Density Waves in Layered Systems with Fermionic Polar Molecules

A layered system of two-dimensional planes containing fermionic polar molecules can potentially realize a number of exotic quantum many-body states. Among the predictions, are density-wave instabilities driven by the anisotropic part of the dipole-dipole interaction in a single layer. However, in typical multilayer setups it is reasonable to expect that the onset and properties of a density-wave are modified by adjacent layers. Here we show that this is indeed the case. For multiple layers the critical strength for the density-wave instability decreases with the number of layers. The effect depends on density and is more pronounced in the low density regime. The lowest solution of the instability corresponds to the density waves in the different layers being in-phase, whereas higher solutions have one or several adjancet layers that are out of phase. The parameter regime needed to explore this instability is within reach of current experiments.Comment: 7 pages, 4 figures. Final version in EPJD, EuroQUAM special issue "Cold Quantum Matter - Achievements and Prospects

Bound Chains of Tilted Dipoles in Layered Systems

Ultracold polar molecules in multilayered systems have been experimentally realized very recently. While experiments study these systems almost exclusively through their chemical reactivity, the outlook for creating and manipulating exotic few- and many-body physics in dipolar systems is fascinating. Here we concentrate on few-body states in a multilayered setup. We exploit the geometry of the interlayer potential to calculate the two- and three-body chains with one molecule in each layer. The focus is on dipoles that are aligned at some angle with respect to the layer planes by means of an external eletric field. The binding energy and the spatial structure of the bound states are studied in several different ways using analytical approaches. The results are compared to stochastic variational calculations and very good agreement is found. We conclude that approximations based on harmonic oscillator potentials are accurate even for tilted dipoles when the geometry of the potential landscape is taken into account.Comment: 10 pages, 6 figures. Submitted to Few-body Systems special issue on Critical Stability, revised versio

Zika virus infection in pregnancy: a protocol for the joint analysis of the prospective cohort studies of the ZIKAlliance, ZikaPLAN and ZIKAction consortia

INTRODUCTION: Zika virus (ZIKV) infection in pregnancy has been associated with microcephaly and severe neurological damage to the fetus. Our aim is to document the risks of adverse pregnancy and birth outcomes and the prevalence of laboratory markers of congenital infection in deliveries to women experiencing ZIKV infection during pregnancy, using data from European Commission-funded prospective cohort studies in 20 centres in 11 countries across Latin America and the Caribbean. METHODS AND ANALYSIS: We will carry out a centre-by-centre analysis of the risks of adverse pregnancy and birth outcomes, comparing women with confirmed and suspected ZIKV infection in pregnancy to those with no evidence of infection in pregnancy. We will document the proportion of deliveries in which laboratory markers of congenital infection were present. Finally, we will investigate the associations of trimester of maternal infection in pregnancy, presence or absence of maternal symptoms of acute ZIKV infection and previous flavivirus infections with adverse outcomes and with markers of congenital infection. Centre-specific estimates will be pooled using a two-stage approach. ETHICS AND DISSEMINATION: Ethical approval was obtained at each centre. Findings will be presented at international conferences and published in peer-reviewed open access journals and discussed with local public health officials and representatives of the national Ministries of Health, Pan American Health Organization and WHO involved with ZIKV prevention and control activities

Is arterial stiffness in HIV-infected individuals associated with HIV-related factors?

We investigated the association between pulse wave velocity (PWV) and HIV infection, antiretroviral treatment-related characteristics, viral load, immune status, and metabolic changes in a cross-sectional study nested in a cohort of HIV/AIDS patients who have been followed for metabolic and cardiovascular changes since 2007. The study included patients recruited from the cohort (N = 261) and a comparison group (N = 82) of uninfected individuals, all enrolled from April to November 2009. Aortic stiffness was estimated using the carotid-femoral PWV (Complior-Artech, Paris, France). The groups were similar with respect to age, metabolic syndrome, diabetes mellitus, Framingham score, and use of antihypertensive and hypolipidemic medications. Hypertension was more frequent among the controls. Individuals with HIV had higher triglyceride, glucose and HDL cholesterol levels. Among individuals with HIV/AIDS, those with a nadir CD4+ T-cell count <200 cells/mm³ had a higher PWV (P = 0.01). There was no statistically significant difference when subjects were stratified by gender. Heart rate, age, male gender, and blood pressure were independently correlated with PWV. Nadir CD4+ T-cell count did not remain in the final model. There was no significance difference in PWV between HIV-infected individuals and uninfected controls. PWV was correlated with age, gender, and blood pressure across the entire population and among those infected with HIV. We recommend cohort studies to further explore the association between inflammation related to HIV infection and/or immune reconstitution and antiretroviral use and PWV

INTRODUÇÃO À AGRICULTURA DE PRECISÃO: CONCEITOS E VANTAGENS INTRODUCTION THE PRECISION FARMING: CONCEPTS AND ADVANTAGES

A revisão bibliográfica apresentada é uma síntese de diversos autores, os quais proporcionam uma introdução à agricultura de precisão, através de conceitos básicos e vantagens que o sistema oferece, demonstrando que não é somente uma colhedora automotriz com um sistema de posicionamento global. A agricultura de precisão pode ser considerada como um amplo conceito, englobando tecnologias e novos conhecimentos de informática, eletrônica, geoprocessamento entre outros. Este conceito incorpora um grande número de conhecimentos científicos novos e alta tecnologia, apresentando ao produtor novos termos, conceitos, equipamentos e tecnologias.<br>The presented bibliographical revision is a synthesis of several authors, which provide an introduction to the precision farming, through basic concepts and advantages that the system offers, demonstrating that it is not only a combine harvester with a global positioning system. The precision farming can be considered as a wide concept, including technologies and new computer science knowledge, electronics, geoprocessing among others. This concept incorporates a great number of new scientific knowledge and high technology, presenting to the farmer, new concepts, equipments and technologies

Desempenho produtivo de ovinos alimentados com dietas à base de feno de gramíneas tropicais Performance of sheep fed tropical grass hay based diets

O estudo foi realizado com o objetivo de avaliar o desempenho produtivo e o consumo de matéria seca e nutrientes em ovinos confinados e alimentados com dietas à base de fenos das gramíneas: capim-elefante, capim-buffel, capim-milhã-roxa e capim-urochloa. Foram utilizados 32 animais da raça Santa Inês (16 machos e 16 femeas) com peso médio de 26,5 kg. Utilizou-se o delineamento inteiramente casualizado, com quatro repetições, sendo cada repetição composta por dois animais. Os animais apresentaram respostas semelhantes para todos os parâmetros avaliados. O ganho de peso foi semelhante entre as dietas estudadas, sendo o valor médio para ganho de peso de 95 g/animal/dia. Não foram observadas diferenças nos consumos de matéria seca e fibra detergente neutro entre as várias dietas estudadas. As dietas à base de feno de milhã-roxa permitiram maior consumo de proteína bruta. Concluiu-se que os fenos avaliados podem ser utilizados na alimentação de ovinos.<br>A study was conducted to evaluate the performance and the dry matter and nutrients intake in feedlot sheep fed diets with different levels of hray from tropical grasses: elephantgrass, buffelgrass, "milhã-roxa" and "urochloa"grass. Santa Inês hairy sheep (16 males and 16 females; average weight = 26,5 kg). A completely randomized design, with four replicates and two animals per experimental unit, was used. Males and females showed the same response to all treatments. Weight gain was similar for all diets, with an average of 95 g/animal/day. Dry matter and neutral detergent fiber intake were not different among all treatments. However, diets with "milhã-rôxa" hay were associated to the highest crude protein intake. It was concluded that all types of hay can be used for feedlot sheep

Taxonomia do gênero Euploca Nutt. (Heliotropiaceae) no Brasil Taxonomy of the genus Euploca Nutt. [Heliotropiaceae] in Brazil

O presente trabalho trata do estudo taxonômico do gênero Euploca (Heliotropiaceae) no Brasil, sendo registradas 17 espécies. É apresentada chave para o reconhecimento, descrições, ilustrações e comentários, além de dados de distribuição, habitat, floração e frutificação para as espécies.<br>This work deals with a taxonomic study of the genus Euploca (Heliotropiaceae) in Brazil; seventeen species are recorded. A keyfor identification, descriptions, illustrations and comments, besides distribution, habitat, flowering and fruiting data for the species are presented