756 research outputs found
First-order framework and domain-wall/brane-cosmology correspondence
AbstractWe address the possibility of finding domain wall solutions from cosmological solutions in brane cosmology. We find first-order equations for corresponding cosmology/domain wall solutions induced on 3-branes. The quadratic term of energy density in the induced Friedmann equation plays a non-standard role and we discuss the way the standard cosmological and domain wall models are recovered as the brane tension becomes large and show how they can be described by four-dimensional supergravity action in such a limit. Finally, we show that gravity on the 3-brane is locally localized as one moves away from the two-dimensional domain walls living on the brane
Monte Carlo study of the critical temperature for the planar rotator model with nonmagnetic impurities
We performed Monte Carlo simulations to calculate the
Berezinskii-Kosterlitz-Thouless (BKT) temperature for the
two-dimensional planar rotator model in the presence of nonmagnetic impurity
concentration . As expected, our calculation shows that the BKT
temperature decreases as the spin vacancies increase. There is a critical
dilution at which . The effective interaction
between a vortex-antivortex pair and a static nonmagnetic impurity is studied
analytically. A simple phenomenological argument based on the pair-impurity
interaction is proposed to justify the simulations.Comment: 5 pages, 5 figures, Revetex fil
Preterm preeclampsia and timing of delivery: a systematic literature review
sem informaçãoIntroduction Preeclampsia, a multifactorial disease with pathophysiology not yet fully understood, is a major cause of maternal and perinatal morbidity and mortality, especially when preterm. The diagnosis is performed when there is an association between3911499499sem informaçãosem informaçãosem informaçã
Vortex behavior near a spin vacancy in 2D XY-magnets
The dynamical behavior of anisotropic two dimensional Heisenberg models is
still a matter of controversy. The existence of a central peak at all
temperatures and a rich structure of magnon peaks are not yet understood. It
seems that the central peaks are related, in some way, to structures like
vortices. In order to contribute to the discussion of the dynamical behavior of
the model we use Monte Carlo and spin dynamics simulations as well analytical
calculations to study the behavior of vortices in the presence of nonmagnetic
impurities. Our simulations show that vortices are attracted and trapped by the
impurities. Using this result we show that if we suppose that vortices are not
very much disturbed by the presence of the impurities, then they work as an
attractive potential to the vortices explaining the observed behavior in our
simulations.Comment: 4 pages, 6 figure
3D black holes on a 2-brane in 4D Minkowski space
We investigate three-dimensional black hole solutions in the realm of pure
and new massive gravity in 2+1 dimensions induced on a 2-brane embedded in a
flat four-dimensional spacetime. There is no cosmological constant neither on
the brane nor on the four-dimensional bulk. Only gravitational fields are
turned on and we indeed find vacuum solutions as black holes in 2+1 dimensions
even in the absence of any cosmological solution. There is a crossover scale
that controls how far the three- or four-dimensional gravity manifests on the
2-brane. Our solutions also indicate that local BTZ and SdS_3 solutions can
flow to local four-dimensional Schwarzschild like black holes, as one probes
from small to large distances, which is clearly a higher dimensional
manifestation on the 2-brane. This is similar to the DGP scenario where the
effects of extra dimensions for large probed distances along the brane
manifest.Comment: 10 pages, 5 figures, to appear in PL
Pregnancy In Women Undergoing Hemodialysis: Case Series In A Southeast Brazilian Reference Center [gestação Em Mulheres Em Tratamento HemodialĂtico: SĂ©rie De Casos Em Um Centro De ReferĂȘncia Do Sudeste Do Brasil]
PURPOSE: To describe maternal and neonatal outcomes in pregnant women undergoing hemodialysis in a referral center in Brazilian Southeast side. METHODS: Retrospective and descriptive study, with chart review of all pregnancies undergoing hemodialysis that were followed-up at an outpatient clinic of high- risk prenatal care in Southeast Brazil. RESULTS: Among the 16 women identified, 2 were excluded due to follow-up loss. In 14 women described, hypertension was the most frequent cause of chronic renal failure (half of cases). The majority (71.4%) had performed hemodialysis treatment for more than one year and all of them underwent 5 to 6 hemodialysis sessions per week. Eleven participants had chronic hypertension, 1 of which was also diabetic, and 6 of them were smokers. Regarding pregnancy complications, 1 of the hypertensive women developed malignant hypertension (with fetal growth restriction and preterm delivery at 29 weeks), 2 had acute pulmonary edema and 2 had abruption placenta. The mode of delivery was cesarean section in 9 women (64.3%). All neonates had Apgar score at five minutes above 7. CONCLUSIONS: To improve perinatal and maternal outcomes of women undergoing hemodialysis, it is important to ensure multidisciplinary approach in referral center, strict control of serum urea, hemoglobin and maternal blood pressure, as well as close monitoring of fetal well-being and maternal morbidities. Another important strategy is suitable guidance for contraception in these women.37159Bramham, K., Lightstone, L., Pre-pregnancy counseling for women with chronic kidney disease (2012) J Nephrol, 25 (4), pp. 450-459Hou, S., Pregnancy in chronic renal insufficiency and end-stage renal disease (1999) Am J Kidney Dis, 33 (2), pp. 235-252Shemin, D., Dialysis in pregnant women with chronic kidney disease (2003) Semin Dial, 16 (5), pp. 379-383Pipili, C., Grapsa, E., Koutsobasili, A., Sorvinou, P., Poirazlar, E., Kiosses, D., Pregnancy in dialysis-dependent women--the importance of frequent dialysis and collaborative care: A case report (2011) Hemodial Int, 15 (3), pp. 306-311Podymow, T., August, P., Akbari, A., Management of renal disease in pregnancy (2010) Obstet Gynecol Clin North Am, 37 (2), pp. 195-210Siviero, P., Machado, C.J., Cherchiglia, M.L., Chronic kidney failure by means of multiple causes of death in Brazil (2014) Cad SaĂșde Coletiva, 22 (1), pp. 75-85Furaz-Czerpak, K.R., FernĂĄndez-JuĂĄrez, G., Moreno-De La Higuera, M.A., Corchete-Prats, E., Puente-GarcĂa, A., MartĂn-HernĂĄndez, R., Pregnancy in women on chronic dialysis: A review (2012) Nefrologia, 32 (3), pp. 287-294Hou, S.H., Pregnancy in women on haemodialysis and peritoneal dialysis (1994) Baillieres Clin Obstet Gynaecol, 8 (2), pp. 481-500Chao, A.S., Huang, J.Y., Lien, R., Kung, F.T., Chen, P.J., Hsieh, P.C., Pregnancy in women who undergo long-term hemodialysis (2002) Am J Obstet Gynecol, 187 (1), pp. 152-156Reddy, S.S., Holley, J.L., Management of the pregnant chronic dialysis patient (2007) Adv Chronic Kidney Dis, 14 (2), pp. 146-155Piccoli, G.B., Cabiddu, G., Daidone, G., Guzzo, G., Maxia, S., Ciniglio, I., The children of dialysis: Live-born babies from on-dialysis mothers in Italy--an epidemiological perspective comparing dialysis, kidney transplantation and the overall population (2014) Nephrol Dial Transplant, 29 (8), pp. 1578-1586Shahir, A.K., Briggs, N., Katsoulis, J., Levidiotis, V., An observational outcomes study from 1966-2008, examining pregnancy and neonatal outcomes from dialysed women using data from the ANZDATA Registry (2013) Nephrology (Carlton), 18 (4), pp. 276-284Silva, G.B., Jr., Monteiro, F.A., Mota, R.M., Paiva, J.G., Correia, J.W., Bezerra Filho, J.G., Acute kidney injury requiring dialysis in obstetric patients: A series of 55 cases in Brazil (2009) Arch Gynecol Obstet, 279 (2), pp. 131-137Castellano, G., Losappio, V., Gesualdo, L., Update on pregnancy in chronic kidney disease (2011) Kidney Blood Press Res, 34 (4), pp. 253-260Hladunewich, M., Hercz, A.E., Keunen, J., Chan, C., Pierratos, A., Pregnancy in end stage renal disease (2011) Semin Dial, 24 (6), pp. 634-639Espinoza, F., Romeo, R., Ursu, M., Tapia, A., Vukusich, A., Pregnancy during dialysis: Experience in six patients (2013) Rev Med Chil, 141 (8), pp. 1003-1009Hladunewich, M.A., Hou, S., Odutayo, A., Cornelis, T., Pierratos, A., Goldstein, M., Intensive hemodialysis associates with improved pregnancy outcomes: A Canadian and United States cohort comparison (2014) J am Soc Nephrol, 25 (5), pp. 1103-110
ĂRICO GOBBI: RESGATANDO A MEMĂRIA DE UM ESCULTOR RIOGRANDINO ATRAVĂS DA ANĂLISE E DIAGNĂSTICO DE SUAS OBRAS COMO PATRIMĂNIO CULTURAL
O presente trabalho de pesquisa versarĂĄ sobre o escultor riograndino Ărico Gobbi e tem por objetivo diagnosticar e inventariar o acervo de obras deixado pelo artista. A coleção de Gobbi encontra-se boa parte em sua galeria de arte; sĂŁo bustos de polĂticos, filĂłsofos, pessoas conhecidas nacionalmente, medalhĂ”es, fotos, trofĂ©us, esculturas em vĂĄrios tamanhos e condecoraçÔes que recebeu durante sua vida. Seu acervo externo estĂĄ exposto em praças pĂșblicas da cidade e a mais conhecida de suas esculturas Ă© a estĂĄtua MĂŁe IemanjĂĄ, que localiza-se na praia do Cassino; sua coleção conta com mais de 100 obras. A preservação da galeria e das obras deixadas pelo o artista fica sob a responsabilidade do filho Edisom Gobbi ; as obras em lugares pĂșblicos estĂŁo sob a responsabilidade da prefeitura de Rio Grande. O escultor deixou uma herança cultural ao povo riograndino, a qual deverĂĄ ser divulgada e trabalhada sob os aspectos culturais, como patrimĂŽnio e memĂłria da cidade do Rio Grande
Physico-chemical aspects of grape juices produced in the region of Campanha Gaucha, RS, Brazil (Southern Brazil)
The Campanha Gaucha region, southern Brazil, has received significant investments in Viticulture during the last decades, especially for the production of quality wines. However, implementing the production of American and hybrid grapes in this region constitutes and opportunity to supply the increasing demand of the grape juice market in Brazil. Juices of two varieties, âBordĂŽâ and âConcordâ, from two locations, Dom Pedrito and Santana do Livramento, were analysed in terms of the following physico-chemical aspects: total city, volatile acidity, density, pH, soluble solids content, color intensity, and hue. âBordĂŽâ juices presented higher total acidity and did not differ in relation to location. Higher volatile acidity was found in âConcordâ juice from Santana do Livramento. Higher pH was found in the variety âConcordâ and in the location Dom Pedrito. For this same location, the âConcordâ grape juices showed higher soluble solids values. Color intensity was higher in Santana do Livramento. Color hue was higher in Dom Pedrito. Both variety and location impacted significantly on physico-chemical aspects of grape juices, although all the grapes were produced within the Campanha Gaucha region
Unconventional spin fluctuations in the hexagonal antiferromagnet YMnO
We used inelastic neutron scattering to show that well below its N\'{e}el
temperature, , the two-dimensional (2D) XY nearly-triangular
antiferromagnet YMnO has a prominent {\it central peak} associated with
2D antiferromagnetic fluctuations with a characteristic life time of 0.55(5)
ps, coexisting with the conventional long-lived spin-waves. Existence of the
two time scales suggests competition between the N\'{e}el phase favored by weak
interplane interactions, and the Kosterlitz-Thouless phase intrinsic to the 2D
XY spin system.Comment: 4pages, 5figure
Low Temperature Static and Dynamic Behavior of the Two-Dimensional Easy-Axis Heisenberg Model
We apply the self-consistent harmonic approximation (SCHA) to study static
and dynamic properties of the two-dimensional classical Heisenberg model with
easy-axis anisotropy. The static properties obtained are magnetization and spin
wave energy as functions of temperature, and the critical temperature as a
function of the easy-axis anisotropy. We also calculate the dynamic correlation
functions using the SCHA renormalized spin wave energy. Our analytical results,
for both static properties and dynamic correlation functions, are compared to
numerical simulation data combining cluster-Monte Carlo algorithms and Spin
Dynamics. The comparison allows us to conclude that far below the transition
temperature, where the SCHA is valid, spin waves are responsible for all
relevant features observed in the numerical simulation data; topological
excitations do not seem to contribute appreciably. For temperatures closer to
the transition temperature, there are differences between the dynamic
correlation functions from SCHA theory and Spin Dynamics; these may be due to
the presence of domain walls and solitons.Comment: 12 pages, 14 figure
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