How the seahorse might have got its shape

Posted On Aug 31 2019 by

first_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. © 2010 PhysOrg.com More information: An adaptive explanation for the horse-like shape of seahorses, Nature Communications 2, Article number: 164 doi:10.1038/ncomms1168 Play Slow-motion replays of high-speed video recordings of the capture of copepods or mysid shrimp by, respectively, pipefish Syngnathus leptorhynchus, Doryrhamphus dactyliophorus, D. melanopleura, and Corythoichthys intestinalis and seahorses Hippocampus breviceps, H. abdominalis and H. reidi. Movie clips are slowed down 66 times, except for S. leptorhynchus (33 times slowed down). They illustrate pivot feeding in syngnathid fishes, which is characterised by a very quick dorsal rotation of the head followed by suction. Dr. Van Wassenbergh said the “bend and snap” technique used by the seahorse is vital for a species that is a weak swimmer because every extra millimeter means more food. He said the technique gives the seahorse a 20 percent larger strike zone than the pipefish.The pipefish swims around to catch its prey, and when prey is in sight it lifts its head slightly upwards and forwards to get its mouth close enough to suck the prey inside. The seahorses have an additional forward reaching component with its head (which is arched), meaning it straightens its neck to lift its head upwards, and so it can reach slightly further. This enables the seahorse to probe a larger volume of water for food while it waits for the prey to swim by, remaining stationary and with the tip of its tail attached to sea grass. Explore further Citation: How the seahorse might have got its shape (2011, January 27) retrieved 18 August 2019 from https://phys.org/news/2011-01-seahorse.html Seahorse – Hippocampus sp. Photo: Mohammed Al Momany, via Wikipedia.center_img Researchers, led by biomechanicist Dr. Sam Van Wassenbergh of the University of Antwerp in Belgium, wondered why the seahorse shape, consisting of a curled tail and striking arched head is so different from that of its relative, the pipefish, which is long, thin and straight like the ancestors of the seahorse.The scientists used a biomechanical analysis technique to study the shape and posture of the seahorse and pipefish and discovered that the seahorse can capture its prey of small shrimps and fish larvae at a greater distance from the eyes than the pipefish. They confirmed the mathematical analysis and computer animations with high-speed video footage of both types of fish in action. Dr Van Wassenbergh said the foraging behavior would have come first and then natural selection would favor those fish that had a larger strike distance. According to their research this created a selective pressure for the angle between head and trunk to increase.The paper was published in the journal Nature Communications. (PhysOrg.com) — The shape of the seahorse has long baffled marine scientists, but new research suggests the seahorse’s unique shape may have evolved to allow it to catch its food when it was further away. PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen Male seahorses are nature’s Mr. Mom, researchers saylast_img read more


DNA study on mummies suggests climate instability drove ancient Peruvians to migrate

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first_img More information: Climate change underlies global demographic, genetic, and cultural transitions in pre-Columbian southern Peru, Lars Fehren-Schmitz, PNAS, doi: 10.1073/pnas.1403466111AbstractSeveral archaeological studies in the Central Andes have pointed at the temporal coincidence of climatic fluctuations (both long- and short-term) and episodes of cultural transition and changes of socioeconomic structures throughout the pre-Columbian period. Although most scholars explain the connection between environmental and cultural changes by the impact of climatic alterations on the capacities of the ecosystems inhabited by pre-Columbian cultures, direct evidence for assumed demographic consequences is missing so far. In this study, we address directly the impact of climatic changes on the spatial population dynamics of the Central Andes. We use a large dataset of pre-Columbian mitochondrial DNA sequences from the northern Rio Grande de Nasca drainage (RGND) in southern Peru, dating from ∼840 BC to 1450 AD. Alternative demographic scenarios are tested using Bayesian serial coalescent simulations in an approximate Bayesian computational framework. Our results indicate migrations from the lower coastal valleys of southern Peru into the Andean highlands coincident with increasing climate variability at the end of the Nasca culture at ∼640 AD. We also find support for a back-migration from the highlands to the coast coincident with droughts in the southeastern Andean highlands and improvement of climatic conditions on the coast after the decline of the Wari and Tiwanaku empires (∼1200 AD), leading to a genetic homogenization in the RGND and probably southern Peru as a whole. To gain a clearer understanding of early Nasca, Wari and Tiwanaku peoples living in various parts of what is now Peru, the researchers collected DNA samples from 207 mummies found in both coastal and mountainous parts of the region. Mitochondrial analysis and Bayesian modeling indicated that people that had been living near the coast began migrating to the mountains sometime around 640 BC. They also found evidence of a reverse migration as people from the mountains migrated towards the coast around 1200 AD.The researchers compared the DNA evidence with prior research on climatic conditions during the same period. They found that around roughly 640 BC, climate variability due to el Nino or el Nina would have made growing crops in coastal valleys challenging. Also, they found that the highlands areas experienced a long term drought that began around 1200 AD, which would have driven people back down to the coasts. Both climate events coincide with the DNA evidence.Prior to this research, the general consensus among historians has been that the migrations that occurred in the area at the time were most likely due to the expansion and eventual collapse of the Wari empire. Now it appears that it was instead driven by climactic change, forcing people to move to where conditions were favorable for growing their food. The researchers note that the change would likely have had to have been significant as the people in the ancient societies demonstrated anticipatory agricultural adaptations that allowed them to cope with both floods and drought. The team notes that migrating back and forth between the coast and the highlands also appears to have caused homogenization of the peoples from the two areas. (Phys.org) —An international team of researchers has concluded that migrations by pre-Columbian Andean societies were due to climatic changes, rather than growth in the Wari empire, as was previously suggested. In their paper published in Proceedings of the National Academy of Sciences, the team describes how they conducted mitochondrial DNA analysis on mummies from the period combined with a Bayesian modeling approach to trace the migration activities of the people that lived in Peru between 840 BC and 1450 AD. Pikillaqta administrative center, built by the Wari civilization in Cusco. Credit: Wikipedia. CC BY-SA 3.0 © 2014 Phys.org Citation: DNA study on mummies suggests climate instability drove ancient Peruvians to migrate (2014, June 18) retrieved 18 August 2019 from https://phys.org/news/2014-06-dna-mummies-climate-instability-drove.htmlcenter_img El Niño expected to benefit US agriculture Explore further Journal information: Proceedings of the National Academy of Sciences This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more


Five times a queen

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first_imgShe was a queen, wife to no less than the mighty Pandavas; yet she was a woman in a patriarchal society who held little sway over her own fate. Draupadi might have lived in another era, but the fate she endured continues to befall numerous women in India and across the world even today.A presentation of the Films and Theater Society, the play is written and directed by contemporary writer Atul Satya Kaushik and is based in a Haryana village in 1960. Draupadi is an imaginative re-telling of certain chapters of Draupadi’a life that juxtaposes the life of the queen of the Pandavas in a contemporary setting, drawing parallels between her and the women of today. Also Read – ‘Playing Jojo was emotionally exhausting’With the men of this large family of Haryanvi rural performers gone out to attend a wedding feast, the women of the household decide to use the opportunity to re-enact an old play that was ‘banned’ by the male patriarchs who thought it would corrupt the minds of women.Performing the play, the women take up the roles of all characters including men and reprise the tragedies of their own lives. In the process they discover how closely their lives are a reflection of Draupadi’s life. This intense story unfolds in an incredibly light and seamless way and makes the production a literary marvel presented in a visually delightful manner. Like all other productions of the society this play is also high on folk music. Also Read – Leslie doing new comedy special with NetflixIt’s an out and out musical play with many songs of different styles such as Ragini, Qawwali, Ghazal, Heer etc; and tries to narrate a serious issue in a light way. The seriousness, however, is not lost and the play becomes a powerful commentary on the need of women emancipation.By bringing today’s generation closer to mythology in a new and interesting way, the play makes them draw important meanings from it. Be it Draupadi’s failure to find the love of the man she chose, her objectification in the gamble played by Yudhishtir or her public humiliation – the village women manage to find parallels for each of these tragedies amidst their own lives. In the end the women draw the conclusion that even if centuries have elapsed, nothing seems to have changed as far as their fate women is concerned.’Draupadi is not just a mythical character, she’s a metaphor for women of all times and ages. There is no dearth of Draupadis in our world; they are everywhere – be it in the villages of Haryana, in the thriving metropolitan of Delhi, in the slums of Mumbai, on the streets of Ahmedabad or in a village of Khyber Pakhtoonkhwah. This play talks about the helplessness of being a woman in a male dominated world which most of the women must have felt even today,’ says Kaushik. This not a performance to be missed. The tickets are available online at bookmyshow.com. Head over!last_img read more


All access pass

Posted On Aug 31 2019 by

first_imgArt lovers can head over to Gallery Five as it organises its next monthly art exhibition titled Excess Denied. The show displays a wide range of works by India’s leading and upcoming modern and contemporary artists. The participants are – Anjaneyulu Gundu, Arpit Biloria, Deviba Wala, Manish Barodia and Shahanshah Mittal. Excess Denied is an ode to purity of thought and action which have led to the creation of these artworks.The collection demonstrates the fundamental technical skills and conceptual strength of an artist. They blur the boundaries between the everyday and art without succumbing to histrionics and excesses. They embrace the basic tenets of being human and humane. Also Read – ‘Playing Jojo was emotionally exhausting’ ‘The utilitarian objects represented in my paintings speak of the lives of the people who handle/use them in their daily little histories’- says Gundu.  He believes that every object is an actor in a larger scene and every scene is part of another act. That is why he concentrates on the individual object in his hyper realistic paintings. Biloria noted, ‘Volume is something which can be realised even when you take away the distracting color’. White, he sees, as a ground, where images lay hiding. Black acts as connecting point between dimensions revealing these images. He plays with what exists and what does not. Also Read – Leslie doing new comedy special with NetflixDeviba summarises her minimal and usually monochrome abstract work as having a naive depth. Naive in the context that her art is one that’s kept devoid of all obvious influences of the daily life and today’s world but not in its literal sense. Her work consists of broad spectrum of lines intersecting into each other as if weaving a beguiling net for the viewer to immerse in. She wants her art forms to create a niche and exclusive mind space in the viewer thus letting him/her strike a chord with their inner self. The strength in her art is the ode to a life’s pure existence. The many subtle layers in Mittal’s paper work represent inner monologues which cannot be vocalized.last_img read more


Windies players being hoodwinked treated like schoolboys by board

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first_imgA strike could hit West Indies’ tour opener against India on Wednesday due to a row between leading West Indies players and their own union. The match in Kochi, where the teams are already assembled, is the first of five one-day internationals to be followed by three test matches and a Twenty20 international.The West Indies Players Association (WIPA) and the West Indies Cricket Board (WICB) signed a new agreement last month covering pay and conditions but all-rounder Dwayne Bravo said players were kept in the dark about the talks and would not accept the outcome. (Also Read: India Won’t be Scared of Windies as Narine Mystery Looms) ‘We believe we are being hoodwinked and are being treated like little school boys, yet we are being asked to perform and play as professionals,’ Bravo wrote in a letter to WIPA president Wavell Hinds published by the Caribbean website Wired868.com. Also Read – Khel Ratna for Deepa and Bajrang, Arjuna for Jadeja‘The players are of the view that as a matter of principle, we should not accept these conditions whereby we are being asked to play a series against India without any certainty of what are our obligations and what we will be playing for.’The WICB said in a statement on Tuesday that they were aware of the dispute and the possibility of a strike.‘It has also come to the WICB’s attention that the some of the players could withdraw their services for the first ODI. The WICB deeply regrets this apparent eventuality, especially in light of the tedious and substantial work which went into the good faith negotiations to arrive at the new, historic CBA/MOU.‘The WICB apologises to the fans, the BCCI and all other stakeholders should the first ODI be disrupted as a result of player action. The WICB is making every effort to ensure that it fulfills all its commitments and that cricket is played,’ said the statement.last_img read more


Budding talent

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first_imgHave you ever noticed how a child smoothly uses colors to produce the figments of his imagination on the sheet of paper kept in front of him? He doesn’t think twice before turning anything into a canvas for his squiggling hands. Just let him free and his imagination knows no bounds with colors. But as they grow up – an artist is lost somewhere between science and mathematics.Touchtalent.com, an online community for art and creativity is organizing a week long online art exhibition from 14 – 20 November. The theme of the exhibition is to overlap with the Children’s day and aims to catch the artists young and raw and promote them on a global scale. The last date for submitting entries is 13 November. Also Read – ‘Playing Jojo was emotionally exhausting’Through this exhibition, children can showcase any artwork that they have worked on – whatever inspires them because the imagination of children cannot be bound by a single theme. Touchtalent.com has taken a unique initiative to celebrate the spirit of art and creativity in each child and help them grow as an artist and monetize their artwork. Touchtalent connect creative users in over 192 countries. It has thus far organized more than ten global online art exhibitions with each generating around a million page views. This exhibition is expected to touch 2 million of page views. Also Read – Leslie doing new comedy special with NetflixMohd Wassem, Managing Director, Touchtalent.com said, ‘In the last few years, I have been greatly humbled and touched by the amount of talent there is in children around the world. We ask all the parents to urge their kids to bring out the artist in them and not hold them back – and update their artwork for this one of a kind exhibition.’This is Children’s only exhibition. They can submit their entries by 13 November with the hash tag #Youngcreators on www.touchtalent.com. Every selected entry would be awarded a  certificate of appreciation.last_img read more


TMC workers supporters stage protests against surging fuel prices

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first_imgKolkata: Trinamool Congress workers and supporters staged a protest demonstration at Baidyabati in Hooghly against rising prices of petrol and diesel.This comes a day after Chief Minister Mamata Banerjee expressed her concern over the sharp increase in prices of petrol and diesel. She tweeted on Sunday: “We are very concerned about the rising prices of petrol and diesel. This will certainly affect prices all around. Common people, farmers and many will suffer.” Also Read – Heavy rain hits traffic, flightsHundreds of workers of the party staged a demonstration at Naoga More near Baidyabati in Hooghly. They sought slogans against the “indifferent” attitude of the Centre and demanded its intervention in this connection.Many common people too joined the protest demonstration and demanded immediate steps so that prices do not soar higher. The demonstration took place in front of a refueling station in the area and they held a rally along the GT Road later. On Monday, the petrol and diesel prices in Kolkata increased by 33 paise and 25 paise respectively. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedIt took the prices of petrol and diesel to Rs 79.24 and Rs 70.37 respectively, hitting an all-time high.According to the party workers, they have organised the protest rally apprehending that this price hike would also increase the prices of essential goods as transportation cost will go up and adversely affect common people.According to the members of the West Bengal Petroleum Dealers’ Association, the sale of both petrol and diesel has quickly dropped as the news of price hike spread. Tushar Kanti Sen, president of the association said: “I apprehend further drop in the sale if prices keep increasing.”With the increase in the prices, a section of bus owners have started demanding a fare hike and decided to place their demands before the state Transport department. It may be mentioned that since the change of guard in the state in 2011, the state Transport Department has always taken necessary steps to ensure that common people do not face inconvenience. Sources said there was a preliminary discussion at the state transport department regarding framing a new policy, which would allow increase of bus fares when fuel prices go up and will get decreased with a fall in the fuel prices.last_img read more


2 undertrial prisoners call up 2 businessmen from correctional home demand ransom

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first_imgKolkata: Two under-trail prisoners allegedly called up two businessmen from a correctional home and demanded ransom failing which, they would face dire consequences. The incident took place at Dum Dum Central Correctional Home. The authorities have ordered a probe into the incident that would be conducted to find out where from they had received the mobile phone. The duo — Biswajit Das and Bapi Raman were arrested on charges of murdering a Trinamool Congress leader that took place at Kestopur in February 2016. It was alleged that they had called up two Baguiati-based businessmen and demanded Rs 10 lakh from them. They also threatened them with dire consequences if they failed to pay the amount. The businessmen told the cops that they had received the phone call from the duo on May 24 and threatened to kill them if they informed the matter to the police. Later they gathered courage and lodged a complaint with the local police station. On the basis of the compliant, the police have started a probe in this regard and are interrogating the duo. The correctional home authorities are also conducting a probe in this regard.last_img read more


CM hails states move to coach SCST students

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first_imgKolkata: Chief Minister Mamata Banerjee on Saturday hailed the initiative of the state government in providing high-end professional coaching to SC/ST students for engineering and medical entrance examinations that have yielded very good results.”The unique initiative of our government to provide high-end professional coaching to SC/ST students for engineering and medical entrance examinations have yielded great results. Out of 939 students who took coaching this year, 348 SC and 76 ST students have ranked in Joint Entrance Examination for Engineering,” Banerjee tweeted. Also Read – Heavy rain hits traffic, flightsThe Chief Minister further informed through her tweet that among the SC/ST students, 95 have secured ranks among the top 1,000.”In medical stream also, 125 SC/ST aspirants qualified in NEET and are likely to qualify for admission in reputed government institutions. My heartiest congratulations and best wishes to all of them,” Banerjee further tweeted.She maintained that the state government is already taking steps to expand such specialised coaching arrangements so that more and more students can benefit from it and get placed in professional courses. It may be mentioned that Career Paramarsh Kendra (CPK) to provide information regarding jobs and training to the SC/ST and unemployed youth, has been set up in the city in March this year by the Backward Classes Welfare and Tribal Development department. It will come up with 30 centres by the end of 2017-18 fiscal and another 37 in 2018-19 thereby covering all 67 sub-divisions in the state within a span of less than two years. The need to set up the CPKs was felt as the facility for getting information on career prospects, be it in the educational sector or employment, is still in a primitive level, particularly in the rural areas.last_img read more


Govt taking measures to be selfreliant in fish production CM

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first_imgKolkata: Chief Minister Mamata Banerjee in the state Assembly on Thursday said the state government is taking all possible measures to become self-reliant in fish production in the next few years.”We are moving towards becoming self-reliant in fish production and have been able to bring down the fish deficit in terms of consumption drastically. Around 700 agricultural ponds have been identified for fish cultivation and fish rearing has been taken up in 75,000 ponds in the state that have been renovated under the Jal Dharo Jal Bharo scheme. We have distributed fishlings across the state for encouraging fish cultivation in waterbodies,” Banerjee said in reply to a query on fish cultivation from Trinamool Congress MLA Jyotirmoy Kar. Also Read – Rain batters Kolkata, cripples normal lifeThe Chief Minister also mentioned that the state Fisheries and state Tourism departments have joined hands to develop the concept of fish tourism in the state.State Fisheries minister Chandranath Sinha said Fish Tourism has already been introduced at Nalban and Henry’s Island near Bakkhali in South 24-Parganas.”Tourists who visit these places are provided with the opportunity of angling. The fish caught by them is cooked and then offered to them as part of their lunch,” he added. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedIn Bengal, the demand for fish is 18.84 lakh metric tonnes per year and the production is 17.42 lakh metric tonnes. Around 1.5 lakh metric tonnes is exported every year. Thus, there is a dearth of 1.72 lakh metric tonnes and the state has to import from other states particularly Andhra Pradesh to make up forthe deficit.”People in Bengal have a special liking for small fishes like mourala, puti, bata and similar fishes. These fishes are hardly consumed by other states in the country. So, we are also taking steps to ensure that people can relish these kinds,” the Chief Minister said.It may be mentioned that the state Fisheries department has adopted Moyna model in nine districts where river water is being channelized to ponds for fish cultivation at a brisk pace.”We have plans to have 15 districts under the Moyna model by this year,”Sinha said.He added that efforts are also being taken up for cultivating Ilish (Hilsa) in three waterbodies under the department.last_img read more