The Effect of Feed Supplementation and Sward Characteristics on the Ingestive Behaviour of Grazing Ewes

The objective of this study was to assess the effect of protein/energy supplementation and sward physical characteristics on grazing behaviour of lactating ewes grazing Italian ryegrass (Lolium multiflorum Lam.). The experiment was carried out in the spring of 1999 at the Universidade Federal de Santa Maria. The grazing behaviour was assessed in two periods: 2 and 3 September, and 8 and 9 October of 1999, using a group of twelve yearling ewes. Groups of four ewes were either supplemented (with 1% of the animals live weight) with soybean meal (protein source), with corn (energy source) or not supplemented. The experiment was carried out in a completely randomised block design with four replications. This experiment shows that grazing behaviour is more strongly affected by sward characteristics than by protein or energy supplementation

DyNetVis: a system for visualization of dynamic networks

The concept of networks has been important in the study of complex systems. In networks, links connect pairs of nodes forming complex structures. Studies have shown that networks not only contain structure but may also evolve in time. The addition of the temporal dimension adds complexity on the analysis and requests the development of innovative methods for the visualization of real-life networks. In this paper we introduce the Dynamic Network Visualization System (DyNetVis), a software tool for visualization of dynamic networks. The system provides several tools for user interaction and offers two coordinated visual layouts, named structural and temporal. Structural refers to standard network drawing techniques, in which a single snapshot of nodes and links are placed in a plane, whereas the temporal layout allows for simultaneously visualization of several temporal snapshots of the dynamic network. In addition, we also investigate two approaches for temporal layout visualization: (i) Recurrent Neighbors, a node ordering strategy that highlights frequent connections in time, and (ii) Temporal Activity Map (TAM), a layout technique with focus on nodes activity. We illustrate the applicability of the layouts and interaction functionalities provided by the system in two visual analysis case studies, demonstrating their advantages to improve the overall user experience on visualization and exploratory data analysis on dynamic networks

Properties of a new poly-ether-glycol copolymer.

Triblock copolymers are made of monomer segments, being the central part usually hydrophobic and the outer parts hydrophilic. By varying sizes, molecular weights and monomer types of the segments one obtains different final molecules, with different physico-chemical properties, which are directly related to the performance of the final product. Looking for new products to be used, among other possibilities, in biological applications, a new polymer (Figure 1) was synthesized by the Dow Chemical and studied by Size Exclusion Chromatography, Fourier Transformed Infrared Spectrometry, Small-angle X-ray Scattering (SAXS) and its cloud point was determined by measuring light transmittance. The studies showed low molecular polydispersivety, but different polarities in the macromolecules fractions. Due to the low solubility of Diol in water, a mixture of water/butyl diglycol was used as solvent. An extensive analysis by SAXS was performed for concentrations from 50 wt% to 80 wt% of Diol in solution. Small concentrations showed very low signal to noise ratio, making it impossible to be analysed. The scattering intensity including the form factor of polydisperse non-homogeneous spheres, and the structure factor of interacting hard spheres was fitted to the curves. As the polymer concentration is high, the fitting of form factors of direct and reverse micelles were compared. The results for direct micelles were better up to 80 wt%, whereas at 90 wt% and 95 wt% the curves were better fitted by reverse micelles. It might seem odd that direct micelles are present up to such high concentrations, but it might have been caused by the presence of butyl diglycol, which increases the solubility of Diol in water. The inner and outer radius of the micelles, electron density distribution, and interaction radius of the micelles were obtained. The polydispersivety increases with Diol concentration. Besides, the interaction radius increases with solvent concentration, even when reversed micelles are present. In the last case, accompanied by an increase of inner radius (water content), as there are fewer Diol molecules to involve the water nuclei, which become larger, further apart, and in less number

Comparative study and anticholinesterasic evaluation of essential oils from leaves, stems and flowers of myrciaria floribunda (H.West ex Willd.) O. Berg

Myrciaria floribunda (H.West ex Willd.) O.Berg, Myrtaceae, popularly known as “camboim amarelo”, was collected in Restinga de Jurubatiba (RJ, Brazil). Leaves, stems and flowers were individually submitted to hydrodistillation, affording the respective essential oils. Monoterpenes were the main group of essential oils from leaves (53.9 %) and flowers (55.4 %). Sesquiterpenes were more representative in stems (72.2 %). 1,8-cineole was the major constituent in the essential oil from leaves (38.4 %) and flowers (22.8 %). The major constituent from stems was (2E,6E)-farnesyl acetate (19.9 %). To our knowledge, these are the first contributions for essential oils from stems and flowers of M. floribunda. It was also performed the acetylcholinesterase inhibitory bioassay of the essential oil from stems, flowers and leaves of M. floribunda. Flowers and leaves oils had an IC50 of 1583 and 681 μg/mL, respectively, being both low to mild values.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Maternal hyperleptinemia is associated with male offspring’s altered vascular function and structure in mice

Children of mothers with gestational diabetes have greater risk of developing hypertension but little is known about the mechanisms by which this occurs. The objective of this study was to test the hypothesis that high maternal concentrations of leptin during pregnancy, which are present in mothers with gestational diabetes and/or obesity, alter blood pressure, vascular structure and vascular function in offspring. Wildtype (WT) offspring of hyperleptinemic, normoglycemic, Lepr db/+ dams were compared to genotype matched offspring of WT-control dams. Vascular function was assessed in male offspring at 6, and at 31 weeks of age after half the offspring had been fed a high fat, high sucrose diet (HFD) for 6 weeks. Blood pressure was increased by HFD but not affected by maternal hyperleptinemia. On a standard diet, offspring of hyperleptinemic dams had outwardly remodeled mesenteric arteries and an enhanced vasodilatory response to insulin. In offspring of WT but not Leprdb/+ dams, HFD induced vessel hypertrophy and enhanced vasodilatory responses to acetylcholine, while HFD reduced insulin responsiveness in offspring of hyperleptinemic dams. Offspring of hyperleptinemic dams had stiffer arteries regardless of diet. Therefore, while maternal hyperleptinemia was largely beneficial to offspring vascular health under astandard diet, it had detrimental effects in offspring fed HFD. These results suggest that circulating maternal leptin concentrations may interact with other factors in the pre- and post-natal environments to contribute to altered vascular function in offspring of diabetic pregnancie