An Experimental Approach to Understanding the Optical Effects of Space Weathering

The creation and accumulation of nanophase iron (npFe(sup 0)) is the primary mechanism by which spectra of materials exposed to the space environment incur systematic changes referred to as "space weathering." The optical effects of this npFe(sup 0) on lunar soils are well documented. Space weathering though, should occur on the surface of any planetary body that is not protected by an atmosphere. There is no reason to assume that cumulative space weathering products throughout the solar system will be the same as those found in lunar soils. In fact, these products are likely to be very dependent on the specific environmental conditions under which they were produced. We have prepared a suite of analog soils to explore the optical effects of npFe(sup 0). By varying the size and concentration of npFe(sup 0) in the analogs we found significant systematic changes in the Vis/NIR spectral properties of the materials. Smaller npFe(sup 0) (40 nm in diameter) lowers the albedo across the Vis/NIR range with little change in the overall shape of the continuum. Intermediate npFe(sup 0) sizes impact the spectra in a distinct pattern that changes with concentration. The products of these controlled experiments have implications for space-weathered material throughout the inner solar system. Our results indicate that the lunar soil continuum is best modeled by npFe(sup 0) particles with bulk properties in the approx.15-25 nm size range. Larger npFe0 grains result in spectra that are similar in shape to the Mercury continuum. The continuum of S-type asteroid spectra appear to be best represented by small amounts of npFe(sup 0) that is similar to, but slightly smaller on average, than the npFe(sup 0) in lunar soils (approx.10-15 nm)

Kinneddar : A Major Ecclesiastical Centre of the Picts

The work at Kinneddar was conducted with kind permission from Pitgaveny Estates, organized by Duncan Dunbar-Nasmith. The fieldwork was made possible by funding from the Leverhulme Trust as part of the Comparative Kingship project (RL-2016-069), and Northern Picts funding through the University of Aberdeen Development Trust. Many thanks to Bruce Mann of Aberdeenshire Council Archaeology Service for advice and support.Peer reviewedPostprin

Lunar Dust Effects on Spacesuit Systems: Insights from the Apollo Spacesuits

Systems and components of selected Apollo A7L/A7LB flight-article spacesuits that were worn on the lunar surface have been studied to determine the degree to which they suffered contamination, abrasion and wear or loss of function due to effects from lunar soil particles. Filter materials from the lithium hydroxide (LiOH) canisters from the Apollo Command Module were also studied to determine the amount and type of any lunar dust particles they may have captured from the spacecraft atmosphere. The specific spacesuit study materials include the outermost soft fabric layers on Apollo 12 and 17 integrated thermal micrometeorite garment assemblies and outermost fabrics on Apollo 17 extravehicular pressure gloves. In addition, the degree of surface wear in the sealed wrist rotation bearing from Apollo 16 extravehicular and intravehicular pressure gloves was evaluated and compared. Scanning electron microscope examination of the Apollo 12 T-164 woven TeflonO fabric confirms the presence of lunar soil particles and the ability of these particles to cause separation and fraying of the Teflon fibers. Optical imaging, chemical analysis and particle sampling applied to the outer fabric of the Apollo 17 spacesuit has identified Ti as a potentially useful chemical marker for comparing the amount of lunar soil retained on different areas of the spacesuit outer fabric. High-yield particle sampling from the Apollo 17 fabric surfaces using adhesive tape found 80% of particles on the fabric are lunar soil particles averaging 10.5 m in diameter, with the rest being intrinsic fabric materials or environmental contaminants. Analysis of the mineralogical composition of the lunar particles found that on a grain-count basis the particle population is dominated by plagioclase feldspar and various types of glassy particles derived mostly from soil agglutinates, with a subordinate amount of pyroxene. On a grain size basis, however, the pyroxene grains are generally a factor of 2 larger than glass and plagioclase, so conversion of the data to a modal (volume %) basis results in pyroxene becoming the modally dominant particle type with glass and plagioclase significantly less abundant. When comparisons are made to the modal composition of lunar soil at the Apollo 17 landing site, the results suggest that pyroxene particles have overall better retention on the spacesuit outer fabric compared to plagioclase and especially glass. Scanning electron microscopy revealed no measureable difference in the amount of wear and abrasion in the wrist rotation bearing of an Apollo 16 pressure glove worn only in the spacecraft and one worn only for extravehicular activity on the lunar surface. The results suggest either that the bearing prevented entry of lunar dust, or that dust was not sufficiently abrasive to damage the bearing, or both

Implementing community-based participatory research among African Americans with serious and persistent mental illness: A qualitative study

Community-based participatory research (CBPR) is an approach that involves community members in research, not as research participants, but as partners. However, few studies have examined CBPR projects conducted among African Americans with serious and persistent mental illness (SPMI). This article focuses specifically on the Inspiring Change (IC) model, which includes a leadership trio comprised of an academic researcher, health service provider and an African American with lived experience of SPMI. Our purpose is to investigate how the IC model shapes not only how research is conducted but how research is understood and experienced by the community. We achieve this purpose by (1) describing an innovative CBPR model and pilot projects that involved African Americans with SPMI in all stages of the research project; and (2) presenting findings from qualitative interviews conducted with CBPR team members about strengths, challenges and leadership particular to this model of CBPR, an area rarely explored in CBPR literature. With the guidance of an advisory board and the manualised IC curriculum, two CBPR teams initiated and conducted nine-month long research projects focusing on health disparities for African Americans with SPMI. Members of the two CBPR teams (n = 13), which included individuals with lived experience, service providers and researchers, completed qualitative interviews. Benefits of CBPR projects included opportunities to learn, a sense of purpose in helping others and increased trust of research participants. Challenges pertained to disorganisation of leadership, lack of transparency with compensation, time pressures and interpersonal conflicts. These challenges highlight the importance of preparing and supporting those from both academic and lived experience backgrounds in skills necessary to thrive in leadership roles for CBPR projects. &nbsp

College Students’ Responses to Antismoking Messages: Denial, Defiance, and Other Boomerang Effects

Despite the success of antismoking campaigns that aim to prevent young teens from smoking, this qualitative study provides strong evidence that different initiatives are needed for college students, particularly those who already smoke. When asked for responses to current antismoking messages, nonsmokers generally championed the cause; however, smokers often responded with anger, defiance, denial, and other negative responses. Consumers who respond in this manner are not well served by existing strategies, and money used for such campaigns could be better spent. New strategies are offered in hopes that antismoking campaigns can communicate more effectively with one high-risk group—college student smokers

Fractal dimension (df) as a new structural biomarker of clot microstructure in different stages of lung cancer

Venous thromboembolism (VTE) is common in cancer patients, and is the second commonest cause of death associated with the disease. Patients with chronic inflammation, such as cancer, have been shown to have pathological clot structures with modulated mechanical properties. Fractal dimension (df) is a new technique which has been shown to act as a marker of the microstructure and mechanical properties of blood clots, and can be performed more readily than current methods such as scanning electron microscopy (SEM). We measured df in 87 consecutive patients with newly diagnosed lung cancer prior to treatment and 47 matched-controls. Mean group values were compared for all patients with lung cancer vs controls and for limited disease vs extensive disease. Results were compared with conventional markers of coagulation, fibrinolysis and SEM images. Significantly higher values of df were observed in lung cancer patients compared with controls and patients with extensive disease had higher values than those with limited disease (p< 0.05), whilst conventional markers failed to distinguish between these groups. The relationship between df of the incipient clot and mature clot microstructure was confirmed by SEM and computational modelling: higher df was associated with highly dense clots formed of smaller fibrin fibres in lung cancer patients compared to controls. This study demonstrates that df is a sensitive technique which quantifies the structure and mechanical properties of blood clots in patients with lung cancer. Our data suggests that df has the potential to identify patients with an abnormal clot micro-structure and greatest VTE risk

Clinical Outcome Scoring of Intra-articular Calcaneal Fractures

Outcome reporting of intra-articular calcaneal fractures is inconsistent. This study aimed to identify the most cited outcome scores in the literature and to analyze their reliability and validity. A systematic literature search identified 34 different outcome scores. The most cited outcome score was the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, followed by the Maryland Foot Score (MFS) and the Creighton-Nebraska score (CN). Reliability (internal consistency) and validity (content, construct, and criterion) were determined for the 3 outcome scoring systems. Internal consistency (Cronbach's alpha, reliability) was similar for the Maryland Foot Score (α = 0.82) and American Orthopedic Foot and Ankle Society hindfoot score (α = 0.78), but lower for the Creighton-Nebraska (α = 0.61). Floor and ceiling effects were good for all 3 scores. The individual items within these outcome scores showing best content validity were pain, return to work, subtalar range of motion, walking distance, ankle range of motion, and gait abnormalities or limping. Construct validity was good for all individual items except sagittal motion, stability at physical exam, and shoe size. The 3 outcome scores showed high correlation with patient satisfaction as measured with a visual analog scale (VAS, criterion validity) and indication for an arthrodesis. In conclusion, pending consensus, we would recommend choosing between the widely accepted, reliable and valid AOFAS hindfoot and the Maryland Foot Score as the scoring systems of choice. Level of Clinical Evidence: 2

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty