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Three-spined stickleback

The three-spined stickleback (Gasterosteus aculeatus) is a fish native to most inland and coastal waters north of 30°N. It has long been a subject of scientific study for many reasons. It shows great morphological variation throughout its range, ideal for questions about evolution and population genetics. Many populations are anadromous (they live in seawater but breed in fresh or brackish water) and very tolerant of changes in salinity, a subject of interest to physiologists. It displays elaborate breeding behavior (defending a territory, building a nest, taking care of the eggs and fry) and it can be social (living in shoals outside the breeding season) making it a popular subject of inquiry in fish ethology and behavioral ecology. Its antipredator adaptations, host-parasite interactions, sensory physiology, reproductive physiology, and endocrinology have also been much studied. Facilitating these studies is the fact that the three-spined stickleback is easy to find in nature and easy to keep in aquaria.

Description
This species can occasionally reach lengths of 8 cm, but lengths of 3-4 cm at maturity are more common. The body is laterally compressed. The base of the tail is slender. The caudal fin has 12 rays. The dorsal fin has 10–14 rays; in front of it are the three spines that give the fish its name (though some individuals may have only two or four). The third spine (the one closest to the dorsal fin) is much shorter than the other two. The back of each spine is joined to the body by a thin membrane. The anal fin has eight to 11 rays and is preceded by a short spine. The pelvic fins consist of just a spine and one ray. All spines can be locked in an erect position, making the fish extremely hard to swallow by a predator. The pectoral fins are large, with 10 rays. The body bears no scales, but is protected by bony plates on the back, flanks, and belly. Only one ventral plate is present, but the number of flank plates varies greatly across the distribution range and across habitat types (see below); it is normally higher in marine populations (some freshwater populations may in fact lack lateral plates altogether).

Dorsal coloration varies, but tends towards a drab olive or a silvery green, sometimes with brown mottling. The flanks and belly are silvery. In males during the breeding season, the eyes become blue and the lower head, throat, and anterior belly turn bright red. The throat and belly of breeding females can turn slightly pink. A few populations, however, have breeding males which are all black or all white.

Habitat and distribution
The three-spined stickleback is found only in the Northern Hemisphere, where it usually inhabits coastal waters or freshwater bodies. It can live in either fresh, brackish, or salt water. It prefers slow-flowing water with areas of emerging vegetation. It can be found in ditches, ponds, lakes, backwaters, quiet rivers, sheltered bays, marshes, and harbours.

In North America, it ranges along the East Coast from Chesapeake Bay to the southern half of Baffin Island and the western shore of Hudson Bay, and along the West Coast from southern California to the western shore of Alaska and the Aleutian Islands. It can be found throughout Europe between 35 and 70°N. In Asia, the distribution stretches from Japan and the Korean peninsula to the Bering Straits.

Its distribution could be said to be circumpolar were it not for the fact that it is absent from the north coast of Siberia, the north coast of Alaska, and the Arctic islands of Canada.

Variation in morphology and distribution
Three subspecies are currently recognized by the IUCN:
 * G. a. aculeatus is found in most of the species range, and is the subspecies most strictly termed the three-spined stickleback; its common name in Britain is the tiddler, although "tittlebat" is also sometimes used.
 * G. a. williamsoni, the unarmored threespine stickleback, is found only in North America; its recognised range is southern California, though isolated reports have been made of it occurring in British Columbia and Mexico;
 * G. a. santaeannae, the Santa Ana stickleback, is also restricted to North America.

These subspecies actually represent three examples from the enormous range of morphological variation present within three-spined sticklebacks. Hybrids between some of these morphs show foraging disadvantages, a form of reinforcement in the course of speciation. This is evidence for speciation by reinforcement.

Overall these morphs fall into two rough categories, the anadromous and the freshwater forms:

The anadromous form spends most of its adult life eating plankton and fish in the sea, and returns to freshwater to breed. The adult fish are typically between 6 and 10 cm long, and have 30 to 40 lateral armour plates along their sides. They also have long dorsal and pelvic spines. The anadromous form is morphologically similar all around the Northern Hemisphere, such that anadromous fish from the Baltic, the Atlantic and the Pacific all resemble each other quite closely.

Three-spined stickleback populations are also found in freshwater lakes and streams. These populations were probably formed when anadromous fish started spending their entire lifecycle in fresh water, and thus evolved to live there all year round. Freshwater populations are extremely morphologically diverse, to the extent that many observers (and some taxonomists) would describe a new subspecies of three-spined stickleback in almost every lake in the Northern Hemisphere. One consistent difference between freshwater populations and their anadromous ancestors is the amount of body armour, as the majority of freshwater fish only have between none and 12 lateral armor plates, and shorter dorsal and pelvic spines. However, also large morphological differences occur between lakes. One major axis of variation is between populations found in deep, steep-sided lakes and those in small, shallow lakes. The fish in the deep lakes typically feed in the surface waters on plankton, and often have large eyes, with short, slim bodies and upturned jaws. Some researchers refer to this as the limnetic form. Fish from shallow lakes feed mainly on the lake bed, and are often long and heavy bodied with relatively horizontal jaws and small eyes. These populations are referred to as the benthic form.

Since each watershed was probably colonised separately by anadromous sticklebacks, morphologically similar populations in different watersheds or on different continents are widely believed to have evolved independently. A unique population is found in the meromictic Pink Lake in Gatineau Park, Quebec. Populations have been observed rapidly adapting to different conditions, such as in Lake Union, where sticklebacks have lost and regained armor plates in response to pollution from human activity around the watershed.

One aspect of this morphological variation is that a number of lakes contain both a limnetic and a benthic type, and these do not interbreed with each other. Evolutionary biologists often define species as populations that do not interbreed with each other (the biological species concept), thus the benthics and limnetics within each lake would constitute separate species. These species pairs are an excellent example of how adaptation to different environments (in this case feeding in the surface waters or on the lake bed) can generate new species. This process has come to be termed ecological speciation. This type of species pair is found in British Columbia. The lakes themselves only contain three-spined sticklebacks and cutthroat trout, and all are on islands. Tragically, the pair in Hadley Lake on Lasqueti Island was destroyed in the mid-1980s by the introduction of a predatory catfish, and the pair in Enos Lake on Vancouver Island has started to interbreed and are no longer two distinct species. The two remaining pairs are on Texada Island, in Paxton Lake and Priest Lake, and they are listed as Endangered in the Canadian Species at Risk Act.

Other species pairs which consist of a well-armored marine form and a smaller, unarmored freshwater form are being studied in ponds and lakes in south-central Alaska that were once marine habitats such as those uplifted during the 1964 Alaska earthquake. The evolutionary dynamics of these species pairs are providing a model for the processes of speciation which has taken place in less than 20 years in at least one lake. In 1982, a chemical eradication program intended to make room for trout and salmon at Loberg Lake, Alaska, killed the resident freshwater populations of sticklebacks. Oceanic sticklebacks introduced through nearby Cook Inlet recolonized the lake. In just 12 years beginning in 1990, the frequency of the oceanic form dropped steadily, from 100% to 11%, while a variety with fewer plates increased to 75% of the population, with various intermediate forms making up another small fraction. This rapid evolution is thought to be possible through genetic variations that confer competitive advantages for survival in fresh water when conditions shift rapidly from salt to fresh water. However, the actual molecular basis of this evolution still remains unknown.

Although sticklebacks are found in many locations around the coasts of the Northern Hemisphere and are thus viewed by the IUCN as species of least concern, the unique evolutionary history encapsulated in many freshwater populations indicates further legal protection may be warranted.

Diet
In its different forms or stages of life, the three-spined stickleback can be a bottom-feeder (most commonly chironomid larvae and amphipods) or a planktonic feeder in lakes or in the ocean; it can also consume terrestrial prey fallen to the surface. It can cannibalize eggs and fry.

Life history
Many populations take two years to mature and experience only one breeding season before dying, and some can take up to three years to reach maturity. However, some freshwater populations and populations at extreme latitudes can reach maturity in only one year.

Reproduction

Sexual maturation depends on environmental temperature and photo-period. Longer days and warmer days stimulate brighter colouration in males and the development of eggs in females.

From late April, males and females move from deeper waters to shallow areas. There, each male defends a territory where he builds a nest on the bottom. He starts by digging a small pit. He then fills it with plant material (often filamentous algae), sand, and various debris which he glues together with spiggin, a proteinaceous substance secreted from the kidneys. The word spiggin is derived from spigg, the Swedish name for the three-spined stickleback. He then creates a tunnel through the more or less spherical nest by swimming vigorously through it. Nest building typically takes 5–6 hours though it may also be spread out over several days. After this, the male courts gravid females that pass by with a zigzag dance. (In some populations, the male leads the female to the nest, rather than doing the zigzag dance. ) He approaches a female by swimming very short distances left and right, and then swims back to the nest in the same way. If the female follows, the male often pokes his head inside the nest, and may swim through the tunnel. The female then swims through the tunnel as well, where she deposits 40–300 eggs. The male follows to fertilize the eggs. The female is then chased away by the male. For the duration of the eggs' development, the male will chase away other males and non-gravid females. He may, however, court other gravid females (more than one batch of eggs can be deposited in the same nest).

The sequence of territorial courtship and mating behaviours was described in detail by Niko Tinbergen in a landmark early study in ethology. Tinbergen showed that the red colour on the throat of the territorial male acts as a simple sign stimulus, releasing aggression in other males and attracting females. The red colouration may also be used by females as a way to assess male quality. Red colouration is produced from carotenoids found in the diet of the fish. As carotenoids cannot be synthesised de novo, the degree of colouration gives an indication of male quality (ability to find food), with higher-quality males showing more intense colouration. Also, males that bear fewer parasites tend to exhibit brighter red colours. Many studies have shown that females prefer males with brighter red colouration. However, the response to red is not universal across the entire species, with black throated populations often found in peat-stained waters.

The male takes care of the developing eggs by fanning them. He lines himself up with the entrance of the nest tunnel and swims on the spot. The movement of his pectoral fins creates a current of water through the nest, bringing fresh (well-oxygenated) water to the eggs. He does this not only during the day, but throughout the night, as well. Fanning levels tend to increase until the eggs are about to hatch, which takes 7–8 days at 18–20 °C. Fanning levels also increase when the water is poorly oxygenated. Towards the end of the egg development phase, the male often makes holes in the roof and near the rim of the nest, presumably to improve ventilation of the nest during fanning at a time when the eggs are more metabolically active. Once the young hatch, the male attempts to keep them together for a few days, sucking up any wanderers into his mouth and spitting them back into the nest. Afterwards, the young disperse and the nest is either abandoned by the male, or repaired in preparation for another breeding cycle.

In Nova Scotia, a form of three-spined stickleback departs from the usual pattern of parental care. Unlike other sticklebacks that nest on the substrate, Nova Scotian male sticklebacks build nests in mats of filamentous algae. Surprisingly, almost immediately after fertilization, the males disperse the eggs from the nest and resume soliciting females for eggs. Hence, there appears to have been a loss of parental care in this population. Because these males have reduced dorsal pigmentation, resulting a pearlescent white appearance, they have been dubbed "white sticklebacks". It is currently unknown whether they are a distinct species, or simply a morph of the common Atlantic stickleback.

As the breeding cycle of the three-spined stickleback is light and temperature dependent, it is also possible to manipulate breeding in the lab. For example, it is possible to stimulate sticklebacks to breed twice in a calendar year, instead of once, under the right conditions. This can be useful for genetic and behavioural multi-generational studies.

Infection with the cestode parasite Schistocephalus solidus can cause a reduction in egg mass or complete absence of eggs in female three-spined sticklebacks.

Cooperative behavior
Some evidence indicates the existence of cooperative behavior among three-spined sticklebacks, mainly cooperative predator inspection. Predator inspection appears to allow acquisition of information about the risk a potential predator presents, and may deter attack, with the cost being an increased chance of being attacked if the predator proves to be hungry.

Tit for tat strategy
Sticklebacks are known to cooperate in a tit for tat (TFT) strategy when doing predator inspection. The idea behind TFT is that an individual cooperates on the first move and then does whatever its opponent does on the previous move. This allows for a combination of collaborative (it starts by cooperating), retaliatory (punishes defection), and forgiving (respond to cooperation of others, even if they had defected previously) behavioral responses. When three-spined sticklebacks approaching a live predator were provided with either a simulated cooperating companion or a simulated defecting one, the fish behaved according to tit-for-tat strategy, supporting the hypothesis that cooperation can evolve among egoists.

Typically, sticklebacks operate in pairs. Individuals have partners with which they repeatedly perform pairwise predator inspection visits. Two reciprocal pairs per trial occur significantly more often than what was expected due to chance. These results provide further evidence for a tit-for-tat cooperation strategy in sticklebacks.

Stickleback behavior is often cited as an archetypal example of cooperative behavior during predator inspection. Fish from three sites differing in predation risk inspected a model predator in pairs and reciprocated both cooperative moves and defections by the partner, but not on every opportunity. Sticklebacks that originated in the two sites containing piscivorous fish were more likely to reciprocate following a cooperative move than following a defection. Individuals from higher-risk sites were generally more cooperative. Individuals accompanied by a model companion show reciprocal moves of cooperation and defection in response to the model's movements about a third of the time. Both examples of stickleback behavior demonstrate the elements of a strategy of cooperation that may resemble tit-for-tat.

Partner-dependence
The tit-for-tat cooperation strategy has been shown to be evident in sticklebacks. In addition, the size of a stickleback's partner fish may also be a factor in determining what a stickleback will do when both fish are faced with a predator. Two sticklebacks simultaneously presented to a rainbow trout, a predator much larger in size, will have differing risks of being attacked. Usually, the larger of the two sticklebacks has a higher risk of being attacked. Individual sticklebacks are more likely to move closer to a trout (or some other predator) when a larger potential partner moves close to the trout than when a smaller partner approaches the trout. Although both large and small partners behave similarly, a small partner's behavior affects the strategy of the test fish more than that of the large partner. Regardless of whether it is alone or with a partner that cooperates, a larger fish will approach a predator more closely than does a smaller fish. If a partner defects, then a stickleback's condition-factor (i.e. its ability to flee) determines how closely it approaches the predator rather than the stickleback's size. Both the strategy and reaction to different-sized partners seem to be dependent on whether the partner cooperates or defects.

Parasites

The three-spined stickleback is a secondary intermediate host for the hermaphroditic parasite Schistocephalus solidus, a tapeworm of fish and fish-eating birds. The tapeworm passes into sticklebacks through its first intermediate hosts, cyclopoid copepods, when these are eaten by the fish. The parasite matures into its third larval stage, the plerocercoid, in the abdomen of the stickleback. Infected sticklebacks are afterwards consumed by fish-eating birds, which serve as the tapeworm's definitive host.

Another common parasite of the three-spined stickleback is the microsporidian Glugea anomala. Naturally infections with G. anomala lose weight compared to uninfected individuals, but do not cause size differences between individuals. Glugea anomala also correlates behavioural changes, such as increased shoaling, increased sociability and activity, and reduced boldness. It is unknown whether these differences in behaviour are due to certain personality traits predisposing individuals to infections, or whether infections change behaviour.

Genetics
Three-spined sticklebacks have recently become a major research organism for evolutionary biologists trying to understand the genetic changes involved in adapting to new environments. The entire genome of a female fish from Bear Paw Lake in Alaska was recently sequenced by the Broad Institute and many other genetic resources are available. This population is under risk from the presence of introduced northern pike in a nearby lake. Three-spined sticklebacks are also used for researching sex-specific brain gene expression. Parents exposed to predator models produced offspring with different gene expressions compared to those that were not exposed to predators. Non-overlapping genes appear highly influenced by the sex of the parent, with genes being differentially expressed in offspring based on whether the male or female parent was exposed to predation.

Eco-evolutionary dynamics
Three-spined stickleback research has been central to the field of eco-evolutionary dynamics. Eco-evolutionary dynamics is an area of study investigating how ecological processes (e.g., population dynamics, community interactions, and nutrient cycling) affect how populations evolve, and in turn, how these patterns of evolution feed back to affect ecological processes. Importantly, these dynamics arise when substantial evolutionary change occurs on the same time scale as ecological change (i.e., less than 1,000 generations). Three-spined stickleback are particularly useful for studying eco-evolutionary dynamics because multiple populations have evolved rapidly and in predictable, repeated patterns after colonizing new environments. These repeated patterns of evolution allow scientists to assess whether the impacts of stickleback evolution on ecological processes are reproducible.

An eco-evolutionary framework has been used to explore multiple aspects of stickleback biology. Notably, this research has focused on how populations of three-spined stickleback have diverged to occupy different ecological niches (a process called adaptive radiation) and how sticklebacks have coevolved with their parasites.

Eco-evolutionary dynamics of adaptive radiation
Most eco-evolutionary dynamics research in sticklebacks has focused on how the adaptive radiation of different ecotypes affects ecological processes. Ecotypes represent genetically and morphologically recognizable populations occupying distinct ecological niches. In three-spined stickleback, divergent ecotypes are often found as sympatric (i.e., co-occurring) or parapatric (i.e., partially overlapping, but mostly isolated) species pairs, including benthic—limnetic pairs, freshwater—anadromous pairs, and lake—stream pairs. Pairs of stickleback ecotypes have diverged at time scales ranging from 10,000 years to only decades ago.

Different combinations of stickleback ecotypes affect ecosystem processes in different ways. For example, the combined presence of specialized benthic and limnetic sticklebacks has a different effect on the diversity and abundance of prey species compared to the presence of only a generalist ancestral stickleback ecotype. Notably, this effect appears to be driven by limnetic sticklebacks specializing on zooplankton prey, rather than by an increase in the number of co-occurring stickleback species alone. The impacts of ecotype specialization on prey communities can even affect the abundance of algae and cyanobacteria that do not directly interact with sticklebacks, along with aspects of the abiotic environment, such as the amount of ambient light available for photosynthesis and levels of dissolved oxygen, carbon, and phosphorus. These diverse changes in ecosystem processes can persist to affect natural selection on subsequent stickleback generations, potentially shaping how stickleback populations will evolve in the future. Because the presence of specialist verses generalist ecotypes can impact ecosystems in a way that, in turn, affects selection on future stickleback generations, the adaptive radiation of specialized ecotypes could drive eco-evolutionary feedback loops in natural populations.

Eco-evolutionary dynamics of host-parasite interactions
Sticklebacks have also been studied to investigate the eco-evolutionary dynamics of host-parasite coevolution. Three-spined sticklebacks can be hosts to a variety of parasites (e.g., Schistocephalus solidus, a common tapeworm of fish and fish-eating birds ). The diversity of parasite species within individual stickleback is influenced by an individual's dietary niche and immune response. This covariation between parasite infection and host traits is likely a consequence of eco-evolutionary feedback, whereby the evolution of dietary and parasite resistance traits in sticklebacks alters parasite reproduction and infection rates, which in turn affects parasite exposure and selection on parasite resistance in sticklebacks. These feedbacks can also extend beyond stickleback-parasite interactions to modify ecosystem processes. Specifically, differences in resistance and infection rates among stickleback ecotypes can alter how sticklebacks affect the abundance of prey species and levels of dissolved nutrients and oxygen. These ecosystem impacts can further affect selection on sticklebacks in subsequent generations, which suggests a complex feedback loop between the evolution of host-parasite interactions, community composition, and abiotic conditions.

Common methods
Many researchers have used mesocosm experiments to test how the adaptive radiation of stickleback ecotypes and stickleback-parasite interactions can impact ecological processes. In these experiments, researchers simulate the natural environments of sticklebacks in enclosed tanks, including natural plant and invertebrate communities and freshwater ecological zones. They then systematically manipulate an independent variable (e.g., which stickleback ecotypes were present or the presence of parasites), and measured differences in biotic and abiotic aspects of ecosystems among the different stickleback treatments. In some cases, researchers have then tested for potential feedback loops between ecotype evolution and ecological change by removing the adult stickleback from the mesocosms and replacing them with juveniles of different ecotypes. By doing so, the researchers could then measure how the effects of adult sticklebacks on their ecosystems influenced overall juvenile fitness (e.g., survival and growth rates) and differences in fitness between juveniles of different ecotypes.

title: Three-spined stickleback


text: Template:Trafalgar class submarine

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

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Talk:Earl Grey tea

External link
That 24health link seems placed there for advertising purposes. It links to a basic article on a site with 500 advertisements that ads nothing to the Wiki article, with speculative non-scientific information about Earl Grey as a folk cure. If anyone agrees, then there are two votes to ax it. I believe it also fails many accessibility guidelines (a requirement under Wiki guidelines for an external link) If there is any information of value on that page, it's brief enough that it should be double-checked, included, and cited -- but not listed as an external link.

Allergy
A comment about some people being allergic to bergamot perhaps? (Not that Wikipedia should be a medical reference, but it might be useful).

Captain Picard
How can any article on Earl Grey Tea not include it's greatest promotor: Captain Jean-Luc Picard of the starship Enterprise, who brought the popularity of the tea storming into the 20th century? To disregard him as a fictional character is tantamount to ignoring Paddington Bear's popularitisation of marmalade or the Earl of Sandwhich to the bread bracketed popular quick meal! 94.174.148.42 (talk) 19:34, 18 July 2023 (UTC)

 * To include this information, we would need some reliable secondary sources that demonstrate that this is notable and not just trivia. See WP:POPCULTURE for more info on that. Popcornfud (talk) 19:39, 18 July 2023 (UTC)
 * As someone currently drinking some Earl Grey, I lean towards inclusion. If my expertise in this leaf isn't enough, a few sources seem to support my position. Gizmodo is considered a generally reliable source–it is green-listed at Reliable sources/Perennial sources–and published this article on Picard's taste in 2020 (but there's no accounting for the article author's taste, I suppose). CNET published this article on Earl Grey's place on the final frontier in 2016; CNET pre-2020 was considered generally reliable, but this approbation was directed only towards its tech coverage. Per WP:VANITYFAIR, this article from 2020 seems to demonstrate that this information is at the very minimum publicly notable. If there wasn't a significant amount of reference to Picard and Earl Grey tea, I would agree that this would be stereotypical POPCULTURE material. However, I think we have enough. ~ Pbritti (talk) 20:10, 18 July 2023 (UTC)
 * The description for the image of the tea starting with tea, earl grey, hot, is more than adequate in my opinion. DETHREAPER (talk) 19:36, 21 July 2023 (UTC)

No evidence for health benefits
This edit was justified because there are no WP:MEDRS sources specifically identifying health benefits of consuming Earl Grey tea or more generally back tea. The previous version also contains weak sources – a previous (blacklisted) Healthline source, a spam website (Stylecraze), and a case study, which are far from sufficient to indicate any health benefit of bergamot oil.

On PubMed, there are no usable WP:MEDRS sources to support any health effects of the small amount of bergamot oil present in Earl Grey tea.

The edit was reverted, but I will return to the only concise statement we can make. The only alternative is to have no health section because the specific evidence for Earl Grey tea having health effects does not exist. Zefr (talk) 16:03, 27 July 2023 (UTC)
 * I agree with Zefr on this: we need exceptional sources to make exceptional claims. ~ Pbritti (talk) 16:55, 27 July 2023 (UTC)
 * The second paragraph had citation needed and I understand removal. Third paragraph also makes sense to remove. What was issue with first paragraph that was controversial? It makes same claim from black tea about polyphenols reputed health benefits, but researching being inconclusive, using the same PubMed source. The claim wasn't for bergamot oil, but for black tea since Earl Grey Tea is just black tea(usually) flavored with bergamot oil. WikiVirusC (talk) 17:25, 27 July 2023 (UTC)
 * The first paragraph contained no reliable sources specifically on the health effects of Earl Grey tea itself. The articles on the health effects of tea and black tea specifically show no MEDRS evidence for clear health benefits of drinking any type of tea.
 * In the edited version, the phrase "reputed to have cardiovascular, digestive, and cancer-preventitive benefits" cannot be supported with MEDRS sources, as it derives from folklore, alternative medicine or public misinformation. Zefr (talk) 18:37, 27 July 2023 (UTC)

title: Talk:Earl Grey tea


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User talk:Kunjan1029

thanks for correcting the typo on my userpage -- varunrebel no prob.. -- kunjan

Ahmedabad page
Hi. Glad you liked the images. Actually, I don't know anything about the town, but it was listed on Requested images. I just checked the foreign language links for Ahmedabad on Wikipedia and copied. Please feel free to improve the description. Happy editing -- Chris 73 | Talk 08:06, 16 Jul 2004 (UTC)

Edit attributions
Hi Kunjan. Edits from 208.190.203.161 have now been reattributed to you. Regards  — Kate Turner | Talk 07:26, 2004 Sep 4 (UTC)

India facts
I merely copied the facts from the India main page to this new page so keep the limit under 30kb. I believe most of the facts are true, but yes some may be construed as a POV unless someone adds a reference to the ambigious ones. ¶ ɳȉčḩåḽṗ| [[User talk:nichalp|✉]] 18:54, Oct 13, 2004 (UTC)

 * No, don't put it up for deletion. I believe the page will attract a lot of interest. Most are true to the best of my knowledge. I'll modify the headings of the unverified statements. ¶ɳȉčḩåḽṗ|[[User talk:nichalp|✉]] 19:07, Oct 14, 2004 (UTC)

Seeking you support
I am seeking your support and participation for starting the "Indian Collboration of the Week". Please enlist your support on the page Wikipedia_talk:Indian_wikipedians%27_notice_board if you would like to support. Thanks Arunram 08:17, 21 Jan 2005 (UTC)

 * Kunjan, you can vote for your collboration article at WP:INCOTW. Try it out. Arunram 19:57, 1 Feb 2005 (UTC)

Image:Dr.Rajendra.Prasad.jpg listed for deletion
An image or media file that you uploaded, Image:Dr.Rajendra.Prasad.jpg, has been listed at Images and media for deletion. Please look there to see why this is (you may have to search for the title of the image to find its entry), if you are interested in it not being deleted. Thank you. --Flominator 23:35, 3 March 2006 (UTC)

Deskstation
Err, I wasn't the person who started the Deskstation article. I think you want Ryanaxp. Anyways, I'm pretty sure Deskstation used industry-standard connectors. Maybe just something so old that you're not familiar with? Perhaps SCSI disk drives? Also, your webpage needs additional personal info to send email, stuff I prefer not to give out. Dyl 04:44, 7 September 2006 (UTC)
 * Thanks a lot for your help! its got scsi drives. but not sure what is the protocol they use. coz all that this tower has on the back is 2 db9 ports! http://kunjan.net/contactme/ this page? --kunjan1029 06:15, 8 September 2006 (UTC)

Ahoy hoy, Ryanaxp here, responding to your query about DeskStation hardware. Unfortunately, I never owned nor even saw first-hand any DeskStation equipment, although I learned about them during my brief period of fascination with all things MIPS some 8 or 9 years ago. As Dyl mentioned above, and as you confirmed, the disks are SCSI drives (almost certainly with the old bog-standard 50pin ribbon connectors)--so it should be a simple matter to just hook them up to a PC with a SCSI adapter installed. If you can't find one, try eBay for an Adaptec 2940 (just make sure it has a 50-pin connector) and slap it into any PC running Linux or Windows XP. The filesystem on the disks is most likely NTFS or FAT, either of which should be recognized instantly by Windows (or with a slight amount of effor, Linux). Other than that, I'm afraid I don't really know anything more about the DeskStation machines beyond what's in the wikipedia article. Good luck. --Ryanaxp 15:07, 8 September 2006 (UTC)
 * Thanks a lot! that should help me out quite a bit! --kunjan1029 08:07, 13 September 2006 (UTC)

Orphaned non-free image File:Dr.Rajendra.Prasad.jpg
 Thanks for uploading File:Dr.Rajendra.Prasad.jpg. The image description page currently specifies that the image is non-free and may only be used on Wikipedia under a claim of fair use. However, the image is currently not used in any articles on Wikipedia. If the image was previously in an article, please go to the article and see why it was removed. You may add it back if you think that that will be useful. However, please note that images for which a replacement could be created are not acceptable for use on Wikipedia (see our policy for non-free media).

Note that any non-free images not used in any articles will be deleted after seven days, as described in the criteria for speedy deletion. Thank you. Skier Dude2 (talk) 05:27, 15 June 2011 (UTC)

Talk:Ahmedabad/GA2
Hi. I've opened a GAR on the Ahmedabad article for which you are a main contributor. I have concerns that it does not quite meet current GA criteria regarding sourcing and MoS. Following the guidelines at Good article reassessment, I'm letting you know in case you're interested in helping to resolve the concerns, though you are under no obligation to do anything. See Talk:Ahmedabad/GA2 for more details.  SilkTork  ✔Tea time  14:37, 6 May 2014 (UTC)

title: User talk:Kunjan1029


text:
HMS Trafalgar (S107)

HMS Trafalgar is a decommissioned Trafalgar-class submarine of the Royal Navy. Unlike the rest of the Trafalgar-class boats that followed, she was not launched with a pump-jet propulsion system, but with a conventional 7-bladed propeller. Trafalgar was the fifth vessel of the Royal Navy to bear the name, after the 1805 Battle of Trafalgar.

Operational history
In 2012 a Royal Navy submariner was jailed for 8 years for trying "to pass secrets to the Russians that could have undermined Britain's national security"; one element of this was information on "a secret operation undertaken by HMS Trafalgar.

Combat history
After Operation Veritas, the attack on Al-Qaeda and Taliban forces following the September 11 attacks in the United States, Trafalgar entered Plymouth Sound flying the Jolly Roger on 1 March 2002. She was welcomed back by Admiral Sir Alan West, Commander-in-Chief of the fleet and it emerged she was the first Royal Navy submarine to launch Tomahawk cruise missiles against Afghanistan.

Grounding incidents
In July 1996, Trafalgar grounded near the Isle of Skye in Scotland.

In November 2002, Trafalgar again ran aground close to the Isle of Skye, causing £5 million worth of damage to her hull and injuring three sailors. She was travelling 50 metres below the surface at more than 14 knots when Lieutenant-Commander Tim Green, a student in the "Perisher" course for new submarine commanders, ordered a course change that took her onto the rocks at Fladda-chuain, a small but well-charted islet. Commander Robert Fancy, responsible for navigation, and Commander Ian McGhie, an instructor, both pleaded guilty at court-martial to contributing to the accident. On 9 March 2004 the court reprimanded both for negligence. Green was not prosecuted, but received an administrative censure.

In May 2008 it was reported that the crash was caused by the chart being used in the exercise being covered with tracing paper, to prevent students marking it.

Decommissioning
Trafalgar was decommissioned on 4 December 2009 at Devonport.

title: HMS Trafalgar (S107)


text:
HMS Turbulent (S87)

HMS Turbulent is a retired Trafalgar-class submarine of the Royal Navy and the second vessel of her class. Turbulent was the fifth vessel, and second submarine, of the Royal Navy to bear this name. She was built by Vickers Shipbuilding, Barrow-in-Furness, and based at HMNB Devonport. She was commissioned in 1984 and decommissioned in July 2012. She was stripped of equipment and now awaits dismantling in number 3 Basin at Devonport.

Originally intended to hunt down Soviet missile submarines, after the end of the Cold War Turbulent spent more time on intelligence gathering missions and landing commando units, as well as firing Tomahawk missiles during the 2003 Iraq war.

Operational history
Turbulent undertook a modernisation program and first nuclear refuelling in 1997.

2003 War in Iraq
Turbulent took part in the 2003 invasion of Iraq, firing thirty Tomahawk cruise missiles during the campaign. On 16 April 2003 she was the first Royal Navy vessel to return home from the war. Turbulent arrived in Plymouth flying the Jolly Roger, a tradition in the Royal Navy signifying having fired weapons in anger.

2011 Military Intervention in Libya
Turbulent left Devonport in February 2011 for a 268-day deployment East of Suez, which was due to be her final before decommissioning. The deployment saw her operating in the Gulf of Sidra relieving HMS Triumph as part of the British contribution to the Libya intervention. She was then herself relieved by Triumph, before heading through the Suez Canal in June to take up patrol in the Indian Ocean. The boat called into the port of Fujairah, where she rendezvoused with the support ship RFA Diligence. Turbulent returned to Devonport on 14 December 2011, having spent 190 days of her 267-day deployment underwater and travelling more than 38,000 miles A documentary called Royal Navy Submarine Mission on Channel 5 featured Turbulent during this 2011 deployment.

During this deployment, just after sailing from Fujairah on 26 May, Turbulent suffered a catastrophic failure of her air-conditioning systems, while on the surface. Internal temperatures quickly rose to 60 °C with 100% humidity, and caused 26 casualties, mainly from heat exhaustion, eight of which were life-threatening. With ambient temperatures in the Indian Ocean at 42 °C, surface ventilation was ineffective and the submarine was only effectively cooled by diving to 200 metres. The cause was later found to be blockage of water inlet pipes by barnacles during an extended stay at Fujairah. The incident was only made public in 2014.

2012 South Atlantic deployment
Turbulent was scheduled to be decommissioned at the end of 2011. In February 2012 it was reported that either Turbulent or HMS Tireless was being deployed to the Falkland Islands amid increasing tension between Argentina and the United Kingdom over sovereignty of the islands. Commander Nick Wheeler took command in December 2011 until decommissioning on 14 July 2012. She is now being stripped of equipment and will await dismantling in 3 Basin at Devonport Dockyard, Plymouth.

title: HMS Turbulent (S87)


text:
HMS Tireless (S88)

HMS Tireless was the third Trafalgar-class submarine nuclear submarine of the Royal Navy. Tireless is the second submarine of the Royal Navy to bear this name. Launched in March 1984, Tireless was sponsored by Sue Squires, wife of Admiral 'Tubby' Squires, and commissioned in October 1985.

During the Cold War Tireless was primarily involved in anti-submarine warfare patrols in the Atlantic Ocean. After the Cold War, Tireless was deployed around the world, including to the Arctic Ocean, Mediterranean Sea and Pacific Ocean. At the end of its career, Tireless was involved in the search for the missing airliner, Malaysia Airlines Flight 370. The vessel experienced a number of serious accidents during its operational life.

Tireless had been scheduled for retirement during 2013, but its service was extended until eventual decommissioning on 19 June 2014. Tireless was replaced on active duty by HMS Artful.

Operational history
From commissioning in 1985, Tireless completed numerous exercises and visits around the world, including a trip to the Arctic in 1991, before entering a refit in early 1996, returning to sea in 1999.

Primary coolant leak
In May 2000, Tireless developed a serious leak in the nuclear reactor primary cooling circuit, although there was no leak of radioactive material. The nuclear propulsion system was shut down and using backup diesel power Tireless made way to Gibraltar. The damage was found to be more extensive than first thought, and the boat remained there pending repairs. This created diplomatic tension between Spain and Britain, until the submarine departed on 7 May 2001 after almost a year of extensive repairwork. During that year, all Trafalgar-class submarines were inspected for similar problems.

Collision with iceberg
On 13 May 2003, while on exercise in the Arctic and travelling at a depth of 60 metres, Tireless collided with an iceberg. There was no prior warning of the impending collision from passive sonar or other onboard sensors. The submarine's bow was forced down nine degrees and the vessel subsequently broke free of the iceberg at a depth of 78 metres. Some damage was sustained to the upper section of the boat. Before the incident, the Royal Navy had not conducted under-ice operations since 1996.

On 19 April 2004, Tireless and USS Hampton (SSN-767) rendezvoused under the Arctic ice and surfaced together at the North Pole.

Tireless again angered Spain in 2004 when the boat put into Gibraltar from 9 to 15 July for what was explained as "technical reasons." Britain assured Spain that the port call was unrelated to the British celebrations, on 21 July, of the 300th anniversary of Spain handing over Gibraltar to Britain.

March 2007 explosion
In 2007 Tireless ventured to the North Pole with USS Alexandria (SSN-757) to participate in the Applied Physics Laboratory Ice Station (APLIS). On 21 March, two Tireless crew members, Leading Weapons Engineer Paul McCann and Weapons Engineer 2 Anthony Huntrod (Weapons Submariner) were killed in an explosion on board, apparently caused by an oxygen generator candle in the forward section of the submarine. The boat was in service near the North Pole under ICEX-07 along with the USS Alexandria and had to make an emergency surface through the ice cap. A third crewmember suffered "non life-threatening" injuries and was airlifted to a military hospital at Elmendorf Air Force Base near Anchorage, Alaska.

According to the Royal Navy, the accident did not affect the submarine's nuclear reactor, and the boat sustained only superficial damage. Part of the exercise was being used to measure ice thickness by using sonar. The film Stargate: Continuum—which was filming on the ice and in the Alexandria during the exercise—was dedicated to McCann and Huntrod.

2010-2011 deployment
From 9 July 2010 to 12 May 2011, Tireless undertook a ten-month deployment, spending 253 days at sea, the longest conducted by a Royal Navy submarine in ten years. During the deployment the boat passed through the Suez Canal for the first time, provided protection for the French aircraft carrier Charles de Gaulle launching aircraft over Afghanistan, and called into the ports of Fujairah in the United Arab Emirates, Goa in India and Souda Bay in Crete. Tireless was also involved in a multi-nation anti-submarine exercise in the Gulf of Oman which saw the Australian frigate HMAS Melbourne and the French frigate FS Dupleix attempt to locate the submarine.

2012 South Atlantic deployment
In February 2012, it was reported that either Tireless or HMS Turbulent was being deployed to the Falkland Islands amid increasing tension between Argentina and the United Kingdom over sovereignty of the islands.

However HMS Tireless surfaced in Southampton in March, conducting towed array sonar calibration and testing in the Bay of Biscay before returning to Devonport.

2013 Coolant leak
In early 2013 Tireless experienced a "small coolant leak that was contained within the sealed reactor compartment", requiring a return to HMNB Devonport for repair.

2013 Mediterranean deployment
Tireless was spotted off the Rock of Gibraltar amidst the tensions between Spain and the UK over the disputed territory of Gibraltar. It was suggested that this SSN could be a key vessel used to strike Syria if military action occurred.

2014 Indian Ocean search - Malaysian Airlines flight MH370
On 1 April 2014, Tireless arrived in the southern Indian Ocean to join the search for a missing Malaysian airliner, where its sophisticated underwater listening equipment was used in an unsuccessful attempt to detect the underwater locator beacon of the aircraft's flight recorders.

Final return to Plymouth
On 1 June 2014 Tireless returned to Plymouth for the last time before decommissioning, and was formally decommissioned on 19 June.

Tireless' final operations saw visits to Gibraltar, Crete, India, Jordan, the UAE and Australia.

Tireless was moved in 2020 to a basin within Devonport dockyard often referred to as “the graveyard”.

title: HMS Tireless (S88)


text:
Raoul Barré

Vital Achille Raoul Barré (January 29, 1874 – May 21, 1932) was a Canadian cartoonist, animator of the silent film era, and painter. Initially known as a political cartoonist, he originated the French Canadian comic strip, then crossed over into animated film and started his own studio, a pioneering effort. As a painter, he is considered an Impressionist, evoking atmosphere and light with visible, choppy strokes of paint, whose paintings are in the Musée national des beaux-arts du Québec.

Personal history and career
Barré was born in Montreal, Quebec, the only artistic child (out of twelve) of a wine merchants and importers. He studied art at the Académie Julian, starting in 1896, and remained there for two years also known as a political cartoonist—he was a loud critic of the unjust trials of Captain Alfred Dreyfus. One of Barré's opponents in the war of words and cartoons was Émile Cohl, writing anonymously. On returning to Canada in 1898, he gave birth to the French Canadian comic strip. It was not until 1913 that Barré succeeded in syndicating a newspaper strip in the U.S—Noahzark Hotel, a Sunday strip which was distributed by the McClure Syndicate for 11 months. Barré elected not to take credit on the strip, but rather signed it VARB, his initials (Vitale Achille Raoul Barré).

Barré moved to New York City in the United States in 1903. In 1912, Barré saw an animated film that inspired him to go into the industry (perhaps Winsor McCay's "How a Mosquito Operates"). He picked Edison Studios to produce his cartoons and while visiting the studio, met Bill Nolan, a live-action shorts producer who became his business and artistic partner. The two worked together for a year putting out animated and live-action commercials for various companies (quite possibly the first ever use of animation for advertising). It was during this period that the two worked out a system for animating which was radically different from that practiced by anyone else at the time.

Various animators had come up with different methods to keep their drawings lined up, but none of them worked very well. Barré and Nolan's solution was to punch two holes at the bottom of all of their sheets and pass them through two pegs glued to the animation table. This peg system is still in practice today. The system they used for animation, on the other hand, was a dead end precisely because it produced registration problems the peg system couldn't always fix. The basis of this "slash system" was to tear away the paper being drawn on to show the change underneath. For example, if a character was to move his arm, the first drawing would consist of character and background, then the arm would be carefully torn out to reveal the next sheet down and a new arm was drawn on the new paper revealed. The slash system lasted through the 1920s at various studios before being replaced by Earl Hurd's cel animation system.

By 1914, Barré and Nolan felt confident enough to start their own studio, totally independent of Edison and dedicated 100% to animation. This Barré-Nolan Studio was probably the first of its kind (although Bray Productions also had a good claim to the title). The main title produced by the new studio was a series of inserts for the mostly live-action Animated Grouch Chaser series, distributed by Edison.

In 1916, William Randolph Hearst, multi-millionaire and newspaper magnate, started a rival animation studio called International Film Service and hired most of Barré's animators, including Bill Nolan, by paying them more money than Barré could provide. Barré was reduced to being a contractor for IFS, animating the series Phables. After seven cartoons, he quit.

Another man who had stood up to Hearst was Bud Fisher, who had the courts uphold his copyright ownership to his Mutt and Jeff comic strip, which had been printed by Hearst newspapers for nine years. Fisher had turned to independent animator Charles Bowers to turn his strip into a cartoon, but Bowers did not have the facilities to pull this off. Barré had the facilities, but not the men. A partnership was born in the form of Barré-Bowers Studios situated in the Fordham section of The Bronx. Barré did what he could to improve the quality of the animation in his films, investing some of the profits into art classes for the animators (in anticipation of Walt Disney providing such training to his own employees during the 1930s).

Mutt and Jeff was a strong money-maker for Barré, Bowers, and Fisher, but Barré began to get tired of it all as the years passed, due to personality conflicts with both partners. Barré retired from animation in 1919, amid rumors of a nervous breakdown. He settled into his home in Glen Cove, Long Island, and started selling his oil paintings to the public, as well as some commercial poster work. In the meantime, the surviving partners had a falling out and by 1926 Mutt and Jeff was finished as a film animation property.

In 1925, Barré came to long for the world of animation again, as a replacement for Bill Nolan since he left for the Krazy Kat cartoons. He got what he wanted with the position of "guest animator" for Pat Sullivan Productions working on Felix the Cat. The cartoons Barré created for Sullivan are considered the best he ever did, as well as the best Felix cartoons ever made (the chicken antagonist in such cartoons as "Felix Dines and Pines" and "The Oily Bird" was drawn entirely by Barré). Raoul Barré retired from animation the second time in 1927, this time on a high note. Barré spent the last few years of his life drawing oil paintings and political cartoons, while starting his own art school.

He died in Montreal on May 21, 1932, of cancer and was buried in the city's Notre Dame des Neiges Cemetery.

title: Raoul Barré


text:
HMS Torbay (S90)

HMS Torbay is a decommissioned Trafalgar-class submarine nuclear submarine of the Royal Navy and the fourth vessel of her class. Torbay was the fifth vessel and the second submarine of the Royal Navy to be named after Torbay in Devon, England. The first vessel was the 80-gun second rate HMS Torbay launched in 1693.

She was the first vessel to be fitted with the new command system SMCS-NG.

Torbay was scheduled to be decommissioned in 2015, to be replaced by one of the new Astute-class submarines. she was undergoing extended maintenance and upgrades. The work allowed for a two-year life extension beyond the previously-planned decommissioning date. On 6 June 2017, she entered Gibraltar Naval Base flying her paying-off pennant and, on Friday 14 July 2017, the vessel was decommissioned in Devonport.

Operational history
Torbay completed a refuel and modernisation process in February 2001.

In early 2006, Torbay was the participant in an experiment in the use of colour schemes to reduce the visibility of submarines from the air. The standard black paint of Royal Navy submarines was replaced by a carefully selected shade of blue. This was the result of research that found that black was the worst possible colour for a submarine attempting to avoid detection from the air. This change is in part the result of the changing nature of Royal Navy commitments since the end of the Cold War, with Navy operations moving from the murky waters of the North Atlantic to the clearer waters of the Arabian Sea and the Indian Ocean.

In November 2010, it was reported in Hansard that Torbay had run aground in the Eastern Mediterranean in April 2009.

In May 2011, she took part in Exercise Saxon Warrior in the Western Approaches. The exercise included the aircraft carrier USS George H.W. Bush (CVN-77), HMS Dauntless, HMS Westminster, and a number of other vessels and culminated in a "Thursday War".

In late 2011 she entered a revalidation and assisted maintenance period (RAMP) at Devonport Royal Dockyard. This includes communications upgrades with installation of the Cromwell radio antenna to enhance internal communications and the ship alongside upgrade, plus inspection of the hull and reactor, an overhaul of one of the reactor coolers and upgrades to many other systems. the RAMP was 85% complete, with a return to service originally planned for summer 2013.

In 2013, there was a fire on board.

She made her final entry to Devonport on 19 June 2017 prior to her formal decommissioning parade on 14 July 2017.

title: HMS Torbay (S90)


text:
HMS Trenchant (S91)

HMS Trenchant was a Trafalgar-class submarine nuclear-powered fleet submarine of the Royal Navy built by Vickers Shipbuilding, Barrow-in-Furness. Trenchant was based at HMNB Devonport. She was the third vessel and the second submarine of the Royal Navy to be named for the characteristic of vigour and incisiveness.

The submarine was ordered on 22 March 1983. She was laid down by Vickers Shipbuilding on 28 October 1985, and was launched on 3 November 1986 in the presence of Vice Admiral Sir Arthur Hezlet, who had commanded the World War II T-class submarine HMS Trenchant (P331). She was commissioned into the Royal Navy on 14 January 1989.

Following the Integrated Review of 2020, Trenchant left active service in 2021 and formally decommissioned in May 2022.

1990–1999
On 22 November 1990, the nets of the trawler FV Antares were snagged by Trenchant in the Bute Sound in Scotland. At the time the submarine was conducting a 'Perisher' Submarine Command Course exercise in company with the frigate HMS Charybdis (F75). Antares was pulled under with the loss of all four members of the crew. A subsequent Marine Accident Investigation found that the accident had been caused by "a partial breakdown in both the structure and the standards of watchkeeping on board Trenchant".

In July 1997, the submarine ran aground off the western coast of Australia. While approaching Fremantle, Western Australia, the submarine remained at a depth of 200 m and grounded when she made contact with the continental shelf, coming to rest on a sloping patch of seafloor. Trenchant was able to free herself, and an inspection by divers reported no significant damage.

Trenchant tested the non-hull-penetrating optronic mast in 1998. She also trialled a camouflage paint scheme comprising jagged shapes of various colours, including pale blue.

2000–2022
On 21 June 2007, the submarine became the first Royal Navy vessel to fire the new Block IV Tomahawk cruise missile in a live-firing trial in the Gulf of Mexico off the United States coast.

In late 2009, Trenchant entered the Devonport submarine refit complex to undertake a 2-year refit and upgrade programme. Upon completion of the programme, the submarine underwent a rededication service on 6 June 2011 to welcome the boat back to active service.

On 22 May 2013, Trenchant completed the longest patrol ever carried out by a Royal Navy SSN. The patrol lasted 335 days (11 months) during which the submarine sailed 38,800 nmi. During this time the vessel visited six different ports: Fujairah, UAE; the British Indian Ocean Territory – Diego Garcia; the Kingdom of Bahrain; Aqaba, Jordan; Souda Bay, Crete; and Gibraltar.

Following a maintenance period involving a weapon and sensors upgrade, Trenchant returned to service in August 2016.

In March 2018, Trenchant, along with the American submarines USS Connecticut (SSN-22) and USS Hartford (SSN-768), participated in ICEX 2018, surfacing through the Arctic ice. This was the first time a Royal Navy submarine participated in ICEX since 2007.

In April 2020 a Royal Navy investigation was opened into videos of sailors having a party while under lockdown. The submarine had returned to Devonport for repairs and the crew were required to stay on board in isolation while repairs were completed because of COVID-19 restrictions. It was confirmed that some sailors were drinking alcohol and it was reported that the captain had approved the party despite being advised that it might be inappropriate. The captain was sent home and later relieved of his command, and moved to another role within the Navy.

Trenchant's final four-month deployment in the Atlantic was filmed for a Channel 5 television documentary called Submarine: Life Beneath the Waves, which was first shown in the United Kingdom in September 2021. On 25 March 2021 she sailed into Plymouth for the last time, flying her decommissioning pennant, ahead of decommissioning later.

Trenchant was decommissioned in a joint ceremony with HMS Talent (S92) on 20 May 2022 in the presence of the Princess Royal.

Affiliations
Trenchant is affiliated with the following military and civilian organisations, bodies & individuals:

 * Sea Cadet unit TS St David's
 * Sea Cadet unit TS Echo (Llanelli)
 * Town of Llanelli
 * Lady Meriel Hunt (sponsor)

title: HMS Trenchant (S91)


text:
HMS Talent (S92)

HMS Talent is the sixth of seven Trafalgar-class submarine nuclear submarines operated by the Royal Navy from 1990 until 2022. It was built at Barrow-in-Furness.

Name
Talent is the third submarine of the Royal Navy to bear the name. The first was a T-class submarine that was transferred to the Royal Netherlands Navy as HNLMS Zwaardvisch (P322) before launching in 1943. The second, was also a T-class submarine, launched in 1945 and operated by the Royal Navy until 1966.

Operational history
Talent was launched by The Princess Royal in April 1988, and commissioned in May 1990.

Talent entered HMNB Devonport, its homeport, for a refit, rejoining the active fleet in March 2007 following a £386 million upgrade. This included a new reactor core, and updated sonar suite: Sonar 2076.

In 2009, Talent suffered loss of primary and alternative power supplies to its nuclear reactors while in dock.

On 6 August 2013, Talent returned to Plymouth after a 3-month deployment. In October 2013, the submarine conducted an anti-submarine exercise with HMS Dragon (D35), USS Gravely (DDG-107), USS Stout (DDG-55) and USS Barry (DDG-52).

In April 2015, it was reported that Talent had struck ice at some point in 2014 while tracking Russian vessels.

Talent moved from Devonport to HMNB Clyde in July 2019.

Although originally scheduled for decommissioning in 2021, the slow delivery of the Astute-class boats meant that Talent was retained in service for at least an additional 12 months, with a planned out of service date extended to the end of 2022.

Under the terms of the 2021 Integrated Review, Talent was scheduled to be decommissioned by the end of 2022, to be replaced by HMS Anson (S124), the fifth Astute-class submarine. In April 2022, it was reported that Talent was being prepared for disposal and the submarine was decommissioned in a joint ceremony with HMS Trenchant (S91) on 20 May 2022, in the presence of the Princess Royal.

Affiliations
The boat was affiliated with the town of Shrewsbury in Shropshire, and while commissioned, its crew enjoyed Freedom of the Town.

The submarine's sponsor was the Princess Royal, who presided over its launch in 1988 and its decommissioning ceremony in 2022.

title: HMS Talent (S92)


text:
Nd:YAG laser

Nd:YAG (neodymium-doped yttrium aluminum garnet; Nd:Y3Al5O12) is a crystal that is used as a lasing medium for solid-state lasers. The dopant, neodymium in the +3 oxidation state, Nd(III), typically replaces a small fraction (1%) of the yttrium ions in the host crystal structure of the yttrium aluminum garnet (YAG), since the two ions are of similar size. It is the neodymium ion which provides the lasing activity in the crystal, in the same fashion as red chromium ion in ruby lasers.

Laser operation of Nd:YAG was first demonstrated by J.E. Geusic et al. at Bell Laboratories in 1964.

Technology
Nd:YAG lasers are optically pumped using a flashtube or laser diodes. These are one of the most common types of laser, and are used for many different applications. Nd:YAG lasers typically emit light with a wavelength of 1064 nm, in the infrared. However, there are also transitions near 946, 1120, 1320, and 1440 nm. Nd:YAG lasers operate in both pulsed and continuous mode. Pulsed Nd:YAG lasers are typically operated in the so-called Q-switching mode: An optical switch is inserted in the laser cavity waiting for a maximum population inversion in the neodymium ions before it opens. Then the light wave can run through the cavity, depopulating the excited laser medium at maximum population inversion. In this Q-switched mode, output powers of 250 megawatts and pulse durations of 10 to 25 nanoseconds have been achieved. The high-intensity pulses may be efficiently frequency doubled to generate laser light at 532 nm, or higher harmonics at 355, 266 and 213 nm.

Nd:YAG absorbs mostly in the bands between 730–760 nm and 790–820 nm. At low current densities krypton flashlamps have higher output in those bands than do the more common xenon lamps, which produce more light at around 900 nm. The former are therefore more efficient for pumping Nd:YAG lasers.

The amount of the neodymium dopant in the material varies according to its use. For continuous wave output, the doping is significantly lower than for pulsed lasers. The lightly doped CW rods can be optically distinguished by being less colored, almost white, while higher-doped rods are pink-purplish.

Other common host materials for neodymium are: YLF (yttrium lithium fluoride, 1047 and 1053 nm), YVO4 (yttrium orthovanadate, 1064 nm), and glass. A particular host material is chosen in order to obtain a desired combination of optical, mechanical, and thermal properties. Nd:YAG lasers and variants are pumped either by flashtubes, continuous gas discharge lamps, or near-infrared laser diodes (DPSS lasers). Prestabilized laser (PSL) types of Nd:YAG lasers have proved to be particularly useful in providing the main beams for gravitational wave interferometers such as LIGO, VIRGO, GEO600 and TAMA.

Medicine
Nd:YAG lasers are used in ophthalmology to correct posterior capsular opacification, after cataract surgery, for peripheral iridotomy in patients with chronic and acute angle-closure glaucoma, where it has largely superseded surgical iridectomy, for the treatment of vitreous eye floaters, for pan-retinal photocoagulation in the treatment of proliferative diabetic retinopathy, and to damage the retina in ophthalmology animal research.

Nd:YAG lasers emitting light at 1064 nm have been the most widely used laser for laser-induced thermotherapy, in which benign or malignant lesions in various organs are ablated by the beam.

In oncology, Nd:YAG lasers can be used to remove skin cancers. They are also used to reduce benign thyroid nodules, and to destroy primary and secondary malignant liver lesions.

To treat benign prostatic hyperplasia (BPH), Nd:YAG lasers can be used for laser prostate surgery—a form of transurethral resection of the prostate.

These lasers are also used extensively in the field of cosmetic medicine for laser hair removal and the treatment of minor vascular defects such as spider veins on the face and legs. Nd:YAG lasers are also used to treat venous lake lip lesions. Recently Nd:YAG lasers have been used for treating dissecting cellulitis of the scalp, a rare skin disease.

Using hysteroscopy the Nd:YAG laser has been used for removal of uterine septa within the inside of the uterus.

In podiatry, the Nd:YAG laser is being used to treat onychomycosis, which is fungus infection of the toenail. The merits of laser treatment of these infections are not yet clear, and research is being done to establish effectiveness.

Dentistry
Nd:YAG dental lasers have been used for the removal of dental caries as an alternative to drill therapy, although evidence supporting its use is of low quality. They have also been used for soft tissue surgeries in the oral cavity, such as gingivectomy, periodontal sulcular debridement, LANAP, and pulpotomy. Nd:YAG dental lasers have also been shown to be effective at treating and preventing dental hypersensitivity, as an adjunct for periodontal instrumentation, and for the treatment of recurrent aphthous stomatitis.

Manufacturing
Nd:YAG lasers are used in manufacturing for engraving, etching, or marking a variety of metals and plastics, or for metal surface enhancement processes like laser peening. They are extensively used in manufacturing for cutting and welding steel, semiconductors and various alloys. For automotive applications (cutting and welding steel) the power levels are typically 1–5 kW. Super alloy drilling (for gas turbine parts) typically uses pulsed Nd:YAG lasers (millisecond pulses, not Q-switched). Nd:YAG lasers are also employed to make subsurface markings in transparent materials such as glass or acrylic glass and in white and transparent polycarbonate for identity documents. Lasers of up to 2 kW are used for selective laser melting of metals in additive layered manufacturing. In aerospace applications, they can be used to drill cooling holes for enhanced air flow/heat exhaust efficiency.

Nd:YAG lasers are also used in the non-conventional rapid prototyping process laser engineered net shaping (LENS).

Laser peening typically uses a high energy (10 to 40 joule) 10 to 30 nanosecond pulse. The laser beam is focused down to a few millimeters in diameter to deposit gigawatts of power on the surface of a part. Laser peening is unlike other manufacturing processes in that it neither heats nor adds material; it is a mechanical process of cold working the metallic component to impart compressive residual stresses. Laser peening is widely used in gas-fired turbine engines in both aerospace and power generation to increase strength and improve resistance to damage and metal fatigue.

Fluid dynamics
Nd:YAG lasers can be used for flow visualization techniques in fluid dynamics (for example particle image velocimetry or laser-induced fluorescence).

Biophysics
Nd:YAG lasers are frequently used to build optical tweezers for biological applications. This is because Nd:YAG lasers mostly emit at a wavelength of 1064 nm. Biological samples have a low absorption coefficient at this wavelength, as biological samples are usually mostly made up of water. As such, using an Nd:YAG laser minimizes the damage to the biological sample being studied.

Automotive
Researchers from Japan's National Institutes of Natural Sciences are developing laser igniters that use YAG chips to ignite fuel in an engine, in place of a spark plug. The lasers use several 800 picosecond long pulses to ignite the fuel, producing faster and more uniform ignition. The researchers say that such igniters could yield better performance and fuel economy, with fewer harmful emissions.

Military
The Nd:YAG laser is the most common laser used in laser designators and laser rangefinders.

During the Iran–Iraq War, Iranian soldiers suffered more than 4000 cases of laser eye injury, caused by a variety of Iraqi sources including tank rangefinders. The 1064 nm wavelength of Nd:YAG is thought to be particularly dangerous, as it is invisible and initial exposure is painless.

The Chinese ZM-87 blinding laser weapon uses a laser of this type, though only 22 have been produced due to their prohibition by the Convention on Certain Conventional Weapons. North Korea is reported to have used one of these weapons against American helicopters in 2003.

Cavity ring-down spectroscopy (CRDS)
The Nd:YAG may be used in the application of cavity ring-down spectroscopy, which is used to measure the concentration of some light-absorbing substance.

Laser-induced breakdown spectroscopy (LIBS)
A range of Nd:YAG lasers are used in analysis of elements in the periodic table. Though the application by itself is fairly new with respect to conventional methods such as XRF or ICP, it has proven to be less time consuming and a cheaper option to test element concentrations. A high-power Nd:YAG laser is focused onto the sample surface to produce plasma. Light from the plasma is captured by spectrometers and the characteristic spectra of each element can be identified, allowing concentrations of elements in the sample to be measured.

Laser pumping
Nd:YAG lasers, mainly via their second and third harmonics, are widely used to excite dye lasers either in the liquid or solid state. They are also used as pump sources for vibronically broadened solid-state lasers such as Cr4+:YAG or via the second harmonic for pumping Ti:sapphire lasers.

Additional frequencies
For many applications, the infrared light is frequency-doubled or -tripled using nonlinear optical materials such as lithium triborate to obtain visible (532 nm, green) or ultraviolet light. Cesium lithium borate generates the 4th and 5th harmonics of the Nd:YAG 1064 nm fundamental wavelength. A green laser pointer is a frequency doubled Nd:YVO4 diode-pumped solid state laser (DPSS laser). Nd:YAG can be also made to lase at its non-principal wavelength. The line at 946 nm is typically employed in "blue laser pointer" DPSS lasers, where it is doubled to 473 nm.

Properties of YAG crystal

 * Formula: Y3Al5O12
 * Molecular weight: 596.7
 * Crystal structure: Cubic
 * Hardness: 8–8.5 (Mohs)
 * Melting point: 1970 °C (3540 °F)
 * Density: 4.55 g/cm3

Properties of Nd:YAG @ 25 °C (with 1% Nd doping)

 * Formula: Y2.97Nd0.03Al5O12
 * Weight of Nd: 0.725%
 * Atoms of Nd per unit volume: 1.38×1020 /cm3
 * Charge state of Nd: 3+
 * Emission wavelength: 1064 nm
 * Transition: 4F3/2 → 4I11/2
 * Duration of fluorescence: 230 μs
 * Thermal conductivity: 0.14 W·cm−1·K−1
 * Specific heat capacity: 0.59 J·g−1·K−1
 * Thermal expansion: 6.9×10−6 K−1
 * dn/dT: 7.3×10−6 K−1
 * Young's modulus: 3.17×104 K·g/mm−2
 * Poisson's ratio: 0.25
 * Resistance to thermal shock: 790 W·m−1

title: Nd:YAG laser


text:
Focal point

Focal point may refer to:

 * Focus (optics)
 * Focus (geometry)
 * Conjugate points, also called focal points
 * Focal point (game theory)
 * Unicom Focal Point, a portfolio management software tool
 * Focal point review, a human resources process for employee evaluation
 * Focal Point (album), a 1976 studio album by McCoy Tyner
 * "Focal Point: Mark of the Leaf", a Naruto episode

title: Focal point