2,486 research outputs found
Structural dynamics payload loads estimates: User guide
This User Guide with an overview of an integration scheme to determine the response of a launch vehicle with multiple payloads. Chapter II discusses the software package associated with the integration scheme together with several sample problems. A short cut version of the integration technique is also discussed. The Guide concludes with a list of references and the listings of the subroutines
Large-scale network organization in the avian forebrain: a connectivity matrix and theoretical analysis
Many species of birds, including pigeons, possess demonstrable cognitive capacities, and some are capable of cognitive feats matching those of apes. Since mammalian cortex is laminar while the avian telencephalon is nucleated, it is natural to ask whether the brains of these two cognitively capable taxa, despite their apparent anatomical dissimilarities, might exhibit common principles of organisation on some level. Complementing recent investigations of macro-scale brain connectivity in mammals, including humans and macaques, we here present the first large-scale wiring diagram for the forebrain of a bird. Using graph theory, we show that the pigeon telencephalon is organised along similar lines to that of a mammal. Both are modular, small-world networks with a connective core of hub nodes that includes prefrontal-like and hippocampal structures. These hub nodes are, topologically speaking, the most central regions of the pigeon's brain, as well as being the most richly connected, implying a crucial role in information flow. Overall, our analysis suggests that indeed, despite the absence of cortical layers and close to 300 million years of separate evolution, the connectivity of the avian brain conforms to the same organisational principles as the mammalian brain
Hybrid Quarkonia with High Statistics from NRQCD
We have studied the O(mv^6) effects in NRQCD on the spectrum of heavy
quarkonia and compare our results for different lattices (quenched and
dynamical). We also report on an investigation into hybrid states within the
framework of NRQCD. This suggests that the lowest lying hybrid is around the
B^* \bar B threshold and 3 standard deviations above the B \bar B.Comment: 3 pages, LaTeX2e, 4 figures, uses styles [espcrc2, epsf], talk
presented at Lattice 9
NRQCD on an anisotropic lattice
We present preliminary results for the Upsilon spectrum on an anisotropic
lattice using the improved O(mv^6) NRQCD Hamiltonian. We find accurate results
can be obtained in moderate computer times and that they agree with earlier
results on an isotropic lattice.Comment: 3 pages, LATEX2e, talk presented at LATTICE '98 by R.R. Horgan, uses
styles[espcrc2,epsfig
Constitutional Law - Supreme Court Declares New Standard of Proof for Groups Alleging Submergence in a Multimember Election District - Whitcomb v. Chavis, 403 U.S. 124 (1971).
The Partial Information Decomposition of Generative Neural Network Models
In this work we study the distributed representations learnt by generative neural network models. In particular, we investigate the properties of redundant and synergistic information that groups of hidden neurons contain about the target variable. To this end, we use an emerging branch of information theory called partial information decomposition (PID) and track the informational properties of the neurons through training. We find two differentiated phases during the training process: a first short phase in which the neurons learn redundant information about the target, and a second phase in which neurons start specialising and each of them learns unique information about the target. We also find that in smaller networks individual neurons learn more specific information about certain features of the input, suggesting that learning pressure can encourage disentangled representations
Heavy-light decay constants from clover heavy quark action in QCD with two flavors of dynamical quarks
We present results on an analysis of the decay constants f_B and f_Bs with
two flavours of sea quark. The calculation has been carried out on 3 different
bare gauge couplings and 4 sea quark masses at each gauge coupling, with
m_pi/m_rho ranging from 0.8 to 0.6. We employ the Fermilab formalism to perform
calculations with heavy quarks whose mass is in the range of the b-quark. A
detailed comparison with a quenched calculation using the same action is made
to elucidate the effects due to the sea quarks.Comment: Contribution to Lattice 99 (Heavy Quarks). Latex file, uses
espcrc2.sty and epsf.sty. 3 pages, 3 encapsulated postscript figure
Shining a Light on Intestinal Traffic
Inflammatory bowel disease (IBD), encompassing Crohn's disease and ulcerative colitis, is associated with enhanced leukocyte infiltration to the gut, which is directly linked to the clinical aspects of these disorders. Thus, leukocyte trafficking is a major target for IBD therapy. Past and emerging techniques to study leukocyte trafficking both in vitro and in vivo have expanded our knowledge of the leukocyte migration process and the role of inhibitors. Various strategies have been employed to target chemokine- and integrin-ligand interactions within the multistep adhesion cascade and the S1P/S1PR1 axis in leukocyte migration. Though there is an abundance of preclinical data demonstrating efficacy of leukocyte trafficking inhibitors, many have yet to be confirmed in clinical studies. Vigilance for toxicity and further research is required into this complex and emerging area of IBD therapy
The political and scientific challenges in evaluating compulsory drug treatment centers in Southeast Asia
BACKGROUND: In Vietnam, like many countries in Southeast Asia, the commonly used approach of center-based compulsory drug treatment (CCT) has been criticized on human rights ground. Meanwhile, community-based voluntary methadone maintenance treatment (MMT) has been implemented for nearly a decade with promising results. Reform-minded leaders have been seeking empirical evidence of the costs and effectiveness associated with these two main treatment modalities. Conducting evaluations of these treatments, especially where randomization is not ethical, presents challenges. The aim of this paper is to discuss political challenges and methodological issues when conducting cost-effectiveness studies within the context of a non-democratic Southeast Asian country. METHODS: A retrospective analysis of the political and scientific challenges that were experienced in the study design, sample size determination, government approval and ethics approvals, participant recruitment, data collection, and determination of sources, and quantification of cost and effectiveness data was undertaken. As a consequence of the non-randomized design, analysis of patient characteristics for both treatment types was undertaken to identify the magnitude of baseline group differences. Concordance between self-reported heroin use and urine drug testing was undertaken to determine the reliability of self-report data in a politically challenging environment. RESULTS: We demonstrate that conducting research around compulsory treatment in a non-democratic society is feasible, yet it is politically challenging and requires navigation between science and politics. We also demonstrate that engagement with the government decision makers in the research conception, implementation, and dissemination of the results increases the likelihood of research evidence being considered for change in a contentious drug policy area. CONCLUSIONS: Local empirical evidence on the comparative cost-effectiveness of CCT and MMT in a Southeast Asian setting is critical to consideration of more holistic, humane, and effective drug-dependence treatment approaches, but the garnering of such evidence is very challenging.Thu Vuong, Nhu Nguyen , Giang Le, Marian Shanahan, Robert Ali and Alison Ritte
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