [from the constitutional rule whereby the president may not hold a second office]. He would like to do so again. But constitutional
  change requires the support of two-thirds of parliament, which he does
  not have. Alternatively, General Musharraf could try to get re-elected
  as a civilian. He would then quit the army, either before his tenure
  expires on November 15th (though he says December 31st), or else he
  would hope to be re-elected by the next parliament. Either way, he
  will be at the judges' mercy. The constitution says the president must
  have held no other public office for two years.

As to the root causes why the opinions were not fully aligned between the Pakistani judiciary and military in 2007, I think these were mainly attributed  to Chaudhry as a personal actor, who had considerable popular support as well as support in the resulting lawyers' movement. I've also heard complaints from inside Pakistan that Western media tend to simplify and portray Chaudhry as a blameless hero: but as always, there must be interesting shades of gray, which I'd also be curious to learn about.
Comment: It's pervez, not perez
Comment: That "gray" link more or less blew my mind. And I do like complicated court intrigues (pun unintended).
Answer: There were plenty of conflicts between the US-backed military dictator and the Chief Justice of Pakistan. Chief among them were following:

The privatization of state owned Pakistan Steel Mills by Musharraf's puppet Prime Minister Shaukat Aziz and the corruption that surrounded the whole thing.
The Missing Persons Case - The disappearences of dissenters and Human rights activists at hands of Government agencies. CJP agreed to hear to these cases against intelligence organizations and took personal notice of the Human rights violations by the state agencies. Every day passing made him even more resolved in solving the case and forcing the agencies to produce the abducted people in front of the court.
Increasing interference by the courts in irregular conduct of the administration to put an end to the rampant corruption and nepotism especially by the military Junta and their political stooges.
The final straw was when CJP approved some petitions for hearing which challenged Musharraf's occupation of the posts of President and Army chief simultaneously and also a legal reference challenging that the current Parliament had no constitutional jurisdiction to re-elect Musharraf for another tenure.

This alarmed the Military Junta as it was getting clearer every day that the Judiciary may undo everything they had done if it was allowed to go ahead with their new found independence and courage, something which was never seen in the judiciary in the past, when they always put a legal stamp on all illegal acts of Army.
Musharraf chose to strike first, he asked Iftikhar Chaudary to visit him in presence of Top military brass including the heads of the much feared intelligence agencies. To his greatest surprise, Iftikhar refused to "Go away quietly" by resigning as demanded by the Junta. Defiance wasn't a dish that the dictator tasted often.
The result was something not seen in Pakistan for decades. People lined highways just to get a glimpse of the man.
It wasn't just what he did, it was what he had become. He had become a symbol of resistance against the military dictatorship and against the human rights abuses committed under the pretext of Global war on terror, which was very unpopular in Pakistan back then and most Pakistanis did not believe it was their war, rather a foreign war imposed on them by American establishment. Military Junta of course milked it a lot and politcal dissenters were booked as terror suspects every where.
In any case, the following were the root causes of the quarrel Musharraf had with judiciary:

Halting of shady deals on national assets made by the Political stooges of the Junta
Halting of the crackdown on political dissenters operated by the military intelligence agencies, by investigating the missing persons cases put forth by the families of the said people.
Creating legal obstructions in path of administration which greatly annoyed the dictator as he was used to get what he wanted, the way he wanted.
Threatening to strip Musharraf off his military uniform by hearing legal petitions against it. Musharraf knew that his power came from that uniform. If that went away, so would he. Eventually that's what happened.
Threatening Musharraf's ambitions of re-electing himself for another term in the office as President.


Editing SharePoint 2013 Page Layout

Question: we have a custom page layout called HomePage, it has few webpart zone and i need to edit that page and add new web part zone, where should i find the page so i can edited.
Regards
Answer: Publishing page layouts are stored in [Your Site URL]/_catalogs/masterpage/
The process of adding another web part zone to an existing custom page layout involves a number of steps. Generally speaking:

Find the custom page layout HTML file in the masterpage gallery and download it to your machine
Open Design Manager and use the Snippet Gallery to generate the code for your new web part zone (alernatively, find an existing web part zone in your HTML page layout, clone it, and give it a unique ID)
Insert that code into the HTML layout where you want it to appear in the body section
Reupload your HTML page layout source to the masterpage gallery
Publish a major version of that HTML file

EDIT: Here is the alternative way, in more detail...
Now that you've located the web part zone code block, copy the entire thing and paste it into a new area of your page layout.

Update the line that says:

To include a unique ID (can be anything) and title, and you should be good to go.
Comment: Thanks Jake, when i open the page-layout with notepad i can see the ID as like location. Center, Left or right. ID="CenterRightColumn" or ID="CentreColumn", how i can use this ones to create a new one?
Comment: @Harris I will update the answer above
Comment: Hey Jake, appreciated your help

Editing SharePoint 2013 Page Layout


Have WP Theme update from Git Repository

Question: I have a client's theme currently hosted on github. Instead of doing a git deploy or using a service like Beanstalk's deployments. I will be pushing the same theme across many sites (79 to be exact) and want them to be able to update themselves just like a WP repo hosted theme. A good example is how the Genesis framework has it's updates work. I've seen things where you have another plugin installed to do this, but i'm looking for a more minimalist solution (if there is anyway to keep this functionality within the theme itself)?
Answer: There're a couple of libraries out there. One of the more well known is from Joey Kudish and hosted on GitHub itself.
Basically it does the following:

utilizes the GitHub API
Adds a callback to the 'pre_set_site_transient_update_plugins' filter
Adds another callback to the 'plugins_api' filter
finally utilizes the WP HTTP API and does a wp_remote_get() to the GitHub repo.

Oh, yes - close to have forgotten this - it adds a transient to avoid checking the remote repo on every request.
Comment: This looks promising! It is meant for plugins but i'm sure it'll work with themes as well? Do you know of any tool developed for private git repos (not hosted on github)? @kaiser
Comment: @ZachRussell [The HTTP API](http://codex.wordpress.org/HTTP_API)
Answer: You need 2 basic things to accomplish this

Hook into pre_set_site_transient_update_themes
Use the HTTP API to query whatever url has your update

The basic premise is your theme's version is stored in a transient that checks a remote URL every x hours and compares the $version.
Notes:
The URL can be anything, the HTTP API supports authentication (private repo) or anything you want to send via the header.
The check can be any variable comparison, though typically you use a version.
The file can be anything that can be parsed (.xml, .txt) but typically you use the style.css
Instead of me adding code to this check this out: https://github.com/jeremyclark13/automatic-theme-plugin-update , specifically the theme part.


How to remove thermocouple from this manifold door?

Question: It has a black object that seems to be secured down by a U shaped clasp. I cannot see how the clasp can be removed. Everything is tight and doesn't appear that a tool can fit anywhere to loosen it up.
Front

Back
Answer: I was able to get it off by using a hammer and a screwdriver. I hammered a flathead screwdriver onto the end of the clasp-list piece. The clasp is intended to be inserted underneath the black holders and thus can be removed by pulling/pushing it out the opposite direction.
Here is an image of where the screwdriver should be placed to hit off the U-shaped clasp. This is looking at the same place on the second image of the original question but turned upside down.


Why the difference in כאשר צוה ה׳ between Vayakhel and Pekudei?

Question: Why does the Torah consistently say כאשר צוה ה׳ את משה or some equivalent after describing the making of each step of the priestly garments (Exodus 39:1, 5, 7, 21, 26, 29 and 31) but not in the context of the construction of the Miskan itself or its vessels, other than in a very general way (Exodus 36:1 and 38:22)?
Comment: The Torah does use that language regarding the setting up of the Mishkan, though (40:16 and so on)
Comment: Perhaps an additional point can be made - Chazal tell us that Betzalel contravenes Moshe in re-ordering the construction by placing the mishkan before the kelim, while Moshe puts the aron first. Moshe agrees with this process but that therefore means the individual components were technically not "כאשר צוה ה׳ את משה" even though the completed project was. The bigdei kehunah were not changed, so they merit individual commendations of כאשר צוה ה׳ את משה.
Comment: Matt, it also uses that language regarding the "setting up" of the priestly garments (Vayikra 8).
Comment: Three theories: since the Kohanim weren't ready to don the clothes yet, they were "done" for now, unlike the building pieces which could still be assembled; making the priestly garments was more directly assigned to Moshe (perhaps? cf. Ex 28:1-3, 40:1-2) so it gets a KaAsher... *Et Moshe*; priestly garments don't need the structure to function (Makrivin AAP ShEin Bayit) so they were "done" after being made, unlike the structural stuff which needed assembly.
Comment: @DoubleAA I also thought that it had something to do with the garments being complete, while the building still needed construction, but it would be nice if someone could dig up someone else who noticed this. Your second theory... begs another question I think
Answer: Rav Hirsch, in his commentary on Pekudei 39:1 states that the individual garments were commanded separately and were considered complete as soon as they were finished and ready to be worn. The mishkan and its utensils, such as the curtains, etc, could only be considered done after the entire mishkan was assembled.

כאשר צוה ה וגו, it says this when recounting the finishing of the making
  of the garments, but not at the finishing of the various
  components of the משקן. This is only said later when the parts were
  assembled and the Mishkan erected in Ch. XL,19 and 21 et seq. Each
  separate garment was considered finished as soon as it was made. But
  the curtains forming the Tent, the furniture of the Abode etc., could
  only be considered completed when assembled and the Mishkon erected.


I can't use the sd card to download apps

Question: I just got a new phone but when I try to download something it says insufficient space but my sd card has plenty. How do I fix this?
Comment: possible duplicate of [Installing to SDCard by default](http://android.stackexchange.com/questions/43517/installing-to-sdcard-by-default)
Comment: Welcome to the Android Enthusiasts! Please start checking our [insufficient-memory tag-wiki](http://android.stackexchange.com/tags/insufficient-memory/info), which contains some first aid and links to more. Then come back here and let us know how you solved your issue – or tell us what you've tried and where you're stuck.
Comment: That's because your internal memory is full ,allmost. To place app's on SD card you will need apps2sd or link2sd app and phone has to be rooted, also if you have android version 6.0+ you can use feature called adoptable storage so sd card will behave like internal, noo root required but you wouldn't be able to use sd with other phone only if you format it first
Comment: Community bump prevention: this question was closed because the question seems to have been abandoned (OP hasn't visited the site after posting the question, and no answers have score above 0). If anyone can evaluate the existing answers, feel free to vote accordingly and reopen the question (or mod-flag the question requesting for reopening). For anyone else having the same issue, please post a new question and refer to this question as additional context.
Answer: Your SD card can be as big as possible, but Android won't use it. It's not safe for Android to assume your external SD card is always accessible.
Depending on your Android version, your internal storage is shared with your device storage i.e: Applications will not use less storage even if you move them to your SD card.
Answer: You can try the following;

Clear cache or app data.
Uninstall unused app.
Root your device and use link2sd
If your device used MTK processor, try to repartition your internal storage.
Answer: When you find some app on google-play-store and install it, the apk is downloaded to /data/local, i.e. to your internal-storage. You can't change that. Its after this your settings come into picture, your if have set to install it on sdcard it installs to sdcard.
Answer: I did this steps in my Zenfone 5, so I'm pretty sure it'll work. (WARNING : You will void your warranty!)

Root your device. Then I suggest to take a full backup with Titanium Backup.
Repartition your SD card, add 1 ext3 or ext4 partition. You can use TWRP or CWM. (WARNING : It will destroy your SDcard contents! Make a backup first!)
Install Link2SD from Play Store. Select your second partition type, based on what you choose at step 2.
Open settings, look for auto link, enable. (Can't remember the exact name ...)
If you want, you can link already installed apps to your sdcard.

After this, when you installed new application, it will be symlinked to your sdcard's second partition.
Enjoy extra space.
Or better, remove all bloatware with titanium backup. Or use unbloated custom rom.
Your choice. Your warranty has been voided anyway.
Answer: If you have a newer version of android, you can format the SD card to act as internal storage. This essentially acts as additional internal storage and can be extended to whatever your phone is capable of supporting. This should solve your storage issue.
If you have a phone with an android version not compatible with this, you may be able to move some apps that are taking a lot of space, however they will open a lot slower once they're on your external memory.
Answer: This occurs due to lack of space in your device. If you transfer data in your phone (Apps, Images, Music files, etc.) into the SD card space will be free on your device and then you can install more apps.
In the following way you can transfer applications into your SD card.

Settings → Apps → On SD Card → Select the app → Move to SD Card

In this way you can transfer the installed apps in your phone to the SD card. Then you'll be able to install apps. Do the same thing for newly installed apps too to make sure you have enough space in your phone at anytime.
Note that "If you remove the SD card then the apps transferred into the SD card will not work"
Answer: From the settings you will have to go to storage settings and then you will have to enable the sd card storage which would probably allow you to install all the apps and other downloads easily on sd card nd I would also prefer to buy an card with larger space in it.
Answer: You may put your SD card to another phone. If it doesn't work either,then it means that your SD card may be crashed. In this way, you have to format the SD card and replug it to check it out. Make sure you have tick " Save new apps to SD card"option on your phone. Hope this can help you.
Comment: *"insufficient space"* message is caused by altogether different things. See the tag wiki of [tag:insufficient-memory.]


What's the most hardy red fleshed apple for the Pacific Northwest?

Question: I had two wonderful red fleshed apples in Birch Bay, Washington.  We've moved to St. Helens, Oregon and I can't find any here.  I'd love to replace them.  Does anyone know where I might find these and which ones would be the most hardy for this area?
Answer: St. Helens, Oregon is in USDA hardiness zone 8, and Winter Red Flesh crabapple will grow well up to zone 9, and will grow well in your area with irrigation. This is a very attractive small tree, with bronze leaves, and lots of pink/purple flowers in spring.
Answer: If you want an actual apple rather than a crabapple, check out Pink Pearl (pink fleshed not red), good in low chill areas. Zone 8 isn't high chill, but its not exactly low chill either, so it might be worth trying Xmas Pearman or Grenadine, both with red flesh, though they do require cold winters.


Do Varadero or Havana airports have shops which sell cigars and alcohol?

Question: What are restrictions for cigars and alcohol for departing tourists?
Answer: In Havana airport there is a lot of shops with cigars, alcohol and all the souvenirs, music, jewelry, t-shirts etc. Prices are generally the same or slightly higher than in the city (I think all of the shops are owned by the government anyway). They have generally better assortment before proceeding to the gate. I could pay in some shops with my Mastercard, but not in all of them.
According to www.taxfreetravel.com rules for cigars are

For those wishing to take up to 20 Cuban cigars these is no documentation required.
For those taking up to 50 Cuban cigars – They must be sealed, bearing an official hologram, unopened and in their original packaging.
For quantities of 50 cigars and over. Again they must be sealed, bearing an official hologram, unopened and in their original packaging. You will need to produce an invoice/bill of sale from the place of purchase which itself must be licensed to sell cigars. The total amount of the invoice detailing the amount of cigars must not exceed 5,000 (five thousand) CUC ( Cuban Convertible Peso).
Comment: For the record Varadero airport also has shops for this sort of thing.
Answer: Varadero airport has enough shops which sell cigars, rum, honey, coffee and other souvenirs. Prices for cigars are higher than in the cities. For example, Santa Clara had probably the best prices for cigars - 1 Guantanamera cigar costs about $1.3 while $2 in the airport, $11 for Guantanamera package ($15-$20 in airport), $4 for Romeo y Julieta cigar ($5 in airport). Other prices in the airport - $5.55 for Havana club 3 years, $4 for honey, $3 for chocolate. There is currency exchange service near duty free shops or you can pay in EUR or GBP. Wifi is available with ETECSA card.


How to render the sprites for a 2D soft body physics system

Question: This is not a question as to how to achieve soft body physics, but rather if I have a mass-spring system how to modify a sprite with that information.
I am using unity so I dont have access to vector based graphics.
Answer: If you have a convex shape then what you can do is perform a convex hull operation to get a list of vertices that define the edge. Now find the average position of these points to define the center.
If you already have a list of edge vertices then you can ofcourse skip that step.
These edge points and the center can be used to define triangles as is common in a triangle fan. i.e. the triangles are defined as (center, i, (i + 1) % nEdgeVerts) where i is an index pointing to the next edge vertex. Basically, it's like slicing a pizza.
This needs to be textured, so you will have to set UV values for the vertices. The easiest way I can think to do this is to first set the center point with the uv of (0.5, 0.5). Then find the coordinate of each edge vertex relative to the center. Find the largest value of x and y and scale all coordinates by these values. This will give you X and Y coordinates in the range -1 to 1. All that's left is to do is shift this into the texture UV range, so add 1 and divide by 2.
So roughly;
do for each edge vertex;
<code>  relativePos = edgePos - centerPos;
  if (relativePos.X > largestX) largestX = relativePos.X;
  if (relativePos.Y > largestY) largestY = relativePos.Y;
</code>
then calculate the UV for each vertex using;
<code>  uvCoord.X = ((relativePos.X / largestX) + 1) / 2;
  uvCoord.Y = ((relativePos.Y / largestY) + 1) / 2;
</code>
Now this will work for soft bodies which start as fairly regular shapes like cicles, rectangles etc. And if the UVs remain fixed, i.e. calculate once when the shape is first created, you should actually see the texture bend and stretch with the body.
For more complex convex shapes the UV algorithm above might not be a good fit and you'll have to try some other way, even just presetting the UVs somewhere.
For concave shapes, like a half moon, you will need to do decompose it into multiple convex shapes. See here and here.


Marginally excess size baggage on Emirates?

Question: My luggage dimensions (L+W+H) are 157 cm, only one bag but the maximum size mentioned in the airline (Emirates) is 150 cm. Will this be a problem?what has happened in similar cases,
Comment: Possible duplicate of [Will the baggage be allowed while travelling from India to USA?](https://travel.stackexchange.com/questions/96116/will-the-baggage-be-allowed-while-travelling-from-india-to-usa)
Answer: You may get lucky, you may not - if you search around on this topic (as I did as I was worried about the size of my carry-on), Emirates goes both ways seemingly at random.  For some passengers they are very strict, for others they are lax almost to an extreme.
I checked in at Heathrow a few weeks back for a flight to Australia - my bags were simply put on the scales, rounded down to the nearest pound and then sent through.  My carry-on wasn't even glanced at (and that was the part I was worried about).
The family next to me were checking a veritable mountain of luggage, a lot of it outsized, without issue.
But as we walked away, I noticed someone several stalls down that were getting their luggage measured (and they had smaller bags than I did).
We were in Business class, they were not.  I guess that made the difference...


Ozonolysis Reaction

Question: Why does the starting compound not need an -OH group? I thought ozonolysis only produced carbonyls?
Answer: The product of ozonolysis depends on how you work up the intermediate ozonide. You are clearly familiar with the reductive workup (with dimethyl sulfide or PPh3) that gives two carbonyl compounds, aldehyde or ketone. But if you work up under oxidative conditions, as is the case here, you get carboxylic acids from mono-substituted double bonds and ketones from di-substituted.
Comment: Conditions that oxidise the ozonide, such as hydrogen peroxide as used here, chromate, permanganate or other oxidising agents. Any aldehyde formed would be oxidised to carboxylic acid under these conditions. Google 'Criegee Mechanism' for further information
Comment: Thank you! What do you mean by oxidative conditions?

Ozonolysis Reaction


Whats the public key required for in a transaction?

Question: In figure 1 of the original paper by satoshi, why include the public key of the next owner in the hash?
Answer: The public key belongs to, and identifies, the recipient of the funds. Without it, the network doesn't know who the money goes to, and the rightful owner can't use it.
Comment: Ok, but is that so to speak the same thing like the address of the recipient?
Comment: @TMOTTM: Almost. Technically, a Bitcoin address is a Base58-encoded *hash* of the public key. These days outputs don't specify the actual public key but only the hash. This was only developed some time after Satoshi published the original whitepaper.


How to download multiple proteomes at once?

Question: I'm looking for a way to download multiple proteomes at once from one clade, as fasta. Probably from the NCBI, because it looks more user-friendly than Ensembl, but Ensembl is okay too. In the best case scenario, I would like to constrain the download to a specific clade (eg. Actinobacteria, Chloroflexi etc.), maybe with a specific RefSeq Category (eg. reference/representative genome) or even depending on the genome assembly level. Command line would probably be the best option, but if there's a direct download option it would be nice to know it as well.
Does anything like this exist? Help would be much appreciated!
Comment: The FTP has it: ftp://ftp.ncbi.nlm.nih.gov/genomes/ therein look for the `fa.gz` file
Answer: You could try download-refseq-genomes. It will fetch all genomes from the NCBI FTP server that are in a specific subtree of the phylogeny.
For example, downloading the amino acid sequences from all proteins in each genome assembly for all species belonging to Chloroflexi (NCBI taxon ID = 200795):
download-refseq-genomes.pl -t faa 200795

This will download all assemblies with status=Complete. Use option -a to download all assemblies with any status.
Answer: You can use NCBI resources to download these data directly. For the entire proteome, you can download the sequences of all proteins annotated on the genome assembly in FASTA format. In the NCBI FTP directories, these files have the names with the suffix _protein.faa.gz. More details about the files in the FTP directories are described in the README.
Command-line method using EDirect
This method uses Entrez Direct to first query the Assembly database for all available genomes, parses the output to extract the ftp path and downloads data using wget command.
esearch -db assembly -query 'txid200795[organism] AND lastest_refseq[filter]' \
  | esummary \
  | xtract -pattern DocumentSummary -element FtpPath_RefSeq \
  | while read -r url ; do
    path=$(echo $url | perl -pe 's/(GC[FA]_\d+.*)/\1\/\1_protein.faa.gz/g') ;
    wget -q --show-progress "$path" -P protein_data ;
  done

Here, I am restricting the results to latest RefSeq data by using the latest_refseq[filter] but you can use any other Entrez filters to further narrow down your results. Along the same lines, you can modify the code minimally as shown below to download multiple file types:
esearch -db assembly -query 'txid200795[organism] AND latest_refseq[filter]' \
  | esummary \
  | xtract -pattern DocumentSummary -element FtpPath_RefSeq \
  | while read -r url ; do
    base_path=$(echo $url | perl -pe 's/(GCF_\d+.*)/\1\/\1_/g') ;
    for suf in genomic.fna.gz protein.faa.gz ; do
      wget -q --show-progress "$base_path$suf" -P ncbi_data ;
    done ;
  done

GUI method
You can use the same query as shown above in the NCBI Assembly portal and then use the 'Download Assemblies' button to pick and choose the type of files you would like to download. By default, if you do not select any assemblies in the results, this interface downloads files for all results.


How Do I Restore Chrome Previous Session Tabs from Command Line/Target Textbox in Chrome Properties?

Question: I've tried doing this, and when i open properties for google chrome:
the target box says:   "C:\ProgramFiles(x86)\Google\Chrome\Application\chrome.exe"
the start in box says:
"C:\Program Files (x86)\Google\Chrome\Application"
So If I type in the target box:
"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe --restore-last-session"
And press Ok
a Error shows up with the title 'problem with shortcut' saying 'The name 'C:\Program Files (x86)\Google\Chrome\Application\chrome.exe --restore-last-session' specified in the target box is not valid. Make sure that the path and the filename are correct'
Is there a solution to this so i could reopen the tabs and windows that were closed when my laptop crashed?
Really quite worried about losing any tabs and getting behind on work - I've created a back up on a USB for the default folder in the user data folder.
What happened was that my laptop crashed and i reopened chrome but missed the restore button and there was no way to reopen the tabs - I then closed chrome and made sure not to reopen it in case i lost any data and made a back up.
When I saw this method being explained on this website: http://www.tech-recipes.com/rx/3018/google_chrome_force_restore_previous_session_command_line/
^For windows XP this website used in the target box- C:\Documents and Settings\Application Data\Local\Google\Chrome\Application\chrome.exe --restore-last-session (If I use this in the target box then the error still appears)
Q)How could I do this for my Laptop? What would I have to type in the command line/target box so the error doesn't appear and I can restore what was lost?
Advice appreciated
Answer: I think your quotations are in the wrong spot.
Try this:
"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --restore-last-session
Comment: This does not open all windows
Answer: in PowerShell you can simply use
<code>start chrome --restore-last-session
</code>


What does the error 32111 in the Auction house mean?

Question: I was trying to buyout an item on the Auction house and it said error 32111.  What does this mean?  ( Now I have a logged error of it in my completed menu )
Comment: Question should be close as there is no longer an auction house for diablo 3.
Comment: @z- Question should not be closed. See [this answer](http://meta.gaming.stackexchange.com/a/8451/50582) to your own meta question about D3.
Answer: Although I can't find official confirmation, I believe this error indicates that you attempted to buy something that no longer exists.  This generally means that someone else purchased the item in question while you were browsing.
You'll get this error often if you try to buy popular/in demand commodity items (gems, crafting materials, etc), especially when the prices are far below market.  The quantity of people shopping means that there are lots of buyers watching item prices and snapping up good deals.
Although the game will temporarily take your money when this error occurs, I've found that shortly afterwards it shows up on the "Completed" tab as a "Failed" purchase.  In some cases I was able to speed up the refund process by entering and then leaving a game session.
Comment: What's worse than this error is when you try to buyout a commodity item (ie, a gem) at a low price, and the trade is confirmed, but *not for the price you saw in the buyout window!*


Use of "save this day" instead of "save the date"

Question: Can we use the phrase save this day  instead of save the date? The intention is to emphasize an event happening on a special date. For example, a soccer match is going to happen next Friday and I want to say Save this day! Is it correct?
Comment: A hero saves the day.  A guest saves the date.
Comment: What's wrong with *save the date*?
Comment: Nothing is wrong.I just used "save this day" instead of "save the date" somewhere ,so that's why I'm asking.
Answer: Save the date or mark your calendar would be customary. Save this day would be acceptable, but not as common.
I would not use save the day, as that phrase more commonly uses a different sense of save, to rescue or safeguard. If someone were to save the day in reference to a soccer match, I would think of a player who attained victory for the team when defeat was imminent, such as scoring a last-minute goal or preventing a tying goal.
Comment: Just to clarify: "save the day" is a common idiom for rescuing others or turning a defeat for your group into victory. It's not just that that's how Choster would construe an ambiguous sentence. That's the conventional meaning. Like, "Our company was going bankrupt, but then a venture capitalist brought in new funds and saved the day." Etc.
Comment: Thank you Choster. I know "save The day" is for rescuing purposes..wondering if "save This day" has the same meaning or not?
Comment: @Arash: _save the date_ is a common expression; _save this day_ is bound to raise a confused eyebrow or two, even if it IS interpretable in its context. (It initially reminded me of the oft-quoted "choose this day" refrain, e.g.).
Answer: "Save this day" might work if the event is going on for the entire day, and the guests literally will have to save the whole day for your event.
If your function or event is going on for, say, an hour or two, I think "date" would be the more appropriate word, not only because convention tells us so, but because using the word "day" might imply something else - like the event going on for much longer than the one or two hours.
What comes to mind is this example:
"Don't worry, I'll be sure to save that day for you, and only for you."
Versus
"Don't worry, I'll be sure to save that date for you, and only for you."
The first would mean that you're putting aside that entire day for that person.  While in the second one, it sounds a bit more ambiguous because it could just mean a dinner date, or it could also mean the whole day.
Answer: Why not use plain English and simply announce the event?

We are happy to announce our wedding will be next June 10, 2013. Formal invitations with details and RSVPs to follow.
Please join us for the ABC Conference May 13–18, 2014 in Seattle, WA, USA.
The next soccer match is next Friday.
Friends and relatives, wonderful news, our wedding will be on the long weekend in August in 2013 in Smithville, IL. We're sending this advanced notice in the hopes you can plan to join us.

It's implied if someone is intending on attending, they will mark the dates on a calendar and reserve the date anyway. No need to instruct them to "save the date", it's understood (don't treat your guests like they are dummies and don't know what to do).
Comment: Though you're right, "save the date" has become a common cultural expression for event notification 'subject lines' (for a certain category of event)


What is the difference between a service and an application in Sharepoint 2013?

Question: What is the difference between a service and an application in Sharepoint 2013?
Answer: Service applications are different SharePoint features which you can configure and share among different web applications. There are lot of built-in service applications which you can configure and benefit from.
Applications - if you are referring to custom applications, are the one you can develop using Browser, SharePoint Designer or Visual Studio to introduce new functionality into your solution.
Comment: Also useful to note is that 'Application' could mean a generic custom solution (the traditional definition) as Joy indicates, or it could be a specific type of solution called an 'App for SharePoint' that uses a specific architecture, deployment, and management mechanism -- they're constructed, packaged, and deployed using either Visual Studio or the Napa Developer tools and are also only available in SharePoint2013/Office365
Comment: I think the question is the different between Services & Service Applications, not service application & Applications.
Service Application: Service that can serve specific web applications.
Services: running on Farm level and serve all web application once it is enabled
Answer: SharePoint facilitates several services such like user profile, secure token, business connectivity and etc.. which are supported at farm level. An application is a web application where it also lies in the same level as services. There you can add site collection, sites and add content. Then the services come and help those applications to function by facilitating with a set of services.
Basically SharePoint Farm has many service applications and can have many web applications as well.
Comment: This is another good example of how ambigous 'application' is in the SharePoint world -- because the type of application Malin is talking about is not the same as either of the others discussed in Joy's answer (or my comment to it). This version of application (the 'web application') is specific to IIS, not just SharePoint, but any IT Pro that deals with SharePoint will need to understand this definition of application as well!
Answer: Scaling a SharePoint farm is often achieved by efficiently sharing resources across sites running in different web applications and by offloading processing cycles from front-end web servers to dedicated application servers.
In Old version(2007) we have the SSP concept, But from 2010 & onward we have this new service architecture.
In SharePoint 2010, service applications are used to facilitate sharing resources across sites running in different web applications and different farms. The new service application architecture also provides the means for scaling a SharePoint farm by offloading processing cycles from the front-end web servers over to dedicated application servers.
A key benefit to this new architecture is that you can treat a service application as a pluggable component. After a service application has been installed and created, it can be configured for several different deployment scenarios. In simple farms, an instance of the service application can run on each front-end web server. In more complex farms, a service application can be configured to run on a separate application server or in a farm of application servers.
read more Here : http://sharepointpromag.com/sharepoint-development/sharepoint-service-applications
But for the Applications:
If you are talking about the Web Application then
A Web application is composed of an Internet Information Services (IIS) Web site that acts as a logical unit for the site collections that you create. Before you can create a site collection, you must first create a Web application.
Each Web application is represented by a different IIS Web site with a unique or shared application pool. You can assign each Web application a unique domain name, which helps to prevent cross-site scripting attacks.
But if Application means App development.
SharePoint 2013 is a versatile development platform for building apps and solutions with varying scopes that address a wide range of needs. The SharePoint 2013 developer documentation guides you through the features, technologies, capabilities, and models for development that distinguish SharePoint 2013 as a development platform. Our developer documentation walks you through the essentials of writing your first app, getting started working with the platform, and creating, using and interacting with SharePoint 2013 resources in your own code. We provide in-depth articles about SharePoint concepts, step-by-step how-to task guidance, and code samples to help you begin building apps for SharePoint and SharePoint solutions quickly and easily.
http://msdn.microsoft.com/en-us/library/office/jj164084(v=office.15).aspx


Combine external mic and system sound and send output to HDMI

Question: I am looking to combine the system sound with an external mic plugged into the microphone jack and send the combined audio output to HDMI. Is this doable on my Macbook pro. I have tried different things with sound flower and creating aggregate devices and such without luck. I am able to create a recording in Quicktime which has the sounds sources mixed perfectly. But, I want to be able to send this output live through HDMI. Any help is greatly appreciated.
Answer: If you are looking to combine separate HDMI video and audio into a single HDMI connection (to go to a monitor, for example) you need an HDMI Audio Injector
This device is separate from your MacBook Pro and will work with virtually any digital video source and either an analog or digital audio source.
As for getting the sound to/from your MBP, you will need a Mini DisplayPort to HDMI for the video and perhaps a USB Audio Device.  Here are two products I have personally used with good success:
Mini DisplayPort to HDMI
USB Audio Adapter
You hook the outputs up to the HDMI Audio Injector and you should get the results you are looking for.
I hope that helps.
Comment: Thanks for your reply. Let me clarify a little more. The macbook pro is sending out Video and Audio (from youtube or similar program) through HDMI out. I want to add another source of audio (from an external microphone) to the same signal before it goes into the TV to play both the video and Audio. In other words, I need to add a source of two of audio on top of what comes out of the computer before it gets to the TV. More like an opportunity for sound mixing. But, that would mean I have to buy a set of speakers that work with the mixer
Comment: Do you want to do this live?  Meaning you are going to put the additional audio on top of the streaming Youtube as it happens on the fly?  Or is this something that is going to be prepared in advance?  As for the speakers, I don't see why you need speakers that work with a mixer.  Any 4ohm speakers should work.
Comment: Yes, Live. I think I figured this out. I downloaded a program called Audio hijack from Rogue Amoeba and you can define how you want the sound to flow. I chose mic as one input, safari as the second input (all graphically on the app) and chose the HDMI as output and it all works seamlessly. No mixer or speaker


How do I find Pokémon?

Question: After catching my starter Pokémon I've not encountered any more Pokémon, is it entirely random when Pokémon pop up or is there some kind of indicator for me to be on the lookout for?
Answer: If you look around on the map you will be able to see all the different icons such as Pokémon Stop and Pokémon Gyms. If you look closely you will be able to see a "leaf-effect", this indicates that there are Pokémon in that area.
Go there and you will encounter Pokémon.
Comment: "Go there and you will encounter Pokémon." this is not true. See: http://gaming.stackexchange.com/questions/272708/do-these-leaves-signify-anything
Comment: Is there any distance requirement or region locking because I have no icons at all (Pokémon Stops or leaf effects) on my map even after walking 15kms...
Answer: In addition to the other answer, if you see a loading icon (rotating circle) at the top left corner for a long time I recommend killing the app and launching it again.
I had the same issue where nothing would show up, turns out the game lost connection and couldn't sync with the servers.
Comment: @sommerjj I disagree. The user is saying they had the same problem of pokemon not showing up, and it turned out it was a "Lost  connection issue", and that a reset fixed it. Therefore this is an answer to the question.
Answer: Pokemon spawn more often in places that have lots of people (based on Google map data). This means places like malls have more Pokemon than fields or forests. If there are no Pokemon near you, then try visiting a popular shopping center, gas stations, a busy intersection, or any other place where people are likely to use Google maps. You will know that you have found a place where Pokemon spawn when you see a leaf animation. Note that this does not necessarily mean a Pokemon is currently there, only that they regularly spawn there, so it's a good place to look.
You can also use incense to have a Pokemon spawn on your location every 5 minutes for 30 minutes, regardless of your location, but that will require real money to do regularly.

How do I find Pokémon?


As I stand on/at the ______ of a new chapter?

Question: Can someone please fill in the blank for me? I can't remember how the phrase goes. I don't want to say "stand at the start of a new chapter" because that sounds clumsy. I had originally tried "stand on the edge of a new chapter" but that doesn't sound quite right either. Can someone suggest a better word or an entirely new phrase referring to the same thing?
Answer: I believe you are mixing metaphors. The common phrasing "stand on the ..." ends with precipice. But that is for a situation that could become very bad very quickly. A precipice is a sharp cliff, where one wrong move could be fatal but the right moves could leave to safety.
A new chapter of ones life implies change, transition, or new opportunities.
If however you do mean that you are at a point where things could go well or poorly, you could say you are at a precipice, but perhaps you are more standing at a crossroads

Also, at a crossroads. At a point of decision or a critical juncture, as in Because of the proposed merger, the company is standing at the crossroads. This phrase, based on the importance accorded to the intersection of two roads since ancient times, has also been used figuratively just about as long. In the 1500s Erasmus quoted from the Greek Theognis's Elegies (c. 600 b.c.): "I stand at the crossroads."

Drop the "chapter."
Answer: Further context could be of relevance here. Do you mean a metaphorical chapter, like perhaps, a new chapter of your life?
I suggest the following idiom, which you could use depending on how you want the sentence interpreted:
on the cusp

On the threshold or verge of a development or an action

[American Heritage Dictionary]
Thus, you could say—
As I stand on the cusp of a new chapter of life...
Answer: I'd say precipice. Standing on the precipice of a new chapter/era/etc., is a phrase often found in writings in books, newspapers, and so on.
For example:

Alan Wolfe, "Are you better off now?", in the New York Times,

Yet maybe we do not, as he says we do, ''stand at the precipice of a new era.''

Jesse Lawrence, "David Beckham's Final Game Highlights Landmark Season for MLS & MLS Tickets", in the Huffington Post

Still, as American soccer fans stand at the precipice of a new chapter in post-David-Beckham-Experiment MLS history, Becks's influence is still undeniable.

Michelle Goldberg, "New York Lockdown", in the Guardian

Now he talks as if he's standing on the precipice of a new era. "I like what happened in Seattle. But the real vision I have is what happened in Paris in 1968," he says, referring to the student uprising and general strike that convulsed the city.
Answer: I think the standard BE version is threshold

As I stand on/at the threshold of a new chapter."

OED:

1.a. The piece of timber or stone which lies below the bottom of a door, and has to be crossed in entering a house; the sill of a doorway; hence, the entrance to a house or building.
2. transferred and figurative.
b. In reference to entrance, the beginning of a state or action, outset, opening.
1834   L. Ritchie Wanderings by Seine 8   The youth, stepping proudly upon the threshold of manhood.
1877   M. Foster Text Bk. Physiol. (1878) iii. i. 389   We are..met on the very threshold of every enquiry [etc.].

Google search "on the threshold of"


Tool to Preview Photoshop Brush Set (Windows 7/10)

Question: Is there a tool to preview Photoshop brush sets for Windows 7/10? (.abr files.) Google search gave me a few choices for Mac only.
Answer: Photo Brush is suitable for all Windows PC's. System requirements: Microsoft® Windows® 7, Vista or XP (32-bit or 64-bit editions; 1 GHz processor or better; 2 GB of RAM; 1 GB of free disk space; minimum screen resolution: 1024 x 768 (highly recommended higher resolution).


How are range and frequency related in HF communications?

Question: How does the range of HF communications differ with frequency used? Is it less frequency more range, or more frequency less range?
Comment: This is a very generic RF/physics question and is probably better asked on [physics.se](https://physics.stackexchange.com) or [ham.se](https://ham.stackexchange.com). Have you tried searching those sites to see if your question has an answer there?
Comment: I think HF is much more prone to be affected by atmospheric conditions which would then drive the choice of frequency. https://www.met.nps.edu/~psguest/EMEO_online/module3/module_3_2b.html#:~:text=HF%20users%20have%20found%20that,HF%20communications%2C%20but%20not%20always.&text=In%20these%20situations%2C%20it%20is,frequency%20higher%20than%20the%20FOT.
Comment: Related: [What is the night effect?](https://aviation.stackexchange.com/q/36376/14897)
Answer: Neither or both, depending.
Unlike VHF and higher bands, which travel mostly via line of sight and therefore have limited range depending on altitude, HF radio relies on skywave propagation. This means the radio waves travel up, bounce off a layer in the upper atmosphere and then travel back down to the receiver. They may even bounce up and down between layers several times, allowing one to receive signals from the other side of the planet. You may be able to talk to stations far away but not nearby, or the bounces may not work the same in both directions. It's unpredictable.
All of this odd bouncing depends on atmospheric conditions, which vary from place to place and even from hour to hour. Worse, different parts of the HF band will behave differently at the same time and place, so it has been broken up into several sub-bands of frequencies that tend to behave similarly.
That is why oceanic flights are given two HF frequencies in different sub-bands: at least one of them will probably work. Probably. And which one (if any) may change over the course of a long flight!
Worst of all, because of this long-range behavior, every station on the planet needs a unique frequency, and there isn't a lot of bandwidth to go around, which is why it is chopped up into very narrow channels that give horrible sound quality. So, HF is only used when absolutely nothing else will work (or is available).
Comment: While I won't say _weird_ is wrong -- because it is _weird_, a more helpful description would be unpredictable.
Comment: @Gerry Fair enough. Changed.
Answer: HF propagation over long distances depends on the ionosphere, and the state of the ionosphere depends on the sun — it varies with solar activity (which follows the 11-year sunspot cycle), time of year, and time of day.
The two most important layers of the ionosphere are the D-layer (60-90km above the Earth), which absorbs signals, and the F-layer (250-400km above the Earth), which refracts signals back towards the surface. (There's also an E-layer, which I will be ignoring for the moment).
D-layer absorption decreases with frequency, and increases with solar activity (and sometimes increases greatly when a solar flare releases a bunch of X-rays). During the day, and during periods of high solar activity, this absorption can make lower frequencies completely unusuable. At night, the D-layer rapidly fades away, and the lower frequencies "open up" (this is why you can sometimes hear distant AM stations only at night).
F-layer refraction also decreases with frequency and increases with solar activity. The way it works is that signals below a certain critical frequency will be refracted enough to come back down to Earth, but above that frequency they will fail to be refracted far enough, and continue off into space. When the solar activity is high, and the sun is high in the sky, the usable frequency climbs; when the sun sets, it goes back down, but the F-layer doesn't dissipate as quickly as the D-layer, so the result is more of a gentle drop over the course of the night.
F-layer refraction also depends on the angle at which the signal encounters the ionosphere — if the critical frequency is 5 MHz, then a signal going nearly straight up will come back down if it's below 5 MHz, and go into space if it's above 5 MHz. But a signal beamed near the horizon, grazing the F-layer at a much shallower angle and coming down thousands of kilometers away, can refracted even if its frequency is several times higher, say 15 MHz. This causes the curious effect that, when working above the critical frequency, you can talk to places that are far away, but not places that are nearby (unless they're so close that you can hit them with a line-of-sight signal, ignoring the ionosphere entirely).
Plus the ionosphere has its own "weather" conditions, and interacts with the Earth's magnetic field and the aurora in all kinds of interesting ways that would make this post even longer if I tried to explain them.
So in short, there's no straightforward relationship between frequency and distance, and the usable frequency (or frequencies) for a given path depend on the distance between the transmitter and the receiver, where the sun is in the sky in relation to both of them (time of year and time of day), the progression of the sunspot cycle, and a bunch of basically random factors that are difficult to forecast more than a few hours in advance.
As a visual aid, here is a map of (a prediction of) the highest usable frequency between a point in New Jersey and anywhere else in the world; the colors represent the different Amateur Radio frequency bands, which aren't relevant to aviation, but it should still convey the complexity:
Comment: @rclocher3 it's from my own site, prop.kc2g.com. The code is open-source and the underlying graphical toolkit is matplotlib.
Comment: What software did you use to make that nice graphic?
Comment: Very impressive!
Answer: It varies all over the place and depends on lots of stuff- here is a summary.
HF radio beams below about 30 megahertz that are aimed horizontally bounce back and forth between the earth and the ionosphere; so over-the-horizon propagation is common. If you are lucky you can bounce an intelligible signal all the way around the world on 100 watts and if you are really lucky you can do that with one watt or less.
Above 30 MHz the range of your signal becomes progressively more and more line-of-sight (i.e., it stops at the horizon), the beam no longer bounces off the ionosphere, and over-the-horizon coverage stops. In this regime, you get best range by putting your antenna on top of the tallest building or mountain possible, which geometrically puts the line-of-sight limit (i.e., the horizon) further away, thereby increasing the useable range.
Above 50 MHz your broadcasts are strictly line-of-sight and your radio signal starts getting bounced off of big buildings- so if there is a metal building blocking your line of sight, it will also block your radio transmission unless another metal building bounces some signal your way, around the other building. This regime is called multipath and is dominant at and above 100MHz.
Microwaves (300MHz to 300GHz) propagate more like beams of light than like radio waves, and are commonly focused into very narrow beams which have to be carefully aimed in order to hit the receiving antenna. They are also line-of-sight (although they can go through wood and plaster) and need the tallest towers possible to get the best range.
Comment: Though I would note that the degree to which microwaves are line-of-sight varies dramatically by frequency. Certainly, none of them are going to bounce off the ionosphere and reach a receiver halfway around Earth, but a 900 MHz, 2.4 GHz, or even 5.8 GHz Wi-Fi or cellular radio signal will go through normal interior walls without too much trouble and 900M/2.4G will work reasonably well even through normal exterior walls. The same cannot be said for a 30+ GHz signal.
Comment: @reirab, will edit.
Answer: HF radio waves, which have frequencies between 3 MHz and 30 MHz, propagate beyond line-of-sight by bouncing off the ionosphere.  The ionosphere is in the upper atmosphere, and it's made up of several layers of particles ionized by the sun.  One layer, which is called the D layer, scatters radio waves in all directions, which has the effect of absorbing radio waves.  The D layer only exists in daylight hours.  (You can't hear far-away AM radio stations in the daytime because the D layer scatters the radio waves.)  There are also the E and F layers, which bounce radio waves.  (To say that the waves "bounce" is an oversimplification; the waves actually refract.)  The E and F layers are strengthened by sunlight, and are weaker at night.
At any given time and place there is a maximum frequency, called the Maximum Usable Frequency (MUF), that radio waves will refract off the ionosphere.  Radio waves at frequencies higher than the MUF won't refract, but will instead radiate off into outer space.  Radio waves at frequencies just below the MUF tend to refract further than waves at lower frequencies.  The MUF changes quite a bit between nighttime and daytime.
The sun goes through an eleven-year solar cycle; at the peak of the cycle there are more sunspots and more ionizing radiation that energizes the ionosphere, and at the bottom of the cycle there are few or no sunspots and less ionizing radiation.  Where we are in the current solar cycle also has a large effect on the MUF.
Lightning produces a burst of noise across many frequencies, but especially at the lower HF frequencies (frequencies lower than about 10 MHz).  Lightning happens many times per second worldwide.  Radio noise from lightning propagates by refracting off the ionosphere just like manmade radio signals.  Noise from lightning makes use of the lower HF frequencies difficult when there are thunderstorms within radio range.  In my experience, use of the lower amateur HF bands (3.5 MHz, 7 MHz) is difficult in the US in the summer.
Because of the complex effects I mentioned, and others that I haven't such as solar storms, predicting HF radio wave propagation is a complex task.  Software to predict HF propagation exists, but I know from personal experience as an amateur radio operator that the software does a reasonably-good job of predicting average propagation, but real-world propagation changes varies quite a bit from day to day, and sometimes changes minute-by-minute, so actual conditions might vary quite a bit from predictions, for better or for worse.
Sorry for the rambling background, but as you can see, it's a very complex subject.  To answer your question, daytime HF propagation is more often better than nighttime propagation, but not always.  During both daytime and nighttime, higher frequencies tend to "skip" (refract) further, as long as the frequency is below the maximum usable frequency (MUF), but not always.  For someone who doesn't know much about HF propagation trying to contact another station on a short list of HF frequencies, I'd suggest to try the frequencies in order from highest to lowest.
Comment: I forgot to mention lightning noise in my answer, but yes, it's a very significant effect, especially in the tropical regions.
Comment: Yes but you remembered to include a graphic @hobbs ;)


LED track lighting question

Question: i had 4 Par38 75W bulbs on track.
replaced them with 4 led 13W bulbs.
all work but last one .
i tested bulb on another fixture works  fine.?
when i put old "incandescent" bulb in last one all works fine
the track is on dimmer and all bulbs dim except when led is in  last fixture
is there limit of led on track?
thanks
Comment: What make and model are the new bulbs and the dimmer?
Answer: You're saying "last one", but that has two meanings.  First as position: the last one in the row.  Second as time: the last one remaining.
The second meaning is relevant here.   What's actually the case is all 4 sockets are wired the same.  What's causing the problem is removing the last (final) incandescent.  It wouldn't matter if you removed it from position 2, 3, or 1.  Once there are no incandescents left, the problem occurs.
The root problem is one we are familiar with here, and has many, many Q&A.  The short answer is a bad dimmer, a bad choice of LEDs, or a combination of the two. For LED dimming to work, you need both dimmable LEDs and an LED friendly dimmer.  Assuming you bought these LEDs prudently, it's time to look at the dimmer.

LED track lighting question


What are some sources I could use to get to a decent level to be able to analyze advanced classical pieces?

Question: I love Mozart, Bach and Beethoven, Chopin and I just want to be able to understand even more by analyzing them. Does anyone know of a good source for me to study to be able to get to a level where I could analyze such advanced piece?
Answer: Here is a great site for Chopin: http://www.ourchopin.com/
The Work List on the side shows his works and is organized by type of piece (etude, bolero, sonata etc.) There is an analysis on each piece.
I find the Etude Magazine kind of useful as it provides insight to the musician, it is a little difficult to navigate though the pages.
Answer: You will find a great deal of excellent material here:
Robert Greenberg,PhD
How to Listen to and Understand Great Music, 3rd Edition Audiobook
Robert Greenberg - Beethoven's Piano Sonatas
And much more...
Or here - same material, different outlet and more variety of formats (wait for the sales):
Professor Robert Greenberg, Ph.D.

Dr. Robert Greenberg is Music Historian-in-Residence with San Francisco Performances. A graduate of Princeton University, Professor
  Greenberg holds a Ph.D. in Music Composition from the University of
  California, Berkeley.  He has seen his compositions—which include more
  than 45 works for a wide variety of instrumental and vocal
  ensembles—performed all over the world, including New York, San
  Francisco, Chicago, Los Angeles, England, Ireland, Greece, Italy, and
  the Netherlands. He has served on the faculties of the University of
  California, Berkeley; California State University, Hayward; and the
  San Francisco Conservatory of Music, and has lectured for some of the
  most prestigious musical and arts organizations in the United States,
  including the San Francisco Symphony, the Lincoln Center for the
  Performing Arts, the Van Cliburn Foundation, and the Chicago Symphony.
  For The Great Courses, he has recorded more than 500 lectures on a
  range of composers and classical music genres. Professor Greenberg is
  a Steinway Artist. His many other honors include three Nicola de
  Lorenzo Composition Prizes and a Koussevitzky commission from the
  Library of Congress. He has been profiled in various major
  publications, including The Wall Street Journal; Inc. magazine; and
  the London Times.

Some have problems with Greenberg's style of delivery, but even if you don't care for it, IMO it's well worth suffering through, because of the breadth and scope of his knowledge and his ability to teach and explain.


Is it possible to determine when an answer was accepted?

Question: I don't see an obvious way to determine the date and time
Answer: Check the mouseover (tooltip) of the green accepted symbol.
Comment: Can't access this on a tablet...
Answer: In addition to Loong's answer, you can also use the timeline view. This has the advantage of always showing the full date and time; the tooltip uses the same relative timestamp (e.g. "yesterday", "n days ago") used in most other places on the site, but you can't hover over a hover text (the way you can to get the more precise time in other cases).
The information on acceptance lives on the timeline for the accepted answer; for example, on Who played Hedwig?, the tooltip only says that the answer was accepted "two days ago":

But the timeline of phantom42's answer shows the full date and time:

This screen is a bit hard to get to; if you have GreaseMonkey or TamperMonkey installed, you can use this userscript to add a link to every post1:

You can also get here from the question's timeline; the time each answer was posted is recorded there, and includes a link to the answer's timeline:

You'll notice that the (currently) accepted answer is marked by a green checkmark.

1 Note that I'm using another UserScript to add a "revisions" link to each post; you don't get that for free with the script I've linked to here
Comment: @ThePopMachine It's really poorly-advertised; apparently it's considered a failure internally ([according to animuson](http://meta.stackexchange.com/questions/126447/add-a-link-to-the-timeline-of-a-post#comment547988_126447))
Comment: @ThePopMachine Well, I guess there was enough interest to give it a spit-shine
Comment: This is great,  and I'm glad it wasn't something blatantly obvious.
Comment: I think it's awesome.   That shouldn't be considered a failure.   I would read things in this mode.


What is this little, spiky tree?

Question: A friend of mine is moving out and he left me his little tree. Nevertheless, I do not know what kind of tree it is, and I'd like to know so I can google some tips of how to take care of it.
Answer: It is Dracaena marginata. Very easy plant. It needs a little bit of water, not too much. I water it weekly. And light, but it can handle shade as well.
Your plant may benefit from a larger pot, repot it with fresh soil.
Comment: The plant will survive both direct sunlight and shade. But direct sun light will give you a healthier looking plant, so if you can give it some direct sun light, I would advice you to do that. However, too much light can also cause burn. So a little bit of direct sun light, but not whole day would be best.
Comment: Morning or evening sunlight only... it doesn't  like to be in a lot of sun, especially not  in the middle of the day, but  really, they prefer very bright daylight, not direct sun - but will grow in shadier situations.
Comment: Well, I'm in Denmark, so a burn or too much direct sunlight will _definitely_ not be a problem. :D
Comment: Great advice, thanks! I don't even need to google anymore now. :D
Just one more question - is it better to be on direct sunlight? Just so I know whether to put it right next to the window or if it can stay where it is now (it's still very bright in there, as you can see, but direct sun rays don't fall on it).

What is this little, spiky tree?


Upload file from One drive into SharePoint Online Site

Question: Need to upload files from one drive to SharePoint Online Site without copying them into Desktop.
How is this possible ?
Answer: Using SharePoint Online, you can achieve this very easily. SharePoint online and One Drive provides you Copy To functionality in your library.

Using this you can easily copy paste your documents from One Drive to SharePoint site you have permission to.
You can use this link for further reference :  Copy files and folders between OneDrive and SharePoint sites
Answer: Yes, as Ankitkumar said, you can use copy to function to copy files and folders between OneDrive and SharePoint sites.


How can I murder with a No Crime morality follower without them turning against me?

Question: I'm playing Skyrim on the PS3, and I have Uthgerd the Unbroken following me, who will attack me if I commit crimes against residents of Whiterun. Is there a way I can kill people without her attacking me? Because I really want Nazeem and the Talos preacher guy dead, but I don't want to have to either kill Uthgerd, or make her go home every time I want to murder someone.
Comment: bucket on head.
Comment: Nazeem on the other hand yeh, give that pretentious b****** a good arrow to the knee/knife in the back
Comment: come on, give Heimskr a break, sure he can get annoying with his preaching of Talos but he isn't a Thalmor boot licker like everyone else.
Answer: Uthgerd will only turn on you if you're caught committing a crime (gain bounty). It's not a problem if Uthgerd witnesses it as long as it's not detected (seen/heard) by other NPCs. Here are a few things you can try:

A frenzy spell does the trick for me.  Once they're frenzied you can kill them in view of everyone or let other NPCs do it for you. Spell casting is silent with quiet casting (illusion perk).
Knife them in their sleep. Dagger attacks are silent.
Bow sneak attacks work but are not silent like the above methods.

I've tested all this in game to confirm that Uthgerd does not go hostile. Good hunting.
Answer: You can ask your follower to wait in a location(breezehome). Kill Heimskr, get rid of your bounty, and ask your follower to follow you again.
Comment: @ヴァイシャリ Heimskr is the Talos priest in Whiterun.


What's the simplest way to get arduino functionality?

Question: I want to control a servo with the least amount of components. But generally, what is the simplest way to do this without actually using a fullblown arduino board?
Comment: You can [control a servo with just a basic 555 chip](http://www.instructables.com/id/Drive-Servos-with-a-555-timer-IC/)
Answer: If you what you're looking for is the cheapest option with the fewer components possible, then you can use a regular ATMega328p chip, with a few passive components attached to it.
You just need to program it with an Arduino Bootloader once, in order to be able to program it easily, but you can use any existing Arduino to do that. After doing this once, you can program it with any FTDI-type USB to Serial converter.
Here's an Instructable that explains the whole process.
Comment: Since you need some sort of programmer in order to write the bootloader out, you're usually better off bypassing the bootloader altogether and sticking with the programmer. This will also free up any flash that may have been used by the bootloader as well.
Answer: Please, take a look at this guide by Nick Gammon, which explains in detail how to build a breadboard Arduino.
You'll need also an Arduino board without the chip (a good UNO will do the job) because you need to program it some way. It is needed absolutely in the case that you buy an ATMEGA328 that hasn't the bootloader, as you'll have to write it on the blank chip.
To speak directly via serial with the standalone Arduino (and to program it), I suggest you to buy a FT232RL board (just be careful to buy a real one, as there are fakes that FTDI blocked and bricked with drivers)
Then, for the servo you just have to plug it correctly: two cables for power, one for the control.
Answer: This is useful if you don't need all the I/O of the Atmega.
If you want a simple board just to run a servo or two and still have some I/O you could use a ATTiny85 chip and use this software servo library that works with the attiny. It also works best with the High-Low tech cores.
I used this with a project and it works flawlessly without stalling.
This would give you small setup as you can use the internal clock 8MHz and minimal external components, i.e. regulator and Capacitors.


Encopresis frustration

Question: I have a 6yr granddaughter that has encopresis. It's very hard to watch her mom ( a single, working mom) deal with this every day. The little one tries but it is a constant struggle. With doctor visits and different medications it still goes on. It is good to know that there is a diagnosis but with everyday life it is an on going battle. After reading many of the comments on line ,I do feel we are "Blessed" to have a little one that really tries. The problem that I see is the different schedule of each day. My daughters job (different hours) and a busy life in general are very frustrating. I am very Greatfull that "this" is the only health problem that this little one has... however I wish there was a magic pill.I would appreciate any support or suggestions.
Comment: Have you searched the site for advice on encopresis? It is a common question here. Please have a look at the questions and answers, and if they don't help you, please edit your question asking for more specific advice. You can search the site by using the search function (the magnifying glass) or by the tag "encopresis" under your question or the title. Thanks, and welcome.
Comment: What does her pediatrician say? "Encopresis" may be a diagnosis, but it's really just a symptom--of what we don't know here.
Answer: I am a psychologist, not a doctor.
There is no any magic pills. You have to find reason of encopresis and then find a way to dismiss that reason, or make it less severe.
There are several possible reasons I can think of:

sphincter dysfunction. - What you should look for, how to strengthen the sphincter. Maybe some exercises.
Fecal type - this is normal or liquid. If it is liquid - you might get some result if you focus on what the little ones eat.

If from medical point of analyzing everything is functioning right - then psychological reasons might be:

Baby wearing diapers, instead of using pot (or using it rare at age arround 3 years). The way is to begin learning how to use it again - it will take a lot of time now - but this is the way.
It also may be a way to make mother care more for her. Then try to make some more activities with mother which should become stable(everyday, every week) and not connected to encopresis.

Tips that can help:
Care of WHAT child eats - that can help him (her) body to work better.
Care of WHEN child is eating - make her eat in certain time(for example 14.00 everyday). That might help to count a time when going to the toilet will be needed. For grown up full circle eating-toilet is around 4 hours. You can measure time for your child. Time also will depend on what was eaten - if it is something easy to digest - time will be shorter, if it is smth hard to digest - time will be a bit longer. That also can help in controlling process, after some time child will be waiting fecal coming in certain time.
Fix time that child can spend with mother, except time when encopresis occurs.

Encopresis frustration


Is a secular New Year tree considered OK?

Question:
This question presupposes that celebrating secular New Year's Eve in the first place is OK. I looked here: " Is it ok to celebrate New Years Eve? " and the answers seemed not fully resolved, but my reading of them is that it is not forbidden.

Having said that, for many people New Year is associated with the New Year tree (which is a spruce/pine tree). Is that part of New Year celebrations OK for a Jew?

One one hand, the origin of New Year tree is almost certainly/clearly that of a Christmas tree, which to me would definitely seem problematic at best.

On the other hand, for many people (for examples Jews raised in USSR, where Xmas wasn't celebrated for close to 100 years), the tree is 100% firmly and surely only associated with secular New Year, without any connotation of Xmas.
Comment: Related: http://judaism.stackexchange.com/questions/51071/new-year-eve-fireworks
Comment: Even the "secular" new year is based in Christianity.
Comment: @Scimonster - considering that the actual calendar is based on pre-Christian Roman one, I'd appreciate a citation of that?
Comment: "The order of months was January to December in the Old Roman calendar during the reign of King Numa Pompilius in about 700 BC, according to Plutarch and Macrobius, and has been in continuous use since that time" (Wiki)
Comment: @Scimonster - Also, see the first paragraph here specifically about Orthodox Christian calendar, especially applicable to fUSSR: http://en.wikipedia.org/wiki/New_Year#January
Comment: Related: http://tabletmag.com/scroll/157346/why-soviet-jews-have-christmas-trees
Answer: This is almost certainly Ḥukath HaGoyim. Please see the answers there for more information on what makes something fall into that category, but in general, anything done with either no obvious origin (and no logical basis) or an idolatrous basis is prohibited.  Debate about the permissibility of marking the first of January as the start of a new calendar cycle aside, standing up and decorating a pine tree for that purpose would seem (to me) to be squarely in that zone.
No source about this particular practice; sources for the general terms of the prohibition available at the linked question and its answers.


Competitor asking for me to sell my free product

Question: Ok, so another person has a paid product and I have produced a product that is very similar and nearly as good as the paid product. The creator of the paid product has personally messaged me asking for me not to release my product for free and instead I should charge money for it. I believe he is asking me this because he is afraid I will effect his sales. So my question is, should I go with what he is saying and sell the product because if I released for free I would effect his sales? I don't really know I just thought I'd ask and see what I should do and see if this has happened to anyone else before.
(Btw, the 'product' mentioned above is a form of 'software', I don't feel it is necessary to go any more in detail)
Comment: I'm closing this question as off-topic because it's a question about *business*, not a question about *the workplace*.  I don't know if there's another SE site where it would be on-topic (doesn't seem like it fits Freelancing either), sorry.
Comment: Sell it to him/her or do whatever you want. I upset and put 100's of cowboys who made a good living doing substandard rubbish with no qualifications out of work by releasing free software that did their job better than they did, They tried to get it banned, they complained to AG's office and even to the king who called me to come and explain myself. I couldn't care less. But if they'd offered to make me rich by buying it, that might have been different ;-)
Comment: Ask him the rate at which he wants you to sell your product, then sell it to him at that rate. Problem solved.
Comment: Remind him that price parity could also be achieved if he changes his price to match yours.
Comment: If you were to sell it, are you prepared to put in lots of work to made your hobby a business? Documentation, including help files, slick GUI, new features/feature requests, fast turn round on bug fixing, etc, etc? Like most people, I will put up with "rough & ready" if it is free & mostly gets the job done. That changes when I have to pay for the software.
Answer: There are a lot of good reasons I can think of to opt to monetize a product you've created, but "because my competitor asked me to" isn't one of them.


How do I bypass the Verizon activation on a Samsung Fascinate?

Question: I want to use a Samsung Fascinate (model SCH-I500) in WiFi only mode for development and testing purposes. The device has been factory reset and boots to the Verizon activation screen. How do I bypass activation? Do I need to root the device?
Comment: You used to be able to bypass the activation screen by tapping in all four corners of the screen (start in the top left and work clockwise from there). Don't know if it still works, but you could try that.
Answer: After doing some additional research I finally came across a YouTube video on how to bypass a Samsung Galaxy S Continuum activation screen. The steps outlined in the video are very simple:

From the Activation Screen select Emergency call.
Enter the following *#83786633 (*#TESTMODE) which will disappear when you press the last 3
A toast with the text Softkey is enabled will appear
Then press the home button
Answer: Emergency, dial: *#83786633 and a message will pop up saying "Softkey is enabled" then press the home key.
Answer: Install a stock or a custom ROM that best fits your need from, e.g., Samobile or xda. This way you can select the android version and its flavor.


Arduino (Or Raspberry Pi) As HID Device

Question: I have an Arduino Uno and A Raspberry Pi B+. I was wandering how I could use either as a Programbel HID Device (EX: https://srlabs.de/badusb/). The Reason I ask under the arduino section is I want to preferably use it. If not I can use either.
Comment: The Arduino question has already been asked and answered.  As for the pi, it is theoretically possible with a model A or zero to operate the USB as a device rather than host, though I'm not sure anyone has ever done so.  But with models such as the B+ having multiple USB connectors, an onboard USB hub gets in the way of operating in device mode.
Answer: The Uno cannot be used as a HID device through the on board USB. You might be able to use the V-USB Library to be a HID device using the digital IO pins. See this tutorial.
There are several arduino compatible boards that do can act as a HID device natively. Most boards built around the ATMega32u4 can be a HID device.  For example the Arduino Micro
See this question about the Raspberry Pi.
Comment: I would share our experience with V-USB. For educational purposes, we had the opportunity to use like 15+ Arduinos with V-USB (Adafruit Trinket). At the moment, only two of them works well. There are various issues with newer motherboards, Windows 10, and mystic enumeration problems. I strongly recommend going for 32u4, such as Arduuno Leonardo or Arduino Micro (or any similar product with 32u4)
Comment: This answer is not correct in saying that it is not possible with the stock hardware.  The Uno's USB interface is provided by a reprogrammable ATmega8u2 or 16u2, and there are writeups online of how to program that to be an HID device.  Granted, there is the subsequent difficulty of the USB-serial channel not then being available to program the Arduino, though a dual-mode firmware is conceivably possible, if perhaps challenging to use with OSX hosts.
Comment: http://arduino.stackexchange.com/questions/484/arduino-as-usb-hid

Arduino (Or Raspberry Pi) As HID Device


What to do if you made hamotze on something requiring mezonot?

Question: If you accidentally made a hamotze on a food item only requiring mezonot, do you say al hamichya or birkat hamazon for the beracha acharona?
Comment: The bracha achrona is not dependent on the bracha rishona
Comment: Are _m'zonos_ bagels merely an example of something that's _m'zonos_, or is that precisely the food you're asking about? If the former, you've picked [a poor example](/q/3248), and I recommend [edit]ing it out. If otoh the latter, then I recommend editing to clarify that that's the food you're asking about specifically, and why it's worth asking about specifically.
Comment: @CashCow That's not true of all mezonos things. Only pas haba b'kisnin.
Comment: If you eat a "whole meal" of it, that satiates yourself, it requires Birkat Hamazon according to most authorities. Possibly all of them, just they may differ on the quantity.
Answer: I asked my rav (who is from Ner Yisrael in Baltimore) and he said that that the bracha on a item is conected to the food that is eaten only. The bracha acharonah is not (in that sense) connected to the bracha rishona. Thus if one makes the wrong bracha rishona, one should still make the correct bracha acharona.
He said that since the bracha rishona and the bracha acharona are separate bodies of halacha, the poskim do not discuss your case.
He also pointed out that the example given ("mezonos" bagels) is incorrect and you should have used cake. For example see What is mazonot? That is, your question is about making the wrong bracha rishona and you are giving a case in which the correct bracha rishona is indeed hamotzi, which would require birchas hamazon (according to many poskim). That example makes the premise of your question wrong. It would have been better to have given an example which is definitely (according to all poskim) mezonos.
He also pointed out that you could have used the example of water or fruit to show why the correct brachah acharona must be made even if the wrong bracha rishona was made and why it is not given as an explicit halacha.
There are discussions as to what must be done if the wrong bracha rishona is made (and how to fix it). However, especially with pas haba be'kisnin (mezonos), the matter is too complicated to put into a post like here and I would probably make mistakes in trying to write about it.
Comment: @DoubleAA the point is that the example undercuts his question by giving an example which many poskim state should be hamotzi and birchas hamazon. To give force to the question, the example should be something that everyone agrees should be mezonos.
Comment: How can an example given be incorrect? Changing his question so you can answer it doesn't mean you answered his question.
Comment: The example doesn't undercut anything. If I gave Matza as the example in the question would that undercut it because Ashkenazim say HaMotzi on it? The intent of the question is very clear, so the question is not undercut nor does it not have force. What's the bigger issue is you should not be telling the OP that his psak about mezonot rolls is wrong. You can tell him it's a minority opinion or something like that.
Comment: @DoubleAA OK ignore the example. THe question is if someone makes the wrong bracha rishona, what is done for the bracha acharona and that is what I answered.


How should one dispose of cut finger nails?  Is it dangerous for a pregnant woman to walk on them?

Question: Is there an Inyan of pregnant women walking over cut nails ex: a nail salon? Also, can I just vacuum up the cut nails from the floor?
Comment: zahava, Welcome to mi.yodeya, and thanks very much for your interesting question! We'd love to have you as a fully-registered member, which you can accomplish by clicking register/login, above.
Comment: Can't cite a source and don't know how serious it is, but I've heard it's because a pregnant woman might mistake the nail(s) for a scorpion and then have a panic-induced miscarriage. Presumably this wouldn't be a problem if one is not accustomed to having such a concern or if one is very far along in the pregnancy and due any minute.  Having said that, I make a practice of wrapping up the cut nails in two tissues and flushing the wrapped bundle down the toilet, as was suggested to me a very long time ago.
Comment: @SethJ: One problem with this explanation. The Talmud in Moed Katan 18A - http://hebrewbooks.org/shas.aspx?mesechta=12&daf=18&format=pdf - says that the issue only applies if one leaves them where they dropped when they were cup. If one moves them, there is no longer an issue. (The Shulchan Aruch HaRav 260:4 brings this as well - http://chabadlibrary.org/books/adhaz/sh/sh2/1/260/4.htm). If the problem is as you said, what difference would it make whether or not they were moved. It would only matter if the woman could step on them or not.
Comment: @Menachem, off the top of my head? Maybe that suffices for the Takanah because someone conscientious enough to move them would be conscientious enough to let someone walking over them know that they are nails? Again, I don't know the source of the idea.
Comment: @SethJ: What if he's no longer there? It doesn't seem to indicate anywhere that the danger dissipates once he leaves. It would be interesting to see the source for that idea.
Comment: I had a friend who burnt them in a metal tobacco tin lid over the gas flame. It used to smell awful.
Answer: The Mishna Beroura (260, 6) quotes Gemara Nidda (17a) disapproving someone who would throw nails on the highway after cutting them.
Indeed, a pregnant woman could step on them and lose her child.
Gemara's conclusion :

the one who burns his nails is a 'hassid
the one who buries them is a tzaddik
the one who throws them is a racha'

The practical advice is to throw them in the toilets because with modern ones it's considered as being buried.
Comment: Do people in between the gemara and the mishna berura quote this practice approvingly as well?
Answer: Yes, Zahava, the gemara in Moed Katan 18 says that walking over nails can cause a woman to miscarry.  One reason given (Be'er Hetiv/Tola'as Ya'akov) is because Chava caused the loss of "full-body nails".  As  a consequence, women are put in danger by the nails which remained on the fingers and toes.
The gemara gives options of how to dispose of them:

You can dispose of them into a place where they will not be walked on.  This is referred to in the gemara as "burying them".  Also, the gemara has R' Yochanan throwing them in the study hall, since women don't go there.
A better option is to destroy them in a way that there is no chance of them doing any more damage.  This is referred to in the gemara as "burning them".
Transfering the nails into a different "area" than they were originally also takes care of the issue.  The case in the gemara was from inside to outside.

Vacuuming them would certainly fulfil the 2nd option.  I'm not sure how far the 3rd idea goes and whether it would apply from one area to another area in the same salon.
Comment: See the MB 260:6 - starting http://hebrewbooks.org/pdfpager.aspx?req=14171&pgnum=64 and continuing http://hebrewbooks.org/pdfpager.aspx?req=14171&pgnum=65 . He brings the Perisha who says that it is enough to move it from the place it fell, then brings the Elyeh Rabbah who says that it may only be sufficient if it leaves the room it fell in.
Comment: @Menachem, Y"K.  Unfortunately, there is still no hachra'a.
Comment: Yes, but it is stronger to say I don't know because different Rabbis have different opinions and there isn't a clear resolution, than to say I'm not sure how far the idea goes.
Comment: @Menachem, true.  I was referring to the question still not being answered practically.
Comment: rabbi elephant from ou daf yomi on that gemoro explains the another reason that cause a woman to miscarry and explains "walking over" as seeing and that when she sees she gets disgusted,


ESTER replacement for EONIA/EURIBOR

Question: Does anybody know what impact the replacement of EONIA with ESTER ( Euro Short TErm Rate ) will have on discounting existing or new derivatives once EONIA will be restricted as of Jan 2020? I'm interested in curve construction and how the eventual basis will be taken into account. Are there any papers discussing this topic that anyone can share?
Answer: I believe that Eonia can still be used for discounting derivatives after 2020.  Article: https://www.risk.net/derivatives/5848051/esma-eonia-can-be-used-in-csas-after-2020
If it becomes illiquid, counterparties can repaper csa's to Ester.  That will cause an economic effect if there is a non zero Eonia/Ester basis.
Comment: What about projection curves? Will we return to a single curve type paradigm on OIS/ESTER?

ESTER replacement for EONIA/EURIBOR


Setting up lighttpd to run Wallabag

Question: I am trying to set-up lighttpd to have a vhost pointing at wallabag installation. Currently I have not made many changes from the default lighttpd.conf apart from to change the server.document-root to "/var/www/wallabag/web". With those settings when accessing the server IP I get an idex of the files contained in /wallabag/web rather than it automatically loading app.php. If I click app.php the app will load fine and work, but wanting to have it load by default.
If I change the lighttpd.conf to then include app.php in the index-file.names I get a 404 - Not Found error. The reason for this appears to be that it tries to load myserver.example/login whereas with the other configuration it goes to myserver.example/app.php/login.
I am assuming there is something minor I am missing from the settings but I can't find an answer when searching.
For reference it is a Raspberry Pi 2 with the jessie version of raspbian that lighttpd is installed on.
Thanks in advance for any help or suggestions.
Answer: Managed to work out the solution:
<code>server.modules = (
"mod_fastcgi",
"mod_access",
"mod_alias",
"mod_compress",
"mod_redirect",
"mod_rewrite",
)
server.document-root = "/var/www/wallabag/web"
server.upload-dirs = ( "/var/cache/lighttpd/uploads" )
server.errorlog = "/var/log/lighttpd/error.log"
server.pid-file = "/var/run/lighttpd.pid"
server.username = "www-data"
server.groupname = "www-data"
server.port = 80
server.follow-symlink = "enable"
index-file.names = ( "index.php", "index.html", "index.lighttpd.html")
url.access-deny = ( "~", ".inc" )
static-file.exclude-extensions = ( ".php", ".pl", ".fcgi" )
compress.cache-dir = "/var/cache/lighttpd/compress/"
compress.filetype = ( "application/javascript", "text/css", "text/html", "text/plain" )
include_shell "/usr/share/lighttpd/use-ipv6.pl " + server.port
include_shell "/usr/share/lighttpd/create-mime.assign.pl"
include_shell "/usr/share/lighttpd/include-conf-enabled.pl"
dir-listing.activate = "disable"

url.rewrite-if-not-file = (
"^/([^?])(?:\?(.))?" => "/app.php?$1&$2",
"^/([^?]*)" => "/app.php?=$1",
"^/wiki$" => "/app.php",
)
</code>

Setting up lighttpd to run Wallabag