Atomic Bose-Einstein condensation with three-body interactions and collective excitations

The stability of a Bose-Einstein condensed state of trapped ultra-cold atoms is investigated under the assumption of an attractive two-body and a repulsive three-body interaction. The Ginzburg-Pitaevskii-Gross (GPG) nonlinear Schrodinger equation is extended to include an effective potential dependent on the square of the density and solved numerically for the s-wave. The lowest collective mode excitations are determined and their dependences on the number of atoms and on the strength of the three-body force are studied. The addition of three-body dynamics can allow the number of condensed atoms to increase considerably, even when the strength of the three-body force is very small compared with the strength of the two-body force. We study in detail the first-order liquid-gas phase transition for the condensed state, which can happen in a critical range of the effective three-body force parameter.

Collective Perspective on Advances in Dyson-Schwinger Equation QCD

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Self-bound droplet of Bose and Fermi atoms in one dimension: Collective properties in mean-field and Tonks-Girardeau regimes

We investigate a dilute mixture of bosons and spin-polarized fermions in one dimension. With an attractive Bose-Fermi scattering length the ground state is a self-bound droplet, i.e., a Bose-Fermi bright soliton where the Bose and Fermi clouds are superimposed. We find that the quantum fluctuations stabilize the Bose-Fermi soliton such that the one-dimensional bright soliton exists for any finite attractive Bose-Fermi scattering length. We study density profile and collective excitations of the atomic bright soliton showing that they depend on the bosonic regime involved: mean-field or Tonks-Girardeau.

DIFFERENT MEDIA, DIFFERENT TYPES OF COLLECTIVE WORK IN ONLINE CONTINUING TEACHER EDUCATION: WOULD YOU PASS THE PEN, PLEASE?

This paper presents some findings regarding the interaction between different computer interfaces and different types of collective work. We want to claim that design in online learning environments has a paramount role in the type of collaboration that happens among participants. In this paper, we report on data that illustrate how teachers can collaborate online in order to learn how to use geometry software in teaching activities. A virtual environment which allows that construction to be carried out collectively, even if the participants are not sharing a classroom, is the setting for the research presented in this paper.

The workload and plasma ion concentration in a training match session of high-goal (elite) polo ponies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Collective scattering of massive stars in higher order gravity

In the weak field approximation of higher order gravity theory a gravitational potential is described by a Newtonian plus a Yukawa-like term. This new term is used to explain some aspects of galactic dynamics, without considering dark matter. Its presence modifies the scattering probability of a massive intruder star and relaxation time of the stellar system.

Stabilizing an attractive Bose-Einstein condensate by driving a surface collective mode

Bose-Einstein condensates with attractive interatomic interactions undergo collective collapse beyond a critical number. We show theoretically that if the low-lying collective modes of the condensate are excited, the radial breathing mode further destabilizes the condensate. Remarkably, excitation of the quadrupolar surface mode causes the condensate to become more stable, imparting quasiangular momentum to it. A significantly larger number of atoms may then occupy the condensate. Efforts are under way for the experimental realization of these effects. ©2001 The American Physical Society.

Prevalence and reasons for tooth loss in a sample from a dental clinic in Brazil

Purpose. To evaluate the prevalence and reasons for teeth extractions in a sample from a dental clinic in Brazil. Methods. The prevalence of teeth mortality was analyzed by gender, age, tooth type and reasons for extraction on 800 teeth of 439 subjects, whose data was collected in clinical records in a convenience sample. Results. The groups with range from 35 to 44 years, 45 to 54 years and 55 to 64 years revealed significantly greater number of teeth extractions than other age groups (P < 0.0001). The anterior teeth loss increased significantly with aging, while the tooth mortality of premolar and molar were higher in younger people. The caries was the more prevalent reason for tooth mortality among young and adults up to 44 years old, while the periodontal disease was the main reason for extractions from 45 years old until range of 81 years (P < 0.0001). Conclusions. It can be suggested that some reasons for tooth loss were age-dependent, but the caries and the periodontal diseases were the main reasons for tooth mortality in this Brazilian sample. Copyright © 2012 Andréia Montandon et al.

Occurrence of mycobacteria in bovine milk samples from both individual and collective bulk tanks at farms and informal markets in the southeast region of Sao Paulo, Brazil

Background: Mycobacterium spp. is one of the most important species of zoonotic pathogens that can be transmitted from cattle to humans. The presence of these opportunistic, pathogenic bacteria in bovine milk has emerged as a public-health concern, especially among individuals who consume raw milk and related dairy products. To address this concern, the Brazilian control and eradication program focusing on bovine tuberculosis, was established in 2001. However, bovine tuberculosis continues to afflict approximately 1,3 percent of the cattle in Brazil. In the present study, 300 samples of milk from bovine herds, obtained from both individual and collective bulk tanks and informal points of sale, were cultured on Löwenstein-Jensen and Stonebrink media. Polymerase chain reaction (PCR)-based tests and restriction-enzyme pattern analysis were then performed on the colonies exhibiting phenotypes suggestive of Mycobacterium spp., which were characterized as acid-fast bacilli.Results: Of the 300 bovine milk samples that were processed, 24 were positively identified as Mycobacterium spp.Molecular identification detected 15 unique mycobacterial species: Mycobacterium bovis, M. gordonae, M. fortuitum, M. intracellulare, M. flavescens, M. duvalii, M. haemophilum, M. immunogenum, M. lentiflavum, M. mucogenicum, M. novocastrense, M. parafortuitum, M. smegmatis, M. terrae and M. vaccae. The isolation of bacteria from the various locations occurred in the following proportions: 9 percent of the individual bulk-tank samples, 7 percent of the collective bulk-tank samples and 8 percent of the informal-trade samples. No statistically significant difference was observed between the presence of Mycobacterium spp. in the three types of samples collected, the milk production profiles, the presence of veterinary assistance and the reported concerns about bovine tuberculosis prevention in the herds.Conclusion: The microbiological cultures associated with PCR-based identification tests are possible tools for the investigation of the presence of Mycobacterium spp. in milk samples. Using these methods, we found that the Brazilian population may be regularly exposed to mycobacteria by consuming raw bovine milk and related dairy products. These evidences reinforces the need to optimize quality programs of dairy products, to intensify the sanitary inspection of these products and the necessity of further studies on the presence of Mycobacterium spp. in milk and milk-based products. © 2013 Franco et al.; licensee BioMed Central Ltd.

Investigações acerca do uso da narrativa no teatro contemporâneo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Perspectivas para uma teoria geral dos novos direitos: uma leitura crítica sobre a biodiversidade e os conhecimentos tradicionais associados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Os estudos de Avery, Macleod e Mccarty e a idéia do DNA como responsável pela hereditariedade: interpretações historiográficas e apontamentos para o ensino de biologia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O paciente que busca atendimento odontológico na Faculdade de Odontologia de Araçatuba: seus motivos, seus anseios, suas expectativas e dificuldades

Pós-graduação em Odontologia Preventiva e Social - FOA