395 research outputs found
Inflation from Supersymmetric Quantum Cosmology
We derive a special scalar field potential using the anisotropic Bianchi type
I cosmological model from canonical quantum cosmology under determined
conditions in the evolution to anisotropic variables . In the
process, we obtain a family of potentials that has been introduced by hand in
the literature to explain cosmological data. Considering supersymmetric quantum
cosmology, this family is scanned, fixing the exponential potential as more
viable in the inflation scenario .Comment: 14 pages, latex2e, To appear in Phys. Rev.
The closed primaries versus the top-two primary
The top-two primary recently approved in states like Washington, California, and Alaska eliminates the closed
party primaries and creates instead a single ballot in which the first and second place winners pass to the general
election. We compare the electoral consequences of the top-two primary with those of the closed primaries. We
present a model where each primary procedure induce a sequential game with three stages: candidate-entry
stage, primary election, and general election. We analyze the equilibria of these games and show that the top-two
primary contributes to political moderation and may increase the number of swing states.Financial assistance from Ministerio de Ciencia e Innovación under project ECO2011-29355 and Junta de AndalucÃa under
project SEJ5980 is gratefully acknowledged
Noncommutivity and Scalar Field Cosmology
In this work we extend and apply a previous proposal to study noncommutative
cosmology to the FRW cosmological background coupled to a scalar field, this is
done in classical and quantum scenarios. In both cases noncommutativity is
introduced in the gravitational field as well as in the scalar field through a
deformation of minisuperspace and are able to find exact solutions. Finally,
the effects of noncommutativity on the classical evolution are analyzed.Comment: 4 Pages, 2 figures, Revtex
On the Effects of a Workplace Fitness Program upon Pain Perception: a Case Study Encompassing Office Workers in a Portuguese Context
INTRODUCTION Office workers share several behavioural patterns: they work seated without moving for long times, they use only a few specific muscles of their arms, wrists and hands, and they keep an overall poor body posture. These working patterns generate musculoskeletal disorders, and produce discomfort or pain. Implementation of a work fitness program is thus a low-cost strategy to reduce/prevent body pain derived from work. The aim of this study was to test the benefits of a workplace fitness program, specifically applied to an administrative department of a Portuguese enterprise. Recall that this type of primary prevention level of musculoskeletal disorders has been seldom applied in Portugal, so this research effort materialized an important contribution to overcome such a gap. METHODS The participants in this study were office workers (n = 29 in the study group, and n = 21 in the control group)-who consistently had reported pain mostly on their back side (neck, posterior back, and dorsal and lumbar zones), wrists and posterior legs. The workplace fitness program consisted of three sessions per week during an 8-month period, with 15 min per session; emphasis was on stretching exercises for the body regions most affected by workers' pain perception. Each participant was requested to point out the injured region, as well as the intensity of pain felt, by using a visual analogue scale. Statistical analyses of the perceived pain data from control and study groups resort to non-parametric hypothesis tests. RESULTS There was a strong evidence that the workplace fitness program applied was effective in reducing workers' pain perception for their posterior back, dorsal and lumbar zones, and for their right wrist (P < 0.05). CONCLUSIONS These results generated are rather promising, so they may efficiently serve as an example for other enterprises in that country-while raising awareness on the important issue of quality of life at the workplace.info:eu-repo/semantics/publishedVersio
Molecular mechanisms beyond glucose transport in diabetes-related male infertility
Diabetes mellitus (DM) is one of the greatest public health threats in modern societies. Although during a few years it was suggested that DM had no significant effect in male reproductive function, this view has been challenged in recent years. The increasing incidence of DM worldwide will inevitably result in a higher prevalence of this pathology in men of reproductive age and subfertility or infertility associated with DM is expected to dramatically rise in upcoming years. From a clinical perspective, the evaluation of semen parameters, as well as spermatozoa deoxyribonucleic acid (DNA) integrity, are often studied due to their direct implications in natural and assisted conception. Nevertheless, recent studies based on the molecular mechanisms beyond glucose transport in testicular cells provide new insights in DM-induced alterations in male reproductive health. Testicular cells have their own glucose sensing machinery that react to hormonal fluctuations and have several mechanisms to counteract hyper- and hypoglycemic events. Moreover, the metabolic cooperation between testicular cells is crucial for normal spermatogenesis. Sertoli cells (SCs), which are the main components of blood–testis barrier, are not only responsible for the physical support of germ cells but also for lactate production that is then metabolized by the developing germ cells. Any alteration in this tied metabolic cooperation may have a dramatic consequence in male fertility potential. Therefore, we present an overview of the clinical significance of DM in the male reproductive health with emphasis on the molecular mechanisms beyond glucose fluctuation and transport in testicular cells
Bioadhesive properties of Gantrez nanoparticles
Bioadhesive nanoparticles have been proposed as carriers for the oral delivery of poorly available drugs and facilitate the use of this route. This work summarises some experiments describing the bioadhesive potential of Gantrez nanoparticles fluorescently labeled with rhodamine B isothiocyanate. The adhesive potential of Gantrez was found to be stronger when folded as nanoparticles than in the solubilised form. Conventional nanoparticles displayed a tropism for the upper areas of the gastrointestinal tract, with a maximum of adhesion 30 min post-administration and a decrease in the adhered fraction along the time depending on the given dose. The cross-linkage of nanoparticles with increasing amounts of 1,3-diaminopropane stabilised the resulting carriers and prolonged their half-life in an aqueous environment; although, the adhesive capacity of nanoparticles, the intensity and the relative duration of the adhesive interactions within the gut as a function of the cross-linking degree. Finally, nanoparticles were coated with either gelatin or albumin. In the first case, the presence of gelatin dramatically decreased the initial capacity of these carriers to interact with the gut mucosa and the intensity of these phenomenons. In the latter, bovine serum albumin coated nanoparticles (BSA-NP) showed an important tropism for the stomach mucosa without further significant distribution to other parts of the gut mucosa
The Juniperus flaccida-J. poblana complex revisited: insights from molecular and oil analysis
Analysis of nrDNA, petN-psbM, trnS-trnG, trnD-trnT, and trnF-trnL revealed that J. flaccida is diverse, but quite separated from J. poblana and J. aff. poblana from Nayarit by at least 10 Mutational events (MEs, SNPs + indels), and is actually a bit closer to J. standleyi (8 MEs). A divergent J. poblana from Oaxaca is merely 2 MEs distant from the Nayarit trees. The J. poblana samples from the type locality (Amozoc, Pue.) vary by only 1 ME among samples. Leaf oils, on the other hand, show to the Nayarit juniper quite differentiated from other J. poblana. In addition, the habit (large trees with a strong central axis with branchlets long, pendulous and very planate) and habitat of the Nayarit trees support the recognition of it as a different taxon closely related to J. poblana. However, additional evidence is needed in order to resolve its taxonomic status
Iso-spectral potential and inflationary quantum cosmology
Using the factorization approach of quantum mechanics, we obtain a family of
isospectral scalar potentials for power law inflationary cosmology. The
construction is based on a scattering Wheeler-DeWitt solution. These
iso-spectrals have new features, they give a mechanism to end inflation, as
well as the possibility to have new inflationary epochs. The procedure can be
extended to other cosmological models.Comment: 14 pages, 5 figure
Supersymmetric minisuperspace with non-vanishing fermion number
The Lagrangean of supergravity is dimensionally reduced to one
(time-like) dimension assuming spatial homogeneity of any Bianchi type within
class A of the classification of Ellis and McCallum. The algebra of the
supersymmetry generators, the Lorentz generators, the diffeomorphism generators
and the Hamiltonian generator is determined and found to close. In contrast to
earlier work, infinitely many physical states with non-vanishing even fermion
number are found to exist in these models, indicating that minisuperspace
models in supergravity may be just as useful as in pure gravity.Comment: 4 page
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