Exploration Challenges: Transferring Ground Repair Techniques to Space Flight Application

Fulfilling NASA's Vision for Space Exploration will demand an extended presence in space at distances from our home planet that exceed our current experience in space logistics and maintenance. The ability to perform repairs in lieu of the customary Orbital Replacement Unit (ORU) process where a faulty part is replaced will be elevated from contingency to routine to sustain operations. The use and cost effectiveness of field repairs for ground based operations in industry and the military have advanced with the development of technology in new materials, new repair techniques and new equipment. The unique environments, accessibility constraints and Extra Vehicular Activity (EVA) issues of space operations will require extensive assessment and evolution of these technologies to provide an equivalent and expected level of assurance to mission success. Challenges include the necessity of changes in design philosophy and policy, extremes in thermal cycling, disruptive forces (such as static charge and wind entrainment) on developed methods for control of materials, dramatically increased volatility of chemicals for cleaning and other compounds due to extremely low pressures, the limits imposed on dexterity and maneuverability by current EVA equipment and practices, and the necessity of unique verification methodology. This paper describes these challenges in and discusses the effects on the established ground techniques for repair. The paper also describes the leading repair methodology candidates and their beneficial attributes for resolving these issues with the evolution of technology

Weighted-density approximation for general nonuniform fluid mixtures

In order to construct a general density-functional theory for nonuniform fluid mixtures, we propose an extension to multicomponent systems of the weighted-density approximation (WDA) of Curtin and Ashcroft [Phys. Rev. A 32, 2909 (1985)]. This extension corrects a deficiency in a similar extension proposed earlier by Denton and Ashcroft [Phys. Rev. A 42, 7312 (1990)], in that that functional cannot be applied to the multi-component nonuniform fluid systems with spatially varying composition, such as solid-fluid interfaces. As a test of the accuracy of our new functional, we apply it to the calculation of the freezing phase diagram of a binary hard-sphere fluid, and compare the results to simulation and the Denton-Ashcroft extension.Comment: 4 pages, 4 figures, to appear in Phys. Rev. E as Brief Repor

Mismatch repair causes the dynamic release of an essential DNA polymerase from the replication fork

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86887/1/MMI_7841_sm_SuppInfor.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/86887/2/j.1365-2958.2011.07841.x.pd

GPs’ understanding and practice of safety netting for potential cancer presentations : a qualitative study in primary care

Background Safety netting is a diagnostic strategy used in UK primary care to ensure patients are monitored until their symptoms or signs are explained. Despite being recommended in cancer diagnosis guidelines, little evidence exists about which components are effective and feasible in modern-day primary care. Aim To understand the reality of safety netting for cancer in contemporary primary care. Design and setting A qualitative study of GPs in Oxfordshire primary care. Method In-depth interviews with a purposive sample of 25 qualified GPs were undertaken. Interviews were recorded and transcribed verbatim, and analysed thematically using constant comparison. Results GPs revealed uncertainty about which aspects of clinical practice are considered safety netting. They use bespoke personal strategies, often developed from past mistakes, without knowledge of their colleagues’ practice. Safety netting varied according to the perceived risk of cancer, the perceived reliability of each patient to follow advice, GP working patterns, and time pressures. Increasing workload, short appointments, and a reluctance to overburden hospital systems or create unnecessary patient anxiety have together led to a strategy of selective active follow-up of patients perceived to be at higher risk of cancer or less able to act autonomously. This left patients with low-risk-but-not-no-risk symptoms of cancer with less robust or absent safety netting. Conclusion GPs would benefit from clearer guidance on which aspects of clinical practice contribute to effective safety netting for cancer. Practice systems that enable active follow-up of patients with low-risk-but-not-no-risk symptoms, which could represent malignancy, could reduce delays in cancer diagnosis without increasing GP workload

The Bolocam Galactic Plane Survey. XIV. Physical Properties of Massive Starless and Star Forming Clumps

We sort $4683$ molecular clouds between $10^\circ< \ell <65^\circ$ from the Bolocam Galactic Plane Survey based on observational diagnostics of star formation activity: compact $70$ $\mu{\rm m}$ sources, mid-IR color-selected YSOs, ${\rm H_2O}$ and ${\rm CH_3OH}$ masers, and UCHII regions. We also present a combined ${\rm NH_3}$-derived gas kinetic temperature and ${\rm H_2O}$ maser catalog for $1788$ clumps from our own GBT 100m observations and from the literature. We identify a subsample of $2223$ ($47.5\%$) starless clump candidates, the largest and most robust sample identified from a blind survey to date. Distributions of flux density, flux concentration, solid angle, kinetic temperature, column density, radius, and mass show strong ($>1$ dex) progressions when sorted by star formation indicator. The median starless clump candidate is marginally sub-virial ($\alpha \sim 0.7$) with $>75\%$ of clumps with known distance being gravitationally bound ($\alpha < 2$). These samples show a statistically significant increase in the median clump mass of $\Delta M \sim 170-370$ M$_\odot$ from the starless candidates to clumps associated with protostars. This trend could be due to (i) mass growth of the clumps at $\dot{M}\sim200-440$ Msun Myr$^{-1}$ for an average free-fall $0.8$ Myr time-scale, (ii) a systematic factor of two increase in dust opacity from starless to protostellar phases, (iii) and/or a variation in the ratio of starless to protostellar clump lifetime that scales as $\sim M^{-0.4}$. By comparing to the observed number of ${\rm CH_3OH}$ maser containing clumps we estimate the phase-lifetime of massive ($M>10^3$ M$_\odot$) starless clumps to be $0.37 \pm 0.08 \ {\rm Myr} \ (M/10^3 \ {\rm M}_\odot)^{-1}$; the majority ($M<450$ M$_\odot$) have phase-lifetimes longer than their average free-fall time.Comment: Accepted for publication in ApJ; 33 pages; 22 figures; 7 table

Outcomes from a single-intervention trial to improve interprofessional practice behaviors at a student-led free clinic

Background Interprofessional collaboration (IPC) is the practice of two or more healthcare professionals working together and learning from one another to improve health outcomes. IPC is important for quality training, typically improving individual and group level outcomes. Students value the opportunity for leadership and teamwork development when IPC is offered in their curriculum. The Indiana University Student Outreach Clinic (IUSOC) is a student run clinic that provides free primary care services to underserved residents residing in Indianapolis, Indiana. The IUSOC partner leaders identified a need to enhance knowledge about partner roles, scope of practice, and professional training with the hopes of improving quality of care through IPC and utilization of clinic resources. Methods A cluster randomized design consisted of education session days and control days. Participants had an equal selection probability. Student partners from ten different disciplines were involved. Two survey instruments were used for data collection: 1) The Interprofessional Socialization and Valuing Scale and 2) The Professional Consciousness Raising Questionnaire. The former measured the attitudes and beliefs that underlie interprofessional socialization, while the latter assessed pre/post student knowledge of the roles and responsibilities of each partner. Results The control arm of the study was composed of 167 student participants and the intervention arm had 170 participants. Participants in the intervention arm had greater scores for “ability to work with others”, “value in working with others”, and “comfort in working with others.” The intervention arm also had significantly increased odds of correctly identifying the roles responsibilities of the nursing, law, dental, and global health disciplines. Conclusions Results of this study demonstrate that administering a short interprofessional education exercise to healthcare professional students leads to improved IPC through increased interprofessional knowledge about other professions and change in beliefs and values toward the value of interprofessional collaboration among healthcare professionals

Insights into the Ecological Roles and Evolution of Methyl-Coenzyme M Reductase-Containing Hot Spring Archaea

Several recent studies have shown the presence of genes for the key enzyme associated with archaeal methane/alkane metabolism, methyl-coenzyme M reductase (Mcr), in metagenome-assembled genomes (MAGs) divergent to existing archaeal lineages. Here, we study the mcr-containing archaeal MAGs from several hot springs, which reveal further expansion in the diversity of archaeal organisms performing methane/alkane metabolism. Significantly, an MAG basal to organisms from the phylum Thaumarchaeota that contains mcr genes, but not those for ammonia oxidation or aerobic metabolism, is identified. Together, our phylogenetic analyses and ancestral state reconstructions suggest a mostly vertical evolution of mcrABG genes among methanogens and methanotrophs, along with frequent horizontal gene transfer of mcr genes between alkanotrophs. Analysis of all mcr-containing archaeal MAGs/genomes suggests a hydrothermal origin for these microorganisms based on optimal growth temperature predictions. These results also suggest methane/alkane oxidation or methanogenesis at high temperature likely existed in a common archaeal ancestor