Leaf-litter amount as a factor in the structure of a ponerine ants community (Hymenoptera, Formicidae, Ponerinae) in an eastern Amazonian rainforest, Brazil

Leaf-litter amount as a factor in the structure of a ponerine ants community (Hymenoptera, Formicidae, Ponerinae) in an eastern Amazonian rainforest, Brazil. Leaf-litter may be an important factor in structuring ponerine ant communities (Hymenoptera, Formicidae, Ponerinae) in tropical rainforests. We specifically examined how leaf-litter affects the structure of a ponerine ant community in primary Amazonian rainforest sites at the Ferreira Penna Scientific Station, Pará, Brazil. A total of 53 species belonging to eight genera of three ponerine tribes were collected with mini-Winkler extractors. The amount of leaf-litter positively affected the abundance and richness of the ponerine ant community, and also influenced species composition. Nearby samples often had low species similarity, especially when adjacent samples differed in the amount of leaf-litter. Leaf-litter availability in Amazonian primary forests is a key factor for distribution of ground-dwelling ponerine species, even at small scales.

Senescent stem-galls in trees of Eremanthus erythropappus as a resource for arboreal ants

Senescent stem-galls in trees of Eremanthus erythropappus as a resource for arboreal ants. Members of the dipteran families Tephritidae and Cecidomyiidae are inducers of stem-galls in Eremanthus erythropappus (DC.) MacLeish (Asteraceae), a tree common in the state of Minas Gerais, Brazil. When senescent, these galls become available to other organisms, such as ants. The present study describes a community of ants having benefitted from this process of ecosystem-engineering. The colonies in question inhabit the senescent stem-galls of trees of E. erythropappus and were examined in view of answering the following questions: i) whether the presence of stem-galls had any bearing on the richness, composition, or size of the ant colonies therein; and ii) whether the ants displayed any preferences regarding the shape and/or size of the galls. The study was conducted in populations of E. erythropappus trees near the city of Ouro Preto, MG. A total of 227 galls were collected, 14% of which were occupied by ants, belonging to eight different species. Half of the species occupied galls of both morphotypes (fusiform and globular), although we observed a marked preference for larger, globular shapes. Overall, our results showed the galls to be an effective and abundant resource, helping to maintain the diversity of the ants in the canopy. We also observed the occurrence of outstations and polydomic nests, although an in-depth examination of the influence of galls on this type of structuring has not been investigated.

Necrophagous diptera associated with wild animal carcasses in southern Brazil

Necrophagous Diptera associated with wild animal carcasses in southern Brazil. The aim of this study was to acquire a better knowledge concerning the diversity of necrophagous Diptera that develop on wild animal carcasses. For this purpose, the decomposition of six wild animal carcasses was observed in order to collect and identify the main species of necrophagous flies associated with the decomposition process. The carcasses were found on highways near the cities of Pelotas and Capão do Leão in the initial stage of decomposition, with no significant injuries or prior larval activity. Four wild animal models were represented in this study: two specimens of Didelphis albiventris Lund, 1840; two Tupinambis merianae Linnaeus, 1758; one Nothura maculosa Temminck, 1815; and one Cerdocyon thous Linnaeus, 1766. A total of 16,242 flies from 14 species were reared in the laboratory, where Muscidae presented the greatest diversity of necrophagous species. Overall, (i) carcasses with larger biomass developed a higher abundance of flies and (ii) the necrophagous community was dominated by Calliphoridae, two patterns that were predicted from published literature; and (iii) the highest diversity was observed on the smaller carcasses exposed to the lowest temperatures, a pattern that may have been caused by the absence of the generalist predator Chrysomya albiceps (Wiedemann, 1819). (iv) An UPGMA analysis revealed a similar pattern of clusters of fly communities, where the same species were structuring the groupings.

Estudo comparativo sobre filtragem de sinais instrumentais usando transformadas de Fourier e Wavelet

A comparative study of the Fourier (FT) and the wavelet transforms (WT) for instrumental signal denoising is presented. The basic principles of wavelet theory are described in a succinct and simplified manner. For illustration, FT and WT are used to filter UV-VIS and plasma emission spectra using MATLAB software for computation. Results show that FT and WT filters are comparable when the signal does not display sharp peaks (UV-VIS spectra), but the WT yields a better filtering when the filling factor of the signal is small (plasma spectra), since it causes low peak distortion.

Theoretical investigation of electronic excitation transfer between chlorophylls in light-harvesting antenna of photosystem ii using quantum computers

The excitation energy transfer between chlorophylls in major and minor antenna complexes of photosystem II (PSII) was investigated using quantum Fourier transforms. These transforms have an important role in the efficiency of quantum algorithms of quantum computers. The equation 2n=N was used to make the connection between excitation energy transfers using quantum Fourier transform, where n is the number of qubits required for simulation of transfers and N is the number of chlorophylls in the antenna complexes.

APARATO ELETROQUÍMICO PARA SISTEMA DE AQUISIÇÃO DE DADOS MULTICANAL COM RESOLUÇÃO ESPAÇO-TEMPORAL

Spatiotemporal pattern formation in reaction-transport systems takes place spontaneously when the system is kept far from thermodynamic equilibrium. Targets, reaction fronts, waves, spirals, spots and stripes are some typical examples of selforganized structuring. In electrochemical systems, monitoring spatiotemporal patterns of potential in the solid/liquid interface can be done by the use of equally distributed microprobes located close to the working electrode. However, the physical size of each probe can limit the spatial resolution and alter mass transport properties. In contrast, the direct measurement of discrete electrodes does not suffer from this limitation and allows the accurate manipulation of the spatial coupling through changes in resistors connected to the electric circuit. In this paper, the development of an electrochemical setup for multichannel data acquisition with spatiotemporal resolution is described, especially to monitor low levels of currents usually observed in the electro-oxidation of small organic molecules.

Adherence and perceptions regarding simulation training in undergraduate health Sciences

BACKGROUND: Simulation techniques are spreading rapidly in medicine. Suc h resources are increasingly concentrated in Simulation Laboratories. The MSRP-USP is structuring such a laboratory and is interested in the prevalence of individual initiatives that could be centralized there. The MSRP-USP currently has five full-curriculum courses in the health sciences: Medicine, Speech Therapy, Physical Therapy, Nutrition, and Occupational Therapy, all consisting of core disciplines. GOAL: To determine the prevalence of simulation techniques in the regular courses at MSRP-USP. METHODS: Coordinators of disciplines in the various courses were interviewed using a specifically designed semi-structured questionnaire, and all the collected data were stored in a dedicated database. The disciplines were grouped according to whether they used (GI) or did not use (GII) simulation resources. RESULTS AND DISCUSSION: 256 disciplines were analyzed, of which only 18.3% used simulation techniques, varying according to course: Medicine (24.7.3%), Occupational Therapy (23.0%), Nutrition (15.9%), Physical Therapy (9.8%), and Speech Therapy (9.1%). Computer simulation programs predominated (42.5%) in all five courses. The resources were provided mainly by MSRP-USP (56.3%), with additional funding coming from other sources based on individual initiatives. The same pattern was observed for maintenance. There was great interest in centralizing the resources in the new Simulation Laboratory in order to facilitate maintenance, but there was concern about training and access to the material. CONCLUSIONS: 1) The MSRP-USP simulation resources show low complexity and are mainly limited to computer programs; 2) Use of simulation varies according to course, and is most prevalent in Medicine; 3) Resources are scattered across several locations, and their acquisition and maintenance depend on individual initiatives rather than central coordination or curricular guidelines

A multicriteria model to assess tractors used in family agriculture

In recent years, public policy has been offering subsidized credit for machine purchase to family farmers. However, there is no methodological procedure to select a suitable tractor for these farmers' situation. In this way, we aimed to develop a selection model for smallholder farmers from Pelotas city region in the state of Rio Grande do Sul. Building a multicriteria model to aid decisions is divided into three main stages: structuring stage (identifying stakeholders, decisional context and model creation), evaluation stage (stakeholder preference quantification) and recommendation stage (choice selection). The Multicriteria method is able to identify and value the criteria used in tractor selection by regional family farmers. Six main evaluation areas were identified: operational cost (weight 0.20), purchase cost (weight 0.22), maintainability (weight 0.10), tractor capacity (weight 0.26), ergonomics (weight 0.14) and safety (weight 0.08). The best-rated tractor model (14.7 kW rated power) also was the one purchased by 53.3% of local families.

Collagen arrangement in hepatic granuloma in mice infected with Schistosoma mansoni: dependence on fiber radiation centers

The collagen structure of isolated and in situ liver granuloma from Swiss Webster mice infected with Schistosoma mansoni was sequentially and three-dimensionally analyzed during different times of infection (early acute, acute, transitional acute-chronic, and chronic phases) by laser scanning confocal microscopy and electron scanning variable vacuum microscopy. The initial granuloma structure is characterized by vascular collagen residues and by anchorage points (or fiber radiation centers), from where collagenous fibers are angularly shed and self-assembled. During the exudative-productive stage, the self-assembly of these fibers minimizes energy and mass through continuous tension and focal compression. The curvature or angles between collagen fibers probably depends on the fibroblastic or myofibroblastic organization of stress fibers. Gradually, the loose unstable lattice of the exudative-productive stage transforms into a highly packed and stable architecture as a result of progressive compactness. The three-dimensional architecture of granulomas provides increased tissue integrity, efficient distribution of soluble compounds and a haptotactic background to the cells.

A spectral analysis of the myoelectric activity of the left colon in patients with schistosomiasis mansoni

The objective of the present study was to perform a spectral analysis of the electrical activity of the left colon of patients with hepatosplenic schistosomiasis. Thirty patients were studied, divided into 2 groups: group A was composed of 14 patients (9 males and 5 females) with hepatosplenic schistosomiasis and group B was composed of 16 female patients without schistosomiasis mansoni. Three pairs of electrodes were implanted in the left colon at the moment of the surgical treatment. The signals of the electric activity of the colon were captured after postoperative recovery from the ileus and fed into a computer by means of a DATAQ data collection system which identified and captured frequencies between 0.02 and 10 Hz. Data were recorded, stored and analyzed using the WINDAQ 200 software. For electrical analysis, the average voltage of the electrical wave in the three electrodes of all patients, expressed as millivolts (mV), was considered, together with the maximum and minimum values, the root mean square (RMS), the skewness, and the results of the fast Fourier transforms. The average RMS of the schistosomiasis mansoni patients was 284.007 mV. During a long period of contraction, the RMS increased in a statistically significant manner from 127.455 mV during a resting period to 748.959 mV in patients with schistosomiasis mansoni. We conclude that there were no statistically significant differences in RMS values between patients with schistosomiasis mansoni and patients without the disease during the rest period or during a long period of contraction.

Oxidative enzymes activity in sugarcane juice as a function of the planting system

In Brazil, the largest producer of sugarcane in the world, the industrial process transforms this crop into ethanol and/or granulated sugar. Some cultivars exhibit enzymatic browning in the extracted sugarcane juice at levels harmful to the manufacturing process of white granulated sugar. The objective of this study was to assess the effect of sugarcane straw used as soil coverage, the use of different planting systems, and treatments with hydrogel polymer on enzymatic activity. The cultivar RB 86 7515 was sampled for 8 months; the first sample was obtained by cutting the upper portion of the stalk at the internode, which was taken to the laboratory for determination of the enzymatic activity of polyphenoloxidase (PPO) and peroxidase (POD). The soil coverage with different forms of straw as well as the planting systems did not change the enzymatic activity of polyphenoloxidase (PPO) and peroxidase (POD). The polyphenoloxidase (PPO) activity increased with the use of a polymer due to increased polyphenoloxidase (PPO) activity in the groove system. The enzymes studied showed changes in activity during the experimental period. The production of sugar at the end of the season (August to November) avoids the periods of highest enzymatic activity.

From semi-stagnation to growth in a sino-centric market

According to recent available information, the Brazilian economy may be entering a cycle of sustained growth. The dominant current interpretation points to the progresses made in terms of monetary stability, Balance of Payments and structural reforms. Indeed, without monetary stability and the commercial opening of the economy, investments would not be increasing and credit growth would not be helping the emergence of millions of new consumers. But these achievements should be taken as generally conditioning, rather than actually shaping the new picture. Some unexpected (not rarely positive) consequences of overcoming the long enduring semi-stagnation, the emergence of China as a major player, and its consequences on the necessary re-structuring of the Brazilian industry, seem to be decisive in the present day redefinition of the Brazilian GDP growth potential.