14 research outputs found
A New Relativistic High Temperature Bose-Einstein Condensation
We discuss the properties of an ideal relativistic gas of events possessing
Bose-Einstein statistics. We find that the mass spectrum of such a system is
bounded by where is the usual chemical
potential, is an intrinsic dimensional scale parameter for the motion of an
event in space-time, and is an additional mass potential of the
ensemble. For the system including both particles and antiparticles, with
nonzero chemical potential the mass spectrum is shown to be bounded by
and a special type of high-temperature
Bose-Einstein condensation can occur. We study this Bose-Einstein condensation,
and show that it corresponds to a phase transition from the sector of
continuous relativistic mass distributions to a sector in which the boson mass
distribution becomes sharp at a definite mass This phenomenon
provides a mechanism for the mass distribution of the particles to be sharp at
some definite value.Comment: Latex, 22 page
Reprodução da piranha-amarela Serrasalmus spilopleura Kner, 1858, em lagos de várzea, Amazonas, Brasil
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Plasmid-mediated extended-spectrum beta-lactamase-producing strains of Enterobacteriaceae isolated from diabetes foot infections in a Brazilian diabetic center
We bacteriologically analyzed 156 species of Enterobacteriaceae, isolated from 138 patients with community-acquired diabetic foot ulcers, in a prospective study made at a diabetic center and at the Federal University of Ceará, Brazil, from March, 2000, to November, 2001.The samples were cultured using selective media, and identification, susceptibility tests and detection of plasmid-mediated-extended-spectrum-beta-lactamase (ESBL) producing strains were made with conventional and automated methods. The most frequently occurring pathogens were K. pneumoniae (21.2%), Morganella morganii (19.9%) and E. coli (15.4%). High resistance rates were noted for ampicillin, first generation cephalosporin, trimethoprim/sulfamethoxazole, tetracycline, amoxicillin-clavulanic acid and chloramphenicol. ESBL-producing strains were detected in 6% of the patients. Resistance among gram-negative bacteria has become increasingly common, even in community-acquired infections
Plasmid-mediated extended-spectrum beta-lactamase-producing strains of Enterobacteriaceae isolated from diabetes foot infections in a Brazilian diabetic center
We bacteriologically analyzed 156 species of Enterobacteriaceae, isolated from 138 patients with community-acquired diabetic foot ulcers, in a prospective study made at a diabetic center and at the Federal University of Ceará, Brazil, from March, 2000, to November, 2001.The samples were cultured using selective media, and identification, susceptibility tests and detection of plasmid-mediated-extended-spectrum-beta-lactamase (ESBL) producing strains were made with conventional and automated methods. The most frequently occurring pathogens were K. pneumoniae (21.2%), Morganella morganii (19.9%) and E. coli (15.4%). High resistance rates were noted for ampicillin, first generation cephalosporin, trimethoprim/sulfamethoxazole, tetracycline, amoxicillin-clavulanic acid and chloramphenicol. ESBL-producing strains were detected in 6% of the patients. Resistance among gram-negative bacteria has become increasingly common, even in community-acquired infections
O potencial do aruanã Osteoglossum bicirrhosum (Vandelli, 1829) (Osteoglossiformes, Osteoglosidae) para a criação em cativeiro The potential of arawana Osteoglossum bicirrhosum (Vandelli, 1829) (Osteoglossiformes, Osteoglosiidae) for the creation in captivity
O presente trabalho teve como objetivo identificar uma nova espécie para a criação em cativeiro na região amazônica, visando atender não somente a demanda do mercado local, mas os anseios de um mercado consumidor ávido por novos produtos de qualidade. Para tanto, foi utilizado como ponto de partida o banco de dados do Projeto Manejo dos Recursos Naturais Renováveis de 2001 a 2004. Fazendo uma ligação destes dados com os obtidos junto ao Núcleo de Recursos Pesqueiros do Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis e da Secretaria Especial de Aqüicultura e Pesca da Presidência da República/AM, possibilitou-se identificar o aruanã Osteoglossum bicirrhosum (Vandelli, 1829) como um pescado com potencial para a criação em cativeiro. Foram analisados ainda os valores de mercado e realizadas análises da composição centesimal e do rendimento de carcaça, que creditaram ao aruanã uma carne magra (0,08% de gordura) e protéica (15,19%), com um rendimento de 29,15 ± 1,48% de filé.<br>The present work had as objective to identify a new species for creation in captivity in the Amazon region, aiming not only the demand of the local market, but also a consuming market interested in new products and with quality. It was used as starting point the data base of the Projeto Manejo dos Recursos Naturais Renováveis of 2001 the 2004. Making a link of this data with the Nucleus of Resources the Fishing of the Brazilian Institute of the Environment and the Natural resources and the Special Secretariat of Aqüicultura and Fishing of the Presidency of the Republic/AM database, it was made possible to identify the arawana Osteoglossum bicirrhosum (Vandelli, 1829) as a fish with potential for the creation in captivity. Market values were analyzed and carried through analyses of the centesimal composition and the income of carcass, that they had credited the arawana a lean meat (0,08% of fat) and proteic (15,19%), with an meat yield of 29,15 ± 1,48% of filet
Alterações bioquímicas durante a embebição de sementes de catingueira (Caesalpinia pyramidalis Tul.)
Characterization of Tomato yellow spot virus, a novel tomato-infecting begomovirus in Brazil Caracterização do Tomato yellow spot virus, um novo begomovírus isolado de tomateiro no Brasil
The objective of this work was the biological and molecular characterization of a begomovirus detected in São Joaquim de Bicas, Minas Gerais, Brazil, named TGV-[Bi2], by determining its host range, complete nucleotide sequence and phylogenetic relationships with other begomoviruses. Biological characterization consisted of a host range study using either sap inoculation or particle bombardment as inoculation methods. The yellow spot virus can infect plants in Solanaceae and Amaranthaceae, including economically importat crops as sweet pepper, and weeds as Datura stramonium and Nicotiana silvestris. For the molecular characterization, the full-length genome (DNA-A and DNA-B) was amplified, cloned and completely sequenced. Sequence comparisons and phylogenetic analyses indicated that TGV-[Bi2] constitutes a novel begomovirus species named Tomato yellow spot virus (ToYSV), closely related to Sida mottle virus (SiMoV).<br>O objetivo deste trabalho foi a caracterização biológica e molecular de um begomovírus detectado em tomateiros em São Joaquim de Bicas, Minas Gerais, denominado TGV-[Bi2]. A caracterização biológica consistiu em teste de gama de hospedeiros, realizado por meio de inoculação via extrato foliar tamponado ou bombardeamento de partículas. O isolado TGV-[Bi2] infecta plantas das famílias Solanaceae e Amaranthaceae, inclusive espécies economicamente importantes como o pimentão, e algumas plantas daninhas como Datura stramonium e Nicotiana silvestris. A caracterização molecular consistiu na clonagem e seqüenciamento de seu genoma completo (DNA-A e DNA-B). A comparação de seqüências e análise filogenética indicaram que o TGV-[Bi2] constitui uma nova espécie de begomovírus, denominada Tomato yellow spot virus (ToYSV), filogeneticamente relacionado ao Sida mottle virus (SiMoV)