HFPK 334: An unusual Supernova Remnant in the Small Magellanic Cloud

We present new Australia Telescope Compact Array (ATCA) radio-continuum and XMM-Newton/Chandra X-ray Observatory (CXO) observations of the unusual supernova remnant HFPK 334 in the Small Magellanic Cloud (SMC). The remnant follows a shell type morphology in the radio-continuum and has a size of $\sim$20~pc at the SMC distance. The X-ray morphology is similar, however, we detect a prominent point source close to the center of the SNR exhibiting a spectrum with a best fit powerlaw with a photon index of $\Gamma = 2.7 \pm 0.5$. This central point source is most likely a background object and cannot be directly associated with the remnant. The high temperature, nonequilibrium conditions in the diffuse region suggest that this gas has been recently shocked and point toward a younger SNR with an age of $\lesssim 1800$ years. With an average radio spectral index of $\alpha=-0.59\pm0.09$ we find that an equipartition magnetic field for the remnant is $\sim$90~$\mu$G, a value typical of younger SNRs in low-density environments. Also, we report detection of scattered radio polarisation across the remnant at 20~cm, with a peak fractional polarisation level of 25$\pm$5\%.Comment: 19 pages, 6-figures, submitted to A

Dynamic characterization of an alkali-ion battery as a source for laser-cooled atoms

We investigate a solid-state, reversible, alkali-ion battery (AIB) capable of regulating the density of alkali atoms in a vacuum system used for the production of laser-cooled atoms. The cold-atom sample can be used with in-vacuum chronoamperometry as a diagnostic for the voltage-controlled electrochemical reaction that sources or sinks alkali atoms into the vapor. In a combined reaction-diffusion-limited regime, we show that the number of laser-cooled atoms in a magneto-optical trap can be increased both by initially loading the AIB from the vapor for longer, and by using higher voltages across the AIB when atoms are subsequently sourced back into the vapor. The time constants associated with the change in atom number in response to a change in AIB voltage are in the range of 0.5 s - 40 s. The AIB alkali reservoir is demonstrated to survive oxidization during atmospheric exposure, simplifying reservoir loading prior to vacuum implementation as a replacement for traditional resistively-heated dispensers. The AIB capabilities may provide an improved atom number stability in next-generation atomic clocks and sensors, while also facilitating fast loading and increased interrogation times.Comment: 7 pages, 5 figure

A magneto-optic trap using a reversible, solid-state alkali-metal source

We demonstrate a novel way to form and deplete a vapor-cell magneto-optic trap (MOT) using a reversible, solid-state alkali-metal source (AMS) via an applied polarized voltage. Using ~100 mW of electrical power, a trapped-atom number of 5x10^6 has been achieved starting from near zero and the timescales of the MOT formation and depletion of ~1 s. This fast, reversible, and low power alkali-atom source is desirable in both tabletop and portable cold-atom systems. The core technology of this device should translate readily to other alkali and alkaline-earth elements that could find a wide range of uses in cold-atom systems and instruments.Comment: 7 page

Luminescence from non-bioluminescent tissues in oceanic cephalopods

Several tissues (e.g. kidney, blood, digestive gland) in oceanic cephalopods which do not exhibit in vivo bioluminescence, luminesce when homogenized in the presence of air or when simply exposed to air in a vial (blood). The source of the luminescence appears to be a luciferin: treatment of kidney homogenates and blood with a photophore extract presumably containing luciferase resulted in a 20-fold increase in light production. Luminescence was also found in the renal fluid, which may be the source of luminescent clouds produced by squids. The variability in luminescence found in some tissues of cephalopods appeared to be related to feeding. Luminescence was also detected in the digestive glands of midwater octopods

Overcoming the Challenges Associated with Image-based Mapping of Small Bodies in Preparation for the OSIRIS-REx Mission to (101955) Bennu

The OSIRIS-REx Asteroid Sample Return Mission is the third mission in NASA's New Frontiers Program and is the first U.S. mission to return samples from an asteroid to Earth. The most important decision ahead of the OSIRIS-REx team is the selection of a prime sample-site on the surface of asteroid (101955) Bennu. Mission success hinges on identifying a site that is safe and has regolith that can readily be ingested by the spacecraft's sampling mechanism. To inform this mission-critical decision, the surface of Bennu is mapped using the OSIRIS-REx Camera Suite and the images are used to develop several foundational data products. Acquiring the necessary inputs to these data products requires observational strategies that are defined specifically to overcome the challenges associated with mapping a small irregular body. We present these strategies in the context of assessing candidate sample-sites at Bennu according to a framework of decisions regarding the relative safety, sampleability, and scientific value across the asteroid's surface. To create data products that aid these assessments, we describe the best practices developed by the OSIRIS-REx team for image-based mapping of irregular small bodies. We emphasize the importance of using 3D shape models and the ability to work in body-fixed rectangular coordinates when dealing with planetary surfaces that cannot be uniquely addressed by body-fixed latitude and longitude.Comment: 31 pages, 10 figures, 2 table

Comparative population structure of <i>Plasmodium malariae</i> and <i>Plasmodium falciparum</i> under different transmission settings in Malawi

&lt;b&gt;Background:&lt;/b&gt; Described here is the first population genetic study of Plasmodium malariae, the causative agent of quartan malaria. Although not as deadly as Plasmodium falciparum, P. malariae is more common than previously thought, and is frequently in sympatry and co-infection with P. falciparum, making its study increasingly important. This study compares the population parameters of the two species in two districts of Malawi with different malaria transmission patterns - one seasonal, one perennial - to explore the effects of transmission on population structures. &lt;BR/&gt; &lt;b&gt;Methods:&lt;/b&gt; Six species-specific microsatellite markers were used to analyse 257 P. malariae samples and 257 P. falciparum samples matched for age, gender and village of residence. Allele sizes were scored to within 2 bp for each locus and haplotypes were constructed from dominant alleles in multiple infections. Analysis of multiplicity of infection (MOI), population differentiation, clustering of haplotypes and linkage disequilibrium was performed for both species. Regression analyses were used to determine association of MOI measurements with clinical malaria parameters. &lt;BR/&gt; &lt;b&gt;Results:&lt;/b&gt; Multiple-genotype infections within each species were common in both districts, accounting for 86.0% of P. falciparum and 73.2% of P. malariae infections and did not differ significantly with transmission setting. Mean MOI of P. falciparum was increased under perennial transmission compared with seasonal (3.14 vs 2.59, p = 0.008) and was greater in children compared with adults. In contrast, P. malariae mean MOI was similar between transmission settings (2.12 vs 2.11) and there was no difference between children and adults. Population differentiation showed no significant differences between villages or districts for either species. There was no evidence of geographical clustering of haplotypes. Linkage disequilibrium amongst loci was found only for P. falciparum samples from the seasonal transmission setting. &lt;BR/&gt; &lt;b&gt;Conclusions:&lt;/b&gt; The extent of similarity between P. falciparum and P. malariae population structure described by the high level of multiple infection, the lack of significant population differentiation or haplotype clustering and lack of linkage disequilibrium is surprising given the differences in the biological features of these species that suggest a reduced potential for out-crossing and transmission in P. malariae. The absence of a rise in P. malariae MOI with increased transmission or a reduction in MOI with age could be explained by differences in the duration of infection or degree of immunity compared to P. falciparum

Gene expression during early ascidian metamorphosis requires signaling by Hemps, an EGF-like protein

Hemps, a novel epidermal growth factor (EGF)-like protein, is expressed during larval development and early metamorphosis in the ascidian Herdmania curvata and plays a direct role in triggering metamorphosis. In order to identify downstream genes in the Hemps pathway we used a gene expression profiling approach, in which we compared post-larvae undergoing normal metamorphosis with larval metamorphosis blocked with an anti-Hemps antibody. Molecular profiling revealed that there are dynamic changes in gene expression within the first 30 minutes of normal metamorphosis with a significant portion of the genome (approximately 49%) being activated or repressed. A more detailed analysis of the expression of 15 of these differentially expressed genes through embryogenesis, larval development and metamorphosis revealed that while there is a diversity of temporal expression patterns, a number of genes are transiently expressed during larval development and metamorphosis. These and other differentially expressed genes were localised to a range of specific cell and tissue types in Herdmania larvae and post-larvae. The expression of approximately 24% of the genes that were differentially expressed during early metamorphosis was affected in larvae treated with the anti-Hemps antibody. Knockdown of Hemps activity affected the expression of a range of genes within 30 minutes of induction, suggesting that the Hemps pathway directly regulates early response genes at metamorphosis. In most cases, it appears that the Hemps pathway contributes to the modulation of gene expression, rather than initial gene activation or repression. A total of 151 genes that displayed the greatest alterations in expression in response to anti-Hemps antibody were sequenced. These genes were implicated in a range of developmental and physiological roles, including innate immunity, signal transduction and in the regulation of gene transcription. These results suggest that there is significant gene activity during the very early stages of H. curvata metamorphosis and that the Hemps pathway plays a key role in regulating the expression of many of these genes

'In the wake of a pandemic': dietary patterns and impact on child health after COVID-19

INTRODUCTION Our companion Report: ‘Emerging Dietary Patterns: Impact on Child Health’ discussed ways in which traditional dietary patterns in both the UK and internationally were changing. In concluding we argued that: ‘The interconnected nature of food, climate and health is the biggest challenge we face, but therein also lies its strength and boundless potential should we act with the necessary urgency, creativity and commitment. It is at the local level – supported by national policy – that the largest returns from such pro-activity will accrue.’ We continued: ‘The food that we eat here and now can change the world.’ adding: ‘If we are serious about protecting and restoring natural environments, safeguarding the health and wellbeing of our children today and restoring and protecting that of future generations, then there is only one solution. We must change it.’ Then came Covid-19 and change was imposed – with the arrival and experience of a pandemic. The full outcome of Covid-19; its effects and repercussions not just for the present generations but for the many that will succeed it cannot be estimated now. In the 102 years since Spanish ‘flu devastated an older world order, we are still learning its lessons today. But what has become immediately apparent is that what we eat and how we eat has undergone a revolution in four short months. 6 ‘Coronavirus pandemic will change the food industry and eating habits forever, says CEO of Food and Drink Federation, Ian Wright.’ ([email protected] 7 April 2020) ‘To prevent the next pandemic we must take on factory farming.’ (Jonathan Safran Foer and Aaron Gross, The Guardian, 21 April 2020.) ‘Covid-19 will definitely be an accelerator on the conscious consumer patterns that we see unfolding. As the consumer gets more conscious, we also see more interest in sustainable, locally produced food systems solutions.’ (David Brandes, Food Navigator, 17 April 2020.) ‘The virus is a warning that Britain’s food system must change,’ (‘The Guardian,’ 18th April 2020). It would also be unjust to address the Covid-19 pandemic in isolation without highlighting its interactions with another global force to become manifest in the same era in response to an incident in the US; namely, the police killing of George Floyd and the Black Lives Matter Movement. Pandemics, poor health, systemic inequalities and a lack of environmental protections harm black, ethnic minority and disadvantaged communities in all countries more than any other groups, and the two events have shed a harsh light on those realities and their frightening interconnections – such as the higher death rate in BAME communities including healthcare workers on the frontline (Public Health England, June 2020, ‘Beyond the data: Understanding the impact of COVID-19 on BAME groups’): https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/892376/COVID_stakeholder_engagement_synthesis_beyond_the_data.pdf Therefore, to address fall-out from the pandemic without considering these marginalised groups would be inappropriate; to address the environmental crisis without considering its impact on such groups would be pointless and the separation of civil rights from health and environmental policy is delusional. The silos in which policy-making still exists in these fields are stubborn obstacles to change. Both within and without the UK’s boundaries, the diverse spectrum of peoples requires a similar diversity and inclusion in the systems that sustain life – and the production of the food that is eaten in order to live. Sometimes change is immediate and imposed rather than incremental and the pandemic has seen an abrupt conclusion to familiar and traditional ways of living. As we offer our thoughts about the many ways in which Covid-19 has changed our dietary patterns, we must remember that the ‘brave new world’ of our future ambition ‘has such people in it’, (‘The Tempest’, William Shakespeare). Those who would construct better dietary patterns in the wake of this pandemic must ensure that people rather than systems prevail…

Rationing tests for drug-resistant tuberculosis - who are we prepared to miss?

BACKGROUND: Early identification of patients with drug-resistant tuberculosis (DR-TB) increases the likelihood of treatment success and interrupts transmission. Resource-constrained settings use risk profiling to ration the use of drug susceptibility testing (DST). Nevertheless, no studies have yet quantified how many patients with DR-TB this strategy will miss. METHODS: A total of 1,545 subjects, who presented to Lima health centres with possible TB symptoms, completed a clinic-epidemiological questionnaire and provided sputum samples for TB culture and DST. The proportion of drug resistance in this population was calculated and the data was analysed to demonstrate the effect of rationing tests to patients with multidrug-resistant TB (MDR-TB) risk factors on the number of tests needed and corresponding proportion of missed patients with DR-TB. RESULTS: Overall, 147/1,545 (9.5%) subjects had culture-positive TB, of which 32 (21.8%) had DR-TB (MDR, 13.6%; isoniazid mono-resistant, 7.5%; rifampicin mono-resistant, 0.7%). A total of 553 subjects (35.8%) reported one or more MDR-TB risk factors; of these, 506 (91.5%; 95% CI, 88.9-93.7%) did not have TB, 32/553 (5.8%; 95% CI, 3.4-8.1%) had drug-susceptible TB, and only 15/553 (2.7%; 95% CI, 1.5-4.4%) had DR-TB. Rationing DST to those with an MDR-TB risk factor would have missed more than half of the DR-TB population (17/32, 53.2%; 95% CI, 34.7-70.9). CONCLUSIONS: Rationing DST based on known MDR-TB risk factors misses an unacceptable proportion of patients with drug-resistance in settings with ongoing DR-TB transmission. Investment in diagnostic services to allow universal DST for people with presumptive TB should be a high priority

Coupling models of cattle and farms with models of badgers for predicting the dynamics of bovine tuberculosis (TB)

Bovine TB is a major problem for the agricultural industry in several countries. TB can be contracted and spread by species other than cattle and this can cause a problem for disease control. In the UK and Ireland, badgers are a recognised reservoir of infection and there has been substantial discussion about potential control strategies. We present a coupling of individual based models of bovine TB in badgers and cattle, which aims to capture the key details of the natural history of the disease and of both species at approximately county scale. The model is spatially explicit it follows a very large number of cattle and badgers on a different grid size for each species and includes also winter housing. We show that the model can replicate the reported dynamics of both cattle and badger populations as well as the increasing prevalence of the disease in cattle. Parameter space used as input in simulations was swept out using Latin hypercube sampling and sensitivity analysis to model outputs was conducted using mixed effect models. By exploring a large and computationally intensive parameter space we show that of the available control strategies it is the frequency of TB testing and whether or not winter housing is practised that have the most significant effects on the number of infected cattle, with the effect of winter housing becoming stronger as farm size increases. Whether badgers were culled or not explained about 5%, while the accuracy of the test employed to detect infected cattle explained less than 3% of the variance in the number of infected cattle