What Is The Influence Of Laser Treatment On the Corrosion Resistance of Cermet Coating? (Material Science)

Anna Goral and colleagues investigated the influence of laser treatment on the corrosion resistance of the Cr3C2-25(Ni20Cr) cermet coating on the Al7075 substrate. They showed that laser treatment has a significant influence on the surface structure of the cermet coatings. For the lowest laser spot speed (i.e., 600 mm/min), they obtained the flattest and compact cermet surface on the Al7075 substrate. While, the corrosion rate was also reduced by more than two times compared to highest speed of laser spot. Their study recently appeared in the Journal Materials.

Cold sprayed is a coating deposition method. In this method, solid powders are accelerated in a supersonic gas jet to velocities up to 1200 m/s. During impact with the substrate, particles undergo plastic deformation and adhere to the surface, thereby forming a continuous coating.

The Al7075 alloy is a high-strength aluminum alloy that is comparable to many types of steel; it is applicable as aircraft fittings, shafts, gears valve components, and many other structural parts. However, this alloy has lower corrosion resistance than other aluminum alloys. This issue can be solved by the development of the ceramic coating with the improved corrosion resistance of the Al7075 alloy.

Now, Anna Goral and colleagues investigated the influence of laser treatment on the corrosion resistance of the Cr3C2-25(Ni20Cr) cermet coating on the Al7075 substrate (Cr3C2-25(Ni20Cr)/Al7075).

They first produced the Cr3C2-25(Ni20Cr)/Al7075 coatings by the cold sprayed (CS) method. Later, these coatings were irradiated with a laser spot speed of 600 mm/min, 800 mm/min, and 1000 mm/min. Finally, the Cr3C2-25(Ni20Cr)/Al7075 surface was subjected to the corrosion test in an acid chloride solution (1.2 M Cl¯). The exposure time of the specimen was five hours.

They showed that laser treatment has a significant influence on the surface structure of the cermet coatings. For the lowest speed (i.e., 600 mm/min), the flattest, regular, and compact cermet surface on the Al7075 substrate was obtained. However, the Vickers microhardness of the cermet coatings was decreased as the speed of laser irradiation was increased.

Table 1: Polarization resistance of the Cr3C2-25(Ni20Cr) cermet coatings on the Al7075 substrate without and with laser remelting. © Anna Goral et al.
Table 2: Corrosion rate of the Cr3C2-25(Ni20Cr) cermet coatings on the Al7075 substrate without and with laser remelting. © Anna Goral et al.

They also observed highest polarization resistance, thus, lowest corrosion damage (i.e. only 0.46 CR mm/year, as shown in Table 1 & 2 above) for the Cr3C2-25(Ni20Cr)/Al7075 surface, which was subjected to laser processing with a laser spot speed of 600 mm/min. In this case, the Cr3C2-25(Ni20Cr) coating was hardened and sealed as a result of the laser treatment, and the corrosion process of the investigated material was significantly slowed down. Thus, the Cr3C2-25(Ni20Cr) coating protects the Al7075 substrate well against contact with a corrosion environment, i.e., 1.2 M Cl¯.

On the other hand, for the higher laser spot speed, i.e., 800 mm/min or 1000 mm/min were much greater damage to the Cr3C2-25(Ni20Cr)/Al7075 surfaces due to corrosion in the aggressive environment of chloride. Meaning, for the higher speeds, laser treatment significantly reduces the mechanical and anti-corrosion properties of the cermet coatings.

Figure 1: MO images of the Cr3C2-25(Ni20Cr) cermet coatings on the Al7075 substrate after laser remelting for the spot speed: (a) 600 mm/min, (b) 800 mm/min, and (c) 1000 mm/min in 1.2 M Cl¯ pH 1.5. Exposure time was five hours. (Corrosion damages are marked in red) © Anna Goral et al.

Featured image: Structure of the Cr3C2-25(Ni20Cr) cermet coating on the Al7075 substrate after laser remelting for the spot speed of 600 mm/min: coating topography © Anna Goral et al.

Reference: Scendo, M.; Zorawski, W.; Staszewska-Samson, K.; Goral, A. Influence of Laser Treatment on the Corrosion Resistance of Cr3C2-25(Ni20Cr) Cermet Coating. Materials 2021, 14, 4078. https://doi.org/10.3390/ma14154078

Note for editors of other websites: To reuse this article fully or partially kindly give credit either to our author/editor S. Aman or provide a link of our article

Cognitive Decline May Help Predict Future Fracture Risk in Women (Medicine)

A 16-year study has revealed a link between cognitive decline, bone loss and fracture risk in women.

Researchers led by the Garvan Institute of Medical Research have discovered a link between cognitive decline and a faster rate of bone loss, and found that cognitive decline over five years increased future fracture risk in women. The association between cognitive decline and bone loss was weaker in men.

The study of individuals aged 65 and older was carried out over 16 years and has revealed a potential new approach to help identify older people who may be at risk of fracture.

“Bone loss and cognitive decline are major public health issues, but both are ‘silent diseases’ that can go undetected and untreated for long periods, often until the conditions are severely progressed,” says Professor Jacqueline Center, Head of the Clinical Studies and Epidemiology lab at Garvan, endocrinologist at St Vincent’s Hospital and senior author of the findings published in the Journal of Bone and Mineral Research.

“Our study has revealed a link between the two in women, which suggests that cognition should be monitored together with bone health, as a decline in one could mean a decline in the other. These findings may help refine best practice guidelines of how cognition and bone health are monitored in older age, to ensure appropriate treatment can be more effectively administered.”

New insights on major public health issues

Around the world, 200 million people are affected by osteoporosis and more than 35 million by dementia – numbers which are expected to double over the next two decades due to a global increase in life expectancy.

“Cognitive decline and bone loss both result in increased disability, loss of independence and an increased risk of mortality. There is some evidence that older individuals with dementia have a higher risk of hip fractures, but whether the decline of both bone and cognitive health are linked over time has not been studied,” says Dr Dana Bliuc from the Garvan Institute, who is first author of the paper.

“We set out to understand the long-term association, with our study the first to investigate both cognitive and bone health data over more than 15 years.”

The team used data from the Canadian Multicentre Osteoporosis Study (CaMos), which documented skeletal health in people living in the community since 1995. The researchers looked at cognitive and bone health measurements of 1741 women and 620 men aged 65 years and older, who had no symptoms of cognitive decline at the beginning of the study.

Linking cognition and bone health

“After adjusting for all other variables, we observed a significant link between a decline in cognitive health and bone loss in women. This association was weaker and not statistically significant in men,” says Dr Bliuc.

“Interestingly, we also saw that cognitive decline over the first five years was associated with a 1.7-fold increase in future fracture risk in women in the subsequent 10 years. This was independent of the level of bone loss,” adds Dr Bliuc.

“While this study could not identify a causal link – whether a decline in cognitive function leads to a decline in bone loss, or vice versa – it suggests that cognitive decline should be monitored along with bone health, as a decline in one may signal the need for increased vigilance in the other,” says Professor Center.

The researchers add that the link could potentially be mediated by a third factor, such as estrogen deficiency, which affects women after menopause and has been independently associated with both bone loss and cognitive decline. This research also opens the door for additional studies into what the link between these two common conditions may be.

“What our study highlights is that cognitive health is potentially an important factor for providing more information to individuals and their health professionals on fracture risk, and ultimately improve health outcomes for our older population,” says Professor Center.

This research was supported by Australia’s National Health and Medical Research Council, Osteoporosis Australia, the Bupa Health Foundation and the Mrs Gibson and Ernst Heine Family Foundation.

Professor Jacqueline Center is a conjoint professor and Dr Dana Bliuc is a conjoint senior lecturer at St Vincent’s Clinical School, Faculty of Medicine and Health, UNSW Sydney.

Featured image: (L-R) Prof Jacqueline Center, Dr Dana Bliuc © GIMR

Reference: Bliuc, D., Tran, T., Adachi, J.D., Atkins, G.J., Berger, C., van den Bergh, J., Cappai, R., Eisman, J.A., van Geel, T., Geusens, P., Goltzman, D., Hanley, D.A., Josse, R., Kaiser, S., Kovacs, C.S., Langsetmo, L., Prior, J.C., Nguyen, T.V., Solomon, L.B., Stapledon, C., Center, J.R. and (2021), Cognitive decline is associated with an accelerated rate of bone loss and increased fracture risk in women: a prospective study from the Canadian Multicentre Osteoporosis Study. J Bone Miner Res. https://doi.org/10.1002/jbmr.4402

Provided by Garvan Institute of Medical Research

Longer Interval Between The First & Second Pfizer Vaccine Boosts Antibody Levels And ‘Helper’ T Cells (Medicine)

A new study carried out in collaboration with the University of Birmingham shows both short and long dosing schedules of the Pfizer COVID-19 vaccine generate strong antibody and T cell immune responses.

The study, led by the University of Oxford, in collaboration with the Universities of Birmingham, Newcastle, Liverpool, Sheffield, and supported by the UK Coronavirus Immunology Consortium, is one of the most comprehensive studies into the immune response generated by the Pfizer COVID-19 vaccine to date.

It found T cell levels are well-maintained and antibody levels are higher following a longer interval between the first and second dose of the Pfizer COVID-19 vaccine, despite a significant drop in antibody levels between doses. Importantly, worldwide studies are showing that both the short and long dosing schedules lead to strong real-world protection against COVID-19, emphasising the importance of having a second dose of the vaccine.

The Protective Immunity from T cells to COVID-19 in Health workers study (PITCH) examined how antibody and T cell levels change over time following either a ‘short’ (3–4 weeks, average of 24 days) or ‘long’ (6–14 weeks, average of 70 days) interval between the first and second dose of the Pfizer COVID-19 vaccine. Of the 503 healthcare workers recruited to the study, 223 (44%) had previously had COVID-19.

Key findings:

  • For the longer dosing interval, antibody levels fell noticeably between the first and second dose when tested in the lab. In particular, neutralising antibody levels against the Delta variant were poorly induced after a single dose, and not maintained during the interval before the second dose. T cells were well-maintained between the first and second dose.
  • Following two vaccine doses, neutralising antibody levels were twice as high after the longer dosing interval compared with the shorter dosing interval.
  • After two doses, overall T cell levels were 1.6 times lower after the long compared with the short dosing schedule.  However, after the longer dosing interval, a higher proportion of T cells present were ‘helper’ T cells, which are important for long-term immune memory and helping generate antibodies to prevent infection.
  • The longer dosing interval resulted in higher neutralising antibody levels, after the second dose, against the Delta variant and all other Variants of Concern tested.

Regardless of the dosing schedule, the study found levels of antibodies and T cells varied significantly from person to person, which may depend on genetics, underlying health conditions, and past exposure to COVID-19 and other viruses. This underlies the importance of everyone getting two doses of the COVID-19 vaccine to maximise their own protection, particularly against Variants of Concern. Follow up of this cohort 6 and 12 months after vaccination is needed to investigate longer term immune response, as well as whether it translates to lower or less severe infection rates.

The study results are being published as a pre-print on ‘Cell Press Sneak Peak’ and have therefore not yet been peer reviewed.

Vaccines Minister Nadhim Zahawi said: “The findings from this latest PITCH study are hugely significant not just for the UK but for the world, helping us better understand the mechanics behind our immune response to COVID-19 and the importance of getting both doses of the vaccine.
“As we raced to offer a vaccine to all adults, we took the JCVI’s advice to shorten the dosing interval from 12 to 8 weeks to help protect more people against the Delta variant. This latest study provides further evidence that this interval results in a strong immune response and supports our decision.
“I urge every adult to get both doses of the vaccine protect yourself and those around you and we are looking to offer millions of the most vulnerable a booster jab from September to ensure this protection is maintained.”

Professor Paul Moss, Principal Investigator of the UK Coronavirus Immunology Consortium and Professor of Haematology at the University of Birmingham, said: “This is an important study that reveals how changing the interval between doses of the COVID-19 vaccine has a significant effect on the immune response generated. It also demonstrates the benefit of a team science approach that brings researchers together to understand key questions on the immunology of COVID-19. The UK Coronavirus Immunology Consortium has been incredibly successful in fostering new partnerships like this.”

Alex Richter, Professor in Clinical Immunology at the University of Birmingham, said: “Real world data demonstrates the Pfizer COVID-19 vaccine is effective at reducing levels of serious disease, hospitalisation and death. There is benefit after one dose but two doses provides a much more robust response. Understanding the underlying immune response generated by different dosing schedules will help maximise future protection, tackle new Variants of Concern and prevent reinfections.”

Dr Rebecca Payne, study author from Newcastle University, said: “Our study is one of the most comprehensive assessments of the immune response to SARS-CoV-2 following two doses of the Pfizer vaccine. We found an interesting pattern in the levels of immune cells present. Our study provides reassuring evidence that both dosing schedules generate robust immune responses against SARS-CoV-2 after two doses. For the longer schedule, the antibody levels dropped off between first and second dose, which included the loss of any neutralising effect against the Delta variant. However, T cell responses were consistent, indicating they may contribute to important protection against SARS-CoV-2 during this time. After the second dose on the longer dosing schedule, antibody levels surpassed those seen at the same time point after a shorter dosing interval. Although T cell levels were comparatively lower, the profile of T cells present suggested more support of immune memory and antibody generation. We now need to carry out more follow up studies to understand the full clinical significance of our findings.”

Professor Susanna Dunachie, PITCH study lead from University of Oxford, said: “We know that the Pfizer COVID-19 vaccine is very effective at preventing serious disease, even after one dose, but we don’t yet understand what the exact immune response is that underlies this effect. Our study aimed to shine a light on the different type of immune cells involved to help us better understand the potential mechanisms of protection, particularly against new Variants of Concern. It is clear from our findings that to maximise your individual protection, it is very important to get two doses of the COVID vaccine when offered.

“This work is the result of a big team effort. The study would not have been possible without collaboration between the researchers across all five universities. It has allowed us to bring clinical cohorts together and conduct one of the most in-depth analyses of the immune response to a COVID-19 vaccine yet.”

This study formed part of the PITCH Study (Protective Immunity from T-cells in Halthcare workers), which was funded by the UK’s Department of Health and Social Care. A contribution was also made from the UK Coronavirus Immunology Consortium (funded by UK Research and Innovation and the National Institute for Health Research).

Reference: Payne et al. 2021. Sustained T cell immunity, protection and boosting using extended dosing intervals of BNT162b2 mRNA vaccine.

Provided by University of Birmingham

People With 5 Or More Symptoms in First Week Of Infection More Likely To Develop Long COVID (Medicine)

The presence of more than five symptoms of COVID-19 in the first week of infection is significantly associated with the development of long COVID, irrespective of age or gender, according to a new University of Birmingham-led review.

The review by the University of Birmingham-led the Therapies for Long COVID (TLC) Study Group, published today in the Journal of the Royal Society of Medicine, summarises current research on symptom prevalence, complications and management of long COVID. Pooled prevalence data in the review highlights the ten most common symptoms of long COVID. These are fatigue, shortness of breath, muscle pain, cough, headache, joint pain, chest pain, altered smell, diarrhoea and altered taste.

The researchers identified two main symptom clusters of long COVID: those comprising exclusively of fatigue, headache and upper respiratory complaints; and those with multi-system complaints including ongoing fever and gastroenterological symptoms.

Lead author Dr Olalekan Lee Aiyegbusi, Deputy Director at the University of Birmingham’s Centre for Patient Reported Outcomes Research (CPROR), said: “There is evidence that the impact of acute COVID-19 on patients, regardless of severity, extends beyond hospitalisation in the most severe cases, to ongoing impaired quality of life, mental health and employment issues. People living with long COVID generally feel abandoned and dismissed by healthcare providers and receive limited or conflicting advice. More than one-third of the patients in one of the studies included in the review reported they still felt ill or in a worse clinical condition at eight weeks than at the onset of COVID-19.”

Dr Shamil Haroon, Clinical Lecturer in Primary Care and co-Principal Investigator of the University of Birmingham NIHR/UKRI funded TLC Study, further commented: “Neither the biological or immunological mechanisms of long COVID, nor the rationale for why certain people are more susceptible to these effects, are yet clear, limiting development of therapies. It is essential we act quickly to address these issues.”

In a comparison with other coronaviruses, the researchers suggest that in the longer term, patients with long COVID may also experience a similar disease trajectory to that of patients who had SARS or MERS, pointing to analysis showing that six months after hospital discharge, approximately 25% of patients hospitalised with SARS and MERS had reduced lung function and exercise capacity.

TLC Study’s Co-Principal Investigator Melanie Calvert, Professor of Outcomes Methodology at the University of Birmingham and NIHR Senior Investigator, said: “The wide range of potential symptoms and complications patients with long COVID may experience highlights the need for a deeper understanding of the clinical course of the condition. There is an urgent need for better, more integrated care models to support and manage patients with long COVID to improve clinical outcomes.”

Reference: Aiyegbusi et al (2021). ‘Symptoms, complications and management of long COVID: a review’. Royal Society of Medicine. DOI: 10.1177/01410768211032850

Provided by University of Birmingham

Huge Jurassic Seabed Uncovered in Cotswolds Quarry (Paleontology)

One of the largest and most important finds of exquisitely preserved Jurassic echinoderms – spiny-skinned marine animals such as starfish and sea urchins – has been uncovered by a University of Birmingham Research Associate.

The site, at an undisclosed location in the Cotswolds, was discovered by Neville Hollingworth, an Honorary Research Associate at the University of Birmingham, and his wife, Sally Hollingworth. Sally and Neville, both non-professional paleontologists alerted the Natural History Museum to its possible importance.

The pair originally researched the site during lockdown and later gained permission to investigate from the landowners.

Sally said, ‘We were looking for new sites to explore once lockdown ended. We do this by scrolling through google maps around areas we know fossils have been found. The site we eventually discovered, a small quarry, seemed perfect.’

Neville added, ‘We thought we would find a few interesting specimens but never expected the site to be so special. As soon as we realised what we were dealing with, and the scientific importance of it, we contacted the Natural History Museum.’

Some 167 million years ago, the site would have been a warm, relatively shallow sea. It contains the remains of species such as echinoderms, a group of animals including starfish, brittle stars, feather stars (stalk-less crinoids), sea lilies (stalked crinoids), sea cucumbers and echinoids (sea urchins and sea potatoes or dollars).

Natural History Museum experts have been excavating the site. Senior Curator Dr Tim Ewin, says: “The exceptional preservation of so many individuals belonging to diverse echinoderm groups is exceptional and makes the site comparable to the best in the world.”

Dr Ewin, added: “It seems likely that a river was flowing into the sea nearby bringing in high levels of nutrients which attracted the large numbers of echinoderms we are finding.

“It then appears that the whole area was rapidly buried during an underwater mudslide. This is evidenced by the fact that we are finding some fossilised stalked and unstalked crinoids here in what we refer to as a ‘death pose’, where the animals have died trying to shield themselves by wrapping their arms around their bodies.”

This series of events led to almost an entire ecosystem being preserved in exceptional quality. Feather stars, sea lilies and starfish fossils are traditionally extremely rare as their multiplate skeletons quickly falls apart after death meaning only instant burial would allow them to be preserved whole.

The team believe they have unearthed three new species so far, a type of feather star, a brittle star and a sea cucumber. Many of the other species being unearthed at the site are already known to science, however, many were described over 100 years ago and based on incomplete or poorly prepared specimens. The new site will therefore provide vital new information to describe and contextualise these species which will lead to a better understanding of how these iconic groups evolved and diversified into the ecologically important organisms they are today.

So far the team has spent three days excavating the site and have collected approximately 100 slabs, which are now being prepared for future study and public engagement.

Mark Graham, Senior Fossil Preparator at the Museum, explains: “Many of the specimens we have excavated are trapped in large slabs of clay in groups. We now need to carefully explore these blocks to discover the most scientifically important specimens and prepare them for public display.

“We have collected enough material to keep us busy for quite some time but I am hopeful that once cleaned up these fossils will provide a huge amount of new information about how these creatures and their long-gone ecosystem functioned.’

The team hope to return to the site again in the near future and have already begun the process of identifying the potentially new species discovered.

Featured image: Neville and Sally Hollingworth (Credit: Trustees of the Natural History Museum)

Provided by University of Birmingham

Whats The Influence Of Neurons In The Amygdala On The Perception Of Pain? (Neuroscience)

A central role in processing emotions has been ascribed to the almond shaped amygdala arranged in pairs in the brains of mammals. The amygdala ‘evaluates’ emotional memories, coordinates the phenomena of fear and ultimately decides on flight or fight reactions when we are confronted with danger. In addition to fear, it also influences emotions such as anger and joy as well as sexual drive and reproduction. In conjunction with the working group of Wulf Haubensak from the Research Institute of Molecular Pathology (IMP) in Vienna, the working group led by Prof. Dr. Andreas Hess, Chair of Pharmacology and Toxicology at FAU, has been investigating the influence of certain neurons in the amygdala on the representation of pain in other regions of the brain. The study was recently published online in the journal Communications Biology .

Two types of neurons

‘We have been able to prove that the amygdala is not only responsible for coordinating fear, but is also responsible for processing pain,’ says Prof. Andreas Hess. The messenger substances of neurons in the central nucleus of the amygdala lead to systemic changes in various regions of the brain and ultimately even to measurable changes in behaviour.

Anatomically, the amygdala consists of various nuclei. Two types of neurons were identified in the lateral area of the central amygdala. One type of neuron produces the enzyme protein kinase C δ (PKC δ+), which is important for cell communication, the other produces the neurotransmitter somatostatin (SST+). ‘Both neuron populations have an antagonistic effect and influence many other regions of the brain,’ explains Isabel Wank from the working group led by Prof. Andreas Hess from the Chair of Pharmacology and Toxicology at FAU. To find out if both types of neurons influence other regions of the brain such as the thalamus, they have to be deliberately switched on and off. To do so, the researchers used the established method of optogenetics.  The DNA of mice was genetically modified in such as way that it produced light-sensitive proteins in the cells mentioned above. The function of these cells can then be influenced from the outside by exposure to light. Firstly, a fibre-optic light guide was implanted into the central amygdala of mice under anaesthetic. This then enabled the researchers to ‘activate’ the neurons with blue lasers. The neurons deactivated themselves automatically after a short period of time.

Decisive influence on processing pain

To produce images of the influence of the activated PKC and SST neurons on other regions of the brain, the researchers used non-invasive functional magnetic resonance imaging (fMRI). By using this technique, they were able to show which areas of the brain are modulated by both cell populations and to what extent this modulation affects the processing of moderate heat stimuli applied for a short time to the mouse’s hind paw. ‘Using these highly-sensitive methods yields a clear result, even with only a few animals,’ says Prof. Hess.

The results show that the activated PKC neurons of the amygdala cause other regions of the brain to process pain to a lesser extent. The modulation is carried out ‘bottom up’, from the old regions of the brain in evolutionary terms to the cortex. In contrast, the SST neurons tended to lead to stronger ‘processing’ of the pain top down from the cortex. As the researchers from Vienna were able to demonstrate, activating the neurons also leads to changes in behaviour in the animals in the experiment. Compared to wild-type mice, the mice with activated SST neurons had a tendency to pull their paws away more quickly from the heat source, whereas activated PKC neurons led to a slower reaction. The amygdala evidently has a decisive modulating influence on the processing of pain stimuli in the brain.

As yet, the results of this fundamental research cannot be directly transferred to humans. However, the use of functional magnetic resonance imaging seems very promising. ‘What we were able to demonstrate using fMRI in mice can be directly transferred to humans,’ says Prof. Hess. The role of damage to the amygdala could therefore be investigated using fMRI on patients in future.

Featured image credit: colourbox

Further information:

Wank, I., Pliota, P., Badurek, S. et al. Central amygdala circuitry modulates nociceptive processing through differential hierarchical interaction with affective network dynamics. Commun Biol 4, 732 (2021). Doi: https://doi.org/10.1038/s42003-021-02262-3

Provided by FAU

Fujitsu Helps To Clean Up Space With First-Of-Its-Kind Mission Optimiser (Astronomy)

Less than a year on from the UK Space Agency committing £1 million in funding to combat space debris, Fujitsu UK has successfully combined quantum-inspired computing and Artificial Intelligence to support the transformation of space debris removal.

Fujitsu’s prototype –created in collaboration with the University of Glasgow, Amazon Web Services and Astroscale UK – will improve mission planning so that a single spacecraft can efficiently select which pieces of space debris to remove in one mission, and at a much faster rate than is currently possible.

The removal of space debris is key to sustainability in space, reducing, or even preventing, the risk of obsolete spacecraft colliding with new and existing satellites.

What’s more, supporting debris removal missions with Fujitsu’s technology will help to reduce the risk of catastrophic collisions in orbit which could create thousands of other pieces of new debris, all of which pose a very real threat to working satellites in orbit.

By carefully deciding which debris is collected and when, the quantum-inspired offering, powered by Digital Annealer, optimises the mission plan to determine the minimum-fuel and minimum-time required to bring inoperable spacecrafts or satellites safely back to the disposal orbit. Finding the optimal route to collect the space debris will save significant time and cost during the mission planning phase, and also as a consequence will improve commercial viability.

With 2,350 non-working satellites currently in orbit, and more than 28,000 pieces of debris being tracked by Space Surveillance networks, this technology will help the UK to grow its market share in the space sector. It will also further support the UK Government’s commitment to a more sustainable future overall.

Dr Matteo Ceriotti, a Lecturer in Space Systems Engineering, and PhD student Giulia Viavattene, have been leading on the project for the University of Glasgow, said: “The University of Glasgow has been involved in this project from the very outset – developing the trajectory models needed to effectively remove space debris, as well as estimating the cost of the transfers.

“The University has a long history of expertise in space trajectory design and optimisation so we were keen to be at the forefront of any government-led initiatives to enhance the UK’s reputation in the space sector. With the help of Fujitsu, AWS and Astroscale UK, we’ve helped to overcome challenges in space debris removal to make future projects much more straight-forward.”

Ellen Devereux, Digital Annealer Consultant at Fujitsu UK & Ireland, said: “All Space Debris poses a potential collision risk to the operational systems many of us take for granted – from weather forecasting to telecommunications.

“With the UK Space Agency’s backing, along with Astroscale UK, AWS and the University of Glasgow, we’ve designed a solution to optimise the mission planning of a servicing craft before it is sent into space – meaning organisations like Astroscale UK can pick up more debris, more quickly than ever before.

“It not only makes the process much more cost effective for those organisations needing to transfer and dispose of debris, but utilises AI and quantum inspired computing too.

“What we’ve learned over the course of the last six months, is that this technology has huge implications for optimisation in space; not only when it comes to cleaning up debris, but also in-orbit servicing and more. Now we better understand its potential, we can’t wait to see the technology applied during a future mission.”  

Jacob Geer, Head of Space Surveillance and Tracking, UK Space Agency, said: “Monitoring hazardous space objects is vital for the protection of services we all rely on – from communications devices to satellite navigation. This project is one of the first examples of Quantum-inspired computing working with artificial intelligence to solve the problems space debris causes, but it’s unlikely to be the last. 

“The UK is committed to ensuring the sustainability of space, and Fujitsu, working with Astroscale UK, The University of Glasgow and AWS, have demonstrated the real-world significance of keeping space uncluttered, assuring its accessibility for future generations.”

Stephen Wokes, Engineering Director, Astroscale UK said: “Finding the optimal mission plan manually is time consuming and complex. Astroscale UK is leading a pioneering next step for the End-of-Life Services by Astroscale (ELSA) Programme to remove not just one piece of debris, but multiple debris objects with a single servicer satellite, known as ELSA-M, which presents a substantially more economical way of removing debris from orbit. By coming together with Fujitsu, AWS and University of Glasgow, we hope to optimise this task even further for future missions.”

The research has been carried out as part of the UK Space Agency grant “Advancing Research into Space Surveillance and Tracking” The project, which was developed over six months in accordance Government Digital Services guidelines, leverages both Artificial Neural Network (ANN)-based rapid trajectory design algorithms, developed by the University of Glasgow, alongside Fujitsu’s Digital Annealer and Quantum Inspired Optimisation Services to solve some of the main optimisation problems associated with ADR (Active Debris Removal) mission planning design.

Amazon Web Services, provided the Cloud and AI and ML tools and services to support the project. The Amazon Sagemaker toolset was used to rapidly develop the ANNs that accurately predict the costs of orbital transfers in a fraction of the time it would take to calculate them in full.  Astroscale UK, the world’s first commercial company to start a demonstration mission to remove debris from the lower Earth orbit, is providing the end-use case as a representative user of multi-target mission optimisation.

Fujitsu, who spearheaded the project, is one of just seven UK companies to be awarded a share of over £1 million from the UK Space Agency to help track debris in space. The UK Space Agency and Ministry of Defence have announced the next step in their joint initiative to enhance the UK’s awareness of events in space.

Provided by University of Glasgow

Astronomers May Have Detected Second White Dwarf Pulsar (Cosmology)

Using Public Data Release of Zwicky Transient Facility observations, Japanese astronomers found that ZTF J185139.81+171430.3 (hereafter ZTF18abnbzvx) shows a very short very short (12.37 min) period and large-amplitude (0.8 mag) coherent variations. The unique white dwarf pulsar ‘AR sco’ is the only known object that shows similar very short period, large-amplitude and coherent variations. Their study recently appeared in Arxiv.

ZTF18abnbzvx is a variable object which was first detected by the Zwicky Transient Facility (ZTF) project. The object was classified as a dwarf nova by the Automatic Learning for the Rapid Classification of Events (ALeRCE) Alert Broker. The object was listed as a candidate variable star (ZTF J185139.81+171430.3, hereafter ZTF J1851) having a range of 17.561–18.836 and a period of 0.0086 d ~ 12.37 min. Automatic period detections often give spurious periods (either close to 1 d, 0.5 d or very short ones) and such periods are not usually considered seriously.

Figure 1: Short-period variation in ZTF J185139.81+171430.3 = ZTF18abnbzvx. © Kato and Kojiguchi

Now, by using Public Data Release 6 of the Zwicky Transient Facility observations, Kato and Kojiguchi found that this object showed large-amplitude (0.6–1.0 mag) and very short period variations during a time-resolved run on 2019 June 12 (BJD 2458646; figure 1). They first confirmed that the period of the star is in agreement with previously estimated one. Later, they also confirmed that the variations recorded for BJD 2458675–2458746, the segment with multiple nightly observations, could be expressed by the same period. Finally, by using the entire data BJD 2458646–2458746, they obtained a period of 0.0085 days ~ 12.37 min. The resultant phased light curve (figure 2) shows that the variations are coherent.

Figure 2: ZTF r phase-folded light curve of ZTF J185139.81+171430.3 = ZTF18abnbzvx for the segment BJD 2458675–2458746. The epoch was chosen as BJD 2458737.3078 © Kato and Kojiguchi

Additionally, it has been shown that the variation arising from the orbital variation (such as a reflection variable) is very unlikely considering the large amplitude (0.8 mag) and the very short (12.37 min) period. The only known class of binaries with comparably short periods are AM Canum Venaticorum stars (AM CVn stars). No known AM CVn stars with similar periods show such large-amplitude orbital modulations. The small parallax of 0.325(119) mas also does not favor an underluminous binary.

“Stellar pulsations are also unlikely. The large amplitude requires radial pulsations, but there is no known class of radially pulsating variables with this short period.”

— they said

Finally, they proposed that this short period may reflect the spin period of the white dwarf. The famous white dwarf pulsar AR Sco, which is a 3.56-hr binary consisting of a white dwarf and an M5 star. The spin period of the white dwarf in AR Sco is 1.97 min and amplitudes of the pulses reach 0.5–1.0 mag in the optical.

Figure 3: Long-term light curve of ZTF J185139.81+171430.3 = ZTF18abnbzvx from ZTF observations © Kato and Kojiguchi

In contrast to AR Sco, orbital modulations are not apparent in ZTF J1851 (figure 3). There were possible outbursts with amplitudes of ∼2 mag such as on BJD 2458685 and on BJD 2459042. The reality of these possible outbursts requires confirmation since there were only a few observations during these events A quasi-simultaneous rise in g and r was recorded on BJD 2459042. The object returned to the normal brightness on the subsequent day. These “outbursts”, if present, should have been short-lived as in outbursts in intermediate polars.

“Although further observations are needed to see whether the short-period coherent variations in ZTF J1851 indeed arises from a spinning white dwarf, this object would be a good candidate for a white dwarf pulsar and should deserve attention.”

— they concluded

Reference: Taichi Kuto and Naoto Kojiguchi, “ZTF J185139.81+171430.3 = ZTF18abnbzvx: the second white dwarf pulsar?”, pp. 1-3, 2021.

Note for editors of other websites: To reuse this article fully or partially kindly give credit either to our author/editor S. Ayan or provide a link of our article

Scientists Test Whether Brain Region is A Key Locus Of Learning (Neuroscience)

Long thought of as a generic alarm system, the locus coeruleus may actually be a sophisticated regulator of learning and behavior, an MIT team posits

Small and seemingly specialized, the brain’s locus coeruleus (LC) region has been stereotyped for its outsized export of the arousal-stimulating neuromodulator norepinephrine. In a new paper and with a new grant from the National Institutes of Health, an MIT neuroscience lab is making the case that the LC is not just an alarm button but has a more nuanced and multifaceted impact on learning, behavior and mental health than it has been given credit for.

With inputs from more than 100 other brain regions and sophisticated control of where and when it sends out norepinephrine (NE), the LC’s tiny population of surprisingly diverse cells may represent an important regulator of learning from reward and punishment, and then applying that experience to optimize behavior, said Mriganka Sur, Newton Professor of Neuroscience in The Picower Institute for Learning and Memory and the Department of Brain and Cognitive Sciences at MIT.

“What was formerly considered a homogenous nucleus exerting global, uniform influence over its many diverse target regions, is now suggested to be a heterogeneous population of NE-releasing cells, potentially exhibiting both spatial and temporal modularity that govern its functions,” wrote Sur, postdoc Vincent Breton-Provencher and graduate student Gabrielle Drummond in a review article published last month in Frontiers in Neural Circuits.

The article presents copious emerging evidence from Sur’s group and many others, suggesting that that the LC may integrate sensory inputs and internal cognitive states from across the brain to precisely exert its NE-mediated influence to affect actions – by throttling NE to the motor cortex – and the processing of resulting feedback of reward or punishment – by throttling NE to the prefrontal cortex.

To investigate that hypothesis, the team has begun working with a $2.1 million, 5-year NIH grant awarded in April. In this study they are engaging mice in learning tasks where they are cued by tones of varying pitches and volumes. Over the course of training the mice will learn that when a tone is high pitched, pressing a lever will yield a reward and when the tone is low pitched, the correct response would be to not push lest it experience an unpleasant air puff. By varying the tone volume, the experimenters will vary the certainty the mice can feel that they heard the cue correctly.

The hypothesis (borne out by preliminary data) predicts that the NE will matter in multiple crucial ways, Sur said. When the mouse hears the cue tone, if the pitch is low the LC would send less NE via a cadre of neurons to the motor cortex, reflecting the animal’s belief that the lever should not be pushed because no reward will be forthcoming. Meanwhile the lower the volume, the less certainty the animal has in its decision. Conversely, a high tone of high volume would send more NE, reflecting the animal’s certainty that pushing the lever would produce a reward.

After the mouse has acted, the more surprising the feedback, the more NE it will produce and send via a distinct group to the prefrontal cortex, stimulating greater learning. So for instance, if the mouse hears a faint, high tone and gingerly presses the lever, the surprise of a resulting reward will stimulate a strong output of NE to instruct the prefrontal cortex because its expectations weren’t very high. Whenever a mouse guesses wrong and feels an air puff, that will stimulate the strongest NE release to the prefrontal cortex. After such dynamics, Sur’s team has observed consistent performance changes on the subsequent trial.

“This is a way by which norepinephrine can be thought of as an arousal signal, but it’s also, importantly, in the context of ongoing function a learning signal,” Sur said. “It is both an execution signal and a learning signal, for both of which we can describe the actual quantitative relationships.”

Not only will the team be measuring the activity of LC-NE neurons, they’ll also take them over using optogenetics (in which neurons can be controlled with light), so that they can silence or amplify LC-NE output to show how doing each affects action and learning.

Understanding the true nature of how the LC works could be useful for improving treatments for certain disorders, Sur said. A potential treatment for PTSD, for instance, involves damping receptiveness to NE, but that also promotes drowsiness. A more principled and precise treatment could improve efficacy and reduce those side effects, he said.

“The hope is to affect the anxiety but not make you sleepy, if we understand the targets and theory behind it,” Sur said. “That is the hope of basic science for treating disorders—to make things more and more specific, to define the circuits and the specificity of functions that a system is involved in.”

Moreover the LC is an early region affected in Alzheimer’s disease, he said. Addressing that loss in the right way could help sustain forms of learning and cognition.

The study, “Locus Coeruleus Norepinephrine in Learned Behavior: Anatomical Modularity and Spatiotemporal Integration in Targets”, Front. Neural Circuits, 07 June 2021 | https://doi.org/10.3389/fncir.2021.638007

Featured image: The Locus Coeruleus is deep in the brain but projects circuits throughout the organ. © Sur Lab/ MIT Picower Institute

Provided by Picower Institute