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Even unsweetened drinks are acidic and should not be drunk between meals, researchers say.
The lab-grown versions made from a patient’s cancer can predict whether drugs will actually work.
The global fishing fleet is so big it can be seen from space. Really.
Fishing activity now covers at least 55 percent of the world’s oceans — four times the land area covered by agriculture — and can now be monitored, in near real time, to the level of individual vessels. In fact, 70,000 vessels of the global fishing fleet traveled 460 million kilometers in 2016, equivalent to traveling to the moon and back 600 times.
Using satellite tracking, machine learning and common ship-tracking technology, scientists from UC Santa Barbara teamed up with colleagues at Global Fishing Watch, National Geographic Society’s Pristine Sea project, Dalhousie University, SkyTruth, Google and Stanford University to illuminate the extent of global fishing — down to single vessel movements and hourly activity. Their findings appear in the journal Science.
“I think most people will be surprised that until now we didn’t really know where people were fishing in vast swaths of the ocean,” said co-author Christopher Costello, a professor at UCSB’s Bren School of Environmental Science & Management. “This new real-time dataset will be instrumental in designing improved management of the world’s oceans that is good for the fish, ecosystems and fishermen.”
While the dataset is hundreds of times higher in resolution than previous global surveys, the total area of the ocean fished is likely higher than the 55 percent estimated. That’s because some fishing efforts in regions of poor satellite coverage or in exclusive economic zones with a low percentage of vessels using the automatic identification system (AIS) were not included.
The team used machine learning technology to analyze 22 billion messages publicly broadcasted from vessels’ AIS positions from 2012 to 2016, to answer the question, “What drives commercial fishing behavior?” Based solely on vessel movement patterns, the Global Fishing Watch algorithm was able to identify more than 70,000 commercial fishing vessels, the sizes and engine powers of these vessels, what type of fishing they engaged in, and when and where they fished down to the hour and kilometer.
This new global view of fishing draws on advances in satellite technology and big data processing.
More than 40 million hours of fishing activity was observed in 2016, and while most nations appeared to fish predominantly within their own exclusive economic zones, China, Spain, Taiwan, Japan and South Korea accounted for 85 percent of the observed fishing on the high seas.
“This dataset provides such high-level resolution on fishing activity that we can even see cultural patterns, such as when fishermen in different regions take time off,” said co-author Juan Mayorga, a project scientist in the Sustainable Fisheries Group at the Bren School and with NatGeo’s Pristine Seas. For example, in the Chinese fishing fleet — the largest in the world — during Chinese New Year fishing activity is reduced to levels comparable to those during seasonal bans enforced by the government.
The investigative team also found that when and where fishing occurs are tied more to politics and culture than to natural cycles such as fish migrations and marine food production. “Our analysis demonstrated that policies, cultures and economics play a huge role in driving fishing behavior,” Costello said.
“In addition, we examined whether fishing diminished when fuel prices were high and found a weak response,” he added. “These are the kinds of things about which we’ve always speculated but haven’t ever been able to test — until now.”
The resulting interactive map — which is freely available to the public — shows a near real-time view of the fishing patterns of individual vessels and fleets. This allows anyone to see what is going on in their own backyard and to observe where policy boundaries are in place and where they are not.
“By making this data public, we are providing governments, management bodies and researchers with the information needed to make transparent and well-informed decisions to better regulate fishing activities and reach conservation and sustainability goals,” Mayorga said.
The study not only opens a gateway for improved ocean management but also confirms that fishing activity is clearly bounded according to differing management regimes, which indicates the role that well-enforced policy can play in curbing overexploitation.
“This collaboration opens up myriad research opportunities,” Costello explained. “We are leveraging the products developed by Global Fishing Watch to address new and important research questions that will improve fisheries sustainability around the world.”
Researchers from CIC nanoGUNE (San Sebastian, Spain), in collaboration with the Donostia International Physics Center (DIPC, San Sebastian, Spain) and Kansas State University (USA), report in Science the development of a so called ‘hyperbolic metasurface’ on which light propagates with completely reshaped wavefronts. This scientific achievement towards a more precise control and monitoring of light is highly interesting for the long run technological challenge of miniaturizing optical devices for sensing and signal processing.
Optical waves propagating away from a point source typically exhibit circular (convex) wavefronts. “Like waves on a water surface when a stone is dropped,” explains Peining Li, EU Marie Sklodowska-Curie fellow at nanoGUNE and first author of the paper. The reason of this circular propagation is that the medium through which light travels is typically homogenous and isotropic i.e. uniform in all directions.
Scientists had already theoretically predicted that specifically structured surfaces can turn the wavefronts of light upside down when it propagates along them. “On such surfaces, called hyberbolic metasurfaces, the waves emitted from a point source propagate only in certain directions and with open (concave) wavefronts,” explains Javier Alfaro, PhD student at nanoGUNE and co-author of the paper. These unusual waves are called hyperbolic surface polaritons. Because they propagate only in certain directions, and with wavelengths that are much smaller than that of light in free space or standard waveguides, they could help to miniaturize optical devices for sensing and signal processing.
Now, the researchers developed such a metasurface for infrared light. It is based on boron nitride, a graphene-like 2D material, and was selected because of its capability to manipulate infrared light on extremely small length scales, which could be applied for the development of miniaturized chemical sensors or for heat management in nanoscale optoelectronic devices. On the other hand, the researchers succeeded to directly observe the concave wavefronts with a special optical microscope, which have been elusive so far.
Hyperbolic metasurfaces are challenging to fabricate because an extremely precise structuring on the nanometer scale is required. Irene Dolado, PhD student at nanoGUNE, and Saül Vélez, former postdoctoral researcher at nanoGUNE (now at ETH Zürich) mastered this challenge by electron beam lithography and etching of thin flakes of high-quality boron nitride provided by Kansas State University. “After several optimization steps, we achieved the required precision and obtained grating structures with gap sizes as small as 25 nm,” Dolado says. “The same fabrication methods can also be applied to other materials, which could pave the way to realize artificial metasurface structures with custom-made optical properties,” adds Saül Vélez.
To see how the waves propagate along the metasurface, the researchers used a state-of the-art infrared nanoimaging technique that was pioneered by the nanoptics group at nanoGUNE. They first placed an infrared gold nanorod onto the metasurface. “It plays the role of a stone dropped into water,” says Peining Li. The nanorod concentrates incident infrared light into a tiny spot, which launches waves that then propagate along the metasurface. With the help of a so-called scattering-type scanning near-field microscope (s-SNOM) the researchers imaged the waves. “It was amazing to see the images. They indeed showed the concave curvature of the wavefronts that were propagating away form the gold nanorod, exactly as predicted by theory,” says Rainer Hillenbrand, Ikerbasque Professor at nanoGUNE, who led the work.
The results promise nanostructured 2D materials to become a novel platform for hyberbolic metasurface devices and circuits, and further demonstrate how near-field microscopy can be applied to unveil exotic optical phenomena in anisotropic materials and for verifying new metasurface design principles.
The research has been mainly funded by individual fellowship grants of the European Union Marie Sklodowsca-Curie Actions and the pre-doctoral research grants program of the Basque and Spanish Governments, as well as by the National Science Foundation (USA), and has been carried out in line with nanoGUNEs projects within the EU’s Graphene Flagship.
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Using an innovative crystallization technique for studying three-dimensional structures of gene transcription machinery, an international team of researchers, led by scientists at Penn State, has revealed new insights into the long debated action of the “magic spot” — a molecule that controls gene expression in Eschericahia coli and many other bacteria when the bacteria are stressed. The study contributes to our fundamental understanding of how bacteria adapt and survive under adverse conditions and provides clues about key processes that could be targeted in the search for new antibiotics. A paper describing the research appears on February 22, 2018 in the journal Molecular Cell.
“When bacteria experience stress, such as starvation, they remodel their gene expression,” said Katsuhiko Murakami, professor of biochemistry and molecular biology at Penn State and an author of the paper. “In 1969, our coauthor, Michael Cashel, discovered that a new molecule appeared in E. coli when the bacteria were starved of key nutrients. Cashel called this molecule, which showed up as a new spot on a chromatogram, the ‘magic spot,’ because of its appearance from seemingly nowhere when bacteria were starved.”
The magic spot subsequently was shown to be guanosine tetraphosphate, or ppGpp, a chemically modified analog of the G nucleotide in the ATCG alphabet of the genome. Its appearance following starvation and other stresses is associated with changes in the expression of over 500 genes, most prominently genes for the structural RNAs that are components of the ribosome — the enzyme responsible for protein synthesis.
The ppGpp molecule interacts with E. coli‘s RNA polymerase — the cellular machine that produces RNA from genomic DNA — but precisely how this interaction controls gene expression remains a mystery. The new X-ray crystal structures, however, provide clues to this process by showing for the first time three-dimensional images of E. coli RNA polymerase in complex with ppGpp and another important factor that works with ppGpp, DksA.
The three-dimensional structure of RNA polymerase is well established, but seeing the structure of RNA polymerase while it is interacting with other molecules has proved to be technically difficult. The interacting molecules often disassociate during the crystallization process necessary to see their structure. The researchers overcame this difficulty by adding molecules of DksA and ppGpp to RNA polymerase that had been crystalized independently.
“We first created crystals of RNA polymerase, then soaked in DksA and ppGpp,” said Vadim Molodtsov, assistant research professor in biochemistry and molecular biology at Penn State and another author of the paper. “When we did this, we saw that ppGpp bound to the complex of RNA polymerase and DksA in a way that changed the interaction between RNA polymerase and DksA. We think this change could be key to explain how ppGpp alters transcription so that the bacteria can respond to stress.”
RNA polymerase in bacteria controls the expression of all genes, but in response to the presence of ppGpp, the expression levels of some genes are turned down, while many are unaffected and some are turned up. These changes in expression levels allow the bacteria to alter their composition to better survive stress. The researchers speculate that the different responses may be due to individual differences in the promotors — DNA sequences near the beginnings of genes that initiate expression — of individual genes.
“We are full of bacteria,” said Sarah Ades, associate professor of biochemistry and molecular biology at Penn State and an author of the paper. “They affect our mood, they affect our weight, they affect our immune systems. The ppGpp system is important in lots of these bacteria, allowing them to sense their environment and adjust to stress. Understanding how ppGpp functions will allow us to better understand these bacteria and how they affect us. The system is also important in bacterial pathogens that cause infectious disease. Understanding how ppGpp works could allow us to find ways to disrupt its functions and develop new antibiotics.”
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Should doctors continue to hand over names and addresses to immigration officers, asks the NHS in England.
One 12-year-old boy had to have part of his bowel removed after swallowing the magnetic balls.
For Banetsi Andreas Mphunga, who turned his counselling practice into therapy on wheels, there’s only one rule: never stop moving.
This wasn’t his calling, the professor told him. And on paper, maybe he was right: Banetsi was trailing at the bottom of his class, struggling despite hours spent studying and agonising over his papers and tests.
But Banetsi was equal parts stubborn and certain that psychology was the way he wanted to make a difference. And he also believed he had something nobody else had: a resilient, unbreakable entrepreneurial spirit.
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Now, he’s the counsellor on wheels, a man who ditched the safety net of a full-time job and sank his money into a Kombi to travel into impoverished communities, helping people who had given up on help a long time ago.
He’s making waves, but he’s only getting started. His endgame is to peel away the stigma around mental illness and life-saving therapy, one kilometre at a time.
There were drugs. Lots of them. And as a teenager in Khayelitsha, Banetsi tried them all.
“I was a typical kid in the township,” he says. “I know what dagga tastes like, and what mandrax tastes like too.”
But unlike his friends, many who had to return to broken and abusive households, Banetsi’s home was a safe sanctuary, guarded by disciplined, inspirational and supportive women.
His mother and sisters gave him the room and independence to make his own mistakes – in the aftermath of which he wouldn’t be chided, beaten or ostracised, but told where he had gone wrong, and how to correct his course.
The ‘Wheel’ Deal: Banetsi Andreas Mphunga modified an old Kombi to house his colourful mobile counselling room. The dream: taking his practice cross country
“And so with the drugs, for example, when I saw things were going too far, that I was going to be burnt, I had the ability to see that I was heading down a dangerous path, and I pulled back,” he says.
Read more: This guy jumped off a roof to save a man’s life
When Banetsi finished school, he was certain he wanted to be an architect. But after numerous rejected applications, he settled on studying oceanography. It turned out to be a huge mistake – he was miserable. After three, unsatisfying and arduous months, he turned to his sisters.
“I told them I wanted to drop out,” he says. They were supportive – even taking him to a psychologist, who recommended he study a new field. The session was instrumental in clearing his mind, helping him see a path he hadn’t even considered: becoming a psychologist himself.
“I had done an internship at the Department of Social Development before that, and I had enjoyed what I was doing there: the interventions, the work… it was very rewarding,” he says.
He applied to study psychology at the University of the Western Cape. During his third year, a professor pulled him aside. “This course isn’t for you,” he told the passionate student. “Why don’t you go and do something easier?”
At the time, Banetsi was struggling. His official transcript was dotted with plummeting grades. But giving up now wasn’t an option. The young student had a vision: he wanted to help people in a way he knew nobody else could.
And part of him wanted to prove people wrong, to show them that it wasn’t just about numbers on a piece of paper, that his mission was bigger than all of this. He stuck it out.
When he passed, that same professor said to him: “When you entered this room, you entered as my student. When you leave, you leave as my colleague.” Banetsi was floored. He had to sit down.
To date, it’s still his proudest moment – a payoff for the years he spent believing in himself, despite languishing at the bottom of his class. He would need to tap into that energy after university, as he struggled to find work.
“I searched like nobody’s business,” he laughs. “But no luck.”
Read more: Risefrom the ashes: the story of long jumper Luvo Manyonga
He ended up volunteering in Khayelitsha, doing a job that had nothing to do with his degree. It turned out to be an invaluable move, bringing him back to the ground level of the issues running rampant in the township.
Between the addiction, crime, abuse, gangsterism, teen pregnancy and broken households, it was clear that urgent intervention was required.
“I thought to myself, how can I help these people?” he says.
That’s when he bought the Kombi, reworking the van’s innards to resemble the confines of a counselling room. He brought psychological help right to people’s doorsteps, a quick step to climb over the intense stigma around mental health and help. It’s difficult and expensive but rewarding work.
He’s working with people who suffer every day and night, who see no way out. And he gives them hope, the tools to cope with their struggles. He works with rape victims, gangsters, drug addicts, abusive fathers, abused mothers.
“It’s draining, sometimes,” he says. “When I go to see my supervisor, the debriefing process I go through is so intense. I’m one person, and I sometimes have to carry so much.”
But he sees changes, and that makes it worth it. Just recently he helped a violent father overcome decades of anger and finally find peace, using a colouring book to overcome the man’s tough exterior.
“These townships have been ruined by our history, and we still have a backlog of issues that haven’t been resolved. There are no psychologists out here, or in the rural townships in the Eastern Cape, or Limpopo, or the Northern Cape; and we need them here most.”
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Banetsi wants to travel the country. But for now, he has to figure out how to pay for that. A week on the road would break the bank. Months? Not possible – yet.
“Yes, the Kombi is broken down right now,” he says. “But I will fix it. I will find a way to do this – with help, or all by myself.”
This article was originally published on www.mh.co.za
Image credits: Igor Polzenhagen
Scientists hail “good news for patients” as analysis finds 21 drugs reduce symptoms of depression.
