Tech

Researchers at the University of Health Sciences, Medical Informatics and Technology (UMIT, Hall, Austria) and the University of the Balearic Islands (Palma de Mallorca, Spain) have confirmed the analgesic effects of social support - even without verbal or physical contact.

The short communication, entitled "Dispositional empathy is associated with experimental pain reduction during provision of social support by romantic partners" by Stefan Duschek, Lena Nassauer, Casandra I. Montoro, Angela Bair and Pedro Montoya has recently been published in the Scandinavian Journal of Pain.

The authors assessed sensitivity to pressure pain in 48 heterosexual couples with each participant tested alone and in the passive presence of their partner. Dispositional empathy was quantified by a questionnaire.

In the presence, as compared to the absence, of their partners both men and women exhibited higher pain thresholds and tolerance as well as lower sensory and affective pain ratings on constant pressure stimuli. Partner empathy was positively associated with pain tolerance and inversely associated with sensory pain experience.

"Repeatedly, talking and touching have been shown to reduce pain, but our research shows that even the passive presence of a romantic partner can reduce it and that partner empathy may buffer affective distress during pain exposure," said Professor Stefan Duschek of UMIT, speaking on behalf of the authors.

Certain semiconductor structures, so-called quantum dots, might constitute the foundation of quantum communication. They are an efficient interface between matter and light, with photons (light particles) emitted by the quantum dots transporting information across large distances. However, structures form by default during the manufacture of quantum dots that interfere with communication. Researchers at the University of Basel, Ruhr-Universität Bochum, and Forschungszentrum Jülich have now successfully eliminated these interferences. They've published their report in the journal Communications Physics from 9 August 2019.

Light particles capable of transporting information across large distances

Quantum dots can be realised in semiconductors if researchers lock an electron and an electron hole - i.e. a positive charge at a position where an electron should exist - in a constricted space. Together, electron and electron hole form an excited state. When they recombine, the excited state disappears and a photon is generated. "That photon might be usable as information carrier in quantum communication across large distances," says Dr. Arne Ludwig from the Chair for Applied Solid State Physics in Bochum.

The quantum dots manufactured in Bochum are generated in the semiconductor material indium arsenide. The researchers grow the material on a gallium arsenide substrate. In the process, a smooth indium arsenide layer forms at a thickness of a mere one and a half atomic layers - the so-called wetting layer. Subsequently, the researchers generate small islands with a diameter of 30 nanometres and a height of a few nanometres. These are the quantum dots.

Interfering photons from wetting layer

The wetting layer that has to be deposited in the first step causes problems, because it, too, contains excited electron hole states that decay and may release photons. In the wetting layer, these states decay even more easily than in the quantum dots. The photons emitted in the process can't be used in quantum communication, however; rather, they generate a static noise in the system.

"The wetting layer covers the entire surface while the quantum dots only cover a thousandth of the semiconductor chip, which is why the interfering light is approximately a thousand times stronger than the light emitted by the quantum dots," explains Andreas Wieck, Head of the Chair for Applied Solid State Physics in Bochum. "The wetting layer radiates photons at a slightly higher frequency and at a much higher intensity than the quantum dots. It's as if the quantum dots emitted the chamber pitch A, whereas the wetting layer emitted an B that was a thousand times louder."

Additional layer eliminates interferences

"We have been able to ignore those interferences by exciting only the required energy states," says Matthias Löbl from the University of Basel. "However, if quantum dots are to be used as information units for quantum applications, it might be ideal to charge them with more electrons. But in that case, the energy levels in the wetting layer would be likewise excited," adds Arne Ludwig.

The research team has now eliminated this interference by adding an aluminium arsenide layer grown above the quantum dots in the wetting layer. The energy states in the wetting layer are thus removed, which, in turn, makes it less likely for electrons and electron holes to recombine and emit photons.

Collaboration between three research institutes

The samples for the current project were generated by Dr. Sven Scholz at the RUB Chair of Applied Solid State Physics, whose work was awarded with the dissertation prize by the Wilhelm and Else Heraeus Foundation in June 2019. The measurements of the size of interferences with and without the aluminium arsenide layer were conducted by the team at the University of Basel, under the auspices of Matthias Löbl, Dr. Immo Söllner and Professor Richard Warburton. The group at Forschungszentrum Jülich captured high-resolution microscope images of the samples.

Japanese scientists have found a new way to successfully detect the efficiency of crystal semiconductors. For the first time ever, the team used a specific kind of photoluminescence spectroscopy, a way to detect light, to characterize the semiconductors. The emitted light energy was used as an indicator of the crystal's quality. This method potentially culminates in more efficient light-emitting diodes (LEDs) and solar cells. Additionally, it could usher in several other advances in electronics.

The research, published in APL Materials on July 31, 2019, involves crystals called lead halide perovskites - unique types of materials with structures efficient for solar cell performance. The crystals consist of an organic material interlocked with an inorganic one. Perovskites are semiconductor materials that have many applications. They are more efficient and much easier and cheaper to make than standard commercial solar cells.

Furthermore, these promising crystals could also lead to new electronic displays, sensors and other devices that are activated by light, bringing increased efficiency at a lower cost to manufacturers of optoelectronics that harness light. In addition, these crystals have the potential to harvest solar energy. Most solar cells are made with silicon crystals, a relatively straightforward and effective material to process. However, perovskite-based devices are likely to offer higher conversion efficiencies than silicon.

"For further development of perovskite-based devices, it is essential to quantitatively evaluate the absolute efficiency in high-quality perovskite crystals without assuming any predefined physical model is of particular importance," said corresponding author Kazunobu Kojima, Associate Professor at Tohoku University, Japan. "Our method is new and unique because previous methods have relied on efficiency estimation by model-dependent analyses of photoluminescence."

Understanding photoluminescence is important for designing devices that control, generate or detect light, including solar cells, LEDs and light sensors. So far, these detections have largely relied on theoretical modelling as a way to predict the efficiency of perovskite-based semiconductors. For this research, the authors have implemented a technique they originally proposed in 2016 called Omnidirectional Photoluminescence Spectroscopy or "ODPL spectroscopy." The procedure is a contactless, nondestructive method of probing the electronic structure of the crystals from all directions, enabling them to easily and quickly quantify the crystals' properties.

An important next step is to implement ODPL spectroscopy to investigate different types of perovskite materials. This may lead to better understanding of crystal-based semiconductors as well as more efficient ones. The authors state that their future studies will focus on both increasing crystal efficiency and ensuring that it is unified across all areas of materials.

Australian medical researchers from the Centenary Institute and the University of Sydney have successfully developed and tested a new type of vaccine targeting tuberculosis (TB), the world's top infectious disease killer.

Reported in the 'Journal of Medicinal Chemistry', the early-stage vaccine was shown to provide substantial protection against TB in a pre-clinical laboratory setting.

"Tuberculosis is a huge world-wide health problem. It's caused by a bacteria that infects the lungs after it's inhaled, is contagious and results in approximately 1.6 million deaths per year globally," said Dr Anneliese Ashhurst, co-lead author of the reported study and affiliated with both the Centenary Institute and the University of Sydney.

The research program targeting the deadly disease has currently taken over five years of effort to implement. During that time Dr Ashhurst and a team of scientists have created the advanced synthetic TB vaccine and have now demonstrated its effectiveness using mouse models.

"Two peptides (small proteins) which are normally found in tuberculosis bacteria were synthesized and then bound extremely tightly to an adjuvant (a stimulant) that was able to kick-start the immune response in the lungs," said Dr Ashhurst.

"We were then able to show that when this vaccine was inhaled into the lungs, it stimulated the type of T cells known to protect against TB. Importantly, we then demonstrated that this type of vaccine could successfully protect against experimental airborne TB infection," she said.

Professor Warwick Britton, Head of the Centenary Institute Tuberculosis Research Program and co-senior researcher on the project with Professor Richard Payne, School of Chemistry, University of Sydney, emphasized the importance of the work being done.

"There currently exists only one lone vaccine for TB (known as BCG) and this is only effective in reducing the risk of disease for infants," said Professor Britton.

"It fails to prevent infection or provide long term protection in older individuals and it isn't considered suitable for use in individuals with an impaired immune system. More effective vaccines are urgently required to save lives," he said.

Professor Britton is excited that the team's vaccine strategy - directly generating immunity in the lungs - has proven to be the right research approach to take.

"The important thing is that the vaccine actually gets to the lungs because that's where you first see TB. Ultimately, we would love to see a form of this vaccine available for use in an easily inhaled nasal spray which would provide life-long TB protection. Although this outcome is still many years away, we are certainly heading in the right direction. Our next steps will be to determine if our synthetic vaccine can be developed into a form suitable for use in humans," said Professor Britton.

There are an estimated two billion individuals carrying TB globally and up to 10% of these individuals develop the disease in their lifetime. More than 50 per cent of TB cases occur in the Asia Pacific region.

A team of Australian researchers has designed a reliable strategy for testing physical abilities of humanoid robots - robots that resemble the human body shape in their build and design. Using a blend of machine learning methods and algorithms, the research team succeeded in enabling test robots to effectively react to unknown changes in the simulated environment, improving their odds of functioning in the real world.

The findings, which were published in a joint publication of the IEEE and the Chinese Association of Automation Journal of Automatica Sinica in July, have promising implications in the broad use of humanoid robots in fields such as healthcare, education, disaster response and entertainment.

"Humanoid robots have the ability to move around in many ways and thereby imitate human motions to complete complex tasks. In order to be able to do that, their stability is essential, especially under dynamic and unpredictable conditions," said corresponding author Dacheng Tao, Professor and ARC Laureate Fellow in the School of Computer Science and the Faculty of Engineering at the University of Sydney.

"We have designed a method that reliably teaches humanoid robots to be able to perform these tasks," added Tao, who is also the Inaugural Director of the UBTECH Sydney Artificial Intelligence Centre.

Humanoid robots are robots that resemble humans' physical attributes - the head, a torso, and two arms and feet - and possess the capability to communicate with humans and other robots. Equipped with sensors and other input devices, these robots also perform limited activities according to the outside input.

They are typically pre-programmed for specific activities and rely on two kinds of learning methods: model-based and model-free. The former teaches a robot a set of models that it can use to behave in a scenario, while the latter does not. While both learning methods have been successful to a certain extent, each paradigm alone has not proven sufficient to equip a humanoid robot to behave in a real-world scenario where the environment changes constantly and often unpredictably.

To overcome this, Tao and his team introduced a new learning structure that incorporates parts of both model-based and model-free learning to balance a biped, or two-legged, robot. The proposed control method bridges the gap between the two learning paradigms, where the transition from learning the model to learning the actual procedure has been smoothly completed. Simulation results show that the proposed algorithm is able to stabilize the robot on a moving platform under unknown rotations. As such, these methods demonstrate that the robots are able to adapt to different unpredictable situations accordingly and can thus be applied to robots outside of the laboratory environment.

In the future, the researchers hope to validate their method under more complex environments with more unpredictable and changing variables and with varying dimensions as they test the robots' abilities to exert full body control.

"Our ultimate goal will be to see how our method enables the robot to have control over its entire body as it is exposed to unmeasurable and unexpected disturbances such as a changing terrain. We would also like to see the robot's ability to learn how to imitate human motion, such as ankle joint movement, without having been given prior information."

How do cells generate and use energy? This question might seem simple, but the answer is far from simple. Furthermore, knowing how microbial cell factories consume energy and how proteins are allocated to do so is crucial when working with industrial fermentations.

Now, researchers have shown that it is possible to evoke a shift in the metabolism from fermentation to respiration of E. coli and baker's yeast by optimizing fermentation conditions. This shift means that the cells can be pushed into producing more internal energy (ATP).

"This information can be used to design new, improved cell factories," corresponding author Professor at Chalmers University of Technology, Sweden, and Scientific Director at The Novo Nordisk Foundation Center for Biosustainability at DTU in Denmark Jens Nielsen says.

Together with first-author Postdoc Yu Chen from Department of Biology and Biological Engineering at Chalmers, Jens Nielsen has studied the metabolism of E. coli and baker's yeast through the use of mathematical models and biological experiments. The research has now been published in Proceedings of the National Academy of Sciences (PNAS).

Cells constantly generate high-energy molecules called ATP from the sugar glucose. ATP is the cellular "food" consumed by the workers - enzymes - within cells. The enzymes use this energy to build biomass or do other cellular work. The more ATP available, the better the microbial workhorses perform in fermentations; at least in principle - many other aspects play a part as well.

Using a computational approach, the researchers found out that ATP can be generated by either of two pathways: a high-yielding respiratory pathway resulting in 23.5 ATP's per glucose molecule or a low-yielding fermentative pathway, which only generates 11 ATP's per glucose molecule.

The two pathways supplement each other, but the researchers were able to shift the natural balance between the two by changing the conditions of the fermentation and the amount of sugar and protein available. Furthermore, they showed that the high-yielding pathway needs more protein mass than the low-yielding pathway for consuming glucose at the same rate.

They also showed that making some key enzymes perform better meant that the cells changed from doing low yielding fermentative metabolism to breathing through the high yielding respiratory metabolism.

This shift both results in more intracellular ATP, but also avoids the build-up of fermentative byproducts; acetate in E. coli and ethanol in baker's yeast.

"These byproducts are unwanted and decrease the yield of the sought-for molecules you want to produce in your cell factory," says Jens Nielsen.

Furthermore, the investigators showed that cells performing their best actually used both pathways, not only the high yielding one, and that more proteins available meant more efficiency in a given pathway.

So, the solution to better performing cells in fermentations is not to switch off the fermentative pathway, but rather to allocate more protein to the high-yielding pathway.

The researchers solely exposed the microbes to different fermentation conditions and didn't do genome engineering to evoke these changes. But at the same time, their studies gave an indication of how one can change the cells' metabolism by genome engineering to become more effective in future experiments.

Japanese scientists at Tokyo University of Agriculture and Technology (TUAT) have found that for stroke patients, observing their own hand movements in a video-assisted therapy - as opposed to someone else's hand - could enhance brain activity and speed up rehabilitation.

Their findings were first made available online in May and published in the July 7, 2019 issue of IEEE Transactions on Neural Systems and Rehabilitation Engineering.

A stroke is caused by obstruction of blood flow to the brain and can leave a patient paralyzed. Brain plasticity, where a healthy region of the brain fulfills the function of a damaged region of the brain, is a key factor in the recovery of motor functions caused by stroke. Studies have shown that sensory stimulation of the neural pathways that control the sense of touch can promote brain plasticity, essentially rewiring the brain to regain movement and senses.

To promote brain plasticity, stroke patients may incorporate a technique called motor imagery in their therapy. Motor imagery allows a participant to mentally simulate a given action by imagining themselves going through the motions of performing that activity. This therapy may be enhanced by a brain-computer interface technology, which detects and records the patients' motor intention while they observe the action of their own hand or the hand of another person.

"We set out to determine whether it makes a difference if the participant is observing their own hand or that of another person while they're imagining themselves performing the task," said co-author Toshihisa Tanaka, a professor in the Department of Electrical and Electrical Engineering at TUAT in Japan and a researcher at the RIKEN Center for Brain Science and the RIKEN Center for Advanced Intelligent Project.

The researchers monitored brain activity of 15 healthy right-handed male participants under three different scenarios. In the first scenario, participants were asked to imagine their hand moving in synchrony with hand movements being displayed in a video clip showing their own hand performing the task, together with corresponding voice cues. In the second scenario, they were asked to imagine their hand moving in synchrony with hand movements being displayed on a video clip showing another person's hand performing the task, together with voice cues. In the third scenario, the participants were asked to open and close their hands in response to voice cues only. Using electroencephalography (EEG) -- a non-invasive method of measuring electrical brain activity where electrodes are placed on the scalp --brain activity of the participants was observed as they performed each task.

The team found meaningful differences in EEG measurements when participants were observing their own hand movement and that of another person. The findings suggest that, in order for motor imagery-based therapy to be most effective, video footage of a patient's own hand should be used.

"Visual tasks where a patient observes their own hand movement can be incorporated into brain-computer interface technology used for stroke rehabilitation that estimates a patient's motor intention from variations in brain activity, as it can give the patient both visual and sense of movement feedback," Tanaka explains.

The nanostructures from Katja Höflich's HZB team are shaped like corkscrews and made of silver. Mathematically, such a nano antenna can be regarded as an one-dimensional line that forms a helix, characterized by parameters such as diameter, length, number of turns per unit length, and handedness.

The nano corkscrews are highly sensitive to light: depending on frequency and polarisation, they can strongly enhance it. Because helical antennas have a handedness, they can select light quanta according to their handedness, i.e. their spin. This results in novel applications in information technology based on the spin quantum number of light. Another application may lay in sensor technology in detecting chiral molecular species down to the single molecule level.

Usually, the interaction of such nano-antennas with an electromagnetic field is determined using numerical methods. Each helix geometry, however, requires a new numerically expensive calculation.

For the first time, Höflich and her team have now derived an analytically exact solution of the problem. "We now have a formula that tells us how a nano-antenna with specific parameters responds to light", says Höflich. This analytical description can be used as a design tool, as it specifies the required geometrical parameters of a nano-helix to amplify electromagnetic fields of desired frequencies or polarisation.

The HZB researchers were able to fabricate nano-antennae in an electron microscope by using direct electron-beam writing. The electron beam first writes a helix-shaped carbon structure one point at a time. This structure is subsequently coated with silver. The actual measurements of the optical properties for these silver nano-antennae are in good agreement with the calculated properties predicted by the analytical model.

A sophisticated chip the size of a coin in which cartilage can be cultivated and which can later be subjected to mechanical stress such that it generates the effects of Osteoarthrosis (OA).
This is the extraordinary result achieved at the Politecnico di Milano Laboratory MiMic (Microfluidic and Biomimetic Microsystems) by Marco Rasponi from the Milan-based campus, the study's coordinator alongside Andrea Barbero from the University Hospital of Basel.

The study was published in Nature Biomedical Engineering.

Not only did it produce the revolutionary chip but, while the tiny device was undergoing experimentation, the study also demonstrated that the mechanical hyperstimulation of cartilage seems to be enough to induce Osteoarthrosis-related pathology, without having to turn to administering inflammatory molecules as was common practice up until now.

Indeed, appropriate compression of the cartilaginous tissue can induce typical symptoms of OA: inflammation, hypertrophy and an acceleration of degenerative processes. Therefore, in the cartilage "on a chip" an ideal environment is created in which to test the effectiveness and mechanisms of pharmacological treatments, shortening the timeframes and costs of experimentation while also reducing the need for animal testing.

Osteoarthrosis is the most common among musculoskeletal pathologies. Over the age of sixty, 10% of men and 20% of women will suffer from its effects, numbers which unfortunately are set to increase due to the current rate of population ageing. However, despite this trend, patients find themselves facing a complete lack of pharmacological therapy, known as DMOADs (Disease modifying Osteoarthritis Drugs): pharmaceuticals, that is, which are capable of not only alleviating the symptoms but also halting or reversing the degenerative processes. In fact, currently the only valid options are palliative treatment or surgery.

The development of effective drugs was hindered by an absence of experimental models that could adequately replicate the pathology.

Up until now the most common approach to reproduce OA in vitro has been based on administering high doses of molecules into cartilage explants, capable of inducing an inflammatory response and some form of catabolism. Yet the OA obtained in this manner can only partially represent the final symptoms, instead of demonstrating the pathological process in real time. The new chip, on the other hand, uses mechanical stress, representing one of the factors that are most closely connected to the development of OA, and is thus more realistic and more effective in its development and pharmacological screening procedures.

The research will continue towards modelling an entire joint on a chip, thanks to a project initiated by the Cariplo Foundation, having been granted funding following the call for "Biomedical research on age-related diseases 2018". The project is named "uKNEEque: a 3D microfluidic osteochondral model to investigate mechanisms triggering age-related joint pathologies and therapeutic effects of bioactive factors produced by nasal chondrocytes". The Politecnico di Milano is coordinating the research with the University Hospital of Basel as a Partner.

In the first continent-wide genomic study of malaria parasites in Africa, scientists have uncovered the genetic features of Plasmodium falciparum parasites that inhabit different regions of the continent, including the genetic factors that confer resistance to anti-malarial drugs. This sheds new light on the way that drug resistance is emerging in different locations and moving by various routes across Africa, putting previous success in controlling malaria at risk.

The research, published today (22 August) in Science, comes from the first network of African scientists, the Plasmodium Diversity Network Africa (PDNA), to work with genomic tools to study the diversity of malaria parasites across the continent. In collaboration with the Wellcome Sanger Institute, the researchers studied the genetic diversity of P. falciparum populations endemic to several countries in sub-Saharan Africa, including Ethiopia and Ghana. Genomic surveillance data will help to track the emergence and spread of drug-resistant strains, assisting efforts to eliminate malaria.

Malaria remains a global problem, with the deadliest parasite species P. falciparum prevalent across sub-Saharan Africa. Between 2000 and 2015, an ongoing drive to eliminate the disease has seen worldwide malaria deaths halve from 864,000 to 429,000 per year. In 2015, 92 per cent of global malaria deaths were in Africa, with 74 per cent of these occurring in children under five years of age.* But the findings of a new study suggest this progress may be at risk if new forms of treatment aren't developed.

Although the population of P. falciparum parasites in sub-Saharan Africa is extremely genetically diverse, previous research suggested that this diversity was relatively similar across the continent. It was also thought that the flow of genetic material tended to be from east to west, with resistance to antimalarial drugs believed to originate in South East Asia.

The results of this new study indicate, however, that P. falciparum parasites are genetically distinct according to which region of Africa they are found. Furthermore, researchers found that these regional populations are sharing genetic material in all directions - including genes that can confer resistance to antimalarial drugs, with new types of drug resistance emerging in different parts of Africa. It is thought human migration, including that resulting from colonial activity, has played a part in the evolution of P. falciparum in Africa.

Samples of P. falciparum were collected from 15 African countries by PDNA and their genomes sequenced at the Wellcome Sanger Institute as part of the MalariaGEN data-sharing network**. The genetic data on these samples, along with other African data that have previously been generated and openly released by MalariaGEN, were analysed to trace ancestral connectivity between the various parasite populations.

Professor Abdoulaye Djimdé, Wellcome International Fellow at the Wellcome Sanger Institute and Chief of the Molecular Epidemiology and Drug Resistance Unit at the Malaria Research and Training Centre, University of Bamako, said: "Contrary to previous studies, we identified distinct Western, Central and Eastern populations of P. falciparum, as well as a highly-divergent Ethiopian population. Genetic material originating from all directions was shared by all populations, indicating that the flow of genes is multi-directional, as opposed to unidirectional from east to west as previously thought. This is crucial information for understanding how resistance to malaria drugs is developing in Africa."

Researchers noted the fact that the Ethiopian parasite population is highly-differentiated from those in the rest of Africa, which suggested the ancestry of malaria parasites may have been influenced by human migration. The human population in Ethiopia also has a distinct ancestry to others in Africa, suggesting that the lack of colonization of the country might explain its outlier status. By contrast, parasites from distant former French colonies share genetic material.

The results confirmed that populations of P. falciparum have shared genetic information over time, particularly genes associated with resistance to antimalarial drugs.

Most concerningly, strong genetic signatures were detected on chromosome 12 in P. falciparum samples from Ghana and Malawi, raising the possibility that recent evolution of the parasite could compromise the effectiveness of artemisinin-based combination therapies (ACTs). ACTs combine multiple antimalarial drugs in one treatment to overcome resistance to one or more individual drugs.

Dr Alfred Amambua-Ngwa, first author of the study, a Wellcome International Fellow at the Wellcome Sanger Institute and Assistant Professor at the Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, said: "Whatever the historic factors affecting the flow of genes between the distinct P. falciparum populations, the multi-directional flow we've identified raises the prospect of continental spread of resistance to artemisinin-based combination therapies, which could arise from anywhere in Africa. Genomic surveillance, and on a large scale, is going to be vital to track the emergence and spread of resistance to combination therapies."

The establishment of the PDNA is an important step in continuing to track the spread of drug-resistant malaria in Africa at a crucial time, when efforts to eliminate the disease are now stalling and the prospect of multi-drug resistant strains of P. falciparum in Africa on the horizon.

Professor Dominic Kwiatkowski, Head of the Parasites and Microbes Programme at the Wellcome Sanger Institute, and Director of the MRC Centre for Genomics and Global Health, said: "Back in 2013, this impressive team of African scientists recognised the need to work together across the continent to monitor how this deadly malaria parasite is evolving. This has involved many practical and logistical challenges, and the team have done an amazing job in pulling together the most comprehensive genetic picture of the parasite population in different parts of Africa. It proves the feasibility of using modern genomic technologies to monitor malaria drug resistance in Africa, and it is now extremely important to ensure that the work is continued and used by policymakers and public health agencies to guide sustainable strategies for disease control."

Michael Chew, Infection and Immunobiology Portfolio Manager at Wellcome, said: "This research could have implications for the future of malaria research and control in sub-Sahara Africa. By studying the genetic diversity of malaria across such a vast and diverse area, the research team have revealed the presence of key genetic differences within the malaria parasite P. falciparum strains across Africa.

"This could provide vital information into how drug-resistance is developing across the region and provides a stark reminder that the progress made in tackling malaria in sub-Sahara Africa is at risk of stalling unless we can develop new and effective treatments."

(BOSTON) -- The CRISPR-Cas system has become the go-to tool for researchers who study genes in an ever-growing list of organisms, and is being used to develop new gene therapies that potentially can correct a defect at a single nucleotide position of the vast reaches of the genome. It is also being harnessed in ongoing diagnostic approaches for the detection of pathogens and disease-causing mutations in patients.

Now, reporting in Science, a research team at Harvard's Wyss Institute for Biologically Inspired Engineering and the Massachusetts Institute of Technology (MIT) demonstrates the use of CRISPR as a control element in a new type of stimuli-responsive "smart" materials. Upon activation by specific natural or user-defined DNA stimuli, a CRISPR-Cas enzyme enables a variety of smart materials to release bound cargo such as fluorescent dyes and active enzymes, change their structures to deploy encapsulated nanoparticles and live cells, or regulate electric circuits thereby converting biological into electric signals.

"Our study shows that the power of CRISPR can be harnessed outside of the laboratory for controlling the behavior of DNA-responsive materials. We developed a range of materials with very different capabilities that highlight the breadth of applications enabled by programmable CRISPR-responsive smart materials," said Wyss Institute Founding Core Faculty member James Collins, Ph.D., who led the study and is a leader of the Institute's Living Cellular Devices platform. "These applications include novel theranostic strategies, point-of-care diagnostics, and the regional monitoring of epidemic outbreaks and environmental hazards." Collins also is the Termeer Professor of Medical Engineering & Science and a Professor of Biological Engineering at MIT.

The CRISPR-Cas system has gained its fame because of its ability to find almost any target sequence in the genome with the help of a short complementary guide-RNA (gRNA), and to cut and repair the DNA double strand with surgical precision. In the present study, the team leveraged a Cas enzyme variant known as Cas12a from a Lachnospiraceae bacterium that has the same ability to recognize and cut specific DNA sequences but, activated by this event, importantly, carries on to non-specifically cleave single-stranded DNA in its vicinity at a rate of about 1250 turnovers per second.

"We incorporated single-stranded target DNA sequences into polymeric materials, either as anchors for pendant cargos, or as structural elements that maintain the materials' basic integrity, and can control different material behaviors just by providing Cas12a together with a specific gRNA as a stimulus," said co-first author Max English, who is an MIT graduate student working with Collins.

CRISPR-responsive materials for small cargo delivery

In one variation of their concept, the researchers attached different payloads via double-stranded DNA anchor sequences to a so-called poly(ethylene glycol) hydrogel material. "The anchor sequences are targeted by nearby Cas12a enzymes in the presence of complementary gRNAs, and are then degraded," said co-first author Helena de Puig, Ph.D., a post-doctoral researcher on Collins' team. "As a result, we can release payloads like fluorescent molecules and enzymes at rates that depend on the relative affinities of gRNA/target DNA pairs, as well as properties hard-coded into the gels, such as their pore sizes, and the densities of targeted anchor sequences cross-linked to the gel material." The authors think that this approach could be used, for example, to develop materials with diagnostic capabilities and for environmental monitoring.

Stimulated release of encapsulated nanoparticles and cells

At larger scales, the team investigated their approach for prompting structural changes in polyacrylamide hydrogels (PA) that encapsulated nanoparticles and live cells. "Here, we used Cas12a target sequences to cross-link PA strands to each other and thus to function as structural elements. Removing the cross-linkers by triggering Cas12a activity stimulates mechanical changes throughout the entire gel matrix, which allowed gold nanoparticles and human primary cells to be released," said Raphael Gayet, another co-first author and graduate student in Collins group. "This approach could be utilized to release cells into tissue scaffolds."

Biomaterials as electric fuses and controllable valves

On yet a different avenue, Collins and his team engineered CRISPR-responsive smart materials that can act as electric fuses and controllable valves regulating the passage of fluids. The researchers covered electrodes with a mixture of nanoparticles made of carbon black, a good conductor of electricity, and random single-stranded DNA fragments, and surrounded the electrodes with a solution containing Cas12a and a specific double-stranded target DNA. "The material by itself enabled an electric current to run between the electrodes. However, when we triggered Cas12a-dependent degradation of the embedded DNA, the material became disrupted and the current interrupted," said co-author Nicolaas Angenent-Mari from Collins' team.

In paper-based microfluidic devices, the team assembled a stack of folded micro-pads that each carried out a specific function. They pre-reacted a DNA cross-linked PA gel with Cas12a in the absence or presence of a Cas12a-specific double-stranded DNA trigger and covered a middle pad with it. However, the gel formed only in the absence of a Cas12a-triggering DNA, and when applied to the pad, clogged its pores. This in turn blocked the flow of a buffer carrying electrolytes from the top to the bottom of the stack where an electrode was located. In contrast, the presence of a Cas12a-triggering DNA prevented the gel to be cross-linked and thus enabled the buffer to flow and cause a current across the electrode, essentially acting as a resistor. "With this approach, we coupled the detection of DNA corresponding to ebola virus-specific RNA with an electric signal and even transmit the signal with a coupled RFID antenna in real time," said Luis Soenksen, also a co-first author on the study.

"This breakthrough study by James Collins and his team in the Wyss Institute's Living Cellular Devices platform demonstrates the value of CRISPR technology for entirely new fields, ranging from diagnostics and theragnostics to bioelectronics, and marks yet another inspiring inflection point for biomedical developments enabled by this bioinspired technology," said Wyss Institute Founding Director Donald Ingber, M.D., Ph.D., who is also the Judah Folkman Professor of Vascular Biology at HMS, the Vascular Biology Program at Boston Children's Hospital, and Professor of Bioengineering at Harvard's John A. Paulson School of Engineering and Applied Sciences (SEAS).

Storm clouds rooted deep in Jupiter's atmosphere are affecting the planet's white zones and colorful belts, creating disturbances in their flow and even changing their color.

Thanks to coordinated observations of the planet in January 2017 by six ground-based optical and radio telescopes and NASA's Hubble Space Telescope, a University of California, Berkeley, astronomer and her colleagues have been able to track the effects of these storms -- visible as bright plumes above the planet's ammonia ice clouds -- on the belts in which they appear.

The observations will ultimately help planetary scientists understand the complex atmospheric dynamics on Jupiter, which, with its Great Red Spot and colorful, layer cake-like bands, make it one of the most beautiful and changeable of the giant gas planets in the solar system.

One such plume was noticed by amateur astronomer Phil Miles in Australia a few days before the first observations by the Atacama Large Millimeter/Submillimeter Array (ALMA) in Chile, and photos captured a week later by Hubble showed that the plume had spawned a second plume and left a downstream disturbance in the band of clouds, the South Equatorial Belt. The rising plumes then interacted with Jupiter's powerful winds, which stretched the clouds east and west from their point of origin.

Three months earlier, four bright spots were seen slightly north of the North Equatorial Belt. Though those plumes had disappeared by 2017, the belt had since widened northward, and its northern edge had changed color from white to orangish brown.

"If these plumes are vigorous and continue to have convective events, they may disturb one of these entire bands over time, though it may take a few months," said study leader Imke de Pater, a UC Berkeley professor emerita of astronomy. "With these observations, we see one plume in progress and the aftereffects of the others."

The analysis of the plumes supports the theory that they originate about 80 kilometers below the cloud tops at a place dominated by clouds of liquid water. A paper describing the results has been accepted for publication in the Astronomical Journal and is now online.

Into the stratosphere

Jupiter's atmosphere is mostly hydrogen and helium, with trace amounts of methane, ammonia, hydrogen sulfide and water. The top-most cloud layer is made up of ammonia ice and comprises the brown belts and white zones we see with the naked eye. Below this outer cloud layer sits a layer of solid ammonium hydrosulfide particles. Deeper still, at around 80 kilometers below the upper cloud deck, is a layer of liquid water droplets.

The storm clouds de Pater and her team studied appear in the belts and zones as bright plumes and behave much like the cumulonimbus clouds that precede thunderstorms on Earth. Jupiter's storm clouds, like those on Earth, are often accompanied by lightning.

Optical observations cannot see below the ammonia clouds, however, so de Pater and her team have been probing deeper with radio telescopes, including ALMA and also the Very Large Array (VLA) in New Mexico, which is operated by the National Science Foundation-funded National Radio Astronomy Observatory.

ALMA array's first observations of Jupiter were between Jan. 3 and 5 of 2017, a few days after one of these bright plumes was seen by amateur astronomers in the planet's South Equatorial Belt. A week later, Hubble, the VLA, the Gemini, Keck and Subaru observatories in Hawaii and the Very Large Telescope (VLT) in Chile captured images in the visible, radio and mid-infrared ranges.

De Pater combined the ALMA radio observations with the other data, focused specifically on the newly brewed storm as it punched through the upper deck clouds of ammonia ice.

The data showed that these storm clouds reached as high as the tropopause -- the coldest part of the atmosphere -- where they spread out much like the anvil-shaped cumulonimbus clouds that generate lightning and thunder on Earth.

"Our ALMA observations are the first to show that high concentrations of ammonia gas are brought up during an energetic eruption," de Pater said.

The observations are consistent with one theory, called moist convection, about how these plumes form. According to this theory, convection brings a mix of ammonia and water vapor high enough -- about 80 kilometers below the cloud tops -- for the water to condense into liquid droplets. The condensing water releases heat that expands the cloud and buoys it quickly upward through other cloud layers, ultimately breaking through the ammonia ice clouds at the top of the atmosphere.

The plume's momentum carries the supercooled ammonia cloud above the existing ammonia-ice clouds until the ammonia freezes, creating a bright, white plume that stands out against the colorful bands encircling Jupiter.

"We were really lucky with these data, because they were taken just a few days after amateur astronomers found a bright plume in the South Equatorial Belt," said de Pater. "With ALMA, we observed the whole planet and saw that plume, and since ALMA probes below the cloud layers, we could actually see what was going on below the ammonia clouds."

Hubble took images a week after ALMA and captured two separate bright spots, which suggests that the plumes originate from the same source and are carried eastward by the high altitude jet stream, leading to the large disturbances seen in the belt.

Coincidentally, three months before, bright plumes had been observed north of the Northern Equatorial Belt. The January 2017 observations showed that that belt had expanded in width, and the band where the plumes had first been seen turned from white to orange. De Pater suspects that the northward expansion of the North Equatorial Belt is a result of gas from the ammonia-depleted plumes falling back into the deeper atmosphere.

De Pater's colleague and co-author Robert Sault of the University of Melbourne in Australia used special computer software to analyze the ALMA data to obtain radio maps of the surface that are comparable to visible-light photos taken by Hubble.

"Jupiter's rotation once every 10 hours usually blurs radio maps, because these maps take many hours to observe," Sault said. "In addition, because of Jupiter's large size, we had to 'scan' the planet, so we could make a large mosaic in the end. We developed a technique to construct a full map of the planet."

Swirling clouds, big colorful belts, giant storms -- the beautiful and turbulent atmosphere of Jupiter has been showcased many times. But what is going on below the clouds? What is causing the many storms and eruptions that we see on the 'surface' of the planet? To see this, visible light is not enough. We need to study Jupiter using radio waves.

New radio wave images made with the Atacama Large Millimeter/submillimeter Array (ALMA)
provide a unique view of Jupiter's atmosphere down to fifty kilometers below the planet's visible (ammonia) cloud deck.

"ALMA enabled us to make a three-dimensional map of the distribution of ammonia gas below the clouds. And for the first time, we were able to study the atmosphere below the ammonia cloud layers after an energetic eruption on Jupiter," said Imke de Pater of the University of California, Berkeley.

The atmosphere of gas giant Jupiter is made out of mostly hydrogen and helium, together with trace gases of methane, ammonia, hydrogen sulfide and water. The top-most cloud layer is made up of ammonia ice. Below that is a layer of solid ammonium hydrosulfide particles, and deeper still, around 80 kilometers below the upper cloud deck, there likely is a cloud layer of liquid water. Variations in the upper clouds form the distinctive brown belts and white zones seen from Earth.

Many of the storms on Jupiter take place inside those belts. They can be compared to thunderstorms on Earth and are often associated with lightning events. Storms reveal themselves in visible light as small bright clouds, referred to as plumes. These plume eruptions can cause a major disruption of the belt, which can be visible for months or years.

The ALMA images were taken a few days after amateur astronomers observed an eruption in Jupiter's South Equatorial Belt in January 2017. A small bright white plume was visible first and then a large-scale disruption in the belt was observed that lasted for weeks after the eruption.

De Pater and her colleagues used ALMA to study the atmosphere below the plume and the disrupted belt at radio wavelengths and compared these to UV-visible light and infrared images made with other telescopes at approximately the same time.

"Our ALMA observations are the first to show that high concentrations of ammonia gas are brought up during an energetic eruption," said de Pater. "The combination of observations simultaneously at many different wavelengths enabled us to examine the eruption in detail. This led us to confirm the current theory that energetic plumes are triggered by moist convection at the base of water clouds, which are located deep in the atmosphere. The plumes bring up ammonia gas from deep in the atmosphere to high altitudes, well above the main ammonia cloud deck," she added.

"These ALMA maps at millimeter wavelengths complement the maps made with the National Science Foundation's Very Large Array in centimeter wavelengths," said Bryan Butler of the National Radio Astronomy Observatory. "Both maps probe below the cloud layers seen at optical wavelengths, and show ammonia-rich gases rising into and forming the upper cloud layers (zones), and ammonia-poor air sinking down (belts)."

Over the last day, winds outside of Tropical Storm Chantal have been weakening the storm in the North Atlantic Ocean. When NASA's Aqua satellite passed over the storm from its orbit in space on August 22, the storm had weakened to a depression and strongest storms were still confined to the northeast of the center.

On Aug. 22 at 12:45 a.m. EDT (0445 UTC), the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite used infrared light to analyze the strength of storms by providing temperature information about the system's clouds. The strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.

The strongest storms were still east of the center of circulation, although they shifted to the northeast today. That displacement of strongest storms from around the center is indicative of vertical wind shear, outside westerly winds pushing against the storm. Storms east of the center had cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6 Celsius).

In general, wind shear is a measure of how the speed and direction of winds change with altitude. Tropical cyclones are like rotating cylinders of winds. Each level needs to be stacked on top of each other vertically in order for the storm to maintain strength or intensify. Wind shear occurs when winds at different levels of the atmosphere push against the rotating cylinder of winds, weakening the rotation by pushing it apart at different levels.

At 5 a.m. EDT (0900 UTC), the center of Tropical Storm Chantal was located near latitude 39.1 degrees north and longitude 45.7 degrees west. The center of Chantal is about 645 miles (1,035 km) southeast of Cape Race, Newfoundland, Canada. The depression is moving toward the east near 17 mph (28 kph). Chantal is forecast to slow down and make a clockwise loop through the weekend. Maximum sustained winds are near 35 mph (55 kph) with higher gusts. The estimated minimum central pressure is 1010 millibars.

NOAA's National Hurricane Center noted that weakening is expected, and Chantal is forecast to degenerate into a remnant low pressure area by Friday, August 23.

August 22, 2019--Exposure to the criminal justice system increases some of the risk factors used to predict recidivism and re-arrest, according to new research out of Columbia University Mailman School of Public Health. For every arrest or conviction an adolescent experienced, their levels of antisocial attitudes, behaviors, and number of peers became subsequently higher. Findings provide new empirical evidence for an old claim--that exposure to the criminal justice system criminalizes people further. Results raise concerns about transporting risk assessments for predicting recidivism to other points in the criminal justice system. Findings are online in the journal Law and Human Behavior.

While "criminogenic" risk assessment is considered an evidence-based practice for predicting recidivism, that evidence comes entirely from people who are already entrenched in the criminal justice system. These latest findings show that it would be inappropriate to use the same risk assessments on people who haven't been exposed to the criminal justice system.

"Risk assessment, and algorithmic prediction more broadly, is being heralded as a key component of criminal justice reform," said Seth J. Prins, PhD assistant professor of Epidemiology and Sociomedical Sciences and author of the study. "But these findings suggest that current risk assessments cannot fully distinguish between individuals' propensities and the fact that they have already been criminalized by a runaway criminal justice system."

Data for the analysis came from 500 boys followed from ages 7 to 28, recruited from all public schools in downtown Pittsburgh in the late 1980s. In each survey wave, they were asked about their attitudes toward delinquent behaviors such as stealing, vandalism, fighting, and drug selling. They were also asked how many times they had engaged in those behaviors, and how many of their friends engaged in those behaviors.

Prins used a combination of techniques to rule out alternative explanations for his findings. He estimated the cumulative effect of arrests and convictions, respectively, on adolescents' antisocial attitudes, behaviors, and peers, respectively. He controlled for a host of other factors including demographics; school performance; mental health; parental supervision, stress, and conviction history; and neighborhood characteristics. He also estimated the effect of an arrest or conviction in the prior survey wave on subsequent antisocial characteristics, with models that controlled even for unmeasured stable factors.

"Some proponents of risk assessment claim that it taps into the origins of crime," said Prins, "but in the era of mass incarceration, the idea that risk factors for staying trapped in the criminal justice system are the same as the risk factors for initial exposure to the system ignores all the social, economic, and policy-related factors that have nothing to do with individual characteristics. We need to focus on what puts people at risk of criminogenic risk, and one of those things, arguably, is current criminal justice policy."