936 resultados para densidade populacional


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Para estudar o efeito da densidade de plantas sobre a produção de vagens e seus componentes na cultura do amendoim cv. Tatu, em solos com diferentes fertilidades, foram realizados três experimentos, em condições de campo, no município de Pontal, SP, em um Latossolo Roxo, em anos agrícolas distintos, no cultivo das águas. As densidades estudadas foram 5, 8, 11, 14, 17, 20, 23 e 26 plantas por metro, em espaçamento de 0,60 m entre linhas. O componente de produção responsável pela variação da produção de vagens por planta foi o número de vagens, tendo diminuído com o aumento da densidade de plantas. Nas maiores densidades de plantas, as produções por planta foram menores, todavia devido à maior população de plantas, foram obtidas nestas as maiores produtividades de vagens. Produtividades de vagens, sem perdas significativas em relação às maiores densidades, foram obtidas nas densidades de 14 plantas por metro em solo de alta fertilidade e de 11 plantas por metro em solos de média/baixa fertilidades, que originaram, respectivamente, 12,92, 10,67 e 10,93 plantas por metro à colheita.

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OBJETIVO: Estimar a prevalência de asma em crianças e adolescentes e identificar fatores associados. MÉTODOS: Estudo transversal de base populacional com 1.185 crianças e adolescentes de ambos os sexos de São Paulo, SP, de 2008 a 2009. As informações foram coletadas por meio de entrevistas domiciliares e os participantes foram selecionados a partir de amostragem probabilística, estratificada por sexo e idade, e por conglomerados em dois estágios (setores censitários e domicílios). Foi realizada regressão múltipla de Poisson na análise ajustada entre o desfecho e variáveis sociodemográficas, econômicas, estilo de vida e condições de saúde. RESULTADOS: Dos entrevistados, 9,1% (IC95% 7,0;11,7) referiram asma. Após análise ajustada, identificaram-se os seguintes fatores independentemente associados ao agravo: idade (zero a quatro anos/15 a 19) RP = 3,18 (IC95% 1,20;8,42), idade (cinco a nove anos/15 a 19) RP = 6,37 (IC95% 2,64;15,39), idade (10 a 14 anos/15 a 19) RP = 4,51 (IC95% 1,95;10,40), alergia (sim/não) RP = 2,22 (IC95% 1,24;4,00), rinite (sim/não) RP = 2,13 (IC95% 1,22;3,73), problemas de saúde nos 15 dias prévios à entrevista (sim/não) RP = 1,96 (IC95% 1,23;3,11), número de cômodos no domicílio (1 a 3/4 e mais) RP = 1,67 (IC95% 1,05;2,66), e cor da pele (preta e parda/branca) RP = 2,00 (IC95% 1,14;3,49). CONCLUSÕES: Os achados do presente estudo apontam a importância da asma associada à presença de rinite e alergia, idade entre cinco e nove anos, cor da pele preta e parda e moradia com menor número de cômodos. Os frequentes problemas de saúde podem ser considerados consequência dessa doença.

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A síndrome metabólica (SM) aumenta o risco de eventos cardiovasculares e o consumo adequado de frutas, verduras e legumes (FVL) está relacionado a sua prevenção. Objetivo: Identificar o consumo de FVL e sua relação com a SM e seus componentes em amostra populacional adulta. Estudo prospectivo de corte transversal com 636 indivíduos adultos, no período de 2004 a 2008. Foram realizadas avaliações antropométrica, clínica, dietética e bioquímica com todos participantes. A SM foi classificada pelo NCEP ATP-III, modificada para a glicose >100mg/dl. A regressão logística foi utilizada para verificar a razão de chance entre o consumo de FVL com a SM e seus componentes, e o nível de significância adotado foi de 5%. O consumo de frutas adequado se mostrou protetor para obesidade abdominal (OR: 0,77; IC: 0,38-0,93), hipertrigliceridemia (OR: 0,76; IC: 0,35-0,96) e presença de SM (OR: 0,78; IC: 0,39-0,96), e o consumo adequado de FVL apresentou efeito protetor para a presença de SM (OR: 0,79; IC: 0,41-0,95). A análise isolada do consumo adequado de verduras e legumes não mostrou efeitos de proteção/risco para a presença de SM e de seus componentes. O consumo adequado de FVL apresentou efeito protetor para a presença de SM e o consumo adequado de frutas exerceu efeito protetor tanto para a presença de SM e como de seus componentes.

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O objetivo deste estudo foi avaliar a qualidade global da dieta e a adequação do consumo de cada componente da dieta de adolescentes segundo fatores demográficos, socioeconômicos e índice de massa corporal (IMC). Trata-se de estudo transversal, de base populacional, que analisou amostra representativa de 409 adolescentes, de 12 a 19 anos, utilizando o Índice de Qualidade da Dieta (IQD). Foram estimadas as prevalências de dietas classificadas no 1º quartil do IQD e as médias de escores de cada componente do IQD. Regressões múltiplas linear e de Poisson foram utilizadas nas análises. O escore médio do IQD foi de 59,7. Observou-se menor prevalência de dietas inadequadas no segmento de melhor escolaridade do chefe da família. Os estratos de menor nível socioeconômico, avaliados por renda e escolaridade, mostram um consumo inferior de verduras e legumes, frutas, leite e derivados e menor variedade da dieta e uma ingestão superior de cereais e derivados e leguminosas. Adolescentes com sobrepeso/obesidade consomem mais carnes e ovos e menos frutas comparados aos que apresentam baixo peso/eutrofia. As meninas tiveram maior ingestão de gordura total e menor ingestão de sódio. Os resultados identificam os componentes que merecem atenção nas estratégias de promoção de alimentação saudável e os segmentos mais vulneráveis à má alimentação.

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In this work, the effects of sowing densities on peanut (Arachis hypogaea L.) crop, cv. Tatu were studied. Three experiments were carried out under field conditions on a soil classified as ''Latosol Roxo'', in the Municipality of Pontal, SP, during the wet seasons of 1987-88, 1988-89, and 1989-90. The densities studied were 7, 10, 13, 16, 19, 22, 25, and 28 seeds in one metter of row, under some row spacing of 0.60 m. The pod number per plant was the yield component responsible for the variation of pod production per plant and these decreased with the increase of sowing density. However. The low pod production per plant in high densities of sowing was compensated by the high populations of plants and these produced high yield. Thus, good pod yields were obtained, without significant losses of yield compared with the higher densities, at density of 13 seeds per meter, in 1987-88, 16 seeds per meter in 1988-89 and 10 seeds per meter in 1989-90, that resulted, respectively, in 11.36, 12.72 and 9.28 plants per meter at harvest time.

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The basic knowledge of the seasonal occurrence of mites can supply data for elaboration of programs of ecological management to be implanted with success in the future. The objective of this study was to determine the species richness and the seasonality of mites present in two areas of rubber tree crops neighboring to native areas in Itiquira, MT. Along one year, 25 quantitative samplings were accomplished in rubber tree crop neighboring to two fragments of Cerrado (Cerradao and Mata Riparia). There were registered 199,380 mites, of 48 species, belonging to 15 families. of those, 13 species are phytophagous, 18 predators and 17 mycophagous or of unknown alimentary habit. Three phytophagous species represented more than 97% of the mites collected: Phyllocoptruta seringueirae Feres (80.8%), Tenuipalpus heveae Baker (12.7%) and Calacarus heveae Feres (3.6%). Among the predators, the most abundant species were Agistemus sp., Scirula sp. and Euseius concordis (Chant). Twenty-eight species were common to both crops. The families that had the largest number of species collected in the neighboring area to Cerradao were Tydeidae (7), Tarsonemidae (6), Eriophyidae and Phytoseiidae (4), and in the area close to Mata Riparia, Tydeidae (9) and Phytoseiidae (8). The presence of vegetation near the crop should explain the great number of species of mites classified as accidental found in this study. The largest abundances and species richness occurred in the end of the rainy season and beginning of the dry season.

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Man cultivates the soil for centuries, but the intensive business and use of the soils under Cerrado vegetation for agricultural production grew out of the seventies. The objective of this study was to evaluate soil physical characteristics as a function of sampling time and the soil uses in a Cerrado area in Uberlandia City - MG, Brazil. The managements were adopted: degraded pasture (M-1), conventional tillage (M-2), minimum tillage (M-3), tillage absence (M-4), no-tillage (NT) for three years (M-5); NT for nine years (M-6), NT for three years after Pinus (M-7), PD for one year after Pinus (M-8) and Pinus forest (M-9) with 25 years old. The evaluations were conducted in 2002/03 growing season, in two areas. The soils were: area 1, an Oxisol (Red Latosol - LV-1, M-1 through M-5) and area 2, two Oxisols (Red Latosol and Red-Yellow Latosol - LVA and LV-2, M-6 through M-9). The physical attributes studied changed depending of the soil class, sampling time and management systems, with emphasis on the area 2 soils, which, in general, better preserved its main physical attributes. Managements with intense tillage, such as the M-2, are the most soil physically degrade, presenting mostly negative changes to soil bulk density, total porosity, microporosity and macroporosity. Since the systems which promote less tillage, in short term, to preserve desirable physical attributes. The M-9 system had the lowest attributes range, compared to the others.

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The present study aimed to evaluate the effects of three different stock densities (0.33; 0.67 e 1.00 fish L-1) on freshwater angelfish productive performance reared in aquarium. Fish were fed with commercial diets during 35 days in two diary meals. The experimental design was entirely randomized and for each density were used four replicates. Were evaluated physical-chemical water parameters: temperature, oxygen dissolved concentration and total ammonia concentration and growth performance parameters: weight gain, feed conversion, specific growth rate, final standard length, conduction factor and length uniformity. Results were submitted to variance analysis and means were compared by Tukey's test (alpha = 0.05), it was used the statistic program ESTAT 2.0. Mortality was not observed in any tested density. on physical-chemical water parameters, total ammonia level increased significantly with stock density increasing, but they did not showed clinical signs of ammonia toxicity. As there were no significant differences between treatments, stock density 1.00 fish L-1 is the most indicated because it allows higher production.

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The spittlebugs are considered the most important pests in tropical pastures. The damages caused by these insects decrease the production of pastures. The objective this work was to study the population dynamics of Notozulia entreriana, from June 2007 to June 2008, and the correlation with meteorological and environmental factors (rainfall, temperature, daily solar radiation and pasture height). Therefore, sampled were made in three areas of grassland in the municipality of Marechal Candido Rondon-PR. Sampling of adults and nymphs was made. Also we determined which species of spittlebugs (Hemiptera: Cercopidae) occur in the western region of Parana State. The population fluctuation of N. entreriana showed four peaks during the period of favorable development - spring / summer. The daily solar radiation had a higher correlation with the population. Rainfall, temperature and pasture height had little correlation with the population dynamics. The species that occurred with greater abundance was N. entreriana, representing 88.4% of the total insects collected in western of Parana State.

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Pareiorhina rudolphi was sampled in streams of the Ribeirao Grande system, eastern Serra da Mantiqueira (22[degree]47[minute]08[second]S, 45[degree]28[minute]17[second] W). Samplings were carried out using an electrofishing device, during the months of July/2001, October/2001, February/2002 and April/2002. Sex-ratio diverged significantly from the expected 1: 1 ratio([chi]2 = 6.53; p < 0.05), standing at 1.6:1 (female: male). The spawning period for Pareiorhina rudolphi lasts from spring to summer, with, the highest observed, in October and February by the gonadosomantic index and the relative condition factor coincided with the spawning period. The length at sexual maturity of P. rudolphi is about 4.45 cm for both sexes. The absolute fecundity was low, and ranged from 4 to 11 oocytes. The periphyton was used as a direct food source by the species, which remain attached to the substrate with their large circular lips, and use their conspicuous Slightly Yellowish teeth to graze the periphyton. The growth parameters, natural mortality rate and survival rate for P, rudolphi were respectively: K = 0.35 year-1, L[infinity] = 7.2 cm, tmax = 8.6 years, M = 1.1 year-1, S = 33%. The characteristics presented by P. rudolphi occur in the environment function of a population adjustment, and not of species abundance.

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Population study of white-eared-opossum, Didelphis albiventris (Mammalia, Didelphidae), in a small forest fragment. The white-eared-opossums are habitat generalist animals and occur in high abundance in forest fragments. Therefore these animals are important to understand the dynamics of this landscape. The population of Didelphis albiventris in a 7 ha stational semidecidual forest fragment and its agricultural surroundings was studied during one year. The population abundance, age structure and sex ratio were estimated monthly. Two movements between the fragment and the surrounding area were detected. The population dynamics showed an annual pattern with a high peak during the dry season.

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The objective of this work was to study the population fluctuation of Meloidogyne enterolobii in a commercial orchard of 'Paluma' guava with five years of age, under micro sprinkler irrigation system and usual practices for this crop. In the orchard, located in the municipality of Vista Alegre do Alto (SP) Brazil and infested by M. enterolobii, five plants exhibiting nematode symptoms were selected for monthly sampling from July 2007 to June 2008. Two single samples of rhizosphere soil and guava roots were collected from each plant, with the aid of hoe to a depth of 20 cm on the projection of the trees, forming a composite sample per plant. In nematology laboratory of Faculdade de Ciencias Agrarias e Veterinarias Universidade Estadual Paulista, eggs and second stage juveniles (J2) of M. enterolobii were extracted from the samples and quantified. There was not a marked seasonal variation in the nematode population in soil or roots, possibly as a result of the guava vegetation stimulated by irrigation or the presence of invasive plants during the experimental period. However, the soil density reached a peak in January, corresponding to the month of elevated rainfall and temperatures. In roots, there were two significant peaks, in February and a major peak in August. There was a negative correlation between nematode populations in soil and roots.

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Populational biology of Imparfinis minutus (Siluriformes, Heptapteridae) in the Ribeirao Grande microbasin, eastern Mantiqueira mountain range, São Paulo State. The aim of the work was to analyze biological aspects and distribution of Imparfinis minutus in the Ribeirao Grande microbasin (22[degree]4708[minute]''S, 45[degree]28[minute]17''W), in eastern Mantiqueira mountain range, from July 2001 to April 2002. Among the 37 species sampled, I. minutus (Siluriformes, Heptapteridae), was distributed from the piedmont to the plains of the Vale do Paraiba. The occurrence of this species was associated with the environments of small water volume, bottom with stones and gravel. The amplitude length of I. minutus was 4.75 to 12.75 cm. The length-weight relationship of the population was estimated at W = 0.0052 L3,13. Analyzing the alometric (Ka) and relative (Kr) condition factors, both indexes presented similar values. The lowest value was obtained in July, increasing gradually in October and January, and peaking in April. The analysis of the gonadossomatic relationship (GSR) of females showed higher values in July and January. The reproductive period of I. minutus occurred on spring/summer (October to January), as suggested by the gonadossomatic relationship and condition factor results. Feeding activity was constant, with fat visceral deposition concentrated in April and July. Imparfinis minutus is an aquatic insectivore opportunist species, consuming Diptera and Trichoptera larvae as secondary items. Most ingested food items were autochthonous resources.

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Examines drainage density and networks in terms of methods of calculation, spatial and temporal variability, their relationship with hydrological basins and their paleoclimatic significance.-R.N.Gwynne

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A study was carried out, on both sexes, to determine the effects of chlorpropamide (DIABINESE) and glibenclamide (DAONIL) on patients with Type II diabetes using as metabolic parameters the following serum: glucose, amilase, high density lipoprotein cholesterol, free fatty acids. The results indicated that both drugs were potentially similar in relation to glycemia, high density lipoprotein cholesterol, and free fatty acids, in both sexes. Chlorpropamide was significantly more effective in reducing amilase activity in male diabetics than glibenclamide. The above mentioned hypoglycemiants did not reduce glycemia to basic levels in either masculine or feminine groups of diabetics.