Statistics and kinetics of single-molecule electron transfer dynamics in complex environments: A simulation model study

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

Assessing land use by cattle in heterogeneous environments

The aim of this note is to describe preliminary results on assessment of land use by cattle, obtained in a pilot study using Geographic Information System (GIS). The research was carried out on a semi-natural pasture in Sweden, where the geographic positions of one cow were recorded during 25 consecutive days during summer. The cow, wearing a GPS collar, was integrated in a herd of 53 Hereford cattle. Each location point registered for the animal was considered as a sampling unit (N=3,097). The spatial distribution of ground declivity, water sources, cattle tracks, and classes of woody vegetation cover (forest, grassland with trees and open grassland) were recorded. The storage, processing and data analysis were carried out using the Idrisi and GS+ softwares. Three occupation zones were identified in function of the variation in the space used by the animal, which were occupied in a cyclical pattern; with the animal moving from one zone to another in cycles of five days. It was also clear that the cattle distribution in the area was neither random nor uniform, and it was affected by environmental characteristics that act as conditioners on its distribution. These preliminary results suggest that definition of zones of occupation and the environmental conditioners are promising tools to understand the land use by cattle

The ant fauna of hospitals: advancements in public health and research priorities in Brazil

Ants inhabit several types of natural and urban habitats, where they successfully nest. In urban environments, the hospitals should be considered priority for studies, as ants pose risks to human health due to their pathogen carrying potential. We aimed at surveying the literature about studies on ants in hospital settings in Brazil in the past 20 years. We found 40 papers in 22 journals, the first one published in 1993. Among them, 26 papers assessed pathogenic microorganisms on ants. We recorded 59 ant species, being Tapinoma melanocephalum the most common. The Minas Gerais and Sao Paulo states had the largest number of published papers. Mato Grosso do Sul and Rio Grande do Sul showed the highest number of species. Exotic ant species were recorded in all states, except Goias. Considering the potential to carry microorganisms and the importance of thorough studies on the ecology of ant species, our results can support and guide further research in Brazil. (C) 2015 Sociedade Brasileira de Entomologia. Published by Elsevier Editora Ltda. All rights reserved.

Thermoregulatory responses of goats in hot environments

Notwithstanding the solar radiation is recognized as a detrimental factor to the thermal balance and responses of animals on the range in tropical conditions, studies on the amount of thermal radiation absorbed by goats therein associated with data on their production and heat exchange are still lacking. Metabolic heat production and the heat exchange of goats in the sun and in the shade were measured simultaneously, aiming to observe its thermal equilibrium. The results showed that black goats absorb twice as much as the white goats under intense solar radiation (higher than 800 W m(-2)). This observation leads to a higher surface temperature of black goats, but it must not be seen as a disadvantage, because they increase their sensible heat flow in the coat-air interface, especially the convection heat flow at high wind speeds. In the shade, no difference between the coat colours was observed and both presented a lower absorption of heat and a lower sensible heat flow gain. When solar radiation levels increases from 300 to 1000 W m(-2), we observed an increase of the heat losses through latent flow in both respiratory and cutaneous surface. Cutaneous evaporation was responsible for almost 90 % of the latent heat losses, independently of the coat colour. Goats decrease the metabolic heat production under solar radiation levels up to 800 W m(-2), and increase in levels higher than this, because there is an increase of the respiratory rate and of the respiratory flow, but the fractions of consumed oxygen and produced carbon dioxide are maintained stable. The respiratory rate of black goats was higher than the white ones, under 300 W m(-2) (55 and 45 resp min(-1)) and 1000 W m(-2) (120 and 95 resp min(-1), respectively). It was concluded that shade or any protection against solar radiation levels above 800 Wm(-2) is critical to guarantee goat's thermal equilibrium. Strategies concerning the grazing period in accordance with the time of the day alone are not appropriate, because the levels of radiation depend on the latitude of the location.

Electrical conductivity of soybean seeds after storage in several environments

Membrane integrity, as measured by electrical conductivity (EC), is suggested as an indicator of seed vigor in soybean [Glycine max (L.) Merrill] seeds. This study evaluated the effect of storage time and temperature on EC of six soybean seed lots (two lots each of high, medium and low vigor). All seed lots were adjusted to 120 g kg(-1) seed moisture, sealed in aluminum foil packets and placed in storage at 10 and 20 degreesC or stored unsealed in multi-wall paper bags in warehouse (WH) conditions at Lexington, KY, USA for 486 days. Four of the six seed lots were also stored unsealed at 10 degreesC. All seed lots were sampled at 3-month intervals and evaluated for seed moisture (SMC), standard germination (SG) and vigor [accelerated aging (AA) and EC]. After 91 and 204 days in storage, samples initially stored at 20 degreesC and WH were moved to 10 degreesC and sampled at the same intervals. Seed moisture content for unsealed samples equilibrated at 107 g kg(-1) (+/-9 g kg(-1)) in both the WH and 10 degreesC environments. No change in SG occurred for seeds stored sealed (120 g kg(-1)) at 10 degreesC, except for the low vigor seed lots which declined significantly at the last sample date. The AA germination declined significantly for all, seed lots stored sealed at 10 degreesC, however the EC did not change during the same storage period. Seeds stored sealed at 20 degreesC and unsealed in the WH showed rapid declines in AA and SG and significant increases in EC. When these seeds were moved to 10 degreesC, however, the AA continued to decline while the EC remained at the same level (no significant change) for the remainder of the seed storage period. Thus whilst the AA declined in all environments, the EC only increased at higher temperatures (20 degreesC, WH) but showed little change during storage at 10 degreesC. Thus, precautions must be taken if using EC to measure soybean seed vigor following storage at 10 degreesC.

Clues to the presence of pathogenic fungi in certain environments

The presence of various pathogenic fungi in rather unsuspected hosts and environments has always attracted the attention of the scientific community. Reports on the putative role of animals in fungal infections of humans bear important consequences on public health as well as on the understanding of fungal ecology. Fungi are ubiquitous in nature and their great capacity for adaptation allows them to survive and indeed, to thrive, in plants, trees and other natural substrata. Nonetheless, we are just beginning to learn the significance that these diverse fungal habitats have on the increasing number of immunosuppressed individuals. The accidental or permanent presence of fungi in animals, plants, soils and watercourses should not be taken too lightly because they constitute the source where potential pathogens will be contracted. If those fungal habitats that carry the largest risks of exposure could be defined, if seasonal variations in the production of infectious propagules could be determined, and if their mode of transmission were to be assessed, it would be possible to develop protective measures in order to avoid human infection. Additionally, unsuspected avenues for the exploration of fungal survival strategies would be opened, thus enhancing our capacity to react properly to their advancing limits. This paper explores several ecological connections between human pathogenic fungi and certain animals, trees, waterways and degraded organic materials. The occurrence of such connections in highly endemic areas will hopefully furnish more precise clues to fungal habitats and allow the design of control programs aimed at avoiding human infection.

Morphological, morphometrical and ultrastructural characterization of Phrynops geoffroanus' (Testudines: Chelidae) blood cells, in different environments

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Use of vitamin D to reduce lameness in broilers reared in harsh environments

In tropical poultry-producing countries, poultry houses usually have little environmental control. This study investigated the effect of dietary vitamin D on the incidence of leg abnormalities of a fast-growing broiler strain reared under harsh conditions. In this study, 300 one-day-old male broilers were distributed in two treatments with three replicates of 50 birds each. One group was fed a placebo and the other group was fed 25-hydroxycholecalciferol (25-OH-D3) in a soluble form. The environmental variables were weekly recorded during until birds were 49 days old. Birds were weekly gait scored, and their walking speed and vertical force while walking were assessed. Post-mortem examination was performed and skeletal lesions were assessed. Control birds presented more leg problems than those that ingested 25-OH-D3. These results suggest that dietary vitamin D is effective in decreasing the severity of lameness by reducing tibial dyschondroplasia and other leg abnormalities.

Environmental heterogeneity: Anuran diversity in homogeneous environments

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A neural approach for determination of global energetic efficiency indicator in groundwater wells

In most of the cases, the systems of water distribution from groundwater wells use electrical submersible pumps. All electrical energy is applied to the pumps; however, other components (pipes, valves, etc.) of these systems are also responsible by the higher or lower consumption of electric energy. The supervisors and operators of the systems should thus have knowledge of the global energetic behavior of the process in order to administrate it properly. This work suggests a 'Global Energetic Efficiency Indicator' for groundwater wells by using mathematical equations and neural networks. Simulation results will be presented in order to demonstrate the validity of the proposed approach.

Single molecule electron transfer dynamics in complex environments

We propose a new theoretical approach to study the kinetics of the electron transfer (ET) under the dynamical influence of the complex environments with the first passage times (FPT) of the reaction events. By measuring the mean and high order moments of FPT and their ratios, the full kinetics of ET, especially the dynamical transitions across different temperature zones, is revealed. The potential applications of the current results to single molecule electron transfer are discussed.

Recent research developments in SnO2-based varistors

This paper discusses some advances in research conducted on SnO2-based electroceramics. The addition of different dopants, as well as several thermal treatments in oxidizing and inert atmospheres, were found to influence the microstructure and electrical properties of SnO2-based varistor ceramics. Measurements taken by impedance spectroscopy revealed variations in the height and width of the potential barrier resulting from the atmosphere in which thermal treatments were performed. High nonlinear coefficient values, which are characteristic of high-voltage and commercial ZnO varistors, were obtained for these SnO2-based systems. All the systems developed here have potentially promising varistor applications. (C) 2004 Elsevier B.V. All rights reserved.

Bacillus thuringiensis development from 1971 to 1996: Cases of a research group in Brazil

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

Ergonomic research applied in the design of pre-school furniture: The Mobipresc 3.6

This research describes the application of a scientific and technological model of Ergonomics in the design of pre-school furniture. The constant presence of the desk in early education and its influence in the relationship between the user and his educational environment determined the necessity of this project. The pre-school desk was considered as a work station, where the joint aspects of education and child anthropometry substantiate the problem. The review of the Historical application of Ergonomics in the Design of children's products consolidated the importance of this report. The development of ergonomic research, characterised by investigations of the Brazilian child's Anthropometry Data and Biomechanical Features, resulted in dimensional parameters of the user and physical characteristics of the present furniture. These elements, together with a comprehension of activities and needs in the pre-school, were connected with aspects of bibliographical revision to result in a series of recomendations for design. Through the methods of Ergonomic Design, a new proposal for the pre-school desk was developed, denominated Mobipresc 3.6.

Life-history strategies associated to reproduction of three Hyphessobrycon species (Characidae) in lentic environments of upper Paraná River basin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)