Novel Si(1-x)Ge(x)/Si heterojunction internal photoemission long wavelength infrared detectors

There is a major need for long-wavelength-infrared (LWIR) detector arrays in the range of 8 to 16 microns which operate with close-cycle cryocoolers above 65 K. In addition, it would be very attractive to have Si-based infrared (IR) detectors that can be easily integrated with Si readout circuitry and have good pixel-to-pixel uniformity, which is critical for focal plane array (FPA) applications. Here, researchers report a novel Si(1-x)Ge(x)/Si heterojunction internal photoemission (HIP) detector approach with a tailorable long wavelength infrared cutoff wavelength, based on internal photoemission over the Si(1-x)Ge(x)/Si heterojunction. The HIP detectors were grown by molecular beam epitaxy (MBE), which allows one to optimize the device structure with precise control of doping profiles, layer thickness and composition. The feasibility of a novel Si(1-x)Ge(x)/Si HIP detector has been demonstrated with tailorable cutoff wavelength in the LWIR region. Photoresponse at wavelengths 2 to 10 microns are obtained with quantum efficiency (QE) above approx. 1 percent in these non-optimized device structures. It should be possible to significantly improve the QE of the HIP detectors by optimizing the thickness, composition, and doping concentration of the Si(1-x)Ge(x) layers and by configuring the detector for maximum absorption such as the use of a cavity structure. With optimization of the QE and by matching the barrier energy to the desired wavelength cutoff to minimize the thermionic current, researchers predict near background limited performance in the LWIR region with operating temperatures above 65K. Finally, with mature Si processing, the relatively simple device structure offers potential for low-cost producible arrays with excellent uniformity

Response time fluctuations in the sustained attention to response task predict performance accuracy and meta-awareness of attentional states

Previous research suggests that response time (RT) patterns in the Sustained Attention to Response Task(SART) differentially predict different features of mind wandering but it is unknown how they relate to meta-awareness of attentional states. We applied principal component analysis to blocks of non-target (go) trials prior to target(no-go) trials and attentional state and meta-awareness probes in the SART and identified three distinct patterns that replicated those observed in previous research. A stable response rate was associated with superior target performance, whereas RT acceleration prior to targets was associated with poorer target performance. Self-reported attentional state was not significantly predicted by any of the pattern components. By contrast, meta-awareness was independently associated with two distinct RT fluctuation patterns with evidence that each pattern was specifically related to either meta-awareness of off-task or on-task states. These results suggest that mind wandering and meta-awareness of attentional states have distinct and overlapping imprints on RT patterns in the SART. We conclude by highlighting implications of these results for introspective methods and the measurement of mind wandering

Containment calculation for Burzet

Burzet is a proposed intermediate-yield underground test of a nuclear explosive at the Nevada Test Site. The possible existence of a high Paleozoic scarp and fault within 100 m of the proposed working point created concern as to their effect on the containment of the radioactive gases. A calculation of the expected stress wave interaction at the scarp and fault demonstrates that the effects are negligible. Results of the calculation are those expected from an event in a homogeneous media and are thus consistent with good containment experience on numerous previous detonations of similar yield, depth of burial, and medium properties

Northern Bobwhite Survival and Productivity in Relation to Food Supplementation

Northern bobwhite (Colinus virginianus; hereafter, bobwhite) populations have experienced a 3.4% decline annually nation-wide from 1966 to 2018. Limitations on resources, such as food, can regulate population growth. Supplemental food could alleviate resource limitation by raising carrying capacity, leading to increased survival and breeding productivity. Studies have shown higher survival rates and higher nest production when food is supplemented; however, repeating experiments in different contexts allows for strong inference. Our objectives were to assess how supplemental food influenced survival and breeding productivity of resident and translocated bobwhite during a 2-year study on public lands in Leon County, Florida, USA within the Apalachicola National Forest. In accordance with the food limitation hypothesis, we predicted that provisioning of supplemental food would have a positive influence on survival rates and nest productivity. We split the study site into 4 approximately 400-ha zones and randomly assigned 2 treatment (fed) and 2 control (unfed) replicates. Treatment and control zones were flipped during the second field season. Treatments received approximately 1.75 bushels of milo (Sorghum bicolor)/acre 2 times/month year-round via broadcast spreader. We radio-marked 205 bobwhites (102 treatment, 103 control) from February 2019 through October 2020. Individuals were tracked 3–4 times/week for location and survival via radio-telemetry to estimate the breeding season survival and reproduction rates. We estimated survival rates using the Kaplan-Meier product limit estimator. The survival rate during the breeding seasons was higher on average for treatment zones (x̄ = 0.38, standard error [SE] = 0.040) than for control zones (x̄ = 0.29, SE = 0.045). We also observed that 79% of nests found were located in treatment zones compared to 21% in control zones. Our results suggest that food supplementation can improve survival rates and nest production of bobwhite in a food-limited landscape

Hypnotherapy for procedural pain, itch, and state anxiety in children with acute burns: A feasibility and acceptability study protocol

Background: Burns and related procedures are painful and distressing for children, exposing them to acute and chronic sequelae that can negatively afect their physiological, psychological, and social functions. Non-pharmacological interventions such as distraction techniques are benefcial adjuncts to pharmacological agents for procedural pain, state anxiety, and itch in children with burns but have limitations (e.g. lack of research on burn-related itch, tailoring, and consensus on optimal treatment). Hypnotherapy is a non-pharmacological intervention that can be tailored for varied settings and populations with evidence of beneft for itch and superior efectiveness in comparison to other non-pharmacological interventions for children’s procedural pain and state anxiety. Thus, children with burns can beneft from hypnotherapy as an adjunct to pharmacological agents. Yet, in paediatric burns, rigorous studies of efectiveness are limited and no studies have been identifed that screen for hypnotic suggestibility, an important predictor of hypnotherapy outcomes. Considering potential barriers to the delivery of hypnotherapy in paediatric burns, the proposed study will examine the feasibility and acceptability of hypnotic suggestibility screening followed by hypnotherapy for procedural pain, state anxiety, and itch in children with acute burns. Methods: An observational mixed-methods feasibility and acceptability study will be conducted over 15 weeks. Eligible children (N = 30) aged 4 to 16 years presenting to a paediatric burns outpatient centre in a metropolitan children’s hospital in Australia with acute burns requiring dressing changes will be included. Eligible parents of children (N = up to 30) and clinicians who perform dressing changes (N = up to 20) will also be included. Child participants screened as having medium to high suggestibility as assessed by behavioural measures will receive hypnotherapy during dressing changes. A process evaluation will target feasibility and acceptability as primary outcomes and implementation (i.e. fdelity in delivery), reach, potential efectiveness, and adoption of evaluation procedures and intervention as secondary outcomes. Discussion: Ethical approval was obtained from the Queensland Children’s Hospital and Health Service ethics committee. Results will be published in peer-reviewed publications and conference proceedings. The fndings will guide the design of future trials on the efectiveness of hypnotherapy and inform the development of child-centred hypnotic interventions in children with burns. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN1262000098895

Proteasome-Dependent Disruption of the E3 Ubiquitin Ligase Anaphase-Promoting Complex by HCMV Protein pUL21a

This work is licensed under a Creative Commons Attribution 4.0 International License.The anaphase-promoting complex (APC) is an E3 ubiquitin ligase which controls ubiquitination and degradation of multiple cell cycle regulatory proteins. During infection, human cytomegalovirus (HCMV), a widespread pathogen, not only phosphorylates the APC coactivator Cdh1 via the multifunctional viral kinase pUL97, it also promotes degradation of APC subunits via an unknown mechanism. Using a proteomics approach, we found that a recently identified HCMV protein, pUL21a, interacted with the APC. Importantly, we determined that expression of pUL21a was necessary and sufficient for proteasome-dependent degradation of APC subunits APC4 and APC5. This resulted in APC disruption and required pUL21a binding to the APC. We have identified the proline-arginine amino acid pair at residues 109–110 in pUL21a to be critical for its ability to bind and regulate the APC. A point mutant virus in which proline-arginine were mutated to alanines (PR-AA) grew at wild-type levels. However, a double mutant virus in which the viral ability to regulate the APC was abrogated by both PR-AA point mutation and UL97 deletion was markedly more attenuated compared to the UL97 deletion virus alone. This suggests that these mutations are synthetically lethal, and that HCMV exploits two viral factors to ensure successful disruption of the APC to overcome its restriction on virus infection. This study reveals the HCMV protein pUL21a as a novel APC regulator and uncovers a unique viral mechanism to subvert APC activity

Effect of Food Distribution on Northern Bobwhite Resource Selection

Supplemental feeding is a common management tactic used to increase survival and reproduction of northern bobwhite (Colinus virginianus; hereafter, bobwhite). Different supplemental feeding methods alter the distribution of resources across a landscape in unique ways and may influence the space use and resource selection of target species differently. Predators may concentrate their movements near fed sites, and different distributions of supplemental feed may encourage bobwhite to concentrate their movements closer to feed than other areas, thereby altering the potential for predator-prey interactions near feed. We used radio-tracked locations and movements in areas with stationary feeders (“feeder fed”) and nonsupplementally fed (“unfed”; study 1, year 1) or nonstationary “broadcast fed” (study 2, year 2) areas to compare resource selection within a Bayesian framework. Second- and third-order resource selection functions indicated bobwhite were more likely to occur in proximity to feeders and feedlines when available, but bobwhite resource selection was more strongly affected by feeders. These results demonstrate that different distributions of food resources can affect prey resource selection, potentially altering the probability of overlap between nontarget predator and target prey species. Managers of bobwhite populations should broadcast feed instead of using feeders to avoid concentrations of bobwhites, which may lead to reduced survival