Optical properties of silicon carbide for astrophysical applications I. New laboratory infrared reflectance spectra and optical constants

Silicon Carbide (SiC) optical constants are fundamental inputs for radiative transfer models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties of the cubic (beta) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for beta- and alpha-SiC derived from single-crystal reflectance spectra and investigate quantitatively whether there is any difference between alpha- and beta-SiC that can be seen in infrared spectra and optical functions. Previous optical constants for SiC do not reflect the true bulk properties, and they are only valid for a narrow grain size range. The new optical constants presented here will allow narrow constraints to be placed on the grain size and shape distribution that dominate in astrophysical environments. In addition, our calculated absorption coefficients are much higher than laboratory measurements, which has an impact on the use of previous data to constrain abundances of these dust grains.Comment: 12 pages; 10 figures; laboratory optical constants available from CDS. Accepted by Astronomy & Astrophysic

The Effect of Posterior Foot Positions on Electromyography, Joint Kinetics and Energetics During a Sit-to-Stand in Young and Older Adults

The sit-to-stand (STS) movement, defined as standing up from a chair to an upright posture, is a common task performed daily. The inability to accomplish this task may lead to dependence, institutionalization and even death in older adults. A common strategy change for the STS is positioning the feet posteriorly by increasing flexion at the knee joint. This reduces the displacement of the center of mass to the base of support while increasing the joint moment of force at the knee while decreasing it at the hip. The aims of this study were to: 1) examine the joint kinetics, joint energetics and muscle activations of a STS task between young and older adults, and 2) determine the effects of posteriorly placing the feet on joint kinetics. joint energetics and muscle activations in STS. Twenty participants were recruited for this study. The samples consisted of 10 young participants (age: 22.3±2.06 yr; mass: 70.1±11.7 kg; height: 1.71±0.06 m), and 10 older participants (age: 72.7±5.96 yr; mass: 82.2±13.84 kg; height: 1.73±0.07 m). Both groups were recreationally active, free of lower extremity injury in the past six months and had no history surgery to the lower extremity. Participants were asked to complete five STS with a natural foot position and then with their feet placed 0.10m posterior to the initial position. Three-dimensional marker coordinate data were collected synchronously with three-dimensional force data and surface electromyography (EMG) of 8 lower extremity muscles. Results indicate that older adults have statistically higher integrated EMG activity in the soleus, rectus femoris and hamstrings muscles along with a statistically higher ankle joint angular impulse. Shifting the feet back produced statistically different values for trunk flexion, time of the rising phase, lower body joint work and hip joint angular impulse. The feet back condition also significantly decreased the integrated EMG magnitude for the tibailis Anterior, vastus lateralis and the hamstring muscles. This study reveals the benefits and limitations to a feet back condition for the STS. Placing the feet back will reduce the time of the rising phase while consequently reducing the magnitude of integrated EMG of the lower body muscles and decreasing the hip joint angular impulse. However, ankle joint angular impulse was increased in older adults with a foot back position. Specific attention should be provided to the individual when applying the feet back condition

...Make Them Disappear With A Piece of Paper : Understanding the Lived Realities of Federally Unrecognized Indigenous Women in the Southeast

Indigenous women experience some of the highest rates of violence and negative health outcomes of any racial/ethnic group yet are largely ignored in social science research. This dissertation explores the lived realities of Indigenous women who are members of federally unrecognized nations and how their tribal membership impacts their experiences with a variety of criminal justice and social issues. Unrecognized nations do not have access to potential benefits, opportunities, and legitimacy that comes with federal recognition thereby creating an additional intersection to consider for some Indigenous women. Essentially, federal recognition policies seek to place further constraints on Indigenous identity, while attempting to eliminate unrecognized nations from the U.S. population; the absence of recognition is therefore a form of social death that exacerbates many negative aspects of the Indigenous experience. This research explores the question: What are the lived realities of Indigenous women who are members of federally unrecognized nations, explicitly, their experiences with criminal victimization, the criminal legal system, homelessness, unemployment, racism, and other structural criminogenic conditions? To explore this research question, I used Tribal Critical Race Theory as the theoretical framework. In-depth semi-structured interviews center the stories of women who are members of federally unrecognized nations to understand the impact of the absence of federal recognition. As Indigenous women, they are more likely to experience violence in various forms, making it important that we consider all barriers they encounter to justice, including federal recognition. Using this framework and historical context, three themes emerged from 21 interviews with members of federally unrecognized nations: postcolonial distress, social death, and survivance and resilience. Postcolonial distress is a concept that refers to Indigenous people’s experiences of awareness of previous, historical events that were harmful to their ancestors and community, as well as exposure to current events and policies that are harmful. Narrators’ experiences with causes of postcolonial distress include experiences with familial conflicts, suicide, interpersonal violence, disproportionate contact with the criminal legal system, substance addiction, and sexual violence and sexual harassment. Social death refers to the experience of lacking legal rights to live as a citizen with self-determination. Persons in this category are exposed to systematic violence, degradation/humiliation, and natal alienation. Narrators described experiences with social death via systematic violence, humiliation, and natal alienation via religious and cultural erasure, bureaucratic erasure, and the delegitimization of their Indigenous identity. The theme of survivance refers to Indigenous people and their active presence in society, in spite of policies that seek to eliminate and harm Indigenous people and communities. Highlighting these stories are important for reminding society that Indigenous people do still exist. These experiences of survivance and resilience include their individual achievements and those of their relatives, their striving for and ability to maintain community, and their expression of religion and spirituality. The final chapter discusses positionality, policy implications, and directions for future research

Suicide Reporting Within British Newspapers' Arts Coverage Content Analysis of Adherence to Media Guidelines

Background: Many suicide prevention strategies promote media guidelines on suicide reporting, given evidence that irresponsible reporting of suicide can influence imitative suicidal behavior. Due to limited resources, monitoring of guideline adherence has tended to focus on news outputs, with a risk of neglecting other journalistic content. Aims: To determine whether British newspapers’ arts coverage adheres to media guidelines on suicide reporting. Method: Purposive sampling was used to capture current national practice on suicide reporting within newspapers’ arts coverage of exhibitions. Recent major UK exhibitions by artists who had died by suicide were identified: Kirchner, Rothko, Gorky, and Van Gogh. Content analysis of all UK national newspaper coverage of these exhibitions was performed to measure the articles’ adherence to widely accepted media guidelines. Results: In all, 68 newspaper reviews satisfied inclusion criteria, with 100% failing to show full adherence to media guidelines: 21% used inappropriate language; 38% provided explicit descriptions of the suicide; 7% employed simplistic explanations for suicide triggers; 27% romanticized the suicide; and 100% omitted information on sources of support. Conclusion: British newspapers’ arts coverage of exhibitions deviates considerably from media guidelines on the reporting of suicide. The findings suggest scope to improve journalists’ awareness of the importance of this component of suicide prevention strategies

Open versus blind peer review: is anonymity better than transparency?

Peer review is widely accepted as essential to ensuring scientific quality in academic journals, yet little training is provided in the specifics of how to conduct peer review. In this article we describe the different forms of peer review, with a particular focus on the differences between single-blind, double-blind and open peer review, and the advantages and disadvantages of each. These illustrate some of the challenges facing the community of authors, editors, reviewers and readers in relation to the process of peer review. We also describe other forms of peer review, such as post-publication review, transferable review and collaborative review, and encourage clinicians and academics at all training stages to engage in the practice of peer review as part of continuing professional development

Antarctic killer whales make rapid, round-trip movements to subtropical waters: evidence for physiological maintenance migrations?

Killer whales (Orcinus orca) are important predators in high latitudes, where their ecological impact is mediated through their movements. We used satellite telemetry to provide the first evidence of migration for killer whales, characterized by fast (more than 12 km h−1, 6.5 knots) and direct movements away from Antarctic waters by six of 12 type B killer whales tagged when foraging near the Antarctic Peninsula, including all tags transmitting for more than three weeks. Tags on five of these whales revealed consistent movements to subtropical waters (30–37° S) off Uruguay and Brazil, in surface water temperatures ranging from −1.9°C to 24.2°C; one 109 day track documented a non-stop round trip of almost 9400 km (5075 nmi) in just 42 days. Although whales travelled slower in the warmest waters, there was no obvious interruption in swim speed or direction to indicate calving or prolonged feeding. Furthermore, these movements were aseasonal, initiating over 80 days between February and April; one whale returned to within 40 km of the tagging site at the onset of the austral winter in June. We suggest that these movements may represent periodic maintenance migrations, with warmer waters allowing skin regeneration without the high cost of heat loss: a physiological constraint that may also affect other whales