Finite-element-analysis model and preliminary ground testing of controls-structures interaction evolutionary model reflector

Results of two different nonlinear finite element analyses and preliminary test results for the final design of the Controls-Structures Interaction Evolutionary Model are presented. Load-deflection data bases are generalized from analysis and testing of the 16-foot diameter, dish shaped reflector. Natural frequencies and mode shapes are obtained from vibrational analysis. Experimental and analytical results show similar trends; however, future test hardware modifications and finite element model refinement would be necessary to obtain better correlation. The two nonlinear analysis procedures are both adequate techniques for the analysis of prestressed structures with complex geometries

Atherosusceptible Shear Stress Activates Endoplasmic Reticulum Stress to Promote Endothelial Inflammation.

Atherosclerosis impacts arteries where disturbed blood flow renders the endothelium susceptible to inflammation. Cytokine activation of endothelial cells (EC) upregulates VCAM-1 receptors that target monocyte recruitment to atherosusceptible regions. Endoplasmic reticulum (ER) stress elicits EC dysregulation in metabolic syndrome. We hypothesized that ER plays a central role in mechanosensing of atherosusceptible shear stress (SS) by signaling enhanced inflammation. Aortic EC were stimulated with low-dose TNFα (0.3 ng/ml) in a microfluidic channel that produced a linear SS gradient over a 20mm field ranging from 0-16 dynes/cm2. High-resolution imaging of immunofluorescence along the monolayer provided a continuous spatial metric of EC orientation, markers of ER stress, VCAM-1 and ICAM-1 expression, and monocyte recruitment. VCAM-1 peaked at 2 dynes/cm2 and decreased to below static TNFα-stimulated levels at atheroprotective-SS of 12 dynes/cm2, whereas ICAM-1 rose to a maximum in parallel with SS. ER expansion and activation of the unfolded protein response also peaked at 2 dynes/cm2, where IRF-1-regulated VCAM-1 expression and monocyte recruitment also rose to a maximum. Silencing of PECAM-1 or key ER stress genes abrogated SS regulation of VCAM-1 transcription and monocyte recruitment. We report a novel role for ER stress in mechanoregulation at arterial regions of atherosusceptible-SS inflamed by low-dose TNFα

First XMM-Newton observations of strongly magnetic cataclysmic variables I: spectral studies of DP Leo and WW Hor

We present an analysis of the X-ray spectra of two strongly magnetic cataclysmic variables, DP Leo and WW Hor, made using XMM-Newton. Both systems were in intermediate levels of accretion. Hard optically thin X-ray emission from the shocked accreting gas was detected from both systems, while a soft blackbody X-ray component from the heated surface was detected only in DP Leo. We suggest that the lack of a soft X-ray component in WW Hor is due to the fact that the accretion area is larger than in previous observations with a resulting lower temperature for the re-processed hard X-rays. Using a multi-temperature model of the post-shock flow, we estimate that the white dwarf in both systems has a mass greater than 1 Msun. The implications of this result are discussed. We demonstrate that the `soft X-ray excess' observed in many magnetic cataclysmic variables can be partially attributed to using an inappropriate model for the hard X-ray emission.Comment: Accepted by MNRAS as a letter, 5 pages, 2 figure

Testing and improving the numerical accuracy of the NLO predictions

I present a new and reliable method to test the numerical accuracy of NLO calculations based on modern OPP/Generalized Unitarity techniques. A convenient solution to rescue most of the detected numerically inaccurate points is also proposed.Comment: References added. 1 Table added. Version accepted for publicatio

Role of aldehyde dehydrogenase in hypoxic vasodilator effects of nitrite in rats and humans

Hypoxic conditions favour the reduction of nitrite to nitric oxide (NO) to elicit vasodilatation, but the mechanism(s) responsible for bioconversion remains ill defined. In the present study, we assess the role of aldehyde dehydrogenase 2 (ALDH2) in nitrite bioactivation under normoxia and hypoxia in the rat and human vasculature

Langley's CSI evolutionary model: Phase O

A testbed for the development of Controls Structures Interaction (CSI) technology to improve space science platform pointing is described. The evolutionary nature of the testbed will permit the study of global line-of-sight pointing in phases 0 and 1, whereas, multipayload pointing systems will be studied beginning with phase 2. The design, capabilities, and typical dynamic behavior of the phase 0 version of the CSI evolutionary model (CEM) is documented for investigator both internal and external to NASA. The model description includes line-of-sight pointing measurement, testbed structure, actuators, sensors, and real time computers, as well as finite element and state space models of major components

Multiple relocations and adolescents in out-of-home care

Children in out-of-home care often experience multiple relocations while in the system of care. This study examined the impact of these multiple relocations on the self- esteem, locus of control, sense of safety, and behavioral problems of 60 adolescent males, age 12-18 years, in the treatment programs of a child care agency located in East Tennessee. The youth were asked how may placements they had been in while in out-of- home care. Hierarchical multiple regression was used to assess the relationship between these numbers of placements and the subjects\u27 scores on the Self-Esteem Inventory, the Self-Esteem Scale, the Nowicki-Strickland Internal-External Control Scale for Children, the Mastery Scale, the Sense of Safety Scale (developed for this study by the author), and the Child Behavior Checklist Youth Self-Report, while controlling for the youths\u27 age, race, present level of care, and time at present placement. The hypothesis, that adolescents in out-of-home care who have experienced more moves while in out-of-home care will have lower self-esteem, less of an internal locus of control, lower of a sense of safety, and more behavioral problems than adolescents with fewer moves while in out-of-home care, however, was not supported by the findings. Implications for further research and improved practices in the care of children in out-of- home placements are discussed

Perceived sense of safety for children in out-of-home care who have experienced multiple moves

This study used both qualitative and quantitative methods to explore the sense of safety held by adolescent males in out-of-home care. The qualitative study used a phenomenological approach to come to understand their perception of their sense of safety, especially as it was related to moving multiple times between placements. Twelve adolescent males between the ages of 13 and 18 years were interviewed and asked how they experienced moving between placements and what made them feel safe or unsafe in the process. Their responses were categorized into major themes that included: relating to caregivers, gaining information, adapting, behavior of other youth, family issues, and types of moves. Implications for practice are discussed related to the youths\u27 responses. The quantitative portion of the study consisted of establishing the reliability and validity of the Sense of Safety Scale (SOSS), which was developed by the researcher. This scale, designed to assess the physical and psychoemotional sense of safety of youth in out-of-home care, was administered to 90 adolescent males, between the ages of 12 and 18 years, who were in various levels of foster care placement, with the majority being in residential care. The SOSS was found to have a high internal consistency with this sample. It also was found to have significant correlations with established scales that measured self-esteem, locus of control, and internalizing problem behavior, thus establishing construct validity

A 1-acetamido derivative of 6-epi-valienamine: an inhibitor of a diverse group of β-N-acetylglucosaminidases

The synthesis of an analogue of 6-epi-valienamine bearing an acetamido group and its characterisation as an inhibitor of β-N-acetylglucosaminidases are described. The compound is a good inhibitor of both human O-GlcNAcase and human β-hexosaminidase, as well as two bacterial β-N-acetylglucosaminidases. A 3-D structure of the complex of Bacteroides thetaiotaomicron BtGH84 with the inhibitor shows the unsaturated ring is surprisingly distorted away from its favoured solution phase conformation and reveals potential for improved inhibitor potency