In the online binary options industry, where the contracts are sold by a broker to a customer in an OTC manner, a different option pricing model is used.

Brokers sell binary options at a fixed price e. Some brokers, also offer a sort of out-of-money reward to a losing customer. On non-regulated platforms, client money is not necessarily kept in a trust account, as required by government financial regulation , and transactions are not monitored by third parties in order to ensure fair play. Binary options are often considered a form of gambling rather than investment because of their negative cumulative payout the brokers have an edge over the investor and because they are advertised as requiring little or no knowledge of the markets.

Gordon Pape, writing in Forbes. com in , called binary options websites "gambling sites, pure and simple", and said "this sort of thing can quickly become addictive no one, no matter how knowledgeable, can consistently predict what a stock or commodity will do within a short time frame". Pape observed that binary options are poor from a gambling standpoint as well because of the excessive "house edge".

Let's say you make 1, "trades" and win of them. In other words, you must win The U. Commodity Futures Trading Commission warns that "some binary options Internet-based trading platforms may overstate the average return on investment by advertising a higher average return on investment than a customer should expect given the payout structure.

In the Black—Scholes model , the price of the option can be found by the formulas below. This pays out one unit of cash if the spot is above the strike at maturity.

Its value now is given by. This pays out one unit of cash if the spot is below the strike at maturity. This pays out one unit of asset if the spot is above the strike at maturity.

This pays out one unit of asset if the spot is below the strike at maturity. Its value now is given by:. call is worth exactly one unit. The price of a cash-or-nothing American binary put resp. The above follows immediately from expressions for the Laplace transform of the distribution of the conditional first passage time of Brownian motion to a particular level. Similarly, paying out 1 unit of the foreign currency if the spot at maturity is above or below the strike is exactly like an asset-or nothing call and put respectively.

The Black—Scholes model relies on symmetry of distribution and ignores the skewness of the distribution of the asset. The skew matters because it affects the binary considerably more than the regular options. A binary call option is, at long expirations, similar to a tight call spread using two vanilla options. Thus, the value of a binary call is the negative of the derivative of the price of a vanilla call with respect to strike price:.

Skew is typically negative, so the value of a binary call is higher when taking skew into account. Since a binary call is a mathematical derivative of a vanilla call with respect to strike, the price of a binary call has the same shape as the delta of a vanilla call, and the delta of a binary call has the same shape as the gamma of a vanilla call.

Many binary option "brokers" have been exposed as fraudulent operations. Manipulation of price data to cause customers to lose is common. Withdrawals are regularly stalled or refused by such operations; if a client has good reason to expect a payment, the operator will simply stop taking their phone calls.

On 23 March , The European Securities and Markets Authority , a European Union financial regulatory institution and European Supervisory Authority located in Paris, agreed to new temporary rules prohibiting the marketing, distribution or sale of binary options to retail clients. The Australian Securities and Investments Commission ASIC warned Australian investors on 13 February against Opteck, an unlicensed binary option provider.

In August , Belgium's Financial Services and Markets Authority banned binary options schemes, based on concerns about widespread fraud. No firms are registered in Canada to offer or sell binary options, so no binary options trading is currently allowed. Provincial regulators have proposed a complete ban on all binary options trading include a ban on online advertising for binary options trading sites. On May 3, , the Cyprus Securities and Exchange Commission CySEC announced a policy change regarding the classification of binary options as financial instruments.

The effect is that binary options platforms operating in Cyprus, where many of the platforms are now based, would have to be CySEC regulated within six months of the date of the announcement. CySEC was the first EU MiFID -member regulator to treat binary options as financial instruments. In , CySEC prevailed over the disreputable binary options brokers and communicated intensively with traders in order to prevent the risks of using unregulated financial services.

On September 19, , CySEC sent out a press release warning investors against binary options broker TraderXP, who was not and had never been licensed by CySEC. CySEC also temporarily suspended the license of the Cedar Finance on December 19, , because the potential violations referenced appeared to seriously endanger the interests of the company's customers and the proper functioning of capital markets, as described in the official issued press release.

CySEC also issued a warning against binary option broker PlanetOption at the end of the year and another warning against binary option broker LBinary on January 10, , pointing out that it was not regulated by the Commission and the Commission had not received any notification by any of its counterparts in other European countries to the effect of this firm being a regulated provider.

OptionBravo and ChargeXP were also financially penalized. CySEC also indicated that it had voted to reject the ShortOption license application. In , CySEC repeatedly fined Banc De Binary for several violations including the solicitation of U. In August , France's Sapin II bill on transparency was announced by the Autorité des Marchés Financiers AMF , seeking to outlaw all financial derivatives advertising.

The AMF stated that it would ban the advertising of certain highly speculative and risky financial contracts to private individuals by electronic means. The French regulator is determined to cooperate with the legal authorities to have illegal websites blocked. This ban was seen by industry watchers as having an impact on sponsored sports such as European football clubs.

The Cyprus-based company 24Option [46] was banned from trading in France by AMF earlier in German Federal Financial Supervisory Authority BaFin has been regularly publishing investor warnings. On November 29, , BaFin announced that it is planning to "prohibit the marketing, distribution and sale of binary options to retail clients at a national level". According to the Commodity Futures Trading Regulatory Agency CoFTRA in Indonesia, also known as BAPPEBTI, binary options are considered a form of online gambling and is illegal in the country.

The move to delegalize binary options stems from concerns that the public may be swayed by misleading advertisements, promotions, and offers to participate in fraudulent practices that operate under the guise of binary options trading.

In March binary options trading within Israel was banned by the Israel Securities Authority , on the grounds that such trading is essentially gambling and not a form of investment management.

The ban was extended to overseas clients as well in October In The Times of Israel ran several articles on binary options fraud. In July the Israeli binary option firms Vault Options and Global Trader were ordered by the U. The companies were also banned permanently from operating in the United States or selling to U.

In November the Israel Securities Authority carried out a raid on the Ramat Gan offices of binary option broker iTrader. The CEO and six other employees were charged with fraud, providing unlicensed investment advice, and obstruction of justice.

On May 15, , Eliran Saada, the owner of Express Target Marketing , which has operated the binary options companies InsideOption and SecuredOptions, was arrested on suspicion of fraud, false accounting, forgery, extortion , and blackmail. In August Israeli police superintendent Rafi Biton said that the binary trading industry had "turned into a monster".

He told the Israeli Knesset that criminal investigations had begun. In September , the FBI arrested Lee Elbaz, CEO of binary options trading company Yukom Communications, upon her arrival in the United States. They arrested her for wire fraud and conspiracy to commit wire fraud. In February , the FBI arrested Austin Smith, Founder of Wealth Recovery International, after his arrival in the United States. Smith was arrested for wire fraud due to his involvement as an employee of Binarybook.

In March the Malta Financial Services Authority MFSA announced that binary options regulation would be transferred away from Malta's Lottery and Gaming Authority. This required providers to obtain a category 3 Investment Services license and conform to MiFID's minimum capital requirements ; firms could previously operate from the jurisdiction with a valid Lottery and Gaming Authority license.

In April , New Zealand 's Financial Markets Authority FMA announced that all brokers that offer short-term investment instruments that settle within three days are required to obtain a license from the agency.

In the UK, binary options were regulated by the Gambling Commission rather than the Financial Conduct Authority FCA. They stated that binary options "did not appear to meet a genuine investment need". The Isle of Man , a self-governing Crown dependency for which the UK is responsible, has issued licenses to companies offering binary options as "games of skill" licensed and regulated under fixed odds betting by the Isle of Man Gambling Supervision Commission GSC.

On October 19, , London police raided 20 binary options firms in London. Fraud within the market is rife, with many binary options providers using the names of famous and respectable people without their knowledge.

The City of London police in May said that reported losses for the previous financial year were £13 million, increased from £2 million the year before. In the United States, the Securities and Exchange Commission SEC approved exchange-traded binary options in AMEX now NYSE American offers binary options on some exchange-traded funds and a few highly liquid equities such as Citigroup and Google.

On the exchange binary options were called "fixed return options" FROs. To reduce the threat of market manipulation of single stocks, FROs use a "settlement index" defined as a volume-weighted average of trades on the expiration day.

AMEX and Donato A. Montanaro submitted a patent application for exchange-listed binary options using a volume-weighted settlement index in NADEX , a U. They do not participate in the trades. On June 6, , the U. CFTC and the SEC jointly issued an Investor Alert to warn about fraudulent promotional schemes involving binary options and binary options trading platforms.

The two agencies said that they had received numerous complaints of fraud about binary options trading sites, "including refusal to credit customer accounts or reimburse funds to customers; identity theft ; and manipulation of software to generate losing trades".

Other binary options operations were violating requirements to register with regulators. In June , U. regulators charged Israeli-Cypriot company Banc De Binary with illegally selling binary options to U. Regulators found the company used a "virtual office" in New York's Trump Tower in pursuit of its scheme, evading a ban on off-exchange binary option contracts. The company neither admitted nor denied the allegations. In February The Times of Israel reported that the FBI was conducting an active international investigation of binary option fraud, emphasizing its international nature, saying that the agency was "not limited to the USA".

Victims from around the world were asked to contact an FBI field office or the FBI's Internet Crime Complaint Center. The investigation is not limited to the binary options brokers, but is comprehensive and could include companies that provide services that allow the industry to operate.

Credit card issuers will be informed of the fraudulent nature of much of the industry, which could possibly allow victims to receive a chargeback , or refund, of fraudulently obtained money. On March 13, , the FBI reiterated its warning, declaring that the "perpetrators behind many of the binary options websites, primarily criminals located overseas, are only interested in one thing—taking your money".

They also provide a checklist on how to avoid being victimized. There is also a popular binary options recovery services scam, where fraudsters promise to "hunt" down the binary options scammers and retrieve the money from them through legal methods. From Wikipedia, the free encyclopedia. Financial exotic option with an all-or-nothing payoff. Further information: Foreign exchange derivative.

Further information: Securities fraud. Journal of Business , — GPS Visualizer will now honor those colors, unless you change the "Preserve colors and widths from input files" setting in the Advanced Track Options to "No.

dat" files generated by GiSTEQ PhotoTrackr. This should be helpful if you want to manually control the colors of the tracks in uploaded GPS files.

In the future, GPS Visualizer may include support for colors in GPX output from the conversion utility. Note that flickr. com URLs must include your user ID in the N09 format. You can paste your InstaMapper feed URL into GPSV's Google Maps input form -- either as "static" or "dynamic" data.

In the future, that code may be altered so that ALL data files not just plain text can have their type altered -- e. log files from the Xplova G3 bike computer.

Geonaute Keymaze. ghd" file. Those files can now be read directly by GPS Visualizer. But because pace is an "inverse" function, it will be very large when travelling at slow speeds. So you may want to manually set the maximum colorization or y-axis value when using pace on your map or profile.

The "moving average" option in the conversion and profile forms might also be helpful. GPS Visualizer can now read the new time-stamped tracks -- but it can't create them yet. There are two versions: one is complete, the other omits place names and man-made structures. Whether the NRCan maps are better than the MyTopo. com layer available in Google Maps is a matter of opinion. fit suffix; GPS Visualizer can now read basic information from these files time, latitude, longitude, altitude, speed.

pwx files from the Timex Global Trainer wrist-mounted GPS system; the files are associated with "TrainingPeaks" software from Peaksware. nmeadb" extension -- which apparently come from "Navibe" GPS receivers -- are now supported by GPS Visualizer. tcx file that contains "Course Points" left, right, straight, summit, valley, water, etc.

The points will also appear in Google Earth, but without the fancy Garmin icons. VMG is available as a colorization parameter in maps , or as an added field in plain-text conversion. It works just like the existing "synthesize descriptions" feature, using field names in {curly brackets}. ltf files from the Windows Mobile application "LiteTrack" are now supported.

They're simple text files, but with some unusual formatting that had to be accounted for. This new feature is called The Atlas. Unlike normal GPS Visualizer maps, which are deleted after a few days, links to Atlas maps should work forever as long as your data remains online.

Learn more. frequently end up with corrupt data in them, usually in the "gpxx:Address" or "gpxx:PhoneNumber" extensions. GPS Visualizer will try to overcome this corruption by eliminating "bad" bytes before processing your files. txt format from the Bendix King AV8OR handheld GPS. trk files from the latest version of the "iGO" software iGO Primo. As always, all formats should be automatically detected. Look for the new menu near the bottom of the "advanced options" section. In fact, if you separate a list of distances with commas e.

GPS Visualizer will now read that extended data, which means it can then be used in "synthesized" names, descriptions, or labels. See the map form's help file for more info on synthesizing fields with GPS Visualizer. Read more about manually creating input files in the waypoints tutorial. This week, two more patches have been added to GPSV's code specifically to deal with more of Garmin's bugs.

Sport Tracker. gst files from the " GPS Sport Tracker " application for Windows Mobile. Second, you can make it so tracks are not "clickable" in Google Maps; this may allow very complex maps to load a bit faster. Both new items are in the "advanced" track options. Garmin Edge raw. dat files that are found in a Garmin Edge's file system when it's connected to your computer e.

Turns out they're a lot like. tcx files, but with a bit less information in them. In the future, updates that are posted down here will also go on the Facebook page. To get GPSV updates on your Facebook feed, be sure to click the "Like" button.

gpsed files from the " GPSed " BlackBerry app. Wintec WBT tes suffix from the Wintec WBT Bluetooth Data Logger. logg files produced by Canmore GPS loggers -- for example, the Canmore GTF L. Jeppesen FliteStar. These files normally have a. xml or. fpl extension. Note that FliteStar's route packs binary.

rpk files are not supported. This could be helpful if you want to show a specific location to a friend, using the background map of your choice. See the waypoint tutorial for more on customizing and fine-tuning Google Maps. Chrysler MyGig. Despite the waypoint-like filename suffix, these are actually time-stamped tracklogs. bin" files from Magellan Roadmate GPS which are really just standard NMEA data wrapped up in some binary junk ; and ".

pvt" files from Magellan Maestro GPS units. For the. pvt files, only latitude and longitude are supported so far; more sample data is needed before the other fields can be confidently decoded.

Until now, the icons used have been the ones displayed on the GPSMAP series of devices, but now you have to option to either use the small 16x16 icons from GPSMAP , or the newer, larger 24x24 icons that come with the newer versions of Garmin's applications. Look in the "advanced" section of the waypoint section of the Google Maps form to enable the larger icons if you want them. The appearance of the maps themselves hasn't changed, but the JavaScript commands that build the various configurable options are formatted differently.

In the new format, they take up a little more room but should be a little easier to follow, and there are more helpful comments at the end of each line, in case you want to edit the HTML yourself. They're available in any color and opacity. Just be sure to label the columns correctly; you need one for UTM Zone, one for Easting, and one for Northing.

The ellipsoid will be assumed to be WGS ppg or. tr7 files ; MemoryMap. mmo files ; Nokia Sports Tracker XML export files; and a weird old Garmin text format whose header begins with "Garmin:Trk:L". DAT" from Northstar marine GPS systems; the files are a modified NMEA format where each line begins with "". Routes in these files which are basically lists of waypoints should be supported as well. If you select the text in a table containing track log data on flightaware. com , you can paste it into GPS Visualizer's input forms to map it , see it in Google Earth , or convert it to GPX.

Supplying the URL of a FlightAware tracklog page will work too. Excel xlsx files to GPS Visualizer. However, copying and pasting from your worksheet into the input forms is still quicker and easier in many cases! trk from Fugawi navigation software. Time stamps may or may not work properly, depending on the version. These files, typically called "gps. bin" in the device's file system, can now be read by GPS Visualizer.

See GpsPasSion for a thorough discussion about these tracklogs and how to enable and access them on your Nüvi. bin files from Sonocaddie devices, which record your track on a golf course. Note that the files must retain the default name of "RecordTrack.

bin" or "RecordShotTrack. bin" for GPS Visualizer to recognize them as Sonocaddie files. Drawing the axis labels is the new default behavior; if you want to turn them off, open the "advanced options" in the General Parameters section. Of course, as always, you can also supply the URL of a graphic on the Web, but keep in mind that only the built-in ones can be colorized or made semi-opaque.

org as the background. TMQ C-Plot. usr or. Support for C-Plot tracklogs should be coming soon. For example, you can only let in the first X or last X markers e. This filtering needs to be applied by editing the map's HTML after it's been created, so contact me if you have questions on how to set it up.

Note that unlike some other improvements, this one is not retroactive; maps created before today will not have clickable polylines. Just keep in mind that in Google Maps, you can't apply a color to a custom icon. Select "custom icon" from the bottom of the marker icon drop-down menu, and a box will appear where you can enter the URL of your image. gpm files from GPSMeter PDA , an application for measuring areas and lengths with a GPS-enabled PDA or mobile phone.

GPSLogger binary files have a suffix of ". gpl"; it's the same file extension as DeLorme tracklogs, but GPS Visualizer can detect the difference in the structure of the files. Note that only polygons are supported so far; more WKT support may be added if there is demand for it.

Read more about elevation data. org as the background; supposedly, in some areas, they have more detail than Google's street data. Due to a bug in Google's KML output functions, previously only the first leg of the trip would be mapped. Just plan your trip in Google Maps , then click the "Link" button to get a URL that you can paste into GPS Visualizer's input forms. csv route files ; from Silva Multi-Navigator. cwp waypoint files,. ctr track files, and.

crt route files ; and. nav" or "gpsdata. nav"; if you know the source, please tell me. Look for the "Add SRTM elevation data" menu in the profile , conversion , and Google Earth input forms, or read more on the Elevation Lookup Utility page.

It's not orders of magnitude better than the old setup, but it's definitely faster and has 4 times as much memory; hopefully those midday overloads will a bit be less frequent.

Clicking the track's name still toggles the track's visibility. It also has the ability to use Google again. csv export files from locate-gps. com , the online service associated with tracking devices such as the Espace Mobilité "Locate Box" or the Flextrack "Lommy. trk files from Nav-N-Go's "iGO" software for Windows Mobile devices are now able to be detected and read by GPS Visualizer's mapper and converter.

gst files are now supported by GPS Visualizer. ngt files from the PocketPC program NoniGPSPlot are now supported by GPS Visualizer. When the spreadsheet is updated, the map will be updated! See an example here ; to try it with your data, paste its location into the "URL that will be loaded into the map dynamically" box in the Google Maps input form.

And make sure your spreadsheet is "published," preferably using the "auto-publish" feature. Note that if you want to use data from a Google Spreadsheet but DON'T want the map to be dynamically updated, you can supply its URL in the "static data" box.

An example map is here. There's no limit to how much stuff you can load into a description; just insert existing field names by surrounding them in {curly brackets}, and include any HTML tags you want. Note that any existing "desc" field you may have supplied will be overwritten, although you can use it in the new description by including {desc} ; this might be useful to, for example, quickly apply a style or color to all descriptions.

This new feature should be easier than having to dump your data into Excel and building text formulas. To see how it works, look in the source of this example page , and feel free to drop me a note if you have questions. Note that GPS Visualizer will not automatically truncate and compile 5-digit ZIPs; you must reduce them before uploading. It's easy to do it in Excel. Look for "tickmark interval" in the advanced track options.

It's also handy for exploring alternate background imagery e. Most of the parameters you'd want to change are in an easy-to-edit list in the guts of the page. And despite the fact that this is the first "news" item in almost 4 months, smaller updates are happening all the time Instead of a circle, they are now represented by arrows pointing the appropriate direction.

You can also manually rotate any waypoint's icon by including a "rotation" field in your plain-text data. This may be very helpful for things like mapping digital photos. Before, you needed to enter a latitude and longitude for each point. Before, you could do it, but it was slow because they had to be fetched from a remote site.

Donations to offset the cost of the new data would, of course, be much appreciated! csv track files that each produces. xls spreadsheet files from Microsoft Excel. Of course, a header row is still required.

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As a clinical geneticist, Paul James is accustomed to discussing some of the most delicate issues with his patients. But in early , he found himself having a particularly awkward conversation about sex. A year-old pregnant woman had visited his clinic at the Royal Melbourne Hospital in Australia to hear the results of an amniocentesis test to screen her baby's chromosomes for abnormalities. The baby was fine — but follow-up tests had revealed something astonishing about the mother.

Her body was built of cells from two individuals, probably from twin embryos that had merged in her own mother's womb. And there was more. One set of cells carried two X chromosomes, the complement that typically makes a person female; the other had an X and a Y. Halfway through her fifth decade and pregnant with her third child, the woman learned for the first time that a large part of her body was chromosomally male 1. Sex can be much more complicated than it at first seems. According to the simple scenario, the presence or absence of a Y chromosome is what counts: with it, you are male, and without it, you are female.

But doctors have long known that some people straddle the boundary — their sex chromosomes say one thing, but their gonads ovaries or testes or sexual anatomy say another. Parents of children with these kinds of conditions — known as intersex conditions, or differences or disorders of sex development DSDs — often face difficult decisions about whether to bring up their child as a boy or a girl.

Some researchers now say that as many as 1 person in has some form of DSD 2. When genetics is taken into consideration, the boundary between the sexes becomes even blurrier. Scientists have identified many of the genes involved in the main forms of DSD, and have uncovered variations in these genes that have subtle effects on a person's anatomical or physiological sex. What's more, new technologies in DNA sequencing and cell biology are revealing that almost everyone is, to varying degrees, a patchwork of genetically distinct cells, some with a sex that might not match that of the rest of their body.

Some studies even suggest that the sex of each cell drives its behaviour, through a complicated network of molecular interactions. These discoveries do not sit well in a world in which sex is still defined in binary terms. Few legal systems allow for any ambiguity in biological sex, and a person's legal rights and social status can be heavily influenced by whether their birth certificate says male or female. That the two sexes are physically different is obvious, but at the start of life, it is not.

Five weeks into development, a human embryo has the potential to form both male and female anatomy. Next to the developing kidneys, two bulges known as the gonadal ridges emerge alongside two pairs of ducts, one of which can form the uterus and Fallopian tubes, and the other the male internal genital plumbing: the epididymes, vas deferentia and seminal vesicles.

At six weeks, the gonad switches on the developmental pathway to become an ovary or a testis. If a testis develops, it secretes testosterone, which supports the development of the male ducts. It also makes other hormones that force the presumptive uterus and Fallopian tubes to shrink away.

If the gonad becomes an ovary, it makes oestrogen, and the lack of testosterone causes the male plumbing to wither. The sex hormones also dictate the development of the external genitalia, and they come into play once more at puberty, triggering the development of secondary sexual characteristics such as breasts or facial hair. Changes to any of these processes can have dramatic effects on an individual's sex.

Gene mutations affecting gonad development can result in a person with XY chromosomes developing typically female characteristics, whereas alterations in hormone signalling can cause XX individuals to develop along male lines.

For many years, scientists believed that female development was the default programme, and that male development was actively switched on by the presence of a particular gene on the Y chromosome. In , researchers made headlines when they uncovered the identity of this gene 3 , 4 , which they called SRY. Just by itself, this gene can switch the gonad from ovarian to testicular development. For example, XX individuals who carry a fragment of the Y chromosome that contains SRY develop as males.

By the turn of the millennium, however, the idea of femaleness being a passive default option had been toppled by the discovery of genes that actively promote ovarian development and suppress the testicular programme — such as one called WNT4.

XY individuals with extra copies of this gene can develop atypical genitals and gonads, and a rudimentary uterus and Fallopian tubes 5. In , researchers showed 6 that if another key ovarian gene, RSPO1 , is not working normally, it causes XX people to develop an ovotestis — a gonad with areas of both ovarian and testicular development.

These discoveries have pointed to a complex process of sex determination, in which the identity of the gonad emerges from a contest between two opposing networks of gene activity. Changes in the activity or amounts of molecules such as WNT4 in the networks can tip the balance towards or away from the sex seemingly spelled out by the chromosomes.

According to some scientists, that balance can shift long after development is over. Studies in mice suggest that the gonad teeters between being male and female throughout life, its identity requiring constant maintenance. In , researchers reported 7 deactivating an ovarian gene called Foxl2 in adult female mice; they found that the granulosa cells that support the development of eggs transformed into Sertoli cells, which support sperm development.

Two years later, a separate team showed 8 the opposite: that inactivating a gene called Dmrt1 could turn adult testicular cells into ovarian ones. The gonad is not the only source of diversity in sex. A number of DSDs are caused by changes in the machinery that responds to hormonal signals from the gonads and other glands.

Complete androgen insensitivity syndrome, or CAIS, for example, arises when a person's cells are deaf to male sex hormones, usually because the receptors that respond to the hormones are not working.

People with CAIS have Y chromosomes and internal testes, but their external genitalia are female, and they develop as females at puberty. Conditions such as these meet the medical definition of DSDs, in which an individual's anatomical sex seems to be at odds with their chromosomal or gonadal sex. But they are rare — affecting about 1 in 4, people 9. Some researchers now say that the definition should be widened to include subtle variations of anatomy such as mild hypospadias, in which a man's urethral opening is on the underside of his penis rather than at the tip.

The most inclusive definitions point to the figure of 1 in people having some form of DSD, says Vilain see 'The sex spectrum'. The sex spectrum. But beyond this, there could be even more variation. Since the s, researchers have identified more than 25 genes involved in DSDs, and next-generation DNA sequencing in the past few years has uncovered a wide range of variations in these genes that have mild effects on individuals, rather than causing DSDs.

A DSD called congenital adrenal hyperplasia CAH , for example, causes the body to produce excessive amounts of male sex hormones; XX individuals with this condition are born with ambiguous genitalia an enlarged clitoris and fused labia that resemble a scrotum. It is usually caused by a severe deficiency in an enzyme called hydroxylase.

But women carrying mutations that result in a milder deficiency develop a 'non-classical' form of CAH, which affects about 1 in 1, individuals; they may have male-like facial and body hair, irregular periods or fertility problems — or they might have no obvious symptoms at all. Another gene, NR5A1 , is currently fascinating researchers because variations in it cause a wide range of effects 10 , from underdeveloped gonads to mild hypospadias in men, and premature menopause in women.

Many people never discover their condition unless they seek help for infertility, or discover it through some other brush with medicine. Last year, for example, surgeons reported that they had been operating on a hernia in a man, when they discovered that he had a womb The man was 70, and had fathered four children.

Studies of DSDs have shown that sex is no simple dichotomy. But things become even more complex when scientists zoom in to look at individual cells. The common assumption that every cell contains the same set of genes is untrue. Some people have mosaicism: they develop from a single fertilized egg but become a patchwork of cells with different genetic make-ups. This can happen when sex chromosomes are doled out unevenly between dividing cells during early embryonic development.

For example, an embryo that starts off as XY can lose a Y chromosome from a subset of its cells. If most cells end up as XY, the result is a physically typical male, but if most cells are X, the result is a female with a condition called Turner's syndrome, which tends to result in restricted height and underdeveloped ovaries.

This kind of mosaicism is rare, affecting about 1 in 15, people. The effects of sex-chromosome mosaicism range from the prosaic to the extraordinary. A few cases have been documented in which a mosaic XXY embryo became a mix of two cell types — some with two X chromosomes and some with two Xs and a Y — and then split early in development This results in 'identical' twins of different sexes.

There is a second way in which a person can end up with cells of different chromosomal sexes. James's patient was a chimaera: a person who develops from a mixture of two fertilized eggs, usually owing to a merger between embryonic twins in the womb. Another form of chimaerism, however, is now known to be widespread.

Termed microchimaerism, it happens when stem cells from a fetus cross the placenta into the mother's body, and vice versa. It was first identified in the early s — but the big surprise came more than two decades later, when researchers discovered how long these crossover cells survive, even though they are foreign tissue that the body should, in theory, reject. A study in recorded women with fetal cells in their blood as many as 27 years after giving birth 13 ; another found that maternal cells remain in children up to adulthood This type of work has further blurred the sex divide, because it means that men often carry cells from their mothers, and women who have been pregnant with a male fetus can carry a smattering of its discarded cells.

Microchimaeric cells have been found in many tissues. In , for example, immunologist Lee Nelson and her team at the University of Washington in Seattle found XY cells in post-mortem samples of women's brains The oldest woman carrying male DNA was 94 years old.

Other studies have shown that these immigrant cells are not idle; they integrate into their new environment and acquire specialized functions, including in mice at least forming neurons in the brain But what is not known is how a peppering of male cells in a female, or vice versa, affects the health or characteristics of a tissue — for example, whether it makes the tissue more susceptible to diseases more common in the opposite sex. Scientists are now finding that XX and XY cells behave in different ways, and that this can be independent of the action of sex hormones.

He and his colleagues have shown 17 that the dose of X chromosomes in a mouse's body can affect its metabolism, and studies in a lab dish suggest 18 that XX and XY cells behave differently on a molecular level, for example with different metabolic responses to stress.

The next challenge, says Arnold, is to uncover the mechanisms. His team is studying the handful of X-chromosome genes now known to be more active in females than in males. Biologists may have been building a more nuanced view of sex, but society has yet to catch up. True, more than half a century of activism from members of the lesbian, gay, bisexual and transgender community has softened social attitudes to sexual orientation and gender.

Many societies are now comfortable with men and women crossing conventional societal boundaries in their choice of appearance, career and sexual partner. But when it comes to sex, there is still intense social pressure to conform to the binary model. This pressure has meant that people born with clear DSDs often undergo surgery to 'normalize' their genitals.

Such surgery is controversial because it is usually performed on babies, who are too young to consent, and risks assigning a sex at odds with the child's ultimate gender identity — their sense of their own gender.

Intersex advocacy groups have therefore argued that doctors and parents should at least wait until a child is old enough to communicate their gender identity, which typically manifests around the age of three, or old enough to decide whether they want surgery at all.

This issue was brought into focus by a lawsuit filed in South Carolina in May by the adoptive parents of a child known as MC, who was born with ovotesticular DSD, a condition that produces ambiguous genitalia and gonads with both ovarian and testicular tissue.

Parents of children with these kinds of conditions — known as intersex conditions, or differences or disorders of sex development DSDs — often face difficult decisions about whether to bring up their child as a boy or a girl. With ES6, the language now has three different kinds of for loops. Do not goog. requireType 'some. Close banner Close. Imports are done with goog. Add shading to the edges of your photo to highlight a powerful moment.

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