Is APB an antagonist of the mGluR6 receptor?

Question: APB is a glutamate analogue specific to the mGluR6 receptor of ON retinal bipolar cells. It is used in research into receptive field processing by blocking the ON channel. Why is it not called an antagonist?
Comment: I have changed the title of this question to reflect its more restricted scope, corrected the spelling of glutamate — the poster should take the trouble to ensure the spelling of key molecules is correct — and changed "function" to "use in research". It is now in a suitable form for SE Biology, so that it is appropriate to vote the answer of @BryanKrause as correct.
Comment: Of interest
https://link.springer.com: "Are partial agonists antagonists? A key property of partial agonists is that they display both agonistic and antagonistic effects." With BryanKrause: "it's still an agonist". By definition,  any antagonist's intrinsic activity is zero". Agonists may be - partly - antagonistic. No other way round. Slightest effect will make it an agonist.
Answer: APB (2-Amino-4-phosphonobutyric acid) is a metabotropic glutamate receptor agonist, not an antagonist, and in many publications it is indeed referred to as an agonist, so I think your question is somewhat ill-posed. For example:
Yamashita, M., & Wassle, H. (1991). Responses of rod bipolar cells isolated from the rat retina to the glutamate agonist 2-amino-4-phosphonobutyric acid (APB). Journal of Neuroscience, 11(8), 2372-2382.
You can find many many more by searching "2-Amino-4-phosphonobutyric acid glutamate" on Google Scholar.
The reason that APB suppresses ON bipolar cells is because metabotropic glutamate receptors are often inhibitory rather than excitatory. Glutamate is typically thought of as excitatory because ionotropic glutamate receptors such as AMPA and NMDA receptors are non-specific cation channels that depolarize and therefore excite cells. Metabotropic glutamate receptors operate through g-protein second messenger cascades. In ON bipolar cells in particular, there are cation channels that are closed by mGluR6 activation, which therefore inhibits them.
Here's a review article that describes this as well as other basic information about bipolar cell function:
Euler, T., Haverkamp, S., Schubert, T., & Baden, T. (2014). Retinal bipolar cells: elementary building blocks of vision. Nature Reviews Neuroscience, 15(8), 507-519.
Comment: Thank you Bryan. As you can tell from my question I am an interested amateur! My source describes the molecule as an analog for glutamate but its function is to block the G protein coupled receptor and prevent any neurotransmitter action that would otherwise result in the closing of the sodium channels. So, in a sense, the analog is performing the role of an antagonist. This was my confused thinking anyway!
Comment: @adlibber No worries, interested amateurs are good targets for StackExchange sites. :) "My source describes the molecule as an analog for glutamate but its function is to block the G protein coupled receptor" -
 Then your source is either wrong or they aren't actually using 2-Amino-4-phosphonobutyric acid but a different molecule. APB might prevent glutamate from binding the receptor if it is higher affinity than glutamate (not sure if it is but could be), but it's still activating the receptor like glutamate and is therefore an agonist, and it would cause the sodium channels to close.
Comment: OK so its an agonist. Thanks for taking me through it :-)


I just bought a frame off this kid in my neighborhood but don't know who makes it?

Question: I bought this frame off a kid in my neighborhood for 100$. I looked like a cool freestyle frame. I built the bike up and just wanted to know if anybody had a clue to what company makes this frame?
this was on bottom bracket case opposite side of serial # GRREA21
thanks for any and all help.
SG
Comment: there are cut outs on each side of the lower seat tube , and there are 2 slots cut out on the front stem tube and there is a slot cut out on the bottom bracket case in between the serial # and this other # i listed?
Comment: [this one](http://www.vitalbmx.com/product/feature/2013-Eastern-Phantom-Complete,2793) looks pretty similar
Answer: This one is the closest I could find. It has similar head tube and seat tube cut outs. It's titanium though. Is yours titanium? This is the current, steel version. As far as I can tell, this frame is identical, with the same brake bosses on the wrong side of the seat stays. Also has cable stops in the same place for the rear brake. Seat tube clamp is under the seat stays as well, which is another uncommon similarity.
If this isn't the same frame, your frame is almost definitely manufactured by Eastern. The cut-outs on the seat tube and head tube are very common on their bikes, and many of their models seem to have a similar brake placement. The frame I linked to is the only one I could find that had the exact same head tube cut-out.  All the rest had a logo cut out of the head tube.
Comment: I'm also fairly sure it's an Eastern. That company has been on a rocky road but they still answer emails and if you email them the serial number I'm pretty sure they'll answer you. A few months ago I had a bad hub and one of the owners sent me the parts I needed.


How to remove stuck bearing in headtube?

Question: I am trying to service my headset and have difficulties in removing the bearings from the headtube. Those bearings seem to have accumulated some dirt over time and are feeling a little bit grindy. I suppose I am missing out on something here as the bearings seem to have a really tight fit in the tube and I cannot remove them by hand. I also tried to apply some slight pressure from inside with the wooden handle end of a brush with no success. Is this something special like maybe threaded into the tube? Is it even possible to remove those easily?
Comment: Ok, I figured out the tight fit seems to be normal because the bearings are pressed into the tube when installed. In all tutorials I watched previously the bearings could easily be removed. So is removing the bearings in my case (not having any special tools to press the bearings back into the tube) still an option? What else can I do for servicing as good as possible (just regrease?) and remove dirt?
Answer: You can release the bearings by removing the snap ring holding the bearing race in place. At about the one o'clock position there is a gap in the snap ring, which sits between the grey and the black circles.
A (disposable) knife blade can be useful (thin enough) for prying the snap ring just enough to release it, wear safety specs.
Clean and grease the bearings then reassemble, consider swapping top and bottom for increased life.
Comment: Ah, how did I miss that... Thanks for the tip! Now I've put everything back together, but I'll try that next time.


NFT Not Showing Up

Question: Hello I finished every step of the video tutorial titled "How to develop an NFT Smart Contract (ERC721) with Alchemy - Beginner | Road to Web3" until the part where we go to OpenSea testnet and wait for the NFT to show up. I've checked in Remix and it says I have one NFT, but it has not shown up in either my MetaMask Wallet, nor my OpenSea account.
How can we solve this mystery?
Answer: It is a delay between OpenSea and NFTs

NFT Not Showing Up


What did Geordi mean when he said "And then some" ("Sins of the Father")?

Question: In the episode "Sins of the Father", Riker says that Kurn has the crew on his toes. I get that. But then Geordi says "And then some" which is obviously a response, but is that supposed to be an insult to Kurn?
Comment: Voting to leave open because [meaning of phrases in a SFF work is on-topic](https://scifi.meta.stackexchange.com/q/11626/98028). @HorusKol
Comment: @Jenayah Fair 'nuff
Answer:
KURN: I find the constraints a bit difficult to conform to. Just a short while ago, I had to stop myself from killing Commander Riker. I believe he was trying to communicate the crew's sense of discomfort with my style of command. Under different circumstances, I would consider that a challenge to my authority.
  PICARD: One of the aims of the exchange programme, Commander, is for all of us to learn tolerance. As for my crew, it may be healthy to shake up the status quo occasionally.
  RIKER: The Commander certainly appears to have the crew on its toes
  LAFORGE: And then some. No offence, sir.

"And then some" as an English phrase simply means "that and more" with an implication that it's too much.  Geordi is insinuating that Kurn's style of command not only had the crew ready, but also anxious, which is not necessarily a good thing. In this case, the death threats are part of what is putting people over the edge.
Comment: The 'no offense' part can be interpreted as being for the benefit of Riker. Picard effectively just said "This Kurn guy may be making some necessary changes to get things ship shape around here", to which Riker (who's job it is to keep things ship shape) says "yes...he does seem to be effective", to which LaForge ostensibly agrees. LaForge saying "No offense" to Riker is to let Riker know that Geordi is *not* saying Kurn is doing better than Riker. As FuzzyBoots said, the crew is beyond mere preparedness into abject nervosa
Comment: If you watch the scene, the "no offence" is directed at Kurn, not Riker, as they are all at the dinner table.
Comment: Indeed. It's "Holy crap, this guy has everybody _well_ in discipline right now. I've never seen anything like it. Very effective. Er, no offence boss sorry you're great too actually I like you more because we all kind of hate it right now"


What is the meaning of this site's logo?

Question: I am very interested in understanding the meaning of the logo of this website, which looks like a cone with its brim turned halfway outward back onto itself as if trying to turn it inside out. Is there a one-sentence explanation?
Comment: https://en.wikipedia.org/wiki/Spontaneous_symmetry_breaking
Comment: Related: https://physics.stackexchange.com/q/17944/2451 and links therein.
Answer: The logo is that of the "Mexican hat potential". It arises in the Higgs Mechanism and causes a process known as 'Spontaneous Symmetry Breaking'.  The vertical axis is the value of the Potential, $V(\phi)$ corresponding to a value of a field $\phi$. At the start, suppose that there is a particle at the centre sitting on the tip of the 'hat'. Any rotation will result in the same situation, so it is said to be invariant under rotation. Symmetry is broken by the fact that the maximum in the centre is not stable, and any small perturbation around it will result in a lower potential energy, known as the vacuum potential. So this supposed particle (The Higgs boson) goes into this lower energy state, and in doing so breaks the symmetry. At this point any rotation will result in a different situation (unless it is rotated by a full turn).
Before symmetry is broken a particle will have terms that look roughly like $$m\bar\psi\psi\phi$$ where $m$ is  a coupling constant, $\bar\psi$ and $\psi$ are fields of a particle and its antiparticle and $\phi$ is the Higgs field. This describes an interaction between three fields. When symmetry is broken the Higgs field can be rewritten as $v+h$, where $v$ is the vacuum expectation value, and $h$ is a new field. So this can be rewritten as $$m\bar\psi\psi\phi=m\bar\psi\psi v+m\bar\psi\psi h$$ The $m\bar\psi\psi h$ term is just another interaction between three fields, however $m\bar\psi\psi v$ is the interaction between two fields (those being of a particle and its anti-particle), which is known as a mass term. So by coupling with the Higgs field the particle and its antiparticle have gained a mass term, so it can be said that they have aquired mass.


Exporting procedurally textured models for game engine

Question: Recently I created a model which was texured procedurally. I used noise texture to texture the model and also combined it with a bump and Vorenoi map to add extra geometry to my model. On exporting the model neither my texture nor my geometry was preserved. Different export formats rendered different results but none of them preserved the texture or geometry. Is there a way around this problem.
Comment: Are you asking how to bake textures? Or are you asking if there is a way to export the node setup? Or something else?
Answer: Blender's node system cannot be exported since the 3D formats aren't able to store them and the game engines do not have nodes that are equivalent to the ones found in Blender.
What you need to do is bake your textures. Generally for game models you start with a high poly, detailed model from which you create the low poly version that can be used by the game engine (or several for different level of details - LODs). Part of the process is baking the normal map and PBR textures in order to get as close as possible to the look of the high poly model while keeping the polycount low. This is to ensure good performance of the game and keeping vertex budget for hero props (a building in the distant background doesn't need as many polygons as the model of your main character).
Comment: [This tutorial](https://youtu.be/YsXe11YA7AM?t=311) by Aidy Burrows may help you get started if you want to use Blender similar to Substance Designer for creating procedural materials.


Logistic Regression and NaiveBayes with infinite dataset

Question: I'm comparing the LR and NB performance on different datasets. And suddenly I am wondering what if we have a big dataset that is infinitely large (at least ensure both models trained to its best??). How would two algorithms work? Usually, LR tends to be overfitting and it requires regularisation. Would in this case it also tend to be overfitting?
Comment: I can make an infinitely large training set pretty quickly: take my one $(x,y)$ example and repeat it infinitely. What assumptions are you making about your infinite training data? The distribution will be more important than the quantity.
Answer:
Usually, LR tends to be overfitting and it requires regularisation. Would in this case it also tend to be overfitting?

I would not agree. Linear regression is a linear model, comparing with popular machine learning models (deep learning model, or boosting on trees) it tends to be underfitting.
In general, more data* (see comments bellow) means more complex model needed. In other words, if we have huge amount of data, it is better to pick a more complex model. And the simple model such as linear model (for both linear regression and Naive Bayes, see How is Naive Bayes a Linear Classifier? ), will "hit a wall" on performance, i.e., underfitting.
*Here more data means more data points/samples/instances, NOT features/columns.


difference between Visual Studio and RADs?

Question: What is the main difference between a Rapid Application Development tool like MonoDev and Visual Studio, is an RAD more focused on one thing?  I'm looking to make a web application, are there advantages to using a Web Based Rapid Application Development Tool as opposed to Visual Studio with the .NET framework 3.5 support?
Answer: Both are RAD tools. The main difference is Visual Studio is created by Microsoft and, in many ways, has more bells and whistles. Technically, you can use it for mono, but if you want to target both Linux (etc) and Windows with Mono, you may find MonoDev an easier ride. It really depends on what you are doing. At minimum, you will have some re-referencing if you move .NET code to mono.
Comment: What do you mean by this? Mono supports the same references as the .NET runtime. Assuming you don't use any classes not implemented by Mono, and other Win32isms like PInvoke, you should be able to run a VS compiled binary on Mono without any trouble.


Is a comma required when we begin a sentence with a gerund?

Question: Is there a rule that states if a comma is needed in the following case:
Doing this, does that?
The following sentences made me ponder on it:
Clicking on a job within a project(,) opens the page where the button is located.
Cloning a job(,) allows you to set new settings.
Comment: No, those commas you've placed in brackets shouldn't be used.
Comment: *Running can be strenuous.* There's a gerund without a comma.
Comment: @JasonBassford I really struggle with gerunds! I thought a gerund had to function as a verb in the sentence (as well as functioning as a noun), but in your example there's no verb function. If it was *running a race* (takes an object) or *running quickly* (modified by an adverb), it would indicate a verb function. Am I misunderstanding this? Is there a useful resource you rely on that might guide me?
Answer: For the example sentences, no.
In general, it depends on what role the gerund phrase takes.
If the gerund begins a phrase functioning as an adverb, then yes on the comma.
Reading your sentences, I do not advise using a comma.
Source for using a comma after an introductory adverb phrase
If the gerund begins a phrase that is the subject of the sentence, as in your examples, then no comma.
Beginning a sentence with a gerund does not always require one to use a comma.
In your examples, the entire phrase before each "(,)" is the subject of the respective sentence.


What parts of the regular Linux graphics driver architecture is used in Android?

Question: For example, could the Nouveau driver be used and provide hardware accelerated drawing when Android is compiled for x86?
Comment: Sounds like a question about Android architecture and drivers, rather than programming, so I'm pretty sure it is on-topic here. Whether there's anyone that knows Android at a low enough level to be able to answer is a different question, I know I don't know the answer.
Comment: I don't think this question is on-topic here. This is a site for Android *users* as opposed to Android developers. [See the faq](http://android.stackexchange.com/faq) for details what questions are considered on-topic here. You might have better luck on Stack Overflow, and in that case a mod can help you with migrating it.
Comment: Isn't the nouveau driver specifically for Xorg, which isn't/can't used for Android?
Comment: I agree with @GAThrawn. It's not a _great_ fit, but it's not explicitly off-topic.
Answer: Noveau is a driver for the X.org graphics system so it definitely couldn't be used verbatim. The one part that I'd expect to possibly be useful would be the code that actually talks to the hardware. The same is true for any other X.org driver.
But in Noveau's case, most of the work is in reverse-engineering the hardware interface as Nvidia refuses to release the documentation. This work could definitely be reused in a hypothetical Android Nvidia driver.
Answer: Almost none of the regular Linux graphics architecture is used on Android (that is, Mesa, XWindows, etc). Driver developers can choose to reuse major portions of their drivers, but there is a lot of plumbing involved to get drivers to work with SurfaceFlinger (and gralloc, and the Hardware Composer), including 3D rendering as well as display output (HDMI support, etc.).


How to apply inhalable poison?

Question: There are four categories of poison: contact, ingested, inhaled, and injury. I'm interested in inhaled. For example, there's a poison (inhaled) called Burnt Othor Fumes. Let's say I craft some. How do I go about using it in combat?
Comment: Rule #1: Stand upwind.
Answer: FROM YOUR LINK

Inhaled: These poisons are delivered the moment a creature enters an area containing such poisons and do not usually have an onset time. For most inhaled poisons, 1 dose fills a volume equal to a 10-foot cube. A creature can attempt to hold its breath while inside the area to avoid inhaling the toxin. A creature holding its breath receives a 50% chance of not having to make a Fortitude save each round. See the rules for holding your breath and suffocation. If a creature is holding its breath and fails the constitution check to continue doing so, rather than suffocating it begins to breathe normally again (and is subject to the effects of the inhaled poison if still in the area). (Emphasis Mine)

As we can see, it fills a ten foot cube. This does not mean 10 cubic feet, but rather an area 10*10*10.
From there, you either open the stopper (which releases the poison around you), or use it as a ranged splash weapon (which releases it around your opponent).
Comment: This is a strong suggestion. The RAW do not say anything of the actual delivery mechanism. One could argue that it is a 2-component-system, i.e. you need something to deliver the poison with (like a powder, smockestick, pepper pellet,...).

How to apply inhalable poison?


Remap Keypad Ins/0 key to Right Arrow Ubuntu 14.04

Question: The title pretty much covers it... What's the simplest way to do this? I'm currently flipping through the /usr/share/X11/xkb/symbols/us file, but there are a million different section, seemingly for different keyboard layouts or options, under that single file... I have no idea where to go to simply change my Ins/0 on Numpad so that it causes a right-arrow event, instead... (My right arrow key is broken).
Answer: The following solution has worked for me in 16.04 and believe it should be similar.
First of all, why don't you just use the keypad with Num Lock off and use the 4 key as a right arrow?
Anyway, if you want to remap the ins/0 key, you need to do this in the file /usr/share/X11/xkb/symbols/keypad. In there, edit the line
key  <KP0> {  [  KP_Insert,   KP_0    ]   };
to
key  <KP0> {  [  KP_Insert,   Left    ]   };
This will make this work as left with Numlock off
or
key  <KP0> {  [  Left,    KP_0    ]   };
to work with Numlock on. (Quite self explanatory).
Hope this helps


Swedish lemmatization

Question: I am trying to find a lemmatizer for Swedish without any success. Does anyone know anything about this? I am aware for the WordNet in the ntlk package but that's for the English only.
Answer: There's no Swedish model available for it yet (Norweigan is the closest), but keep an eye on Spacy, really easy to use and overall a great tool.
[https://spacy.io/usage/models][1]

Swedish lemmatization


The meaning of adverbs

Question: According to most pages about it on the internet, adverbs just modify the verb and not additional information. Although, I have heard many different replies on this matter and still don't know which one is right. In an instance like, "I played at the park again." at the park would modify played and again would modify played, right? Also, in a sentence like, "I played quickly again." Quickly would modify played and again would modify played, right?
Comment: The relatively uncommon sequence *I played quickly again* would normally be understood to mean that I'd previously played quickly, then did the same thing again later. But the more likely sequence *I quickly played again* wouldn't normally be understood to have any implications for how quickly I played (previously *or* subsequently) - just that there wasn't much delay before I played again. Effectively, it's the position of  ***again*** that dictates exactly what ***quickly*** modifies,
Comment: Just because an adverb modifies a verb, does not mean that **everything** that modifies a verb is therefore an adverb! Also, adverbs can modify adjectives too (among others). E.g. a "really sick patient". "really" is an adverb that modifies "sick".
Comment: It might help if you see that each 'again' showed up away from the verb it modified, and there's a reason for it. Read 'I (played at the park) and I did that again. 'I (played that song very fast) again, as my tutor asked.' Again modifies more than the single verb, it modifies the verb phrase.
Comment: Is this the case with all adverbs such as, "I never eat pickles." with never modifying eat pickles and, "I went into the movies slowly." with slowly modifying went into the movies?
Comment: The traditional view is that 'extremely' is an adverb in 'He drove extremely slowly ... in his extremely fast car.' and 'actually' is an adverb in 'Actually, Albany is the capital of New York State.'
Comment: Note that adverbs may modify verbs, **adjectives**, and **other adverbs**.
Answer: 1) Yes, "at the park" and "again" are both modifiers of "played." The former is an adverbial prepositional phrase, and the latter is a simple adverb.
2) In this case, you are once more correct in your thinking. Both adverbs modify "played," though this is not a phrasing one would often use; a smoother way of saying the same thing would be "Again, I played quickly."
Comment: Okay, but would again modify played or played at the park?
Comment: @Jim: Is a "tall green man" a green man that is tall, or a tall man that is green? That's basically what you're asking. Both "at the park" and "again" modify "played". 1 + 2 = 2 + 1.
Comment: I disagree. @Jim has a point about the distinction. Imagine that on Monday you played at school, on Tuesday you played in the forest, on Wednesday you played at the park, and on Thursday you played at the park again. Here "again" is very much connected to "at the park". But if on Monday you planted flowers at the park, on Tuesday you mowed grass at the park, on Wednesday you played at the park, and on Thursday you played at the park again, now we are modifying the playing only.
Answer: In this case the adverb modifies the prepositional phrase, due to its placement.  Were the adverb to precede the verb, it would modify the verb.
When there are multiple eligible principals to modify, placement is paramount.
Answer: English adverbs don't modify verbs (with the possible exception of degree adverbs). One reasonably well worked out scheme characterizing English adverbs is McCawley's, where clause adverbs are distinguished by the type of constituent they modify.  See chapter 19 pp. 666- of his The Syntactic Phenomena of English, some of which is available on line: SPHE.
I think again is a modifier like only and too which, also following McCawley, have a scope and a focus.  The scope is a constituent establishing a basis for a contrast, and the focus is an item contrasted which is contained somewhere within the modified constituent.

The meaning of adverbs


Changes to theme not being represented in browser

Question: I am currently working on a Magento store.
There is a 3rd party price tag that shows when viewing a product.
The original price is sometimes displayed as plain text next to the image of the product.  When this is the case the 3rd party price tag works fine.  However, sometimes the plain text original price isn't there, instead the price is in a different element, overlapping the "add to cart" button.
When the latter is the case, the 3rd party price tag wont appear (presumably because it can't find a price to display).
I am currently trying to modify the stores theme so that it will check for the presence of the text price tag and if it is not there then instead use the price from the button.
In doing this I'm stuck, it seems non of the changes I make to the theme are showing up when I reload the page.  I've checked to make sure I'm modifying the right theme.
Even just adding a simple div or text block, I'm looking seeing anything come through on the live site.
The data I'm editing is in: app/design/frontend/efv1/default/template
Efv1 is confirmed as the currently active theme.
With normal price tag -
[1]: https://i.stack.imgur.com/VDdXR.png
With normal price tag missing -
[2]: https://i.stack.imgur.com/TgFZx.png
Comment: Clearing Magento's cache was the solution, thankyou
Comment: Have you flushed all caches? Failing that, recompiling the frontend?
Comment: Do you mean my browser or Magento?
Comment: Magento's caching
Answer: Clearing Magento's server-side cache was the solution to seeing the updated site.


QGIS clipper problem when mask used

Question: I have encountered a problem with the raster>extraction>clipper function in QGIS when a mask layer is used.
In the image below the diagram on the left shows part of the original raster.
The diagram in the middle shows the original with one of the red areas overlain by a polygon.
The diagram on the right shows the raster created by the clipper function using a mask.
Notice that the pixels in the clipped raster (on the right) are not in their correct location - offset downwards.
There seems to be an offset across all of the output file.  The offset is approx 130 m.
Does anyone have any ideas as to why this happens?  It does not happen when the extent option is used instead of mask.
I am using QGIS 2.8.1 (same happens in a previous version - 2.4).  The mask layer and raster layer are in the same CRS.
Answer: Note that clipper tool (from raster menu) distort your output, or may distort it by changing cell size. My suggestion is to use the clipper under gdal tools from the toolbox.
There define <code>-tr resx, resy</code> in the additional parameters window; where both resx & resy > 0. Those stand for the input raster resolution, and forces the output to keep it. You can get the resolution from the properties>metadata of your input raster. Note that it will be written like this: 30.0, -30.0; thus modify it to be 30.0, 30.0.
The image below sum it up with an example:
Comment: Thanks for that - i ran the function but for some reason kept getting error saying invalid source however, when I clicked the option 'Keep resolution of output raster' on and left out the paramerter -tr - it worked. So thanks again for that.
Comment: I tried it with the 'keep resolution of output raster' without -tr and it didn't work; only work with -tr for me
Answer: I had the same problem. Note that I'm now using 2.18 version of QGIS where now there is "keep resolution" option. Using both "save as" or Raster>Extraction>Clipping, both give me a raster with a slight offset, where the first pixel is aligned with the mask layer.
The solution is to use the clipper under gdal tools and select both options

Crop the extent of the target dataset to the extent of the cutline
keep resolution of output raster.

That results in a subset with the pixels aligned with the original raster.

QGIS clipper problem when mask used


Patch antenna excitation

Question: How can we excite the patch antenna in different modes like TM10 and TM30? If a microstrip patch antenna resonates at TM10 mode can it resonate in other modes also like TM30?

Comment: change the location of the excitation and connect the drive line via a a top-to-bottom "antenna" wire whose location is given by the mode you need.
Answer: Yes, you can excite the higher order modes by feeding it above that mode cutoff at the proper point. However, it may not be an efficient radiator.
How well you excite the mode depends on how you feed it and where to feed it. You might want to look into some classical reference on exciting patch antennas (Balanis is a good starting point). The reason folks usually only excite the fundamental is because it typically is the most efficient radiating mode. You can kind of think of a patch as an array of radiating slots separated at $\lambda/2$. If you go higher, the separation gets further apart, and then they may not radiate in the intended direction. You may get pattern suck outs as well as surface waves.
In your picture, you show a microstrip feed, which does not have the inset slots. In theory, you need to somehow feed it at the point where the impedance is close to your transmission line impedance (nominally $Z_0 = 50 \Omega$). If you look in Balanis, you'll see how he does a theoretical calculation of where this feed point is; however, in practice, we just go up $\lambda/4$ and then tune it numerically.

Patch antenna excitation


Would Pluto keep an orbit without its moon?

Question: I haven't studied space that much, but I know that Pluto has very little gravity, but just enough to keep a human on its surface. Would Pluto keep a regular orbit around the sun without some extra support gravity, such as its moon?
Comment: I would think orbit mechanics (which this question really boils down to) is on topic on Space Exploration. Should this have really been moved?
Comment: Pluto's surface gravity is about 0.06g which is about a 100 times more than just enough to keep a human on it. Martian satellite Phobos has 0.0006g which _is_ just enough. Its other satellite Deimos has half Phobos' gravity which is low enough to escape it by jumping (or rather: by bouncing off).
Answer: The orbit of a planet does not in any way depend in its moons, mass or own gravity. The orbit is the same for a grain of dust as for a giant planet. It only depends on the mass on the Sun and the distance to the Sun. The eccentricity of the orbit is then given by the initial angular momentum of the orbiting object. This might explain it a bit better.
This was a really BIG breakthrough in physics, actually the foundation of physics, about 400 years ago. Big because it is irrefutable although it is counter-intuitive. It is really difficult to believe unless one tries to accept the actual observations and logic.
Answer: Yes, a planetoid such as Pluto will be able to orbit no matter how small its mass, so long as its angular momentum is within a range determined by its distance from the sun. In the case of Pluto and its primary moon, Charon, however, things are even more interesting.
If Charon were to magically disappear (ejection would be another story), the point on the line of Pluto's orbit at any one time would be very near the center of Pluto. There are other moons, but their gravitational tug is minimal. The orbital trace of the Pluto/Charon system, however, is not even inside Pluto.
Most planets have satellites that are very much less massive than they are, and thus the center of their systemic rotation is fairly close to the primary's center. The masses of Pluto and Charon, however, are significantly closer in size.

The Pluto–Charon system is noteworthy for being one of the Solar System's few binary systems, defined as those whose barycenter lies above the primary's surface . . . [108] This and the large size of Charon relative to Pluto has led some astronomers to call it a dwarf double planet.[109] . . . This also means that the rotation period of each is equal to the time it takes the entire system to rotate around its common center of gravity.[66]

Therefore, for practical purposes, with respect to the orbit of Pluto, it's far simpler to determine the trajectory of the Pluto/Charon barycenter -- which is completely above the surface of Pluto.

An oblique view of the Pluto–Charon system showing that Pluto orbits a point outside itself. Pluto's orbit is shown in red and Charon's orbit is shown in green.
Answer: It would is a short answer.
The long answer is it depends on how you eject the mass of the moon from Pluto's sphere of influence.
A good way to think of this is if we launch a satellite into solar orbit, it can orbit the sun in the same orbit as the Earth. Now, if we launch far to much mass from the earth then we could either move closer to, or further from the sun. This is the same way rockets propel themself.


Claim a specific failing test in Jenkins

Question: One team I am working on uses Jenkins + PHPUnit for CI.  I am looking for a good way to indicate a particular person is addressing a particular test which may be failing the build.  The Claim plugin seems great for claiming an entire failing build but I'm looking for some way to make it more granular. It would be particularly useful to make a "sticky" per-test claim so if the same test fails next build the Claimer is retained.  Can Claim do this (I thought it could, but I must be missing something if so)?  Can something else do this?
Comment: The feature you're looking for is part of the claim plugin. As soon as claiming and publishing the junit test results is activated for a project, test specific claiming is allowed. As I am not a PHP developer I cannot verify this suggestion: Have you tried to install the [xunit plugin](https://wiki.jenkins-ci.org/display/JENKINS/xUnit+Plugin)? If so, please drill down to a specific test result of a broken test and verify if you can claim the test.
Answer: This is provided by the Claim plugin, as indicated by MrsTang. However, you need to activate this per job.
In the Job configuration, under the Post-Build Action Publish Test Results you will find a check box Allow claiming of failed tests. That will allow you to claimed failed tests. We found that feature to work quite fine.
Comment: I think the feature is not provided by the JUnit plugin, but by the Claim plugin. I would suggest creating an issue in the Jenkins Jira for the Claim plugin, requesting to add the option to xUnit plugin as well.
Comment: Interesting.  I see that checkbox if I add 'Publish JUnit test result' but not under 'Publish xUnit test result' (I'm using PHP here).  Perhaps xUnit does not support this feature yet.


Entanglement measure to classify topological ordered states

Question: I know long-range entanglement is the essence of nontrivial topological ordered states. (Trivial refers to short range entangled and nontrivial refers to long range.) So, entanglement measure at large scale compared with correlation length is a tool to distinguish topological trivial and nontrivial states. One of the ways to measure entanglement is through topological entanglement entropy, $S_{top}=log D$, where $D$ is the quantum dimension. The state is topological trivial if and only if $D=1$. But it seems that this method can not be applied to distinguish nontrivial states. For example, for FQH state with filling factor $v=1/q$, $D=\sqrt{q}$, indicating that it is nontrivial. But we know that FQH ground state has $q$ fold degeneracy, all of them are nontrivial. My question is how to distinguish between long range entangled states in a quantitative way.
Answer: "How to distinguish between long range entangled states in a quantitative way?"
I know four quantitative ways to describe long-range entangled states.
1) Modular transformation (ground state topological degeneracy and non-Abelian geometric phases) for 2+1D topological orders. (This may be most general.)
2) K-matrix for all Abelian topological orders.
3) String-net (spherical fusion category) for 2+1D non-chiral topological orders
4) Patterns of zeros an $Z_n$ chiral algebra for chiral topological orders.
Comment: A stupid question. Can point (1) be used to classify long-range entangled states? If so, how? Should one find all possible inequivalent representations of the modular group?
Comment: Another stupid question. All these points depend on special features of 2+1 dimensions it seems. Besides point (3), it is not clear to me if any of them can be generalized to 3+1D. Are there any attempts for higher-dimensions?
Comment: Very good points! Yes all the points are for 2+1D. Point (1) may be the most general but less developed.
Answer: The quantum dimension is one such measure. The different ground states of a particular $1/q$ FQHE are not topologically distinct. In fact they aren't distinct from one another at all -- they simply span a space such that any linear combination of them is also a ground state. The existence of a ground state degeneracy that depends on the genus of the manifold that the state is constructed on is instead an indication of topological order.
The states which are topologically distinct (but don't differ in long-range correlations of a local order parameter, as in the Landau paradigm) are the states at different values of $q$, which do in fact have different values of $D$.
Comment: Thanks, but what about the hierarchy FQH states, where filling factor $v=\frac{p}{q}=\frac{r^2\tilde{p}}{s^2\tilde{q}}$. The quantum dimension is not related one by one with degeneracy $\tilde{q}$.


Chinese characters in an InfoPath browser form submitted to a web service appear as question marks

Question: I have a web service that submits InfoPath forms to a workflow. When I submit a form from the browser, Chinese characters entered into text boxes or rich text boxes are passed to the service as question marks. The service exposes two methods: one that takes the form as an XML string and another that takes it as an XML document. The problem occurs with both.The problem does not occur when submitting a form from the InfoPath application; nor does it occur if I use the browser to manually create and save a form to the SharePoint library. Any help would be much appreciated.
Answer: You don't provide enough detail to diagnose properly, but clearly you've got a problem where the wrong encoding is being used. Check the encoding of the browser form page; it should match the encoding expected by the receiving script. If you want to support Chinese and other characters, that encoding needs to be either one of the legacy Chinese encodings, or (much better idea) UTF-8.


Can we print Calculated field in Sharepoint List Header using JSON?

Question: I have a calculated field based on other multiple columns. I want to show the value of it in Header part. When I am using  the same in JSON, it says "Can not read property value of Null". However I do not have any null value in  the status column.
Comment: It's hard to tell what you're doing without seeing the JSON itself. One thing to keep in mind, however, is that list formatting requires the fields you want to reference to be part of the view (unlike calculated columns). So if you are referencing a column (`[$SomeField]`) and it isn't part of the view, the value will be null.
Answer: Per my knowledge, you cannot customize list header with JSON formatting. All we can do is to hide column header.


How can I find which parish a village in Poland belonged to?

Question: Someone on Facebook just helped me find immigration records for the Vannoske family which point to Rudnicze, Poland as their place of origin. How can I figure out which parish that village belonged to?
Answer: Not to confuse you further, but are you sure you have the right village? There is another place of the same name, also in Wielkopolska - it currently belongs to 'Parafia św. Andrzeja Boboli w Poznaniu' (Parish of St. Andrew Bobola in Poznań).
Anyway, I'd opt for emailing the 'suspected' parish - the priests should know the local history and are quite likely to be able to point you to where the records are stored (which in either case is most likely the Archdiocesan Archive in Poznań). For the parish in south Poznan (which used to be in Komorniki): http://www.parafiajunikowo.archpoznan.pl/kontakt/ For one likely to cover Rudnicze near Wągrowiec, try the parish in Wągrowiec http://wagrowiec.paulini.pl/?page_id=65
Comment: No, I don't know. Do you know which one this is for: http://www.szukajwarchiwach.pl/92/86/0/4/146?q=Rudnicze+XSKANro:t&wynik=1&rpp=15&page=1#tabSkany
Comment: I asked about that Seelenliste form the Polish archives because I found the family in there.
Comment: I'm pretty sure the cover of the book says Wongrowiec.
Comment: It most definitely does.
Answer: In many cases, identifying the name or extent of a parish will depend on the religious denomination and the time period. A parish may also have some civil scope (as in Louisiana).
I think in this case we can assume you mean the Roman Catholic parish, instead of the Lutheran parish, and that the time period is around 1900.
Kartenmeister has 2 entries for Rudnicze:

Biberfeld - Catholic Parish: Wongrowitz 1905
Rudnitsch - Catholic Parish: Rogasen, Kreis Obornik 1905

Wongrowitz is now Wągrowiec; Rogasen is now Rogoźno
[The Google map link for Rudnitsch is wonky, but I've found this database generally reliable for its data]


Is the hadith "Allah has chosen the Arabs above others" reliable, and how does it not contradict "no virtue for an Arab over a non-Arab"?

Question: The Reliance of the Traveller, by Ahmad ibn Naqib al-Misri, translated by Nuh Ha Mim Keller, states in the context of marriage:

m4.2 The following are not suitable matches for one another:
(1) a non-Arab man for an Arab woman (O: because of the hadith that the Prophet (Allah bless him and give him peace) said, "Allah has chosen the Arabs above others");
— Reliance Of The Traveller
; p. 523, Bottom

Arabic Text (of Hadith Only):
إن الله اصطفى العرب على غيرهم

(Here, "O:" indicates an "excerpt from the commentary of Sheikh 'Umar Barakat".)
This took me by surprise, since it seems to directly contradict another hadith:

... There is no virtue for an Arab over a non-Arab, nor for a non-Arab over an Arab ...

See What is the complete reference for Musnad Ahmed Hadith 22978, and any other occurrences?
Question: Is the hadith "Allah has chosen the Arabs above others" reliable, and how does it not contradict "no virtue for an Arab over a non-Arab"?

An anti-Islam blog quotes a SunniPath fatwa (no longer available):

The fact that Allah Most High has chosen the Arabs over other nations is affirmed in rigorously authenticated hadiths of the Prophet, may Allah bless him and give him peace; related by Bukhari and Muslim in their "Sahih" in the beginning of the chapter of merits, # 5897, on the authority of Wathilah ibn al-Asqa` who said, "I heard the Messenger of Allah, may Allah bless him and grant him peace, say, 'Verily Allah has chosen Kinanah from the son of Isma'il, and He has chosen Quraysh from among Kinanah and He has chosen Hashim from among Quraysh and He has chosen me from the Bani Hashim.'"

The latter hadith is at Jami` at-Tirmidhi 3605 and 3606, both listed as sahih.
Islam Q&A seems to say two contradictory things on the topic: "... Arabs are superior to others in terms of descent and lineage ..." and "... an Arab Muslim cannot be superior to a non-Arab Muslim just because he is an Arab ...".
Comment: Maybe there's a translation conflict. But the fact that by hadith Arab's have a certain superiority by lineage [sahih Muslim](https://sunnah.com/muslim/43/1) and espacilly islamqa holds the opinion that "Ahl as-Sunnah wa'l-Jamaa'ah are unanimously agreed that the Arabs are superior to others in terms of descent and lineage, and that regarding the Arabs as superior is in general terms, and does not apply at the individual level." as quoted in the fatwa you linked in your post.
Answer: The hadith of the farewell pilgrimage is strong and well known, it is also in agreement with the Quran:

يا أيها الناس إنا خلقناكم من ذكر وأنثى وجعلناكم شعوبا وقبائل لتعارفوا إن أكرمكم عند الله أتقاكم
O mankind, indeed We have created you from male and female and made you peoples and tribes that you may know one another. Indeed, the most noble of you in the sight of Allah is the most righteous of you.
 — Quran 49:13

On the other hand  اصطفى العرب is similar to  :

إن الله اصطفى آدم ونوحا وآل إبراهيم وآل عمران على العالمين
Indeed Allah chose Adam and Noah and the family of Abraham and the family of 'Imran over the worlds.
 — Quran 3:33

This is in terms of favor: in revealing the Quran in their tongue and raising the Prophet among them. Otherwise there are people like Abu Lahab who was from the Banu Hashim but is accursed in the Quran ... and there are praised Sahabah like Bilal from Ethiopia and Salman from Persia.

Kafa'ah (equality of status in marriage) is recognized by the schools, and it is generally not encouraged to marry outside of it, because inequality of presumed social status may lead to incompatibility and conflicts down the road.
However, a marriage outside of Kafa'ah is still possible and valid, but it requires the express consent of the woman and her family:
So in Hanafi marriages (who allow a woman to marry without the consent of the guardian): the guardian may contest the marriage when it is outside of Kafu.
Similarly, in Shafi marriages (who allow a father to marry off a virgin daughter without her consent): the father can not do so if it is outside of Kafu.

There are differences among the jurists as to what things to account for in Kafa'ah: They all only agree upon religious piety. Other factors include profession, freedom, wealth and various facets of lineage such as whether the person is arab or not.
Most of the jurists recognized some form of lineage as a valid factor, except for the Malikis:

ولم يعتبر المالكية الكفاءة في النسب
The Malikis do not account for lineage in Kafa'ah
— الفقه الإسلامي وأدلته للزحيلي

The author also preferred this view and cited several examples from the life of the Prophet where he arranged marriages outside of lineage, e.g the marriages of Zaid bin Haris and Usama bin Zaid:

والحق أن اعتبار النسب في الكفاءة ليس صحيحاً، والصحيح قول المالكية
The truth is that consideration of lineage in Kafa'ah is not correct, and the saying of the Malikis is correct.
Comment: Why do you say a Shafi follower would marry off her daughter without her consent? Isn't that prohibited in Islam making the nikah null and void?
Comment: @Ahmed It is agreed upon that the consent of the daughter should be taken, however there is difference of opinion on whether it is obligatory and whether a marriage without her consent would be invalid. Their argument is based on for example [this](https://sunnah.com/muslim/16/79) hadith, a previously married woman  has the right, which implies that a virgin does not have the right but it is mustahab to have her consent.
Comment: Jazakallah Khair for the link and the clarification.
Answer: Quranic verse says that Adam. Noah and family of Ibrahim are blessed , but no wrong doers  among them .  These hadeeths are clearly false and  make us like the Jews who have been rebuked in the Quran .
No women can be married without consent . That is harming her and is like rape .  Traditional islamists made a lot of mistakes for which all Muslims are suffering . In this regard , we are clearly forgetting the hadeeth , that we would be making  the same mistakes as Jews and Christians


What's the relation between у.е. to USD?

Question: I noticed that in Russian, when one wants to sell something in USD he writes instead  in Cyrillic letters:  у.е. for example:  120.000  у.е. What's the relation between  the letters у.е. to USD?
Comment: у.е. AKA "[Killed Racoons](http://lurkmore.to/%D0%A3%D0%B1%D0%B8%D1%82%D1%8B%D0%B5_%D0%B5%D0%BD%D0%BE%D1%82%D1%8B)"
Comment: https://ru.wikipedia.org/wiki/%D0%A3%D1%81%D0%BB%D0%BE%D0%B2%D0%BD%D0%B0%D1%8F_%D0%B5%D0%B4%D0%B8%D0%BD%D0%B8%D1%86%D0%B0
Comment: @Alexander or, as PETA insists, "Gloomy Raccoons"
Answer: У. е. means условная единица, "conventional unit".
States with significant Russian speaking population (Russia, Belarus, Ukraine, other former USSR republics) were experiencing high level of inflation and financial instability during the 90's and early 2000's, so the businesses usually kept their books of accounts and price lists in stable currencies like USD or the Deutsche Mark or later Euro, and only used the national currencies to actually convey financial transactions, at the rate in effect as of the moment of the transaction.
Listing the prices in currencies other than national, however, was illegal, so as a workaround, the prices were listed as "conventional units" and a remark was made that the conventional unit rate was the same as the USD or other stable currency rate. But the rate could really be anything, at the retailer's discretion, so it varied a lot and was used for marketing tactics.
So the у. е. is "conventional unit" which is usually one USD but can be off by several percent or something completely different altogether.
This can also be used as a metonymy for "the United States dollar"
Answer: "У.е." is for "условные единицы", "conditional unit". IIRC the term originated because by law you couldn't set prices in foreign currencies, but what you could do is set a price in some unit that is convertible to rouble in a particular fashion. So, when a shop wanted to set a price in USD, they would say that the thing costs 100 "у.е." with a disclaimer that one "у.е." means the number of roubles for one USD.
See also: Russian Wiki.


Should the choice of propensity score matching versus weighting depend on the degree of overlapping of PS distributions?

Question: I heard some opinions that matching is no good since it excludes some subjects. However, if we use PS adjustment or PS inverse probability weighting, is there a requirement on the degree of overlapping of PS distributions? Would these methods still work if the overlapping is poor?
Answer: For propensity score matching, a lack of overlap yields poor balance if matching without replacement, a small sample size and therefore poor precision if matching with replacement, and a small sample size and a change in estimand if using a caliper. For propensity score weighting for the ATT or ATE, a lack of overlap yields poor balance and a small effective sample size. Both methods "work" when overlap is poor, but they may not work well.
I would not say the choice of matching vs. weighting should depend on the degree of overlap, but the methods used to customize your primary adjustment method should. In this answer, I go into detail on several ways of customizing your weighting method to handle lack of overlap. These methods include changing the estimand, adjusting the weights once estimated, and estimating the weights without using propensity scores. There are several analogous methods for matching: you can use a caliper to restrict matches to be close to each other (which may improve balance but decrease sample size and change the estimand) and you can use tools other than the propensity score to perform the matching, like cardinality matching, which was specifically designed for matching in the presence of low overlap (but also can change the estimand).
Generally, there is a tradeoff between treatment group balance (the degree to which the covariate distributions in the treatment groups resemble each other), precision (determined by the sample size or effective sample size of the matched/weighted sample), and representativeness (the degree to which the matched/weighted sample resembles the target population). Low overlap causes you to have to manage this tradeoff and sacrifice at least one of these desired qualities. If whatever sacrifice you would make would invalidate your inference (e.g., you must estimate the ATT but the only method that gives you balance and precision sacrifices representativeness), then you have to say that your sample simply does not carry enough information to make a valid inference.
Finally, although propensity score overlap can be a good heuristic to assess the overlap of the covariate distributions, it's very possible to incorrectly estimate the propensity score, making assessments based on it invalid. For example, a highly overfit propensity score, which may predict selection into treatment very well, will likely yield many propensity scores close to 0 and 1, indicating poor overlap, regardless of whether the covariate distributions are overlapping. Rather than think about overlap, I encourage you to think about balance, the potential for balance, and the cost of balance (in terms of precision and retention of representativeness). Usually, when we say we have low overlap, we mean the cost of balance is high. This perspective allows us to consider methods that directly balance covariates and more carefully examine the tradeoffs without the heuristic of the propensity score. Many of these methods have been developed recently and have not gained mainstream exposure.
Comment: I agree that matching partly depends on the caliper we set. There is perhaps a tradeoff between balance, precision and representativeness.
Comment: The following statement is a bit confusing: a highly overfit propensity score, which may predict selection into treatment very well, will likely yield many propensity scores close to 0 and 1, indicating poor overlap, regardless of whether the covariate distributions are overlapping. Since propensity scores depend on covariate distributions, the two should be consistent? If your propensity model is correct and you get one group with propensity scores close to 1 and the other group with propensity scores close to 0, there is a problem with the data: violation of positivity assumption.
Comment: Not necessarily. If your propensity score model contains a (near) perfect instrument (i.e., causes selection into treatment but has no effect on the outcome), you will get near-perfect prediction and little overlap in the PS even if there is overlap for all other relevant covariates. Overfitting a PS model, e.g., fitting a model with close to as many parameters as there are participants, will also yield near-perfect prediction even if the covariate distributions overlap well. This is a problem of finite sample size.


how to ensure formatting in tex doc remains same once it's compiled

Question: Using \clearpage or \newpage will work sometimes or will ensure that the figure stays in the same section, but I cannot always get the heading of a subsection and the introduction to it to appear before a data table/graphic etc. Is there any particular package or formatting that should be included to ensure that the order I write it in will be the same it is compiled in?
Comment: I'm not quite sure what you want: Maybe http://tex.stackexchange.com/questions/279/how-do-i-ensure-that-figures-appear-in-the-section-theyre-associated-with?
Comment: Welcome to tex.sx! [This](http://tex.stackexchange.com/questions/11791/how-can-i-inhibit-latex-to-float-a-table-across-a-section-boundary) question might be of interest to you.
Comment: @Caramdir: I can get the tables, etc in the same section however can't ensure that If I write the section heading and maybe an intro to the table before I write the table in the tex doc that it will appear before the table in the compiled pdf. Getting them into the same section isn't the problem.
Answer: You can use the flafter package, which ensures that a floating object only appears after its definition in the code.
Answer: It sounds like you are forcing LaTeX to place floats (figures and tables) when you should be using its own float-placing algorithms.  Use an optional argument to make recommendations to that algorithm.
\begin{figure}[h] % to place "here"
% stuff ...
\end{figure}

You can also use t for "top of the next page", b for "bottom of the next page, or p for "on a separate page of floats only".  You can give preferences like [ht] for "here, but if not possible on the top of the next page."  You can use an exclamation point to make more urgent recommendations.
See also `h' float specifier changed to `ht' warning when not attempting to specify a float, in which Stefan gives a good answer describing float placement in general.
Comment: @katrijnn, putting a float immediately after a (sub)section heading effectively leaves the heading "adrift".  if you add the text of the paragraph that follows the heading before the floating object, that almost always works better.  (this is most effective if the text of the paragraph is rather short.)
Comment: Thanks for responding quickly. I have used htbp and while it moves the table or figure to a different place on the page, it does not fix the problem of getting my heading above the figure. In some cases, it pushes it to the next page or just leaves it where it is. For example: I'm using the code \subsection{Data 1:Flipped Magnetic Field} \begin{table}[htbp] and the table appears before the subsection heading. The location of this is near the end of a page.


Chrome on Ubuntu running on Virtualbox very slow

Question: I'm running Ubuntu 12.04 (64 bit) on Virtualbox 4.2 on Win 7 Host. I'm getting frequent annoying internet issues. I'm using chrome (and previously chromium) and every no and then, the chrome just stop working. It either kills the request or delays it to quite some extent. I have to click refresh sometimes to get the page open.
I have no idea why this is happening. In windows, my internet works flawless.
Answer: I just want to clarify some things quickly, I have some experience troubleshooting Chrome on virtualbox. You are using the windows version of chrome inside a windows 7 64 bit virtual machine, correct? I have also had an issue with Chrome reporting that it crashes every time I close it. There is relatively little documentation on using chrome under these circumstances, which is why I switched to firefox under my virtual machines.
You have installed guest additions i assume? Have you tried using a different browser to see if the problem is network related?
Comment: you're right. firefox does obey quiet well.
Answer: I realize this is a 3 year old question, but I think the issue itself still exists in certain scenarios.
In my case, I had this exact same issue (by the sound of if anyway), and I fixed it by disabling IPv6 inside of the VM.  After that, everything was back to normal.


Display Static block list in drop down in create product page

Question: I want to display the static block list in magento admin product creation page.
I referred this link http://www.milessebesta.com/web-design/magento-use-custom-product-attributes-to-add-cms-static-block-to-product-page/
But it shows manual entry of static block names in custom options.
I want to show the static block option list dropdown as dynamic.
Answer: You can find here and explanation of how you can add a product attribute with a custom source model.
The idea is to add a simple attribute like any others (via an install script) and fill in the field source_model with the alias of a model.
This way, when the options are retrieved, the method getAllOptions from the source model class is called. And that method can contain anything.
In your case, you just need to change in the example I linked the method getAllOptions and make it look like this:
public function getAllOptions($withEmpty = false)
{
    if (is_null($this->_options)){
        $this->_options = array();
        $collection = Mage::getModel('cms/block')->getCollection();
        foreach ($collection as $block) {
            $this->_options[] = array('label'=> $block->getTitle(), value => $block->getId());
        }
    }
    $options = $this->_options;
    if ($withEmpty) {
        array_unshift($options, array('value'=>'', 'label'=>''));
    }
    return $options;
}

Comment: @vinothavn. Yep. it should
Comment: After implementing the module, If we add a new static block, will that be displayed along with the drop down list?? @marius
Comment: Thats great. Tanq


Android Studio doesn't find CocoaPods when the package `flutter_inappwebview` is added

Question: Android Studio doesn't find CocoaPods when the package flutter_inappwebview is added to pubspec.yaml. It complains that CocoaPods is not installed.
But I can still build and run the app from the console with flutter run.
The minimal project to illustrate this bug is in https://github.com/kvutien/my_inappwebview
Any idea why?
My development configuration

Macbook Pro with M1 Pro chip and macOS 12.1 Monterey
flutter doctor output:

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 2.8.1, on macOS 12.1 21C52 darwin-arm, locale en-LU)
[✓] Android toolchain - develop for Android devices (Android SDK version 32.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 13.1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2021.1)
[✓] Connected device (2 available)

• No issues found!

How to reproduce the bug

In Android Studio, create New Flutter Project
Set the SDK used in File > Project Structure > Project > Project SDK, select Android API 32
Select an iOS virtual device
Run the app to prove that it works, from the box.
open pubspec.yaml add the following line to the section dependencies (that should be at line 29 of the template code), immediately below sdk: flutter,

  flutter_inappwebview: ^5.3.2

run pub get to update the dependencies
run the app  with the Run buttton

Android Studio will complain
Launching lib/main.dart on iPad mini (6th generation) in debug mode...
Warning: CocoaPods not installed. Skipping pod install.
  CocoaPods is used to retrieve the iOS and macOS platform side's plugin code that responds to your plugin usage on the Dart side.
  Without CocoaPods, plugins will not work on iOS or macOS.
  For more info, see https://flutter.dev/platform-plugins
To install see https://guides.cocoapods.org/using/getting-started.html#installation for instructions.

CocoaPods not installed or not in valid state.
Error launching application on iPad mini (6th generation).

Build and run still possible from Android Studio's Terminal
It's not a problem with missing CocoaPods, nor of missing PATH in configuration.
Without changing anything in the code, open the Terminal pane of Android Studio and type flutter run. The build will succeed and the app will run in the virtual device.
Launching lib/main.dart on iPad mini (6th generation) in debug mode...
Running Xcode build...
 └─Compiling, linking and signing...                      2,243ms
Xcode build done.                                            8.5s
Syncing files to device iPad mini (6th generation)...               56ms

But Android Studio behaves well, see sample flutter_inappwebviewer project in pub.dev
No need to run from the Terminal.
To prove it:

In Android Studio, create New Flutter Project
Set the SDK of the project as above
Select an iOS virtual device
Replace the initial main.dart with the sample code in pub.dev
Add the dependency in pubspec.yaml
Run pub get
Build and run the app with the Run buttton

Android Studio will not complain about CocoaPods with this code.
The project to illustrate this is in https://github.com/kvutien/test_in_app_webview
Any explanation is welcome.
Answer: Problem solved on February 11, 2022.
The Android Studio upgrade Bumblebee 2021.1.1 Patch 1a for macOS M1 made the bug disappear. Running the build from the IDE Run button doesn't produce anymore the CocoaPods missing error message.


How to speed up SSIS data load from Oracle database?

Question: I need to load the data from a Oracle server in another country by using SSIS package. I've configured Oracle drivers, environment variables and connections in SSDT already. I'm loading about 200 MB of data (one table) and it takes about 20 minutes! to load the data. The link in the remote location is 15Mbps with 86ms of Latency. Is there a way to configure the Oracle or SSIS package to speed up the load ?
Comment: Surely there is a way, but first you'll need to understand where most of that time is spent. How long does it take to run the query locally on the Oracle server? How long does it take to transfer a 200 MB file between the two sites?
Answer: You should get some significant performance improvement using the FetchSize connection string property. The Oracle documentation for the max value is here.

FetchSize - specifies the number of rows the provider will fetch at a
  time (fetch array). It must be set appropriately depending on the data
  size and the response time of the network. If the value is set too
  high, this could result in more wait time during the execution of the
  query. If the value is set too low, this could result in many more
  round trips to the database. Valid values are 1 to 429,496,296. The
  default is 100.

But mainly I would recommend upgrading to SSIS Enterprise edition and using this connector. Here is the one for SSIS 2014 but you can search for other versions easily. The performance of that connector is much improved.
Comment: A couple of years ago I was faced with a similar issue.  Developer put together SSIS to load oracle from MSSSQL.  Load was taking five hours.  I put an oracle 10046 trace on it and discovered that SSIS was fetching and inserting row-by-row (slow-by-slow).  I wrote a simple PL/SQL procedure to a simple INSERT INTO local_table (SELECT columns FROM REMOTE_TABLE@MSSQL.  The load took 4 minutes.
Comment: I've SQL 2014 Enterprise (SSIS Enterprise) already. I've downloaded a ODAC 3.0 connector - mentioned above - but as I tested ODAC 3.0 connector works twice time slower then Oracle ODBC instantclient_11_2. So Oracle ODBC drivers works faster. But still it takes 2 minutes to load 250k rows (8 columns) table from remote Oracle database. It takes 4 seconds to get the result from the Oracle database directly.
Comment: In addition I had to correct the System Enviromental Variables - "Path" and correct the path to ODAC 3.0 to work. From x64 path "c:\odac\odac64;c:\odac\odac64\bin;" to x86/32bit path "c:\odac\odac32;c:\odac\odac32\bin;" which will work properly from Visual Studio 2013.5 (which is 32 bit).
Comment: GregGalloway or someone else - could you tell me who to check and change the FetchSize connection string in SSIS ? I checked the Oracle Source properties in SSIS but there is no value like connection string there.
Comment: @TomaszWieczorkowski if you click on the connection manager and go to the Properties window there's a ConnectionString property. Add it there.


Should a CRUD table mix user tasks?

Question: Let's suppose our user has two primary tasks. Task 1 is to review all of today's apples, and task 2 is to turn the apples into applesauce.
She is used to using an Apple Review Queue to review each of her apples individually. Then, she opens up an Applesauce Conversion Queue and starts converting the apples into sauce, either one at a time or as a batch.
We are creating the future state for this user, and would like to not make her work through so many queues. (The current state system has a lot of queues, which we're hoping to replace with workflow-based modules). Our user is still likely to review all of her apples before processing them into applesauce, however.
Would it make sense for each task to have its own table or view? Or would it be more appropriate for her to see all apples in one place, some of them having a Waiting for Review status and others with a Ready for Applesauce status?
Advantages for separate views:

She can have a distinct signal of "clearing the queue" when the review task is done, which would make it easier for her to know when it's time to move on to the processing task
Any problematic apples would be segregated into their own space, so there's less risk that they'll be forgotten
She has one clear action per table row

Advantages for a combined view, mixing user tasks:

The apples are still apples, it's just their status and next task that's changing
It would be easy enough to filter by status (although a view is technically a filter)
This would allow for all outstanding apples to be seen on one screen, which could be useful if more than one user is working in the system

What's the better pattern for this?
Answer: Showing the list of what you're working on AND having a distinct workspace makes the most from an enterprise UX point of view. Esp if you need any more data to execute your decisions. A split view is very hand, especially if the list items themselves aren't full on table views and rather list items instead. Or list items with just a couple extra bits of info.

Should a CRUD table mix user tasks?


How massive does a satellite have to be in order to shift the earth's orbit around the sun?

Question: How massive does a satellite have to be in order to shift the earth's orbit around the sun? I am wondering how massive a satellite has to be in order to be able to shift the orbit of the earth by rotating around it. I heard it would be possible, but it would be a difficult task, but how massive does it have to be in order to be able to do that? Could you provide real-life example of something massive enough to do that, or perhaps fictional examples from science-fiction movies?
Comment: There isn't some magic mass above which the orbit is affected. For a small mass there is a small effect. For a large mass there is a large effect.
Comment: The center of mass of the Earth-Moon system (and everything in orbit) follows a smooth elliptical orbit around the sun.  Nothing we do within the system will change that.
Comment: The moon is an example.  But also would any satellite if you allow for small enough effect.
Answer: How much the earth will displaced by the satellite
depends not only on the mass of the satellite,
but also on its distance from the earth.
According to Wikipedia "Barycenter - Two-body problem" the shift
of the earth can be calculated by
$$ r_1 = a \cdot \frac{m_2}{m_1 + m_2} = \frac{a}{1+\frac{m_1}{m_2}}$$
where $r_1$ is the shift of the earth,
$a$  is the distance between the centers of earth and satellite,
$m_1$ and $m_2$ are the masses of the earth and satellite.
Because of the large mass of the earth ($m_1 = 6\cdot 10^{24}\ \text{kg}$)
the shift of the earth by a man-made satellite is unmeasurable small
($r_1 \approx 10^{-13}\ \text{m}$),
even if its mass $m_2$ is many tons and its distance $a$ is many thousand km.
You should insert some numbers into the formula above and do the calculation
by yourself.
Another real-life example is the moon which is also a satellite
orbiting the earth.
According to the same Wikipedia article
"Barycenter - Primary secondary examples"
the shift of the earth due to the moon is $4670\ \text{km}$.


How to use python get distance in depth image using realsense D435?

Question: Camera: realsense D435
Operating system: Ubuntu 16.04
Language: python
I want to get the distance of a point in image. If I use the aligned image that provided in github, there are many holds and the converted depth pixel to metric value will become 0, 0, 0.
What my idea is:

depth image inpainting
get depth value from depth image
using depth value to calculate distance

Following get distance example in GitHub, the code is:
depth = get_depth_at_pixel(depth_frame, pixel_x, pixel_y)
x, y, z = convert_depth_pixel_to_metric_coordinate(depth, pixel_x, pixel_y, camera_intrinsics)

I found that the output depth is float.
Now, I can get value from depth image, which is in numpy.uint16.(e.g. depth_image[200][100] is 300)

Can I convert depth image to double/float, so that I can get the distance?
If yes, How can I convert depth image to double/float value?
Answer: depth_float32 = depth.astype(np.float32)


What do we call "easily readable books"?

Question: I just wonder if there is a good expression to refer to an "easily readable book", like a simple short story or pocket book?
Comment: 'Light reading' or 'Light viewing' refers to something read or viewed without striving for a deep understanding or study of the material
Comment: When we were young, we called them "railway station books." We would buy them at the train station before long journeys here in India. (Long journeys could last anywhere between one and three days.)
Comment: I call them "easy reads." Like, _The Cat Who_ books are an easy read.
Comment: I've heard them referred to as "easy readers". Also "chapter books".
Answer: Consider a "Digest" (from Digest-sized)

Digest size is a magazine size, smaller than a conventional or
  "journal size" magazine but larger than a standard paperback book,
  approximately 5½ x 8¼ inches, but can also be 5⅜ x 8⅜ inches and 5½ x
  7½ inches. These sizes have evolved from the printing press
  operation end. Some printing presses refer to digest-size as a
  "catalog size," such as that used by Avon Products when selling house
  to house. The digest format was considered to be a convenient size for
  readers to tote around or to leave on the coffee table within easy
  reach.

The most famous digest-sized magazine is Reader's Digest, from which the size appears to have been named.
Also, consider digestible adj.

(of information) easy to understand or follow.
Answer: Abridged

verb
  (often as adjective abridged) Shorten (a book, film, speech, etc.) without losing the sense:
  an abridged text of his speech
OED

I have seen abridged versions of lots of longer books such as Sherlock Holmes books that have been abridged to make them more appropriate for a younger more modern audience.
However this probably doesn't apply to shorter books that have been written as simple books. I would call those 'light reading' or 'easy reading'.
Answer: What about pulp fiction? The term referring to fiction that was printed en mass, for consumption by a wide target audience. "Pulp" referring to the cheap paper it was printed on, to further facilitate the cost of mass-production.
And no, not the movie!
Comment: Answers should *explain*, not just *tell*, for instance by excerpting a dictionary definition or providing examples. Otherwise, I would need to downvote, as not all "easily readable books" can be classified as *pulp fiction*; the cheap self-help books, celebrity memoirs, and business guides sold in the same places wouldn't necessarily qualify, for example.
Answer: Every Book is readable in its own ways, it is whether we are worth of it or not ? Well, some books I found myself worth of were these ,
(starting from YA) Divergent Series
The Fault in our Stars
The hunger games series
Percy Jackson books are brilliant
Maze runner, of course
Alchemist (an all age book, actually)
Vampire Academy Series
The trylle trilogy by Amanda Hocking
Will Grayson, Will Grayson
The perks of being a Wallflower
The book Thief
( now the classics)
Pride and Prejudice
Moking bird
heart of darkness (to be honest, I did not read the entire book but only a short history on https://freebooksummary.com/achebe-heart-of-darkness-summary-12940
Diary of Anne Frank ( not a classic, but)
Moby Dick
The great gatsby
( The mystery)
Dan Brown books
Sydney Sheldon Books
Robert Ludlum Books
Agatha Christie
and anything else you like, these are a few, read
personally I don`t have
Answer: A novella TFD (sometimes called a novelette).

A short novel.


Do notes in a melody resolve just like chords?

Question: If I am in the key of C and I play a G major chord it is considered the dominant chord in the key of C and as a result it resolves to the C chord. But if I play a melody without any chords in C major and play a G note, does the note itself also resolve or is it only when we have chords do we talk about tension and resolution?
Comment: You could research the concept of "leading tones". Should at least partly answer your question.
Comment: @user45266 indeed.  This makes me wonder, though, about melodic resolution in the absence of leading tones (for example, a melodic line that descends to the tonic).  Is there a term for that?
Comment: @phoog I mean, maybe "voice-leading"? Although that's so context-dependent that it's hardly applicable... There probably isn't a great phrase for it.
Answer: Think of playing a broken chord stacatto style. Though the notes don't play at the same time, the brain remembers the notes it hears and builds the intervals. The same happens with a melody; the brain remembers the notes and expects certain notes; when a different note is heard, it creates tension.
Interesting discussion, by the way. It's giving me some arrangement ideas.
Comment: Trying to understand how this answers the question.
Comment: @Tim - I think this answer is trying to imply that the answer to the question is **yes**, melody notes also get involved in tension and resolution.
Answer:
...But if I play a melody without any chords in C major and play a G note, does the note itself also resolve

Whatever music set C major as the key by definition is creating tonal identities for the various tones and those tones do have melodic tendencies.
But there are some things to unpack about resolution and tendencies.
Consider both perfect and half cadences can end phrases and therefore are points of stability. By extension you can say the tonic and dominant tones are both points of stability within the key. Further, as points of stability they don't need resolution. Of course there is the hierarchy of dominant as an intermediate ending and tonic as a final ending, but both are endings of some kind.
Tendency tones are those that have a melodic tendency to step in a certain directions. Basically these are tones of the dominant resolving to the tonic chord. The leading tone moves up to the tonic, the subdominant moves down to the mediant, the supertonic moves down to the tonic. The dominant does not move as it it present in both dominant and tonic chords, which sort of reinforces the previous idea that the dominant can act as a point of stability.
This seems to set up a contradiction: the dominant chord can be stable, but its tones have a tendency (a necessity) to resolve to the tonic.
I think the way to reconcile those two ideas is to pay attention to the placement of the tones within the meter and phrase.
Consider the barline and the supertonic in this example...

...when the supertonic comes after the barline as part of a dominant chord at the end of a phrase, it is at a point of partial stability. Notice that a double bar indicates a phrase ending, and when the line continues it leaps up to the dominant. In that case the supertonic isn't acting like a tendency tone, because it is part of the phrase ending.
When we get to the final ending the supertonic precedes the barline as part of the penultimate dominant chord. In this metrical position it does act as a tendency tone and descends to the tonic.
So, melody tones do move with a sense of resolution, but it is important to understand how those tendencies work rhythmically within phrases.
Answer: Whilst G chord is the dominant of key C, it won't always resolve to C. That's where the tension/release can come in. We almost expect a G harmony to resolve to C, so when it doesn't - there's tension!
Tension/release can happen with certain notes in a series, so don't think it always needs chords or harmony, but since music is rarely just a single melody line, unaccompanied, it doesn't get experienced that often.
The same DOES NOT happen with note G. It can - and usually does - go anywhere else.
Your best bet is to look at quite a few pieces/songs in key C, find some G notes, and make 'note' of what comes next.
Answer: Yes, melodies relate to the tonic just as chords do.   And the bass line of a piece IS a melody of a kind, when it reaches the dominant it has a tension towards the tonic.  (That tension may be immediately gratified, delayed or even frustrated of course.  But it exists!)
Melodies generally (but not invariably) end on the tonic.  The previous note will very likely be part of the dominant chord.
Exceptions will be easy to find.  Not all music, with or without chords, inhabits a world of functional harmony.   But where harmonic tension IS the game, melodies have it too.
Harmony can intensify the tension of course.  Look at a dominant CHORD compared to the dominant NOTE.   In C major, that's G, B, D.    G - particularly when it's the bass note - wants to move to C.  B (the 'leading note' - wonder why it's called that? :-) wants to step up to C too.   In combination a tension arguably more than the sum of its parts.   Add an F - which has tension towards E) to make a dominant 7th chord and it's intensified even more.   But that potent F -B tritone is just the combination of two notes with individual tensions.
Comment: First, don't READ about the tritone creating tension - play some tritones, EXPERIENCE the tension!   Yes, the dominant 7th chord has intensified pull towards the tonic compared with just a plain dominant note.  See my extended answer above.
Comment: If G wants to move to C, what is it that moves to G in the C triad?
Comment: G when it ISN'T the bass note often stays where it is.
Comment: Ok but I read that the dom 7 chord has a tritone which creates tension. Isnt this tension because of the interval and not because of the individual notes in the chord want to resolve to the tonic?
Comment: @armani the tritone isn't the only source of tension in a V7 chord.  The V-I cadence developed centuries before the V7 chord did.  I'll post an answer later today if I can make the time.


Sandwich div between two other divs in separate container in IE6

Question: I'm working on a tricky design with several layers, and it requires me to layer a div between two other overlapping divs in a separate container. Here's my simplified example which works in Firefox, but not IE6 (which is of course the client's browser of choice): http://dawnup.com/sandwich
Source:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

MIDDLE

BOTTOM

TOP

Is there a trick to getting this to work in IE6? Or is this kind of overlapping impossible?
Thanks in advance
Answer: Why can't you just move the #top element so it's not within bottom?
Comment: All divs have position: absolute. I tried relative too, but I got the same result.
Comment: can't you just move top outside of bottom?
Comment: you can also try specifying an explicit `z-index` that's lower than #top for #bottom.


How to connect 2 Analog Joysticks to the Raspberry Pi Pico microcontroller?

Question: How do you connect 2 Analog Joysticks to the Raspberry Pi Pico microcontroller? I have seen many tutorials,  but all of them show only 1 joystick through the 3 ADC pins available.
Answer: You only have 3 ADC pins.  If you need more, you can either figure out how to multiplex or add external ADC chips over some digital connection.  It's a matter of figuring out what you need, what you have, and putting converters in between.
Answer: You can use a multiplexer like CD4051BE and switch inputs very fast (after 0.5ms)


What is my login and password for Area 51?

Question: I am lost!  Trying to login to Area 51.  I have no idea what my username should be or what the password should be using your Stack Exchange?
Can you tell me?
Answer: Use the same login you're using here on Meta Stack Exchange. In your case, that's a Google account, so click the "log in with Google" button on Area 51:

Having said that, I don't see an Area 51 account on your profile already... and your account here on MSE seems to be pretty new. If you think you have an existing account on Area 51, give account recovery a try. If that also doesn't help, drop us a line with all the relevant details* and we'll see what's what.

* Do you already have an Area 51 account? Did you follow any proposals? Are you trying to create a new account? Etc. etc. Just describe the overall situation as best you can.
Answer: If you want your Area 51 account to be associated with your other Stack Exchange accounts, then you should log in with the "Stack Exchange" option, and use the same username and password that you used for your other accounts at this page.

If you don't care about associating your accounts, you can create a new account by signing up with your email and a new password on this page.
Comment: Credential matching is the way to go, but not everyone has an email/password combo that we manage. Whether someone does or not is not something you'd know without employee/developer access, of course. But just FYI - "use the same credentials you use to log in here" is usually a safer bit of advice than "the same username/password" in the general case. (This post's pretty vague on details to begin with either way, though. ¯\\_(ツ)_/¯)
Comment: Fair enough, @AdamLear. I did my best to answer the question as it was asked (OP asked for help logging in "using your Stack Exchange"), but yeah, it probably would have been more useful if I provided more general advice. Your answer is much better than mine in that regard, +1.
Comment: To be clear, nothing wrong with your answer. :) I'm just adding some perspective/guidance for future reference.


Are axons capable of endocytosis?

Question: There is evidence for the uptake of toxic substances like prions from the cell bodies of neurons via endocytosis.  There is also evidence for prion deposition in white matter.  But I haven't been able to find a discussion of whether or not endocytosis is possible from axons.  Does anybody know if this is possible?
Comment: Are you asking specifically about the myelin sheathed region or are you also including the axon termini?
Answer: Short answer
In hippocampal neurons, endocytosis does occur in the axon, but only at the synapse and at varicosities.
Background
In cultured rat hippocampal neurons, Parton et al. (1992) showed that the cell body and dendritic regions are indeed capable of endyctosis. They used horse-radish peroxidase dissolved in an internalization medium. In the axon, endocytosis was only found to occur in the pre-synaptic region and in varicosities. Varicosities are points of synaptic release from the axon, outside the synapse proper.
Hence, axonal endocytosis is limited to regions where neurotransmitters are released. Presynaptic terminals often engage actively in neurotransmitter reuptake mechanisms to recycle released neurotransmitters.
Reference
- Parton et al., J Cell Biol (1992); 119(1): 123–37

Are axons capable of endocytosis?


What type of 1/0 wire for feeder in conduit

Question: I'm putting a 50' run of feeder from a main to 100A sub panel. This will be buried in sched. 40 PVC conduit. I plan to pull 1/0 Al for the hot/hot/neutral and 4 awg Al ground. Should I be using XHHW, THWN, or type USE if I plan to pull individual wires in the conduit? I see that type USE has a thicker jacket which requires a conduit upsize.
Answer: Any of them are fine.
Don't go thinking it's clever to push the conduit fill limits. Those will make for a tougher pull.  Nothing sucks more than having to call an electrician to finish your job solely for their truck full of exotic and costly pulling tools.  So doing things that makes your pull easy is always preferred.
Speaking of that, a 100A feeder only needs #1AL wire. All those wires you named are allowed 75C thermal, and the panels and terminals are rated 75C so you're all set. And #6Al ground with the #1.  Your 1/0 could be upsized to 120A in the future, so there's that.
Answer: Given the choice, XHHW is very slightly smaller diameter than THWN, and it's also slightly tougher. It is also generally more flexible.
You are planning to run schedule 40, but you generally need some schedule 80 conduit where the conduit run exits the ground and becomes "exposed to damage" unless it never does (entering a basement below ground, say) so you generally need to size the wire fill  for schedule 80, not the slightly larger hole, due to thinner walls, of schedule 40.
If you only contemplate running 100A 50 feet the wire size is more than you need, (and nets you a whopping 0.43 volts on 100A, or 0.34V on the 80A you should be planning for with a 100A breaker over using 1 AWG) for the extra expense, at but you'll need minimum 1-1/2" PVC (for three 1 AWG and one 6 AWG or for three 1/0 and one 4 AWG) if any part of the run is exposed to damage and thus needs schedule 80, even if parts of the run are schedule 40.
2" conduit for a fill percentage considerably lower would be well worth considering, as it gives an easier pull.
Two useful calculators, or pick your own. No affiliation other than I use them myself. Read the instructions to get accurate results.
https://www.calculator.net/voltage-drop-calculator.html?necmaterial=aluminum&necwiresize=9&necconduit=pvc&necpf=0.85&material=aluminum&wiresize=0.8152&resistance=1.2&resistanceunit=okm&voltage=240&phase=ac&noofconductor=1&distance=50&distanceunit=feet&amperes=80&x=90&y=5&ctype=nec
http://conduitfillcalculator.com
You could use RMC or IMC with the conduit acting as the ground conductor in 1-1/4" size for either size wires. If you don't cross a driveway that can greatly reduce your burial depth requirement (aka how deep the trench is) which is a case where you can spend money to save other money, sometimes.


Making polygon boundaries of different feature classes coincident?

Question: I have two polygon feature classes:

Cadastral layer and
another polygon layer "zones".

In both feature classes the polygon boundaries are coincident inside their feature but not between the features.
What I want to do is leave the cadastral layer boundaries fixed and snap the 'zones' layer boundaries to them as close as possible within a distance of 2 metres to remove all the small silvers.
I have tried snapping zones to cadastral with a distance of 2 metres and that worked for some boundaries but not all slivers 2m of less. Why do some boundary lines snap to each other when inside the 2m distance and some do not?
I have also tried integrate where you can rank one class over another and generally it works well for distances 1 metre or less but over 1m can even move the rank 1 class boundaries when snapping the boundaries together which is not suitable.
What tool or combination of tools can I use to snap the boundaries of the different features together when they are within 2 metres of each other and boundaries outside of 2 metres stay as they are?
The only strong rule I want to use is that the cadastral layer boundaries cannot move at all.
Answer: You might try running the densify tool first to provide more vertices for the snap. In addition you can try different snap environments. Alternately you could set up a topology and validate it giving priority to your cadastral layer. But use copies or at least do it in an edit session since a 2m tolerance might cause unwanted changes in either or both layers.


How to connect a 3 wire plug to a 2 wire outlet?

Question: Bought a vent fan that came with 3 wires, but homes here are only 2 wires (not sure which but no ground). What to do with the extra neutral wire? Should i cut it or twist it with the other two??
Comment: What is the make and model of the fan?
Comment: Are you sure there isn't a ground wire inside the junction box, even if only a hot and neutral are connected to outlets?  Is the junction box metal with the wiring fed through metal conduit or is it plastic?
Comment: There should be a hot, a neutral, and a ground.  Don't tie ground to anything but a proper ground.
Comment: the country im in dont do the ground. there is nothing of that sort here.
Answer: Disclosure: I'm not an electrician, but I know a few and do my own electrical work to be inspected by more qualified people.
Generally in the manual for such appliances they advise grounding the green wire to the electrical box you would be installing the fan in.
This doesn't really gain much of the benefit of having a ground wire available, as it most likely will not be running to a proper ground.  Regardless, in older houses where ground wiring isn't available most of the time (mine is like this) that's the best you can do.
That said, you may want to consider if possible replacing an upstream outlet near this device with a gfci outlet.  It doesn't require a ground wire, but you can set up ground fault protection for this device without it.  I've been told that is one way to get grounded (eg. 3 prong) outlets in a house with older wiring.   You would have a circuitbreaker -> gfci -> 3 prong outlet configuration.   Then the 3 prong outlet is protected by the gfci.
This might be useful reading as well:
https://www.thisoldhouse.com/ideas/replacing-two-prong-receptacles


What are these parts?

Question: It fell from the front hub/disc brake/fork area (most likely brake caliper) on my friend's bike which I'm servicing for the first time and I have no idea what they are!
Comment: Can you take a photo of the brake and hub?
Comment: Some idea of the size may help.
Comment: Brand/model of bike, forks and brakes would also help.
Comment: Ok i thought they might be common. Bike is a Specialized Pitch from the last 3-4 years. Photo on the way.
Answer: They're shims for adjusting the disc caliper lateral position, for disc brakes that don't have ISO-style mounting bolts.

Those ones fall out easily and are annoying to deal with in general, so they've been replaced by "shim washers" which are equally thin, very flat washers made specifically for the purpose. Normal washers are stamped out of sheet metal and are rarely flat and often not even either, so using them as shims will leave your caliper at a slight angle and often slightly twisted as well due to the two washers not being exactly the same. In the worst case that will make hydraulic brakes leak.
You can fake these to some extend using washers cut from aluminium cans, but you're better off using proper shim washers despite the price.

What are these parts?


Why GPT model is a higher order hidden markov model

Question: I have read the GPT-1 paper, and my understanding is that it works as follows: $U$ is input tokens, $h_0=UW_e+W_p$, $h_i=\text{transformer_block}(h_{i-1})$ and the output is a probability vector $P(u)=\text{softmax}(h_nW_e^T)$, and the hidden states are the final latent layer before softmax, so the hidden states are $h_n(U)$? I do not really understand, how to formalise this as a hidden Markov chain similar to the definition in Wikipedia?
Answer: The statement that GPT is a higher order hidden Markov model should not be taken too seriously.  It is intended as a slogan or intuition, not something that is intended to be be rigorously proven.
Let $x_1,x_2,\dots,x_k$ denote the words of the text, in order ($x_1$ is the first word, etc.).
GPT is a model for predicting the next word, given all prior words.  In other words, it estimates $p(x_i | x_1,x_2,\dots,x_{i-1})$.  Hopefully you can see how this resembles the formulation of a Markov model.
It is higher-order, because it uses all prior words to predict the next word, not just the previous few words.
Comment: Thank you. It is about my summer research, so I think is should be taken seriously. I can see the higher order Markov model structure, but I do not understand the hidden state.
Comment: @123,  I am not convinced that there is any hidden state, and I am not convinced that you should take the "hidden" part of that statement that seriously.  Without any context about where you have encountered that statement, I find it hard to say any more.