Expansion of a Bose-Einstein Condensate in an atomic waveguide

The expansion of a Bose-Einstein condensate in an atomic waveguide is analyzed. We study different regimes of expansion, and identify a transient regime between one-dimensional and three-dimensional dynamics, in which the properties of the condensate and its further expansion can be well explained by reducing the transversal dynamics to a two-level system. The relevance of this regime in current experiments is discussed.Comment: 4 pages, 3 figs, Accepted for publication in Phys. Rev.

Mean field effects in a trapped classical gas

In this article, we investigate mean field effects for a bosonic gas harmonically trapped above the transition temperature in the collisionless regime. We point out that those effects can play also a role in low dimensional system. Our treatment relies on the Boltzmann equation with the inclusion of the mean field term. The equilibrium state is first discussed. The dispersion relation for collective oscillations (monopole, quadrupole, dipole modes) is then derived. In particular, our treatment gives the frequency of the monopole mode in an isotropic and harmonic trap in the presence of mean field in all dimensions.Comment: 4 pages, no figure submitted to Phys. Rev.

Spatial distribution of the most abundant sea urchin populations on the southeast coast of São Paulo (Brazil)

Se investigó la variación espacial en la abundancia de Echinometra lucunter, Lytechinus variegatus y Arbacia lixula con respecto a cuatro escalas espaciales (105, 104, 103 y 102 m) y dos profundidades (0–3 y 3–8 m), a lo largo de 100 km del litoral de São Paulo (agosto a octubre de 1996). Echinometra lucunter fue la especie más abundante, prefiriendo los fondos más someros bajo el efecto del oleaje. Se identificó un gradiente en su abundancia, aumentando en dirección del suroeste al noreste. Arbacia lixula mostró el mismo gradiente, pero con una mayor abundancia en el sector más profundo. Ambas especies mostraron diferencias significativas a una escala espacial de centenares de metros y E. lucunter también a una escala de kilómetros. Lytechinus variegatus mostró un patrón en mosaico, siendo abundante en ciertos sitios. Las variaciones en la calidad del agua y en la heterogeneidad natural del hábitat podrían explicar de forma conjunta la distribución espacial de estas poblaciones.The spatial variability of Echinometra lucunter, Lytechinus variegatus and Arbacia lixula was studied in relation to four spatial scales (105, 104, 103 and 102 m) and two depths (0–3 and 3–8 m), along 100 km of the São Paulo coastline (August to October 1996). Echinometra lucunter was the most abundant species, with preference for shallow substrates subject to wave action. An abundance gradient was identified, increasing from southwest to northeast. Arbacia lixula showed the same pattern of spatial variation, but was more abundant in the deeper areas. Both species showed significant differences on a spatial scale of hundreds of meters, and E. lucunter also on a scale of kilometers. Lytechinus variegates presented a patchy distribution, being more abundant at certain sites. Variations in the water quality and natural heterogeneity of the habitat may explain the spatial distribution of these populations.El presente trabajo ha sido realizado gracias a dos becas INTERCAMPUS (1996–1997) concedidas por el Gobierno Español (Ministerio de Asuntos Exteriores) a PSJ para su estancia en el Laboratorio de Ecotoxicología (Brasil)

Contributo para a caracterização morfométrica da raça de abelhas melíferas (Apis mellifera iberiensis) da região norte de Portugal

A necessidade de aprofundar o conhecimento sobre a morfologia da abelha melífera portuguesa (Apis mellifera iberiensis) originou o presente estudo. A amostragem definiu-se com base no banco de amostras existentes no Laboratório de Patologia Apícola da ESA-IPB, relativas ao ano de 2015. Cada amostra foi constituída por cinco obreiras adultas conservadas pelo frio (-18 °C). Foram analisadas 124 amostras distribuídas por 16 concelhos (aproximadamente oito por concelho) pertencentes aos distritos de Bragança e Vila Real. As medições efetuadas em cada uma das obreiras foram: peso (PA), comprimento (CA) e largura (LA) do corpo; comprimento (CAA) e largura (LAA) da asa anterior; comprimento (CAP) e largura da asa posterior (LAP); comprimento do fêmur (CF), da tíbia (CT), do basitarso (CBT), do tarso (CTA) e da probóscide (CP) e a largura do basitarso (LBT). Para avaliação destas medidas utilizou-se uma balança analítica de precisão (0,01g) e um paquímetro eletrónico digital (0-100mm±0,02mm). As diferentes variáveis estudadas compararam-se por análise de variância (ANOVA), sendo o teste de Tukey-Kramer HSD utilizado para a comparação múltipla de médias. O peso médio das obreiras do concelho de Vila Pouca de Aguiar (0,123±0,018 g) foi mais elevado (p0,05) entre os concelhos estudados.info:eu-repo/semantics/publishedVersio

Models of electron transport in single layer graphene

The main features of the conductivity of doped single layer graphene are analyzed, and models for different scattering mechanisms are presented.Comment: 15 pages. Submitted to the Proceedings of the ULTI symposium on Quantum Phenomena and Devices at Low Temperatures, Espoo, Finland, to be published in the Journ. of Low. Temp. Phy

Water toxicity and cyto-genotoxicity biomarkers in the fish Oreochromis niloticus (Cichlidae)

Micronucleus (MN) and nuclear abnormalities (NA) tests were used as biomarkers in the fish Oreochromis niloticus from a polluted pond in winter, spring and summer. Samples of water column were taken aiming to evaluate physical-chemical parameters and acute toxicity to the microcrustacean Daphnia similis. The pond waters were toxic to D. similis in spring and winter, but this toxicity was not detected in summer. The pond waters presented low levels of dissolved oxygen in spring and summer; higher ammonia concentrations in winter, and high hardness and conductivity. Fish collected at the polluted pond exhibited higher rates of DNA damage, as indicated by increased rates of MN and NA in erythrocytes when compared to the negative control, which were associated to water toxicity and physical-chemical variable. Thus, this study shows that results of water toxicity tests and genotoxic biomarkers in fish may be associated and theses approaches may be used together for the water quality assessment.Keywords: fish, cyto-genotoxicity, pollution, ecotoxicology, water quality

In silico analysis of cytochrome p450 genes involved in the metabolism of diterpenes in Coffea.

Brazil is the largest world producer and exporter of coffee, being also the second largest consumer market. Among the main goals of coffee breeders, studies aiming the improvement of cup quality and plant tolerance to biotic and abiotic stresses have extreme importance. Beverage nutraceutical properties and plant defense mechanisms are directly linked to diterpenes present in the lipid fraction of coffee beans, such as cafestol (Caf ) and caveol (Cav). Many members of P 450 gene family are involved in plant secondary metabolism, including diterpenes synthesis. In order to depict biochemical and genetic aspects of diterpenes byosinthesis, we did an in silico characterization of p450 gene family in Coffea spp., and we also quantified Caf and Cav in coffee fruit tissues for further gene expression studies involving diterpens metabolism. Using keyword and Blast search, 1396 ESTs related to Cyt p450 were selected from the Brazilian Coffee Genome Project (http://www.lge.ibi. unicamp.br/cafe). After assembling, we observed 157 putative unigenes, distributed in 92 contigs and 65 singlets. The contigs were analyzed using BLAST X versus public sequences databases (GenBank and Harvest Coffea), confirming their identity to 91 Cyt P450 genes. Expression profiles were inferred by electronic Northern blot of all contigs, allowing the selection of 7 candidate genes for transcriptional analysis based in fruit cDNA library expression. Caf and Cav were measured using HPLC in two different fruit developmental stages: 90 DAF (Days After Flowering) vs 120 DAF and in fruits (120 DAF) treated with 2?M methyl Jasmonate (MJ). Fruits at 120 DAF had an increase of 42% in Cav and 19% in Caf levels in relation to 90DAF fruits. MJ treatment resulted in samples with an average increase of 18% of Cav and 35% of Caf. RNAs were extracted from these samples for future transcriptional analyses. This study establish a platform for expression analysis of cyt P450 candidate genes in RNA samples from tissues with contrasting accumulation of Cav and Caf. (Texte intégral

Schur functions and their realizations in the slice hyperholomorphic setting

we start the study of Schur analysis in the quaternionic setting using the theory of slice hyperholomorphic functions. The novelty of our approach is that slice hyperholomorphic functions allows to write realizations in terms of a suitable resolvent, the so called S-resolvent operator and to extend several results that hold in the complex case to the quaternionic case. We discuss reproducing kernels, positive definite functions in this setting and we show how they can be obtained in our setting using the extension operator and the slice regular product. We define Schur multipliers, and find their co-isometric realization in terms of the associated de Branges-Rovnyak space

Ground state and elementary excitations of single and binary Bose-Einstein condensates of trapped dipolar gases

We analyze the ground-state properties and the excitation spectrum of Bose-Einstein condensates of trapped dipolar particles. First, we consider the case of a single-component polarized dipolar gas. For this case we discuss the influence of the trapping geometry on the stability of the condensate as well as the effects of the dipole-dipole interaction on the excitation spectrum. We discuss also the ground state and excitations of a gas composed of two antiparallel dipolar components.Comment: 12 pages, 9 eps figures, final versio

Tourniquet use for civilian extremity hemorrhage: Systematic review of the literature [Uso de torniquete nas hemorragias de extremidades na população civil: Revisão sistemática da literatura]

Introduction: extremity tourniquet (TQ) use has increased in the civilian setting; the beneficial results observed in the military has influenced acceptance by EMS and bystanders. This review aimed to analyze extremity TQ types used in the civilian setting, injury site, indications, and complications. Methods: a systematic review was conducted based on original articles published in PubMed, Embase, and Cochrane following PRISMA guidelines from 2010 to 2019. Data extraction focused on extremity TQ use for hemorrhage control in the civilian setting, demographic data, study type and duration, mechanism of injury, indications for use, injury site, TQ type, TQ time, and complications. Results: of the 1384 articles identified, 14 were selected for review with a total of 3912 civilian victims with extremity hemorrhage and 3522 extremity TQ placements analyzed. The majority of TQs were applied to male (79%) patients, with blunt or penetrating trauma. Among the indications for TQ use were hemorrhagic shock, suspicion of vascular injuries, continued bleeding, and partial or complete traumatic amputations. Upper extremity application was the most common TQ application site (56%), nearly all applied to a single extremity (99%), and only 0, 6% required both upper and lower extremity applications. 80% of the applied TQs were commercial devices, and 20% improvised. Conclusions: TQ use in the civilian setting is associated with trauma-related injuries. Most are single-site TQs applied for the most part to male adults with upper extremity injury. Commercial TQs are more commonly employed, time in an urban setting is under 1 hour, with few complications described. Introdução: o uso de torniquete em extremidades (TQ) aumentou no ambiente civil; os resultados benéficos observados nas forças armadas influenciaram a aceitação por equipes de pré-hospitalar (PH) assim como pela população leiga. Esta revisão teve como objetivo analisar os tipos de TQ de extremidades usados em ambiente civil, local da lesão, indicações e complicações. Métodos: revisão sistemática foi conduzida com base em artigos originais publicados no PubMed, Embase e Cochrane seguindo as diretrizes do PRISMA de 2010 a 2019. Extração de dados focada no uso de TQ de extremidade para controle de hemorragia em ambiente civil, dados demográficos, tipo de estudo e duração, mecanismo de lesão, indicações de uso, local da lesão, tipo de TQ, tempo de TQ e complicações. Resultados: dos 1.384 artigos identificados, 14 foram selecionados para revisão com total de 3.912 vítimas civis com hemorragia nas extremidades e 3.522 colocações de extremidades TQ analisadas. A maioria foi aplicado em pacientes do sexo masculino (79%), com trauma contuso ou penetrante. Entre as indicações estavam choque hemorrágico, suspeita de lesões vasculares, sangramento contínuo e amputações traumáticas parciais ou completas. A aplicação na extremidade superior foi o local de aplicação mais comum (56%), quase todos aplicados a uma única extremidade (99%), e apenas 0, 6% requereram aplicações nas extremidades superior e inferior. 80% dos TQs aplicados eram dispositivos comerciais e 20% improvisados. Conclusões: o uso de TQ em ambientes civis está associado a traumas. Os TQs comerciais são mais utilizados, com tempo menor que uma hora de uso e poucas complicações