2,928 research outputs found
The Theory and Principles of War
The nature and theory of war, consideration of the interrelationship of the military and the nonmilitary factors in the development of strategic concepts, a brief review of classic concepts of strategy, and the contribution they have made to modern strategic concepts
Federal Income Tax Amendments of 1944
Present 1944 changes of the federal income tax statutes consist of amendments made by the Revenue Act of 1943, and the Individual Income Tax Act of 1944 passed in February and May of this year respectively. Additional changes are unlikely. It is anticipated therefore, that there can now be presented an analysis of statutory changes which must be considered in the preparation of returns for the year 1944
Synthesis and Photophysical Characterization of Near-Ir Probes for Bioanalytical Applications.
The research presented in this dissertation involves the synthesis and photophysical characterization of a series of tricarbocyanine dyes which can be used as fluorescent labels for bioanalytical applications. All of these dyes were synthesized to contain a heavy-atom modification to enhance k\sb{\rm isc} through spin-orbit coupling and a functional group (isothiocyanate or succinimidyl ester) which is reactive towards primary amines. The spectroscopic characterization of the various chromophores was examined using absorbance and fluorescence measurements, time-correlated fluorescence, and flash photolysis. The dyes exhibit absorbance and fluorescence maxima in the near-IR (750-810 nm) with large (200,000 M\sp{-1}cm\sp{-1}) and \Phi\sb{\rm f}\sim0.05-0.15. Dyes which contain the heavy-atom modification possessed absorbance maxima which were similar (differences of only 1-2 nm) and similar fluorescence maxima (differences of only 1-2 nm), but have fluorescence lifetimes (\tau\sb{\rm f}) which were different and which were dependent upon the heavy-atom modification (I = 908 ps, F = 831 ps). The apparent inverse heavy-atom effect was studied by examining the triplet-state photophysics of these chromophores by laser-induced flash photolysis. Various photophysical constants were determined including the intersystem crossing rate (k\sb{\rm isc}), internal conversion rate (k\sb{\rm ic}), and \Phi\sb{\rm t}. The results from these experiments indicate that k\sb{\rm isc} is increasing with the heavier atom modification, but that k\sb{\rm ic} decreasing possibly due to steric interactions of the heavy-atom modification with the chromophore restricting the vibrational interconversions of the dye. These dyes were examined as possible fluorescent labels for amino acid determination and DNA sequencing employing fluorescence detection. The experimental results with the capillary electrophoretic separation of dye-labeled amino acids indicated that in the presence of CH\sb3OH in the running buffer, the detection of the dye-labeled amino acids exhibited excellent signal-to-noise ratios corresponding to low mass detection limits for dye-labeled arginine (21 zmol). Additionally, these dyes were examined as possible dye labels for a Sanger DNA sequencing protocol employing near-IR fluorescence lifetime determination of dye-labeled dideoxynucleotides. Experimental results that these dyes efficiently react with an amine modified dideoxyguanosine triphosphate. The effect of the extension reaction conditions on the dye-labeled ddNTP was also examined
Gender identity development in self-disclosed gay men in Hidalgo County, Texas
Although gay individuals are now more visible than ever, homosexuality remains among the most stigmatized of personal identities. It is because of the various variables associated with coming out and being out and the multitude of persons affected by an individuals\u27 decision to disclose his orientation that are the focus of this research.
This research is designed to document the “coming out” experiences of self disclosed homosexual men, in Hidalgo County, Texas a predominately Mexican American, Catholic community, This research will look at the identity change that takes place when people choose to disclose their homosexual identity to other people. In particular, what meanings do gay men give to coming out and what are the factors that have either enabled or hindered them from coming out to other people
Kinematics and dynamics are not represented independently in motor working memory: Evidence from an interference study
Our capacity to learn multiple dynamic and visuomotor tasks is limited by the time between the presentations of the tasks.
When subjects are required to adapt to equal and opposite
position-dependent visuomotor rotations (Krakauer et al., 1999) or velocity-dependent force fields (Brashers-Krug et al., 1996) in quick succession, interference occurs that prevents the first task from being consolidated in memory. In contrast, such interference is not observed between learning a positiondependent visuomotor rotation and an acceleration-dependent force field. On the basis of this finding, it has been argued that internal models of kinematic and dynamic sensorimotor transformations are learned independently (Krakauer et al., 1999).
However, these findings are also consistent with the perturbations interfering only if they depend on the same kinematic variable. We evaluated this hypothesis using kinematic and dynamic transformations matched in terms of the kinematic variable on which they depend. Subjects adapted to a positiondependent visuomotor rotation followed 5 min later by a position-dependent rotary force field either with or without visual feedback of arm position. The force field tended to rotate the hand in the direction opposite to the visuomotor rotation. To assess learning, all subjects were retested 24 hr later on the visuomotor rotation, and their performance was compared with a control group exposed only to the visuomotor rotation on both days. Adapting to the position-dependent force field, both with and without visual feedback, impaired learning of the visuomotor rotation. Thus, interference between our kinematic and dynamic transformations was observed, suggesting that the key determinant of interference is the kinematic variable on which the transformation depends
DNA methylation profiling to assess pathogenicity of BRCA1 unclassified variants in breast cancer
Germline pathogenic mutations in BRCA1 increase risk of developing breast cancer. Screening for mutations in BRCA1 frequently identifies sequence variants of unknown pathogenicity and recent work has aimed to develop methods for determining pathogenicity. We previously observed that tumor DNA methylation can differentiate BRCA1-mutated from BRCA1-wild type tumors. We hypothesized that we could predict pathogenicity of variants based on DNA methylation profiles of tumors that had arisen in carriers of unclassified variants. We selected 150 FFPE breast tumor DNA samples [47 BRCA1 pathogenic mutation carriers, 65 BRCAx (BRCA1-wild type), 38 BRCA1 test variants] and analyzed a subset (n=54) using the Illumina 450K methylation platform, using the remaining samples for bisulphite pyrosequencing validation. Three validated markers (BACH2, C8orf31, and LOC654342) were combined with sequence bioinformatics in a model to predict pathogenicity of 27 variants (independent test set). Predictions were compared with standard multifactorial likelihood analysis. Prediction was consistent for c.5194-12G>A (IVS 19-12 G>A) (P>0.99); 13 variants were considered not pathogenic or likely not pathogenic using both approaches. We conclude that tumor DNA methylation data alone has potential to be used in prediction of BRCA1 variant pathogenicity but is not independent of estrogen receptor status and grade, which are used in current multifactorial models to predict pathogenicity
A Linear-Nonlinear Formulation of Einstein Equations for the Two-Body Problem in General Relativity
A formulation of Einstein equations is presented that could yield advantages
in the study of collisions of binary compact objects during regimes between
linear-nonlinear transitions. The key idea behind this formulation is a
separation of the dynamical variables into i) a fixed conformal 3-geometry, ii)
a conformal factor possessing nonlinear dynamics and iii) transverse-traceless
perturbations of the conformal 3-geometry.Comment: 7 pages, no figure
Irrotational binary neutron stars in quasiequilibrium
We report on numerical results from an independent formalism to describe the
quasi-equilibrium structure of nonsynchronous binary neutron stars in general
relativity. This is an important independent test of controversial numerical
hydrodynamic simulations which suggested that nonsynchronous neutron stars in a
close binary can experience compression prior to the last stable circular
orbit. We show that, for compact enough stars the interior density increases
slightly as irrotational binary neutron stars approach their last orbits. The
magnitude of the effect, however, is much smaller than that reported in
previous hydrodynamic simulations.Comment: 4 pages, 2 figures, revtex, accepted for publication in Phys. Rev.
Revised Relativistic Hydrodynamical Model for Neutron-Star Binaries
We report on numerical results from a revised hydrodynamic simulation of
binary neutron-star orbits near merger. We find that the correction recently
identified by Flanagan significantly reduces but does not eliminate the
neutron-star compression effect. Although results of the revised simulations
show that the compression is reduced for a given total orbital angular
momentum, the inner most stable circular orbit moves to closer separation
distances. At these closer orbits significant compression and even collapse is
still possible prior to merger for a sufficiently soft EOS. The reduced
compression in the corrected simulation is consistent with other recent studies
of rigid irrotational binaries in quasiequilibrium in which the compression
effect is observed to be small. Another significant effect of this correction
is that the derived binary orbital frequencies are now in closer agreement with
post-Newtonian expectations.Comment: Submitted to Phys. Rev.
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