2,120 research outputs found
David Gillespie\u27s \u27Teen Brain\u27: a valid argument let down by selective science and over-the-top claims
Screen time has arguably become the most concerning aspect of development for modern-day parents. A 2015 poll identified children\u27s excessive screen time as the number one concern for parents, overtaking more traditional concerns such as obesity and not getting enough physical activity
Direct observation of magnetization dynamics generated by nano-contact spin-torque vortex oscillators
Time-resolved scanning Kerr microscopy has been used to directly image the
magnetization dynamics of nano-contact (NC) spin-torque vortex oscillators
(STVOs) when phase-locked to an injected microwave (RF) current. The Kerr
images reveal free layer magnetization dynamics that extend outside the NC
footprint, where they cannot be detected electrically, but which are crucial to
phase-lock STVOs that share common magnetic layers. For a single NC, dynamics
were observed not only when the STVO frequency was fully locked to that of the
RF current, but also for a partially locked state characterized by periodic
changes in the core trajectory at the RF frequency. For a pair of NCs, images
reveal the spatial character of dynamics that electrical measurements show to
have enhanced amplitude and reduced linewidth. Insight gained from these images
may improve understanding of the conditions required for mutual phase-locking
of multiple STVOs, and hence enhanced microwave power emission.Comment: 10 pages, 3 figure
Sedimentation in a semi-arid zone reservoir in Australia determined by 137 Cs
Sediment has accumulated behind a masonry dam built in the 1880s in the Barrier Range, north - west of Broken Hill, New South Wales, Australia. The contributing catchment has an area of 12.5 ha, and is used for rangeland grazing for sheep and goats. It is estimated from surveys and measurements of heavy metals and caesium-137 that over 1000 tonnes of sediment have accumulated in the reservoir since its inception. Approximately one-third of the sediment has been delivered since the mid-1950s.
Sediment accumulation is equivalent to a catchment erosion rate of 0.78 t ha-1 y-1 prior to the mid-1950s, whereas from the mid-1950s to the present it is 0.59 t ha-1 y-1. This indicates that the trap efficiency of the reservoir has decreased and/or the sediment supply has become relative ly exhausted and/or there has been a progressive increase in vegetation cover related to reduced grazing pressures. The estimated rates of erosion are considerably lower than for other sites in semi-arid New South Wales probably because sediment has been transported in overflows of the damwall
Moderate Nrf2 Activation by Genetic Disruption of Keap1 Has Sex-Specific Effects on Bone Mass in Mice
Keap1 is a negative controller of the transcription factor Nrf2 for its activity. The Keap1/Nrf2 signaling pathway has been considered as a master regulator of cytoprotective genes, and exists in many cell types including osteoblasts and osteoclasts. Our previous study shows Nrf2 deletion decreases bone formation. Recent studies show hyperactivation of Nrf2 causes osteopenia in Keap1−/− mice, and Keap1−/− osteoblasts have significantly less proliferative potential than Keap1+/− osteoblasts. We aimed to examine if moderate Nrf2 activation by disruption of Keap1 impacts bone metabolism. We examined bone phenotype of Keap1 heterozygotic mice (Ht) in comparison with Keap1 wild type (WT) mice. Deletion or knockdown of Keap1 enhanced the gene expression of Nrf2, ALP and wnt5a in cultured primary osteoblasts compared to WT control. In male mice, compared with their age-matched littermate WT controls, Keap1 Ht mice showed significant increase in bone formation rate (+30.7%, P = 0.0029), but did not change the ultimate force (P < 0.01). The osteoclast cell numbers (−32.45%, P = 0.01) and surface (−32.58%, P = 0.03) were significantly reduced by Keap1 deficiency in male mice. Compared to male WT mice, serum bone resorption marker in male Keap1 Ht mice was significantly decreased. Our data suggest that moderate Nrf2 activation by disruption of Keap1 improved bone mass by regulating bone remodeling in male mice
Translational autoregulation of BZW1 and BZW2 expression by modulating the stringency of start codon selection.
The efficiency of start codon selection during ribosomal scanning in eukaryotic translation initiation is influenced by the context or flanking nucleotides surrounding the AUG codon. The levels of eukaryotic translation initiation factors 1 (eIF1) and 5 (eIF5) play critical roles in controlling the stringency of translation start site selection. The basic leucine zipper and W2 domain-containing proteins 1 and 2 (BZW1 and BZW2), also known as eIF5-mimic proteins, are paralogous human proteins containing C-terminal HEAT domains that resemble the HEAT domain of eIF5. We show that translation of mRNAs encoding BZW1 and BZW2 homologs in fungi, plants and metazoans is initiated by AUG codons in conserved unfavorable initiation contexts. This conservation is reminiscent of the conserved unfavorable initiation context that enables autoregulation of EIF1. We show that overexpression of BZW1 and BZW2 proteins enhances the stringency of start site selection, and that their poor initiation codons confer autoregulation on BZW1 and BZW2 mRNA translation. We also show that overexpression of these two proteins significantly diminishes the effect of overexpressing eIF5 on stringency of start codon selection, suggesting they antagonize this function of eIF5. These results reveal a surprising role for BZW1 and BZW2 in maintaining homeostatic stringency of start codon selection, and taking into account recent biochemical, genetic and structural insights into eukaryotic initiation, suggest a model for BZW1 and BZW2 function
Deterring Serious and Chronic Offenders
This chapter examines ways of deterring serious and chronic offenders based on evidence from the Pathways to Desistance Study, which addresses the issue of perceptions of deterrence and looks into the mechanisms of deterrence for serious offenders. After a brief overview of the Pathways study, the chapter reviews empirical evidence that demonstrates the rationality of high-risk adolescents regarding involvement in crime. It argues that offenders take into account rational-choice perceptions in their offending decisions and goes on to discuss the elasticity and malleability of these perceptions, and whether adolescent offenders act differently when they change risk and cost perceptions. It also considers policy efforts aimed at maximizing deterrence among adolescent offenders and concludes by outlining future directions for theory and research
Emergence of a STAT3 mutated NK clone in LGL leukemia
AbstractLarge granular lymphocyte (LGL) leukemia is a chronic clonal lymphoproliferative disorder. Here, a T-LGL leukemia patient developed NK-LGL leukemia with residual leukemic T-LGL. TCRVβ usage and CDR3 sequence drifts were observed with disease progression. A STAT3 S614R mutation was identified in NK but not T-cells in the mixed leukemic stage. Multiple, non-dominant T-cell clones with distinct STAT3 mutations were present throughout. Our results suggest that T and NK-LGL leukemia may share common pathogenesis mechanisms and that STAT3 mutation alone is insufficient to bring about clonal expansion. Mutational and immunological monitoring may provide diagnostic and therapeutic significance in LGL leukemia
Multiple myeloma presenting as CEA-producing rectal cancer
We report the case of a 57-year-old patient with multiple myeloma, characterized by extramedullary involvement of the rectum at presentation. Malignant plasma cells were found to produce carcinoembryonic antigen (CEA), a tumor antigen more commonly associated with rectal adenocarcinomas
The introduction of multiparametric MRI in prostate cancer management: Does it aid the urologist?
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