Tech

To solve a problem, you must first see the problem. More than that, whatever fallout the problem is causing must be controlled while you solve it. That's the approach an international team of researchers has taken for combatting network attacks. They published their results in IEEE/CAA Journal of Automatica Sinica.

"The communication network and the physical system in a networked control system are vulnerable to potential malicious attacks--including jamming, replay and others," said Dr. Chandreyee Bhowmick, Department of Electrical and Computer Engineering at the Missouri University of Science and Technology.

"One common attribute of all these attacks is that they all tend to deviate the traffic flow in the communications links from the normal value, thus increasing network-induced delays and packet losses."

Bhowmick and colleagues developed a hybrid learning approach to not only detect attacks, but to compensate for the issues the attacks cause. According to Bhowmick, many cyber-attacks target information availability rather than data secrecy.

"For such attacks, even the most complicated encryption algorithms fail," Bhowmick said. "To address this issue, in this study, we developed novel attack detection and estimation schemes by using a learning approach that captures the vulnerable communication links, which is challenging because the state matrix is unknown."

The state matrix is the state of the system, which includes the speed and type of information flow. A system under attack has even more unpredictable information flow, or lack thereof. In Bhowmick's proposed scheme, an adaptive observer can detect the onset of attacks and learns how the attacks are disrupting the system. This allows the system to react and perform optimally, even under duress.

However, the proposed method isn't perfect, and the researchers plan to fine-tune their approach to operate in even more complicated attacks.

"Although this approach can detect a broad range of t attacks on both the network and the physical system, detection of sophisticated attacks remains the scope of future work," Bhowmick said. "Studying the signature of such attacks and using probabilistic approach to detect them is one of the prospects of future work."

When it comes to playing a game of fetch, many dogs are naturals. But now, researchers report that the remarkable ability to interpret human social communicative cues that enables a dog to go for a ball and then bring it back also exists in wolves. The study appears January 16 in the journal iScience.

The findings were made serendipitously when researchers tested 13 wolf puppies from three different litters in a behavioral test battery designed to assess various behaviors in young dog puppies. During this series of tests, three 8-week-old wolf puppies spontaneously showed interest in a ball and returned it to a perfect stranger upon encouragement. The discovery comes as a surprise because it had been hypothesized that the cognitive abilities necessary to understand cues given by a human, such as those required for a game of fetch, arose in dogs only after humans domesticated them at least 15,000 years ago.

"When I saw the first wolf puppy retrieving the ball I literally got goose bumps," says Christina Hansen Wheat of Stockholm University, Sweden. "It was so unexpected, and I immediately knew that this meant that if variation in human-directed play behavior exists in wolves, this behavior could have been a potential target for early selective pressures exerted during dog domestication."

Hansen Wheat is interested in understanding how domestication affects behavior. To study this, she and her team raise wolf and dog puppies from the age of 10 days and put them through various behavioral tests. In one of those tests, a person the pup does not know throws a tennis ball across the room and, without the benefit of any prior experience or training, encourages the puppy to get it and bring it back.

The researchers never really expected wolf pups to catch on. In fact, the first two wolf litters they worked with showed little to no interest in balls let alone retrieving one. They thought little of it at the time. It was what they would have expected, after all. That is until they tested the third wolf litter and some of the puppies not only went for the ball, but also responded to the social cues given by the unfamiliar person and brought it back.

"It was very surprising that we had wolves actually retrieving the ball," says Hansen Wheat. "I did not expect that. I do not think any of us did. It was especially surprising that the wolves retrieved the ball for a person they had never met before."

Hansen Wheat adds that similarities between dogs and wolves can tell us something about where the behavior we see in our dogs comes from. And, while it was a surprise to see a wolf puppy playing fetch and connecting with a person in that way, she says, in retrospect, it also makes sense.

"Wolf puppies showing human-directed behavior could have had a selective advantage in early stages of dog domestication," she says.

Her team will now continue to work with the data they have collected over the course of three years hand-raising wolves and dogs under identical conditions to learn even more about their behavioral differences and similarities.

Taenia solium--also called pork tapeworm--is a parasite which causes disease around the world, particularly in very poor communities with deficient santiation and where pigs roam free. Researchers have now analyzed the efficacy and adverse effects of three chemotherapeutics against T. solium and report their results in a review published in PLOS Neglected Tropical Diseases.

In its adult form, T. solium causes an intestinal infection known as taeniasis. Humans can become infected with taeniasis when they eat raw or undercooked, infected pork that contains T. solium larvae. A cysticerci form of disease can also develop when humans or pigs ingest the tapeworm eggs; this form can lead to muscle and central nervous system symptoms including seizures (epilepsy if they are recurrent). In endemic countries, T. solium can be responsible for approximately 30% of epilepsy cases. However, in specific communities this can be up to 70%.

In the new work, Michelle Haby of the University of Sonora, Mexico, and colleagues reviewed existing literature on three existing deworming drugs which have shown some efficacy in treating taeniasis. The drugs are albendazole (ALB), praziquantel (PZQ) and niclosamide (NICL). 20 studies met the inclusion criteria for the review; 11 used a before-after study design while 9 were controlled trials. The drug tested was ALB in 7 studies, NICL in 4 studies, PZQ in 7 studies, and a combination of PZQ and NICL in two studies.

Meta-analysis showed that a single dose of PZQ 10 mg/kg cured 99.5% of T. solium taeniasis; ALB 400 mg per day for three consecutive days led to a 96.4% cure rate; and NICL 2g led to a 84.3% cure rate. Less effective were PZQ 5mg/kg, with a 89.0% cure rate, and a single dose of ALB 400 mg, with a 52.0% cure rate. Most studies reported no or only mild and transient side effects following administration of the drugs.

The drugs "were effective as taenicides and could be considered for use in mass drug administration programs for the control of T. solium taeniasis," the researchers say. "Future efficacy research should focus on the conduct of high quality randomized controlled trials of the three different drugs and varying doses, both in comparison to placebo and in head-to-head trials."

WASHINGTON -- Researchers have harnessed the power of a type of artificial intelligence known as deep learning to create a new laser-based system that can image around corners in real time. With further development, the system might let self-driving cars "look" around parked cars or busy intersections to see hazards or pedestrians. It could also be installed on satellites and spacecraft for tasks such as capturing images inside a cave on an asteroid.

"Compared to other approaches, our non-line-of-sight imaging system provides uniquely high resolutions and imaging speeds," said research team leader Christopher A. Metzler from Stanford University and Rice University. "These attributes enable applications that wouldn't otherwise be possible, such as reading the license plate of a hidden car as it is driving or reading a badge worn by someone walking on the other side of a corner."

In Optica, The Optical Society's journal for high-impact research, Metzler and colleagues from Princeton University, Southern Methodist University, and Rice University report that the new system can distinguish submillimeter details of a hidden object from 1 meter away. The system is designed to image small objects at very high resolutions but can be combined with other imaging systems that produce low-resolution room-sized reconstructions.

"Non-line-of-sight imaging has important applications in medical imaging, navigation, robotics and defense," said co-author Felix Heide from Princeton University. "Our work takes a step toward enabling its use in a variety of such applications."

Solving an optics problem with deep learning

The new imaging system uses a commercially available camera sensor and a powerful, but otherwise standard, laser source that is similar to the one found in a laser pointer. The laser beam bounces off a visible wall onto the hidden object and then back onto the wall, creating an interference pattern known as a speckle pattern that encodes the shape of the hidden object.

Reconstructing the hidden object from the speckle pattern requires solving a challenging computational problem. Short exposure times are necessary for real-time imaging but produce too much noise for existing algorithms to work. To solve this problem, the researchers turned to deep learning.

"Compared to other approaches for non-line-of-sight imaging, our deep learning algorithm is far more robust to noise and thus can operate with much shorter exposure times," said co-author Prasanna Rangarajan from Southern Methodist University. "By accurately characterizing the noise, we were able to synthesize data to train the algorithm to solve the reconstruction problem using deep learning without having to capture costly experimental training data."

Seeing around corners

The researchers tested the new technique by reconstructing images of 1-centimeter-tall letters and numbers hidden behind a corner using an imaging setup about 1 meter from the wall. Using an exposure length of a quarter of a second, the approach produced reconstructions with a resolution of 300 microns.

The research is part of DARPA's Revolutionary Enhancement of Visibility by Exploiting Active Light-fields (REVEAL) program, which is developing a variety of different techniques to image hidden objects around corners. The researchers are now working to make the system practical for more applications by extending the field of view so that it can reconstruct larger objects.

Dragonflies and damselflies are animals that may appear gentle but are, in fact, ancient hunters. The closely related insects shared an ancestor over 250 million years ago -- long before dinosaurs -- and provide a glimpse into how an ancient neural system controlled precise and swift aerial assaults.

A paper recently published in Current Biology, led by University of Minnesota researchers, shows that despite the distinct hunting strategies of dragonflies and damselflies, the two groups share key neurons in the circuit that drives the hunting flight. These neurons are so similar, researchers believe the insects inherited them from their shared ancestor and that the neurons haven't changed much.

Gaining insight into their ability to quickly process images could inform technological advancements. These findings could inform where to mount cameras on drones and autonomous vehicles, and how to process the incoming information quickly and efficiently.

"Dragonflies and damselflies are interesting from an evolutionary point of view because they give us a window into ancient neural systems," said Paloma Gonzalez-Bellido, assistant professor in the Department of Ecology, Evolution and Behavior in the College of Biological Sciences and senior author on the paper. "And because there are so many species, we can study their behavior and compare their neural performance. You can't get that from fossils."

A noticeable difference between dragonflies and damselflies is the shape and position of their eyes. Most dragonflies today have eyes that are close together, often touching along the top of their head. Whereas damselflies sport eyes that are far apart. The researchers wanted to know whether this made a difference in their hunting habits, and if it affected how their neural system detects moving prey.

Researchers found:

dragonflies and damselflies hunt prey differently, with dragonflies using a higher resolution area near the top of their eyes to hunt prey from below and damselflies leveraging increased resolution in the front of their eyes to hunt prey in front of them;

in dragonflies with eyes that merge at the top, the eyes work as if they were two screens of an extended display (i.e. the image of the prey, which would be equivalent to the mouse pointer, can fall on either the left or the right, but never in both screens at the same time);

damselflies eyes work as duplicated screens, where the prey image is seen by both eyes at once (i.e. they have binocular vision);

both designs have pros and cons, and their presence correlates with the type of prey and the environment;

despite different strategies, the neurons that transfer information about a moving target from the brain to the wing motor centers are nearly identical in the two groups -- indicating they were inherited from the common ancestor.

The different hunting strategies pay off in different environments. Dragonflies tend to hunt in an open area, leveraging the contrast of the sky to help them spot their target. Although they can't calculate depth using two images, they rely on other cues. Damselflies tend to hunt among vegetation, where the selective pressure for fast reaction may be absent, or the need for depth perception stronger.

Researchers are now looking to understand how the extended versus duplicated images are calculated in the brain, and how the information is implemented into muscle movements.

"There is still a lot we do not understand," said Jack Supple, first author and a recent PhD graduate from Gonzalez-Bellidos laboratory. "We do not know how these neurons coordinate all the different muscles in the body during flight. If we tried to build a realistic robotic damselfly or dragonfly tomorrow we would have a difficult time."

In addition to examining the differences amongst the two insect families, researchers continue to explore differences in species within each family. "While most dragonflies have eyes close together, there are a handful of species with eyes far apart," said Gonzalez-Bellido. "Some of them are abundant in Minnesota and we are eager to leverage the new flight arena to study their behavior in a controlled setting."

Researchers aim to collect at Cedar Creek Ecosystem Science Reserve and Itasca Biological Station and Laboratories this summer, both areas with diverse populations of dragonflies and damselflies.

Boston, MA -- In 2017, for every victim who died of a firearm injury in the U.S, three individuals survived. But the burden of firearm injuries is not limited to death. A new study led by investigators from Brigham and Women's Hospital finds that 6-to-12 months after traumatic injury, rates of chronic pain, post-traumatic stress disorder (PTSD) and other poor physical and mental health outcomes were alarmingly high among survivors of firearm violence -- even higher than among survivors who had sustained similar injuries in motor vehicle crashes. The study, which highlights the need for following survivors after discharge and providing continued care, is published in Annals of Surgery.

"When it comes to the public health problem posed by firearm injury, death is just one piece of the puzzle," said corresponding author Juan P. Herrera-Escobar, MD, MPH, the research director of Long-Term Outcomes in Trauma in the Center for Surgery and Public Health at the Brigham. "Mortality rates for trauma patients have been dropping significantly over the last 20 years, but this presents a new challenge: What will we do for patients whose lives we save but who continue to suffer from the repercussions of traumatic injury? Our study shows that injury, and especially firearm injury, casts a long shadow over the lives of those who survive."

As part of the Functional Outcomes and Recovery after Trauma Emergencies (FORTE) project, Herrera-Escobar and colleagues from the Center for Surgery and Public Health surveyed adults who had survived traumatic injury after being treated at one of three level-I trauma centers in Boston between 2015-2018. FORTE is intended to measure long-term outcomes that are meaningful to patients and their families, including functional status, health-related quality of life, treatment adherence, and more.

Of 177 eligible firearm injury survivors, 100 were successfully contacted and 63 completed the survey. This response rate of 35 percent was much higher than in previous studies of firearm injury survivors.

The team analyzed outcomes for people who had survived firearm injury and compared these outcomes to people who had survived similar injuries sustained in motor vehicle crashes. All survivors were surveyed as part of the FORTE project. Among survivors of firearm injury, 68 percent reported daily pain, 53 percent screened positive for PTSD, 39 percent reported a new functional limitation in an activity of daily living (such as walking, cooking, eating or going to the bathroom), and 59 percent had not returned to work. Three-out-of-four firearm injury survivors had at least one of these negative long-term outcomes.

Not only were these rates significantly higher than rates among the general population, survivors of firearm injury were significantly more likely to have daily pain or PTSD, and worse physical and mental health-related quality-of-life than survivors with similar injuries from motor vehicle crashes.

The authors note that given that their analysis was done at three urban trauma centers in Boston, their findings may or may not be generalizable to the rest of the U.S. As with all survey-based studies, the study may also be limited by selection bias and recall bias as well as a lack of baseline information about those surveyed.

According to Herrera-Escobar, he and his colleagues have just begun to scratch the surface and many more questions remain.

"We need to better understand the causes of these outcomes so that we can find opportunities for intervention," he said. "This work has profound implications for trauma systems and highlights the failure to help patients receive the proper services for a successful recovery after a traumatic, firearm-related injury."

New Haven, Conn. -- Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers. It was all about the asteroid.

In a break from a number of other recent studies, Yale assistant professor of geology & geophysics Pincelli Hull and her colleagues argue in a new research paper in Science that environmental impacts from massive volcanic eruptions in India in the region known as the Deccan Traps happened well before the Cretaceous-Paleogene extinction event 66 million years ago and therefore did not contribute to the mass extinction.

Most scientists acknowledge that the mass extinction event, also known as K-Pg, occurred after an asteroid slammed into Earth. Some researchers also have focused on the role of volcanoes in K-Pg due to indications that volcanic activity happened around the same time.

"Volcanoes can drive mass extinctions because they release lots of gases, like SO2 and CO2, that can alter the climate and acidify the world," said Hull, lead author of the new study. "But recent work has focused on the timing of lava eruption rather than gas release."

To pinpoint the timing of volcanic gas emission, Hull and her colleagues compared global temperature change and the carbon isotopes (an isotope is an atom with a higher or lower number of neutrons than normal) from marine fossils with models of the climatic effect of CO2 release. They concluded that most of the gas release happened well before the asteroid impact -- and that the asteroid was the sole driver of extinction.

"Volcanic activity in the late Cretaceous caused a gradual global warming event of about two degrees, but not mass extinction," said former Yale researcher Michael Henehan, who compiled the temperature records for the study. "A number of species moved toward the North and South poles but moved back well before the asteroid impact."

Added Hull, "A lot of people have speculated that volcanoes mattered to K-Pg, and we're saying, 'No, they didn't.'"

Recent work on the Deccan Traps, in India, has also pointed to massive eruptions in the immediate aftermath of the K-Pg mass extinction. These results have puzzled scientists because there is no warming event to match. The new study suggests an answer to this puzzle, as well.

"The K-Pg extinction was a mass extinction and this profoundly altered the global carbon cycle," said Yale postdoctoral associate Donald Penman, the study's modeler. "Our results show that these changes would allow the ocean to absorb an enormous amount of CO2 on long time scales -- perhaps hiding the warming effects of volcanism in the aftermath of the event."

The Gouti lab from the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC) has developed functional neuromuscular organoids (NMOs) that self-organize into spinal cord neurons and muscle tissue. Together the two cell types form a complex neuronal network that directs muscle tissue to contract. The neuromuscular organoids, described in the journal Cell Stem Cell, represent a breakthrough for the study of human neuromuscular system development and disease.

The control of body movement is achieved by a complex neuromuscular network that includes the generation of rhythmic patterns of neuronal activity essential for locomotion. Defects in this network are the cause of incurable neuromuscular diseases that result in paralysis and death. Studying the diseases that affect this system has been difficult due to the limited availability of reliable human cell culture models.

There are several unique features that make these organoids a particularly attractive model for neuromuscular development and disease. A key feature is the development of functional neuromuscular junctions, which transmit signals that are essential for movement. Neuromuscular organoids are the first example where spinal cord neurons, skeletal muscles and Schwann cells co-develop from the same progenitor cells and form functional neuromuscular junctions. Furthermore, the organoids developed a complex circuitry that mimics central pattern generator (CPG) circuits, which produce oscillating, rhythmic signals critical for breathing and walking.

"Our initial goal was to develop functional neuromuscular junctions, but the findings exceeded our expectations because the additional development of the CPG-like networks was an exciting but unexpected finding," said Dr. Mina Gouti, who heads MDC's Stem Cell Modeling of Development and Disease Lab. "This has not been shown in a human in vitro model before, and offers entirely novel possibilities, including the study of CPG involvement in neurodegenerative diseases."

The two-in-one challenge

Organoids are miniature, simplified organ-like structures grown in the lab. While techniques for developing organoids for different tissues have advanced in the past decade, it has remained a significant challenge to simultaneously grow two different tissue types into a single functional organoid. For example, to study human neuromuscular junctions, spinal cord neurons and muscles have initially been grown separately and later combined and allowed to interact. In that approach, junctions indeed formed but showed limited functionality and part of the reason was the absence of the all-important Schwann cells.

"It is very limiting if you only have an enriched system for neurons or muscles and then combine them," said Jorge-Miguel Faustino Martins, first author and a bioengineering PhD student in Gouti's lab. "It doesn't really mimic what happens in the embryo where you have both systems developing simultaneously. By combining the potential of stem cells with the powerful organoid technology, neuromuscular organoids present an exciting model to study neuromuscular diseases as well as a robust model for developmental studies where the formation of complex neuromuscular circuitry can be analyzed in real time in 3D microenvironment closer to the one present in the embryo."

The importance of the right progenitor cell type

To overcome this challenge, Gouti and her colleagues followed up on their earlier findings that allowed the conversion of human pluripotent stem cells into axial stem cells, which are known to give rise to both the spinal cord and skeletal muscle during normal embryonic development. They turned the stem cells into the desired type of axial stem cells, called neuromesodermal progenitor cells.

When the axial stem cells were placed in a 3D cell culture, they differentiated and self-organized into complex structures comprising spinal cord neurons and skeletal muscle tissue. This resulted in the development of functional neuromuscular junctions containing terminal Schwann cells, and the formation of complex spinal neural networks similar to central pattern generators (CPG).

"It is striking that the two different tissues can self-organize in 3D and develop advanced functional networks," Gouti said. "These organoids started contracting after 40 days in culture. This activity was driven by the release of neurotransmitter acetylcholine from the resident motor neurons in the organoid and was not due to spontaneous muscle activity seen in other systems. We were able to show that, because pharmacological blocking of the acetylcholine receptors was sufficient to abolish muscle contraction."

The organoids grow to 6 millimeters in diameter on average and can be kept alive in the lab without deteriorating for several months. Currently, the oldest neuromuscular organoids have been kept in culture for 1 ½ years. Importantly, analysis showed neuromuscular organoids can be formed with similar efficiency from different human pluripotent stem cell lines. Thus, this will be a widely applicable approach, particularly suitable for the study of neuromuscular diseases using patient derived induced pluripotent stem cells (iPSCs).

A model for neuromuscular diseases

To assess the potential of NMOs to study neuromuscular diseases, the team modelled an autoimmune disease affecting neuromuscular junctions called myasthenia gravis. Serum from two patients with the disease was applied to several organoids for 72 hours and this resulted in fewer muscle contractions mirroring the muscle weakness experienced by patients.

"These findings recapitulate key aspects of disease pathology suggesting that the neuromuscular organoids can reliably model neuromuscular disorders," said Dr. Simone Spuler, a paper coauthor and researcher at the Charité Hospital Muscle Research Unit.

The diverse genetic origins and onset of debilitating neuromuscular diseases such as spinal muscular atrophy and amyotrophic lateral sclerosis have hampered the development of patient specific therapeutics. "The derivation of NMOs using patient-derived iPSCs will allow us to investigate their precise origin and progression. These organoids are better suited to study the contributions of specific cell types, such as terminal Schwann cells, at different stages of neuromuscular junction development and maturation that may contribute to neuromuscular diseases," Gouti clarified. Future studies will apply patient-derived neuromuscular organoids to assess the effectiveness of different drugs and for personalized medicine approaches.

Contrary to the findings of a 2019 study that associated the release of the Netflix series "13 Reasons Why" with an increase in monthly suicide rates among adolescent boys, a reanalysis of the data by the Annenberg Public Policy Center finds no evidence of contagion. The reanalysis, published today in PLOS ONE, found that after controlling for the dramatic increase in adolescent suicide in recent years, the show's release had no clear effect.

The reanalysis found that the increase in the suicide rate for boys observed in the original study by Bridge and colleagues for three months after the series' release was no longer evident after controlling for the ongoing trend in adolescent suicide. In addition, the increase seen during the first month of the release began the month prior to the release, making it difficult to attribute the rise to the show. The reanalysis found no effects in the subsequent months of that year.

"Our reanalysis casts considerable doubt on the show having an effect on boys," said author Dan Romer, Ph.D., research director of the Annenberg Public Policy Center (APPC) of the University of Pennsylvania. The paper, "Reanalysis of the Bridge et al. study of suicide following release of 13 Reasons Why," was published January 15, 2020, in PLOS ONE.

The original time-series analysis of suicide rates by Bridge et al. found an additional 195 suicide deaths among boys ages 10 to 17 during the nine months following the series' release, on March 31, 2017, but did not find a similar result among adolescent girls. Romer said he questioned that finding for two reasons: "First, contagion would be expected to be stronger for girls than boys because this show focuses on the suicide of a high school girl. Second, the prior analysis didn't take into account strong secular trends in suicide, especially in boys from 2016-2017."

APPC's reanalysis did find a modest rise in the suicide rate among adolescent girls during the first month following the release of "13 Reasons Why," but it was not statistically reliable.

Rising suicide rates for adolescents

Suicide rates for both adolescent males and females have been rising since 2008 and the rise in 2017 was particularly strong. The rate for young males ages 15 to 19 increased by 21 percent between 2016 and 2017. Suicide among female adolescents ages 15 to 19 increased by 7 percent.

There has been disagreement about the causes of the recent rise in adolescent and young adult suicide. Some researchers have suggested that the rise is due to increased use of social media. But a recently published analysis by Romer suggested that the trend may be attributable in part to lingering economic stress from the 2008 financial crisis in combination with increased pressure on teens from their parents to succeed academically.

'13 Reasons Why' and suicide contagion

When the first season of the Netflix show appeared in 2017, it created widespread concern that its graphic portrayal of a teenage girl's suicide would lead to imitation among vulnerable young people, especially adolescent girls. This concern prompted researchers to see whether there was evidence of contagion in U.S. suicide rates following the show's release.

The first such study, by Bridge et al., found evidence of a jump in suicides among boys ages 10 to 17 in the three months following the show's release, but no effect for girls. Romer said that analysis relied on a forecasting method to project the likely trend in suicide for 2017. But that forecast failed to anticipate the actual trend.

A second study by different researchers (Niederkrotenthaler et al.) in JAMA Psychiatry had a similar problem, Romer said. That study found an effect in boys and girls 10 to 19 years old in the three months following the series' release. But it similarly failed to control for the secular trend in suicide, again making it difficult to separate the effects of the show from the trend.

Potential for harm

APPC's analysis does not rule out the possibility that the show had an adverse effect, especially on girls. A previous study by Romer and colleagues that examined the effects of the second season of "13 Reasons Why" found that viewing the show had both beneficial and detrimental effects on young adult viewers. The small increase observed in girls in this current reanalysis of the first season data may have been the net result of these opposing effects, Romer said.

In mid-2019, over two years after the release, Netflix edited a graphic suicide scene from the Season 1 finale and asserted that the show encouraged young people "to start conversations about difficult issues such as depression and suicide and get help - often for the first time."

"Despite that, it does not appear that the show reversed or slowed the ongoing increase in adolescent suicide," Romer noted. "Even if the series also had a positive effect for some viewers, the producers should recognize the potential for harm to vulnerable audience members. It should be possible to produce a show that highlights the challenges that young people face without also producing suicide contagion."

Romer thanked Jeffrey Bridge for providing the data that were not available in his paper, which is in press in the Journal of the American Academy of Child & Adolescent Psychiatry.

Scientists from Australia's national science agency, CSIRO, and the University of California San Diego have engineered the first breed of genetically modified mosquitoes resistant to spreading all four types of the dengue virus.

Dengue infects more than 390 million people every year.

Typical symptoms include severe fever, headaches and muscle aches, with severe forms of the disease leading to haemorrhage, shock and even death.CSIRO Senior Research Scientist Dr Prasad Paradkar said the dengue virus was causing an epidemic in tropical and subtropical regions worldwide, with large outbreaks currently occurring in Bangladesh, Pakistan, Sri Lanka and the Philippines.

"There is a pressing global demand for effective strategies to control the mosquitoes that spread the dengue virus, as there are currently no known treatments and the vaccine that is available is only partially effective," Dr Paradkar said.

"In this study we used recent advances in genetic engineering technologies to successfully genetically modify a mosquito, the Aedes aegypti, with reduced ability to acquire and transmit the dengue virus.

"This is the first engineered approach that targets all four dengue types, which is crucial for effective disease suppression.

"Mosquito-transmitted viruses are expected to climb over the coming years, which is why CSIRO is focussed on developing new ways to help solve this global challenge."There have been previous attempts to synthetically engineer dengue-carrying mosquito populations to make them resistant to the virus, however these approaches had limited success due to their ability to only target one or two of the four major dengue types.

Incidences of dengue have increased dramatically in recent years, with more than half of the world's population now at risk of infection.

Global economic losses as a result of dengue are currently estimated to be $40 billion a year.

University of California San Diego Associate Professor and study co-author Omar Akbari said this development means that in the foreseeable future there may be viable genetic approaches to controlling dengue virus in the field, which could limit human suffering and mortality.

"This breakthrough work also has the potential to have broader impacts on controlling other mosquito-transmitted viruses," Associate Professor Akbari said.

"We are already in the early stages of testing methods to simultaneously neutralise mosquitoes against dengue and a suite of other viruses such as Zika, yellow fever and chikungunya."

The published research paper can be found in medical journal PLOS Pathogens, Thursday 16 January 2020.

The mosquitoes were tested in the quarantined insectary at the Australian Animal Health Laboratory in Geelong, CSIRO's national biocontainment facility designed to allow scientific research into dangerous infectious agents.

Photoelectrochemical (PEC) water splitting for hydrogen fuel generation has been considered the Holy Grail of electrochemistry. But to achieve it, many scientists believe the materials have to be abundant and low cost.

The most promising oxide photocathodes are cuprous oxide (Cu2O) photoelectrodes. In 2018 and 2019, researchers at EPFL achieved champion performance with cuprous oxide, rivaling photovoltaic (PV) semiconductor-based photocathodes.

But there was still a piece missing from the puzzle. Even state-of-the-art Cu2O photocathodes still use metallic back contacts (copper or gold), allowing for considerable electron-hole recombination. Other disadvantages include high cost and that the metal contact won't allow unabsorbed sunlight to pass through.

Now, scientists at EPFL show for the first time, that copper thiocyanate (CuSCN) can be used as a transparent and effective hole transport layer (HTL) for Cu2O photocathodes with overall enhanced performance. The research was led by Professors Anders Hagfeldt, Michael Grätzel, and Kevin Sivula at EPFL's Institute of Chemical Sciences and Engineering.

Detailed analysis on two types of CuSCN showed that a defective structure could be beneficial for hole conduction. Moreover, due to the coincidental alignment between valence bands of CuSCN and Cu2O, the band-tail states assisted hole transport in CuSCN was discovered to allow smooth hole conduction while efficiently block electron transport.

The optical advantages of CuSCN were further exhibited through a standalone PEC-PV tandem delivering a solar-to-hydrogen efficiency of 4.55%. This efficiency (4.55% for 12 h) is currently the highest among all Cu2O-based dual-absorber tandems.

The study presents a clear and impressive advancement beyond the state-of-the-art Cu2O photocathodes, which can contribute and inspire future development in the field.

"Though top numbers are achieved with the oxide material in this work, we believe higher values are not far," says Pan Lingfeng, the paper's first author. "At least three aspects are found to be not optimal, but improving them is very feasible. The efficiency value is getting closer and closer to the one that was previously thought to be the threshold for commercialization."

The chess world was amazed when the computer algorithm AlphaZero learned, after just four hours on its own, to beat the best chess programs built on human expertise. Now a research group at Aarhus University in Denmark has used the very same algorithm to control a quantum computer.

All across the world, numerous research groups are attempting to build a quantum computer. Such a computer would be able to solve certain problems that cannot be solved with current classical computers, even if we combined all these computers in the world into one.

At Aarhus University they share the ambition of building a quantum computer. For this reason, a research group under the direction of Professor Jacob Sherson has just used the computer algorithm AlphaZero to learn to control a quantum system.

What makes AlphaZero interesting is that it can learn on its own without any form of human expertise. In this manner, AlphaZero has beaten both humans and specialized computer programs in games such as Go, Shogi, and Chess, and it learned to do so only by playing against itself. After just four hours of playing against itself, AlphaZero managed to beat the leading chess program Stockfish. AlphaZero was so superior that Danish grand master Peter Heine Nielsen compared the program to a superior alien species that had visited the earth just to beat us in chess.

AlphaZero is good alone - but better with researchers

The research group at Aarhus University has, via computer simulations, demonstrated the broad applicability by applying AlphaZero on three different control problems that could each potentially be used in a quantum computer. Their work was recently published in Nature Quantum Information.

The team was very impressed with AlphaZero's ability to learn, as the lead PhD student Mogens Dalgaard described: "When we analyzed the data from AlphaZero we saw that the algorithm had learned to exploit an underlying symmetry of the problem that we did not originally consider. That was an amazing experience. ''

However, even though AlphaZero in itself is an impressive algorithm, the research team achieved the best results when they combined AlphaZero with a specialized quantum optimization algorithm. As Professor Jacob Sherson concludes: "This indicates that we are still in need of human skill and expertise, and that the goal of the future should be to understand and develop hybrid intelligence interfaces that optimally exploits the strengths of both".

In an attempt to speed up development in the field, the research group has made the code openly available and they were surprised about the interest. "Within a few hours I was contacted by major tech-companies with quantum laboratories and international leading universities to establish future collaboration" Jacob Sherson says and continues "so it will probably not be long until these methods will find use in practical experiments across the world."

Background info, the quantum computer:

A quantum computer uses quantum mechanics, a branch of physics that describes the smallest building blocks of our universe. At this small scale, the rules are fundamentally different. For instance, a system can exist in more than one state at a time. When translated into computer language, this means that a quantum computer can perform multiple calculations at a time, which gives a huge speed-up over regular computers. But even though the theory of quantum computers is well-established, no one has managed to build a full-scale quantum computer yet. This requires, among other things, that we improve our ability to control these systems.

UK scientists have identified a new way to kill pancreatic cancer cells by 'pulling the plug' on the energy generator that fuels calcium pumps on their cell surface. The study, published in the British Journal of Cancer, reports how switching off the cancer's energy supply causes the pancreatic cancer cells to become 'poisoned' by an irreversible build-up of calcium.

Calcium inside cells is normally beneficial as it controls numerous cell functions. However, calcium levels are tightly controlled and normally kept at very low levels, as prolonged elevations in calcium lead to cell death. This tight control is achieved by calcium pumps on the cell surface that use chemical energy to pump calcium out of the cell. The researchers discovered that switching off the cancer cells' energy supply causes these pumps to fail and calcium to rise, much like a damaged boat taking on water.

Dr Jason Bruce, from the Division of Cancer Sciences at the University of Manchester, who led the research, said: "Pancreatic cancer has some of the worst survival statistics and is notoriously resistant to standard treatments. Therefore, identifying potential weaknesses of pancreatic cancer cells that could be exploited to selectively kill them - essentially finding their 'Achilles Heel' - must remain a central research strategy if we are to tackle this devastating disease."

The research, funded by the UK charity Pancreatic Cancer Research Fund, identified that pancreatic cancer cells have a unique way of extracting energy from sugar to fuel their calcium pumps. They use a specific enzyme, called PKM2, which the researchers found in high levels in tumours compared to surrounding healthy tissue of patients with pancreatic cancer. They also found that the amount of PKM2 in tumours correlated with poor patient survival, suggesting this could be targeted to treat pancreatic cancer.

The Manchester team then carried out experiments on pancreatic cancer cells in the laboratory to find out what would happen if they shut down PKM2 using two different approaches. The first approach targeted the machinery responsible for making PKM2 protein, which eventually leads to a dramatic reduction or "knock-down" of PKM2 within the cancer cells. The second approach used a naturally occurring PKM2 blocker, called shikonin, which stops PKM2 from working. Shikonin was originally extracted from the dried roots of the Arnebia plant, which has been used in traditional Chinese medicine.

Shikonin was very effective at killing pancreatic cancer cells within just a few hours of treatment. Treated cells had depleted energy levels, which in turn led to the failure of their calcium pumps and a toxic rise in calcium. Shikonin also prevented the cells from growing and migrating, which implies an impact on cancer spread.

The team now intends to look for drugs that are more specific for PKM2 and other drugs that target similar energy-producing enzymes, and aim to investigate whether this approach could be developed into a new treatment for pancreatic cancer.

"Although shikonin proved to be very effective in the laboratory, it may have additional side effects around the body making it less useful in patients. Therefore, we aim to design new drugs that selectively target this process to selectively kill pancreatic cancer cells, while leaving healthy cells that rely on alternative energy sources relatively intact." explains Dr Bruce.

According to received wisdom, local activism against the establishment of industrial plants follows a cycle, with its highest intensity a short time after mobilization. If a firm stands, activism is destined to fade away. New research published in the Strategic Management Journal suggests us to think it again.

Fabrizio Perretti (Bocconi's Department of Management and Technology) and Alessandro Piazza (Jesse H. Jones School of Business) analyze the American anti-nuclear movement between 1960 and 1995 and find that the strategic decisions made by a firm affect both the evolution of activism in its own sector and the emergence of mobilization in other industries.

As expected, when activists are successful in preventing the establishment of a nuclear plant, there is an upsurge in similar protests in neighboring communities. Such a victory showcases activism as a viable opportunity for social change and activists remain mobilized to push further towards more ambitious goals. This dynamic is exemplified by the very first episode of protest against a nuclear power plant at Bodega Bay, California. In 1964 plans for the plant were canceled and, partly due to this success, a nationwide movement opposing nuclear power was soon born.

A protracted cycle of protest starting in 1976 could not, instead, prevent the construction of a nuclear power plant in Seabrook, New Hampshire, which was concluded in 1986. Despite their failure in achieving their goal, however, the Seabrook protests connected and inspired people around the country, establishing a dominant model of large-scale direct-action organization for groups championing different issues, including the AIDS activist group ACT UP.

&laquoFirms decisions can be considered critical events in a protracted conflict that not only determine local mobilization outcomes, but can also have boundary spanning effects», says Prof. Perretti. &laquoFurthermore, the idea that mobilization is more effective at its very onset proves wrong: all the conflicts about new plants go on for years, if not decades and activism effectiveness doesn't tend to wane over time».

Micromotors are artificial microscale devices which can achieve autonomous movement by converting supplied fuels or externally provided energy into kinetic energy. Since the concept of micromotors was proposed, great scientific interest has been attracted, as a consequence, impressive progress has been made in exploiting various kinds of micromotors. Major efforts have revealed that micromotors present copious values in fields of biomedical engineering, environmental science, and so on. In particular, there is considerable interest in the use of micromotors in biosensing. Compared with traditional methods, these micromotors based strategies are able to greatly enhance the sensitivity while largely reducing the assay time of biomolecules since the continuous movement of micromotors can increase the possibility of target-receptor contacts. Although with many progresses in this aspect, recently available micromotors employed in biosensors can only carry out with single target screening and cannot meet the requirement of multiplex and high-throughput analyses, which is usually necessary to guide diagnosis. Therefore, functional micromotors with the multiplexing capabilities are still anticipated in the biomedical areas.

In a new research article published in National Science Review, scientists at Southeast University present a novel kind of micrototors with stable structural color for multiplex assays. They formed particles of colloidal crystal clusters with stomatocyte morphology by rapid extracting solvent and assembling monodispersed nanoparticles in droplets. These stomatocyte particles could not only show striking structural colors and characteristic reflection peaks due to their ordered nanoparticles arrangement, but also provide effective cavities for the integration of functional elements. Thus, by using the platinum (Pt) and ferric oxide (Fe3O4) dispersed hydrogel to fill and duplicate the stomatocyte colloidal crystal particles, the barcode micromotors with catalyst or magnetic elements in their cavities, as well as with corresponding structural color coding, could be achieved. When these micromotors were exposed to a solution with hydrogen peroxide (H2O2) additive, the Pt-dispersed hydrogel in their cavities could propel the micromotors by expelling catalytic bubbles, while the present Fe3O4 could impart magnetic guidance for the micromotors. It was demonstrated that the self-movement of these structural color barcode micromotors could efficiently accelerate the mixing speed of the detection sample and greatly increase the probe-target interactions towards faster and more sensitive detection, and the magnetism of these barcode micromotors enable the flexible collection of the micromotors, which could facilitate the detection processes. Based on the specific identification feature of the stable structural color coding, the barcode micromotors could also perform an unprecedented simultaneous multiplexing capability for DNA detection. These results indicate that the structural color barcode micromotors will provide an ideal platform for ultrasensitive multiplex assays in different fields.