Potential Microbial Processes In An Ancient Martian Environment, An Investigation Into Bio-Signature Production And Community Ecology

This work investigated whether the River Dee estuary can be considered as an martian environmental analogue and examined the whether an understanding of microbial processes could inform future life detection missions on Mars. The subsurface environment of the River Dee estuary, UK, and its microbial community, was characterised and compared to the palaeolake at Gale Crater, Mars. Similarities were identified in pH, temperature and Total Organic Carbon measurements, as well as potential bioessential element availability (based on comparative mineralogy of the two sites). The microbial community at the River Dee site was also characterised, indicating that a diverse bacterial community thrived there, alongside a single dominant archaeal group. This provided key insight into potential microbial communities on Mars, and associated processes that may inform future Mars research. Since the diversity and attributes of microorganisms is directly linked to their environment, the microbial community of the River Dee estuary was used to investigate potential martian geomicrobiological processes and community dynamics within a simulated martian experimental environment. Concentrations of the bioessential elements Fe, Mg and K were seen to increase in the biological experiments when compared with abiotic controls, leading to, for example, a 143 μmol L-1 difference in the concentration of Fe during the stationary phase. One bacterial group, the Acidobacteria Gp9, dominated the microbial community for 400 hr during the stationary phase, accounting for ~58 % of the microbial community at its peak. For a subsequent experiment, five bacterial species were isolated from the simulated martian environment, and characterised in order to demonstrate their growth optima and tolerance to relevant environmental extremes. Clostridium amygdalinum was found to be a model organism for survival within environments like the palaeolake at Gale Crater, and is proposed as a useful biological analogue for future investigations of the potential of life in such environments on Mars

The Microbial Community of a Terrestrial Anoxic Inter-Tidal Zone: A Model for Laboratory-Based Studies of Potentially Habitable Ancient Lacustrine Systems on Mars

Evidence indicates that Gale crater on Mars harboured a fluvio-lacustrine environment that was subjected to physio-chemical variations such as changes in redox conditions and evaporation with salinity changes, over time. Microbial communities from terrestrial environmental analogues sites are important for studying such potential habitability environments on early Mars, especially in laboratory-based simulation experiments. Traditionally, such studies have predominantly focused on microorganisms from extreme terrestrial environments. These are applicable to a range of Martian environments; however, they lack relevance to the lacustrine systems. In this study, we characterise an anoxic inter-tidal zone as a terrestrial analogue for the Gale crater lake system according to its chemical and physical properties, and its microbiological community. The sub-surface inter-tidal environment of the River Dee estuary, United Kingdom (53°21'015.40" N, 3°10'024.95" W) was selected and compared with available data from Early Hesperian-time Gale crater, and temperature, redox, and pH were similar. Compared to subsurface ‘groundwater’-type fluids invoked for the Gale subsurface, salinity was higher at the River Dee site, which are more comparable to increases in salinity that likely occurred as the Gale crater lake evolved. Similarities in clay abundance indicated similar access to, specifically, the bio-essential elements Mg, Fe and K. The River Dee microbial community consisted of taxa that were known to have members that could utilise chemolithoautotrophic and chemoorganoheterotrophic metabolism and such a mixed metabolic capability would potentially have been feasible on Mars. Microorganisms isolated from the site were able to grow under environment conditions that, based on mineralogical data, were similar to that of the Gale crater’s aqueous environment at Yellowknife Bay. Thus, the results from this study suggest that the microbial community from an anoxic inter-tidal zone is a plausible terrestrial analogue for studying habitability of fluvio-lacustrine systems on early Mars, using laboratory-based simulation experiments

Draft Genome Sequence of Clostridium sp. Strain E02, Isolated from an Estuarine Environment

Here, we report the draft genome sequence of a strain of Clostridium isolated from sediment collected from an estuarine environment. The strain was isolated using a minimal medium designed to select for chemoautotrophic microorganisms. The strain may represent a novel species within the genus Clostridium, and this genome sequence enables further investigation into the genetic and metabolic diversity of this organism

Achievement goals in adult learners: evidence from distance education

Background: There is evidence that learners may adopt different kinds of achievement goals: mastery approach, mastery avoidance, performance approach, and performance avoidance. In higher education, this evidence has mainly come from young people who have recently gone straight from secondary education to higher education. However, higher education is increasingly populated by older students, and it has been theorised that the relationship between goals and achievement might be very different for adult learners. Aims: The aim of the present study was to examine whether the relationships between achievement, drop‐out rate, and goal orientation observed for non‐adult populations are mirrored in adult learners. Method: The Achievement Goal Questionnaire (AGQ) was administered to adult learners taking courses by distance learning. Sample: Respondents were 195 men and 586 women between the ages of 19 and 87. Results: The results confirmed the reliability of the 2 × 2 version of the AGQ for this distinctive population. As in previous studies of younger students, mastery‐approach goals were unrelated to attainment, performance‐approach goals tended to facilitate attainment, and performance‐avoidance goals tended to impair attainment. In addition, mastery‐avoidance goals tended to impair students' attainment and also increased the likelihood that they would drop out of their course altogether. Conclusion: The achievement‐goal framework is as appropriate for understanding influences on attainment in adult learners as it is in younger students. Adult learners may be more sensitive to the deleterious effects of adopting mastery‐avoidance achievement goals

Doing cold smarter

Cold has been much neglected in the energy debate. Governments are developing strategies and policies to green everything from electricity to transport to heat, but the energy and environmental impacts of cooling have so far been largely ignored. This is a serious oversight, since making things cold is energy intensive and can be highly polluting, and demand for cooling in all its forms is booming worldwide – especially in developing countries. According to one projection, by the end of this century global demand for air conditioning alone could consume the equivalent of half our worldwide electricity generation today – and most of the increase will come in developing markets. The ‘greening’ of cold is clearly an urgent global problem – but it may also offer Britain a massive business opportunity. Cold may have been ignored but is vitally important to many aspects of modern life. An effective cold chain, for example, is essential for tackling problems such as food waste, food security, water conservation and public health. Cooling is also critical for many less obvious but essential functions: data centres couldn’t operate without it, nor for example MRI scanners in medicine or superconductors in power electronics. Cooling also provides modern levels of comfort in hot countries – and can make the difference between some regions being habitable or not. At the same time, vast amounts of cold are wasted – for instance during the regasification of LNG – which could in principle be recycled to satisfy some of this demand and start to reduce the environmental damage caused by cooling. Such a system-level approach – which starts by asking what energy services we need, and what is the least damaging way to provide them, rather than accepting existing practices as a fait accompli – has recently been coined the ‘Cold Economy’. It is clear the Cold Economy could unleash a wide range of innovative clean cold technologies and provide energy resilience, economic growth and environmental benefits, but there is an urgent need to develop a system-level analysis of this problem and the potential solutions to inform both industry and policymakers. The Birmingham Policy Commission: Doing Cold Smarter was convened to start this work

Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: a case study of Irish Sea beaches

In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the publicwho may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16 l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq 137Cs within large areas (10–20 km2 h−1), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15 m whilst maintaining speeds covering 1–2 km2 h−1 can detect buried 137Cs sources of 0.5 MBq or greater activity. A survey design to detect 100 kBq 137Cs sources at 10 cm depth has also been defined, requiring surveys at b15 m ground clearance and b2 m s−1 ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed

HIV prevention and HIV care among transgender and gender diverse youth: design and implementation of a multisite mixed-methods study protocol in the U.S.

Abstract Background In the U.S., transgender and gender diverse (TGD) populations face structural, interpersonal, and individual barriers to healthcare. Less is known, however, about the HIV prevention and treatment experiences of TGD youth in the U.S. The current study was developed to fill this research gap. Methods This article describes the research protocol for a multi-site, U.S.-based mixed-methods study that sought to identify the multi-level facilitators and barriers that influence participation of TGD youth in various stages of the HIV prevention (e.g., pre-exposure prophylaxis uptake) and care continua. A sample of diverse TGD youth ages 16–24 was recruited from 14 U.S. sites. TGD youth participants completed a one-time, in-person visit that included an informed consent process, computer-based quantitative survey, and in-depth qualitative interview assessing experiences accessing HIV prevention and/or care services. Providers serving TGD youth were recruited from the same 14 sites and completed a one-time visit via phone that included informed consent, demographic questionnaire, and in-depth qualitative interview assessing their experiences providing HIV prevention or treatment services to TGD youth. Results Overall, 186 TGD youth ages 16–24 and 59 providers serving TGD youth were recruited and enrolled from across the 14 U.S. sites. TGD youth participants had a mean age of 20.69; 77.3% youth of color; 59.7% trans-feminine; 15.5% trans-masculine; 24.9% non-binary; 53.6% family income under poverty level. Providers included medical and mental health providers as well as case manager/care coordinators, HIV test counselors, and health educators/outreach workers. Providers were 81.3% cisgender and 30.5% people of color. Successes with community-engagement strategies and gender-affirming research methods are reported. Conclusions This study addresses critical gaps in current knowledge about the HIV prevention and care experiences of TGD youth. Findings have implications for the development of HIV interventions across levels to support the health and well-being of TGD youth. Future research is warranted to replicate and expand on lessons learned regarding recruitment and engagement of communities of TGD youth, including longitudinal designs to assess engagement across their developmental stages. Lessons learned working with TGD youth through developing and implementing the study protocol are shared. Trial registration Registered on ClinicalTrials.gov on 05/20/2015 (NCT02449629).https://deepblue.lib.umich.edu/bitstream/2027.42/152132/1/12889_2019_Article_7605.pd

Multi-band ESCL transmission supported by bismuth-doped and Raman fiber amplification

Ultra-wideband transmission utilizes bandwidths beyond the standard C-band to enable significant network capacity upgrades. Upgrading the standard C-band to a C+L-band transmission scenario is already feasible, and exploratory transmission is being performed in the S-, E-, and O-bands to investigate quality of transmission (QoT) impairments in these spectral regions. In this paper, experimental transmission through a SCL- and partial E-band spectral region is performed, with use of a hybrid amplifier that exploits discrete Raman amplification for the SCL-bands, and a bismuth-doped fiber amplifier (BDFA) for the E-band. Through this transmission bandwidth, we demonstrate that 36 Tbit/s transmission is possible, with 150 coherent channels over 70 km of standard, single-mode fiber. This result is compared to a wideband physical layer model that considers a realistic full spectral load transmission scenario, where the E-band is occupied by 74 channels, providing a total of 221 channels. This comparison demonstrates that, for both scenarios in this experiment, the greatest impairment is present within the S-band, and the addition of the E-band to a SCL-band scenario has a negligible impact upon the QoT within the C- and L-bands