Trion Species-Resolved Quantum Beats in MoSe2

Monolayer photonic materials offer a tremendous potential for on-chip optoelectronic devices. Their realization requires knowledge of optical coherence properties of excitons and trions that have so far been limited to nonlinear optical experiments carried out with strongly inhomogenously broadened material. Here we employ h-BN encapsulated and electrically gated MoSe2 to reveal coherence properties of trion-species directly in the linear optical response. Autocorrelation measurements reveal long dephasing times up to T2=1.16+-0.05 ps for positively charged excitons. Gate dependent measurements provide evidence that the positively-charged trion forms via spatially localized hole states making this trion less prone to dephasing in the presence of elevated hole carrier concentrations. Quantum beat signatures demonstrate coherent coupling between excitons and trions that have a dephasing time up to 0.6 ps, a two-fold increase over those in previous reports. A key merit of the prolonged exciton/trion coherences is that they were achieved in a linear optical experiment, and thus are directly relevant to applications in nanolasers, coherent control, and on-chip quantum information processing requiring long photon coherence.Comment: 21 pages, 6 figures, 2 SOI figure

Development of a real-time qPCR assay for quantification of covert baculovirus infections in a major African crop pest

Many pathogens and parasites are present in host individuals and populations without any obvious signs of disease. This is particularly true for baculoviruses infecting lepidopteran hosts, where studies have shown that covert persistent viral infections are almost ubiquitous in many species. To date, the infection intensity of covert viruses has rarely been quantified. In this study, we investigated the dynamics of a covert baculovirus infection within the lepidopteran crop pest Spodoptera exempta. A real-time quantitative polymerase chain reaction (qPCR) procedure using a 5' nuclease hydrolysis (TaqMan) probe was developed for specific detection and quantification of Spodoptera exempta nucleopolyhedrovirus (SpexNPV). The qPCR assay indicated that covert baculovirus dynamics varied considerably over the course of the host life-cycle, with infection load peaking in early larval instars and being lowest in adults and final-instar larvae. Adult dissections indicated that, contrary to expectation, viral load aggregation was highest in the head, wings and legs, and lowest in the thorax and abdomen. The data presented here have broad implications relating to our understanding of transmission patterns of baculoviruses and the role of covert infections in host-pathogen dynamics

Outcomes of a teacher-led reading intervention for elementary students at-risk for behavioral disorders

This is the publisher's version, also found here: http://cec.metapress.com/content/g8686u4nu0p8772l/?p=1258705a1fcb41948563bb666b6ae215&pi=2To date, reports of reading interventions for students at risk for emotional/behavioral disorders (E/BD) that have been published in refereed journals have involved sustained support by university or school-site personnel. This study examined the efficacy and feasibility of a reading intervention that 2 general education teachers implemented in inclusive settings to support 7 first-grade students at risk for E/BD and reading difficulties. Results of a multiple baseline design revealed lasting improvements in reading fluency for all students, accompanied by decreases in variability of academic engagement for 4 students. Although intervention goals, procedures, and outcomes exceeded teacher expectations, social validity ratings for some students declined between the onset and the conclusion of the intervention. This article presents limitations, future directions, and educational implications

The Effects of Wetted Ice on Dynamic Stability over a Rewarming Period

BACKGROUND During half time or breaks in play cryotherapy is often applied for analgesia for minor musculoskeletal sport injury, however the effect of cryotherapy on dynamic stability is debated. A risk factor for further lower limb injury may be heightened due to a reduction in dynamic postural stability. OBJECTIVES The purpose of the current study was to investigate the effects of wetted-ice applied for 20-minutes at the ankle on dynamic stability using the star excursion balance test, immediately-post exposure and over a rewarming period of 30-minutes. MATERIALS AND METHODS Twenty-two healthy male athletes that regular took part in land-based sport were assessed on reach directions of Anterior (Ant), Posteromedial (PM), and Posterolateral (PL) using the modified star excursion balance test (mSEBT) on the non-dominant limb. Thermal imaging quantified skin surface temperature (Tsk) over lateral and medial regions. Participants were tested pre-intervention, exposed to 15-minutes wetted-ice cryotherapy application, immediately-post and up to 30-minutes post intervention at 10-minute intervals. RESULTS Significant decreases in Tsk over the medial and lateral regions of the ankle (p < 0.05) not returning to pre-cooling temperatures at 30-minutes post. Significant decrease in reach -distance scores (ANT, PL and PM) pre-immediately post and at 10, 20 and 30-minutes post cryotherapy exposure. CONCLUSION Following wetted ice application to the non-dominant ankle, dynamic postural stability was adversely affected for up to 30-minutes post exposure demonstrated through a decrease in reach scores for ANT, PL and PM directions. Functional performance which requires stabilising mechanisms may be negatively affected and contribute to a heightened risk of injury or further injury in consideration of the findings

Sun exposure behaviour, seasonal vitamin D deficiency, and relationship to bone health in adolescents

YesContext: Vitamin D is essential for bone health in adolescence, where there is rapid bone mineral content accrual. As cutaneous sun-exposure provides vitamin D, there is no recommended oral intake for UK adolescents. Objective: Assess seasonal vitamin D status and its contributors in white Caucasian adolescents, and examine bone health in those found deficient. Design: Prospective cohort study. Setting: Six schools in Greater Manchester, UK. Participants: 131 adolescents, 12–15 years. Intervention(s): Seasonal assessment of circulating 25-hydroxyvitamin D (25OHD), personal sunexposure and dietary vitamin D. Adolescents deficient (25OHD <10 ng/mL/25 nmol/L) in ≥one season underwent dual-energy X-ray absorptiometry (lumbar spine, femoral neck), with bone mineral apparent density (BMAD) correction for size, and peripheral quantitative computed tomography (distal radius) for volumetric (v)BMD. Main Outcome Measure: Serum 25OHD; BMD. Results: Mean 25OHD was highest in September: 24.1 (SD 6.9) ng/mL and lowest in January: 15.5 (5.9) ng/mL. Over the year, 16% were deficient in ≥one season and 79% insufficient (25OHD <20 ng/mL/50 nmol/L) including 28% in September. Dietary vitamin D was low year-round while personal sun-exposure was seasonal and predominantly across the school week. Holidays accounted for 17% variation in peak 25OHD (p<0.001). Nineteen adolescents underwent bone assessment, which showed low femoral neck BMAD versus matched reference data (p=0.0002), 3 with Z≤ -2.0 distal radius trabecular vBMD. Conclusions: Sun-exposure levels failed to provide adequate vitamin D, ~one-quarter adolescents insufficient even at summer-peak. Seasonal vitamin D deficiency was prevalent and those affected had low BMD. Recommendations on vitamin D acquisition are indicated in this age-group.The Bupa Foundation (Grant number TBF-M10-017)

Positive regulation of c-Myc by cohesin is direct, and evolutionarily conserved

AbstractContact between sister chromatids from S phase to anaphase depends on cohesin, a large multi-subunit protein complex. Mutations in sister chromatid cohesion proteins underlie the human developmental condition, Cornelia de Lange syndrome. Roles for cohesin in regulating gene expression, sometimes in combination with CCCTC-binding factor (CTCF), have emerged. We analyzed zebrafish embryos null for cohesin subunit rad21 using microarrays to determine global effects of cohesin on gene expression during embryogenesis. This identified Rad21-associated gene networks that included myca (zebrafish c-myc), p53 and mdm2. In zebrafish, cohesin binds to the transcription start sites of p53 and mdm2, and depletion of either Rad21 or CTCF increased their transcription. In contrast, myca expression was strongly downregulated upon loss of Rad21 while depletion of CTCF had little effect. Depletion of Rad21 or the cohesin-loading factor Nipped-B in Drosophila cells also reduced expression of myc and Myc target genes. Cohesin bound the transcription start site plus an upstream predicted CTCF binding site at zebrafish myca. Binding and positive regulation of the c-Myc gene by cohesin is conserved through evolution, indicating that this regulation is likely to be direct. The exact mechanism of regulation is unknown, but local changes in histone modification associated with transcription repression at the myca gene were observed in rad21 mutants

Understanding Galaxy Formation via Near-Infrared Surveys in the 2020s

A discussion of science cases in extragalactic astrophysics and galaxy formation that wide-area space-based infrared surveys will address in the 2020s. <p/