History.

The first impedance-based flow cytometry device, using the Coulter principle, was disclosed in U.S. Patent 2,656,508, issued in 1953, to Wallace H. Coulter. Mack Fulwyler was the inventor of the forerunner to today's flow cytometers - particularly the cell sorter. Fulwyler developed this in 1965 with his publication in "Science". The first fluorescence-based flow cytometry device (ICP 11) was developed in 1968 by Wolfgang Göhde from the University of Münster, filed for patent on 18 December 1968 and first commercialized in 1968/69 by German developer and manufacturer Partec through Phywe AG in Göttingen. At that time, absorption methods were still widely favored by other scientists over fluorescence methods. Soon after, flow cytometry instruments were developed, including the Cytofluorograph (1971) from Bio/Physics Systems Inc. (later: Ortho Diagnostics), the PAS 8000 (1973) from Partec, the first FACS (fluorescence-activated cell sorting) instrument from Becton Dickinson (1974), the ICP 22 (1975) from Partec/Phywe and the Epics from Coulter (1977/78). The first label-free high-frequency impedance flow cytometer based on a patented microfluidic "lab-on-chip", Ampha Z30, was introduced by Amphasys (2012).

Name of the technology.

The original name of the fluorescence-based flow cytometry technology was "pulse cytophotometry" (German: "Impulszytophotometrie"), based on the first patent application on fluorescence-based flow cytometry. At the 5th American Engineering Foundation Conference on Automated Cytology in Pensacola (Florida) in 1976 - eight years after the introduction of the first fluorescence-based flow cytometer (1968) - it was agreed to commonly use the name "flow cytometry", a term that quickly became popular.

Flow cytometers.

Modern flow cytometers are able to analyze many thousands of particles per second, in "real time" and, if configured as cell sorters, can actively separate and isolate particles with specified optical properties at similar rates. A flow cytometer is similar to a microscope, except that, instead of producing an image of the cell, flow cytometry offers high-throughput, automated quantification of specified optical parameters on a cell-by-cell basis. To analyze solid tissues, a single-cell suspension must first be prepared.  A flow cytometer has five main components: a flow cell, a measuring system, a detector, an amplification system, and a computer for analysis of the signals. The flow cell has a liquid stream (sheath fluid), which carries and aligns the cells so that they pass single file through the light beam for sensing. The measuring system commonly uses measurement of impedance (or conductivity) and optical systems - lamps (mercury, xenon); high-power water-cooled lasers (argon, krypton, dye laser); low-power air-cooled lasers (argon (488 nm), red-HeNe (633 nm), green-HeNe, HeCd (UV)); diode lasers (blue, green, red, violet) resulting in light signals. The detector and analog-to-digital conversion (ADC) system converts analog measurements of forward-scattered light (FSC) and side-scattered light (SSC) as well as dye-specific fluorescence signals into digital signals that can be processed by a computer. The amplification system can be linear or logarithmic.  The process of collecting data from samples using the flow cytometer is termed 'acquisition'. Acquisition is mediated by a computer physically connected to the flow cytometer, and the software which handles the digital interface with the cytometer. The software is capable of adjusting parameters (e.g., voltage, compensation) for the sample being tested, and also assists in displaying initial sample information while acquiring sample data to ensure that parameters are set correctly. Early flow cytometers were, in general, experimental devices, but technological advances have enabled widespread applications for use in a variety of both clinical and research purposes. Due to these developments, a considerable market for instrumentation, analysis software, as well as the reagents used in acquisition such as fluorescently labeled antibodies have been developed.  Modern instruments usually have multiple lasers and fluorescence detectors. The current record for a commercial instrument is ten lasers and 30 fluorescence detectors. Increasing the number of lasers and detectors allows for multiple antibody labeling, and can more precisely identify a target population by their phenotypic markers. Certain instruments can even take digital images of individual cells, allowing for the analysis of fluorescent signal location within or on the surface of cells.

Hardware.

Fluidics system of a flow cytometer.

Cells must pass uniformly through the center of focused laser beams to accurately measure optical properties of cells in any flow cytometer. The purpose of the fluidic system is to move the cells one by one through the lasers beam and through-out the instrument. Fluidics in a flow cytometer with cell sorting capabilities also use the stream to carry sorted cells into collection tubes or wells.

Hydrodynamic focusing.

For precise positioning of cells in a liquid jet, hydrodynamic focusing is used in most cytometers. The cells in suspension enter into the instrument enclosed by an outer sheath fluid. The sample core is maintained in the center of the sheath fluid. The sample input rate or how fast the cells flow through to the laser interrogation can be controlled by the pressure of the sheath fluid on the sample core. Under optimal conditions, the central fluid stream and sheath fluid do not mix.

Acoustic-assisted hydrodynamic focusing.

Acoustic focusing technology is used in some flow cytometers to support hydrodynamic focusing. Acoustic waves (>2 MHz) pre-focus the sample before introduction to sheath fluid. The pre-focused sample is then injected into the hydrodynamic core and flowed through the instrument. This may help with increasing data accuracy under high sample input rates.

Optics and electronics.

Optical filters.

Light emitted from fluorophores are in a spectrum of wavelengths, so combining multiple fluorophores may cause overlap. To add specificity, optical filters and dichroic mirrors are used to filter and move light to the detectors such as photomultiplier tubes (PMTs) or avalanche photodiodes (APD). Optical filters are designed as band pass (BP), long pass (LP), or short pass (SP) filters. Most flow cytometers uses dichroic mirrors and band pass filters to select specific bands of the optical spectrum.

Prisms, gratings, and spectral flow cytometry.

Spectral flow cytometry uses prisms or diffraction gratings to disperse the emitted light of a marker across a detector array. This allows for the full spectra from each particle to be measured. The measured spectra from single cells are subsequently unmixed by using reference spectra of all used dyes and the autofluorescence spectrum. This may allow for a wider panel design and the application of new biological markers.

Imaging flow cytometry.

Imaging flow cytometry (IFC) captures multichannel images of cells. Detectors used in imaging platforms can be equipped with charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) to capture images of individual cells.

Data analysis.

Compensation.

Each fluorochrome has a broad fluorescence spectrum. When more than one fluorochrome is used, the overlap between fluorochromes can occur. This situation is called spectrum overlap. This situation needs to be overcome. For example, the emission spectrum for FITC and PE is that the light emitted by the fluorescein overlaps the same wavelength as it passes through the filter used for PE. This spectral overlap is corrected by removing a portion of the FITC signal from the PE signals or vice versa. This process is called color compensation, which calculates a fluorochrome as a percentage to measure itself.  Compensation is the mathematical process by which spectral overlap of multiparameter flow cytometric data is corrected. Since fluorochromes can have wide ranging spectrum, they can overlap, causing the undesirable result of confusion during the analysis of data. This overlap, known as spillover and quantified in the spillover coefficient, is usually caused by detectors for a certain fluorochrome measuring a significant peak in wavelength from a different fluorochrome. Linear algebra is most often used to make this correction.  In general, when graphs of one or more parameters are displayed, it is to show that the other parameters do not contribute to the distribution shown. Especially when using the parameters which are more than double, this problem is more severe. Currently, no tools have been discovered to efficiently display multidimensional parameters. Compensation is very important to see the distinction between cells.

Gating.

The data generated by flow-cytometers can be plotted in a single dimension, to produce a histogram, or in two-dimensional dot plots, or even in three dimensions. The regions on these plots can be sequentially separated, based on fluorescence intensity, by creating a series of subset extractions, termed "gates." Specific gating protocols exist for diagnostic and clinical purposes, especially in relation to hematology. Individual single cells are often distinguished from cell doublets or higher aggregates by their "time-of-flight" (denoted also as a "pulse-width") through the narrowly focused laser beam  The plots are often made on logarithmic scales. Because different fluorescent dyes' emission spectra overlap, signals at the detectors have to be compensated electronically as well as computationally. Data accumulated using the flow cytometer can be analyzed using software. Once the data is collected, there is no need to stay connected to the flow cytometer and analysis is most often performed on a separate computer. This is especially necessary in core facilities where usage of these machines is in high demand.

Computational analysis.

Recent progress on automated population identification using computational methods has offered an alternative to traditional gating strategies. Automated identification systems could potentially help findings of rare and hidden populations. Representative automated methods include FLOCK in Immunology Database and Analysis Portal (ImmPort), SamSPECTRAL and flowClust in Bioconductor, and FLAME in GenePattern. T-Distributed Stochastic Neighbor Embedding (tSNE) is an algorithm designed to perform dimensionality reduction, to allow visualization of complex multi-dimensional data in a two-dimensional "map". Collaborative efforts have resulted in an open project called FlowCAP (Flow Cytometry: Critical Assessment of Population Identification Methods,) to provide an objective way to compare and evaluate the flow cytometry data clustering methods, and also to establish guidance about appropriate use and application of these methods.

FMO controls.

Fluorescence minus one (FMO) controls are important for data interpretation when building multi-color panels - in which a cell is stained with multiple fluorochromes simultaneously. FMO controls provide a measure of fluorescence spillover in a given channel and allow for compensation. To generate a FMO control, a sample is stained with all the fluorochromes except the one that is being tested - meaning if you are using 4 different fluorochromes your FMO control must contain only 3 of them (example: fluorochromes - A, B, C, D; FMOs - ABC_, AB_D, A_CD, _BCD).

Cell sorting by flow cytometry.

Cell sorting is a method to purify cell populations based on the presence or absence of specific physical characteristics. In flow cytometers with sorting capabilities, the instrument detects cells using parameters including cell size, morphology, and protein expression, and then droplet technology to sort cells and recover the subsets for post-experimental use.  The first prototype sorter was built at the Los Alamos National Laboratory (LANL) in 1965 by physicist Mack J. Fulwyler by joining a Coulter volume sensor with the newly-invented ink jet printer. Live cell cell sorter or fluorescence-activated cell sorter (FACS) was generated by Len Herzenberg, who subsequently won the Kyoto Prize in 2006 for his seminal work.  Flow cytometry cell sorters have a collection system unlike flow cytometry analyzers. The collection process starts when a sample is injected into a stream of sheath fluid that passes through the flow cell and laser intercepts. The stream then carries the cell through a vibrating nozzle. The disturbance in the stream causes it to break into a droplet containing ideally one cell. An electrical charging ring is placed just at the point where the stream breaks into droplets. A charge is placed on the ring based immediately prior to fluorescence intensity being measured, and the opposite charge is trapped on the droplet as it breaks from the stream. The charged droplets then fall through an electrostatic deflection system that diverts droplets into containers based upon their charge. In some systems, the charge is applied directly to the stream, and the droplet breaking off retains charge of the same sign as the stream. The stream is then returned to neutral after the droplet breaks off.  If collected under sterile conditions, these cells can be further cultured, manipulated, and studied.

Labels.

Flow cytometry uses the light properties scattered from cells or particles for identification or quantitative measurement of physical properties. Labels, dyes, and stains can be used for multi-parametric analysis (understand more properties about a cell). Immunophenotyping is the analysis of heterogeneous populations of cells using labeled antibodies and other fluorophore containing reagents such as dyes and stains.

Fluorescent labels.

A wide range of fluorophores can be used as labels in flow cytometry. Fluorophores, or simply "fluors", are typically attached to an antibody that recognizes a target feature on or in the cell; they may also be attached to a chemical entity with affinity for the cell membrane or another cellular structure. Each fluorophore has a characteristic peak excitation and emission wavelength, and the emission spectra often overlap. Consequently, the combination of labels which can be used depends on the wavelength of the lamp(s) or laser(s) used to excite the fluorochromes and on the detectors available. The maximum number of distinguishable fluorescent labels is thought to be 17 or 18, and this level of complexity necessitates laborious optimization to limit artifacts, as well as complex deconvolution algorithms to separate overlapping spectra. Flow cytometry uses fluorescence as a quantitative tool; the utmost sensitivity of flow cytometry is unmatched by other fluorescent detection platforms such as confocal microscopy. Absolute fluorescence sensitivity is generally lower in confocal microscopy because out-of-focus signals are rejected by the confocal optical system and because the image is built up serially from individual measurements at every location across the cell, reducing the amount of time available to collect signal.

Quantum dots.

Quantum dots are sometimes used in place of traditional fluorophores because of their narrower emission peaks.

Isotope labeling.

Mass cytometry overcomes the fluorescent labeling limit by utilizing lanthanide isotopes attached to antibodies. This method could theoretically allow the use of 40 to 60 distinguishable labels and has been demonstrated for 30 labels. Mass cytometry is fundamentally different from flow cytometry: cells are introduced into a plasma, ionized, and associated isotopes are quantified via time-of-flight mass spectrometry. Although this method permits the use of a large number of labels, it currently has lower throughput capacity than flow cytometry. It also destroys the analysed cells, precluding their recovery by sorting.

Cytometric bead array.

In addition to the ability to label and identify individual cells via fluorescent antibodies, cellular products such as cytokines, proteins, and other factors may be measured as well. Similar to ELISA sandwich assays, cytometric bead array (CBA) assays use multiple bead populations typically differentiated by size and different levels of fluorescence intensity to distinguish multiple analytes in a single assay. The amount of the analyte captured is detected via a biotinylated antibody against a secondary epitope of the protein, followed by a streptavidin-R-phycoerythrin treatment. The fluorescent intensity of R-phycoerythrin on the beads is quantified on a flow cytometer equipped with a 488 nm excitation source. Concentrations of a protein of interest in the samples can be obtained by comparing the fluorescent signals to those of a standard curve generated from a serial dilution of a known concentration of the analyte. Commonly also referred to as cytokine bead array (CBA).

Impedance flow cytometry.

Impedance-based single cell analysis systems are commonly known as Coulter counters. They represent a well-established method for counting and sizing virtually any kind of cells and particles. The label-free technology has recently been enhanced by a "lab-on-a-chip" based approach and by applying high frequency alternating current (AC) in the radio frequency range (from 100 kHz to 30 MHz) instead of a static direct current (DC) or low frequency AC field. This patented technology allows a highly accurate cell analysis and provides additional information like membrane capacitance and viability. The relatively small size and robustness allow battery powered on-site use in the field.

Applications.

The technology has applications in a number of fields, including molecular biology, pathology, immunology, virology, plant biology and marine biology. It has broad application in medicine especially in transplantation, hematology, tumor immunology and chemotherapy, prenatal diagnosis, genetics and sperm sorting for sex preselection. Flow cytometry is widely applied to detect sperm cells abnormality associated with DNA fragmentation in male fertility assays. Also, it is extensively used in research for the detection of DNA damage, caspase cleavage and apoptosis. Photoacoustic flow cytometry is used in the study of multi-drug-resistant bacteria (most commonly MRSA) to detect, differentiate, and quantify bacteria in the blood marked with dyed bacteriophages. In neuroscience, co-expression of cell surface and intracellular antigens can also be analyzed. In marine biology, the autofluorescent properties of photosynthetic plankton can be exploited by flow cytometry in order to characterise abundance and community structure. In microbiology, it can be used to screen and sort transposon mutant libraries constructed with a GFP-encoding transposon (TnMHA), or to assess viability. In protein engineering, flow cytometry is used in conjunction with yeast display and bacterial display to identify cell surface-displayed protein variants with desired properties. The main advantages of flow cytometry over histology and IHC is the possibility to precisely measure the quantities of antigens and the possibility to stain each cell with multiple antibodies-fluorophores, in current laboratories around 10 antibodies can be bound to each cell. This is much less than mass cytometer where up to 40 can be currently measured, but at a higher price and a slower pace.  Flow cytometry protocols used for research often needs validation because of the risk of antibody binding to Fc receptors.

CFSE assay.

Cell Proliferation is the major function in the immune system. Often it is required to analyse the proliferative nature of the cells in order to make some conclusions. One such assay to determine the cell proliferation is the tracking dye carboxyfluorescein diacetate succinimidyl ester (CFSE). It helps to monitor proliferative cells. This assay gives quantitative as well as qualitative data during time-series experiments. This dye binds covalently with the long-lived molecules present inside the cell. When the cells divide, the molecules divide too and, the daughter cells possess half the dye than the parent population. This decrease in the intensity can be visualized by flow cytometry. In literature, this powerful technique of flow cytometry and CFSE has been used to find the efficiency of T-cells in killing the target cells in cancer such as leukemia. In order to visualize the target cell death, both rapid and slow, scientists have used CFSE labelling with antibody staining of certain kinds of cells and fluorescently labelled microbeads. This also gave information regarding the proliferation of the target cells upon the treatment of certain cytokines.

Flow cytometry (FCM) is a technique used to detect and measure physical and chemical characteristics of a population of cells or particles.

Buněčná separace založená na principu průtokové cytometrie (flow sorting) je rychlá a efektivní metoda sloužící k separaci částic splňujících určitá kritéria z heterogenní populace. Průtokové třídění je také známo jako FACS (z anglického Fluorescence-Activated Cell Sorting). K identifikaci částic se využívá principu průtokového cytometru.


Personal life.

His father, Steve Johnson Sr. (died in his sleep 11 May 2017 aged 58), was a tennis coach at the Rancho San Clemente Tennis and Fitness Club, and his mother, Michelle, is a math professor. His older sister, Alison, is a graduate of Sonoma State University. Johnson has credited his father with his success in tennis: "He taught me pretty much everything I know. Since I can remember, it's always been me and him out there hitting balls, having a blast. It's really been amazing. I wouldn't change anything." Growing up, he idolised Pete Sampras and Andre Agassi. At USC, Johnson was coached by Peter Smith and majored in Human Performance, but left when he was three classes short of attaining his degree. Johnson hopes to complete his degree after his tennis career.  In July 2012, Johnson signed a clothing deal with Asics America and he is represented by Sam Duvall at Lagardere Unlimited. He currently trains at the USTA Player Development Center West in Carson, California. Johnson is currently working with the USTA and travels with a few other young-ish Americans, while his personal coach is Craig Boynton, who is a USTA national coach for men's tennis. The team of Dustin Taylor and Rodney Marshall also help Steve hone his skills at the development center.  Away from tennis, he is a fan of the Anaheim Ducks.  Steve Johnson married Kendall Bateman at Maravilla Gardens in Southern California on April 21, 2018. Kendall is a former Trojan volleyball player.

Junior tennis.

In his early career Steve's dad served as his coach. Stevie won four consecutive 18-under national team titles, becoming the first player in tournament history to be a member of four championship teams. Johnson contributed to a 6–1 victory over Texas in the 2005 final, a 6–1 triumph over Southern in 2006 and clinched Southern California's 4–3 win the next year over Southern. Some of Steve's junior accomplishments include being the 2008 Kalamazoo Doubles finalist and winning the 2008 Southern California Sectional Boys 18 championship in straight sets over J.T Sundling. This marked his fourth Sectionals title and near a clean sweep of all age divisions having won the 12s, 14s and 16s. He also has the distinction of being the only player to win the Triple Crown, singles and two doubles—twice. He also won nine Gold Balls. He was ranked the third-rated California senior tennis recruit (7th overall) in the country, according to TennisRecruiting.net. Lastly, he clinched the title for Southern California at the 2007 Junior Davis Cup.

High school tennis.

Johnson is a 2008 graduate of Orange High School in Orange, California and was coached by Pete Tavoularis. Johnson won CIF singles championships in 2006 and 2007 and was named the Orange County and Los Angeles Player of the Year in both seasons. He is the only Southern Section tennis champion in the school's history. Johnson also made it a priority to play in as many team matches as possible. He missed just two because of junior tennis events and did not lose a set in team competition on his way to winning his second consecutive Golden West League title. Johnson beat future Stanford Cardinal Ryan Thacher of Harvard-Westlake High to win the Southern Section Individual Tournament when both were high school sophomores in 2006. His only high school loss of 2006 was a three-set defeat in the semifinals of Ojai to eventual champion Jason Jung of West Torrance. He then defended his title by beating future UCLA Bruin Alex Brigham of Pacifica Christian High. The victories made Johnson the first back-to-back singles winner since Tom Leonard of Arcadia in 1965 and 1966. He also became the eighth player to repeat as champion and the fourth to win the title after losing the first set at love (Leonard in 1965, Barry Buss in 1982, and Phil Sheng in 1999 each won titles after losing the first set at love). Johnson was the Orange County boys tennis player of the year as a sophomore and junior at Orange, but, like so many top players do, opted to not play high school tennis his senior year.

College tennis.

Johnson chose to play college tennis for the University of Southern California. Johnson on his decision," I chose USC because I felt like I had a great relationship with Peter Smith, USC Tennis Coach, and I got along with the team really well." As a sophomore, he was selected to represent the United States in the fourth annual Master'U BNP Paribas, an intercollegiate competition in which eight countries from around the world will play for the title. As a junior he captured the 2010–11 NCAA Singles Championship, defeating Rhyne Williams in the final. In his senior season, he captured the 2011–2012 NCAA Singles Championship, defeating Kentucky's Eric Quigley in the final, overcoming a strained abdomen and shin splints and a bout of food poisoning to retain his title. As a freshman, Johnson was selected to All-Pac-10 First Team, as well as being named the Pac-10 Doubles Team of the Year with Robert Farah. He also reached the final of the Pac-10 singles championship match and he won the ITA Regionals Doubles Championship with Farah. As a sophomore, he was also selected to the All-Pac-10 First Team and was the named the Pac-10 Doubles Team of the Year with Farah once again as well as winning the ITA Southwest Regionals doubles championship with Farah. Furthermore, as a sophomore he won the ITA National Indoor championship. As a junior, he also won the 2011 Pac-10 Singles and Doubles Title with Raymond Sarmiento. In addition, he was selected as the NCAA Tournament Most Outstanding Player and to the NCAA All-Tournament Team for singles. His exploits saw Johnson named as the Intercollegiate Tennis Association Player of the Year for the 2010–11 and 2011–2012 seasons, as well as the 2010–2011 and 2011–2012 Pac-12 Men's Player of the Year. In his college career, he became a seven-time Intercollegiate Tennis Association (ITA) All-American, two-time NCAA Singles Champion, and he captured the team title for the Trojans in all four of his years there. Furthermore, he ended his college career with an unprecedented 72 match win streak. "The biggest thing that I have learned from college tennis is to play aggressive while playing within myself and to never give up because every dual match could end up being decided on your court." These exploits led to Johnson's becoming the most decorated college player of all time.

ITF Futures Circuit.

Stevie has competed in 12 Futures tournaments in his career for singles, all of them being in the United States. He has been in 3 finals, winning two of them. He lost the 2011 Sacramento Futures tournament to Daniel Kosakowski in 3 sets. However, later in 2011, Stevie won consecutive tournaments in the Claremont and Costa Mesa futures tournaments respectively beating Darian King and Artem Sitak in straight sets. Stevie has competed in various Futures tournaments since 2006 as a high schooler, and he won his first match and earned his first point the following year. Stevie has compiled an overall record of 23 wins and 10 losses on the Futures Tour as well as winning Despite a good outing in singles on the Futures Tour, Stevie is 2–6 in doubles on the Futures Tour earning a mere Stevie no longer competes on the Futures Tour as he competes mainly on the ATP Challenger Tour as well as the ATP World Tour.

ATP Challenger Tour.

Stevie has competed in 27 Challenger tournaments in his career for singles in the United States, Turkey, Canada, and France. He won his first challenger tournament in the Comerica Bank Challenger played in Aptos, California. He won it in the summer of 2012, before the 2012 U.S. Open. In the finals, he defeated Robert Farah in straight sets, 6–3, 6–3, gaining 100 points, as well as Farah is his good friend and former Trojan teammate where they played doubles together and won 2 NCAA Championships for USC. A month after his win in Aptos, Stevie competed in 2 challenger tournaments in Turkey and France. In Izmir, Turkey, Stevie reached the semifinals and won three matches to get there. In Orléans, France, Stevie reached the second round and lost to the no.2 seed David Goffin of Belgium. However, the match was tightly contested as Goffin squeezed out a win and won 7–5, 6–4. A couple of weeks later in the 2012 Tiburon Challenger, Stevie was ousted in the semifinals by Jack Sock 4–6, 6–7(4). Next, Johnson competed in the 2012 Charlottesville Challenger but fell to Rhyne Williams in the Round of 16. Johnson planned on playing in the Knoxville Challenger as well as the JSM Challenger of Champaign–Urbana to finish the year, but a shoulder injury forced him to pull out. The shoulder injury also forced him to miss the Australian Open Wild Card Playoffs. Stevie has compiled an overall record of 32 wins and 18 losses on the Challenger Tour and has earned In doubles, Stevie has had equal success on the Challenger Tour compiling an overall record of 13 wins and 8 losses including a title in Knoxville, Tennessee with Austin Krajicek in 2011. He also made it to the finals in the 2011 Tiburon challenger partnered with Sam Querrey, but they lost 6–10 in the 3rd set super tie-breaker. In 2012, Stevie reached the semifinals in Tiburon partnered with Robert Farah, as the #1 seeds. Johnson played doubles in the 2013 Maui Challenger being seeded no.2 and reached the semifinals as his partner was Alex Bogomolov, Jr. Johnson played singles and doubles in the 2013 Sarasota Open. In singles, he lost in the quarter-finals to the eventual champion, Alex Kuznetsov, 2–6, 6–3, 1–6. In doubles, he partnered with Bradley Klahn, and they won three matches to reach the finals but lost 7–6(5), 6–7(3), 9–11. Johnson played three more clay challengers before the French Open and lost in the first round in each. After a successful French Open, Johnson won his second career challenger at the Aegon Nottingham Challenge defeating Ruben Bemelmans in the finals. Winning this tournament, helped grant him a wild-card into Wimbledon. Johnson did not finish the year strong on the Challenger Tour as he went 1-5 to finish the season. In his second challenger event of the season, Johnson won the 2014 Challenger of Dallas only dropping one set throughout the tournament. He defeated fellow American Ryan Harrison along the way, and he defeated Tunisian Malek Jaziri in the finals. After the match, he stated,"I was struggling with confidence a little before the start to this year and to come out and win the tournament here makes it more special." One month later in the 2014 Irving Tennis Classic, Johnson beat three top-100 players along the way to reach the finals, where he lost to Lukáš Rosol. A win at the 2014 Open Guadeloupe Challenger Tour tournament boosted Johnson's singles ranking to a career-high 69, and gave him his fourth career challenger title. After taking a month off from competing in tournaments, Johnson's next challenger tournament was the BNP Paribas Primrose Bordeaux where he was the number two seed. He lost in the finals to number one seed Julien Benneteau. Johnson kicked off his grass court season as the number two seed in the 2014 Aegon Trophy where fell in the quarterfinals to Gilles Müller.

ATP World Tour.

2011.

Johnson started the year in Indian Wells where he lost in the first round of qualifying in three tight sets to Frank Dancevic. Shortly after his college season, Johnson received a wild card into the 2011 Farmers Classic where he lost in the first round to Gilles Müller in three sets. Johnson then competed in qualifying of the 2011 Western & Southern Open. After scoring his first win over a top 100 player in the first round, Jérémy Chardy, he lost in the following round to Édouard Roger-Vasselin. Winning the 2011 individual NCAA championships, Johnson received a wild card to the main draw of the 2011 US Open. He played his first career grand slam match against Alex Bogomolov, Jr. and lost in five tight sets where he had a two sets to love lead.  In the 2011 Western & Southern Open, Johnson reached the quarterfinals partnered with Alex Bogomolov, Jr., and along the way defeated the no. 2 doubles team of Mirnyi/Nestor subsequently gaining 180 points. At the 2011 US Open, Johnson partnered with Denis Kudla but they lost badly in straight sets to Marcelo Melo and Bruno Soares. In the 2012 Farmers Classic, Johnson partnered up with Sam Querrey, and they reached the semifinals. Next, in the 2012 Citi Open, Johnson reached the semifinals once again, partnered with Drew Courtney.

2012.

Johnson received a wild card into the 2012 SAP Open but lost in two tie-breakers to Steve Darcis. Johnson registered his first ATP win in a main draw against Donald Young in the 2012 BB&T Atlanta Open before losing to Jack Sock in the second round. Johnson received a wild card into the 2012 Farmers Classic, but lost to Igor Sijsling in straight sets. Johnson received another wild card into the 2012 Citi Open, but lost to Benjamin Becker in straight sets. Johnson reached the third round of the 2012 US Open, where he had received a wild card for winning the individual NCAA championships once again. In the first round, Johnson beat Rajeev Ram and in the second round, Johnson advanced by defeating Ernests Gulbis. In the third round, Johnson lost to 13th seeded Richard Gasquet.  In the 2012 Campbell's Hall of Fame Tennis Championships, Johnson partnered with Denis Kudla, but they lost in the first round. Competing in the 2012 BB&T Atlanta Open, Johnson partnered with fellow American Jack Sock, but they lost in a super tie-breaker in the first round. In the 2012 Farmers Classic, Johnson partnered up with Sam Querrey, and they reached the semifinals. Next, in the 2012 Citi Open, Johnson reached the semifinals once again, partnered with Drew Courtney. In the 2012 US Open, Johnson received a wild card to the main draw and partnered with Jack Sock. In the first round they defeated the no. 1 doubles team of Mirnyi/Nestor, 1–6, 7–6, 6–2. However they lost in the second round to František Čermák and Michal Mertiňák, 4–6, 5–7.

2013.

In the 2013 Australian Open, Johnson won three qualifying matches to reach the main draw. In the first round of the main draw, he took tenth seed Nicolás Almagro the distance, but lost 5–7, 7–6, 2–6, 7–6, 2–6. Next, in the 2013 SAP Open, Johnson received a wild card to the main draw. In the first round, he defeated former top-20 player Ivo Karlović, 6–7, 6–4, 7–6. In the second round, Johnson defeated Tim Smyczek, reaching his first quarterfinal. However, in the quarterfinals, Johnson lost to eventual finalist Tommy Haas, 4–6, 2–6. Overall, Johnson compiled a 5–13 record in singles. In doubles, Johnson attained a career-high ranking of no. 126.  Johnson partnered with Jack Sock in the 2013 SAP Open, but they lost to the no. 1 doubles team of Mike and Bob Bryan, 6–7, 6–7. Johnson once again partnered with Sock in the U.S. Men's Clay Court Championships, and they reached the round of 16.  Johnson went to the 2013 French Open, qualifying for the first time and made it through to the main draw before losing in the first round to Albert Montañés, who had just won Nice the previous week. Receiving a wildcard into the maindraw of Wimbledon, Johnson lost a tight first round match to fellow American Bobby Reynolds 6–1, 6–7(4), 3–6, 7–6(4), 4–6. In the 2013 Citi Open, Johnson lost in the first round to Radek Štěpánek in straight sets. In the 2013 Winston-Salem Open, Johnson won three qualifying matches to reach the main draw and have a rematch with Bobby Reynolds. In the 2013 US Open, Johnson lost in the first round to German Tobias Kamke, failing to reach the third round as he had the previous year. Johnson and fellow American Michael Russell received a wild card in doubles, but fell in the first round.

2014.

Steve kicked off the 2014 season with a bang as he reached the main draw of the 2014 Heineken Open as a lucky loser and beat former Australian Open runner up Marcos Baghdatis, and also defeated #4 seed Kevin Anderson to reach his second quarterfinal on tour. By winning the Australian Open Wildcard Playoffs a few weeks back, Johnson received a wildcard into the main draw of 2014 Australian Open. However, he lost in the first round to Frenchman Adrian Mannarino in five sets. In the 2014 Delray Beach International Tennis Championships Johnson qualified for the main draw and beat Mikhail Kukushkin, #1 seed Tommy Haas in a third-set tie-breaker, and #6 seed Feliciano López to reach his first semi-finals. After he beat Haas, Johnson said that "Tommy is an unbelievable player and this is a win I won't forget." Haas later said, "I hate to lose, but I'm happy for him. He served well and competed hard." South African Kevin Anderson got revenge on Johnson in the semi-finals as he beat him in straight sets to reach the finals. Johnson received a wildcard into the maindraw of the 2014 BNP Paribas Open, but fell to the red-hot Spaniard Roberto Bautista-Agut in straight sets, who knocked out #4 seed Tomáš Berdych in the next round. Johnson got a rematch with Agut just a couple weeks later in the 2014 Sony Open Tennis, this time falling in three sets.  In his first clay court tournament of the year, Johnson received a wild card into the U.S. Men's Clay Court Championships where he reached the second round and lost to eventual champion Fernando Verdasco. Johnson then competed in the Open de Nice Côte d'Azur where he fell in the first round to youngster Dominic Thiem. Johnson lost in three sets, while failing to convert a match point as he was trying to serve out the match at 6-5 in the second set. Johnson next competed in the 2014 French Open where he won his first ever ATP match on clay, and advanced to the second round. In his first round match against Frenchman Laurent Lokoli, Johnson came back from a two sets to love deficit, and saved two match points along the way for a dramatic five set victory. In his second round match, Johnson lost in straight sets to fellow American Jack Sock. Johnson registered his first grass court ATP win at the 2014 Gerry Weber Open when he defeated Frenchman Albano Olivetti. Johnson's second round opponent withdrew giving Johnson a walkover to the quarterfinals where he lost to the number four seed Kei Nishikori. The following week, Johnson competed in the 2014 Topshelf Open and reached the second round before falling to the number seven seed Nicolas Mahut. Johnson then competed in the 2014 Wimbledon Championships. Unfortunately, Johnson fell in the first round in four sets to twenty-seventh seed Roberto Bautista Agut. Returning to the U.S., Johnson competed in the 2014 Hall of Fame Tennis Championships where he lost in the quarterfinals to eventual champion Lleyton Hewitt. As the sixth seed in this tournament, this was Johnson's first ATP tournament where he was seeded. Johnson then kicked off his US Open Series in Atlanta where he lost in the first round to his good friend and countryman Sam Querrey.

2016: Olympic medal and first Masters 1000 quarterfinal.

Johnson reached the third round of the 2016 Australian Open as the 31st seed but lost to David Ferrer in 3 comfortable sets. Johnson lost in the 1st round of the 2016 French Open as the 33rd seed. Johnson won his first ATP Tour level title at the 2016 Aegon Open in Nottingham, UK, defeating Pablo Cuevas in the final. Johnson reached the fourth round of 2016 Wimbledon Championships being defeated by Roger Federer in straight sets. In the 2016 Western & Southern Open he defeated Federico Delbonis in the 1st round, in the 2nd round he beat Julien Benneteau and in the 3rd round he beat 7th seed Jo-Wilfried Tsonga all this set up a tie with Grigor Dimitrov in the Quarter-final, which he lost in straight sets. Johnson defeated Evgeny Donskoy in the first round of the US Open after losing the first 2 sets. His run was ended in the second round by Juan Martín del Potro in straight sets, however. Johnson would lose in the first round of the 2016 China Open to Dimitrov and in the 2016 Shanghai Masters to Andy Murray. After two more consecutive losses, he would end his season with a second-round loss in the 2016 Paris Masters to Richard Gasquet.

2017: Second career title.

Johnson began the 2017 season with a first-round loss to Dimitrov at the Brisbane International. He would dispatch John Isner to reach the semis of the Auckland Open, but lost to Jack Sock. He then lost to Stan Wawrinka in the Australian Open second round. After reaching three straight quarterfinals in his next three tournaments, Johnson lost to Roger Federer at Indian Wells and had a disappointing second-round loss at Miami to Nicolas Mahut. However, he would rebound by capturing his second career singles title (and first on clay) at the U.S. Men's Clay Court Championships in Houston, Texas, beating Sock in the semis and Thomaz Bellucci in a thrilling final, where Johnson overcame severe cramps and being down a break to win in a final-set tiebreak.

2018: Third and fourth titles.

Johnson made the semifinals in Delray Beach, where he lost to young German Peter Gojowczyk.  In Miami, Johnson made it to the third round, where he was defeated by Spaniard Pablo Carreño Busta.  Johnson won his third title in Houston on clay courts after defeating five Americans: Ernesto Escobedo, Frances Tiafoe, John Isner, Taylor Fritz, and Tennys Sandgren.  In May, he reached the final in Geneva, only to fall to Hungarian Marton Fucsovics in three sets.  In July, Johnson won the grass-court Hall of Fame championship in Newport, Rhode Island, defeating Indian Ramkumar Ramanathan in the final in three sets.  Johnson reached the final again in Winston-Salem in August, where he was defeated by young Russian Daniil Medvedev in straight sets.

2019.

Johnson reached the quarterfinals at Delray Beach in February, where he lost to Romanian Radu Albot.  In March, Johnson beat Taylor Fritz in the first round of Indian Wells, but fell to young Canadian Denis Shapovalov in the second.  At Wimbledon, Johnson beat Albert Ramos-Viñolas in the first round and young Aussie Alex de Minaur in the second, only to be defeated by Kei Nishikori in the third round in straight sets.  At the US Open, Johnson lost in the first round to Nick Kyrgios.

World Team Tennis.

Steve Johnson was selected fifth overall in the Mylan World TeamTennis Roster Draft by the Orange County Breakers. Johnson was joined by his father, who was an assistant coach on the team. Despite ultimately placing third in the Western Conference, Johnson was the No. 2 men's singles player in the league, amassing a 62–47 record for the season. He was equally successful in men's doubles, pairing with doubles specialist Treat Huey to go 64–53. In the middle of the season, Johnson helped lead the Breakers to four consecutive victories. During the season, Johnson had victories over Andy Roddick in singles and doubles, as well as doubles victories over the Bryan Brothers, and tennis legend John McEnroe. On July 20, Johnson landed himself in the no. 4 spot on the top plays of SportsCenter that evening against Alex Bogomolov, Jr. of the Texas Wild with an amazing rally that ended with Johnson slipping and sliding for a volley winner. Steve made a successful debut with the Breakers in his first season, leading him to be named the Mylan WTT Male Rookie of the Year.

Performance timelines.

Singles.

"Current through the 2020 Australian Open."

ATP career finals.

Singles: 6 (4 titles, 2 runner-up).

!Result!class="unsortable"|W–L!Date!Tournament!Tier!Surface!Opponent!class="unsortable"|Score

Steve "Stevie" Johnson Jr. (born December 24, 1989) is an American professional tennis player. For one week in August 2016 he was the top-ranked American in men's singles. He has a career-high ranking of world No. 21. He has won four ATP Challenger Tour titles and four ATP Tour 250 titles, one at Nottingham on grass, twice at Houston on clay and most recently at Newport on grass. He won a bronze medal in men's doubles at the 2016 Olympics with Jack Sock.

Steve Johnson (* 24. prosince 1989 Orange, Orange County, Kalifornie) je americký profesionální tenista a bronzový medailista v mužské čtyřhře z Letní olympiády 2016 v Riu de Janeiru. Ve své dosavadní kariéře vyhrál na okruhu ATP World Tour čtyři turnaje ve dvouhře, včetně dvou houstonských trofejí na U.S. Men's Clay Court Championships 2017 a 2018. K nim přidal jeden deblový titul, když s krajanem Samem Querreyem triumfovali na Geneva Open 2016. Na challengerech ATP a okruhu Futures získal šest trofejí ve dvouhře a dva ve čtyřhře.


German post-WW2 division until 1990.

After German organisations had been dissolved by the Allies in 1947, in 1950 the IOC recognized the reorganized Nationales Olympisches Komitee für Deutschland for all of Germany, based in (West) Germany.  Due to the Cold War, an East German state (German Democratic Republic) was created in October 1949, and a separate National Olympic Committee (NOC) for East Germany was established in 1951. It was not immediately recognized by the IOC, which until 1965 required that athletes of the NOC of East Germany join the German team represented by the West Germany-based NOC of Germany. This team, which competed together from 1956 to 1964, is nowadays called the United Team of Germany ("EUA", "Equipe Unifiée Allemande"), but was Germany ("GER") then. As a result of the Germany being divided, from 1968 to 1990 two independent teams competed in each of the Games; the original designations were "GER" for the Federal Republic of Germany (West Germany) and "GDR" for the German Democratic Republic (East Germany). In 1980 the West German code was changed to "FRG" (which is currently also applied by the IOC in retrospect). After the GDR ceased to exist in 1990 and its states joined the Federal Republic of Germany, Germany once again was represented by a single team, designated "GER".  Additionally, in the early 1950s the French-occupied Saar had its own NOC and competed at the 1952 Summer Olympics before joining the German Olympic team in 1956 and the (West) German state by 1957.

Participation.

Combined medals.

Germany has competed at the Olympics under five different designations, including as two separate teams at several Games. Sources vary in how they present the medals won by these teams. The table below shows sourced combinations of these teams, when applied to the main table. Saar competed independently in the Summer Olympic games in 1952, but failed to win any medals. Due to most lists only listing medal counts, it's possible but not certain Saar was included as part of Germany in their calculations.

Hosted Games.

For the 1972 Summer Olympics in Munich, West Germany, see West Germany at the Olympics.

Medal tables.

Medals by summer sport.

<nowiki>*</nowiki>"This table does not include two medals – one gold and one silver – awarded in the figure skating events at the 1908 Summer Olympics."

Medals by winter sport.

<nowiki>*</nowiki>"This table includes two medals – one gold and one silver – awarded in the figure skating events at the 1908 Summer Olympics."

Athletes from Germany have taken part in most of the Olympic Games since the first modern Games in 1896. Germany has hosted three Olympic Games, in 1936 both the Winter and Summer Games, and the 1972 Summer Olympics. In addition, Germany had been selected to host the 1916 Summer Olympics as well as the 1940 Winter Olympics, both of which had to be cancelled due to World Wars. After these wars, Germans were banned from participating in 1920, 1924 and 1948. While the country was divided, each of the two German states boycotted the Summer Games: in 1980 West Germany was one of 66 nations which did not go to Moscow in protest at the Soviet invasion of Afghanistan and in 1984 East Germany joined the Soviet Union (and several others) in the boycott of the Summer Games in Los Angeles.

Německo na letních olympijských hrách startuje od roku 1896. Toto je přehled účastí, medailového zisku a vlajkonošů na dané sportovní události.


History.

Badoo was founded by Russian entrepreneur Andrey Andreev and launched in Moscow in November 2006. It has since ranked among the most popular dating websites. In 2016 it was the most-downloaded dating app in 21 countries. In 2011, "Wired" described Badoo as a "mass phenomenon" in Brazil, Mexico, France, Spain, and Italy.  In 2007, Badoo raised $30 million in funding. In January 2008, the Russian investor Finam Capital paid $30 million for a 10% stake in Badoo for expansion in Russia. As of 2009, Finam now has 20% ownership of Badoo.  After going viral on Facebook through popular social games and quizzes, Badoo was asked to adjust its approach. According to Insidefacebook.com, during the week of January 11, 2012, Badoo was ranked 17th in growing Facebook apps. The official launch of Badoo in the U.S. was on March 23, 2012, with Nick Cannon introducing the service in the United States.  In April 2017, Badoo launched a newly redesigned app and brand, adopting the colour purple and an orange heart symbol as its logo, as well as the tagline "Bigger than Dating". Andreev discussed this redesign in an interview with "Business Insider" James Cook in the same month.

Features.

Badoo has several features that enable users to meet people. When they first sign up, individuals select whether they want to meet new people to date, chat or to make new friends. Users can chat, match with others, upload photos and videos, as well as share their interests and see any friends in common.  The main features include: Badoo has developed numerous safety features to ensure users are real and verified. Such features include the'selfie request' button, through which women can request a man they're speaking to send a'selfie' to prove they are the same person as in the pictures.  The company has also developed a photo verification process, where users upload a photo of themselves mimicking a specific pose. This photo is then verified in a minute by one of Badoo's 5,000 moderators.  Badoo is a freemium service, where the basic service is free for everyone but users have an option to pay for premium features. Such features include, ‘Rise Up’, which allows users to pay to give their profile more visibility on the site for a limited time. In late 2007, 20% of Badoo's then 22 million users were paying for heightened visibility at least once a month. However, according to "The Economist", by 2011 only 5% of members were paying for the premium services.  Users can also pay to have their profile photo more widely visible across the site. "Super Powers" enables users to see more search results, as well as who wants to meet them and which of their messages have been read.

Criticisms.

In a peer-reviewed study by Cambridge University in 2009, it was given the lowest score for privacy among the 45 social networking sites examined. In the same report, it was given a ‘perfect score’ for verified accessibility on mobile devices.  Finnish newspaper "Iltalehti" reported that numerous Badoo profiles were created without people's consent, and that people have reported Badoo's actions to the police.  According to Google's transparency report on the requests for search removals stemming from the "right to be forgotten" ruling, Badoo had the eighth-highest number of URLs removed from Google Search, with Facebook, YouTube, Google Groups and Twitter receiving a higher number of these requests.  A CNET review by Rafe Needleman described Badoo's first impression as "creepy". He said that though the site was advertised as a way to meet local friends with shared interests, it was more like a photo-based dating site. He also said the way it matches users was "obscure".

Badoo is a dating-focused social network founded by Russian entrepreneur Andrey Andreev in 2006. It is headquartered in Limassol, Cyprus and London, United Kingdom, with offices in Malta, Russia and the United States. It operates in 190 countries and is available in 47 different languages, making it the world's most widely used dating network. The app is available on iOS, Android, and the web. Badoo operates on a freemium model, whereby the core services can be used without payment.

Badoo je komunitní web, zaměřující se na seznámení mezi uživateli. Web je lokalizován do 40 jazyků včetně češtiny. Badoo používají uživatelé především k získání prvního kontaktu v rámci seznámení. Je dostupný také pro mobilní zařízení. V rámci svých služeb nabízí placené seznamovací hry, vyhledávání uživatelů dle zadaných parametrů a lokality nebo omezený interní komunikační systém. Služba je založena na obchodním modelu freemium, tedy registrace a využívání základních služeb je ve velmi omezené míře bezplatné.


History.

The Web-based storefront.

Microsoft previously maintained a similar digital distribution system for software known as Windows Marketplace, which allowed customers to purchase software online. The marketplace tracked product keys and licenses, allowing users to retrieve their purchases when switching computers. Windows Marketplace was discontinued in November 2008. At this point, Microsoft opened a Web-based storefront called "Microsoft Store".

Windows 8.

Microsoft first announced Windows Store, a digital distribution service for Windows at its presentation during the Build developer conference on September 13, 2011. Further details announced during the conference revealed that the store would be able to hold listings for both certified traditional Windows apps, as well as what were called "Metro-style apps" at the time: tightly-sandboxed software based on Microsoft design guidelines that are constantly monitored for quality and compliance. For consumers, Windows Store is intended to be the only way to obtain Metro-style apps. While announced alongside the "Developer Preview" release of Windows 8, Windows Store itself did not become available until the "Consumer Preview", released in February 2012.  Updates to apps published on the Store after July 1, 2019 will not be available to Windows 8 RTM users. Per Microsoft lifecycle policies, Windows 8 had been unsupported since 2016.

Windows 8.1.

An updated version of Windows Store was introduced in Windows 8.1. Its home page was remodeled to display apps in focused categories (such as popular, recommended, top free and paid, and special offers) with expanded details, while the ability for apps to automatically update was also added. Windows 8.1 Update also introduced other notable presentation changes, including increasing the top app lists to return 1000 apps instead of 100 apps, a 'picks for you' section, and changing the default sorting for reviews to be by'most popular'.  Updates to apps published on the Store after July 1, 2023 will not be available to Windows 8.1.

Windows 10.

Windows 10 was released with an updated version of the Windows Store which merged Microsoft's other distribution platforms (Windows Marketplace, Windows Phone Store, Xbox Video and Xbox Music) into a unified store front for Windows 10 on all platforms, offering apps, games, music, film, TV series, themes, and ebooks. In September 2017, Microsoft began to re-brand Windows Store as Microsoft Store, with a new icon carrying the Microsoft logo. Xbox Store was merged into this new version of the platform. This is in line with Microsoft's platform convergence strategy on all Windows 10-based operating systems.  Web apps and traditional desktop software can be packaged for distribution on Windows Store. Desktop software distributed through Windows Store are packaged using the App-V system to allow sandboxing.  In February 2018, Microsoft announced that Progressive Web Apps would begin to be available in the Microsoft Store, and Microsoft would automatically add selected quality progressive web apps through the Bing crawler or allow developers to submit Progressive Web Apps to the Microsoft Store.

Windows Server.

Windows Store is available in Windows Server 2012 but is not installed by default. It is unavailable in Windows Server 2016. However, UWP apps can be acquired from Microsoft Store for Business (formerly Windows Store for Business) and installed through sideloading.

Details.

Microsoft Store is the primary means of distributing Windows Store apps to users. Although sideloading apps from outside the store is supported, out-of-box sideloading support on Windows 8 is only available on the Enterprise edition of Windows 8 running on computers that have joined a Windows domain. Sideloading on Windows RT and Windows 8 Pro, and on Windows 8 Enterprise computers without a domain affiliation, requires purchase of additional licenses through volume licensing. Windows 10 removes this requirement, allowing users to freely enable or disable sideloading.  Initially, Microsoft took a 30% cut of app sales until it reached US$25,000 in revenue, after which the cut dropped to 20%. On January 1, 2015, the reduction in cut at $25,000 was removed, and Microsoft takes a 30% cut of all app purchases, regardless of overall sales. Third-party transactions are also allowed, of which Microsoft does not take a cut. In early 2019, Microsoft lets app developers get 95% of app revenues, while Microsoft will only take 5% but only if user will download the app through a direct URL. Individual developers are able to register for US$19 and companies for US$99.  In 2015 over 669,000 apps were available on the store, including apps for Windows NT, Windows Phone, and UWP apps, which work on both platforms. Categories containing the largest number of apps are "Games", "Entertainment", "Books and Reference", and "Education". The majority of the app developers have one app. Both free and paid apps can be distributed through Microsoft Store, with paid apps ranging in cost from US$0.99 to $999.99. Developers from 120 countries can submit apps to Microsoft Store. Apps may support any of 109 languages, as long as they support one of 12 app certification languages.  On April 2, 2019, Microsoft announced that the sale of e-books on Microsoft Store had ceased. Due to DRM licenses that will not be renewed, all books will become inaccessible by July 2019, and Microsoft will automatically refund all users that had purchased books via the service.

Guidelines.

Similar to Windows Phone Store, Microsoft Store is regulated by Microsoft. Applicants must obtain Microsoft's approval before their app becomes available on the store. These apps may not contain, support or approve, gratuitous profanity, obscenity, pornography, discrimination, defamation, or politically offensive content. They may also not contain contents that are forbidden by or offensive to the jurisdiction, religion or norms of the target market. They may also not encourage, facilitate or glamorize violence, drugs, tobacco, alcohol and weapons.  The following types of app are forbidden:  Microsoft has indicated that it can remotely disable or remove apps from end-user systems for security or legal reasons; in the case of paid apps, refunds may be issued when this is done.  Microsoft initially banned PEGI "18"-rated content from the store in Europe. However, critics noted that this made the content policies stricter than intended, as some PEGI 18-rated games are rated "Mature" on the U.S. ESRB system, which is the next lowest before its highest rating, "Adults Only". The guidelines were amended in December 2012 to remove the discrepancy.

Developer portal.

In addition to the user facing Microsoft Store client, the store also has a developer portal with which developers can interact. The Windows developer portal has the following sections for each app:

Developer tools.

Microsoft Store provides developer tools for tracking apps in the store. One can track downloads, financials, crashes, adoption and ratings.  The dashboard also presents a detailed breakdown on users by market, age, and region, as well as charts on number of downloads, purchases, and average time spent in an app. The dashboard also allows a developer to claim an app name for up to one year before the name is returned to the available pool.

Microsoft Store (formerly known as Windows Store) is a digital distribution platform owned by Microsoft. It started as an app store for Windows 8 and Windows Server 2012 as the primary means of distributing Universal Windows Platform (UWP) apps. With Windows 10, Microsoft merged its other distribution platforms (Windows Marketplace, Windows Phone Store, Xbox Music, Xbox Video, Xbox Store, and a web storefront also known as "Microsoft Store") into Microsoft Store, making it a unified distribution point for apps, console games, digital music, and digital videos. E-books were included until 2019. Some content is available free of charge from the store.

Microsoft Store (dříve "Windows Store") je v informatice digitální distribuční platforma pro aplikace v systémech Microsoft Windows. Je primárním distribučním a prodejním kanálem pro Windows aplikace (resp. "moderní aplikace" nebo "metro aplikace"). Kromě aplikací obsahuje i digitální video, muziku a e-knihy. Je obdobou Mac App Store a obchodu Google Play. Obsažené aplikace musí být schváleny ohledně obsahu i kompatibility, což zvyšuje pro uživatele bezpečnost.


History.

The village is built in a natural karst amphitheater along the Neretva river during the Middle Ages. The earliest mention of or recorded reference to Počitelj is in charters of king Alfonso V and Fridrich III from 1444 to 1448. However, the village most likely predate these documents. The exact date can't be pinpointed but it is likely that fortified town along with its complementary settlements was built by Bosnian king Tvrtko I sometime in 1383. Počitelj was considered the administrative center and center of governance of "Župa Dubrava" (county), while its westernmost point gave it major strategic importance. During the years following Ottoman conquest of Bosnian realm, between 1464 and 1471, the town was fortified by Vladislav Herzegović with a support of Dubrovnik, king Matthias Corvinus of Hungary and the Pope. From this point the walled town of Počitelj evolved in the period from the 16th to the 18th centuries. Architecturally, the stone-constructed parts of the town are a fortified complex, in which two stages of evolution are evident: medieval, and Ottoman.  In the period between 1463–1471 the town housed a Hungarian garrison and was fortified into a strategic defence stronghold. In 1471, following a brief siege, the town was conquered by the Ottomans. It lost its strategic significance. It remained within the Ottoman Empire until 1878. From 1782 to 1879 Počitelj was the seat of a"kadiluk" (area under the jurisdiction of a qadi, or judge) and the center of the Počitelj military district from 1713 to 1835.  The significance and the town's appearance has altered during the course of its history. As far as the development of Počitelj goes, three significant periods can be distinguished:  After the establishment of Austro-Hungarian rule in Bosnia and Herzegovina in 1878, Počitelj lost its strategic importance and started deteriorating rapidly. The population declined gradually. The loss of the town's strategic role assisted in the preservation of the original urban architectural ensemble, so that the town remained in its original form to present day.  The entire historic urban site of Počitelj and surrounding area suffered extensive collateral damage during the 1992–1995 war in Bosnia and Herzegovina. Namely, it was heavily damaged by Croatian forces during the 1993 Bosnian War. Following the bombing, Počitelj's sixteenth-century master works of Islamic art and architecture were destroyed and a large part of the town's population was displaced.  As proposed by the University of York, United Kingdom, and the University of Sarajevo, Počitelj was in 1996 named by the World Monuments Watch as one of the world's 100 most endangered cultural heritage sites. In the year 2000 the Federation of Bosnia and Herzegovina Government initiated the Programme of the permanent protection of Počitelj. The programme includes the protection of cultural heritage from deterioration, restoration of damaged and destroyed buildings, encouraging the return of the refugees and displaced persons to their homes and the long-term protection and revitalization of the Počitelj's historic urban area. The Programme is on-going.  As of 2008, the International Council on Monuments and Sites (ICOMOS) expressed concern over the proposed construction of a nearby highway, Corridor Vc. Initial plans include a 1,000-meter long, 100-meter high bridge over the Neretva river. It is feared that the construction will result in a “physical, visual and ecological degradation and devastation of this cultural and historical unity and its authentic surroundings.” While a new potential location for the bridge crossing is being investigated, non-controversial sections are under construction.

Demographics.

No up-to-date data currently exists for Počitelj and its demographic profile was significantly altered after the Bosnian war. The last demographics research was conducted in 1991 and its results were as follows:  Population Total: 905

Significance.

Počitelj represents one of the few urban ensembles in Bosnia and Herzegovina that were preserved in their integrity to the present times. It was also developed through the several phases of the history beginning with the medieval period. Its significant strategic role from the 13th to 17th century gave its inhabitants the power to build one of the most important, and best preserved ensembles within the city walls in the region. The town can be compared with some of the noted world heritage sites as the old towns of Mostar (Bosnia and Herzegovina), Ohrid (North Macedonia), Safranbolu (Turkey), Gjirokaster (Albania). Počitelj's layout and use of building materials put it into the group of Ottoman-Mediterranean types of small settlements.

Počitelj is historic village and an open-air museum in Bosnia and Herzegovina. It is located in the municipality of Čapljina, in the Herzegovina-Neretva Canton of the Federation of Bosnia and Herzegovina. The historic village is situated on the left bank of the river Neretva, on the main road Mostar-Metković, and it is about to the south of Mostar and about from center of Čapljina.

Počitelj je historické město na území státu Bosna a Hercegovina, okres Čapljina, Hercegovsko-neretvanský kanton. Podél města protéká řeka Neretva, město leží na jejím levém břehu.


Early life.

Luitpold was born in Würzburg, the third son of King Ludwig I of Bavaria and his wife, Therese of Saxe-Hildburghausen. He was the younger brother of King Maximilian II of Bavaria and of King Otto of Greece. Luitpold was in line to succeed to the throne of the Kingdom of Bavaria, and was also heir presumptive to the throne of Greece, since his brother Otto had no children. However, the Greek constitution required that Otto's heir should belong to the Greek Orthodox Church. Otto was deposed in 1862 and replaced by Prince William of Denmark, who became George I, King of the Hellenes. Otto died in 1867, leaving Luitpold and his descendants as representatives of Otto's claim. However, Luitpold never pursued that claim.  At the age of fourteen, Luitpold joined the Bavarian Army and was promoted to Captain of the Artillery in 1835. During the revolutions of 1848, Prince Luitpold mediated and facilitated an audience of discontented citizens with his father. During the rule of his brother Maximilian II (1848–64), Luitpold did not play a significant political role.  With the reign of his nephew Ludwig II (1864–1886), Prince Luitpold had increasingly to represent the royal house due to the king's long absence from the capital. In the Austro-Prussian War in 1866 Luitpold was commander of the 3rd Royal Bavarian Division. In 1869, he became Inspector General of the Bavarian Army, during the Franco-Prussian War in 1870 and 1871, he represented Bavaria in the German General Staff. In that capacity, he handed over Ludwig's "Kaiserbrief" on 3 December 1870, in which Ludwig endorsed the creation of the German Empire with the King of Prussia as Emperor.  Since Ludwig, who nonetheless regretted Bavaria's loss of independence, refused to attend Wilhelm's 10 January proclamation as Emperor in the Palace of Versailles, Ludwig's brother, Prince Otto, and his uncle Luitpold represented him in the Palace of Versailles. Otto then criticized the celebration as ostentatious and heartless in a letter to his brother. In 1876, Luitpold was appointed Field Marshal.

Regency.

On 10 June 1886, Luitpold's nephew King Ludwig II was declared mentally incompetent and Luitpold was named Regent. Luitpold's part is still controversial. Following Ludwig II's mysterious death a few days later, his brother Otto assumed the throne. However, Otto was likewise (or more so) mentally incapable of reigning; he had been under medical supervision since 1883. Accordingly, Luitpold continued to serve as regent. Prince Luitpold was even accused by some people of the murder of his nephew, but soon the decent and affable prince became one of Bavaria's most popular rulers. One of his first actions (on 1 August 1886) was to open several of the palaces of Ludwig II to the public.  Politically, Luitpold remained largely passive. His governments gradually moved away from the previous anti-Catholic "Kulturkampf" policies. This development culminated in 1912 when the appointment of the Centre Party politician Georg von Hertling as minister president; this also effectively brought about a parliamentarisation of the government, as Hertling's Centre Party was the largest group in the Landtag.  During the regency of Prince-Regent Luitpold relations between Bavarians and Prussians remained cold as Bavarians resented Prussia's strategic dominance over the empire.  Luitpold continued to serve as regent until 1912, when he contracted bronchitis and died in Munich. He is buried in the crypt of the Theatinerkirche in Munich. He was succeeded by his eldest son, Prince Ludwig, who remained as regent for another year. In 1913, the constitution was amended to add a clause stating that if a regency for reasons of incapacity had lasted for at least 10 years with no prospect of the king being able to actively reign, the regent could assume the throne in his own right. Soon after this amendment was promulgated, Ludwig deposed Otto and assumed the throne as Ludwig III.  The "Prinzregentenzeit" ("prince's regent's time"), as the regency of Luitpold is often called, was due to the political passiveness of Luitpold during an era of the gradual transfer of Bavarian interests behind those of the German empire. In connection with the unhappy end of the preceding rule of King Ludwig II, this break in the Bavarian monarchy looked even stronger. Finally, the constitutional amendment of 1913 brought the determining break in the continuity of the king's rule in the opinion of historians, particularly as this change had been granted by the Landtag as a House of Representatives and meant therefore indirectly the first step toward parliamentary rule in Bavaria. Today the connection of these two developments is regarded as a main cause for the unspectacular end of the Bavarian kingdom without opposition in the course of the November revolution of 1918. However the course of his 26-year regency Luitpold grew to overcome, by modesty, ability and popularity, the initial uneasiness of his subjects. These prince's regent's years were transfigured, finally – above all in the retrospect – to a golden age of Bavaria, even if one mourned the "fairy tale king" Ludwig II furthermore what happens in a folkloric-nostalgic manner till this day.

Legacy.

Tutored as a child by Domenico Quaglio the Younger, Luitpold had a great feeling for the arts. Luitpold's years as regent were marked by tremendous artistic and cultural activity in Bavaria where they are known as the "Prinzregentenjahre" ("The Prince Regent Years") or the "Prinzregentenzeit". Bavaria prospered under a liberal government and Munich became a cultural centre of Europe. Thomas Mann wrote about this period "Munich shone" (1902 "Gladius Dei"). Schwabing became an important artists' quarter in Munich.  There are numerous streets in Bavarian cities and towns called "Prinzregentenstrasse" or "Luitpoldstrasse". Many institutions are named in Luitpold's honour including the "Prinzregententheater" in Munich and the Luitpoldarena and the Luitpoldhalle in Nürnberg. In 1891 Luitpold established the Luitpold Gymnasium in Munich. "Prinzregententorte" is a multi-layered cake with chocolate butter cream named in his honour. The vessel SMS Prinzregent Luitpold of the Imperial German Navy and the Luitpold Coast were named for Luitpold.  Luitpold's great passion next to the arts was hunting, and his legendary hunts took place throughout Bavaria.

Family.

On 1 April 1844, in Florence, Luitpold married Archduchess Auguste Ferdinande of Austria, Princess of Tuscany, second daughter of Leopold II, Grand Duke of Tuscany. Luitpold and Auguste had four children:

Luitpold Karl Joseph Wilhelm Ludwig, Prince Regent of Bavaria (12 March 1821 – 12 December 1912), was the "de facto" ruler of Bavaria from 1886 to 1912, due to the incapacity of his nephews, King Ludwig II for three days and King Otto for 26 years.

Luitpold Bavorský (12. březen 1821 Würzburg – 12. prosinec 1912 Mnichov, celým jménem "Luitpold Karl Joseph Wilhelm Ludwig") byl v letech 1886 až 1912 bavorským regentem za své synovce Ludvíka II. a Otu, kteří byli neschopní vykonávat pozici králů vzhledem ke svému duševnímu stavu. Princ Luitpold, který pocházel z bavorské dynastie Wittelsbachů byl také po svých synovcích dalším v následnictví trůnu, svého nástupu na trůn se nedožil, ale jeho syn Ludvík se stal bavorským králem rok po jeho smrti v roce 1913.


Club career.

Martínez was born in Mar Del Plata.  After injuries to Ryan Clarke and Wayne Brown, and the termination of Connor Ripley's loan, Martínez went on emergency loan to Oxford United where he made his début in the English Football League in their final game of the season against Port Vale in League Two on 5 May 2012; Port Vale won 3–0.  Martinez has been named on the Arsenal substitute bench for their fixtures away at Stoke City on 26 August 2012 and against Liverpool on 2 September 2012 as Wojciech Szczęsny and Łukasz Fabiański were injured at the time and at Southampton on 1 January 2013. On 26 September 2012, he made his Arsenal début in a 3rd Round League Cup tie at home to Coventry City. He then made his second Arsenal appearance in the following round in a 7–5 win away at Reading in which Arsenal were 4–0 down.  On 15 October 2013, Martínez transferred to Championship side Sheffield Wednesday on an emergency 28-day loan agreement. On 14 November 2013 Arsenal announced that the loan agreement had been extended until 1 January 2014. Martínez made his debut for Wednesday on 23 November 2013 against Yorkshire rivals Huddersfield Town. The loan was extended to the end of the season soon after.  Martínez was an unused substitute as Arsenal won the Community Shield on 10 August 2014, with a 3–0 win over Manchester City at Wembley Stadium. He made his Arsenal debut in the Champions League group stage match against Anderlecht, which ended in a 2–1 win to Arsenal. He then made his Premier League debut as a 2nd half substitute, replacing the injured Szczęsny against Manchester United at the Emirates Stadium.  Because of the injuries of Szczęsny and David Ospina, Martínez was made starting keeper against Borussia Dortmund on 26 November at the Emirates, keeping a clean sheet as Arsenal won 2–0. His "faultless" performance in the match led to him being named in that week's UEFA team of the week. He made his first Premier League start on 29 November against West Brom, which was followed by his second Premier League start against Southampton just four days later. He kept two clean sheets as Arsenal won both matches 1–0.  On 20 March 2015, Martínez joined Championship club Rotherham United on an emergency loan until the end of the season. He made his debut the following day against South Yorkshire rivals Sheffield Wednesday, conceding two added-time goals in a 3–2 home defeat.  On 2 August 2015, Martínez was an unused substitute as new signing Petr Čech played for Arsenal in the 2015 FA Community Shield, a 1–0 win over rivals Chelsea. On 11 August, he joined Championship side Wolverhampton Wanderers on a season-long loan.  On 5 April 2017, Martinez made his first league start of the 2016/17 season as Arsenal beat West Ham 3–0.  On 2 August 2017, he was loaned to La Liga side Getafe CF on a one-year deal.  On 23 January 2019, he was loaned to Championship side Reading until the end of the season. He made his debut on 29 January against Bolton. A few days later he won man of the match against Aston Villa.

International career.

He was called up to the Argentina senior squad to replace Óscar Ustari to face Nigeria in June 2011. He received his second senior call up against Germany and Ecuador on 9 and 13 October 2019, he was an unused substitute for both friendly matches.

Personal life.

Martinez is currently sponsored by Puma.

Honours.

Arsenal  Argentina

Damián Emiliano Martínez Romero (, born 2 September 1992) is an Argentine professional footballer who plays as a goalkeeper for club Arsenal.

Damián Emiliano Martinez (* 2. září 1992, Mar del Plata, Argentina) je argentinský fotbalový brankář. V červnu 2011 byl poprvé povolán do seniorské reprezentace Argentiny, kde nahradil Oscara Ustariho. Na svůj debut v reprezentačním výběru stále čeká.


Background.

In 1980, Jon Bon Jovi (born: John Francis Bongiovi) began work at Power Station Studios, a Manhattan recording facility where his cousin, Tony Bongiovi, was a co-owner. Jon made several demos and sent them out to record companies, but failed to make an impact.  In 1982, Jon went to local radio station WAPP 103.5FM "The Apple". DJ Chip Hobart listened to the demos and loved "Runaway", deciding to include it on the station's compilation album of local homegrown talent. The studio musicians who helped record "Runaway" were known as The All Star Review. They were: guitarist Tim Pierce, keyboardist Roy Bittan, drummer Frankie LaRocka, bass guitarist Hugh McDonald, and additional singers David Grahmme and Mick Seeley (Seeley also composed the distinctive keyboard riff that opens the song). McDonald would later replace Alec John Such as Bon Jovi's bass guitarist.  The song began to get airplay around New York. Jon signed to Mercury Records, part of the PolyGram company. He wanted a band name and the A&R staff at PolyGram came up with Bon Jovi.  In March 1983, Bon Jovi called David Bryan (then known as Rashbaum), who in turn called bass guitarist Alec John Such and an experienced drummer named Tico Torres. At that time Bon Jovi's lead guitarist was Dave Sabo, who later formed the band Skid Row. Sabo was soon replaced by Richie Sambora.  "We weren't a good band", Bon Jovi said in 2007. "We didn't become a good band until the third record, but we had a drummer who could keep time, which you should never take for granted. But I did okay for a 22-year-old. I'd only been in a studio for three years total prior to that record and I didn't know anything about comping a vocal – where you take a word or a line from one track and piece it together. I was thinking, My god, I'm so bad that they have to put my vocals together for me. The engineer was saying, Don't fret, Jon: even Freddie Mercury and the greats have to comp a vocal."

Release and reception.

AllMusic has retrospectively rated "Bon Jovi" three-and-a-half out of five stars. Leslie Mathew, who reviewed the album, said: "The songs may be simple and the writing prone to all clichés of the form, but the album boasts a pretty consistent hard rock attack, passionate playing, and a keen sense of melody."

Personnel.

Bon Jovi  Additional musicians  Engineers  Album Design-Spencer Drate, Judith Salavetz  Photography-Geoffrey Hargrave Thomas

Bon Jovi is the self-titled debut studio album by American rock band Bon Jovi, released on January 21, 1984. Produced by Tony Bongiovi and Lance Quinn, it is significant for being the only Bon Jovi album in which a song ("She Don't Know Me") appears that was not written or co-written by a member of the band. The album charted at No. 43 on the U.S. "Billboard" 200.

Bon Jovi je debutové album stejnojmenné americké hard rockové hudební skupiny Bon Jovi, které bylo vydáno 21. ledna 1984. Album produkovali Tony Bongiovi, bratranec Jona Bon Joviho a Lance Quinn. Je to jediné album, na kterém se nachází píseň („She Don't Know Me“), na jejímž textu se nijak nepodíleli členové kapely. Album se umístilo na 43. pozici žebříčku Billboard 200.


Background.

Recorded in six weeks between January and March 1985, at the Warehouse Studios in Philadelphia, Pennsylvania, the album marked the final collaboration between Bon Jovi and producer Lance Quinn. It is the only Bon Jovi album to feature songwriting by four of the band members; "Secret Dreams" is the only Bon Jovi song to date for which drummer Tico Torres receives a writing credit.  Despite being a fan favorite, the band was unsatisfied with the sound of the album and essentially disowned it once they had solidified their status as worldwide superstars with "Slippery When Wet" and "New Jersey". It is the least represented album in their setlists over the course of the career: nothing from "7800° Fahrenheit" was performed after the New Jersey Syndicate Tour, but a few performances of “Tokyo Road” in Japan during the 1990s, a few performances of “Only Lonely” during The Circle Tour in 2010, and one performance of “Tokyo Road” in Hawaii, also during The Circle Tour.  "I always overlook the second album," noted Jon Bon Jovi in 2007. "Always have, always will. We had no time to make it and we didn't know who we were... We did whatever producer Lance Quinn said. He was a brilliant guitarist and had made with Talking Heads, so you listened."  "All of us were going through tough times on a personal level," he explained at the time of "Slippery When Wet"'s release. "And the strain told on the music we produced. It wasn't a pleasant experience... Lance Quinn wasn't the man for us, and that added to the feeling that we were going about it badly. None of us want to live in that mental state ever again. We've put the record behind us, and moved on."

7800° Fahrenheit is the second studio album by American rock band Bon Jovi. It was released on March 27, 1985, through Mercury Records. The album's title was a reference to the supposed melting point of rock, equivalent to 4313° Celsius; as the Fahrenheit scale is mainly used only in the United States, "7800° Fahrenheit" thus suggested "American hot rock."

7800° Fahrenheit je v pořadí druhé studiové album americké hard rockové hudební skupiny Bon Jovi. Album vyšlo 27. března 1985, rok po vydání debutového alba "Bon Jovi". Název alba vychází z předpokládané teploty tání skály (7800 °F je asi 4300 °C). Album také přineslo nové logo skupiny, které pak kapela použila i na albech "Slippery When Wet" (1986) a "New Jersey" (1988).


Background.

Guam is the southernmost part of the Mariana Islands in the Pacific Ocean. It is the largest of the islands, with an area of 225 square miles. Guam's interior is rugged, with heavy tropical forests in the north of the island and wooded hills in the south. Much of the island's coastline is edged with coral reefs and cliffs, though beaches suitable for landing troops exist in the center of the west coast. Guam has a tropical climate, though December forms part of the dry season.  The United States captured Guam from the Kingdom of Spain on 21 June 1898 during the Spanish–American War. The next year Spain sold the other islands in the Marianas chain to Germany. The United States Navy established a facility near the village of Piti on Guam in 1899, and the United States Marine Corps (USMC) opened a barracks at Sumay in 1901. A naval coaling station was established on the island in 1905, and a battery of six guns was emplaced to strengthen Guam's defenses in 1909. A U.S. Navy captain served as both the Governor and commander of the naval base from 1899 onwards, though there were some elements of a civilian government on the island.  During World War I, Japanese forces captured the German islands in the Marianas during October 1914 and established a garrison which was designated the South Seas, Defense Force. Japan gained a mandate over the islands from the League of Nations in December 1920, and they were administered by the South Seas Bureau which formed part of the Ministry of Overseas Affairs. Japanese colonists were permitted to settle in the Marianas, and by the late 1930s there were more colonists than natives in the Japanese islands. In 1935 the Japanese Government banned westerners from entering its mandated islands in the Pacific, and in 1939 established the 4th Fleet to defend the region.  While the United States considered increasing Guam's defenses during and after World War I, no action was taken other than to deploy a USMC seaplane unit to the island in 1921. The outcomes of the 1922 Washington Naval Conference included an agreement by both the United States and Japanese governments that they would not fortify the islands they administered in the western Pacific, including the Marianas. As a result, no further improvements were made to Guam's defenses during the 1920s and 1930s, and the island's coastal artillery battery was removed by 1930. The USMC seaplane unit also departed the next year. The Navy sought permission to build fortifications on the island in 1938, but this proposal was rejected. In 1941 Guam had a population of 23,394, most of whom lived in or within of the island's capital of Agana. The island had about of improved roads and Apra Harbor was considered the best in the Marianas, but did not have an airfield.

Prelude.

Japanese plans for the Pacific War included capturing Guam within the war's first days. From March 1941, Japanese aircraft flew photo reconnaissance sorties over the island. Plans for the invasion of the island were completed in September of that year, and the South Seas Detachment was selected as the main unit responsible for this. The South Seas Detachment comprised the 144th Infantry Regiment and other units detached from the 55th Division and had a strength of 4,886 men. The South Seas Detachment was concentrated in Korea during November 1941 and, following a brief stay in Japan, sailed for Chichi-jima in the Bonin Islands late that month. The 370-man strong 5th Company of the 2nd Maizuru Special Naval Landing Force, which was based at Saipan in the Marianas, was also assigned to join the assault on Guam. These units would be transported to Guam by nine transports escorted by the minelayer "Tsugaru" and four destroyers. The 6th Cruiser Division, which comprised four heavy cruisers, was also available to provide support if needed. The landing force and naval units were supported by the 18th Naval Air Corps, which was based at Saipan and equipped with obsolete floatplanes.  The United States government did not believe that it would be possible or practical to defend Guam if it was attacked. The island was not seen as being useful in efforts to reinforce the Philippines, though it served as a refueling point for Pan Am flying boats and was one of the relay points for the Pacific Cable Company's telegraph cable which linked the Philippines to the US west coast. In 1941, the island was given a "Category F" defense rating; this ruled out the construction of new defenses and meant that, when war broke out, Guam's defenders were to destroy all facilities of military value and withdraw. Despite this and with only small arms available to them for their defense, the U.S. Marines stationed on the island and under command of Lt. Col., later, U.S. Marine Corps brigadier general William K. MacNulty fortified their positions and put up a valiant defense against the subsequent Japanese aerial assault of the island, while suffering losses and other casualties of near one third of their complement.  Despite the low priority accorded to Guam, some minor steps were also taken by other commands to improve Guam's defenses before war broke out. A contract for minor improvements to the military facilities on Guam was issued in April 1941, and work began the next month. The Guam Insular Force Guard, which was a locally manned militia force responsible for protecting the naval base, was also slightly expanded in May. On 17 October the dependents of the American military personnel on the island were evacuated to the United States by the transport, followed by more than 1,000 construction workers. On 23 October 1941, the US Navy's General Board provided Secretary of the Navy Frank Knox with a report on Guam's defenses which recommended against reinforcing the island due to the difficulties of defending it and the need to allocate resources to other priorities. The report argued in favor of continuing to improve Guam's harbor and seaplane facilities, however.  At the outbreak of war on 8 December 1941 (local time), Guam was defended by small US Navy and USMC units as well as the Insular Force Guard. Captain George McMillin, who was also the island's governor and the overall commander of the garrison, was in charge of naval forces, Guam, which comprised 271 personnel and four nurses. This force was a subordinate unit of the Asiatic Fleet and most of its personnel were unarmed. Guam's guard ship, the, had sailed to the Philippines to pick up supplies and enable the crew to buy Christmas presents and was directed to remain there. The minesweeper was present at the island, along with the immobile oil depot ship, and two old yard patrol boats "YP-16" and "YP-17" which had been delivered aboard the USS "Ramapo" on 22 October 1940. Marine barracks, Sumay, had a strength of 145 men who were organised into a company armed with rifles and a small number of machine guns. The Insular Force Guard comprised 246 men, most of whom had received little training. The marines and Insular Force Guard were equipped with 170 M1903 Springfield rifles, 13 Lewis Guns and 15 Browning Automatic Rifles. The defenders did not have any mortars or artillery other than the guns on board "Penguin". In addition to these military units, Guam's police force (the Guam Insular Patrol) had a strength of 80 men who were armed only with pistols.

Battle.

At 04:45 on 8 December, the governor of the island, George McMillin, was informed about the attack on Pearl Harbor. At 08:27, Japanese land-based aircraft from Saipan attacked the marine barracks, Piti Navy Yard, Libugon radio station, Standard Oil Company, and the Pan American Hotel. During the air attack, the minesweeper USS, the largest navy vessel at the island, was sunk after shooting down at least one Japanese airplane. One officer was killed and several men wounded. The air raids all over Guam continued into the morning and afternoon before subsiding at 17:00.  The next day, at 08:30, Japanese air attacks resumed, with no more than nine aircraft attacking at a time. The same targets as the previous day were attacked, and also the Government House in Agana and several villages. That evening, a Japanese invasion fleet of four heavy cruisers, four destroyers, two gunboats, six submarine chasers, two minesweepers and two destroyer tenders left Saipan for Guam. A mistake in their intelligence gathering had caused the Japanese to overcommit resources and attack Guam with disproportionate force.  The Japanese landed about 400 troops of the 5th Defence Force from Saipan on Guam in the early morning of 10 December 1941, at Dungcas Beach, north of Agana. They attacked and quickly defeated the Insular Force Guard in Agana. They then advanced on Piti, moving toward Sumay and the marine barracks. The principal engagement took place on Agana's Plaza de Espana at 04:45 when a few marines and Insular Force guardsmen fought with the Japanese naval soldiers. After token post-invasion resistance, the Marines, on Governor McMillin's orders, surrendered at 05:45. Governor McMillin officially surrendered at 06:00. A few skirmishes took place all over the island before news of the surrender spread and the rest of the island forces laid down their arms. The American patrol boat "YP-16" was scuttled by means of fire during the event and "YP-17" was captured by Japanese naval forces. An American freighter was damaged by the Japanese.  In the meantime the Japanese South Seas Detached Force (about 5,500 men) under the command of Major-General Tomitarō Horii made separate landings at Tumon Bay in the north, on the southwest coast near Merizo, and on the eastern shore of the island at Talofofo Bay.  U.S. Marines' losses were five killed and 13 wounded (including the prior Japanese air assault of the island, the marines' losses were 13 dead and 37 wounded). The U.S. Navy lost eight killed while four of the Guam Insular Force Guards were killed and 22 others wounded. One Japanese naval soldier was killed and six wounded. Pfc Kauffman was killed by the Japanese after the surrender.  Thirteen American civilians were killed by the Japanese during the battle. Six U.S. Navy seamen decided to evade capture from the Japanese rather than surrender; five were eventually captured by the Japanese and beheaded. George Ray Tweed, a U.S. Navy radioman and one of the original six men, managed to survive with the help of local Chamorros. They moved him from village to village, sometimes endangering their own families for his protection. The Japanese knew that an unknown American could not hide without some form of help. Consequently, Chamorro suspects were questioned, tortured, and beheaded. Despite the horrific abuses, Chamorros loyal to the United States protected Tweed. The radioman managed to covertly endure throughout the two and one-half years of occupation.

The First Battle of Guam was an engagement during the Pacific War in World War II, and took place from 8 December to 10 December 1941 on Guam in the Mariana Islands between Japan and the United States. The American garrison was defeated by Japanese forces on 10 December, which resulted in an occupation until the Second Battle of Guam in 1944.

První bitva o Guam byla jedna z prvních bitev za války v Tichomoří mezi Američany a Japonci. Odehrála se na Marianském ostrově Guam. Začala 8. prosince 1941 vyloděním japonské námořní pěchoty a skončila o dva dny později dobytím ostrova. Jednalo se o první americké území, které za války padlo do japonských rukou. Ostrov byl v japonské okupaci až do roku 1944 kdy byl ostrov znovudobyt Američany během operace Forager.