884 resultados para agro-ecology


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The best irrigation management depends on accurate estimation of reference evapotranspiration (ET0) and then selection of the appropriate crop coefficient for each phenological stage. However, the evaluation of water productivity on a large scale can be done by using actual evapotranspiration (ETa), determined by coupling agrometeorological and remote sensing data. This paper describes methodologies used for estimating ETa for 20 centerpivots using three different approaches: the traditional FAO crop coefficient (K-c) method and two remote sensing algorithms, one called SEBAL and other named TEIXEIRA. The methods were applied to one Landsat 5 Thematic Mapper image acquired in July 2010 over the Northwest portion of the Sao Paulo State, Brazil. The corn, bean and sugar cane crops are grown under center pivot sprinkler irrigation. ET0 was calculated by the Penman-Monteith method with data from one automated weather station close to the study site. The results showed that for the crops at effective full cover, SEBAL and TEIXEIRA's methods agreed well comparing with the traditional method. However, both remote sensing methods overestimated ETa according to the degree of exposed soil, with the TEIXEIRA method presenting closer ETa values with those resulted from the traditional FAO K-c method. This study showed that remote sensing algorithms can be useful tools for monitoring and establishing realistic K-c values to further determine ETa on a large scale. However, several images during the growing seasons must be used to establish the necessary adjustments to the traditional FAO crop coefficient method.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study aimed at evaluating the oils extracted from seeds originating from agro-industrial waste, in order to identify the presence of bioactive compounds. Therefore, determinations of fatty acid profile, triacylglycerols, tocopherol composition, phytosterols, phenolic compounds, total carotenoids, and antioxidant capacity were performed in the oils of grape, guava, melon, passion fruit, pumpkin, soursop, and tomato seeds. Antioxidant capacity analysis was performed by the methods DPPH• , ABTS•+, FRAP, and β-carotene/linoleic acid, besides measure of oxidative stability in the oils. The oils showed to be predominantly unsaturated with high percentage of linoleic essential fatty acid (38.8 to 79.4%), besides presenting significant quantities of tocopherols, phytosterols, and phenolic compounds. Tomato and guava oils showed better results in the antioxidant capacity tests and pumpkin oil had higher induction period in the oxidative stability test (65.3 h). The results obtained in this study collect information that enables the use of new alternative sources of vegetable oils, obtained from agroindustrial waste, which may serve as raw material for food, chemical, and pharmaceutical industries.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Luciferid shrimps have short life spans and a rapid turnover of generations, engage in sequential spawning, and protect their eggs during incubation. This study investigates the ecology of Lucifer faxoni Borradaile, 1915 in the littoral zone, Ubatuba region, São Paulo. Sampling was conducted monthly from July 2005 to December 2006 using a Renfro net trawled over a distance of 50 m for a total sampling effort of 50 m² at each station. Nine stations were sampled, ranging from 1 to 15 m deep. Three stations each were grouped into zones 1, 2 and 3 (Z1, Z2 and Z3). Monthly values of salinity, temperature and rainfall were recorded at each station. The pre-buccal somite length (SL) of each specimen was measured. The results showed that in shallower zones (Z1 and Z2), 6306 individuals were captured, whereas in the deeper zone (Z3), 3808 specimens were captured, but no significant differences in SL was detected between the specimens from Z1 and Z2 and those from Z3 (ANOVA, p=0.25). The abundance of shrimps did not differ significantly between seasons (Tukey’s test, p=0.02) except in the spring. The sex ratio differed significantly over the seasons (χ², p<0.05). The results were closely associated with environmental factors with respect to the spatial and seasonal distribution of L. faxoni. Rainfall affected salinity directly, and contributed to the displacement of these shrimps to deeper areas.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Vegetal origin agro-industrial wastes are seen as a problem since the beginning of the industrial processes; however, they are becoming attractive as raw material for numerous purposes such as active enzymes and in the molecule bioprospecting area. Moreover, it is difficult to understand what the studied residue is consisted of in studies on agro-industrial waste, since the wastes names and constituents may vary according to the used equipment, as for waste from orange and mango processing. Thus, defining a specific waste, including comparisons between botanical and industrial descriptions, can help in understanding studies about wastes. The current review sought to contextualize such a scenario by gathering definitions, relevant information and studies on agro-industrial wastes and by-products, international enzymes market, and recent studies on bioactive compounds. In this context, waste from orange and mango are interesting because of the expression of these fruits on the world market; moreover, the processing does not include steps that could disrupt these biomolecules.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Artificial neural networks (ANNs) have been widely applied to the resolution of complex biological problems. An important feature of neural models is that their implementation is not precluded by the theoretical distribution shape of the data used. Frequently, the performance of ANNs over linear or non-linear regression-based statistical methods is deemed to be significantly superior if suitable sample sizes are provided, especially in multidimensional and non-linear processes. The current work was aimed at utilising three well-known neural network methods in order to evaluate whether these models would be able to provide more accurate outcomes in relation to a conventional regression method in pupal weight predictions of Chrysomya megacephala, a species of blowfly (Diptera: Calliphoridae), using larval density (i.e. the initial number of larvae), amount of available food and pupal size as input data. It was possible to notice that the neural networks yielded more accurate performances in comparison with the statistical model (multiple regression). Assessing the three types of networks utilised (Multi-layer Perceptron, Radial Basis Function and Generalised Regression Neural Network), no considerable differences between these models were detected. The superiority of these neural models over a classical statistical method represents an important fact, because more accurate models may clarify several intricate aspects concerning the nutritional ecology of blowflies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Beginning in the late 1980s, large groups of previously unidentified killer whales (Orcinus orca) were sighted off the west coast of Vancouver Island and in the Queen Charlotte Islands, British Columbia. Scientists working in this region produced two killer whale photo-identification catalogues that included both transient (mammal-eating) whales and 65 individual whales that investigators believed represented a distinct killer whale community (Ford et al. 1992, Heise et al. 1993). It was thought that these killer whales maintained a generally offshore distribution and were provisionally termed “offshores”; a term that has since been used as a population identifier for the eastern temperate North Pacific offshore killer whale population. Then in September 1992, 75 unidentified whales entered the Strait of Juan de Fuca just south and east of Victoria, British Columbia (Walters et al. 1992). Although most of these whales had not been seen before, two were matched to killer whales in the Queen Charlotte photo-identification catalogue (Ford et al. 1992, Heise et al. 1993) and were thus listed as “offshore” killer whales. During a similar time period, other large groups of killer whales, previously unidentified, were also being sighted off Alaska and California (Dahlheim et al. 1997; Nancy Black and Alisa Schulman- Janiger, unpublished data, respectively).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The occurrence of a species of Echinococcus (Rudolphi, 1801) on St Lawrence Island was noted by the writers in early 1950. Recognition of its unusual host relationships led to an investigation of the ecology of this cestode, E. sibiricensis Rausch & Schiller, 1954. It is the purpose of this paper to report the results of this work, with emphasis on alveolar hydatid disease in man, of which this cestode is the etiologic agent.