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

Making progress: the role of cancer councils in Australia in indigenous cancer control

Background: Indigenous Australians have poorer outcomes from cancer for a variety of reasons including poorer participation in screening programs, later diagnosis, higher rates of cancer with poor prognosis and poorer uptake and completion of treatment. Cancer prevention and support for people with cancer is part of the core business of the State and Territory Cancer Councils. To support sharing of lessons learned, this paper reports an environmental scan undertaken in 2010 in cancer councils (CCs) nationwide that aimed to support Indigenous cancer control. Methods: The methods replicated the approach used in a 2006 environmental scan of Indigenous related activity in CCs. The Chief Executive Officer of each CC nominated individuals for interview. Interviews explored staffing, projects, programs and activities to progress cancer control issues for Indigenous Australians, through phone or face-to-face interviews. Reported initiatives were tabulated using predetermined categories of activity and summaries were returned to interviewees, the Aboriginal and Torres Strait Islander Subcommittee and Chief Executive Officers for verification.Results: All CCs participated and modest increases in activity had occurred in most states since 2006 through different means. Indigenous staff numbers were low and no Indigenous person had yet been employed in smaller CCs; no CC had an Indigenous Board member and efforts at capacity building were often directed outside of the organisation. Developing partnerships with Indigenous organisations were ongoing. Acknowledgement and specific mention of Indigenous people in policy was increasing. Momentum increased following the establishment of a national subcommittee which increased the profile of Indigenous issues and provided collegial and practical support for those committed to reducing Indigenous cancer disparities. Government funding of “Closing the Gap” and research in the larger CCs have been other avenues for increasing knowledge and activity in Indigenous cancer control. Conclusions: This environmental scan measured progress, allowed sharing of information and provided critical assessment of progress across areas of importance for increasing Indigenous cancer control. Structured examination of policies, institutional support systems, programs and interventions is a useful means of highlighting opportunities for progress with minority groups relevant for many organisations. Progress has occurred with momentum likely to increase in the future and benefit from commitment to long-term monitoring and sharing of achievements

Prenatal and postnatal energetic conditions and sex steroids levels across the first year of life

Human biologists have documented variability in reproductive maturation, fertility, and cancer risk related to developmental conditions. Yet no previous studies have directly examined the impact of pre- and post-natal energetic environments on sex steroids in infancy, a critical period for hypothalamic-pituitary-gonadal axis development. Thus, we examined the impact of maternal characteristics, birth size, and feeding practices on fecal sex steroid production in a longitudinal sample of 31 American infants followed from 2 weeks to 12 months of age

Use of culturally focused theoretical frameworks for adapting diabetes prevention programs: A qualitative review

INTRODUCTION: Diabetes disproportionately affects underserved racial/ethnic groups in the United States. Diabetes prevention interventions positively influence health; however, further evaluation is necessary to determine what role culture plays in effective programming. We report on the status of research that examines cultural adaptations of diabetes prevention programs. METHODS: We conducted database searches in March and April 2014. We included studies that were conducted in the United States and that focused on diabetes prevention among African Americans, American Indians/Alaska Natives, Asian Americans/Pacific Islanders, and Latinos. RESULTS: A total of 58 studies were identified for review; 29 were excluded from evaluation. Few adaptations referenced or followed recommendations for cultural adaptation nor did they justify the content modifications by providing a rationale or evidence. Cultural elements unique to racial/ethnic populations were not assessed. CONCLUSION: Future cultural adaptations should use recommended processes to ensure that culture’s role in diabetes prevention–related behavioral changes contributes to research

Volunteer contributions in the emergency department: A scoping review

The objective of this scoping review was to identify published and unpublished reports that described volunteer programs in the emergency department (ED) and determine how these programs impacted patient experiences or outcomes. Electronic searches of Medline, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and CINAHL were conducted and reference lists were hand-searched. A grey literature search was also conducted. Two reviewers independently screened titles and abstracts, reviewed full text articles, and extracted data. The search strategy yielded 4,589 potentially relevant citations; 87 reports were included in the review. Volunteer activities were categorized as non-clinical tasks (e.g., provision of meals/snacks, comfort items and mobility assistance), navigation, emotional support/communication, and administrative duties. 52 (59.8%) programs had general volunteers in the ED and 35 (40.2%) had volunteers targeting a specific patient population, including pediatrics, geriatrics, patients with mental health and addiction issues and other vulnerable populations. 18 (20.6%) programs included an evaluative component describing how ED volunteers affected patient experiences and outcomes. Patient satisfaction, follow-up and referral rates, ED hospital costs and length of stay, subsequent ED visits, medical complications, and malnutrition in the hospital were all reported to be positively affected by volunteers in the ED. These findings demonstrate the important role volunteers play in enhancing patient and caregiver experience in the ED. Future volunteer engagement programs should be formally described and evaluated to share their success and experience with others interested in implementing similar programs in the ED. Experience Framework This article is associated with the Infrastructure & Governance lens of The Beryl Institute Experience Framework. (http://bit.ly/ExperienceFramework) Access other PXJ articles related to this lens. Access other resources related to this lens

E. coli Surface Properties Differ between Stream Water and Sediment Environments

The importance of E. coli as an indicator organism in fresh water has led to numerous studies focusing on cell properties and transport behavior. However, previous studies have been unable to assess if differences in E. coli cell surface properties and genomic variation are associated with different environmental habitats. In this study, we investigated the variation in characteristics of E. coli obtained from stream water and stream bottom sediments. Cell properties were measured for 77 genomically different E. coli strains (44 strains isolated from sediments and 33 strains isolated from water) under common stream conditions in the Upper Midwestern United States: pH 8.0, ionic strength 10 mM and 22∘C. Measured cell properties include hydrophobicity, zeta potential, net charge, total acidity, and extracellular polymeric substance (EPS) composition. Our results indicate that stream sediment E. coli had significantly greater hydrophobicity, greater EPS protein content and EPS sugar content, less negative net charge, and higher point of zero charge than stream water E. coli. A significant positive correlation was observed between hydrophobicity and EPS protein for stream sediment E. coli but not for stream water E. coli. Additionally, E. coli surviving in the same habitat tended to have significantly larger (GTG)5 genome similarity. After accounting for the intrinsic impact from the genome, environmental habitat was determined to be a factor influencing some cell surface properties, such as hydrophobicity. The diversity of cell properties and its resulting impact on particle interactions should be considered for environmental fate and transport modeling of aquatic indicator organisms such as E. coli

The longitudinal development of emotion regulation capacities in children at risk for externalizing disorders

The development of emotional regulation capacities in children at high versus low risk for externalizing disorder was examined in a longitudinal study investigating: a) whether disturbances in emotion regulation precede and predict the emergence of externalizing symptoms; and b) whether sensitive maternal behavior is a significant influence on the development of child emotion regulation. Families experiencing high (n=58) and low (n=63) levels of psychosocial adversity were recruited to the study during pregnancy. Direct observational assessments of child emotion regulation capacities and maternal sensitivity were completed in early infancy, at 12 and 18-months, and at 5-years. Key findings were as follows. First, high risk children showed poorer emotion regulation capacities than their low risk counterparts at every stage of assessment. Second, from 12-months onwards, emotion regulation capacities showed a degree of stability, and were associated with behavioral problems, both concurrently and prospectively. Third, maternal sensitivity was related to child emotion regulation capacities throughout development, with poorer emotion regulation in the high risk group being associated with lower maternal sensitivity. The results are consistent with a causal role for problems in the regulation of negative emotions in the etiology of externalizing psychopathology, and highlight insensitive parenting as a potentially key developmental influence

It's cool to be dominant : social status alters short-term risks of heat stress

Climate change has the potential to trigger social change. As a first step towards understanding mechanisms determining the vulnerability of animal societies to rising temperatures, we investigated interactions between social rank and thermoregulation in three arid-zone bird species: fawn-coloured lark (Mirafra africanoides, territorial); African red-eyed bulbul (Pycnonotus nigricans, loosely social) and sociable weaver (Philetairus socius, complex cooperative societies). We assessed relationships between body temperature (Tb), air temperature (Ta) and social rank in captive groups in the Kalahari Desert. Socially dominant weavers and bulbuls had lower mean Tb than subordinate conspecifics, and dominant individuals of all species maintained more stable Tb as Ta increased. Dominant bulbuls and larks tended to monopolise available shade, but dominant weavers did not. Nevertheless, dominantweavers thermoregulated more precisely, despite expending no more behavioural effort on thermoregulation than subordinates. Increasingly unequal risks associated with heat stress may have implications for the stability of animal societies in warmer climates.This study was supported by National Science Foundation Peer Grant no. PGA- 2000003431 to A.E.M., and funding from the DST-NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology to S.J.C. and M.L.T.http://jeb.biologists.org2018-05-30am2017Zoology and Entomolog