1,357 research outputs found
A Dynamic Game on Network Topology for Counterinsurgency Applications
Successful military operations are increasingly reliant upon an advanced understanding of relevant networks and their topologies. The methodologies of network science are uniquely suited to inform senior military commanders; however, there is a lack of research in the application of these methods in a realistic military scenario. This study creates a dynamic game on network topology to provide insight into the effectiveness of offensive targeting strategies determined by various centrality measures given limited states of information and varying network topologies. Improved modeling of complex social behaviors is accomplished through incorporation of a distance-based utility function. Moreover, insights into effective defensive strategies are gained through incorporation of a hybrid model of network regeneration. Model functions and parameters are thoroughly presented, followed by a detailed sensitivity analysis of factors. Two designed experiments fully investigate the significance of factor main effects and two-factor interactions. Results show select targeting criteria utilizing uncorrelated network measures are found to outperform others given varying network topologies and defensive regeneration methods. Furthermore, the attacker state of information is only significant given certain defending network topologies. The costs of direct relationships significantly impact optimal methods of regeneration, whereas restructuring methods are insignificant. Model applications are presented and discussed
An evaluation of linear acoustic theory for a hovering rotor
Linear acoustic calculations are compared with previously reported data for a small-scale hovering rotor operated at high tip Mach numbers. A detailed calculated description of the distributions of blade surface pressure and shear stress due to skin friction is presented. The noise due to skin friction and loading, in the rotor disk plane, is small compared to thickness noise. The basic conclusions of Boxwell et al about the importance of nonlinear effects are upheld. Some approximations involved in the current theories for the inclusion of nonlinear effects are discussed. Using a model nonlinear problem, it is shown that to use the acoustic analogy, good knowledge of the flowfield is required
Hyperfine-structure study in the P sequence of 23 Na using quantum-beam spectroscopy
Describes use of the quantum-beat method to study hyperfine structure in the 5 2 P 3/2 and 6 2 P 3/2 states of 23 Na. A pulsed dye laser, frequency-doubled into the UV region, was used to excite sodium atoms abruptly in a beam. The fluorescent light was recorded with a fast transient digitiser, interfaced to a micro-computer. Theoretical calculations using many-body perturbation theory were performed for the entire P sequence measured so far, taking polarisation and correlation effects into account separately. Very good agreement between experimental and theoretical values was obtained
Oregon School-Based Health Centers: Descriptive Analysis of a Patient Satisfaction Survey
Oregon’s School Based Health Centers (SBHCs) have grown from five in 1986 to the 41 state certified centers currently in operation. The centers provide developmentally appropriate primary care and behavioral health care services to elementary, middle, and high school sites. SBHC program goals include increasing student access to care, and improving both health and educational outcomes. In the 2000-2001 service year, the Oregon SBHC program began the administration of a new patient satisfaction survey designed to measure satisfaction with services, access, receipt of prevention messages, and number of missed classes. A proportional random survey sample was achieved with a 98% response rate. Results indicate that SBHC patients had high levels of satisfaction and compliance, an increased likelihood of accessing care, high levels of compliance and satisfaction with services, decreased time from school for health care reasons, and were likely to have received one or more prevention messages. This experience demonstrates how public health surveillance can be incorporated into a SBHC clinical setting with minimal disruption to services and can inform SBHC program evaluation and improvement
Hepatitis e Virus Genotype 3 Genomes from RNA-Positive but Serologically Negative Plasma Donors Have CUG as the Start Codon for ORF3
Hepatitis E virus (HEV) is a pathogen that causes hepatitis worldwide. Molecular studies have identified HEV RNA in blood products although its significance is not understood. This study was undertaken to characterize HEV genomes in asymptomatic plasma donors from Sweden and Germany lacking anti-HEV. Complete open reading frames (ORFs) were obtained from HEV strains in 5 out of 18 plasma donors who tested positive for HEV RNA. All strains had CUG as the start codon of ORF3, while 147 GenBank strains all had AUG as the start codon (p < 0.0001). This substitution was found in both interrelated and unrelated strains belonging to different phylogenetic clades. The HEV strains from the seronegative plasma donors had no other substitution in common, which may be why the CUG substitution seems to explain the seronegativity
Multimodal Chemical Imaging of Amyloid Plaque Polymorphism Reveals A beta Aggregation Dependent Anionic Lipid Accumulations and Metabolism
Amyloid plaque formation constitutes one of the main pathological hallmarks of Alzheimer’s disease (AD) and is suggested to be a critical factor driving disease pathogenesis. Interestingly, in patients that display amyloid pathology but remain cognitively normal, Aβ deposits are predominantly of diffuse morphology suggesting that cored plaque formation is primarily associated with cognitive deterioration and AD pathogenesis. Little is known about the molecular mechanism responsible for conversion of monomeric Aβ into neurotoxic aggregates and the predominantly cored deposits observed in AD. The structural diversity among Aβ plaques, including cored/compact- and diffuse, may be linked to their distinct Aβ profile and other chemical species including neuronal lipids. We developed a novel, chemical imaging paradigm combining matrix assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) and fluorescent amyloid staining. This multimodal imaging approach was used to probe the lipid chemistry associated with structural plaque heterogeneity in transgenic AD mice (tgAPPSwe) and was correlated to Aβ profiles determined by subsequent laser microdissection and immunoprecipitation-mass spectrometry. Multivariate image analysis revealed an inverse localization of ceramides and their matching metabolites to diffuse and cored structures within single plaques, respectively. Moreover, phosphatidylinositols implicated in AD pathogenesis, were found to localize to the diffuse Aβ structures and correlate with Aβ1–42. Further, lysophospholipids implicated in neuroinflammation were increased in all Aβ deposits. The results support previous clinical findings on the importance of lipid disturbances in AD pathophysiology and associated sphingolipid processing. These data highlight the potential of multimodal imaging as a powerful technology to probe neuropathological mechanisms
Beta-delayed-neutron studies of Sb and I performed with trapped ions
Beta-delayed-neutron (n) spectroscopy was performed using the
Beta-decay Paul Trap and an array of radiation detectors. The n
branching ratios and energy spectra for Sb and I were
obtained by measuring the time of flight of recoil ions emerging from the
trapped ion cloud. These nuclei are located at the edge of an isotopic region
identified as having n branching ratios that impact the r-process
abundance pattern around the A~130 peak. For Sb and I,
n branching ratios of 14.6(11)%, 17.6(28)%, and 7.6(28)% were
determined, respectively. The n energy spectra obtained for Sb
and I are compared with results from direct neutron measurements, and
the n energy spectrum for Sb has been measured for the first
time
Regulation of the fibrosis and angiogenesis promoter SPARC/osteonectin in human adipose tissue by weight change, leptin, insulin, and glucose
This is the final version of the article. Available from the publisher via the DOI in this record.OBJECTIVE: Matricellular Secreted Protein, Acidic and Rich in Cysteine (SPARC), originally discovered in bone as osteonectin, is a mediator of collagen deposition and promotes fibrosis. Adipose tissue collagen has recently been found to be linked with metabolic dysregulation. Therefore, we tested the hypothesis that SPARC in human adipose tissue is influenced by glucose metabolism and adipokines. RESEARCH DESIGN AND METHODS: Serum and adipose tissue biopsies were obtained from morbidly obese nondiabetic subjects undergoing bariatric surgery and lean control subjects for analysis of metabolic markers, SPARC, and various cytokines (RT-PCR). Additionally, 24 obese subjects underwent a very-low-calorie diet of 1,883 kJ (450 kcal)/day for 16 weeks and serial subcutaneous-abdominal-adipose tissue (SCAT) biopsies (weight loss: 28 +/- 3.7 kg). Another six lean subjects underwent fast-food-based hyperalimentation for 4 weeks (weight gain: 7.2 +/- 1.6 kg). Finally, visceral adipose tissue explants were cultured with recombinant leptin, insulin, and glucose, and SPARC mRNA and protein expression determined by Western blot analyses. RESULTS: SPARC expression in human adipose tissue correlated with fat mass and was higher in SCAT. Weight loss induced by very-low-calorie diet lowered SPARC expression by 33% and increased by 30% in adipose tissue of subjects gaining weight after a fast-food diet. SPARC expression was correlated with leptin independent of fat mass and correlated with homeostasis model assessment-insulin resistance. In vitro experiments showed that leptin and insulin potently increased SPARC production dose dependently in visceral adipose tissue explants, while glucose decreased SPARC protein. CONCLUSIONS: Our data suggest that SPARC expression is predominant in subcutaneous fat and its expression and secretion in adipose tissue are influenced by fat mass, leptin, insulin, and glucose. The profibrotic effects of SPARC may contribute to metabolic dysregulation in obesity.This work was supported by Diabetes UK, Swedish Research
Council (11285), University Hospital of Linkoping
Research Funds; Diabetes Research Centre of Linkoping
University; and the Gamla Tjaenarinnor Foundation.
No potential conflicts of interest relevant to this article
were reported.
Parts of this study were presented in abstract form at
the 69th Scientific Sessions of the American Diabetes
Association, New Orleans, Louisiana, 5–9 June 2009
Low-lying level structure of Cu and its implications on the rp process
The low-lying energy levels of proton-rich Cu have been extracted
using in-beam -ray spectroscopy with the state-of-the-art -ray
tracking array GRETINA in conjunction with the S800 spectrograph at the
National Superconducting Cyclotron Laboratory at Michigan State University.
Excited states in Cu serve as resonances in the
Ni(p,)Cu reaction, which is a part of the rp-process in
type I x-ray bursts. To resolve existing ambiguities in the reaction Q-value, a
more localized IMME mass fit is used resulting in ~keV. We derive
the first experimentally-constrained thermonuclear reaction rate for
Ni(p,)Cu. We find that, with this new rate, the
rp-process may bypass the Ni waiting point via the Ni(p,)
reaction for typical x-ray burst conditions with a branching of up to
40. We also identify additional nuclear physics uncertainties that
need to be addressed before drawing final conclusions about the rp-process
reaction flow in the Ni region.Comment: 8 pages, accepted for Phys. Rev.
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