239 research outputs found
Recommended from our members
Texas Business Review, July 1977
College Enrollment Shifts Anticipate Current Job Market; San Antonio: A Military, Trade and Service Center; The High Price of HousingBureau of Business Researc
Recommended from our members
Texas Business Review, January 1977
How Oil Supports Prosperity in Texas; El Paso Economic Profile; Construction Activity and the Tax Reform Act of 1976Bureau of Business Researc
Quantifying Entanglement Production of Quantum Operations
The problem of entanglement produced by an arbitrary operator is formulated
and a related measure of entanglement production is introduced. This measure of
entanglement production satisfies all properties natural for such a
characteristic. A particular case is the entanglement produced by a density
operator or a density matrix. The suggested measure is valid for operations
over pure states as well as over mixed states, for equilibrium as well as
nonequilibrium processes. Systems of arbitrary nature can be treated, described
either by field operators, spin operators, or any other kind of operators,
which is realized by constructing generalized density matrices. The interplay
between entanglement production and phase transitions in statistical systems is
analysed by the examples of Bose-Einstein condensation, superconducting
transition, and magnetic transitions. The relation between the measure of
entanglement production and order indices is analysed.Comment: 20 pages, Revte
The PHENIX Experiment at RHIC
The physics emphases of the PHENIX collaboration and the design and current
status of the PHENIX detector are discussed. The plan of the collaboration for
making the most effective use of the available luminosity in the first years of
RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program
available at http://www.rhic.bnl.gov/phenix
Heparin decreases blood pressure and response to exogenous endothelin but does not protect against chronic experimental cyclosporine nephropathy
Cyclosporine nephrotoxicity is caused by renal arteriolar vasoconstriction and tubulointerstitial fibrosis. Endothelin has been proposed as a major mediator of these phenomena. Heparin inhibits vascular smooth muscle cell proliferation and lowers blood pressure by regulating endogenous endothelin 1 production. In a model of chronic cyclosporine nephrotoxicity in the rat, animals were treated with cyclosporine alone, cyclosporine plus heparin, and heparin alone for 28 days. Independent experiments determined that these doses of heparin resulted in a marked decrease in responsivity to exogenous endothelin. Despite this, there were no beneficial effects on renal structure or function in this animal model of chronic cyclosporine nephrotoxicity. Thus, the role of endothelin in the pathogenesis of the chronic tubulointerstitial changes and arteriolopathy in this model is probably minor
Riding a golf cart versus walking: a study on the physiological and performance differences in tournament golf
Golf demands sustained physical effort and effective fatigue management, especially in competitive play. Allowing players to ride golf carts in elite play has raised concerns about potential performance advantages, yet well-controlled studies are lacking. This study examined the effects of golf cart use on physiological, physical and cognitive outcomes in competitive golfers. Sixteen males (mean age: 21 ± 3 years; handicap: 2.3 ± 3.7) completed two randomised competitive rounds on a championship course (6587m; 19°C), either walking with a caddie or riding a golf cart. Physiological measures included activity energy expenditure (Actiheart), core temperature, heart rate and perceived exertion (0–100). Physical outcomes were step count, carry distance, clubhead speed, ball speed and muscle power. Cognitive workload (NASA-Task Load Index) was assessed post-round. The step count and activity energy expenditure were significantly higher for walking than using a golf cart (17,007 ± 1708 vs. 6274 ± 1111 steps; 880 ± 279 vs. 456 ± 155 kilocalories). Core temperature was higher for walking at holes 6, 12, and 18 (p = 0.022). The heart rate increased across the round when walking but decreased while using a cart (p < 0.01), and post-round exertion was higher for walking (41 ± 19 vs. 25 ± 14 and p < 0.001). Carry distance, clubhead and ball speed did not differ. NASA-Task Load Index subscales of physical demand and performance (reverse scored) were higher for walking. Relative to walking, golf cart use lowered internal physiological and external physical load, without impairing muscle power or shot performance. Cognitively, walking imposed higher physical strain and reduced perceived performance. Further research should explore whether these physiological, physical and cognitive outcomes impact performance across multiday tournaments
On Relativistic Quantum Information Properties of Entangled Wave Vectors of Massive Fermions
We study special relativistic effects on the entanglement between either
spins or momenta of composite quantum systems of two spin-1/2 massive
particles, either indistinguishable or distinguishable, in inertial reference
frames in relative motion. For the case of indistinguishable particles, we
consider a balanced scenario where the momenta of the pair are well-defined but
not maximally entangled in the rest frame while the spins of the pair are
described by a one-parameter () family of entangled bipartite states. For
the case of distinguishable particles, we consider an unbalanced scenario where
the momenta of the pair are well-defined and maximally entangled in the rest
frame while the spins of the pair are described by a one-parameter ()
family of non-maximally entangled bipartite states. In both cases, we show that
neither the spin-spin () nor the momentum-momentum () entanglements
quantified by means of Wootters' concurrence are Lorentz invariant quantities:
the total amount of entanglement regarded as the sum of these entanglements is
not the same in different inertial moving frames. In particular, for any value
of the entangling parameters, both and -entanglements are attenuated
by Lorentz transformations and their parametric rates of change with respect to
the entanglements observed in a rest frame have the same monotonic behavior.
However, for indistinguishable (distinguishable) particles, the change in
entanglement for the momenta is (is not) the same as the change in entanglement
for spins. As a consequence, in both cases, no entanglement compensation
between spin and momentum degrees of freedom occurs.Comment: 21 pages, 8 figure
Collaborative International Research in Clinical and Longitudinal Experience Study in NMOSD
OBJECTIVE: To develop a resource of systematically collected, longitudinal clinical data and biospecimens for assisting in the investigation into neuromyelitis optica spectrum disorder (NMOSD) epidemiology, pathogenesis, and treatment. METHODS: To illustrate its research-enabling purpose, epidemiologic patterns and disease phenotypes were assessed among enrolled subjects, including age at disease onset, annualized relapse rate (ARR), and time between the first and second attacks. RESULTS: As of December 2017, the Collaborative International Research in Clinical and Longitudinal Experience Study (CIRCLES) had enrolled more than 1,000 participants, of whom 77.5% of the NMOSD cases and 71.7% of the controls continue in active follow-up. Consanguineous relatives of patients with NMOSD represented 43.6% of the control cohort. Of the 599 active cases with complete data, 84% were female, and 76% were anti-AQP4 seropositive. The majority were white/Caucasian (52.6%), whereas blacks/African Americans accounted for 23.5%, Hispanics/Latinos 12.4%, and Asians accounted for 9.0%. The median age at disease onset was 38.4 years, with a median ARR of 0.5. Seropositive cases were older at disease onset, more likely to be black/African American or Hispanic/Latino, and more likely to be female. CONCLUSION: Collectively, the CIRCLES experience to date demonstrates this study to be a useful and readily accessible resource to facilitate accelerating solutions for patients with NMOSD
Diving into the vertical dimension of elasmobranch movement ecology
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements
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