How dark the sky: the JWST backgrounds

We describe the sources of stray light and thermal background that affect JWST observations; report actual backgrounds as measured from commissioning and early science observations; compare those background levels to pre-launch predictions; estimate the impact of the backgrounds on science performance; and explore how the backgrounds probe the achieved configuration of the deployed observatory. We find the observatory is limited by the irreducible astrophysical backgrounds, rather than scattered stray light and thermal self-emission, for all wavelengths $\lambda < 12.5$ micron, thus meeting the level 1 requirement. This result was not assured given the open architecture and thermal challenges of JWST, and is the result of meticulous attention to stray light and thermal issues in the design, construction, integration, and test phases. From background considerations alone, JWST will require less integration time in the near-infrared compared to a system that just met the stray light requirements; as such, JWST will be even more powerful than expected for deep imaging at 1--5 micron. In the mid-infrared, the measured thermal backgrounds closely match pre-launch predictions. The background near 10 micron is slightly higher than predicted before launch, but the impact on observations is mitigated by the excellent throughput of MIRI, such that instrument sensitivity will be as good as expected pre-launch. These measured background levels are fully compatible with JWST's science goals and the Cycle 1 science program currently underway.Comment: Submitted to the "JWST Overview" special issue of PAS

Prediction model of future academic impact for young scientists

Previous studies focused on the characteristics of elicit scientists, or the early identification of high-potential scientists, but neglected career development research of ordinary young scientists. Using scientometrics and CV methods, the present study aims to establish statistic models in order to explore young scientists&#39; career development, and predict their future academic impact. Predictors at 2009 were divided into four categories: publication indicators, scholar relationship indicators, scholar relationship indicators and research theme indicators, and these indicators were used to predict h-index at 2014. Predictive models were established separately in each category using stepwise regression, and finally a comprehensive model was built. Our result shows that hindex and total number of paper published could significantly predict scientific impact in the future. To improve academic impact, young scientists need to carry out extensive cooperation and play a key role in the cooperation, need to have the research experience in developed countries, and to reduce their research specialization.</p

Emitted and Reflected Radiance Calibration of two Large Area Cavity Blackbodies Using the NIST TXR

The emissivity and radiance of two Large Area Cavity Blackbodies (LABBs) were calibrated using the NIST Thermal Transfer Radiometer (TXR) in a thermal vacuum chamber with a warm ambient background at Ball Aerospace and Technologies Corporation. In addition to calibrating these quantities for a single viewing configuration, the radiance and emissivity were measured with the TXR as a function of linear position from the center of the cavity and angular position relative to the normal to the cavity plane. These results and supported modeling will be presented

PAMs ameliorates the imiquimod-induced psoriasis-like skin disease in mice by inhibition of translocation of NF-κB and production of inflammatory cytokines

<div><p>Psoriasis is a chronic and persistent inflammatory skin disease seriously affecting the quality of human life. In this study, we reported an ancient formula of Chinese folk medicine, the natural plant antimicrobial solution (PAMs) for its anti-inflammatory effects and proposed the primary mechanisms on inhibiting the inflammatory response in TNF-α/IFN-γ-induced HaCaT cells and imiquimod-induced psoriasis-like skin disease mouse model. Two main functional components of hydroxysafflor Yellow A and allantoin in PAMs were quantified by HPLC to be 94.2±2.2 and 262.9±12.5 μg/mL respectively. PAMs could significantly reduce the gene expression and inflammatory cytokines production of Macrophage-Derived Chemokine (MDC), IL-8 and IL-6 in TNF-α/IFN-γ-induced HaCaT cells. PAMs also significantly ameliorates the psoriatic-like symptoms in a mouse model with the evaluation scores for both the single (scales, thickness, erythema) and cumulative features were in the order of blank control < Dexamethasone < PAMs < 50% ethanol < model groups. The results were further confirmed by hematoxylin-eosin staining, RT-qPCR and immunohistochemistry. The down-regulated gene expression of <i>IL-8</i>, <i>TNF-α</i>, <i>ICAM-1 and IL-23</i> in mouse tissues was consistent with the results from those of the HaCaT cells. The inhibition of psoriasis-like skin inflammation by PAMs was correlated with the inactivation of the translocation of P65 protein into cellular nucleus, indicating the inhibition of the inflammatory NF-κB signaling pathway. Taken together, these findings suggest that PAMs may be a promising drug candidate for the treatment of inflammatory skin disorders, such as psoriasis.</p></div

Effects of PAMs on erythema, scaling and thickening in imiquimod-induced mouse skin.

<p>A: Phenotypical presentation of mouse back skin after 6 days’ treatment. B: The scores of scales, thickness, erythema and the cumulative scores are shown for each group. The data are shown as mean± S.D (n = 6). Significant differences compared to model group: *<i>p</i> < 0.05.</p

PAMs ameliorates the psoriasis-like symptoms and skin inflammation in imiquimod-induced mice.

<p>A: Histopathological investigation in each group (×100). Black arrows represent the presence of horny layer and granular layer. B: Immunohistochemistry analysis was performed for Ki67 and ICAM-1 protein of the back skin of psoriatic mice, PAMs treatment could effectively decrease the expression of Ki67 and ICAM-1 protein (×100). Red arrows represent the overexpression of Ki67 and ICAM-1 protein. C: Epidermal thickness was measured. Data are the mean values ± SD (n = 5). D: PAMs treatment led to the significant decrease of TNF-α levels in the serum of each group. #<i>p</i> < 0.05 <i>vs</i> control group; *<i>p</i> < 0.05 <i>vs</i> model group. Bar = 100 μm.</p

Inhibitory effects of PAMs on NF-κB activation and nuclear translocation in HaCaT cells.

<p>A: Cellular localization of p65 was analyzed by immunofluorescence staining. HaCaT cells were pretreated with or without 3.0% (v/v) PAMs or 1.5% (v/v) ethanol for 6 h and incubated with TNF-α and IFN-γ (each 10.0 ng/mL) for 30 min, later, the cells were incubated with anti-p65 and Cy3-conjugated secondary antibodies subsequently. Arrows indicate that NF-κB does not translocate to the nucleus. Images are representative of three independent experiments. B: The translocation rate was counted. ##<i>p</i> < 0.01 vs control group; **<i>p</i> < 0.01 vs model group. Bar = 50μm.</p