Hexabundles: imaging fiber arrays for low-light astronomical applications

We demonstrate a novel imaging fiber bundle ("hexabundle") that is suitable for low-light applications in astronomy. The most successful survey instruments at optical-infrared wavelengths use hundreds to thousands of multimode fibers fed to one or more spectrographs. Since most celestial sources are spatially extended on the celestial sphere, a hexabundle provides spectroscopic information at many distinct locations across the source. We discuss two varieties of hexabundles: (i) lightly fused, closely packed, circular cores; (ii) heavily fused non-circular cores with higher fill fractions. In both cases, we find the important result that the cladding can be reduced to ~2 μm over the short fuse length, well below the conventional ~10λ thickness employed more generally, with a consequent gain in fill factor. Over the coming decade, it is to be expected that fiber-based instruments will be upgraded with hexabundles in order to increase the spatial multiplex capability by two or more orders of magnitude

Understanding how micro-organisms respond to acid pH is central to their control and successful exploitation

Microbes from the three domains of life, bacteria, archaea and eukarya, share the need to sense and respond to changes in the external and internal concentrations of protons. When the proton concentration is high, acidic conditions prevail and cells must respond appropriately to ensure that macromolecules and metabolic processes are sufficiently protected to sustain life. While we have learned much in recent decades about the mechanisms that microbes use to cope with acid, including the unique challenges presented by organic acids, there is still much to learn and much to be gained from developing a deeper understanding of the effects and responses to acid in microbes. In this perspective article, we survey the key molecular mechanisms that are known to be important for microbial survival during acid stress. We discuss the research approaches that have been taken to investigate the problem and highlight promising new avenues. We highlight the importance of understanding acid stress in controlling spoilage and pathogenic microbes in the food chain. We discuss the influence of acid on pathogens during the course of infections and highlight the potential of using organic acids in treatments for some types of infection. We explore the influence of acid stress on photosynthetic microbes, and on biotechnological and industrial processes, including those needed to produce organic acids. Finally, we invite colleagues with an interest in microbial responses to low pH to participate in the EU-funded COST Action project called EuroMicropH and contribute to a comprehensive database of literature on this topic that we are making publicly available

Conservation assessment and spatial distribution of endemic orchids in Sabah, Borneo

Orchids are among the most threatened plants due to habitat loss and illegal harvesting for horticultural demands. Sabah is a centre of orchid diversity, with approximately 1300 species of which 250 orchid taxa are endemic to Sabah. In this study, we conducted an IUCN Red List assessment on 136 endemic species and used Maximum Entropy (MaxEnt) to develop species distribution models for 47 species. The species distribution models were developed using presence-only data and six environmental predictors. The accuracy of the models were assessed using the area under the curve (AUC) and models with an AUC of higher than 0.8 stacked together to produce a species richness heatmap. We found that 83% of the researched species were threatened, of which 14 species were assessed to be Critically Endangered, eight species as Endangered and 93 species as Vulnerable. The heatmap shows that all of the species occurred within the Totally Protected Area (TPA) network in western Sabah. The heatmap highlighted the mid-altitude areas adjacent to the Kinabalu and Crocker Range parks and Ulu Sipitang regions as areas with a high species richness that were outside the TPA network. These areas are also important for the conservation of the majority of the species assessed as Critically Endangered and Endangered. Urgent conservation actions are needed to protect these species from extinction. The results from this work will be used as part of an intensive conservation action plan for threatened endemic orchids of Sabah and used to identify important plant areas currently not within the existing TPA networ

Maternal bonding styles in smokers and non-smokers: a comparative study

BACKGROUND: Parental bonding has been implicated in smoking behavior, and the quality of maternal bonding (MB) has been associated with poor mental health and substance use. However, little is known about the association of MB and the smoking of the offspring. METHODS: In our study, 129 smokers and 610 non-smoker medical students completed the parental bonding instrument, which measures MB along two dimensions: care and overprotection. Four categories can be created by high and low scores on care and overprotection: optimal parenting (OP; high care/low overprotection); affectionless control (ALC; low care/high overprotection); affectionate constraint (AC; high care/high overprotection), and neglectful parenting (NP; low care/low overprotection). Nicotine dependence was assessed by the Fagerstrom Nicotine Dependence Test, exhaled CO level, and daily cigarette consumption (CPD). RESULTS: Higher CPD was significantly associated with lower overprotection (p = 0.016) and higher care (p = 0.023) scores. The odds for being a smoker were significantly higher in the neglectful maternal bonding style compared to the other rearing styles (p = 0.022). Besides, smokers showed significantly higher care and lower overprotection scores with the Mann-Whitney U-test than non-smokers, although these associations did not remain significant in multiple regression models. CONCLUSION: Our results indicate that focusing on early life relationship between patient and mother can be important in psychotherapeutic interventions for smoking. Registration trials retrospectively registered

IFI27 transcription is an early predictor for COVID-19 outcomes, a multi-cohort observational study

PurposeRobust biomarkers that predict disease outcomes amongst COVID-19 patients are necessary for both patient triage and resource prioritisation. Numerous candidate biomarkers have been proposed for COVID-19. However, at present, there is no consensus on the best diagnostic approach to predict outcomes in infected patients. Moreover, it is not clear whether such tools would apply to other potentially pandemic pathogens and therefore of use as stockpile for future pandemic preparedness.MethodsWe conducted a multi-cohort observational study to investigate the biology and the prognostic role of interferon alpha-inducible protein 27 (IFI27) in COVID-19 patients.ResultsWe show that IFI27 is expressed in the respiratory tract of COVID-19 patients and elevated IFI27 expression in the lower respiratory tract is associated with the presence of a high viral load. We further demonstrate that the systemic host response, as measured by blood IFI27 expression, is associated with COVID-19 infection. For clinical outcome prediction (e.g., respiratory failure), IFI27 expression displays a high sensitivity (0.95) and specificity (0.83), outperforming other known predictors of COVID-19 outcomes. Furthermore, IFI27 is upregulated in the blood of infected patients in response to other respiratory viruses. For example, in the pandemic H1N1/09 influenza virus infection, IFI27-like genes were highly upregulated in the blood samples of severely infected patients.ConclusionThese data suggest that prognostic biomarkers targeting the family of IFI27 genes could potentially supplement conventional diagnostic tools in future virus pandemics, independent of whether such pandemics are caused by a coronavirus, an influenza virus or another as yet-to-be discovered respiratory virus

Non-reciprocity across scales in active mixtures

Acknowledgements: J.T. acknowledges the financial support of ANR Thema. A.D. acknowledges an international fellowship from Idex Universite de Paris. P.S. acknowledges support by a RSE Saltire Facilitation Network Award. Y.Z. acknowledges support from start-up grant NH10800621 from Soochow University.AbstractIn active matter, particles typically experience mediated interactions, which are not constrained by Newton’s third law and are therefore generically non-reciprocal. Non-reciprocity leads to a rich set of emerging behaviors that are hard to account for starting from the microscopic scale, due to the absence of a generic theoretical framework out of equilibrium. Here we consider bacterial mixtures that interact via mediated, non-reciprocal interactions (NRI) like quorum-sensing and chemotaxis. By explicitly relating microscopic and macroscopic dynamics, we show that, under conditions that we derive explicitly, non-reciprocity may fade upon coarse-graining, leading to large-scale equilibrium descriptions. In turn, this allows us to account quantitatively, and without fitting parameters, for the rich behaviors observed in microscopic simulations including phase separation, demixing, and multi-phase coexistence. We also derive the condition under which non-reciprocity survives coarse-graining, leading to a wealth of dynamical patterns. Again, our analytical approach allows us to predict the phase diagram of the system starting from its microscopic description. All in all, our work demonstrates that the fate of non-reciprocity across scales is a subtle and important question.</jats:p

Non-reciprocity across scales in active mixtures

Abstract In active matter, particles typically experience mediated interactions, which are not constrained by Newton’s third law and are therefore generically non-reciprocal. Non-reciprocity leads to a rich set of emerging behaviors that are hard to account for starting from the microscopic scale, due to the absence of a generic theoretical framework out of equilibrium. Here we consider bacterial mixtures that interact via mediated, non-reciprocal interactions (NRI) like quorum-sensing and chemotaxis. By explicitly relating microscopic and macroscopic dynamics, we show that, under conditions that we derive explicitly, non-reciprocity may fade upon coarse-graining, leading to large-scale equilibrium descriptions. In turn, this allows us to account quantitatively, and without fitting parameters, for the rich behaviors observed in microscopic simulations including phase separation, demixing, and multi-phase coexistence. We also derive the condition under which non-reciprocity survives coarse-graining, leading to a wealth of dynamical patterns. Again, our analytical approach allows us to predict the phase diagram of the system starting from its microscopic description. All in all, our work demonstrates that the fate of non-reciprocity across scales is a subtle and important question

Non-reciprocity across scales in active mixtures

Acknowledgements: J.T. acknowledges the financial support of ANR Thema. A.D. acknowledges an international fellowship from Idex Universite de Paris. P.S. acknowledges support by a RSE Saltire Facilitation Network Award. Y.Z. acknowledges support from start-up grant NH10800621 from Soochow University.In active matter, particles typically experience mediated interactions, which are not constrained by Newton’s third law and are therefore generically non-reciprocal. Non-reciprocity leads to a rich set of emerging behaviors that are hard to account for starting from the microscopic scale, due to the absence of a generic theoretical framework out of equilibrium. Here we consider bacterial mixtures that interact via mediated, non-reciprocal interactions (NRI) like quorum-sensing and chemotaxis. By explicitly relating microscopic and macroscopic dynamics, we show that, under conditions that we derive explicitly, non-reciprocity may fade upon coarse-graining, leading to large-scale equilibrium descriptions. In turn, this allows us to account quantitatively, and without fitting parameters, for the rich behaviors observed in microscopic simulations including phase separation, demixing, and multi-phase coexistence. We also derive the condition under which non-reciprocity survives coarse-graining, leading to a wealth of dynamical patterns. Again, our analytical approach allows us to predict the phase diagram of the system starting from its microscopic description. All in all, our work demonstrates that the fate of non-reciprocity across scales is a subtle and important question