1,306 research outputs found
Increased sympathetic tone and hypothalamic–pituitary–adrenal (HPA) axis activation impact in metabolic parameters from hypertensive rats
Increased activity of the sympathetic nervous system (SNS) may play an important role in the development of hypertension and in adiposity disorders. We aimed to investigate the influence of increased sympathetic tone and hypothalamic–pituitary–adrenal (HPA) axis activation in metabolic parameters by evaluating the morphometry of isolated adipocytes from different fat pads and energy consumption. Serum levels of catecholamines, HPA hormones, T3 and adipokines were measured in 15-weeks-old Wistar (WIS), Wistar-Kyoto (WKY), Spontaneously Hypertensive Rats (SHR) and WIS treated with NG-nitro-L-arginine methyl ester (L-NAME). L-NAME and SHR showed a reduced adiposity when compared to their controls, which may be related to higher concentrations of T3. However, SHR presented the most evident lipodystrophy, presenting significant changes in the morphometry from isolated adipocytes and the production of adipokines. Thus, our study suggests that endocrine changes in hypertension models may highlight possible therapeutic targets in the treatment of metabolic changes associated with hypertension
5D gravitational waves from complexified black rings
In this paper we construct and briefly study the 5D time-dependent solutions
of general relativity obtained via double analytic continuation of the black
hole (Myers-Perry) and of the black ring solutions with a double
(Pomeransky-Senkov) and a single rotation (Emparan-Reall). The new solutions
take the form of a generalized Einstein-Rosen cosmology representing
gravitational waves propagating in a closed universe. In this context the
rotation parameters of the rings can be interpreted as the extra wave
polarizations, while it is interesting to state that the waves obtained from
Myers-Perry Black holes exhibit an extra boost-rotational symmetry in higher
dimensions which signals their better behavior at null infinity. The analogue
to the C-energy is analyzed.Comment: 18 pages, 4 figures. References added, introduction and conclusions
are amended, some issues related to singularity structure and symmetries are
discussed. Matches the print version to appear in JHE
Universality and exactness of Schrodinger geometries in string and M-theory
We propose an organizing principle for classifying and constructing
Schrodinger-invariant solutions within string theory and M-theory, based on the
idea that such solutions represent nonlinear completions of linearized vector
and graviton Kaluza-Klein excitations of AdS compactifications. A crucial
simplification, derived from the symmetry of AdS, is that the nonlinearities
appear only quadratically. Accordingly, every AdS vacuum admits infinite
families of Schrodinger deformations parameterized by the dynamical exponent z.
We exhibit the ease of finding these solutions by presenting three new
constructions: two from M5 branes, both wrapped and extended, and one from the
D1-D5 (and S-dual F1-NS5) system. From the boundary perspective, perturbing a
CFT by a null vector operator can lead to nonzero beta-functions for spin-2
operators; however, symmetry restricts them to be at most quadratic in
couplings. This point of view also allows us to easily prove nonrenormalization
theorems: for any Sch(z) solution of two-derivative supergravity constructed in
the above manner, z is uncorrected to all orders in higher derivative
corrections if the deforming KK mode lies in a short multiplet of an AdS
supergroup. Furthermore, we find infinite classes of 1/4 BPS solutions with
4-,5- and 7-dimensional Schrodinger symmetry that are exact.Comment: 31 pages, plus appendices; v2, minor corrections, added refs, slight
change in interpretation in section 2.3, new Schrodinger and Lifshitz
solutions included; v3, clarifications in sections 2 and 3 regarding
existence of solutions and multi-trace operator
Non-Supersymmetric String Theory
A class of non-supersymmetric string backgrounds can be constructed using
twists that involve space-time fermion parity. We propose a non-perturbative
definition of string theory in these backgrounds via gauge theories with
supersymmetry softly broken by twisted boundary conditions. The perturbative
string spectrum is reproduced, and qualitative effects of the interactions are
discussed. Along the way, we find an interesting mechanism for inflation. The
end state of closed string tachyon condensation is a highly excited state in
the gauge theory which, in all likelihood, does not have a geometric
interpretation.Comment: 35 pages, 2 figures; revision adds a computation of the relevant
orbifold state
Rectal mucosal prolapse syndrome as an unusual gastrointestinal manifestation of Sjögren's syndrome: a case report
Platinum–Vanadium Oxide Nanotube Hybrids
The present contribution reports on the features of platinum-based systems supported on vanadium oxide nanotubes. The synthesis of nanotubes was carried out using a commercial vanadium pentoxide via hydrothermal route. The nanostructured hybrid materials were prepared by wet impregnation using two different platinum precursors. The formation of platinum nanoparticles was evaluated by applying distinct reduction procedures. All nanostructured samples were essentially analysed by X-ray diffraction and transmission electron microscopy. After reduction, transmission electron microscopy also made it possible to estimate particle size distribution and mean diameter calculations. It could be seen that all reduction procedures did not affect the nanostructure of the supports and that the formation of metallic nanoparticles is quite efficient with an indistinct distribution along the nanotubes. Nevertheless, the reduction procedure determined the diameter, dispersion and shape of the metallic particles. It could be concluded that the use of H2PtCl6 is more suitable and that the use of hydrogen as reducing agent leads to a nanomaterial with unagglomerated round-shaped metallic particles with mean size of 6–7 nm
Fauna used in popular medicine in Northeast Brazil
<p>Abstract</p> <p>Background</p> <p>Animal-based remedies constitute an integral part of Brazilian Traditional Medicine. Due to its long history, zootherapy has in fact become an integral part of folk medicine both in rural and urban areas of the country. In this paper we summarize current knowledge on zootherapeutic practices in Northeast of Brazil, based on information compiled from ethnobiological scientific literature.</p> <p>Methods</p> <p>In order to examine the diversity of animals used in traditional medicine in Northeast of Brazil, all available references or reports of folk remedies based on animals sources were examined. 34 sources were analyzed. Only taxa that could be identified to species level were included in assessment of medicinal animal species. Scientific names provided in publications were updated.</p> <p>Results</p> <p>The review revealed that at least 250 animal species (178 vertebrates and 72 invertebrates) are used for medicinal purposes in Northeast of Brazil. The inventoried species comprise 10 taxonomic categories and belong to 141 Families. The groups with the greatest number of species were fishes (n = 58), mammals (n = 47) and reptiles (n = 37). The zootherapeutical products are used for the treatment of different illnesses. The most widely treated condition were asthma, rheumatism and sore throat, conditions, which had a wide variety of animals to treat them with. Many animals were used for the treatment of multiple ailments. Beyond the use for treating human diseases, zootherapeutical resources are also used in ethnoveterinary medicine</p> <p>Conclusion</p> <p>The number of medicinal species catalogued was quite expressive and demonstrate the importance of zootherapy as alternative therapeutic in Northeast of Brazil. Although widely diffused throughout Brazil, zootherapeutic practices remain virtually unstudied. There is an urgent need to examine the ecological, cultural, social, and public health implications associated with fauna usage, including a full inventory of the animal species used for medicinal purposes and the socio-cultural context associated with their consumption.</p
Formyl Peptide Receptor as a Novel Therapeutic Target for Anxiety-Related Disorders
Formyl peptide receptors (FPR) belong to a family of sensors of the immune system that detect microbe-associated molecules and inform various cellular and sensorial mechanisms to the presence of pathogens in the host. Here we demonstrate that Fpr2/3-deficient mice show a distinct profile of behaviour characterised by reduced anxiety in the marble burying and light-dark box paradigms, increased exploratory behaviour in an open-field, together with superior performance on a novel object recognition test. Pharmacological blockade with a formyl peptide receptor antagonist, Boc2, in wild type mice reproduced most of the behavioural changes observed in the Fpr2/3(-/-) mice, including a significant improvement in novel object discrimination and reduced anxiety in a light/dark shuttle test. These effects were associated with reduced FPR signalling in the gut as shown by the significant reduction in the levels of p-p38. Collectively, these findings suggest that homeostatic FPR signalling exerts a modulatory effect on anxiety-like behaviours. These findings thus suggest that therapies targeting FPRs may be a novel approach to ameliorate behavioural abnormalities present in neuropsychiatric disorders at the cognitive-emotional interface
Stationary Black Holes: Uniqueness and Beyond
The spectrum of known black-hole solutions to the stationary Einstein
equations has been steadily increasing, sometimes in unexpected ways. In
particular, it has turned out that not all black-hole-equilibrium
configurations are characterized by their mass, angular momentum and global
charges. Moreover, the high degree of symmetry displayed by vacuum and
electro-vacuum black-hole spacetimes ceases to exist in self-gravitating
non-linear field theories. This text aims to review some developments in the
subject and to discuss them in light of the uniqueness theorem for the
Einstein-Maxwell system.Comment: Major update of the original version by Markus Heusler from 1998.
Piotr T. Chru\'sciel and Jo\~ao Lopes Costa succeeded to this review's
authorship. Significantly restructured and updated all sections; changes are
too numerous to be usefully described here. The number of references
increased from 186 to 32
Positional Signaling and Expression of ENHANCER OF TRY AND CPC1 Are Tuned to Increase Root Hair Density in Response Phosphate Deficiency in Arabidopsis thaliana
Phosphate (Pi) deficiency induces a multitude of responses aimed at improving the acquisition of Pi, including an increased density of root hairs. To understand the mechanisms involved in Pi deficiency-induced alterations of the root hair phenotype in Arabidopsis (Arabidopsis thaliana), we analyzed the patterning and length of root epidermal cells under control and Pi-deficient conditions in wild-type plants and in four mutants defective in the expression of master regulators of cell fate, CAPRICE (CPC), ENHANCER OF TRY AND CPC 1 (ETC1), WEREWOLF (WER) and SCRAMBLED (SCM). From this analysis we deduced that the longitudinal cell length of root epidermal cells is dependent on the correct perception of a positional signal (‘cortical bias’) in both control and Pi-deficient plants; mutants defective in the receptor of the signal, SCM, produced short cells characteristic of root hair-forming cells (trichoblasts). Simulating the effect of cortical bias on the time-evolving probability of cell fate supports a scenario in which a compromised positional signal delays the time point at which non-hair cells opt out the default trichoblast pathway, resulting in short, trichoblast-like non-hair cells. Collectively, our data show that Pi-deficient plants increase root hair density by the formation of shorter cells, resulting in a higher frequency of hairs per unit root length, and additional trichoblast cell fate assignment via increased expression of ETC1
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