Tech

Universal fault-tolerant quantum computing relies on the implementation of quantum error correction. An essential milestone is the achievement of error-corrected logical qubits that genuinely benefit from error correction, outperforming simple physical qubits. Although tremendous efforts have been devoted to demonstrate quantum error correcting codes with different quantum hardware, previous realizations are limited to be against certain types of errors or to prepare special logical states. It remains one of the greatest and also notoriously difficult challenges to realize a universal quantum error correcting code for more than a decade.

In a new research article published in the Beijing-based National Science Review, scientists at the University of Science and Technology of China, the Tsinghua University, and at the University of Oxford, present their latest work on experimental exploration of five-qubit quantum error correcting code with superconducting qubits. The authors realized the [[5,1,3]] code on a superconducting quantum processor, verified the viability of experimental realization of quantum error correcting codes with superconducting qubits.

These scientists completed the important step towards the implementation of quantum error correction. This is achieved first by dedicated experimental optimization of superconducting quantum qubits, enabling the realization of more than a hundred quantum gates. Focusing on the five-qubit quantum error correcting code, the so-called 'perfect code' that corrects single generic qubit errors, they theoretically compiled and optimized its encoding process to have the minimal possible number (eight) of nearest-neighbor controlled-phase gates. These experimental and theoretical advances finally enabled the realization of the basic ingredients of a fully functional five-qubit error correcting code, involving the encoding of a general logical qubit into an error correcting code, with the subsequent verification of all key features including the identification of an arbitrary physical error, the power for transversal manipulation of the logical state, and state decoding.

"The device for the implementation of the five-qubit error correcting code is a 12-qubit superconducting quantum processor. Among these 12 qubits, we chose five adjacent qubits to perform the experiment. The qubits are capacitively coupled to their nearest neighbours. The capacitively coupled XY control lines enable the application of single-qubit rotation gates by applying microwave pulses, and the inductively coupled Z control lines enable the double-qubit controlled-phase gates by adiabatically tune the two-qubit state |11> close to the avoid level crossing of |11> and |02>. After careful calibrations and gate optimizations, we have the average gate fidelities as high as 0.9993 for single-qubit gates and 0.986 for two-qubit gates. With the implementation of only single-qubit rotation gates and double-qubit controlled-phase gates, we realized the circuit for encoding and decoding of the logical state." they state in an article titled "Experimental exploration of five-qubit quantum error correcting code with superconducting qubits."

"On a superconducting quantum processor, we experimentally realised the logical states |0>_L, |1>_L, |±>_L, and |±i>_L that are eigenstates of the logical Pauli operators X_L, Y_L, and Z_L, and the magic state |T>_L= (|0>_L+e^{i\pi/4}|1>_L)/\sqrt{2} that cannot be realized by applying Clifford operations on any eigenstate of the logical Pauli operators," they add. "Finally, the state fidelity of |T>_L reaches 54.5(4)%."

"The quality of the prepared logical states can also be divided into its overlap with the logical code space and its agreement with the target logical state after projecting it into the code space," they stated. After projecting to the code space, the average value is as high as 98.6(1)%. "Since projecting to the code space is equivalent to post-selecting all +1 stabilizer measurements, our result also indicates the possibility of high fidelity logical state preparation with future non-destructive stabilizer measurements."

After the realisation of logical state, the scientists proceed with the verification of error correction/detection ability of the five qubit code. "As shown in Fig.2(a) we do indeed find, for each case, the corresponding syndrome pattern that identifies the location of the single-qubit error," they added.

Then, the scientists implemented and verified the transversal logical operations, and performed the quantum process tomography within the code space to characterize these logical operations. "We determine gate fidelities of the logical X_L, Y_L, and Z_L operations to be 97.2(2)%, 97.8(2)%, and 97.3(2)%, respectively," they stated.

"Finally, after encoding the single-qubit input state into the logical state, we apply the decoding circuit, see Fig. 4(a), to map it back to the input state," they added. "After quantum process tomography from the four output states, the process fidelity is determined as 74.5(6)% as shown in Fig. 4(b)."

"An essential milestone on the road to fault-tolerant quantum computing is the achievement of error-corrected logical qubits that genuinely benefit from error correction, outperforming simple physical qubits," they add. "Direction for future works include the realization of non-destructive error detection and error correction, and the implementation of logical operations on multiple logical qubits for the five-qubit code. Our work also has applications in error mitigation for near-term quantum computing."

Non-orthogonal multiple access (NOMA) and millimeter-wave (mmWave) are two crucial techniques of 5G to meet the explosive capacity demands. On the other hand, UAVs deployed as aerial base stations are potential to provide ubiquitous coverage and satisfy users' multifarious requirements due to their flexibility and mobility. Nevertheless, the finite onboard energy is a fundamental limit of UAVs, which can deter the performance of UAV communication networks. Therefore, the researchers Xiaowei PANG and Nan ZHAO from Dalian University of Technology, Jie TANG and Xiuyin ZHANG from South China University of Technology, and Yi QIAN from University of Nebraska-Lincoln have focused on designing energy-efficient transmission schemes for mmWave-enabled NOMA-UAV networks. The network model is illustrated in Fig. 1, where the UAV equipped with multiple antennas serves K single-antenna ground users who are grouped into M clusters in the downlink.

"Although a large amount of research has contributed to integrating mmWave or NOMA with UAV communications, respectively," the five researchers wrote, "few of them investigated on mmWave-enabled NOMA-UAV networks."

In mmWave networks, the number of supported users conventionally cannot be larger than the number of RF chains at the same time-frequency resources. To break this fundamental limit, users are grouped into multiple clusters according to their channel correlations, and NOMA is employed in each cluster to serve the users simultaneously. To achieve a good balance between system complexity and performance, a hybrid precoding architecture is adopted to reduce the hardware cost and energy consumption. The authors aim to maximize the energy efficiency of mmWave-enabled NOMA-UAV networks by optimizing the UAV placement, hybrid precoding and power allocation. Due to the fact that the overall energy efficiency maximization problem is intractable, it is divided into several sub-problems. First, they optimize the UAV placement considering the total channel strength of all UAV-served users. And then, the hybrid precoding schemes with user clustering are proposed to better reap the multi-antenna gain. The last step is to optimize the power allocation among users to maximize the energy efficiency with users' quality of service requirements and an efficient algorithm is presented to solve the problem iteratively.

It's worth mentioning that three hybrid precoding schemes are introduced in the network, all of which perform user clustering and design the analog and digital precoding to improve the multiplexing gains and suppress the inter-user interference. Particularly, the major distinction among them is that they can achieve different performance of user fairness, spectrum efficiency and energy efficiency, which are further demonstrated by simulation results. The effectiveness of the proposed energy-efficient design is verified through numerical comparisons with other schemes without UAV placement optimization and without energy efficiency requirement. Moreover, numerical results also reveal the effects of the maximum UAV transmit power and the number of RF chains on the energy efficiency.

The habitats of freshwater fish species are threatened by global warming, mainly due to rising water temperatures. A 3.2-degree Celsius increase in global mean temperature would threaten more than half of the habitat for one third of all freshwater fish species. The number of species at risk is ten times smaller if warming is limited to 1.5 degrees. This is the conclusion of a study led by Radboud University, in collaboration with Utrecht University, PBL Netherlands Environmental Assessment Agency, Leiden University and others, and published in Nature Communications on March 15th.

Many studies have already assessed the potential impacts of climate change on animal and plant species in terrestrial systems. "However, freshwater fish species have been largely ignored, even though they represent approximately a quarter of the global known vertebrate diversity", says Valerio Barbarossa, lead author of the paper. This is the first study that investigated the potential impact of climate change on approximately 11,500 freshwater fish species around the globe.

Clear differences between global warming scenarios

With a global rise of 3.2 degrees Celsius, a scenario expected if there are no further emission cuts after current governments' pledges for 2030, over one third of the freshwater species have more than half of their present-day habitats threatened by extremes in water temperature or streamflow.

If global warming is limited to 2 degrees, 9% of the species would have more than a half of their habitat threatened. If warming is limited to 1.5 degrees, the number of species at risk reduces to 4%. "These numbers indicate that limiting global warming really matters for freshwater fish species, just as previous research has shown that it matters for species in terrestrial systems", says Barbarossa.

Temperature and flow

The researchers modelled future extremes in water flow and temperature and identified where these may exceed present-day extremes within the habitats of the fish species. "Water temperature and water flow are two key habitat factors for freshwater fish species. Climate change will amplify extremes in flow and temperature, which may reduce the amount of suitable habitat. This in turn is an important indicator of extinction risk", says Aafke Schipper, environmental researcher at Radboud University and PBL and co-author of the study.

The results of the study indicate that changes in water temperature are much more threatening than changes in flow extremes, reflecting that global warming will lead to rising water temperatures nearly everywhere. The findings further show that threats to freshwater fish species are particularly high in tropical waters.

Man-made barriers

"The numbers of species at risk represent a worst-case scenario in the sense that we assume that fish will not be able to move to other parts of the watershed or adapt to changed conditions", continues Barbarossa. "We have also considered a scenario in which species could move freely across the watershed and "escape" altered conditions. In that case, climate change threats would be substantially lower. However, many freshwater systems are fragmented, which impedes fish from moving to more suitable conditions."

River systems worldwide are characterized by an increasing number of many man-made barriers like dams, weirs, sluices or culverts. These reduce the connectivity of freshwater habitats and limit opportunities for fish to respond to climate change by shifting their ranges. This in turn stresses the need to limit global warming, the authors conclude, if we want to safeguard freshwater biodiversity.

Robotics researchers are developing exoskeletons and prosthetic legs capable of thinking and making control decisions on their own using sophisticated artificial intelligence (AI) technology.

The system combines computer vision and deep-learning AI to mimic how able-bodied people walk by seeing their surroundings and adjusting their movements.

"We're giving robotic exoskeletons vision so they can control themselves," said Brokoslaw Laschowski, a PhD candidate in systems design engineering who leads a University of Waterloo research project called ExoNet.

Exoskeletons legs operated by motors already exist, but users must manually control them via smartphone applications or joysticks.

"That can be inconvenient and cognitively demanding," said Laschowski, also a student member of the Waterloo Artificial Intelligence Institute (Waterloo.ai). "Every time you want to perform a new locomotor activity, you have to stop, take out your smartphone and select the desired mode."

To address that limitation, the researchers fitted exoskeleton users with wearable cameras and are now optimizing AI computer software to process the video feed to accurately recognize stairs, doors and other features of the surrounding environment.

The next phase of the ExoNet research project will involve sending instructions to motors so that robotic exoskeletons can climb stairs, avoid obstacles or take other appropriate actions based on analysis of the user's current movement and the upcoming terrain.

"Our control approach wouldn't necessarily require human thought," said Laschowski, who is supervised by engineering professor John McPhee, the Canada Research Chair in Biomechatronic System Dynamics. "Similar to autonomous cars that drive themselves, we're designing autonomous exoskeletons and prosthetic legs that walk for themselves."

The researchers are also working to improve the energy efficiency of motors for robotic exoskeletons and prostheses by using human motion to self-charge the batteries.

Dr Daniel Montesinos is a Senior Research Fellow at the Australian Tropical Herbarium, at James Cook University in Cairns. He is studying weeds to better understand (among other things) how they might respond to climate change.

He said most invasive plants are characterised by their rapid pace when it comes to taking up nutrients, growing, and reproducing - and they're even faster in the regions they invade.

"New experiments comparing populations from distant regions show a clear trend for already-fast invasive plants to rapidly adapt even faster traits in their non-native regions," Dr Montesinos said.

This is further pronounced in the tropics and sub-tropics.

"Even though invasives' growth rates are already among the highest for plants, when they invade new territory in the tropics and sub-tropics, they develop those weedy traits more rapidly than they do when they invade in temperate climates," Dr Montesinos said.

"This might be explained by higher chemical processing at higher temperatures, which suggests that global warming will increase invasive impacts in these regions, as long as enough water is available."

Dr Montesinos said invasive plants usually take hold in land that has been disturbed by human intervention (for example farms and roadsides) and then spread to other habitats.

"It's important to recognise disturbed habitats as a gateway for plant invasions," Dr Montesinos said. "If we can limit disturbance of natural environments, we can reduce biological invasions, particularly in tropical areas that are threatened by increasing human encroachment."

Dr Montesinos said that range expansions by native species trying to 'escape' from changes in climate could be a further complication. This involves climate change enabling some native plants to grow where they previously could not.

"This can be seen as a double-edged sword - some native species will survive climate change, but they might achieve that by disrupting the habitats of others.

"The study of invasion ecology is complex, but invasive species can be models in which to study, and make predictions about, the responses of native plants to climate change, giving us clues on improved management techniques for both natives and invasives," Dr Montesinos said.

Last December, the Parliament of Catalonia unanimously approved the incorporation into its legislation of second-order violence against those who give their support to victims of violence against women. A recent study compiles testimonies of victims, and analyses this form of intimidation

To tackle violence against women, it is essential for victims to have the support of those surrounding them and to prevent them from being isolated. But what happens if the people around them are not protected? The work of Jose Ramón Flecha García, founder of the Community of Research on Excellence for All (CREA), and various academic teams, has led to the approval in the Catalan parliament of the first legislation on the Second Order of Sexual Harassment (SOSH).

The following point has been included in Law 17/2020 of 22 December: Second-Order Violence. It consists of physical or psychological violence, reprisals, humiliation, and persecution against persons who support victims of violence against women. It includes acts that impede the prevention, detection, care, and recovery of women in situations of violence against women.

"There was unanimity in parliament. The legal protection that this law offers to supporters is already having a social and political impact in Catalonia. A growing number of institutions and organisations are reflecting on how to include this protection in their protocols. Attacks on those who support victims, which until now were against ethics, are now also against the law," says Flecha García, who has analysed this form of violence in an article published in the journal Violence Against Women, to SINC.

For the scientist, victims can only become survivors if they find support "and this support is only given, with honourable and heroic exceptions, with legislation and institutional actions taken against the cruel reprisals suffered by those who support them. Without such legislation, the law that rules is the code of silence, which is the main ally of the harassers, as it guarantees the isolation of the victims," he adds.

"In Catalonia, both the associative movement and researchers committed to overcoming gender-based violence have been working together for some time. In the framework of the first research on gender-based violence in Spanish universities, some cases of second-order violence were already identified," as Patricia Melgar Alacantud, professor and researcher at the University of Girona and member of the CREA Women's Group, has told SINC.

This work, published in 2016 and co-led by Melgar Alacantud, gathered very significant data in this area, such as the fact that 91% of cases of aggression in Spanish universities are not reported.

"I have no doubt that soon other autonomous communities, as well as other countries, will also include this type of violence in their laws. Ramón Flecha's article will play an important role. His courageous work rigorously analyses this reality that we all know and leaves those who frequently perpetuate silence regarding gender-based violence, isolate the victims or sow terror through their reprisals in a difficult position. I say courageous because researching gender violence, daring to make its existence visible in certain contexts, has a personal and professional cost", the researcher reports.

The legal consequences of this step forward in Catalonia will mean that the protection of victims, as well as all the resources to which direct victims of gender-based violence are entitled, will now also be available to victims of second-order violence. This refers, for example, to accompaniment, psychological or legal assistance.

The testimony of those who have suffered it
In her study, Flecha García relies on the stories of six people - four women and two men - who have suffered second-degree sexual harassment in Spain. "Their stories allow us to define the characteristics of this type of violence and provide key elements for learning how to combat it," she explains.

A secondary school teacher, a primary school teacher, a researcher, a man whose sister was abused by a family friend, a woman who is an active member of a political party and an employee of a non-profit organisation became victims of SOSH because they showed their support for the victims.

All of them suffered psychological violence, personal reprisals and in some cases reprisals on the job. In addition, in one case there was physical violence. Marina (not her real name) tells of how the man who sexually abused the girl tried to physically assault her after one of the cases of sexual abuse she reported.

The research shows that stalkers commit second-order sexual harassment through humiliation, threats and lies aimed at tarnishing the personal and professional reputation of victims and undermining their credibility.

Fear of reprisals

In Flecha García's research, the six people who shared their testimonies gave their consent to participate, subject to preserving their anonymity and not providing any information that could identify them. In all cases, the experience of second-order sexual harassment lasted for at least one year. Data collection focused on analysing the characteristics of this type of violence, identifying the particularities of each context and the social interactions surrounding these experiences. "Unfortunately, fear was also present in these interviews," Flecha continues.

"Reprisals are so cruel that if we leave it to individual heroism alone, the majority will continue to look the other way in specific cases and there will continue to be very few individual persons who support the victims," Flecha García stresses.

Flecha recounts cases of families where the father abuses his daughter, but she does not receive the expected support because "mere internal denunciation within the family provokes a great deal of rejection." He also points out that in the university itself, members of the equality commissions, after having supported the victims, "have been expelled from these commissions and are so afraid that they do not want this to be talked about"; and recalls one of the most famous cases in Spain, that of a professor at the University of Barcelona who was investigated for sexual harassment complaints from 14 people, which was sent to the public prosecutor's office when the statute of limitations had already expired.

Violence in plain sight

For Melgar Alacantud, the fact that these realities began to be made visible in the media and social networks "began to create a breeding ground, but at the same time it constituted an uncomfortable reality in the face of which you either become an accomplice or join in the efforts to transform," she stresses. This second option brought together some researchers, lawyers, social movements, and policy-makers who placed importance on basing changes to the law on evidence.

In other areas, such as in some schools in Spain and other countries, clubs of 'valientes violencia 0' ('0 violence brave persons') have arisen. These groups act as a shield for potential victims so that they do not become victims. "These successful actions must be extended to the whole of society by passing appropriate legislation," argues Flecha.

The University of Girona researcher also points out that it is important to differentiate between the results of research such as Flecha's and what will later be implemented by law. "I have high hopes for this advance, but I also had them for the protocols against harassment when they began to be extended and, in some cases, left much to be desired," she says.

It is still too early to know how the implementation of the law will define the protection of these people, but what experts are aware of is that protecting them will promote support for those who suffer directly from gender-based violence.

During pandemics, protective behaviors need to be motivated by effective communication. A critical factor in understanding a population's response to such a threat is the fear it elicits, since fear both contributes to motivating protective responses, but can also lead to panic-driven behaviors. Furthermore, lockdown measures affect well-being, making it important to identify protective factors that help to maintain high perceived levels of health during restrictions. An international team of researchers led by scientists from the University of Vienna has now identified psychological predictors of fear and health during the lockdowns. The result of the study, published in PLOS ONE: Individual psychological variables have a much better predictive power than environmental variables.

The current publication aims to identify predictors of fear and perceived health during stay-at-home orders in response to the COVID-19 pandemic. "This way we can predict how different people and populations will react to external threats and restrictions," explains Stephanie Eder from the Faculty of Psychology.

Researchers from the University of Vienna in collaboration with scientists from the University of Wroclaw (PL), University of Barcelona (ESP), Charles University and Jan Evangelista Purkyne University (CZ) have investigated 533 participants during the 'first wave' of the COVID-19 pandemic in Europe.

Utilizing machine-learning models, they identified psychological predictors of fear and health during the lockdowns. Fear can be predicted very well when worries about shortages in supply, perceived infectability to diseases in general, germ aversion, and infections in the immediate social sphere are taken into account. Predictors of perceived health include higher perceived infectability to diseases in general, attachment security, physical activity and younger age; suggesting that older populations with high perceived infectability and insecure attachment may be most vulnerable during these uncertain times.

Interestingly, environmental variables such as the local severity of lockdown restrictions and mortality had no predictive value for either of the target variables.
"We could show the value of 'micro-level', psychological factors over macro-scale environmental conditions when predicting a population's response to a crisis and when designing behavioral interventions for specific target groups.", says Eder.

We all have a clear picture in mind when we think of metals: We think of solid, unbreakable objects that conduct electricity and exhibit a typical metallic sheen. The behaviour of classical metals, for example their electrical conductivity, can be explained with well-known, well-tested physical theories.

But there are also more exotic metallic compounds that pose riddles: Some alloys are hard and brittle, special metal oxides can be transparent. There are even materials right at the border between metal and insulator: tiny changes in chemical composition turn the metal into an insulator - or vice versa. In such materials, metallic states with extremely poor electrical conductivity occur; these are referred to as "bad metals". Until now, it seemed that these "bad metals" simply could not be explained with conventional theories. New measurements now show that these metals are not that "bad" after all. Upon closer inspection, their behaviour fits in perfectly with what we already knew about metals.

Small change, big difference

Prof. Andrej Pustogow and his research group at the Institute for Solid State Physics at TU Wien (Vienna) are conducting research on special metallic materials - small crystals that have been specially grown in the laboratory. "These crystals can take on the properties of a metal, but if you vary the composition just a little bit, we are suddenly dealing with an insulator that no longer conducts electricity and is transparent like glass at certain frequencies," says Pustogow.

Right at this transition, one encounters an unusual phenomenon: the electrical resistance of the metal becomes extremely large - larger, in fact, than should be possible at all according to conventional theories. "Electrical resistance has to do with the electrons being scattered at each other or at the atoms of the material", explains Andrej Pustogow. According to this view, the greatest possible electrical resistance should occur if the electron is scattered at every single atom on its way through the material - after all, there is nothing between an atom and its neighbour that could throw the electron off its path. But this rule does not seem to apply to so-called "bad metals": They show a much higher resistance than this model would allow.

It all depends on the frequency

The key to solving this puzzle is that the material properties are frequency-dependent. "If you just measure the electrical resistance by applying a DC voltage, you only get a single number - the resistance at zero frequency," says Andrej Pustogow. "We, on the other hand, made optical measurements using light waves with different frequencies."

This showed that the "bad metals" are not so "bad" after all: At low frequencies they hardly conduct any current, but at higher frequencies they behave as one would expect from metals. The research team considers tiny amounts of impurities or defects in the material, that can no longer be adequately shielded by a metal at the boundary to an insulator, as a possible cause. These defects can cause some areas of the crystal to no longer conduct electricity because there the electrons remain localized in a certain place instead of moving through the material. If a DC voltage is applied to the material so that the electrons can move from one side of the crystal to the other, then virtually every electron will eventually hit such an insulating region and current can hardly flow.

At high AC frequency, on the other hand, every electron moves back and forth continuously - it does not cover a long distance in the crystal because it keeps changing direction. This means that in this case many electrons do not even come into contact with one of the insulating regions in the crystal.

Hope for important further steps

"Our results show that optical spectroscopy is a very important tool for answering fundamental questions in solid-state physics," says Andrej Pustogow. "Many observations for which it was previously believed that exotic, novel models had to be developed could very well be explained by existing theories if they were adequately extended. Our measurement method shows where the additions are necessary." Already in earlier studies, Prof. Pustogow and his international colleagues gained important insight into the boundary region between metal and insulator using spectroscopic methods, thus establishing a fundament for theory.

The metallic behaviour of materials subject to strong correlations between the electrons is also particularly relevant for so-called "unconventional superconductivity" - a phenomenon that was discovered half a century ago but is still not fully understood.

(Portland - March 15) Results of a clinical study conducted by researchers in Manaus, Brazil, show that the Gazelle® Malaria test outperformed Rapid Diagnostic Tests (RDTs) and was nearly as accurate as more expensive and time-consuming expert microscopy in detecting Plasmodium vivax (P. vivax) malaria. The data was published Friday, March 12 in the Malaria Journal.

The double-blind study was based on 300 participants who sought care from Fundac?a?o de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD), located in Manaus, an area in the Western Brazilian Amazon, heavily endemic for P. vivax.

"Because P. vivax is not adequately detected by current tests, the infection is frequently missed, and patients don't receive essential treatment," said Dr. Marcus Lacerda, Infectious Disease Researcher at FMT-HVD and lead investigator for the study.

"This causes recurrent symptoms and contributes to the spread of the disease. These results shows that we're on a path to reduced suffering and faster malaria elimination."

P. vivax is the second most prevalent malaria species infecting humans and is widespread among many countries seeking to eliminate malaria. Although considered less deadly than P. falciparum (the most common species), P. vivax infections can result in serious illness and mortality.

Additionally, P. vivax presents a special challenge for diagnostics due to its typically low levels of parasitemia. Current RDTs miss many P. vivax infections, thus light microscopy, which is time-consuming and requires skilled technicians, is the current best option for many regions of the world.

Researchers at FMT-HVD noted that the Gazelle Malaria Test's use of hemozoin, a highly specific biomarker present in all species of malaria, shows promise for detecting low parasitemia P. vivax infections.

When compared to optical microscopy in this study, the sensitivity and specificity of the Gazelle test were 96.2% and 100% respectively, whereas for RDTs they were 83.9% and 100%. This equates to RDTs missing 16 cases of P. vivax infection per 100 people, and Gazelle missing only 4.

The researchers also noted that Gazelle's portability, all-day battery operation, and supplies that do not require cold chain, make the device a promising alternative to light microscopy in field conditions.

"This milestone aligns with Hemex's strategy to assist countries with elimination efforts," said Patti White, CEO of Hemex Health. "We fully expect that with Gazelle's affordability, ease-of-use, and ultra-fast results, it can be used successfully for case management, mass and border screenings or during outbreaks."

The company has regulatory approval in a growing number of countries, including India, Kenya, and Ghana, and plans to apply for approval in South America soon.

Copper nanomaterials with a cubic shape so perfect that they form neatly aligned stacks when brought together have been created by researchers at KAUST. The cuboid copper nanoclusters, developed by rational design, are a new member of an exotic nanomaterial family that has shown many promising properties but has remained very hard to make.

"Copper nanomaterials are a class of materials that exhibit useful properties for the fields of photoluminescence and catalysis," says Ren-Wu Huang, a postdoc in Osman Bakr's lab, who led the research. There is great interest in synthesizing new copper nanomaterials to understand how their structure influences their function.

Copper nanoclusters, which are of an atomically precise structure, are among the few copper nanomaterials that can provide such insights at the atomic level because their total structure can be determined by single-crystal x-ray diffraction. "However, the synthesis of copper nanoclusters is still a great challenge and its pace of development is slow compared to nanoclusters made from its sister metals, silver and gold," Huang adds.

In their latest work, the team aimed to make a hydrogen-rich polyhydrido copper nanocluster (PCN). "To create the cuboid-shaped nanoclusters, we added triphenylphosphine (Ph3P) to our synthesis reaction system," says Bakr. Based on previously synthesized PCN structures, the team predicted that triphenylphosphine, with its rigid conical structure, would help to create a new nanocluster with a cuboid shape.

The dark-orange block-like crystals that the team isolated from the reaction mixture did prove to be a novel PCN structure with the predicted cuboid shape. Single-crystal x-ray diffraction showed that the heart of each nanocluster contained 23 copper atoms. Surrounding this core were eight triphenylphosphine groups, forming the eight corners of the cube.

Strikingly, each dark-orange crystal consisted of multiple cuboid nanoclusters, stacked neatly together in perfectly aligned rows and columns. "We found that the subtle synergy between the cuboid shape and the intercluster noncovalent bonding interactions, such as hydrogen bonding and van der Waals interactions, is the main driving force for the unique simple cubic self-assembly of nanoclusters," Huang says.

Despite the team's latest discoveries, copper nanocluster research is still in its infancy. "Crucial questions about the growth mechanism, structure evolution and structure-property relationships of clusters are yet to be addressed," Bakr says. "We aim to shed light on those issues and to move forward with exploiting the potential of the clusters for important catalytic reactions."

In the world of neurodevelopment, one thing is clear: the earlier the intervention the better. Infancy is a critical time in brain development, and neuroscientists are increasingly identifying factors that can negatively impact cognition and ones that can improve cognition early in life. At the annual meeting of the Cognitive Neuroscience Society (CNS), researchers from the University of Minnesota are presenting new work on two early interventions: one on the potential use of engineered gut microbes for antibiotic-exposed infants and another on a choline supplement to treat infants exposed prenatally to alcohol.

"These talks underscore how patient-based neuroscience can advance the field of neonatal and infant care, providing evidence-based interventions for improving cognition," says Nathalie Maitre of Nationwide Children's Hospital, who is chairing the CNS symposium on the neonatal and infant brain. "They also show the interdisciplinary nature of this field, bringing together medical doctors with cutting-edge neuroimaging, as well as other specialized fields like microbiology."

A microbial approach to infant health

"As a pediatrician specializing in the care of ill newborn infants, I am always concerned with how early-life exposures affect relevant long-term health outcomes," says Dr. Cheryl Gale of the University of Minnesota. Her team has thus set out to combine microbial genomic analyses, biological computational approaches, and functional brain assessment to better understand neurodevelopment in very young infants.

At CNS, Gale will present new research that shows that infants with different compositions of gut bacteria process auditory and visual stimuli differently during memory tasks. "These results raise the possibility that gut bacteria are involved in the development of brain function," she says.

The study, published online in Pediatric Research and led by Marie Hickey, compares the brain activity of infants who were given antibiotics to those who were not within their first month of life. The researchers used EEG to record a type of electrical activity called event related potentials (ERPs) in the brains of the infants in response to their mother's voice or a stranger's voice - a type of memory called "recognition memory" that can be assessed in preverbal infants before any behavioral changes are apparent.

"Recognition memory is one of the earliest types of explicit memory to develop and is known to be dependent on medial temporal lobe structures, including the hippocampus, the brain region affected by microbiome perturbation in animal models," Gale explains. Indeed, previous research on the gut-brain connection has been almost exclusively in animal models, making this human study especially valuable and unique. At the same time, the ERP technique has been used extensively in other research to successfully predict a range of behaviors, such as later language development, reading ability, and risk for autism.

The antibiotic-exposed infants' ERP measurements indicated an abnormal response to their mother's voices compared to the non-antibiotic-exposed infants. All infants were otherwise healthy, and the researchers worked to control for other variables, such as inflammatory responses and gestational age of the infant.

While the new study showed a relationship between early antibiotic exposure and brain function in participants, the researchers have yet to determine a causal relationship. "We don't yet know if there is a definitive cause and effect relationship between microbes and brain function in human infants, but future research will hopefully be able to shed light on this," Gale says.

The work does raise the possibility of creating engineered microbes as an intervention to help people early in life. "Infancy is a critical time window for brain development, when therapeutic interventions can have effects for the life-course," Gale says.

A supplement to reverse damage

Despite decades of research showing the detrimental effects of consuming alcohol during pregnancy, fetal alcohol syndrome is still common around the world - affecting approximately 8 of 1000 people in the general population, according to a 2017 study in JAMA Pediatrics. The syndrome leaves infants with structural brain abnormalities and cognitive impairments, among other deleterious effects.

Jeff Wozniak remembers encountering his first clinical cases of fetal alcohol spectrum disorders early in his career and realizing for the first time "that this was a very unique, poorly understood population with very high needs." He also realized that there was an absence of imaging studies in this population. "So I became interested in using some of the tools that we had available here at the University of Minnesota to do high-quality imaging of brain structure and function in this understudied population to learn something about how the brain is altered by prenatal alcohol exposure at the earliest stages of development."

From this work, he and his colleagues have identified a number of ways in which prenatal alcohol exposure causes the loss of brain cells and the interruption of important developmental processes, including gene expression. For example, he says, alcohol may interfere with genes involved in the myelination process throughout the brain.

This research has included work on a potential treatment, specifically an early intervention through supplementing with the nutrient choline. Over a decade-long randomized, double-blind, and placebo-controlled study, they have seen how postnatal choline supplementation in 2- to 5-year-olds with prenatal alcohol exposure has translated to cognitive benefits compared to those without the supplementation.

At CNS, he will present findings from participants, four years after their choline supplementation and with no further interventions since. Those who received choline early in life showed higher non-verbal intelligence, higher visual-spatial skill, higher working memory ability, better verbal memory, and fewer behavioral symptoms of attention deficit hyperactivity disorder (ADHD) than those in the placebo group.

"The further back you go and do your intervention, the more leverage you have to alter the developmental trajectory of that particular child," Wozniak says. "So that was the exciting thing about bringing those children back and looking at their development and seeing much larger choline versus placebo effects in cognitive functions like working memory and even behavioral differences in terms of ADHD."

The link between nutrients and brain development is not new; for example, folic acid has long been established as a supplement that prevents neural tube disorders. However, longitudinal studies that test the nutritional intervention's impacts on cognition over time are relatively new, marking an exciting convergence of cognitive neuroscience and pediatric health.

Wozniak sees this work as the start of a potential paradigm shift in addressing a range of neurodevelopmental trajectories and disorders. "Our interventions are baby steps but really important baby steps because they're showing us and others that we shouldn't think of these conditions as static injuries that took place prenatally and that that is the end of the story," he says. "Rather, we should learn about what developmental processes have gone awry and then go back as early as we can in treating these children, identifying them and treating them in a way that optimizes the rest of neurodevelopment."

Men experiencing vital exhaustion are more likely to have a heart attack, according to research presented today at ESC Acute CardioVascular Care 2021, an online scientific congress of the European Society of Cardiology (ESC).1 The risk of a myocardial infarction linked with exhaustion was particularly pronounced in never married, divorced and widowed men.

"Vital exhaustion refers to excessive fatigue, feelings of demoralisation and increased irritability," said study author Dr. Dmitriy Panov of the Institute of Cytology and Genetics, Novosibirsk, Russian Federation. "It is thought to be a response to intractable problems in people's lives, particularly when they are unable to adapt to prolonged exposure to psychological stressors."

This study examined the relationship between vital exhaustion and the risk of myocardial infarction in men with no history of cardiovascular disease. The study used data from the World Health Organization (WHO) MONICA Project.2 A representative sample of 657 men aged 25 to 64 years in Novosibirsk was enrolled in 1994.

Symptoms of vital exhaustion were assessed at baseline using the Maastricht Vital Exhaustion Questionnaire adopted by the MONICA protocol. Participants were classified according to their level of vital exhaustion: none, moderate, or high. Participants were followed-up for 14 years for the incidence of heart attack.

Overall, two-thirds (67%) of the men had vital exhaustion (15% had a high level and 52% had a moderate level) while 33% were unaffected. Nearly three-quarters (74%) of men with high blood pressure had vital exhaustion - high in 58% and moderate in 16%.

In the overall group of men, the researchers analysed the association between vital exhaustion at baseline and the risk of having a heart attack. Compared to those without vital exhaustion, men with moderate or high levels had a 2.7-fold greater risk of a heart attack within five years, a 2.25 higher risk within 10 years, and a 2.1 raised risk within 14 years (p for all

When the analysis was controlled for social factors (education, occupation, and marital status) and age, the influence of vital exhaustion on heart attack risk decreased but remained statistically significant. For example, compared to those without vital exhaustion, men with moderate or high levels were 16% more likely to have a myocardial infarction over 14 years of follow-up compared to those without after adjusting for social factors and age (p

In the adjusted analysis, the risk of a heart attack linked with exhaustion was higher in never married, divorced, and widowed men compared to married men - with hazard ratios of 3.7, 4.7, 7.0, respectively. The risk of a heart attack related to exhaustion was 2.2-fold higher in those with an elementary school education compared to men with a university degree. Middle-aged men were more affected than younger men: compared to 24-34-year-olds, the risk of a heart attack connected with exhaustion was 3.8-fold higher in 45-54-year-olds and 5.9-fold higher in 55-64-year-olds.

Regarding the influence of marital status on the relationship between exhaustion and heart attack, Dr. Panov said: "Living alone indicates less social support, which we know from our prior studies is an independent risk factor for myocardial infarction and stroke."

He noted that the findings indicate a pattern whereby social disadvantage relates to vital exhaustion, which is associated with a greater risk of heart disease. "The relationship of exhaustion with threatening cardiovascular events should be taken into account when assessing risk," he said.

Dr. Panov concluded: "Efforts to improve well-being and reduce stress at home and at work can help reduce vital exhaustion. Involvement in community groups is one way to increase social support and become less vulnerable to stress. Together with a healthy lifestyle, these measures should be beneficial for heart health."

A machine learning algorithm that predicts suicide attempt recently underwent a prospective trial at the institution where it was developed, Vanderbilt University Medical Center.

Over the 11 consecutive months concluding in April 2020, predictions ran silently in the background as adult patients were seen at VUMC. The algorithm, dubbed the Vanderbilt Suicide Attempt and Ideation Likelihood (VSAIL) model, uses routine information from electronic health records (EHRs) to calculate 30-day risk of return visits for suicide attempt, and, by extension, suicidal ideation.

Suicide has been on the rise in the U.S. for a generation and is estimated to claim the lives of 14 in 100,000 Americans each year, making it the nation's tenth leading cause of death. Nationally, some 8.5% of suicide attempts end in death.

Colin Walsh, MD, MA, and colleagues evaluated the performance of the predictive algorithm with an eye to its potential clinical implementation. They reported the study in JAMA Network Open.

Upon stratifying adult patients into eight groups according to their risk scores per the algorithm, the top stratum alone accounted for more than one-third of all suicide attempts documented in the study, and approximately half of all cases of suicidal ideation. As documented in the EHR, one in 23 individuals in this high-risk group went on to report suicidal thoughts, and one in 271 went on to attempt suicide.

"Today across the Medical Center, we cannot screen every patient for suicide risk in every encounter -- nor should we," said Walsh, assistant professor of Biomedical Informatics, Medicine and Psychiatry. "But we know some individuals are never screened despite factors that might put them at higher risk. This risk model is a first pass at that screening and might suggest which patients to screen further in settings where suicidality is not often discussed."

Over the 11-month test, some 78,000 adult patients were seen in the hospital, emergency room and surgical clinics at VUMC. As subsequently documented in the EHR, 395 individuals in this group reported having suicidal thoughts and 85 lived through at least one suicide attempt, with 23 surviving repeated attempts.

"Here, for every 271 people identified in the highest predicted risk group, one returned for treatment for a suicide attempt," Walsh said. "This number is on a par with numbers needed to screen for problems like abnormal cholesterol and certain cancers. We might feasibly ask hundreds or even thousands of individuals about suicidal thinking, but we cannot ask the millions who visit our Medical Center every year -- and not all patients need to be asked. Our results suggest artificial intelligence might help as one step in directing limited clinical resources to where they are most needed."

Walsh, who originally created the algorithm with colleagues now at Florida State University, had previously validated it using retrospective EHR data from VUMC.

"Dr. Walsh and his team have shown how to stress test and adapt an artificial intelligence predictive model in an operational electronic health record, paving the way to real world testing of decision support interventions," said the new study's senior author, William Stead, MD, professor of Biomedical Informatics.

What The Study Did: Researchers investigated whether acute COVID-19 symptoms are associated with the probability of subsequent depressive symptoms.

Authors: Roy H. Perlis, M.D., M.Sc., of the Massachusetts General Hospital in Boston, is the corresponding author.

To access the embargoed study:  Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2021.3223)

Editor's Note: Editor's Note: The article includes conflict of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

What The Study Did: National claims data were used to look at changes in well-child care visits with out-of-pocket costs before and after passage of the Affordable Care Act.

Authors: Paul R. Shafer, Ph.D., of Boston University, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2021.1248)

Editor's Note: Editor's Note: The article includes conflicts of interest disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.