Nuclear magnetic resonance measurements reveal the origin of the Debye process in monohydroxy alcohols

Monohydroxy alcohols show a structural relaxation and at longer time scales a Debye-type dielectric peak. From spin-lattice relaxation experiments using different nuclear probes an intermediate, slower-than-structural dynamics is identified for n-butanol. Based on these findings and on diffusion measurements, a model of self-restructuring, transient chains is proposed. The model is demonstrated to explain consistently the so far puzzling observations made for this class of hydrogen-bonded glass forming liquids.Comment: 4 pages, 4 figure

Produção de abelhas rainha européias (Apis mellifera), utilizando diferentes métodos de manejo em Captain Cook, Havai, EUA.

Objetivou-se verificar a influencia do uso de diferentes métodos de manejo nas colmeias recria, na aceitação de larvas para produção de abelhas rainha (Apis melífera ligustica). O trabalho foi conduzido durante o mês de agosto de 2008, na Hawaiian Queen CO, cidade de Captain Cook, estado do Havaí, EUA. Foi utilizado o método proposto por Doolittle (1899), utilizando-se cúpulas de acrílico. Os tratamentos foram: T1- colmeia recria com rainha composta por um ninho, tela excluidora e sobreninho (recria); T2- colmeia Recria com rainha composta por ninho, sobreninho 1, tela excluidora e sobreninho 2 (recria); T3- Introdução das larvas transferidas para ambiente com abelhas operárias órfãs e transferência para uma colmeia recria com rainha composta por um ninho, tela excluidora e sobreninho (recria); T4- Introdução das larvas transferidas para ambiente com abelhas operárias órfãs e transferência para uma colmeia recria com rainha composta por um ninho, sobreninho, tela excluidora e sobreninho (recria). Após execução do teste da normalidade de Shapiro-Wilk, foi executado o teste t para amostras independentes e Mann-Whitney. Verificou-se significância ao nível de 5% de probabilidade entre os tratamentos, ou seja, os tratamentos 1, 3 e 4 mostraram-se mais eficientes para aceitação das larvas e produção de rainhas

Influência da adubação na produção e eficiência da nodulação de leguminosas anuais de estação fria.

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Plastic Deformation of 2D Crumpled Wires

When a single long piece of elastic wire is injected trough channels into a confining two-dimensional cavity, a complex structure of hierarchical loops is formed. In the limit of maximum packing density, these structures are described by several scaling laws. In this paper it is investigated this packing process but using plastic wires which give origin to completely irreversible structures of different morphology. In particular, it is studied experimentally the plastic deformation from circular to oblate configurations of crumpled wires, obtained by the application of an axial strain. Among other things, it is shown that in spite of plasticity, irreversibility, and very large deformations, scaling is still observed.Comment: 5 pages, 6 figure

Avaliação de híbridos de mangueira no Semiárido brasileiro.

O objetivo foi de aproveitar as taxas de hibridação natural estimadas para a cultura. Os híbridos gerados foram cultivados no Campo Experimental de Mandacaru, localizado no município de Juazeiro, Bahia, e pertencente à Embrapa Semiárido

Fruit yield and quality of Palmer mango trees under different irrigation systems.

Mango production has been having a great economical expression in the Brazilian agriculture. However, the economic crisis and increased competitiveness of the international market required improvements in the crop efficiency for its sustainability. In this context, the objective of this work was to evaluate the effect of different irrigation system on the physiology and fruit yield and quality of Palmer mango trees in the semiarid conditions of the Lower Middle São Francisco Valley, Brazil. The experiment was carried out at the Agranvil Farm, in Petrolina, state of Pernambuco, Brazil, with harvests in July 2013 and October 2014. A randomized block statistical design was used, with four treatments replicated in 5 blocks, during two production cycles. The treatments consisted of four irrigation systems: one micro sprinkler under the plant canopy (MSPC); drip system with two lateral lines per plant row (DSLL); one micro sprinkler between plants (MSBP); and ring-shaped drip system around the plants (RSDS). All treatments provided a flow rate of 56 L h-1 plant-1. The physiological characteristics evaluated were: photosynthesis, stomatal conductance, leaf transpiration, and leaf temperature. Fruit yield, quantity, mean weight, volume, soluble solid content, titratable acidity (TA), density, and pulp firmness were evaluated after the harvest. The evaluated treatments presented significant differences for the physiological variables. The treatment DSLL provided higher number of fruits and fruit yield, and the treatment MSBP provided the lowest results for these variables

Caracterização física e físico-química de acessos de mangueira do Banco de Germoplasma da Embrapa Semiárido.

O presente trabalho teve como objetivo caracterizar acessos de mangueira, baseando-se em atributos físicos e físico-químicos, visando ao fortalecimento do programa de melhoramento genético da cultura desenvolvido na Embrapa Semiárido

Clemastine/tamoxifen hybrids as easily accessible antileishmanial drug leads

A library of hybrid molecules is developed based on the common chemical features shared by clemastine and tamoxifen both of which are well known for their antileishmanial activities. In the initial screening against Leishmania major and L. amazonensis promastigotes, as well as cytotoxicity assays using HepG2 cells, several hybrids showed submicromolar activity against the parasite and no toxicity against human cells. The compounds with an EC50 10 were further characterized against intracellular amastigotes as well as promastigotes of species that cause both visceral and cutaneous leishmaniasis, such as L. infantum and L. braziliensis, respectively. These sequential screenings revealed the high pan-activity of this class of molecules against these species, with several compounds displaying an EC50 ≤ 2 μM against both promastigotes and intracellular amastigotes. Two of them were identified as the potential templates for lead optimization of this series having shown the highest activities against all species in both stages of parasite. The present findings can serve as a good starting point in the search for novel antileishmanial compounds that are easy to access and highly active