influence of different forms of outcome information on the neural substrates of the acquisition and representation of categories

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2012

Comparative Analysis of Signals Restoration by Different Kinds of Approximation

The comparative analysis of continuous signals restoration by different kinds of approximation is performed. The software product, allowing to define optimal method of different original signals restoration by Lagrange polynomial, Kotelnikov interpolation series, linear and cubic splines, Haar wavelet and Kotelnikov-Shannon wavelet based on criterion of minimum value of mean-square deviation is proposed. Practical recommendations on the selection of approximation function for different class of signals are obtained.

Concentration of nutrients in the apple fruits at different ages

On an apple grove situated at Buri, State of São Paulo, fruits were collected from trees 1-2; 3-4; 4-5, and 6 - 7 years old. The fruits were analysed for N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn. The authors concluded: a) the concentrations of the nutrients in the fruits differ according to the variety, age of the tree and age of the fruit; b) the concentrations of nutrients decrease with aging of the fruits; c) the concentrations of the macronutrients obey the following order: N>K>P>Ca>S> Mg; d) for the micronutrients, the following order was ob -served: Fe > B > Mn > Cu > Zn.

Spatio-temporal pattern formation in microemulsions under different physical and chemical conditions

Otto-von-Guericke-Universität Magdeburg, Fakultät für Naturwissenschaften, Dissertation, 2016

Comparative study of wax glands in four Meliponini bees (Hymenoptera, Apidae) producing different quantities of wax

The developmental degree of the wax glands was compared in four Meliponini bees, that produce different quantities of wax. The histological data and height average of the wax epithelium during the time in which the maximum production of wax is expected, are in accordance with the rates of wax produced by the species. In Lestrimelitta limao (Smith, 1863) a species which has cleptobiotic habits, and frequently rob wax from the attacked colonies, the height of wax epithelium was the lowest among the studied species. The cells seem to show an abnormal vacuolated cytoplasm, in the phase in which they would be producing wax.

Growth, molt and survival of Palaemonetes argentinus (Decapoda, Caridea) under different light-dark conditions

Growth, survival and molting rate in Palaemonetes argentinus Nobili, 1901 were compared under different light-dark conditions. During 80 days, 150 immatures of both sexes (initial mean weight 0.09±0.002g), from Los Padres lagoon, Mar del Plata, Argentina, were maintained in aquaria at 19±0.4°C under three light conditions: 0:24, 10:14 and 13:11 (L-D). They were fed daily on an artificial diet (45% proteins, 17.2% lipids, 7% water, 7% ash). Good weight increment was obtained with the three treatments, finding a positive linear correlation between mean weight and time (0:24, r=0.97; 10:14, r=0.99; 13:11, r=0.98). There were no significant differences in the percentage increment in mean weight among the treatments (0:24, 19.3%; 10:14, 29.3% and 13:11, 26.5%) (p<0.05). Molting rate was significantly higher at a long-day photoperiod (MR=1.7) than at a short-day (MR=0.6) or continuous dark condition (MR=0.3) (p<0.05). The lowest survival was found in animals maintained under 13:11 L-D conditions (77%), being statistically different of the other two treatments (92% and 89% at 10:14 and 0:24, respectively) (p<0.05). These results suggest that the best growth and survival in P. argentinus result with a 10:14 L-D cycle, and that the growth is less affected by photoperiod than molting rate and survival.

Oviposition behaviour of Gryon gallardoi (Hymenoptera, Scelionidae) on eggs of different ages of Spartocera dentiventris (Hemiptera, Coreidae)

The oviposition behaviour of Gryon gallardoi (Brèthes, 1914) on eggs of Spartocera dentiventris Mendonça Jr. (Berg, 1884) of different ages (2, 3, 4, 5, 6, 7, 8 and 12 days) was investigated. Groups of 12 eggs of each age were exposed to single females of G. gallardoi, and the oviposition behaviour was recorded under a stereomicroscope for two hours. Ten replicates were used for each age. In order to identify the moment the parasitoid egg was released inside the host, 1-day old eggs of S. dentiventris were exposed to G. gallardoi females, and the oviposition was interrupted at intervals of 20, 40, 60, 80, 100, 120, 140 and 160s after ovipositor insertion had initiated. Five behavioural steps were recorded: drumming, ovipositor insertion, marking, walking and resting. The average drumming and ovipositor insertion times increased with the host age (P<0.01). Ovipositor insertion usually occurred next to the longitudinal extremities of the host eggs. Marking took on average 19.5 ± 0.7s, and as walking and resting, was not affected by host age. Self-parasitism behaviour was observed in only 13.8 ± 2.3% of the eggs, being more evident with increasing patch depletion (reduction in non-parasitized eggs in the egg group, P<0.01), again with no variation due to changes in host egg age. For all ages tested, self-parasitized host eggs were less frequently contacted and accepted than non-parasitized ones (P<0.01). The parasitoid egg was released 137.0 ± 3.7s after ovipositor insertion. Spartocera dentiventris egg condition can lead to parasitoid behavioural changes, especially during the process of host choice and discrimination.

Calliphorid fly (Diptera, Calliphoridae) attraction to different colored traps in the Tingua Biological Reserve, Rio de Janeiro, Brazil

The present study intended to analyze calliphorid attraction to traps painted in a variety of colors and the calliphorid constancy index in the Tingua Biological Reserve, Rio de Janeiro state, Brazil. The Diptera were collected monthly in the Reserve, between 2002 and 2005, totaling 24 samplings. Four traps containing sardines as bait were painted olive green, blood red, black, or white and exposed for 48 h at four equidistant points, 50 m from each other. To determine the calliphorid species constancy, the Bodenheirmer constancy index was used throughout the study. To analyze differences in the total abundance between species and in their color selection, an ANCOVA test with a significance level of 5 % and a Tukey post-test were used, considering the categories species and color as cofactors and climatic variables as co-variables (temperature, relative humidity and precipitation), since the samples were collected over two years. 10,444 insects were captured. Of these, 56 % belonged to the Calliphoridae family, totaling 13 species, with the most frequent species being Laneela nigripes (28.5 %), Hemilucilia semidiaphana (17 %), and Mesembrinella sp. (16.4 %). The other species had frequencies lower than 12 %. Nine species were considered constant, two accessories, and two accidental. The data indicated that the most frequent species presented significant differences between themselves concerning abundance over the captured months, however, the Tukey post-test indicated differences only between a few of them. The black trap presented the higher relative calliphorid frequency (27.34 %), followed by green (25 %), red (24.0 %), and white (23.7 %), although the species abundance in the different colored traps did not differ significantly among themselves. Therefore, there was no Calliphorid flies preference for any of the tested colors.

Diet of Astyanax paranae (Characidae) in streams with different riparian land covers in the Passa-Cinco River basin, southeastern Brazil

An analysis of the diet of Astyanax paranae Eigenmann, 1914 in nine streams located in the Passa-Cinco River basin (upper Paraná River system) was performed to investigate the feeding habits of this species, check for possible spatial variations in diet and to investigate the influence of riparian vegetation in the composition of the diet. Stomach contents of 243 specimens were analyzed by the methods of relative frequency of occurrence and volume, and the diet was characterized by the alimentary index (AIi). The species showed insectivorous feeding habits, with a predominance of terrestrial and aquatic insects in the diet, varying by location. In most streams, resources of allochthonous origin were the most consumed. The participation of aquatic insects and terrestrial plants were high in most streams, while terrestrial insects and invertebrates were highest in streams with a greater presence of riparian forest. The two streams located draining pasture fields were the only places were A. paranae consumed algae and macrophyte fragments. These results were corroborated by the analysis of similarity (ANOSIM): the descriptor "percentage of riparian forest" was the highest environmental influence on the diet of A. paranae. The study shows that riparian forest percentage on the stream reach determines the species diet composition, but A. paranae is also able to gather enough food resources in a variety of severely degraded environments.

Comparative cytogenetics in different populations of the cavernicolous diplopod Pseudonannolene strinatii (Diplopoda, Pseudonannolenidae)

Different populations of Pseudonannolene strinatii Mauriès, 1974 collected from three caves in Iporanga, state of São Paulo, were cytogenetically compared using techniques of conventional coloration, C-banding and silver nitrate impregnation. Specimens were morphologically similar and small cytogenetic differences were observed between the populations with relation to the distribution of constitutive heterochromatin.

Assessment of fish assemblages in streams of different orders in the Upper Paraná River basin, Central Brazil

The aim of this study was to test whether the richness observed and the biomass per trophic group of fish assemblages vary depending on the order (1st and 2nd) of the streams located in three different basins of the Upper Paraná River Basin, Central Brazil. Samples were collected between April and September, 2009, in 27 streams of the Meia Ponte, Piracanjuba and Santa Maria River basins. A total of 4,879 specimens were collected distributed in 59 species and 19 families. The statistical analyses carried out indicate that the observed richness and biomass of omnivore fish were influenced by the interaction of two factors: stream order and basin. The 2nd order streams located in the Santa Maria basin presented significant differences in the observed richness and omnivore biomass when compared to i) 1st order streams in the same basin (only richness) or in the Piracanjuba and Meia Ponte basin; ii) 2nd order streams in the Piracanjuba (only omnivore biomass) and Meia Ponte Rivers basins. Results are discussed considering the influence of geomorphic processes on fish assemblages and food availability.

Taxonomic and numeric structure of Chironomidae (Diptera) in different habitats of a Neotropical floodplain

We characterized the local benthic Chironomidae by analyzing the numerical density, biomass, diversity index of Shannon-Wiener and dominance of larvae in the main channel of the Ivinhema River, in a secondary channel, in five lakes connected to the main channel and in five lakes without connection. Of the 68 taxa identified, Aedokritus sp., Tanytarsus sp., Chironomus strenzkei Fittkau, 1968 and Procladius sp.1 were found in all sampling sites and were considered morphospecies with greater of greatest ecological plasticity. Chironomus strenzkei Fittkau, 1968, contributed with the greatest biomass in the central region of lakes without connection, whereas Aedokritus sp. dominated in the littoral of lakes. The greater values of diversity indices in the littoral region of channels were due to the greater water flow and to the higher food availability in these areas. The dominance indices, by contrast, were greater on the central region of these environments. The littoral region has exclusive characteristics, representing habitats that could play important controlling in the numerical density and index diversity on the ecosystem, whereas that the biomass of benthic invertebrates in the central region in some biotopes would have different spatial probably according organisms drift.

Spatial competition between two candidates of different quality: the effects of candidate ideology and private information

This paper examines competition in a spatial model of two-candidate elections, where one candidate enjoys a quality advantage over the other candidate. The candidates care about winning and also have policy preferences. There is two-dimensional private information. Candidate ideal points as well as their tradeoffs between policy preferences and winning are private information. The distribution of this two-dimensional type is common knowledge. The location of the median voter's ideal point is uncertain, with a distribution that is commonly known by both candidates. Pure strategy equilibria always exist in this model. We characterize the effects of increased uncertainty about the median voter, the effect of candidate policy preferences, and the effects of changes in the distribution of private information. We prove that the distribution of candidate policies approaches the mixed equilibrium of Aragones and Palfrey (2002a), when both candidates' weights on policy preferences go to zero.

Parametric analysis of different compact tension specimens for fracture toughness characterisation in woven composite materials

Estudi elaborat a partir d’una estada a l’ Imperial College London, entre juliol i novembre de 2006. En aquest treball s’ha investigat la geometria més apropiada per a la caracterització de la tenacitat a fractura intralaminar de materials compòsits laminats amb teixit. L’objectiu és assegurar la propagació de l’esquerda sense que la proveta falli abans per cap altre mecanisme de dany per tal de permetre la caracterització experimental de la tenacitat a fractura intralaminar de materials compòsits laminats amb teixit. Amb aquesta fi, s’ha dut a terme l’anàlisi paramètrica de diferents tipus de provetes mitjançant el mètode dels elements finits (FE) combinat amb la virtual crack closure technique (VCCT). Les geometries de les provetes analitzades corresponen a la proveta de l’assaig compact tension (CT) i diferents variacions com la extended compact tension (ECT), la proveta widened compact tension (WCT), tapered compact tension (TCT) i doubly-tapered compact tension (2TCT). Com a resultat d’aquestes anàlisis s’han derivat diferents conclusions per obtenir la geometria de proveta més apropiada per a la caracterització de la tenacitat a fractura intralaminar de materials compòsits laminats amb teixit. A més, també s’han dut a terme una sèrie d’assaigs experimentals per tal de validar els resultats de les anàlisis paramètriques. La concordança trobada entre els resultats numèrics i experimentals és bona tot i la presència d’efectes no previstos durant els assaigs experimentals.

Schistosoma mansoni antigenic extracts obtained by different extraction procedures

Solubilization of Schistosoma mansoni antigens was obtained by agitation of adult worms in a 3M KCl solution. The protein contents of the KCl extrats varied from 0.35 to 0.96 mg/ml. Sera from 97 patients with hepatointestinal shistosomiasis and viable eggs in stools from a Brazilian endemic area were studied by immunoelectroomophoresis and Ouchterlony immunodiffusion methods with the KCl extract and with another antigen, obtained by homogenization of adult schistosomes in saline. The rate of positiveness of immunoprecipitation deterctions by immunoelectroomophoresis with the KCl extract was 53.5%. A correlation was verified between methods of detection and extration procedures, resulting in a better association of the extract obtained by agitation in 3M KCl and immunoelectroomophoresis.