China Science & Technology Forum

[ahojunk]

Chinese scientists reveal why giant pandas and red pandas evolve to eat bamboo
2017-01-17 09:26 | Xinhua | Editor: Gu Liping

Chinese researchers said Monday they have uncovered the genetic basis of why giant pandas and red pandas have evolved independently to have shared features such as a bamboo-based diet and false thumb.

Despite being classified as carnivores, both giant pandas and red pandas, which separately evolved from meat-eating ancestors and diverged from each other more than 40 million years ago, subsist almost entirely on bamboo -- a phenomenon termed convergent evolution, where similar traits arise in two unrelated or distantly related species.

Additionally, both species possess a false thumb, which enables the animals to adroitly grasp bamboo.

To uncover the genetic basis of such convergence, Fuwen Wei and colleagues from the Institute of Zoology, part of the Chinese Academy of Sciences, sequenced the genome of a wild male red panda and compared it with the reassembled genome of the giant panda. Their findings were published in the recent issue of U.S. journal Proceedings of the National Academy of Sciences.

The results confirmed that giant pandas belong to the family Ursidae together with polar bears, whereas red pandas belong to the superfamily Musteloidea together with ferrets and that the two species separated 47.5 million years ago, slightly earlier than previous molecular-based estimate of 43 million years ago.

Genome analysis revealed signs of adaptive convergence in 70 genes, including two genes, known as DYNC2H1 and PCNT, that are involved in false thumb development.

Further, enzymes involved in dietary protein digestion and amino acid utilization as well as proteins involved in vitamin metabolism and absorption showed signs of adaptive convergence, suggesting that these genes may have similarly evolved to support and supplement a bamboo-based diet.

Giant and red panda genomes also share 10 pseudogenes, or "false" genes, which look like real genes but have no apparent function.

Notably, the TAS1R1 gene, which enables carnivores to taste meat's umami flavor, has been pseudogenized in both pandas, reflecting the animals' shift from carnivory to omnivory and, ultimately, herbivory.

"Our findings provide rich insights into genetic convergence mechanisms underlying phenotypic convergence and adaptation to a specialized bamboo diet in both pandas," the researchers wrote in their paper.

"These findings demonstrate that genetic convergence occurred at multiple levels spanning metabolic pathways, amino acid convergence, and pseudogenization, providing a fascinating example for genome-scale convergent evolution analysis of dietary shift and specialization."

 

[JSCh]

January 18, 2017 | By Inga Kiderra and Anthony King
Mandarin Makes You More Musical?

Photo by iStock_DragonImages.​

Mandarin makes you more musical – and at a much earlier age than previously thought. That’s the suggestion of a new study from the University of California San Diego. But hold on there, overachiever parents, don’t’ rush just yet to sign your kids up for Chinese lessons instead of piano.

In a paper published in Developmental Science, an international team of researchers shows that among the preschool set – or young children between the ages of 3 and 5 – native speakers of Mandarin Chinese are better than their English-speaking counterparts at processing musical pitch.

The implications of the findings go beyond determining who may have a head-start in music, the researchers say. The work shows that brain skills learned in one area affect learning in another.

“A big question in development, and also in cognition in general, is how separate our mental faculties actually are,” said lead author Sarah Creel of the Department of Cognitive Science in UC San Diego’s Division of Social Sciences. “For instance, are there specialized brain mechanisms that just do language? Our research suggests the opposite – that there’s permeability and generalization across cognitive abilities.

The researchers conducted two separate experiments with similar groups of young Mandarin Chinese learners and English learners. They tested a total of 180 children on tasks involving pitch contour and timbre. Where the English and Mandarin speakers performed similarly on the timbre task, the Mandarin speakers significantly outperformed on pitch, aka tone.

Mandarin is a tone language. In a tone language, the tone in which a word is said not only conveys a different emphasis or emotional content, but an altogether different meaning. For instance, the syllable “ma” in Mandarin can mean “mother,” “horse,” “hemp” or “scold,” depending on the pitch pattern of how it’s spoken. Mandarin-language learners quickly learn to identify the subtle changes in pitch to convey the intended outcome, while “ma” in English can really only mean one thing: “mother.” It’s the linguistic attention to pitch that gives young Mandarin speakers an advantage in perceiving pitch in music, the authors conclude.

Sarah Creel.​

“Both language and music contain pitch changes, so if language is a separate mental faculty, then pitch processing in language should be separate from pitch processing in music,” Creel said. “On the other hand, if these seemingly different abilities are carried out by overlapping cognitive mechanisms or brain areas, then experience with musical pitch processing should affect language pitch processing, and vice versa.”

Co-author Gail Heyman, of UC San Diego’s Department of Psychology, who specializes in development, added: “Demonstrating that the language you speak affects how you perceive music –at such an early age and before formal training – supports the theory of cross-domain learning.”

Tone languages are common in parts of Africa, East Asia and Central America, with estimates that as much as 70 percent of world languages may be considered tonal. Other tonal languages besides Mandarin include Thai, Yoruba and Xhosa.

Creel and Heyman’s work follows on a hypothesis first put forth by Diana Deutsch, also of UC San Diego, that experience with a tonal language leads to enhanced pitch perception in music. Deutsch studied skilled adult students of music and tested them on absolute or “perfect” pitch. Absolute pitch is the relatively rare ability to recognize a musical note without reference to any other notes.

Relative pitch, or understanding the pitch relationships between notes, is the focus of the present study. Relative pitch allows you to sing in key and be in tune with other people around you.

“We show for the first time that tone-language experience is associated with advanced musical pitch processing in young children,” the study co-authors write. “There are far-reaching theoretical implications for neuroscience and behavior, and our research has important practical implications for designing early intervention programs, or ‘brain training’ regimes.’”

But that said, don’t ditch your child’s music lessons for language, or language lessons for music, Heyman and Creel caution. It’s still true that to succeed at music, you need to study music. And learning an additional language is a demonstrably good thing in itself, too – whether or not it makes you a better musician.

The other co-authors are: Mengxing Weng of Zhejiang Normal University, China; Genyue Fu of Hangzhou Normal University, China; and Kang Lee of Zhejiang Normal University, UC San Diego and the Ontario Institute for Studies in Education, Canada.

Creel was supported by a National Science Foundation CAREER Award BCS-1057080. Lee and Fu were supported by National Natural Science Foundation of China grants 31371041 and 31470993 and the Natural Sciences and Engineering Research Council of Canada.


http://ucsdnews.ucsd.edu/pressrelease/mandarin_makes_you_more_musical

 

[JSCh]

FOR IMMEDIATE RELEASE
ACS News Service Weekly Press Pac: Wed Jan 18 10:17:11 EST 2017
Toward a ‘smart’ patch that automatically delivers insulin when needed

"H2O2-Responsive Vesicles Integrated with Transcutaneous Patches for Glucose-Mediated Insulin Delivery"
ACS Nano

Tiny, painless microneedles on a patch can deliver insulin in response to rising glucose levels.
Credit: American Chemical Society

Treatment for certain diabetes cases involves constant monitoring of blood-glucose levels and daily insulin shots. But scientists are now developing a painless “smart” patch that monitors blood glucose and releases insulin when levels climb too high. The report on the device, which has been tested on mice, appears in the journal ACS Nano.

People with Type 1 diabetes don’t make insulin — a hormone that regulates blood glucose, or sugar. Those with Type 2 diabetes can’t use insulin effectively. Either way, glucose builds up in the blood, which can lead to a host of health problems, including heart disease, stroke, blindness and amputation of toes, feet or legs. To avoid these outcomes, people with Type 1 or advanced Type 2 diabetes regularly prick their fingers to measure blood-sugar levels, and some patients must inject themselves with insulin when needed. But sometimes, despite a person’s vigilance, glucose levels can still get out of whack. Zhen Gu and colleagues wanted to come up with a simpler, more effective, shot-free way to manage diabetes.

The researchers developed a skin patch covered in painless microneedles that are loaded with tiny insulin-carrying pouches. The pouches are engineered to break apart rapidly and release the insulin in response to rising glucose levels. Diabetic mice wearing the patch maintained consistent concentrations of insulin in their blood. When these mice received a shot of glucose, their blood sugar levels spiked initially, but then fell to normal levels within two hours.

The authors acknowledge funding from the American Diabetes Association, National Institutes of Health and the National Science Foundation.



Toward a ‘smart’ patch that automatically delivers insulin when needed - American Chemical Society

Journal Reference:

1. Xiuli Hu, Jicheng Yu, Chenggen Qian, Yue Lu, Anna R. Kahkoska, Zhigang Xie, Xiabin Jing, John B. Buse, Zhen Gu. H2O2-Responsive Vesicles Integrated with Transcutaneous Patches for Glucose-Mediated Insulin Delivery. ACS Nano, 2017; DOI: 10.1021/acsnano.6b06892

 

[JSCh]

Sunday, January 22, 2017, 12:21
China uses 3D printer in pediatric heart surgery
By Xinhua

Surgeons prepare to perform operation on Yuanyuan in a hospital in Taiyuan, capital of north China's Shanxi Province, June 2, 2012. (Yan Yan / Xinhua)​

CHANGSHA - Chinese surgeons in a central China hospital have succeeded in performing two complex pediatric heart surgeries using 3D printing technology.

The first patient was a 13-year-old girl suffering from hypertrophic obstructive cardiomyopathy, which causes her heart muscle to grow abnormally thick. The second was a 3-year-old boy with severe left ventricular outflow tract obstruction, said Yang Yifeng, a cardiologist with the Second Xiangya Hospital of Central South University in Hunan province.

Yang said the left ventricle is responsible for pumping oxygenated blood to tissues all over the body. Symptoms of left ventricular outflow tract obstruction include shortness of breath, sensation of rapid, fluttering heartbeats during exercise, chest pain, and fainting.

In either of the two cases, because of the complexity involved, doctors decided to use a 3D printer to produce a 1:1 replica of the patient's heart. The model allows doctors to carefully study the disease and plan their surgery, Yang said.

It is the first time 3D printing technology is used in Hunan for pediatric cardiovascular surgery. It proves quite successful and the two patients are recovering well, Yang added.

3D printing is being embraced by doctors in China's major hospitals for surgeries and training, as the technology greatly improves surgery precision and helps doctors to discuss the ailment with their colleagues and sometimes their patients.

 

[JSCh]

Data Mining Solves the Mystery of Your Slow Wi-Fi Connection
Chinese researchers have worked out the reasons for why Wi-Fi can take so long to connect.

• by Emerging Technology from the arXiv
• January 20, 2017

Wi-Fi is one of the 21st century’s great liberators. The ability to connect wirelessly to the Internet in a huge variety of locations is the enabling technology for all kinds of flexible working arrangements. Indeed, it has turned the coffee shop into one of society’s more productive work places.

But anyone who regularly uses Wi-Fi will be aware of an embarrassing problem: it sometimes takes an age to connect to Wi-Fi and sometimes connections are not possible at all. The awful truth about Wi-Fi is that all too often, it simply does not work.

And that raises an important question: why? What is it about these state-of-the-art wireless networks and the devices that connect to them that so often fails?

Today we get an answer thanks to the work of Changhua Pei at Tsinghua University in China and a few pals who have measured how long it took for 400 million different Wi-Fi sessions to connect. And they’ve used their data to work out what typically goes wrong and how it can be avoided.

--> https://www.technologyreview.com/s/...es-the-mystery-of-your-slow-wi-fi-connection/

 

[JSCh]

Scientists: Carbon Nanotubes Would Outperform Silicon Transistors at the Same Scale
By Dexter Johnson
Posted 19 Jan 2017 | 19:00 GMT

Illustration: Peking University/Science
​

The end appears nigh for scaling down silicon-based complementary metal-oxide semiconductor (CMOS) transistors, with some experts seeing the cutoff date as early as 2020.

While carbon nanotubes (CNTs) have long been among the nanomaterials investigated to serve as replacement for silicon in CMOS field-effect transistors (FETs) in a postsilicon future, they have always been bogged down by some frustrating technical problems. But, with some of the main technical showstoppers having been largely addressed—like sorting between metallic and semiconducting carbon nanotubes—the stage has been set for CNTs to start making their presence felt a bit more urgently in the chip industry.

Peking University scientists in China have now developed carbon-nanotube field-effect transistors (CNT FETs) having a critical dimension—the gate length of just 5 nanometers—that would outperform silicon-based CMOS FETs at the same scale. The researchers claim in the journal Science that this marks the first time that carbon-nanotube CMOS FETs under 10 nanometers have been reported.

More important than just being the first, the Peking group showed that their CNT-based FETs can operate faster and at a lower supply voltage than their silicon-based counterparts.

At a 0.4-volt supply voltage, the current that flows through the CNT transistor is larger than what you’d get from the best silicon CMOS transistors at a 0.7-V supply voltage, according to Peking University’s Lian-Mao Peng in an email interview with IEEE Spectrum. (The “best” according to Peng is Intel’s 14-nm-node CMOS.) Because the gate’s capacitance is smaller for a carbon-nanotube transistor, even if the silicon devices were scaled down to the size of the CNT device, the latter would still switch faster, he says. The intrinsic delay caused by the gate capacitance for 10-nm CNT CMOS is about 70 femtoseconds, says Peng. That’s just one-third of the value (220 fs) of 14-nm silicon CMOS.

As with all the field-effect transistors, current flows through a channel between the source and drain under the control of voltage at the gate. In the Peking design, the channel through which the carriers move is made out of a single carbon nanotube and the source and drain are both graphene. This CNT channel is either p-type—conducting positive charge carriers, or holes—or n-type, which uses electrons. It is this combination of the p-type and n-type devices that constitutes the “complementary” of CMOS and keeps power consumption low when switching logic states.

Unlike most carbon-based and two-dimensional devices, the CNT FETs that the Chinese researchers have developed are not “back gated.” Back-gated devices—in which the gate electrode lies beneath a layer of insulation and the nanotube lies atop the insulation—are generally more difficult to integrate into complicated circuits.

Instead, the device Peng and colleagues constructed uses a gate that drapes over the top of the carbon-nanotube channel. “Top-gated FETs can provide higher gate efficiency than the back-gated devices since the CNT is almost surrounded by the top gate,” says Peng. “Also, top-gated FETs provide better stability than back-gated devices since the CNT channel is protected from influences of the outside world by the top gate.”

While the researchers concede that the use of individual single-walled carbon nanotubes to construct their devices is not suitable for producing large-scale integrated circuits, they are confident they can overcome this without changing much.

“Now that we have confirmed the potential of CNT CMOS transistors in the work, we can construct CMOS FETs with similar performance on aligned CNT arrays with high density and high semiconducting purity using the same fabrication process.”

With the ability to scale down silicon CMOS petering out in the coming years, there is some question as to whether there is enough time to replace silicon, or whether it is even worth the effort.

“We believe CNT electronics have a good chance to replace [silicon] CMOS technology at 5-nm nodes by 2022,” says Peng. As optimistic as Peng is, he remains cautious about the engineering challenges that they still face.

“While we can use the currently available CNTs…to fabricate large-scale CNT ICs, it still requires one to two years to get the ideal CNT form for ICs,” he says. Nonetheless, Peng believes that they will be able to make wafers full of ICs in the next few years using their process.


Scientists: Carbon Nanotubes Would Outperform Silicon Transistors at the Same Scale - IEEE Spectrum

Paper:

Chenguang Qiu, Zhiyong Zhang, Mengmeng Xiao, Yingjun Yang, Donglai Zhong, Lian-Mao Peng. "Scaling carbon nanotube complementary transistors to 5-nm gate lengths", Science (2017). DOI: 10.1126/science.aaj1628

Moving transistors downscale
One option for extending the performance of complementary metal-oxide semiconductor (CMOS) devices based on silicon technology is to use semiconducting carbon nanotubes as the gates. Qiu et al. fabricated top-gated carbon nanotube field-effect transistors with a gate length of 5 nm. Thin graphene contacts helped maintain electrostatic control. A scaling trend study revealed that, compared with silicon CMOS devices, the nanotube-based devices operated much faster and at much lower supply voltage, and they approached the limit of one electron per switching operation.
Science, this issue p. 271

Abstract
High-performance top-gated carbon nanotube field-effect transistors (CNT FETs) with a gate length of 5 nanometers can be fabricated that perform better than silicon complementary metal-oxide semiconductor (CMOS) FETs at the same scale. A scaling trend study revealed that the scaled CNT-based devices, which use graphene contacts, can operate much faster and at much lower supply voltage (0.4 versus 0.7 volts) and with much smaller subthreshold slope (typically 73 millivolts per decade). The 5-nanometer CNT FETs approached the quantum limit of FETs by using only one electron per switching operation. In addition, the contact length of the CNT CMOS devices was also scaled down to 25 nanometers, and a CMOS inverter with a total pitch size of 240 nanometers was also demonstrated.​

 

[JSCh]

Moth gut bacteria create antibiotic to defend their host: study
Source: Xinhua 2017-01-20 05:14:53

WASHINGTON, Jan. 19 (Xinhua) -- Chinese and German researchers have found that some species of moths may have evolved an "ironic" strategy to resist microbial infections and flourish in microbe-rich environments.

In a study published Thursday in the U.S. journal Cell Chemical Biology, they reported for the first time that a bacterial species commonly found in the gut of the cotton leafworm and other insects secretes a powerful antimicrobial agent that kills off competing bacteria while defending its host against pathogens.

"It has long been proposed native gut bacteria are an important component of host defense, but until now, the responsible species and molecular mechanism have not been clearly demonstrated," first author Yongqi Shao of China's Zhejiang University, said in a statement.

"We show that the evolutionary success of insects is partially based on a symbiotic association with gut microbes, which co-evolved with their hosts over millions of years."

Insects are the largest group of animals on Earth, comprising over a million known species, nearly half of which are herbivores.

It's not uncommon that insect herbivores ingest a wide variety of potentially harmful microorganisms during a feast, yet they are remarkably resistant to infections.

"Increasing evidence in both vertebrates and invertebrates suggests that gut bacteria defend hosts against invading microbes," said Shao.

"But the species that exert this protective effect have rarely been identified, leaving the molecular mechanism of action unclear."

In the new study, Shao and senior study author Wilhelm Boland of the Max Planck Institute for Chemical Ecology looked at the cotton leafworm, Spodoptera littoralis, which is one of the most widespread insect herbivores in the temperate regions, causing substantial economic losses in crop production.

They found that the composition of gut microbes colonizing this pest changes dramatically during larval development.

Whereas young larvae were inhabited by a variety of virulent Enterococcus species, older larvae were dominated by E. mundtii, which has rarely been documented as a pathogen, Shao said.

Further research showed that E. mundtii inhibited the growth of other related bacterial species by secreting an antimicrobial peptide called mundticin KS.

While this toxin was undetectable in young larvae, it dramatically increased in abundance in older larvae due to expansion of the E. mundtii population, shaping the microbiome with surprising efficiency.

In other words, the antimicrobial provides a competitive advantage for E. mundtii, contributing to its dominance in the gut microbiome, while protecting the cotton leafworm against pathogens.

"We expect that protective associations with antibiotic-producing bacteria is a common strategy of insects against microbial invaders," Boland said.

The researchers said they will next examine whether similar mechanisms exist in other insect species, and look for additional toxic compounds that shape the microbiome during host development.

They believed that the findings could have widespread implications for agriculture and health.

For example, antimicrobial peptides could be used as food preservatives, and understanding the role of indigenous gut residents could contribute to the development of novel biocontrol strategies against herbivorous insect pests.

 

[JSCh]

China to invest ¥4.8b in world’s most powerful synchrotron light source
Sprawling facility to explore properties of all sorts of matter under brilliant beams of light for applications ranging from medicine to new materials and defence

PUBLISHED : Monday, 23 January, 2017, 3:45pm
UPDATED : Monday, 23 January, 2017, 3:45pm

Josh Ye

China will invest 4.8 billion yuan (HK$5.4 billion) to build the world’s brightest synchrotron light source, state broadcaster CCTV reports.

A synchrotron is a source of brilliant light that scientists use to explore the structural and chemical properties of materials at the molecular level, according to the website of the Canadian Light Source synchrotron.

A synchrotron produces light by using radio frequency waves and powerful electromagnets to accelerate electrons to nearly the speed of light. Energy is added to the electrons as they accelerate so that, when the magnets alter their course, they naturally emit a very brilliant, highly focused light.

Different spectra of light such as infrared, ultraviolet, and X-rays, are directed down beamlines where researchers choose the desired wavelength to study their samples.

The researchers observe the interaction between the light and matter in their sample. The technology can probe matter and analyse a host of physical, chemical, geological, and biological processes.

Information obtained by scientists can help design new drugs, examine the structure of surfaces to develop more effective motor oils, build smaller, more powerful computer chips, develop new materials for safer medical implants to name just a few applications, Canadian Light Source says.

Construction of China’s newest synchrotron, its fourth, is expected to start in Beijing by November next year and take six years to complete, according to the Chinese Academy of Sciences.

China three operating synchrotron are located in Beijing, Shanghai and Hefei in Anhui province. But the academy said the new synchrotron is of a new generation would even outshine Sweden’s MAX IV, currently the world’s most advanced synchrotron light source, by 10 times.

Even with its three operating synchrotrons, China has made significant progress the field. Shanghai’s Synchrotron Radiation Facility, for example, has played a key role in revealing the inner mechanism of various cancers.

Dong Yuhui, a researcher at the academy, said the new Beijing synchrotron would contribute greatly to developing aerospace materials, which is crucial to national security, according to the CCTV report.


China to invest ¥4.8b in world’s most powerful synchrotron light source | South China Morning Post

 

[JSCh]

24 January 2017
CUHK Biophysicists Discover Hidden Order in Bacterial Collective Motion
Provides new direction of study on biomedicine and active matters

An international team led by scientists at Physics Department of the Chinese University of Hong Kong (CUHK) discovered a surprising form of biological collective motion: PhD students Mr. Song Liu and Mr. Chong Chen from the laboratory of Prof. Yilin Wu, a biophysicist and faculty member of CUHK Physics, revealed that millions of motile cells in dense bacterial suspensions can self-organize into highly robust collective oscillatory motion, while individuals move in an erratic manner. This ‘weak synchronization’ phenomenon presents a novel mechanism of oscillatory behavior in multicellular systems and constitutes a new type of ordered active matter. Experimental evidence, together with a mathematical model developed by theorists Prof. Hugues Chaté from CEA-Saclay in France and Prof. Xia-qing Shi from Soochow University in mainland China, demonstrate that the self-organized collective oscillatory motion may result from spontaneous symmetry breaking of bacterial motion mediated by purely local interactions between individual cells. The team’s work has just been published in the international scientific journal Nature.

These findings expand the knowledge of self-organized phenomena in biological systems. Collective oscillatory behavior is ubiquitous in nature and it plays a vital role in many biological processes, such as embryogenesis, organ development, and pace-making in neuron networks. Collective oscillations in multicellular systems studied to date often arise from long-range coupling between individual cells that display inherent oscillations. In stark contrast, the collective oscillation in dense bacterial suspension discovered by the team does not require long range coupling, or even inherent oscillation of individual cells. Instead, it emerges from averaging large numbers of erratic but weakly-coupled trajectories of single bacteria; as a result it is elusive and has been previously unnoticed. Many bacteria live in surface-associated communities known as biofilms that are important to ecology and human health. The uncovered collective oscillation may have profound effect on the formation and structure of bacterial biofilms. The researchers expect to see the unique mechanism of collective oscillation in other biological processes that involve a large population of cells and hope to foster biomedical research.

Apart from facilitating studies in microbiology and biomedicine, the reported phenomenon will provide new direction in studying active matter systems. As a fast-growing and interdisciplinary field, active matter science studies systems composed of units where energy is spent to produce motion. This includes all living organisms from cells to animals, the subcellular constituents driven by molecular motors, and synthetic materials resulting from the self-organization of active elements; self-organization principles learned from these systems may find applications in tissue engineering and in fabricating new bio-inspired devices or materials. The collective oscillations revealed here constitute the first known instance of weak synchronization of random trajectories. This provides new insights for understanding the physics of self-organization in non-equilibrium systems. The way this weak synchronization arises from local interactions may inspire new strategies for designing swarming robots that are able to perform collective tasks without central control.

Chong Chen, Song Liu, Xiaqing Shi, Hugues Chaté, Yilin Wu. Weak synchronization and large-scale collective oscillation in dense bacterial suspensions. Nature (2017). doi:10.1038/nature20817.




CUHK Biophysicists Discover Hidden Order in Bacterial Collective Motion Provides new direction of study on biomedicine and active matters | CUHK Communications and Public Relations Office

 

[JSCh]

Bag-like sea creature was humans’ oldest known ancestor
Published on 30/01/2017

Artist’s reconstruction of Saccorhytus coronarius, based on the original fossil finds. The actual creature was probably no more than a millimetre in size

Researchers have identified traces of what they believe is the earliest known prehistoric ancestor of humans – a microscopic, bag-like sea creature, which lived about 540 million years ago.

Named Saccorhytus, after the sack-like features created by its elliptical body and large mouth, the species is new to science and was identified from microfossils found in China. It is thought to be the most primitive example of a so-called “deuterostome” – a broad biological category that encompasses a number of sub-groups, including the vertebrates.

If the conclusions of the study, published in the journal Nature, are correct, then Saccorhytus was the common ancestor of a huge range of species, and the earliest step yet discovered on the evolutionary path that eventually led to humans, hundreds of millions of years later.

Modern humans are, however, unlikely to perceive much by way of a family resemblance. Saccorhytus was about a millimetre in size, and probably lived between grains of sand on the seabed. Its features were spectacularly preserved in the fossil record – and intriguingly, the researchers were unable to find any evidence that the animal had an anus.

The study was carried out by an international team of academics, including researchers from the University of Cambridge in the UK and Northwest University in Xi’an China, with support from other colleagues at institutions in China and Germany.

Simon Conway Morris, Professor of Evolutionary Palaeobiology and a Fellow of St John’s College, University of Cambridge, said: “We think that as an early deuterostome this may represent the primitive beginnings of a very diverse range of species, including ourselves. To the naked eye, the fossils we studied look like tiny black grains, but under the microscope the level of detail is jaw-dropping. All deuterostomes had a common ancestor, and we think that is what we are looking at here.”

Degan Shu, from Northwest University, added: “Our team has notched up some important discoveries in the past, including the earliest fish and a remarkable variety of other early deuterostomes. Saccorhytus now gives us remarkable insights into the very first stages of the evolution of a group that led to the fish, and ultimately, to us.”

Most other early deuterostome groups are from about 510 to 520 million years ago, when they had already begun to diversify into not just the vertebrates, but the sea squirts, echinoderms (animals such as starfish and sea urchins) and hemichordates (a group including things like acorn worms). This level of diversity has made it extremely difficult to work out what an earlier, common ancestor might have looked like.

The Saccorhytus microfossils were found in Shaanxi Province, in central China, and pre-date all other known deuterostomes. By isolating the fossils from the surrounding rock, and then studying them both under an electron microscope and using a CT scan, the team were able to build up a picture of how Saccorhytus might have looked and lived. This revealed features and characteristics consistent with current assumptions about primitive deuterostomes.

Dr Jian Han, of Northwest University, said: “We had to process enormous volumes of limestone – about three tonnes – to get to the fossils, but a steady stream of new finds allowed us to tackle some key questions: was this a very early echinoderm, or something even more primitive? The latter now seems to be the correct answer.”

In the early Cambrian period, the region would have been a shallow sea. Saccorhytus was so small that it probably lived in between individual grains of sediment on the sea bed.

The study suggests that its body was bilaterally symmetrical – a characteristic inherited by many of its descendants, including humans – and was covered with a thin, relatively flexible skin. This in turn suggests that it had some sort of musculature, leading the researchers to conclude that it could have made contractile movements, and got around by wriggling.

Perhaps its most striking feature, however, was its rather primitive means of eating food and then dispensing with the resulting waste. Saccorhytus had a large mouth, relative to the rest of its body, and probably ate by engulfing food particles, or even other creatures.

A crucial observation are small conical structures on its body. These may have allowed the water that it swallowed to escape and so were perhaps the evolutionary precursor of the gills we now see in fish. But the researchers were unable to find any evidence that the creature had an anus. “If that was the case, then any waste material would simply have been taken out back through the mouth, which from our perspective sounds rather unappealing,” Conway Morris said.

The findings also provide evidence in support of a theory explaining the long-standing mismatch between fossil evidence of prehistoric life, and the record provided by biomolecular data, known as the “molecular clock”.

Technically, it is possible to estimate roughly when species diverged by looking at differences in their genetic information. In principle, the longer two groups have evolved separately, the greater the biomolecular difference between them should be, and there are reasons to think this process is more or less clock-like.

Unfortunately, before a point corresponding roughly to the time at which Saccorhytus was wriggling in the mud, there are scarcely any fossils available to match the molecular clock’s predictions. Some researchers have theorised that this is because before a certain point, many of the creatures they are searching for were simply too small to leave much of a fossil record. The microscopic scale of Saccorhytus, combined with the fact that it is probably the most primitive deuterostome yet discovered, appears to back this up.

The findings are published in Nature. Reference: Jian Han, Simon Conway Morris, Qiang Ou, Degan Shu and Hai Huang. Meiofaunal deuterostomes from the basal Cambrian of Shaanxi (China). DOI: 10.1038/nature21072.

Inset image: Photographs of the fossils show the spectacularly detailed levels of preservation which allowed researchers to identify and study the creature. Credit: Jian Han.


Bag-like sea creature was humans’ oldest known ancestor | St John's College, Cambridge

 

[JSCh]

Academics build ultimate solar-powered water purifier

From the top left corner, moving clockwise, the four images depict: University at Buffalo students performing an experiment, clean drinking water, water evaporating, and black carbon wrapped around plastic in water with evaporated vapor on top evaporated water. Credit: University at Buffalo.

The device could aid people lacking drinking water and those affected by natural disasters
http://www.buffalo.edu/news/about-us/staff/nealon.html
By Cory Nealon
Release Date: January 30, 2017

A floating solar still prototype that researchers used for some of experiments. Credit: University at Buffalo.

BUFFALO, N.Y. — You’ve seen Bear Grylls turn foul water into drinking water with little more than sunlight and plastic.

Now, academics have added a third element — carbon-dipped paper — that may turn this survival tactic into a highly efficient and inexpensive way to turn saltwater and contaminated water into potable water for personal use.

The idea, which could help address global drinking water shortages, especially in developing areas and regions affected by natural disasters, is described in a study published online today (Jan. 30, 2017) in the journal Global Challenges.

“Using extremely low-cost materials, we have been able to create a system that makes near maximum use of the solar energy during evaporation. At the same time, we are minimizing the amount of heat loss during this process,” says lead researcher Qiaoqiang Gan, PhD, associate professor of electrical engineering in the University at Buffalo School of Engineering and Applied Sciences.

Additional members of the research team are from UB’s Department of Chemistry, Fudan University in China, the University of Wisconsin-Madison and the lab of Gan, who is a member of UB’s New York State Center of Excellence in Materials Informatics and UB’s RENEW Institute, an interdisciplinary institute dedicated to solving complex environmental problems.

Solar vapor generator

To conduct the research, the team built a small-scale solar still. The device, which they call a “solar vapor generator,” cleans or desalinates water by using the heat converted from sunlight. Here’s how it works: The sun evaporates the water. During this process, salt, bacteria or other unwanted elements are left behind as the liquid moves into a gaseous state. The water vapor then cools and returns to a liquid state, where it is collected in a separate container without the salt or contaminants.

“People lacking adequate drinking water have employed solar stills for years, however, these devices are inefficient,” says Haomin Song, PhD candidate at UB and one of the study’s leading co-authors. “For example, many devices lose valuable heat energy due to heating the bulk liquid during the evaporation process. Meanwhile, systems that require optical concentrators, such as mirrors and lenses, to concentrate the sunlight are costly.”

The UB-led research team addressed these issues by creating a solar still about the size of mini-refrigerator. It’s made of expanded polystyrene foam (a common plastic that acts as a thermal insulator and, if needed, a flotation device) and porous paper coated in carbon black. Like a napkin, the paper absorbs water, while the carbon black absorbs sunlight and transforms the solar energy into heat used during evaporation.

The solar still coverts water to vapor very efficiently. For example, only 12 percent of the available energy was lost during the evaporation process, a rate the research team believes is unprecedented. The accomplishment is made possible, in part, because the device converts only surface water, which evaporated at 44 degrees Celsius.

Efficient and inexpensive

Based upon test results, researchers believe the still is capable of producing 3 to 10 liters of water per day, which is an improvement over most commercial solar stills of similar size that produce 1 to 5 liters per day.

Materials for the new solar still cost roughly $1.60 per square meter — a number that could decline if the materials were purchased in bulk. (By contrast, systems that use optical concentrators can retail for more than $200 per square meter.) If commercialized, the device’s retail price could ultimately reduce a huge projected funding gap — $26 trillion worldwide between 2010 and 2030, according to the World Economic Forum — needed for water infrastructure upgrades.

“The solar still we are developing would be ideal for small communities, allowing people to generate their own drinking water much like they generate their own power via solar panels on their house roof,” says Zhejun Liu, a visiting scholar at UB, PhD candidate at Fudan University and one the study’s co-authors.

The research was funded, in part, by the U.S. National Science Foundation, the National Science Foundation of China and the Chinese Scholarship Council.


Academics build ultimate solar-powered water purifier - University at Buffalo


Zhejun Liu, Haomin Song, Dengxin Ji, Chenyu Li, Alec Cheney, Youhai Liu, Nan Zhang, Xie Zeng, Borui Chen, Jun Gao, Yuesheng Li, Xiang Liu, Diana Aga, Suhua Jiang, Zongfu Yu, Qiaoqiang Gan. "Extremely Cost-Effective and Efficient Solar Vapor Generation under Nonconcentrated Illumination Using Thermally Isolated Black Paper". Global Challenges (2017). DOI: 10.1002/gch2.201600003

 

[JSCh]

Efficient air filters, hot off the press
30 January 2017

Air filters that greatly reduce air pollution could be mass-produced using materials called metal–organic frameworks (MOFs).

MOFs are porous crystalline materials containing organic ‘struts’ and metal ions, and can capture large amounts of fine particulate matter electrostatically. Bo Wang and his colleagues at the Beijing Institute of Technology heated three kinds of MOF crystals and applied them individually to substrates including fabric, foam and plastic using two hot rollers. In lab tests, the resulting filters reduced the levels of hazardous 2.5- and 10-micrometre-wide particles in air by up to 99.5% at room temperature, with an efficiency drop of only a few per cent at 200 °C.

Potential applications for the filters include household vacuum-cleaner dust bags and vehicle exhaust pipes.


http://www.nature.com/articles/n-12026960?WT.mc_id=TWT_NA_1702_RESEARCHIGHLIGHTS_PORTFOLIO

Yifa Chen, Shenghan Zhang, Sijia Cao, Siqing Li, Fan Chen, Shuai Yuan, Cheng Xu, Junwen Zhou, Xiao Feng, Xiaojie Ma, Bo Wang. Roll-to-Roll Production of Metal-Organic Framework Coatings for Particulate Matter Removal. Adv. Mater. (2017). DOI: 10.1002/adma.201606221

Abstract

A powerful roll-to-roll hot-pressing strategy for mass production of metal-organic framework (MOF)-based filters (MOFilters) using various MOF systems with ranges of substrates is presented. Thus-obtained MOFilters show superior particulate matter removal efficiency under desired working temperatures. Such versatile MOFilters can be scaled up and purposely designed which endow MOFilters with great potentials in both residential and industrial pollution control.​

 

[JSCh]

FEB 02, 2017
Artificial intelligence can diagnose congenital cataract
Nature Biomedical Engineering

Researchers from China have developed an artificial intelligence (AI) platform that can diagnose congenital cataracts as accurately as ophthalmologists.

In a study published in Nature Biomedical Engineering last month, the researchers say that their platform could be applied to other rare diseases in which missed or mistaken diagnoses are common, especially in developing countries with large populations such as China.

Using a database collected under the Childhood Cataract Program of the Chinese Ministry of Health, researchers trained the AI platform, CC-Cruiser, with a dataset of 410 images of congenital cataracts and 476 control healthy eyes, each independently labelled by 2 experienced ophthalmologists.

CC-Cruiser was tested in several complex, real-world settings, including a multihospital clinical trial, a website-based test and a comparative performance test with ophthalmologists.

The comparative test involved 50 cases of various challenging clinical situations, evaluated independently by CC-Cruiser and ophthalmologists with 3 levels of expertise: expert, competent and novice.

The CC-Cruiser successfully diagnosed all congenital cataract cases, while ophthalmologists at all expertise levels missed several cases and misdiagnosed several false positives. The device also successfully suggested treatment, correctly identifying all the patients in need of surgery, with just 5 false positives.

"Humans tend to be [either] somewhat conservative or radical due to their own experience and personality, and the machine's advantage is its objectivity," said coauthor, Professor Lin Haotian of Sun Yat-Sen University. "We [believe] that deep learning results collaborating with human analysis will achieve a better health care quality and efficiency."

Encouraged by the results, Lin and his team have built a collaborative cloud platform that can be accessed by doctors at hospitals around the country, allowing them to upload patient images into the system. CC-Cruiser will benefit from the continued data collection, further improving the AI platform with a larger dataset.

"The limited resources of patients and the isolation of the data in individual hospitals represent a bottleneck in data usage," Lin said. "Building a collaborative cloud platform for data integration and patient screening is an essential step."


Artificial intelligence can diagnose congenital cataract - American Academy of Ophthalmology

Erping Long et al. An artificial intelligence platform for the multihospital collaborative management of congenital cataracts, Nature Biomedical Engineering (2017). DOI: 10.1038/s41551-016-0024

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[艹艹艹]

 

[JSCh]

British, Chinese scientists make breakthrough in 21st century killers research
Source: Xinhua 2017-02-09 03:07:06

LONDON, Feb. 8 (Xinhua) -- Scientists in Manchester revealed Wednesday they and their Chinese colleagues had found a new avenue to explore in the search for the causes of neurodegenerative diseases that are becoming big killers in the 21st century.

Disabling a part of brain cells that act as a tap to regulate the flow of proteins has been shown to cause neurodegeneration, a new study has found, the University of Manchester reported.

Lead researcher Professor Martin Lowe told Xinhua: "Our findings provide new insight into the mechanisms that cause death of nerve cells within the brain, and are relevant for our understanding of neurodegenerative diseases such as ataxia, Parkinson's, and Alzheimer's disease."

"This improved understanding may be exploited in the future to develop novel therapies for these devastating conditions," Lowe said.

He said that turning off the protein tap in the brain provided a new clue to neurodegenerative diseases.

The study was carried out by the University of Manchester and the Shilai Bao lab at the Chinese Academy of Sciences in Beijing.

The research, which was carried out in mice, focused on the Golgi apparatus, a compartment inside all cells in the body that control the processing and transport of proteins. It is fundamental for the growth of the cell membrane and also for the release of many types of proteins such as hormones, neurotransmitters, and the proteins that make up human skeletons.

Working with Chinese colleagues, the Manchester researchers examined the role of the Golgi apparatus in brain cells and found that mice in which the apparatus was disabled suffered from developmental delay, severe ataxia, and postnatal death.

Ataxia is a term for a group of disorders that affect co-ordination, balance and speech. Any part of the body can be affected, but people with ataxia often have difficulties with balance and walking, speaking, swallowing, tasks such as writing and eating, and vision. It can be inherited, brought on through incidents such as a stroke, or through old age.

"Although the function of the Golgi apparatus, named after its Italian discoverer, is well understood, it has not been previously been shown to have a role in neurodegeneration. With these results, the scientists think they may have found a new avenue to explore in the search for the causes of some neurodegenerative diseases," Lowe said.

"Our results, combined with previous work, suggest that during the cellular changes that occur, loss of the Golgi function could be an important intermediary step that contributes to cell death," Lowe added. "Our findings suggest that in certain neurodegenerative diseases the loss of function of the Golgi apparatus may contribute to the pathology that is occurring."