Using Simulated Micrometeoroid Impacts to Understand the Progressive Space Weathering of the Surface of Mercury

The surfaces of airless bodies such as Mercury are continually modified by space weathering, which is driven by micrometeoroid impacts and solar wind irradiation. Space weathering alters the chemical composition, microstructure, and spectral properties of surface regolith. In lunar and ordinarychondritic style space weathering, these processes affect the reflectance properties by darkening (lowering of reflectance), reddening (increasing reflectance with increasing wavelength), and attenuation of characteristic absorption features. These optical changes are driven by the production of nanophase Febearing particles (npFe). While our understanding of these alteration processes has largely been based on data from the Moon and near-Earth S-type asteroids, the space weathering environment at Mercury is much more extreme. The surface of Mercury experiences a more intense solar wind flux and higher velocity micrometeoroid impacts than its planetary counterparts at 1 AU. Additionally, the composition of Mercurys surface varies significantly from that of the Moon. Most notably, a very low albedo unit has been identified on Mercurys surface, known as the low reflectance material (LRM). This unit is enriched with up to 4 wt.% carbon, likely in the form of graphite, over the local mean. In addition, the surface concentration of Fe across Mercurys surface is low (<2 wt.%) compared to the Moon. Our understanding of how these low-Fe and carbon phases are altered as a result of space weathering processes is limited. Since Fe plays a critical role in the development of space weathering features on other airless surfaces (e.g., npFe), its limited availability on Mercury may strongly affect the space weathering features in surface materials. In order to understand how space weathering affects the chemical, microstructural, and optical properties of the surface of Mercury, we can simulate these processes in the laboratory [7]. Here we used pulsed laser irradiation to simulate the short duration, high temperature events associated with micrometeoroid impacts. We used forsteritic olivine, likely present on the Mercurian surface, with varying FeO contents, each mixed with graphite, in our experiments. We then performed reflectance spectroscopy and electron microscopy to investigate the spectral, chemical, and microstructural changes in these samples

Medical Biochemistry Without Rote Memorization: Multi-Institution Implementation And Student Perceptions Of A Nationally Standardized Metabolic Map For Learning And Assessment

Despite the growing number of patients worldwide with metabolism-related chronic diseases, medical biochemistry education is commonly perceived as focusing on recall of facts irrelevant for patient care. The authors suggest that this focus on rote memorization of pathways creates excessive cognitive load that may interfere with learners’ development of an integrated understanding of metabolic regulation and dysregulation. This cognitive load can be minimized by providing appropriate references during learning and assessment. Biochemistry educators collaborated to develop a medically relevant Pathways of Human Metabolism map (MetMap) that is now being used at many medical schools as a nationally standardized resource during learning and assessments. To assess impact, students from three medical schools were surveyed about its benefits and disadvantages. Responses were obtained from 481 students (84%) and were examined using thematic analysis. Five main themes emerged as perceived benefits of using the MetMap: 1) aids visual and mental organization, 2) promotes deep learning and applied understanding, 3) decreases emphasis on memorization, 4) reduces anxiety on exams, and 5) aids recall. Perceived disadvantages were: 1) fear of under-preparation for licensing exams, 2) overwhelming nature of the map, and 3) reduced motivation for and time spent studying. Results affirm that students perceive use of the MetMap promotes focus on broader metabolic concepts and deep versus surface learning, supporting a shift in cognitive load toward desired goals. Although the long-term impact on learning needs to be further studied, the use of the MetMap represents a step toward open-reference exams that reflect “real world” practice

Non-pharmacological interventions for ADHD in school settings: an overarching synthesis of systematic reviews

OBJECTIVE: This overarching synthesis brings together the findings of four systematic reviews including 138 studies focused on non-pharmacological interventions for ADHD used in school settings. These reviews considered the effectiveness of school-based interventions for ADHD, attitudes toward and experience of school-based interventions for ADHD, and the experience of ADHD in school settings. METHOD: We developed novel methods to compare the findings across these reviews inductively and deductively. RESULTS: Key contextual issues that may influence the effectiveness and implementation of interventions include the relationships that pupils with ADHD have with their teachers and peers, the attributions individuals make about the etiology of ADHD, and stigma related to ADHD or intervention attendance. CONCLUSION: Although we found some positive effects for some outcomes and intervention categories, heterogeneity in effect size estimates and research evidence suggests a range of diverse contextual factors potentially moderate the implementation and effectiveness of school-based interventions for ADHD.National Institute for Health Research Health Technology Assessment (NIHR HTA) programNIHR Collaboration for Leadership in Applied HealthResearch and Care South West Peninsula (PenCLAHRC

A Coding System to Measure Elements of Shared Decision Making During Psychiatric Visits

Objective: Shared decision making is widely recognized to facilitate effective health care. The purpose of this study was to assess the applicability and usefulness of a scale to measure the presence and extent of shared decision making in clinical decisions in psychiatric practice. Methods: A coding scheme assessing shared decision making in general medical settings was adapted to mental health settings, and a manual for using the scheme was created. Trained raters used the adapted scale to analyze 170 audio-recordings of medication check-up visits with either psychiatrists or nurse practitioners. The scale assessed the level of shared decision making based on the presence of nine specific elements. Interrater reliability was examined, and the frequency with which elements of shared decision making were observed was documented. The association between visit length and extent of shared decision making was also examined. Results: Interrater reliability among three raters on a subset of 20 recordings ranged from 67% to 100% agreement for the presence of each of the nine elements of shared decision making and 100% for the agreement between provider and consumer on decisions made. Of the 170 sessions, 128 (75%) included a clinical decision. Just over half of the decisions (53%) met minimum criteria for shared decision making. Shared decision making was not related to visit length after the analysis controlled for the complexity of the decision. Conclusions: The rating scale appears to reliably assess shared decision making in psychiatric practice and could be helpful for future research, training, and implementation efforts

Measuring Shared Decision Making in Psychiatric Care

The official published article is available online at http://doi.org/10.1176/appi.ps.201100496.OBJECTIVE: Shared decision making is widely recognized to facilitate effective health care; tools are needed to measure the level of shared decision making in psychiatric practice. METHODS: A coding scheme assessing shared decision making in medical settings (1) was adapted, including creation of a manual. Trained raters analyzed 170 audio recordings of psychiatric medication check-up visits. RESULTS: Inter-rater reliability among three raters for a subset of 20 recordings ranged from 67% to 100% agreement for the presence of each of nine elements of shared decision making and 100% for the overall agreement between provider and consumer. Just over half of the decisions met minimum criteria for shared decision making. Shared decision making was not related to length of visit after controlling for complexity of decision. CONCLUSIONS: The shared decision making rating scale appears to reliably assess shared decision making in psychiatric practice and could be helpful for future research, training, and implementation efforts

Are the processes recommended by the NHMRC for improving Cardiac Rehabilitation (CR) for Aboriginal and Torres Strait Islander people being implemented?: an assessment of CR Services across Western Australia

Background: Cardiovascular disease is the major cause of premature death of Indigenous Australians, and despite evidence that cardiac rehabilitation (CR) and secondary prevention can reduce recurrent disease and deaths, CR uptake is suboptimal. The National Health and Medical Research Council (NHMRC) guidelines Strengthening Cardiac Rehabilitation and Secondary Prevention for Aboriginal and Torres Strait Islander peoples, published in 2005, provide checklists for services to assist them to reduce the service gap for Indigenous people. This study describes health professionals' awareness, implementation, and perspectives of barriers to implementation of these guidelines based on semi-structured interviews conducted between November 2007 and June 2008 with health professionals involved in CR within mainstream health services in Western Australia (WA). Twenty-four health professionals from 17 services (10 rural, 7 metropolitan) listed in the WA Directory of CR services were interviewed.Results: The majority of respondents reported that they were unfamiliar with the NHMRC guidelines and as a consequence implementation of the recommendations was minimal and inconsistently applied. Respondents reported that they provided few in-patient CR-related services to Indigenous patients, services upon discharge were erratic, and they had few Indigenous-specific resources for patients. Issues relating to workforce, cultural competence, and service linkages emerged as having most impact on design and delivery of CR services for Indigenous people in WA.Conclusions: This study has demonstrated limited awareness and poor implementation in WA of the recommendations of the NHMRC Strengthening Cardiac Rehabilitation and Secondary Prevention for Aboriginal and Torres Strait Islander Peoples: A Guide for Health Professionals. The disproportionate burden of CVD morbidity and mortality among Indigenous Australians mandates urgent attention to this problem and alternative approaches to CR delivery. Dedicated resources and alternative approaches to CR delivery for Indigenous Australians are needed. © 2009 Thompson et al; licensee BioMed Central Ltd

Microglial activation decreases retention of the protease inhibitor saquinavir: implications for HIV treatment

Background Active HIV infection within the central nervous system (CNS) is confined primarily to microglia. The glial cell compartment acts as a viral reservoir behind the blood-brain barrier. It provides an additional roadblock to effective pharmacological treatment via expression of multiple drug efflux transporters, including P-glycoprotein. HIV/AIDS patients frequently suffer bacterial and viral co-infections, leading to deregulation of glial cell function and release of pro-inflammatory mediators including cytokines, chemokines, and nitric oxide. Methods To better define the role of inflammation in decreased HIV drug accumulation into CNS targets, accumulation of the antiretroviral saquinavir was examined in purified cultures of rodent microglia exposed to the prototypical inflammatory mediator lipopolysaccharide (LPS). Results [3H]-Saquinavir accumulation by microglia was rapid, and was increased up to two-fold in the presence of the specific P-glycoprotein inhibitor, PSC833. After six or 24 hours of exposure to 10 ng/ml LPS, saquinavir accumulation was decreased by up to 45%. LPS did not directly inhibit saquinavir transport, and did not affect P-glycoprotein protein expression. LPS exposure did not alter RNA and/or protein expression of other transporters including multidrug resistance-associated protein 1 and several solute carrier uptake transporters. Conclusions The decrease in saquinavir accumulation in microglia following treatment with LPS is likely multi-factorial, since drug accumulation was attenuated by inhibitors of NF-κβ and the MEK1/2 pathway in the microglia cell line HAPI, and in primary microglia cultures from toll-like receptor 4 deficient mice. These data provide new pharmacological insights into why microglia act as a difficult-to-treat viral sanctuary site