Affordable Exploration of Mars: Recommendations from a Community Workshop

There is a growing opinion that within two decades initial human missions to Mars are affordable under plausible budget scenarios, with sustained international participation, and --- especially --- without requiring those first missions to achieve a burdensome number of goals. In response to this view, a group of experts from the Mars exploration stakeholder communities attended the "Affording Mars" workshop at George Washington University in December 2013. Participants reviewed scenarios for proposed affordable and sustainable human and robotic exploration of Mars, the role of the International Space Station as the essential early step toward humans to Mars, possible "bridge" or "transition" missions in the 2020s, key capabilities required for affordable initial missions, international partnerships, and usable definitions of affordability and sustainability. We report here the findings, observations, and recommendations that were agreed to at that workshop. In the context of affordable early missions to Mars, we also discuss the recent report of the National Research Council on human space flight and a pair of recent scenarios that appear to promise reduced costs

An orthogonal C-H borylation - cross-coupling strategy for the preparation of tetrasubstituted "A(2)B(2)''-chrysene derivatives with tuneable photophysical properties

Cl-substituents serve as a functionalisable regiocontrol element for the orthogonal functionalisation of chrysene.</p

Simulation study for analysis of binary responses in the presence of extreme case problems

<p>Abstract</p> <p>Background</p> <p>Estimates of variance components for binary responses in presence of extreme case problems tend to be biased due to an under-identified likelihood. The bias persists even when a normal prior is used for the fixed effects.</p> <p>Methods</p> <p>A simulation study was carried out to investigate methods for the analysis of binary responses with extreme case problems. A linear mixed model that included a fixed effect and random effects of sire and residual on the liability scale was used to generate binary data. Five simulation scenarios were conducted based on varying percentages of extreme case problems, with true values of heritability equal to 0.07 and 0.17. Five replicates of each dataset were generated and analyzed with a generalized prior (<b>g-prior</b>) of varying weight.</p> <p>Results</p> <p>Point estimates of sire variance using a normal prior were severely biased when the percentage of extreme case problems was greater than 30%. Depending on the percentage of extreme case problems, the sire variance was overestimated when a normal prior was used by 36 to 102% and 25 to 105% for a heritability of 0.17 and 0.07, respectively. When a g-prior was used, the bias was reduced and even eliminated, depending on the percentage of extreme case problems and the weight assigned to the g-prior. The lowest Pearson correlations between true and estimated fixed effects were obtained when a normal prior was used. When a 15% g-prior was used instead of a normal prior with a heritability equal to 0.17, Pearson correlations between true and fixed effects increased by 11, 20, 23, 27, and 60% for 5, 10, 20, 30 and 75% of extreme case problems, respectively. Conversely, Pearson correlations between true and estimated fixed effects were similar, within datasets of varying percentages of extreme case problems, when a 5, 10, or 15% g-prior was included. Therefore this indicates that a model with a g-prior provides a more adequate estimation of fixed effects.</p> <p>Conclusions</p> <p>The results suggest that when analyzing binary data with extreme case problems, bias in the estimation of variance components could be eliminated, or at least significantly reduced by using a g-prior.</p

A Bayesian Nonparametric Approach to Modeling Motion Patterns

The most difficult—and often most essential— aspect of many interception and tracking tasks is constructing motion models of the targets to be found. Experts can often provide only partial information, and fitting parameters for complex motion patterns can require large amounts of training data. Specifying how to parameterize complex motion patterns is in itself a difficult task. In contrast, nonparametric models are very flexible and generalize well with relatively little training data. We propose modeling target motion patterns as a mixture of Gaussian processes (GP) with a Dirichlet process (DP) prior over mixture weights. The GP provides a flexible representation for each individual motion pattern, while the DP assigns observed trajectories to particular motion patterns. Both automatically adjust the complexity of the motion model based on the available data. Our approach outperforms several parametric models on a helicopter-based car-tracking task on data collected from the greater Boston area

Cryogenics free production of hyperpolarized 129Xe and 83Kr for biomedical MRI applications

As an alternative to cryogenic gas handling, hyperpolarized (hp) gas mixtures were extracted directly from the spin exchange optical pumping (SEOP) process through expansion followed by compression to ambient pressure for biomedical MRI applications. The omission of cryogenic gas separation generally requires the usage of high xenon or krypton concentrations at low SEOP gas pressures to generate hp 129Xe or hp 83Kr with sufficient MR signal intensity for imaging applications. Two different extraction schemes for the hp gasses were explored with focus on the preservation of the nuclear spin polarization. It was found that an extraction scheme based on an inflatable, pressure controlled balloon is sufficient for hp 129Xe handling, while 83Kr can efficiently be extracted through a single cycle piston pump. The extraction methods were tested for ex vivo MRI applications with excised rat lungs. Precise mixing of the hp gases with oxygen, which may be of interest for potential in vivo applications, was accomplished during the extraction process using a piston pump. The 83Kr bulk gas phase T1 relaxation in the mixtures containing more than approximately 1% O2 was found to be slower than that of 129Xe in corresponding mixtures. The experimental setup also facilitated 129Xe T1 relaxation measurements as a function of O2 concentration within excised lungs

A challenging response to a Lassa fever outbreak in a non endemic area of Sierra Leone in 2019 with export of cases to The Netherlands.

INTRODUCTION: On November 20, 2019, the Sierra Leone International Health Regulations (IHR) National Focal Point was notified of an exported case of Lassa fever in The Netherlands, by a Dutch doctor who previously practiced in a rural hospital in Sierra Leone. This report describes the extent of the outbreak, possible sources of infection, and the outbreak response measures taken. METHODS: Response measures implemented to control the outbreak included coordination across multiple countries and cities, outbreak investigation, active case finding, contact tracing and monitoring, laboratory investigation, and isolation and treatment of cases. RESULTS: We report a hospital-associated outbreak that resulted in 3 confirmed cases (health workers) and 2 probable cases (patients). The case fatality rate was 60%, whereas the secondary attack rate was 14%. Two cases involved exportations to The Netherlands. Failure to detect the index case and poor adherence to infection prevention and control (IPC) protocols contributed to disease spread. Pregnancy status and nonspecific signs and symptoms of the index case contributed to failure in early case detection. CONCLUSIONS: Rapid activation of national and subnational incident management systems resulted in rapid outbreak control. We recommend regular training for clinicians on surveillance and IPC protocols and strengthening in-country Lassa virus diagnostic capacity

A randomised controlled trial of a digital intervention (Renewed) to support symptom management, wellbeing and quality of life in cancer survivors

Background: Many cancer survivors following primary treatment have prolonged poor quality of life.Aim: To determine the effectiveness of a bespoke digital intervention to support cancer survivors.Design: Pragmatic parallel open randomised trial.Setting: UK general practices.Methods: People having finished primary treatment (&lt;= 10 years previously) for colo-rectal, breast or prostate cancers, with European-Organization-for-Research-and-Treatment-of-Cancer QLQ-C30 score &lt;85, were randomised by online software to: 1) detailed ‘generic’ digital NHS support (‘LiveWell’;n=906), 2) a bespoke complex digital intervention (‘Renewed’;n=903) addressing symptom management, physical activity, diet, weight loss, distress, or 3) ‘Renewed-with-support’ (n=903): ‘Renewed’ with additional brief email and telephone support. Results: Mixed linear regression provided estimates of the differences between each intervention group and generic advice: at 6 months (primary time point: n’s respectively 806;749;705) all groups improved, with no significant between-group differences for EORTC QLQ-C30, but global health improved more in both intervention groups. By 12 months there were: small improvements in EORTC QLQ-C30 for Renewed-with-support (versus generic advice: 1.42, 95% CIs 0.33-2.51); both groups improved global health (12 months: renewed: 3.06, 1.39-4.74; renewed-with-support: 2.78, 1.08-4.48), dyspnoea, constipation, and enablement, and lower NHS costs (generic advice £265: in comparison respectively £141 (153-128) and £77 (90-65) lower); and for Renewed-with-support improvement in several other symptom subscales. No harms were identified.Conclusion: Cancer survivors quality of life improved with detailed generic online support. Robustly developed bespoke digital support provides limited additional short term benefit, but additional longer term improvement in global healthenablement and symptom management, with substantially lower NHS costs.<br/

Measuring Five Dimensions of Religiosity Across Adolescence

This paper theorizes and tests a latent variable model of adolescent religiosity in which five dimensions of religiosity are interrelated: religious beliefs, religious exclusivity, external religiosity, private practice, and religious salience. Research often theorizes overlapping and independent influences of single items or dimensions of religiosity on outcomes such as adolescent sexual behavior, but rarely operationalizes the dimensions in a measurement model accounting for their associations with each other and across time. We use longitudinal structural equation modeling (SEM) with latent variables to analyze data from two waves of the National Study of Youth and Religion. We test our hypothesized measurement model as compared to four alternate measurement models and find that our proposed model maintains superior fit. We then discuss the associations between the five dimensions of religiosity we measure and how these change over time. Our findings suggest how future research might better operationalize multiple dimensions of religiosity in studies of the influence of religion in adolescence