Rotating Dilaton Solutions in 2+1 Dimensions

We report a three parameter family of solutions for dilaton gravity in 2+1 dimensions with finite mass and finite angular momentum. These solutions are obtained by a compactification of vacuum solutions in 3+1 dimensions with cylindrical symmetry. One class of solutions corresponds to conical singularities and the other leads to curvature singularities.Comment: Accepted to be published in Gen. Rel. Grav., added reference

Tuning hole mobility in InP nanowires

Transport properties of holes in InP nanowires were calculated considering electron-phonon interaction via deformation potentials, the effect of temperature and strain fields. Using molecular dynamics, we simulate nanowire structures, LO-phonon energy renormalization and lifetime. The valence band ground state changes between light- and heavy-hole character, as the strain fields and the nanowire size are changed. Drastic changes in the mobility arise with the onset of resonance between the LO-phonons and the separation between valence subbands.Comment: 4 pages, 4 figure

Properties of Solutions in 2+1 Dimensions

We solve the Einstein equations for the 2+1 dimensions with and without scalar fields. We calculate the entropy, Hawking temperature and the emission probabilities for these cases. We also compute the Newman-Penrose coefficients for different solutions and compare them.Comment: 16 pages, 1 figures, PlainTeX, Dedicated to Prof. Yavuz Nutku on his 60th birthday. References adde

Composição da comunidade bacteriana do solo sob sistemas integrados na região norte de Mato Grosso.

Os sistemas integrados de produção agrícola estão sendo estudados como uma alternativa aos monocultivos tradicionais no intuíto de tornar a atividade agrícola sustentável, particulamente no estado do Mato Grosso. Entretanto, ainda não se conhece como essa atividade afeta as propriedades microbiológicas do solo. Assim, o objetivo deste trabalho foi avaliar e comparar os efeitos de sistemas integrados na composição da comunidade bacteriana do solo com diferentes monocultivos tendo como área referência uma mata nativa do bioma de transição Cerrado e Amazônia. O local de estudo está localizado na Embrapa Agrossilvipastoril no município de Sinop/MT e foram avaliados sete tratamentos (1-mata nativa, 2-lavoura, 3-pecuária, 4-eucalipto, 5-integração eucalipto lavoura (iEL), 6-integração eucalipto pecuária (iEP), 7-integração eucalipto lavoura pecuária (iELP)) dispostos em quatro blocos casualizados, os quais foram conduzidos segundo as recomendações agronômicas das espécies cultivadas. As amostras de solo foram coletadas nas épocas de chuva e estiagem em 2012 com o auxílio de trado holandês na profundidade de 0-10 cm, considerando 20 pontos aleatórios com caminhamento zigue-zague para fazer uma composta de cada tratamento. A extração de DNA total do solo foi realizada com o kit MoBio UltraClean? Soil DNA (MoBio Laboratories, Carlsbad, CA., EUA) conforme protocolo descrito pelo fabricante e sequenciado pela tecnologia Illumina (Illumina, Inc., CA, USA) com a plataforma MiSeq na Universidade da Florida (Gainesville, EUA). Por meio de ferramentas de bioinformática 2.957.127 sequencias do gene 16S rRNA com alta qualidade foram obtidas, sendo que 2.172.432 de OTUs (Operational Taxonomic Units) foram classificados para o domínio Bacteria, 3.564 Archaea e 262.994 não foram classificados. A composição bacteriana do solo com abundancia relativa ≥ 10 % a nível de filo apresentou três táxons, porém Firmicutes e Proteobacteria apresentaram padrão de comportamento de maior abundancia na estiagem em relação a chuva para mata nativa e iELP e para a lavoura o padrão foi o oposto . A nível de classe, dentre cinco filos apenas Actinobacteria variou o comportamento para iELP e mata nativa com menor abundância na estiagem e maior na chuva, tendo a lavoura o comportamento inverso e para Clostridia ocorreu o mesmo padrão porém ao contrário para os respectivos tratamentos. Analisando a diferença entre os tratamentos por meio da dissimiliradidade a nível de filo, corte de abundância relativa ≥ 0.05 % (18 filos na estiagem e 21 na chuva), o dendrograma baseado na distância euclidiana agrupou mata nativa e iELP como os mais semelhantes e lavoura o mais dissimilar dentre todos os tratamentos. Podemos concluir, que o sistema integrado eucalipto lavoura pecuária apresentou maior semelhança na sua composição bacteriana do solo com a da mata nativa em comparação com os demais tratamentos avaliados, como também manteve o padrão do comportamento da abundancia relativa parecido na época de estiagem, assim demonstrando indício de sustentabilidade

On the Nonlinear Stability of Asymptotically Anti-de Sitter Solutions

Despite the recent evidence that anti-de Sitter spacetime is nonlinearly unstable, we argue that many asymptotically anti-de Sitter solutions are nonlinearly stable. This includes geons, boson stars, and black holes. As part of our argument, we calculate the frequencies of long-lived gravitational quasinormal modes of AdS black holes in various dimensions. We also discuss a new class of asymptotically anti-de Sitter solutions describing noncoalescing black hole binaries.Comment: 26 pages. 5 figure

Myxobolus sp. (Myxozoa) in the circulating blood of Colossoma macropomum (Osteichthyes, Characidae).

Myxosporea parasitize many organs in fresh and saltwater fish. Species of the genus Myxobolus parasitizing the gills and other organs of the tambaqui Colossoma macropomum have been described. In the present study, blood smears were made from juvenile tambaqui and were stained with May Grunwald-Giemsa-Wright in order to identify myxozoan parasites. Out of a total of 36 fish examined, one specimen (2.7%) that was reared in a cage presented spores that were identified as M. colossomatis, whereas fish kept in 250 L tanks showed prevalence of 5.5%. This is the first report of M. colossomatis in the blood of farmed tambaqui in the Amazon region. These results indicate that myxozoan parasites should also be investigated in fish blood smears. Some myxosporean species may cause diseases in fish, and these species need to be identified so that adequate preventive sanitary control can be instituted

Podridão do colo (Sclerotium rolfsii Sacc.) em pimenta salada ou pimenta doce (Capsicum annum) no Estado do Amapá.

A cultura da pimenta salada é uma importante fonte de renda para o agricultor amapaense. É também conhecida como pimenta do cheiro ou pimenta doce, no Amapá. Em levantamentos efetuados nos diversos municípios do estado, através de um projeto em parceria entre o Centro de Pesquisa Agroflorestal do Amapá - Embrapa Amapá e o Instituto de Pesquisa Florestal do Amapá, verificou-se a ocorrência de um fungo de solo (Sclerotium rolfsii Sacc.) que ocasiona a murcha de plantas de pimenta salada, descrito pela primeira vez por Rolfs, em 1892, em tomateiros na Flórida, Estados Unidos e segundo Moraes (1982), tal fungo apresenta uma maior distribuição em regiões tropicais e subtropicais, onde a alta temperatura prevalece durante as estações chuvosas.bitstream/item/97385/1/CPAF-AP-2002-Podridao-colo.pd

A near-NHEK/CFT correspondence

We consider excitations around the recently introduced near-NHEK metric describing the near-horizon geometry of the near-extremal four-dimensional Kerr black hole. This geometry has a U(1)_L x U(1)_R isometry group which can be enhanced to a pair of commuting Virasoro algebras. We present boundary conditions for which the conserved charges of the corresponding asymptotic symmetries are well defined and non-vanishing and find the central charges c_L=12J/hbar and c_R=0 where J is the angular momentum of the black hole. Applying the Cardy formula reproduces the Bekenstein-Hawking entropy of the black hole. This suggests that the near-extremal Kerr black hole is holographically dual to a non-chiral two-dimensional conformal field theory.Comment: 11 pages, v2: references updated, adde

Charged C-metric with conformally coupled scalar field

We present a generalisation of the charged C-metric conformally coupled with a scalar field in the presence of a cosmological constant. The solution is asymptotically flat or a constant curvature spacetime. The spacetime metric has the geometry of a usual charged C-metric with cosmological constant, where the mass and charge are equal. When the cosmological constant is absent it is found that the scalar field only blows up at the angular pole of the event horizon. The presence of the cosmological constant can generically render the scalar field regular where the metric is regular, pushing the singularity beyond the event horizon. For certain cases of enhanced acceleration with a negative cosmological constant, the conical singularity disappears all together and the scalar field is everywhere regular. The black hole is then rather a black string with its event horizon extending all the way to asymptotic infinity and providing itself the necessary acceleration.Comment: regular article, no figures, typos corrected, to appear in Classical and Quantum Gravit

The Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System (CATT-BRAMS) ? Part 1: Model description and evaluation

International audienceWe introduce the Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System (CATT-BRAMS). CATT-BRAMS is an on-line transport model fully consistent with the simulated atmospheric dynamics. Emission sources from biomass burning and urban-industrial-vehicular activities for trace gases and aerosol particles are obtained from several published datasets and remote sensing information. The tracer and aerosol mass concentration prognostic includes the effects of sub-grid scale turbulence in the planetary boundary layer, convective transport by shallow and deep moist convection, wet and dry deposition, and plume rise associated with vegetation fires in addition to the grid scale transport. The radiation parameterization takes into account the interaction between aerosol particles and short and long wave radiation. The atmospheric model BRAMS is based on the Regional Atmospheric Modeling System (RAMS), with several improvements associated with cumulus convection representation, soil moisture initialization and surface scheme tuned for the tropics, among others. In this paper the CATT-BRAMS model is used to simulate carbon monoxide and particulate material (PM2.5) surface fluxes and atmospheric transport during the 2002 LBA field campaigns, conducted during the transition from the dry to wet season in the southwest Amazon Basin. Model evaluation is addressed with comparisons between model results and near surface, radiosonde and airborne measurements performed during the field campaign, as well as remote sensing derived products. We show the matching of emissions strengths to observed carbon monoxide in the LBA campaign. A relatively good comparison to the MOPITT data, in spite of the fact that MOPITT a priori assumptions imply several difficulties, is also obtained