Efeito dos andrógenos na estabilização da preferência manual em machos adultos de sagui comum (Callithrix jacchus)

The role of steroids hormones on the behavior of vertebrates have been described as organizational and activational effects. These actions occur in different periods of the ontogenetic development as fetal, early post natal and during puberty (organizational effect) or modifying the expression of behavioral patterns during time life (activational effects). Studies on brain lateralization in hand use in human and non-human primates have shown that sexual hormones seems to participate in the process of handedness strength that begins in the puberal period and is stabilized at the adult age. The aim of this study was to investigate in adult male Callithrix jacchus if the strength of use of the hand in common marmoset adult male is stable (organizational effect) or androgens variations could affect its stability (activational effect). The preferential use of one hand in 14 common marmoset (Callithrix jacchus was studied in two contexts: (1) spontaneous holding food and directing the food to mouth (feeding episodes), and (2) forced reaching food tests where the animal have to reach the food through a hole within a cover plate with a central hole that allow the use of one hand only to reach the food. The records were made during 5 sessions/20 bouts each during baseline totalizing 100 episodes before two treatments. Firstly it was used GnRH antagonist: a single subcutaneous injection of 100µg de Cetrotide – acetate of cetrorrelix (Baxter Oncology GmbH, Germany) (n=10). Secondly, a single GnRH injection of 0.2mg of GnRH (Sigma – Aldrich) (n= 8) was used. After injections 20 successful attempts of hand use episodes was recorded in the 1st , 2 nd, 7th, 15th and 30 th days, totalizing in the whole period 100 episodes for each context, after both treatments. Fecal sampling to measure extracted fecal androgens was performed in all days of data collection across the length of the basal and during the experimental periods. Statistical analysis by mixed model, Tukey test to compare mean values after the two treatments, and Levene test to compare mean variance were used, all for p-value < 0.05. In basal phase 6 animals used preferentially the right hand, 5 the left and 3 were ambidextrous. Mean handedness index in basal phase were different from that after both treatment starting at 7th day. Mean variance of handedness index for spontaneous and forced activities does not differs before and after both treatments but the mean values for GnRH index were higher than that observed for its antagonist. These findings suggested that androgens have an activational effect on handedness in adult male C. jacchus

Avaliação de sistemas de lagoas de estabilização em série no Rio Grande do Norte

Stabilization ponds are biological treatment systems in that stabilization of organic matter is performed by the bacterial oxidation and / or reduction of photosynthetic algae. This study aimed to monitor and evaluate the efficiency of stabilization ponds in the Rio Grande do Norte State. Collections were made of the treated effluent, made directly in the output boxes of facultative lagoons and maturation (M1 and M2) and raw sewage (EB) that arrived at the stations. The variables analyzed were: pH, temperature, dissolved oxygen, total suspended solids, chlorophyll "a", apparent color, total phosphorus, organic nitrogen, ammonia nitrogen, Kjeldahl nitrogen, turbidity, cyanobacteria density and concentrations of microcystin. Variance analysis (ANOVA one way) observing the premises using the Tukey test, so as to check differences between treatments. The evaluate the stations found to COD removals in the bands of 48,8% (Pipa) to 75,8% (Caiçara Rio do Vento) and 57,5% (Pipa) to 83,0% (Santo Antônio), respectively. The mean concentrations of cyanobacteria varied from LFs density of 62,545 cels.mL-1 (Pedro Velho Roça) cels.mL-1 to 2,669,048 (Ponta Negra), while the final effluent showed range between 9,072 Cels.mL- 1 (Pedro Velho Roça) to 1,899,981 cels.mL-1 (Macau – Ilha de Santana) and the average concentrations of microcystin the final effluent ranged from 0.02 μg.L-1 (Ponta Negra) to 0.15 μg.L-1 (Macau – Ilha de Santana) at the studied the stations.

Mecanismos de transmissão de preços e parcelas de mercado: uma análise sobre as exportações brasileiras de manga

Climate and environmental conditions allowed Brazil to become one of the largest producers of tropical fruits in the world. The São Francisco Valley, over the years, has emerged as the main fruit-producing region of the country, especially mangos and grapes. The mango, which is produced in this region, has reached a good international position, especially in European and American markets. However, the domestic price has absorbed more and more the impact of fluctuations in the international market expectations affecting the production and marketing of producers. The objective of the study is to analyze the transmission ratio of export prices of the mango, with the American market prices and the European Union in the period from 2003 to 2013. It is intended also to analyze the factors affecting the fluctuations of exports Brazilian mango for the main import markets. To achieve the proposed objectives, we used, in the methodology, the autoregressive vector model, in order to find the price transmission mechanism and the mechanisms of impacts through the impulse response function. We also used, the Constant Market Share model, in order to observe the importance of the effects competitiveness, destination, and growth in world trade on the changes of Brazilian mango exports in the period. The data used were obtained from the database of the Ministry of Development and Foreign Trade - MIDIC and FAOSTAT (Food and Agriculture Organization of the United Nations). Among the results, it was found that the Brazilian domestic prices are influenced by the US market price, and that price shocks promoted this market can impact on the growth of the internal prices for several months. It was noted also that the competitiveness effect accounted for the largest portion of the effective growth of Brazilian exports, in other word, the country has improved its competitiveness among the other exporting countries.

Análise de volatilidade, integração de preços e previsibilidade para o mercado brasileiro de camarão

The present paper has the purpose of investigate the dynamics of the volatility structure in the shrimp prices in the Brazilian fish market. Therefore, a description of the initial aspects of the shrimp price series was made. From this information, statistics tests were made and selected univariate models to be price predictors. Then, it was verified the existence of relationship of long-term equilibrium between the Brazilian and American imported shrimp and if, confirmed the relationship, whether or not there is a causal link between these assets, considering that the two countries had presented trade relations over the years. It is presented as an exploratory research of applied nature with quantitative approach. The database was collected through direct contact with the Companhia de Entrepostos e Armazéns Gerais de São Paulo (CEAGESP) and on the official website of American import, National Marine Fisheries Service - National Oceanic and Atmospheric Administration (NMFS- NOAA). The results showed that the great variability in the active price is directly related with the gain and loss of the market agents. The price series presents a strong seasonal and biannual effect. The average structure of price of shrimp in the last 12 years was R$ 11.58 and external factors besides the production and marketing (U.S. antidumping, floods and pathologies) strongly affected the prices. Among the tested models for predicting prices of shrimp, four were selected, which through the prediction methodologies of one step forward of horizon 12, proved to be statistically more robust. It was found that there is weak evidence of long-term equilibrium between the Brazilian and American shrimp, where equivalently, was not found a causal link between them. We concluded that the dynamic pricing of commodity shrimp is strongly influenced by external productive factors and that these phenomena cause seasonal effects in the prices. There is no relationship of long-term stability between the Brazilian and American shrimp prices, but it is known that Brazil imports USA production inputs, which somehow shows some dependence productive. To the market agents, the risk of interferences of the external prices cointegrated to Brazilian is practically inexistent. Through statistical modeling is possible to minimize the risk and uncertainty embedded in the fish market, thus, the sales and marketing strategies for the Brazilian shrimp can be consolidated and widespread