595 research outputs found
Risco Cardiovascular em Doentes com Infecção por VÃrus da Imunodeficiência Humana
O aumento do risco cardiovascular é considerada uma importante complicação da infecção Infecção por VÃrus da Imunodeficiência Humana (VIH) e da terapêutica anti-retroviral (TARV). À disfunção endotelial caracterÃstica do processo inflamatório crónico desencadeado pela infecção retroviral, associa-se a disfunção metabólica induzida pela terapêutica, predispondo, em conjunto, para a aterogénese precoce. O reconhecimento deste aumento de risco cardiovascular permite-nos elaborar estratégias de prevenção e optimização terapêutica que passam pelo uso criterioso de hipolipemiantes e modificação da TARV, consoante a avaliação do risco cardiovascular global de cada doente
Soil–Atmosphere Exchange of Nitrous Oxide, Nitric Oxide, Methane, and Carbon Dioxide in Logged and Undisturbed Forest in the Tapajos National Forest, Brazil
Selective logging is an extensive land use in the Brazilian Amazon region. The soil–atmosphere fluxes of nitrous oxide (N2O), nitric oxide (NO), methane (CH4), and carbon dioxide (CO2) are studied on two soil types (clay Oxisol and sandy loam Ultisol) over two years (2000–01) in both undisturbed forest and forest recently logged using reduced impact forest management in the Tapajos National Forest, near Santarem, Para, Brazil. In undisturbed forest, annual soil–atmosphere fluxes of N2O (mean ± standard error) were 7.9 ± 0.7 and 7.0 ± 0.6 ng N cm−2 h−1 for the Oxisol and 1.7 ± 0.1 and 1.6 ± 0.3 ng N cm−2 h−1 for the Ultisol for 2000 and 2001, respectively. The annual fluxes of NO from undisturbed forest soil in 2001 were 9.0 ± 2.8 ng N cm−2 h−1 for the Oxisol and 8.8 ± 5.0 ng N cm−2 h−1 for the Ultisol. Consumption of CH4 from the atmosphere dominated over production on undisturbed forest soils. Fluxes averaged −0.3 ± 0.2 and −0.1 ± 0.9 mg CH4 m−2 day−1 on the Oxisol and −1.0 ± 0.2 and −0.9 ± 0.3 mg CH4 m−2 day−1 on the Ultisol for years 2000 and 2001. For CO2 in 2001, the annual fluxes averaged 3.6 ± 0.4 μmol m−2 s−1 on the Oxisol and 4.9 ± 1.1 μmol m−2 s−1 on the Ultisol. We measured fluxes over one year each from two recently logged forests on the Oxisol in 2000 and on the Ultisol in 2001. Sampling in logged areas was stratified from greatest to least ground disturbance covering log decks, skid trails, tree-fall gaps, and forest matrix. Areas of strong soil compaction, especially the skid trails and logging decks, were prone to significantly greater emissions of N2O, NO, and especially CH4. In the case of CH4, estimated annual emissions from decks reached extremely high rates of 531 ± 419 and 98 ± 41 mg CH4 m−2 day−1, for Oxisol and Ultisol sites, respectively, comparable to wetland emissions in the region. We calculated excess fluxes from logged areas by subtraction of a background forest matrix or undisturbed forest flux and adjusted these fluxes for the proportional area of ground disturbance. Our calculations suggest that selective logging increases emissions of N2O and NO from 30% to 350% depending upon conditions. While undisturbed forest was a CH4 sink, logged forest tended to emit methane at moderate rates. Soil–atmosphere CO2 fluxes were only slightly affected by logging. The regional effects of logging cannot be simply extrapolated based upon one site. We studied sites where reduced impact harvest management was used while in typical conventional logging ground damage is twice as great. Even so, our results indicate that for N2O, NO, and CH4, logging disturbance may be as important for regional budgets of these gases as other extensive land-use changes in the Amazon such as the conversion of forest to cattle pasture
Vestibular rehabilitation in elderly patients with benign paroxysmal positional vertigo
The Benign Paroxysmal Positional Vertigo (BPPV) is a vestibular disorder where the patients complain brief moments of vertigo and/or present postural instability, caused by a brusque change in the cephalic or body movement. AIM: The objective of the present study is certificate the benefit of the vestibular rehabilitation in elderly people with Benign Paroxysmal Positional Vertigo. STUDY DESIGN: Clinical prospective. MATERIAL AND METHOD: Sixteen patients with BPPV were thread with extract of Ginkgo-biloba (40mg of 12/12h) during 30 days. Eight patients (the Experimental Group) were submitted to vestibular rehabilitation and the other called Control Group, didn't perform any kind of exercises. In order to perform the evaluation of the benefit we used the Scale of Activity of Daily Life and Vestibular Disorders by Kohen and Kimball, and used the t-student test to statistical analysis. CONCLUSION: The vestibular rehabilitation in group showed benefit in the treatment in the Experimental Group; the Scale of Activity of Daily Life and Vestibular Disorders, was an important tool for the qualitative evaluation in our rehabilitation proposal and the vestibular rehabilitation in group showed as an excellent therapeutic strategy.A Vertigem Posicional ParoxÃstica Benigna (VPPB) é um distúrbio vestibular no qual os pacientes relatam breves momentos de vertigem e/ou leve instabilidade postural, ocasionados por uma mudança brusca na movimentação cefálica ou corporal. OBJETIVO: Verificar o benefÃcio da reabilitação vestibular, realizada em grupo, em pacientes idosos portadores de VPPB. FORMA DE ESTUDO: ClÃnico prospectivo. MATERIAL E MÉTODO: Foram selecionados aleatoriamente 16 pacientes portadores de VPPB, todos medicados com extrato de Gingko-biloba (40mg de 12/12h) durante 30 dias. Oito deles, que formaram o Grupo Experimental, além do medicamento, foram submetidos à reabilitação vestibular e oito compuseram o Grupo Controle que não realizaram nenhum tipo de exercÃcio. Para avaliação do benefÃcio aplicamos a Escala de Atividades de Vida Diária e Desordens Vestibulares proposta por Cohen e Kimball. Para a análise estatÃstica utilizamos o teste t-student. CONCLUSÃO: Nossos resultados apontaram benefÃcio promovido pela reabilitação vestibular em grupo no tratamento de idosos portadores de VPPB; a avaliação qualitativa mostrou-se instrumento importante para a avaliação de benefÃcio para o tratamento proposto; e a reabilitação vestibular em grupo mostrou ser uma excelente estratégia terapêutica.UNIBANUMESPUNIFESP-EPMSanta Casa de São Paulo Faculdade de Ciências MédicasUNIFESP, EPMSciEL
Topological Superconductor from the Quantum Hall Phase: Effective Field Theory Description
We derive low-energy effective field theories for the quantum anomalous Hall
and topological superconducting phases. The quantum Hall phase is realized in
terms of free fermions with nonrelativistic dispersion relation, possessing a
global symmetry. We couple this symmetry with a background gauge field
and compute the effective action by integrating out the gapped fermions. In
spite of the fact that the corresponding Dirac operator governing the dynamics
of the original fermions is nonrelativistic, the leading contribution in the
effective action is a usual Abelian Chern-Simons term. The proximity to
a conventional superconductor induces a pairing potential in the quantum Hall
state, favoring the formation of Cooper pairs. When the pairing is strong
enough, it drives the system to a topological superconducting phase, hosting
Majorana fermions. Even though the continuum symmetry is broken down to
a one, we can forge fictitious symmetries that enable us
to derive the effective action for the topological superconducting phase, also
given by a Chern-Simons theory. To eliminate spurious states coming from the
artificial symmetry enlargement, we demand that the fields in the effective
action are instead of gauge fields. In the case we have to
sum over the bundles in the partition function, which projects
out the states that are not invariants. The corresponding edge
theory is the orbifold, which contains Majorana fermions in
its operator content.Comment: 40 pages, 5 figures, journal versio
Luttinger liquid superlattices
We calculate the correlation functions and the DC conductivity of Luttinger
liquid superlattices, modeled by a repeated pattern of interacting and free
Luttinger liquids. In a specific realization, where the interacting subsystem
is a Hubbard chain, the system exhibits a rich phase diagram with four
different phases: two metals and two compressible insulators. In general, we
find that the effective low energy description amalgamates features of both
types of liquids in proportion to their spatial extent, suggesting the
interesting possibility of `engineered' Luttinger liquids.Comment: RevTeX, 5 pages, 3 figure
Pengenalan dan Pencegahan Kenakalan Remaja (Adult Delicuency) melalui Psikoedukasi Keluarga
Kenakalan remaja adalah kecenderungan remaja untuk melakukan tindakan yang melanggar aturan yang dapat mengakibatkan kerugian dan kerusakan baik terhadap dirinya sendiri maupun orang lain. Melalui keluarga psikoedukasi dapat dilaksanakan, psikoedukasi keluarga merupakan salah satu bentuk intervensi yang dapat diberikan kepada keluarga yang mempunyai anggota keluarga dengan masalah kesehatan fisik yang berdampak pada mental emosional keluarga hingga menimbulkan munculnnya masalah psikososial. Tujuan utama dari terapi psikoedukasi keluarga ini adalah untuk memberikan informasi tentang kesehatan mental. Hasil pengabdian masyarakat menunjukkan bahwa sesudah penyuluhan, para orang tua terutama ibu – ibu menjadi bertambah wawasannya kemudian mengerti akan kenakalan remaja mulai dari pengertian, tanda – tanda, hingga cara mengatasinya
Characterization Of Multiscroll Attractors Using Lyapunov Exponents And Lagrangian Coherent Structures.
The present work aims to apply a recently proposed method for estimating Lyapunov exponents to characterize-with the aid of the metric entropy and the fractal dimension-the degree of information and the topological structure associated with multiscroll attractors. In particular, the employed methodology offers the possibility of obtaining the whole Lyapunov spectrum directly from the state equations without employing any linearization procedure or time series-based analysis. As a main result, the predictability and the complexity associated with the phase trajectory were quantified as the number of scrolls are progressively increased for a particular piecewise linear model. In general, it is shown here that the trajectory tends to increase its complexity and unpredictability following an exponential behaviour with the addition of scrolls towards to an upper bound limit, except for some degenerated situations where a non-uniform grid of scrolls is attained. Moreover, the approach employed here also provides an easy way for estimating the finite time Lyapunov exponents of the dynamics and, consequently, the Lagrangian coherent structures for the vector field. These structures are particularly important to understand the stretching/folding behaviour underlying the chaotic multiscroll structure and can provide a better insight of phase space partition and exploration as new scrolls are progressively added to the attractor.2302310
The broad-line type Ic SN 2020bvc: signatures of an off-axis gamma-ray burst afterglow
Long-duration gamma-ray bursts (GRBs) are almost unequivocally associated
with very energetic, broad-lined supernovae (SNe) of Type Ic-BL. While the
gamma-ray emission is emitted in narrow jets, the SN emits radiation
isotropically. Therefore, some SN Ic-BL not associated with GRBs have been
hypothesized to arise from events with inner engines such as off-axis GRBs or
choked jets. Here we present observations of the nearby ( Mpc) SN
2020bvc (ASAS-SN 20bs) which support this scenario. \textit{Swift} UVOT
observations reveal an early decline (up to two days after explosion) while
optical spectra classify it as a SN Ic-BL with very high expansion velocities
( 70,000 km/s), similar to that found for the jet-cocoon emission in
SN 2017iuk associated with GRB 171205A. Moreover, \textit{Swift} X-Ray
Telescope and \textit{CXO} X-ray Observatory detected X-ray emission only three
days after the SN and decaying onwards, which can be ascribed to an afterglow
component. Cocoon and X-ray emission are both signatures of jet-powered GRBs.
In the case of SN 2020bvc, we find that the jet is off axis (by 23
degrees), as also indicated by the lack of early ( day) X-ray
emission which explains why no coincident GRB was detected promptly or in
archival data. These observations suggest that SN 2020bvc is the first orphan
GRB detected through its associated SN emission.Comment: 9 pages, 6 figures, 5 tables. Accepted for publication in A&
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