3,181 research outputs found

    Paper Session I-A - Neutral Particle Beam Overview

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    The goal of the Neutral Particle Beam (NPB) technology program is to develop a multimission directed energy weapon (DEW) system which can function as an effective component in a Strategic Defense System. The NPB has the capability to be used as both a weapon and discriminator platform. It can kill missiles and reentry vehicles in the boost, post-boost, and mid-course portion of an ICBM trajectory as well as discriminated objects during the midcourse phase. Objects from those boosters and buses not engaged in the boost and post boost phase would be engaged once the reentry vehicles and decoys have been deployed, i.e. during the midcourse phase of the trajectory. The NPB can be used to provide a passive, active, and interactive discrimination capability against these targets. Passive discrimination is accomplished by viewing visible, ultraviolet (UV) and/or infrared (IR) emissions from targets and decoys using on-board acquisition sensors. Active discrimination is accomplished by illuminating targets and decoys with a laser tracker on-board the NPB; while Interactive discrimination is accomplished by illuminating the target with the NPB which results in the emission of X-rays and neutrons which are proportional to the mass of the target. These emitted particles are measured by a free flying detector to determine the mass of the objects. During the discrimination process target state vectors (position and velocity) can be determined which can be handed over to space-based or ground-based interceptors. All the sensors are on the same platform. This reduces data processing since sensor-to-sensor correlation is not required

    First detection of phase-dependent colliding wind X-ray emission outside the Milky Way

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    After having reported the detection of X-rays emitted by the peculiar system HD5980, we assess here the origin of this high-energy emission from additional X-ray observations obtained with XMM-Newton. This research provides the first detection of apparently periodic X-ray emission from hot gas produced by the collision of winds in an evolved massive binary outside the Milky Way. It also provides the first X-ray monitoring of a Luminous Blue Variable only years after its eruption and shows that the dominant source of the X-rays is not associated with the ejecta.Comment: 13 pages, 3 figures and 1 table, accepted for publication in ApJ (letters

    Hospital Community Benefits After the ACA: Building on State Experience

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    Analyzes hospitals' requirements to conduct community health needs assessments, financial assistance and billing and collection policies, and community benefit reporting and oversight strategies. Notes implications for federal and state law and practice

    Fabricating PFPE Membranes for Capillary Electrophoresis

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    A process has been developed for fabricating perfluoropolyether (PFPE) membranes that contain microscopic holes of precise sizes at precise locations. The membranes are to be incorporated into laboratory-on-a-chip microfluidic devices to be used in performing capillary electrophoresis. The present process is a modified version of part of the process, described in the immediately preceding article, that includes a step in which a liquid PFPE layer is cured into solid (membrane) form by use of ultraviolet light. In the present process, one exploits the fact that by masking some locations to prevent exposure to ultraviolet light, one can prevent curing of the PFPE in those locations. The uncured PFPE can be washed away from those locations in the subsequent release and cleaning steps. Thus, holes are formed in the membrane in those locations. The most straightforward way to implement the modification is to use, during the ultraviolet-curing step, an ultraviolet photomask similar to the photomasks used in fabricating microelectronic devices. In lieu of such a photomask, one could use a mask made of any patternable ultraviolet-absorbing material (for example, an ink or a photoresist)

    Reflecting on the next generation of models for community-based natural resources management

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    Community-based natural resource management (CBNRM) has been a pervasive paradigm in conservation circles for three decades. Despite many potentially attractive attributes it has been extensively critiqued from both ecological and sociological perspectives with respect to theory and practice (for example Leach et al. 1999; Berkes 2004; Fabricius et al. 2004; Blaikie 2006). Nonetheless, many successful examples exist, although an equal number have seemingly not met expectations. Is this because of poor implementation or rather a generally flawed model? If the criteria and conditions for success are so onerous that relatively few projects or situations are likely to qualify, what then is the value of the model? The questions thus become: how and what can we learn from the past theory and practice to develop a new generation of flexible, locally responsive and implementable CBNRM models, and what are likely to be the attributes of such models

    Transcriptome Analysis of Targeted Mouse Mutations Reveals the Topography of Local Changes in Gene Expression.

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    The unintended consequences of gene targeting in mouse models have not been thoroughly studied and a more systematic analysis is needed to understand the frequency and characteristics of off-target effects. Using RNA-seq, we evaluated targeted and neighboring gene expression in tissues from 44 homozygous mutants compared with C57BL/6N control mice. Two allele types were evaluated: 15 targeted trap mutations (TRAP); and 29 deletion alleles (DEL), usually a deletion between the translational start and the 3' UTR. Both targeting strategies insert a bacterial beta-galactosidase reporter (LacZ) and a neomycin resistance selection cassette. Evaluating transcription of genes in +/- 500 kb of flanking DNA around the targeted gene, we found up-regulated genes more frequently around DEL compared with TRAP alleles, however the frequency of alleles with local down-regulated genes flanking DEL and TRAP targets was similar. Down-regulated genes around both DEL and TRAP targets were found at a higher frequency than expected from a genome-wide survey. However, only around DEL targets were up-regulated genes found with a significantly higher frequency compared with genome-wide sampling. Transcriptome analysis confirms targeting in 97% of DEL alleles, but in only 47% of TRAP alleles probably due to non-functional splice variants, and some splicing around the gene trap. Local effects on gene expression are likely due to a number of factors including compensatory regulation, loss or disruption of intragenic regulatory elements, the exogenous promoter in the neo selection cassette, removal of insulating DNA in the DEL mutants, and local silencing due to disruption of normal chromatin organization or presence of exogenous DNA. An understanding of local position effects is important for understanding and interpreting any phenotype attributed to targeted gene mutations, or to spontaneous indels

    ASEE Support to Student Veterans: Results of a 2018 ASEE Leadership Roundtable

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    As industry demands for qualified science, technology, engineering, and mathematics (STEM) workers continue to increase, supporting diverse groups of students towards success in STEM may help mitigate future shortfalls in the STEM workforce. Education benefits like the post 9/11 GI Bill may provide a viable pathway for increasing the STEM-qualified, engineering technician, engineering technologist, and engineer (ETETE) workforce through the nation’s veteran population. Supporting student veterans along ETETE pathways may involve three key tasks: 1) building early awareness of ETETE pathways; 2) ensuring academic recognition for prior military work experience; and 3) providing seamless support from government agencies, academic institutions, and industry. Student veterans follow non-traditional education pathways and bring with them a wealth of diverse life experiences. Correspondingly, the growing number of veterans pursuing STEM degrees, and the diversity of this underserved group of students continues to gain the attention of faculty, administrators, and national organizations. To bolster ASEE’s support for many diverse groups to include student veterans in ETETE pathways, the ASEE president commissioned a series of leadership roundtables during the 2018 ASEE National Conference and Exposition. There, roundtables were tasked with making recommendations regarding how ASEE can support engineering education, relevant diversity research, and engagement of these diverse communities in society activities. The purpose of this paper is to report the results of the 2018 ASEE Student Veteran Leadership roundtable. This roundtable brought together a diverse group of veterans, engineering educators, and engineering student veteran researchers. Through a series of ideation exercises and discussions, the group examined the challenges student veterans traditionally face, on-going support initiatives at their home institutions, and recommended actions for ASEE to pursue in the years ahead. The topics discussed during the panel are related to previous research about the challenges faced by veteran students beyond ETETE career paths. A series of novel initiatives are presented that may assist ASEE and university administrators more broadly in adopting a fresh approach to veteran student support

    Slopes To Prevent Trapping of Bubbles in Microfluidic Channels

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    The idea of designing a microfluidic channel to slope upward along the direction of flow of the liquid in the channel has been conceived to help prevent trapping of gas bubbles in the channel. In the original application that gave rise to this idea, the microfluidic channels are parts of micro-capillary electrophoresis (microCE) devices undergoing development for use on Mars in detecting compounds indicative of life. It is necessary to prevent trapping of gas bubbles in these devices because uninterrupted liquid pathways are essential for sustaining the electrical conduction and flows that are essential for CE. The idea is also applicable to microfluidic devices that may be developed for similar terrestrial microCE biotechnological applications or other terrestrial applications in which trapping of bubbles in microfluidic channels cannot be tolerated. A typical microCE device in the original application includes, among other things, multiple layers of borosilicate float glass wafers. Microfluidic channels are formed in the wafers, typically by use of wet chemical etching. The figure presents a simplified cross section of part of such a device in which the CE channel is formed in the lowermost wafer (denoted the channel wafer) and, according to the present innovation, slopes upward into a via hole in another wafer (denoted the manifold wafer) lying immediately above the channel wafer. Another feature of the present innovation is that the via hole in the manifold wafer is made to taper to a wider opening at the top to further reduce the tendency to trap bubbles. At the time of reporting the information for this article, an effort to identify an optimum technique for forming the slope and the taper was in progress. Of the techniques considered thus far, the one considered to be most promising is precision milling by use of femtosecond laser pulses. Other similar techniques that may work equally well are precision milling using a focused ion beam, or a small diamond-tipped drill bit

    Continuity properties of measurable group cohomology

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    A version of group cohomology for locally compact groups and Polish modules has previously been developed using a bar resolution restricted to measurable cochains. That theory was shown to enjoy analogs of most of the standard algebraic properties of group cohomology, but various analytic features of those cohomology groups were only partially understood. This paper re-examines some of those issues. At its heart is a simple dimension-shifting argument which enables one to `regularize' measurable cocycles, leading to some simplifications in the description of the cohomology groups. A range of consequences are then derived from this argument. First, we prove that for target modules that are Fr\'echet spaces, the cohomology groups agree with those defined using continuous cocycles, and hence they vanish in positive degrees when the acting group is compact. Using this, we then show that for Fr\'echet, discrete or toral modules the cohomology groups are continuous under forming inverse limits of compact base groups, and also under forming direct limits of discrete target modules. Lastly, these results together enable us to establish various circumstances under which the measurable-cochains cohomology groups coincide with others defined using sheaves on a semi-simplicial space associated to the underlying group, or sheaves on a classifying space for that group. We also prove in some cases that the natural quotient topologies on the measurable-cochains cohomology groups are Hausdorff.Comment: 52 pages. [Nov 22, 2011:] Major re-write with Calvin C. Moore as new co-author. Results from previous version strengthened and several new results added. [Nov 25, 2012:] Final version now available at springerlink.co
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