Reproduction, food dynamics and exploitation level of Oreochromis niloticus (Perciformes: Cichlidae) from artisanal fisheries in Barra Bonita Reservoir, Brazil

Nile tilapia (Oreochromis niloticus), which is exotic to South America, is the most common species caught in artisanal fisheries at the Barra Bonita Reservoir, Southeastern Brazil. This species is of great socioeconomic importance for the region and keeps active a population of about 500 fishers. In the present study we assess reproduction, food dynamics and level of exploitation of O. niloticus, caught by artisanal fisheries in the Barra Bonita Reservoir. Specimens were collected monthly, from July 2004-June 2005, and a total of 1 715 specimens were analyzed. Each specimen was examined to obtain biological and biometric data: standard length (cm), total weight (g), reproductive data (sex and stage of maturation), and stomach contents (empty, partly full, and full). We also estimated the sex ratio (by macroscopic observation of gonads), reproductive period (by ovarian development and seasonal average of gonadosomatic index in females), and feeding habits (by stomach contents). The possible relationship between abiotic factors and the reproductive period was statistically verified using Spearman's Rank Correlation. The FiSAT (ELEFAN I) package was used to assess growth parameters, mortality rates and to infer exploitation rate from standard length frequencies. The O. niloticus population had a sex ratio of 1.3:1 (M:F). Results indicated that ripe females were captured throughout the year, with a higher frequency during the winter-2004 (with a frequency of 59%, at a mean temperature of 20.5°C), and in spring-2004 (with a frequency of 60.5% at a mean temperature of 21.18°C). The GSI mean values obtained by season were: winter-2004: 1.71; spring-2004: 1.72; summer-2005: 0.80, and autumn-2005: 1.19. The Spearman correlation indicated positive values with respect to pH, dissolved oxygen, electric conductivity, transparency and chlorophyll a, and negative values with respect to temperature, accumulated rainfall and altimetric benchmark. The main food items were phytoplankton and periphytic algae, observed in 99.6% of the analyzed stomachs. The estimated growth and mortality parameters were: L∞=33.60cm, k=0.63/year, longevity= 4.76years, Z=2.81/ year, M=1.20/year and F=1.61/year. The weight-length relationship was Ln Wt=-2.8532+2.8835 Ln Lp. The estimated yield per recruit values were as follows: E=0.570, Emax=0.776, E0.1=0.604 and E0.5=0.349. These results indicate that a well established population of O. niloticus is present at Barra Bonita Reservoir; with an active reproduction throughout the year, more intense during winter and spring, and that O. niloticus is a phytoplanktophagus species. There were no indications that this species is being overfished, we therefore recommend that, due to its exotic condition, no restrictions need to be taken on its fishing activities.

Bilevel approach for optimal location and contract pricing of distributed generation in radial distribution systems using mixed-integer linear programming

In this study, a novel approach for the optimal location and contract pricing of distributed generation (DG) is presented. Such an approach is designed for a market environment in which the distribution company (DisCo) can buy energy either from the wholesale energy market or from the DG units within its network. The location and contract pricing of DG is determined by the interaction between the DisCo and the owner of the distributed generators. The DisCo intends to minimise the payments incurred in meeting the expected demand, whereas the owner of the DG intends to maximise the profits obtained from the energy sold to the DisCo. This two-agent relationship is modelled in a bilevel scheme. The upper-level optimisation is for determining the allocation and contract prices of the DG units, whereas the lower-level optimisation is for modelling the reaction of the DisCo. The bilevel programming problem is turned into an equivalent single-level mixed-integer linear optimisation problem using duality properties, which is then solved using commercially available software. Results show the robustness and efficiency of the proposed model compared with other existing models. As regards to contract pricing, the proposed approach allowed to find better solutions than those reported in previous works. © The Institution of Engineering and Technology 2013.

Three-phase tri-state buck-boost integrated inverter

This paper presents a three-phase integrated inverter suitable for stand-alone and/or grid-connected applications. The usage of the special features of the tri-state coupled with the special space vector modulation allows the inverter to present an attractive degree of freedom for the controllers' design, i.e. input and output can be controlled independently. Additionally all controllers are based on dq0 transformation, the system are described and interesting simulation results are available to confirm the proposal. Finally, this paper presents experimental evaluations of the inverter feeding a three-phase stand-alone load confirming the remarkable features of the decoupling control. © 2013 IEEE.

Temporomandibular disorders, sleep bruxism, and primary headaches are mutually associated.

To investigate the association among temporomandibular disorders (TMD), sleep bruxism, and primary headaches, assessing the risk of occurrence of primary headaches in patients with or without painful TMD and sleep bruxism. The sample consisted of 301 individuals (253 women and 48 men) with ages varying from 18 to 76 years old (average age of 37.5 years). The Research Diagnostic Criteria for Temporomandibular Disorders were used to classify TMD. Sleep bruxism was diagnosed by clinical criteria proposed by the American Academy of Sleep Medicine, and primary headaches were diagnosed according to the International Classification of Headache Disorders-II. Data were analyzed by chi-square and odds ratio tests with a 95% confidence interval, and the significance level adopted was .05. An association was found among painful TMD, migraine, and tension-type headache (P < .01). The magnitude of association was higher for chronic migraine (odds ratio = 95.9; 95% confidence intervals = 12.51-734.64), followed by episodic migraine (7.0; 3.45-14.22) and episodic tension-type headache (3.7; 1.59-8.75). With regard to sleep bruxism, the association was significant only for chronic migraine (3.8; 1.83-7.84). When the sample was stratified by the presence of sleep bruxism and painful TMD, only the presence of sleep bruxism did not increase the risk for any type of headache. The presence of painful TMD without sleep bruxism significantly increased the risk in particular for chronic migraine (30.1; 3.58-252.81), followed by episodic migraine (3.7; 1.46-9.16). The association between painful TMD and sleep bruxism significantly increased the risk for chronic migraine (87.1; 10.79-702.18), followed by episodic migraine (6.7; 2.79-15.98) and episodic tension-type headache (3.8; 1.38-10.69). The association of sleep bruxism and painful TMD greatly increased the risk for episodic migraine, episodic tension-type headache, and especially for chronic migraine.

Modelos para estimar a ingestão ótima de metionina + cistina para poedeiras comerciais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Levedura como pronutriente em dietas de matrizes e alevinos de Tílápia-do-Nilo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Associação da massa muscular esquelética com variáveis demográficas, antropométricas, dietéticas, bioquímicas e aptidão física de adultos clinicamente selecionados para programa de mudança de estilo de vida (MEV)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Períodos de interferência de plantas daninhas em cultivares de girassol

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Conteúdo celular do leite bubalino proveniente de quartos mamários sadios e portadores de mastite

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Prevalência de má oclusão e necessidade de tratamento ortodôntico, comparando a classificação de Angle e o índice de estética dentária, na cidade de Lins-SP

Pós-graduação em Odontologia Preventiva e Social - FOA

Viabilidade econômica da utilização dos resíduos da bananicultura na alimentação de cordeiros confinados

Aimed to analyze the economic feasibility of replacing hay Cynodon spp by hay banana crop residues in diet of lambs. We used 25 Santa Inês lambs, with an average age of five months and an average initial weight of 26.5kg, distributed in a completely randomized design with five treatments (40% hay Cynodon spp. + 60% concentrate, 20% hay banana leaf and 20% of Cynodon spp. + 60% concentrate, 40% of banana leaf hay + 60% concentrate, 20% hay pseudostem of banana and 20% of Cynodon spp. + 60% concentrate, 40% hay pseudostem of banana + 60% concentrate). After 69 days of experiment the animals were slaughtered. Possession of the cost of each diet and consumption of animals was calculated economic feasibility. Treatment with 40% of banana leaf hay + 60% concentrate showed the best economic indicators, based on the highest net income, the higher rate of return to higher profitability and marketing of live animals or slaughtered. The inclusion of banana crop residues in the diet of growing lambs increases the economic viability of the activity.

Broad-scale spatial patterns of canopy cover and pond morphology affect the structure of a Neotropical amphibian metacommunity

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

Adoção de práticas de Green Supply Chain Management: mecanismos de indução e a importância das empresas focais

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

Combined photoelectrocatalytic/electro-Fenton process using a Pt/TiO2NTs photoanode for enhanced degradation of an azo dye: A mechanistic study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)