Growth, strain, and spin-orbit torques in epitaxial Ni-Mn-Sb films sputtered on GaAs

We report current-induced spin torques in epitaxial NiMnSb films on a commercially available epiready GaAs substrate. The NiMnSb was grown by cosputtering from three targets using optimized parameters. The films were processed into microscale bars to perform current-induced spin-torque measurements. Magnetic dynamics were excited by microwave currents, and electric voltages along the bars were measured to analyze the symmetry of the current-induced torques. We found that the extracted symmetry of the spin torques matches those expected from spin-orbit interaction in a tetragonally distorted half-Heusler crystal. Both fieldlike and dampinglike torques are observed in all the samples characterized, and the efficiency of the current-induced torques is comparable to that of ferromagnetic metal/heavy-metal bilayers

Historical geography II: traces remain

The second report in this series turns to focus on the trace in relation to life-writing and biography in historical geography and beyond. Through attention to tracing journeys, located moments and listening to the presence of ghosts (Ogborn, 2005), this report seeks to highlight the range of different ways in which historical geographers have explored lives, deaths, and their transient traces through varied biographical terrains. Continuing to draw attention in historical geography to the darkest of histories, this piece will pivot on moments of discovering the dead to showcase the nuanced ways in which historical geography is opening doors into uncharted lives and unspoken histories

A bear’s biography: hybrid warfare and the more-than-human battlespace

This paper makes an intervention highlighting the animal dimension of military geographies as an overlooked yet illuminating aspect of the hybrid nature of warfare. By bringing animal geographies into dialogue with critical military geographies and with a focus on relational ethics, the processes, performance and consequences of the more-than-human nature of the battlespace are examined through a vignette of Wojtek the bear. Wojtek was a mascot, pet and officially enlisted soldier of the Polish Army in the Second World War who travelled the desert plains, helped to fight at the Battle of Monte Cassino, before being demobbed with his fellow Polish comrades in the UK, eventually ending his civilian days in Edinburgh Zoo. Although a well-known figure Wojtek and his biography have predominately been used as a means to explore the Polish soldiers’ experience of the Second World War with the result that the bear as an animal is absent. This paper, therefore, puts the bear back into his biography in order to acknowledge the role and lived experience of animals in the military. Further, it suggests that exploring the place of animals in the military requires geographers to articulate the hybrid nature of warfare and also to explore the ethico-political relations this produces

The Chemical Distribution in a Subluminous Type Ia Supernova: HST Images of the SN 1885 Remnant

We present HST images of the remnant of SN 1885 seen in absorption against M31's bulge via resonance lines of Ca I, Ca II, Fe I, and Fe II. Viewed in CaII H & K line absorption, the remnant appears as a nearly black circular spot with an outermost angular radius of 0.40" +/- 0.025" implying r = 1.52 pc and a 120 yr average expansion velocity of 12400 +/-1400 km/s. The strongest Ca II absorption is organized in a broken ring structure with a radius of 0.20" (=6000 km/s) with several apparent absorption `clumps' of an angular size near the pixel scale of 0.05" (= 1500 km/s). The detection of Ca II clumps is the first direct evidence for some instabilities and the existence of a deflagration phase in SNe Ia or, alternatively, mixing induced by radioactive decay of 56^Ni over time scales of seconds or days. However, the degree of mixing allowed by the observed images is much smaller than current 3D calculations for Rayleigh-Taylor dominated deflagration fronts. The images also require a central region of no or little Ca but iron group elements indicative of burning under sufficiently high densities for electron capture taking place, i.e., burning prior to a significant pre-expansion of the WD.Comment: 18 pages, 14 figures. Accepted for publication in Ap

An oral bait vaccination approach for the Tasmanian devil facial tumor diseases

Introduction: The Tasmanian devil (Sarcophilus harrisii) is the largest extant carnivorous marsupial. Since 1996, its population has declined by 77% primarily due to a clonal transmissible tumor, known as devil facial tumor (DFT1) disease. In 2014, a second transmissible devil facial tumor (DFT2) was discovered. DFT1 and DFT2 are nearly 100% fatal.Areas covered: We review DFT control approaches and propose a rabies-style oral bait vaccine (OBV) platform for DFTs. This approach has an extensive safety record and was a primary tool in large-scale rabies virus elimination from wild carnivores across diverse landscapes. Like rabies virus, DFTs are transmitted by oral contact, so immunizing the oral cavity and stimulating resident memory cells could be advantageous. Additionally, exposing infected devils that already have tumors to OBVs could serve as an oncolytic virus immunotherapy. The primary challenges may be identifying appropriate DFT-specific antigens and optimization of field delivery methods.Expert opinion: DFT2 is currently found on a peninsula in southern Tasmania, so an OBV that could eliminate DFT2 should be the priority for this vaccine approach. Translation of an OBV approach to control DFTs will be challenging, but the approach is feasible for combatting ongoing and future disease threats

Cheeky Witnessing

Feminists witness legal worlds as they observe, document, and share nothing less than the reproduction of life itself. The world of the abortion trail, where people and things move across borders to change life’s reproduction, has generated a rich plurality of feminist witnessing. In observing how feminist activists improvise with sources, figures and objects of legal consciousness on the abortion trail, this paper seeks to contribute to critical understanding of that plurality, particularly as it emerges in diaspora space. Focusing on Murphy’s concept of immodest witnessing, with its attention to bodies, protocols and apparatuses as constituents of knowledge, the paper thinks with the diasporic feminist activist performance group, Speaking of I.M.E.L.D.A., about how they used self-examination, collective collaboration, and knowledge-sharing on the trail to repeal of Ireland’s Eighth Amendment. The paper argues that their improvisation with legal consciousness of reproductive choice enacts ‘cheeky witnessing’. Cheeky witnessing has three dynamics as a method of observation. First, it is messy and irreverent in innovating with names to display the mixed genealogies of sources of feminist knowledge. Second, cheeky witnessing generates novel subject-figures, such as migrant cleaners, who make knowing connections between different reproductive labourers as observers of the trail in diaspora space. Third, cheeky witnessing places funny objects, knickers in this instance, so as to join up particular public locations and make them more, if unevenly, comfortable for sexual and reproductive bodies. Cheeky witnessing show us how committed and partial practices play a role in speaking across interests and experiences, in stretching the legal imagination, and in sustaining the everyday grind of making a better world

Pilot to policy: statewide dissemination and implementation of evidence-based treatment for traumatized youth

Abstract Background A model for statewide dissemination of evidence-based treatment (EBT) for traumatized youth was piloted and taken to scale across North Carolina (NC). This article describes the implementation platform developed, piloted, and evaluated by the NC Child Treatment Program to train agency providers in Trauma-Focused Cognitive Behavioral Therapy using the National Center for Child Traumatic Stress Learning Collaborative (LC) Model on Adoption & Implementation of EBTs. This type of LC incorporates adult learning principles to enhance clinical skills development as part of training and many key implementation science strategies while working with agencies and clinicians to implement and sustain the new practice. Methods Clinicians (n = 124) from northeastern NC were enrolled in one of two TF-CBT LCs that lasted 12 months each. During the LC clinicians were expected to take at least two clients through TF-CBT treatment with fidelity and outcomes monitoring by trainers who offered consultation by phone and during trainings. Participating clinicians initiated treatment with 281 clients. The relationship of clinician and client characteristics to treatment fidelity and outcomes was examined using hierarchical linear regression. Results One hundred eleven clinicians completed general training on trauma assessment batteries and TF-CBT. Sixty-five clinicians met all mastery and fidelity requirements to meet roster criteria. One hundred fifty-six (55%) clients had fidelity-monitored assessment and TF-CBT. Child externalizing, internalizing, and post-traumatic stress symptoms, as well as parent distress levels, decreased significantly with treatment fidelity moderating child PTSD outcomes. Since this pilot, 11 additional cohorts of TF-CBT providers have been trained to these roster criteria. Conclusion Scaling up or outcomes-oriented implementation appears best accomplished when training incorporates: 1) practice-based learning, 2) fidelity coaching, 3) clinical assessment and outcomes-oriented treatment, 4) organizational skill-building to address barriers for agencies, and 5) linking clients to trained clinicians via an online provider roster. Demonstrating clinician performance and client outcomes in this pilot and subsequent cohorts led to legislative support for dissemination of a service array of EBTs by the NC Child Treatment Program

Identification of metal-poor stars using the artificial neural network

Context. Identification of metal-poor stars among field stars is extremely useful for studying the structure and evolution of the Galaxy and of external galaxies. Aims. We search for metal-poor stars using the artificial neural network (ANN) and extend its usage to determine absolute magnitudes. Methods. We have constructed a library of 167 medium-resolution stellar spectra (R ~ 1200) covering the stellar temperature range of 4200 to 8000 K, log g range of 0.5 to 5.0, and [Fe/H] range of −3.0 to +0.3 dex. This empirical spectral library was used to train ANNs, yielding an accuracy of 0.3 dex in [Fe/H] , 200 K in temperature, and 0.3 dex in log g. We found that the independent calibrations of near-solar metallicity stars and metal-poor stars decreases the errors in Teff and log g by nearly a factor of two. Results. We calculated Teff, log g, and [Fe/H] on a consistent scale for a large number of field stars and candidate metal-poor stars. We extended the application of this method to the calibration of absolute magnitudes using nearby stars with well-estimated parallaxes. A better calibration accuracy for MV could be obtained by training separate ANNs for cool, warm, and metal-poor stars. The current accuracy of MV calibration is ±0.3 mag. Conclusions. A list of newly identified metal-poor stars is presented. The MV calibration procedure developed here is reddening-independent and hence may serve as a powerful tool in studying galactic structure

In-Situ and Experimental Evidence for Acidic Weathering of Rocks and Soils on Mars

Experimental data for alteration of synthetic Martian basalts at pH=0-1 indicate that chemical fractionations at low pH are vastly different from those observed during terrestrial weathering. Rock analyses from Gusev crater are well described by the relationships apparent from low pH experimental alteration data. A model for rock surface alteration is developed which indicates that a leached alteration zone is present on rock surfaces at Gusev. This zone is not chemically fractionated to a large degree from the underlying rock interior, indicating that the rock surface alteration process has occurred at low fluid-to-rock ratio. The geochemistry of natural rock surfaces analyzed by APXS is consistent with a mixture between adhering soil/dust and the leached alteration zone. The chemistry of rock surfaces analyzed after brushing with the RAT is largely representative of the leached alteration zone. The chemistry of rock surfaces analyzed after grinding with the RAT is largely representative of the interior of the rock, relatively unaffected by the alteration process occurring at the rock surface. Elemental measurements from the Spirit, Opportunity, Pathfinder and Viking 1 landing sites indicate that soil chemistry from widely separated locations is consistent with the low-pH, low fluid to rock ratio alteration relationships developed for Gusev rocks. Soils are affected principally by mobility of FeO and MgO, consistent with alteration of olivine-bearing basalt and subsequent precipitation of FeO and MgO bearing secondary minerals as the primary control on soil geochemistry