271 research outputs found
Toward Agent-based Modeling of the U.S. Department of Defense Acquisition System
The systems development, procurement and sustainment of a nation\u27s military equipment is vital to its national interests, but the process is complex, constantly changing and highly adaptive, as well as time consuming and costly. The U.S. Department of Defense (DoD) expends both large amounts of capital and manpower to equip its armed forces. This research seeks to identify opportunities to gain better insight into the functioning of the defense acquisition system, building on previous simulations. A case is made that the DoD Requirements, Planning Acquisition, Technology and Logistics System is a complex adaptive system that has characteristics appropriate for exploration with agent-based modeling. This paper reviews relevant literature, existing models and presents preliminary analysis on an agent-based simulation of the DoD acquisition system. This research finds that agent-based modeling can provide insights to inform new acquisition theory
CHANG-ES VI: Probing Supernova Energy Deposition in Spiral Galaxies Through Multi-Wavelength Relationships
How a galaxy regulates its SNe energy into different
interstellar/circumgalactic medium components strongly affects galaxy
evolution. Based on the JVLA D-configuration C- (6 GHz) and L-band (1.6 GHz)
continuum observations, we perform statistical analysis comparing
multi-wavelength properties of the CHANG-ES galaxies. The high-quality JVLA
data and edge-on orientation enable us for the first time to include the halo
into the energy budget for a complete radio-flux-limited sample. We find tight
correlations of with the mid-IR-based SFR. The normalization of
our relation is 2-3 times of
those obtained for face-on galaxies, probably a result of enhanced IR
extinction at high inclination. We also find tight correlations between and the SNe energy injection rate , indicating
the energy loss via synchrotron radio continuum accounts for of
, comparable to the energy contained in CR electrons. The
integrated C-to-L-band spectral index is for non-AGN
galaxies, indicating a dominance by the diffuse synchrotron component. The
low-scatter /
relationships have super-linear logarithmic slopes at in L-band
(/) while consistent with linear in C-band
(/). The super-linearity could be naturally
reproduced with non-calorimeter models for galaxy disks. Using Chandra halo
X-ray measurements, we find sub-linear relations.
These results indicate that the observed radio halo of a starburst galaxy is
close to electron calorimeter, and a galaxy with higher SFR tends to distribute
an increased fraction of SNe energy into radio emission (than X-ray).Comment: 16 pages, 6 figures, 1 table, MNRAS in pres
Absorbent articles, especially catamenials, having improved fluid directionality
The present invention provides absorbent articles, especially sanitary napkins, containing a fluid transport layer. In-use, the transport layer directs menses to a storage layer, thereby minimizing product failure and staining of undergarments. The transport layer can protrude into, or through, a topsheet to provide very aggressive transport of vaginal discharges. Preferably, the transport layer is a layer of fibers having external capillary channels
Chemosensory Contributions of E-Cigarette Additives on Nicotine Use
While rates of smoking combustible cigarettes in the United States have trended down in recent years, use of electronic cigarettes (e-cigarettes) has dramatically increased, especially among adolescents. The vast majority of e-cigarette users consume “flavored” products that contain a variety of chemosensory-rich additives, and recent literature suggests that these additives have led to the current “teen vaping epidemic.” This review, covering research from both human and rodent models, provides a comprehensive overview of the sensory implications of e-cigarette additives and what is currently known about their impact on nicotine use. In doing so, we specifically address the oronasal sensory contributions of e-cigarette additives. Finally, we summarize the existing gaps in the field and highlight future directions needed to better understand the powerful influence of these additives on nicotine use
CHANG-ES IV: Radio continuum emission of 35 edge-on galaxies observed with the Karl G. Jansky Very Large Array in D-configuration, Data Release 1
We present the first part of the observations made for the Continuum Halos in
Nearby Galaxies, an EVLA Survey (CHANG-ES) project. The aim of the CHANG-ES
project is to study and characterize the nature of radio halos, their
prevalence as well as their magnetic fields, and the cosmic rays illuminating
these fields. This paper reports observations with the compact D configuration
of the Karl G. Jansky Very Large Array (VLA) for the sample of 35 nearby
edge-on galaxies of CHANG-ES. With the new wide bandwidth capabilities of the
VLA, an unprecedented sensitivity was achieved for all polarization products.
The beam resolution is an average of 9.6" and 36" with noise levels reaching
approximately 6 and 30 microJy per beam for C- and L-bands, respectively
(robust weighting). We present intensity maps in these two frequency bands (C
and L), with different weightings, as well as spectral index maps, polarization
maps, and new measurements of star formation rates (SFRs). The data products
described herein are available to the public in the CHANG-ES data release
available at www.queensu.ca/changes. We also present evidence of a trend among
galaxies with larger halos having higher SFR surface density, and we show, for
the first time, a radio continuum image of the median galaxy, taking advantage
of the collective signal-to-noise ratio of 30 of our galaxies. This image shows
clearly that a typical spiral galaxy is surrounded by a halo of magnetic fields
and cosmic rays.Comment: 70 pages, of which 35 pages present the data of each galax
The Pathway to Low Outlier Status in Venous Thromboembolism Events: An Analysis of Pancreatic Surgery in ACS NSQIP
Introduction: Our institution’s hepatopancreaticobiliary service (HPBS) is a high-volume pancreatic surgery service, which has demonstrated consistently low rates of symptomatic venous thromboembolism (VTE) compared to similar institutions as reported by NSQIP. We sought to determine if the HPBS’s regimented multimodal VTE prophylaxis pathway plays a role in achieving consistently low VTE rates.
Methods: We queried the ACS NSQIP Participant User File and our institution’s data from 2011-2016 for major pancreatic operations. We used Chi-squared analysis to compare the HPBS and national patient populations, and created a matched dataset based on preoperative patient factors. Univariate and multivariate analyses were performed on both the aggregate and matched data to determine independent risk factors for symptomatic VTE formation.
Results: Among 36,435 NSQIP patients, 850 (2.3%) received surgery by the HPBS. VTE rates were significantly lower for the HPBS (2.0%) compared to the national cohort (3.5%) (p=0.018); this significance was seen in the matched cohort as well (p=0.040). Upon multivariate analysis, having an operation performed by the HPBS independently conferred lower odds of VTE formation in both the aggregate (OR=0.572, p=0.024) and matched (OR=0.530, p=0.041) cohorts.
Discussion: The HPBS had statistically lower rates of symptomatic VTE compared to the national cohort as reported by NSQIP. We identified an independent protective effect of the HPBS on VTE formation, which we believe to be due, at least in part, to adherence to a high risk VTE prophylaxis pathway. This pathway could serve as a model for other institutions hoping to improve their VTE rates
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