2,140 research outputs found
Decoherence-Free Emergence of Macroscopic Local Realism for entangled photons in a cavity
We investigate the influence of environmental noise on polarization entangled
light generated by parametric emission in a cavity. By adopting a recently
developed separability criterion, we show that: i) self-stimulation may
suppress the detrimental influence of noise on entanglement; ii) when
self-stimulation becomes effective, a classical model of parametric emission
incorporating noise provides the same results of quantum theory for the
expectation values involved in the separability criterion. Moreover we show
that, in the macroscopic limit, it is impossible to observe violations of local
realism with measurements of -particle correlations, whatever n but finite.
These results provide an interesting example of the emergence of macroscopic
local realism in the presence of strong entanglement even in the absence of
decoherence.Comment: 1 figur
The Relation of physical self-concept, anxiety, and BMI among mexicam university students
El propĂłsito de la investigaciĂłn es conocer y relacionar los resultados del
autoconcepto fĂsico, con diferentes tipos de ansiedad y el IMC en los estudiantes
de enfermerĂa y educaciĂłn fĂsica dela penĂnsula de YucatĂĄn (MĂ©xico). La
muestra estuvo formada por 264 participantes, de los cuales 91 eran varones y
173 mujeres, con edades comprendidas entre 18 y 25 años. Nuestros datos
revelan que en el autoconcepto fĂsico, los valores obtenidos por los estudiantes
de educaciĂłn fĂsica son superiores al de los estudiantes de enfermerĂa. Los
estudiantes de enfermerĂa presentan mayores valores de ansiedad estado que
los de educaciĂłn fĂsica. La percepciĂłn que tienen los estudiantes de ciclos
superiores en prĂĄcticamente todas las dimensiones del autoconcepto es superior
a la del alumnado de ciclos inferiores. Los niveles de ansiedad disminuyen
conforme pasan de ciclos inferiores a superioresThe purpose of this paper is to know and relate the results of the various
dimensions formed by the physical self-concept with respect to the different
types of anxiety and the BMI among nursing and physical education students in
the area of the YucatĂĄn peninsula in Mexico. The study is based on a sample of
264 people, being 91 men and 173 women between the ages of 18 and 25. The
outcome shows that the values obtained by physical education students are
higher than those obtained by nursing students regarding the physical selfconcept.
Nursing students present a higher level of anxiety compared to
physical education students. The perception showed by junior and senior
students with regard to almost all dimensions of self-concept is higher than that
of freshmen and sophomore students. Anxiety level among students decreases
throughout the year
Influencia de la infecciĂłn por VIH/sida sobre algunos indicadores bioquĂmicos del estado nutricional
The main objective of this study was to analyze the influence of nutritional state among HIV-1 infected people, according to the different clinical stages referred by the CDC (Control Disease Center of the United States) in 1987, as well as the changes in the concentrations of some biochemical markers linked to nutritional state. A similar study was carried out in a control group with UltramicroELISA non-reagent healthy individuals, anthropometrically classified. Concentrations of total proteins, albumin, cholesterol, three-glycerides, urea, uric acid and creatinine were analyzed by sex and clinical group, comparing the levels obtained through a variance study. When comparing HIV-1 asymptomatic infected patients to HIV-1 and HIV-2 non infected people, the results showed a non significant increase in the level of total proteins with a significant decrease of albumin and creatinine, the latter observed only in male patients. In stage IV patients, an important decrease of cholesterol and a significant increase of the threeglicerides were found, as well as the lowest albumin levels. Urea and uric acid levels did not experience statistically significant changes. It was concluded that the study of biochemical markers is advisable, since it contributes to the detection by default of malnutrition marginal states in infected individuals.Con el objetivo de analizar la influencia de la infecciĂłn por el VIH y el estadio clĂnico de la enfermedad sobre indicadores bioquĂmicos del estado nutricional del individuo, se estudiĂł un grupo de individuos infectados y clasificados en diferentes grupos clĂnicos, de acuerdo con los criterios propuestos en 1987 por el Centro de Control de Enfermedades de los Estados Unidos, asĂ como un grupo control integrado por sujetos seronegativos al VIH y clasificados antropomĂ©tricamente con un estado nutricional normal. Se analizaron las variaciones experimentadas por las proteĂnas totales, albĂșmina, colesterol, triacilglicĂ©ridos, urea, ĂĄcido Ășrico y creatinina, segĂșn sexo y grupo clĂnico, para lo cual se realizĂł la comparaciĂłn de las medias obtenidas por medio de un anĂĄlisis de la varianza. Al compararlos con los seronegativos, se encontrĂł en los seropositivos asintomĂĄticos un incremento no significativo de las proteĂnas totales con disminuciĂłn significativa de la albĂșmina y la creatinina; esta Ășltima sĂłlo en el sexo masculino. En los pacientes del estadio IV se manifestĂł la disminuciĂłn mĂĄs importante del colesterol y un aumento significativo de los triglicĂ©ridos, asĂ como los niveles mĂĄs bajos de albĂșmina. La urea y el ĂĄcido Ășrico no experimentaron cambios con significaciĂłn estadĂstica. Se recomienda la determinaciĂłn de indicadores bioquĂmicos en la detecciĂłn de estados marginales de malnutriciĂłn por defecto en individuos VIH/SIDA
Temperature Variation of Ultra Slow Light in a Cold Gas
A model is developed to explain the temperature dependence of the group
velocity as observed in the experiments of Hau et al (Nature {\bf397}, 594
(1999)). The group velocity is quite sensitive to the change in the spatial
density. The inhomogeneity in the density and its temperature dependence are
primarily responsible for the observed behavior.Comment: 12 pages, 4 figure
Low-energy effects in brane worlds: Liennard-Wiechert potentials and Hydrogen Lamb shift
Testing extra dimensions at low-energies may lead to interesting effects. In
this work a test point charge is taken to move uniformly in the 3-dimensional
subspace of a (3+)-brane embedded in a (3++1)-space with compact and
one warped infinite spatial extra dimensions. We found that the electromagnetic
potentials of the point charge match standard Liennard-Wiechert's at large
distances but differ from them close to it. These are finite at the position of
the charge and produce finite self-energies. We also studied a localized
Hydrogen atom and take the deviation from the standard Coulomb potential as a
perturbation. This produces a Lamb shift that is compared with known
experimental data to set bounds for the parameter of the model. This work
provides details and extends results reported in a previous Letter.Comment: Manuscript (LaTeX) and 2 figure files (eps format) used by the
manuscript LaTeX fil
Exploring venlafaxine pharmacokinetic variability with a phenotyping approach, a multicentric french-swiss study (MARVEL study).
It is well known that the standard doses of a given drug may not have equivalent effects in all patients. To date, the management of depression remains mainly empirical and often poorly evaluated. The development of a personalized medicine in psychiatry may reduce treatment failure, intolerance or resistance, and hence the burden and costs of mood depressive disorders. The Geneva Cocktail Phenotypic approach presents several advantages including the "in vivo" measure of different cytochromes and transporter P-gp activities, their simultaneous determination in a single test, avoiding the influence of variability over time on phenotyping results, the administration of low dose substrates, a limited sampling strategy with an analytical method developed on DBS analysis. The goal of this project is to explore the relationship between the activity of drug-metabolizing enzymes (DME), assessed by a phenotypic approach, and the concentrations of Venlafaxine (VLX)Â +Â O-demethyl-venlafaxine (ODV), the efficacy and tolerance of VLX.
This study is a multicentre prospective non-randomized open trial. Eligible patients present a major depressive episode, MADRS over or equal to 20, treatment with VLX regardless of the dose during at least 4Â weeks. The Phenotype Visit includes VLX and ODV concentration measurement. Following the oral absorption of low doses of omeprazole, midazolam, dextromethorphan, and fexofenadine, drug metabolizing enzymes activity is assessed by specific metabolite/probe concentration ratios from a sample taken 2Â h after cocktail administration for CYP2C19, CYP3A4, CYP2D6; and by the determination of the limited area under the curve from the capillary blood samples taken 2-3 and 6Â h after cocktail administration for CYP2C19 and P-gp. Two follow-up visits will take place between 25 and 40Â days and 50-70Â days after inclusion. They include assessment of efficacy, tolerance and observance. Eleven french centres are involved in recruitment, expected to be completed within approximately 2Â years with 205 patients. Metabolic ratios are determined in Geneva, Switzerland.
By showing an association between drug metabolism and VLX concentrations, efficacy and tolerance, there is a hope that testing drug metabolism pathways with a phenotypical approach would help physicians in selecting and dosing antidepressants. The MARVEL study will provide an important contribution to increasing the knowledge of VLX variability and in optimizing the use of methods of personalized therapy in psychiatric settings.
ClinicalTrials.gov NCT02590185 (10/27/2015). This study is currently recruiting participants
The impact of socioeconomic and phenotypic traits on self-perception of ethnicity in Latin America
Self-perception of ethnicity is a complex social trait shaped by both, biological and non-biological factors. We developed a comprehensive analysis of ethnic self-perception (ESP) on a large sample of Latin American mestizos from five countries, differing in age, socio-economic and education context, external phenotypic attributes and genetic background. We measured the correlation of ESP against genomic ancestry, and the influence of physical appearance, socio-economic context, and education on the distortion observed between both. Here we show that genomic ancestry is correlated to aspects of physical appearance, which in turn affect the individual ethnic self-perceived ancestry. Also, we observe that, besides the significant correlation among genomic ancestry and ESP, specific physical or socio-economic attributes have a strong impact on self-perception. In addition, the distortion among ESP and genomic ancestry differs across age ranks/countries, probably suggesting the underlying effect of past public policies regarding identity. Our results indicate that individualsâ own ideas about its origins should be taken with caution, especially in aspects of modern life, including access to work, social policies, and public health key decisions such as drug administration, therapy design, and clinical trials, among others
Comparing nuclear power trajectories in Germany and the UK: from âregimes' to âdemocraciesâ in sociotechnical transitions and Discontinuities
This paper focuses on arguably the single most striking contrast in contemporary major energy politics in Europe (and even the developed world as a whole): the starkly differing civil nuclear policies of Germany and the UK. Germany is seeking entirely to phase out nuclear power by 2022. Yet the UK advocates a ânuclear renaissanceâ, promoting the most ambitious new nuclear construction programme in Western Europe.Here,this paper poses a simple yet quite fundamental question: what are the particular divergent conditions most strongly implicated in the contrasting developments in these two countries. With nuclear playing such an iconic role in historical discussions over technological continuity and transformation, answering this may assist in wider understandings of sociotechnical incumbency and discontinuity in the burgeoning field ofâsustainability transitionsâ. To this end, an âabductiveâ approach is taken: deploying nine potentially relevant criteria for understanding the different directions pursued in Germany and the UK. Together constituted by 30 parameters spanning literatures related to socio-technical regimes in general as well as nuclear technology in particular, the criteria are divided into those that are âinternalâ and âexternalâ to the âfocal regime configurationâ of nuclear power and associated âchallenger technologiesâ like renewables.
It is âinternalâ criteria that are emphasised in conventional sociotechnical regime theory, with âexternalâ criteria relatively less well explored. Asking under each criterion whether attempted discontinuation of nuclear power would be more likely in Germany or the UK, a clear picture emerges. âInternalâ criteria suggest attempted nuclear discontinuation should be more likely in the UK than in Germanyâ the reverse of what is occurring.
âExternalâ criteria are more aligned with observed dynamics âespecially those relating to military nuclear commitments and broader âqualities of democracyâ. Despite many differences of framing concerning exactly what constitutes âdemocracyâ, a rich political science literature on this point is unanimous in characterising Germany more positively than the UK. Although based only on a single case,a potentially important question is nonetheless raised as to whether sociotechnical regime theory might usefully give greater attention to the general importance of various aspects of democracy in constituting conditions for significant technological discontinuities and transformations. If so, the policy implications are significant. A number of important areas are identified for future research, including the roles of diverse understandings and specific aspects of democracy and the particular relevance of military nuclear commitmentsâ whose under-discussion in civil nuclear policy literatures raises its own questions of democratic accountability
The NUMEN heavy ion multidetector for a complementary approach to the neutrinoless double beta decay
Neutrinos are so far the most elusive known particles, and in the last decades many sophisticated experiments have been set up in order to clarify several questions about their intrinsic nature, in particular their masses, mass hierarchy, intrinsic nature of Majorana or Dirac particles. Evidence of the Neutrinoless Double-Beta Decay (NDBD) would prove that neutrinos are Majorana particles, thus improving the understanding of the universe itself. Besides the search for several large underground experiments for the direct experimental detection of NDBD, the NUMEN experiment proposes the investigation of a nuclear mechanism strongly linked to this decay: the Double Charge Exchange reactions (DCE). As such reactions share with the NDBD the same initial and final nuclear states, they could shed light on the determination of the Nuclear Matrix Elements (NMEs), which play a relevant role in the decay. The physics of DCE is described elsewhere in this issue, while the focus of this paper will be on the challenging experimental apparatus currently under construction in order to fulfil the requirements of the NUMEN experiment. The overall structure of the technological improvement to the cyclotron, along with the newly developed detection systems required for tracking and identifying the reaction products and their final excitation level are described
Field test of quantum key distribution in the Tokyo QKD Network
A novel secure communication network with quantum key distribution in a
metropolitan area is reported. Different QKD schemes are integrated to
demonstrate secure TV conferencing over a distance of 45km, stable long-term
operation, and application to secure mobile phones.Comment: 21 pages, 19 figure
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