Longitudinal distribution

Top PDF Longitudinal distribution:

The effect of longitudinal distribution and seed depth on grain yield of common bean

The effect of longitudinal distribution and seed depth on grain yield of common bean

In the present experiment, there was also lack of uniformity in hypocotyl diameter, which ranged from 3.38 cm to 8.50 cm (Table 2). In the other characteristics evaluated, there were also big variations: in the number of pods per plant, which ranged from 1 to 19; in the number of seeds per plant, which ranged from 3 to 78; and in grain weight per plant, which ranged from 4.85 g to 110.30 grams. These values indicate that the sowing process was inefficient and brought about significant differences in important characteristics that define crop yield. According to Kachman and Smith (1995), a good acceptable level of precision between maximum and minimum values are variations up to 29%. Based on our results, all the parameters evaluated were higher than this value. One of the factors that may have caused this lack of uniformity in the parameters evaluated is planter adjustment, especially in operating speed. In an evaluation of nine fertilizing planters of maize at three different speeds, Mantovani and Bertaux (1990) found that, in general, longitudinal distribution of seeds was irregular and outside the acceptable limits, tending to become more irregular as forward speed increased. For Delafosse (1986), Kurachi et al. (1989), Garcia et al. (2006), and Santos et al. (2011), operating speed is the variable that most affects planter performance. It affects longitudinal distribution of
Mostrar mais

8 Ler mais

Longitudinal distribution of the ichthyofauna in a tributary of Tieteˆ River with sources on the Basaltic Cuestas of Sa˜o Paulo, Southeastern Brazil

Longitudinal distribution of the ichthyofauna in a tributary of Tieteˆ River with sources on the Basaltic Cuestas of Sa˜o Paulo, Southeastern Brazil

The Cabec¸a River, main tributary of the Passa Cinco River, has an irregular relief with not only rapids but also large waterfalls, consequently hampering the passage of fishes from downstream to upstream. Thus, this physical feature of river drainage may promote a fish distribution different from the expected for rivers in plane areas, where species richness and composition may change gradually toward the mouth. So, an inventory of fish species is presented at different sites of the drainage of the Cabec¸a River aiming to evaluate their longitudinal distribution, and how the local geomorphology may act on the fish communities.
Mostrar mais

8 Ler mais

Repositório Institucional da UFPA: Longitudinal distribution of Chironomidae (Diptera) downstream from a dam in a neotropical river

Repositório Institucional da UFPA: Longitudinal distribution of Chironomidae (Diptera) downstream from a dam in a neotropical river

The damming of a river causes dangerous consequences on structure of the environment downstream of the dam, modi- fying the sediment composition, which impose major adjustments in longitudinal distribution of benthic community. The construction of Engenheiro Sérgio Motta Dam in the Upper Paraná River has caused impacts on the aquatic com- munities, which are not yet fully known. This work aimed to provide more information about the effects of this im- poundment on the structure of Chironomidae larvae assemblage. The analysis of data of physical and chemical variables in relation to biological data of 8 longitudinal sections in the Upper Paraná River showed that composition of Chironomidae larvae of stations near Engenheiro Sérgio Motta Dam differed of the other stations (farther of the Dam). The predominance of coarse sediments at stations upstream and finer sediments further downstream affected the choice of habitat by different morphotypes of Chironomidae and it caused a change in the structure of this assemblage in the longitudinal stretch.
Mostrar mais

10 Ler mais

Longitudinal distribution of Chironomidae (Diptera) downstream from a dam in a neotropical river

Longitudinal distribution of Chironomidae (Diptera) downstream from a dam in a neotropical river

The damming of a river causes dangerous consequences on structure of the environment downstream of the dam, modi- fying the sediment composition, which impose major adjustments in longitudinal distribution of benthic community. The construction of Engenheiro Sérgio Motta Dam in the Upper Paraná River has caused impacts on the aquatic com- munities, which are not yet fully known. This work aimed to provide more information about the effects of this im- poundment on the structure of Chironomidae larvae assemblage. The analysis of data of physical and chemical variables in relation to biological data of 8 longitudinal sections in the Upper Paraná River showed that composition of Chironomidae larvae of stations near Engenheiro Sérgio Motta Dam differed of the other stations (farther of the Dam). The predominance of coarse sediments at stations upstream and finer sediments further downstream affected the choice of habitat by different morphotypes of Chironomidae and it caused a change in the structure of this assemblage in the longitudinal stretch.
Mostrar mais

10 Ler mais

INFLUENCE OF SEED TUBE CURVATURE ON SEED LONGITUDINAL DISTRIBUTION

INFLUENCE OF SEED TUBE CURVATURE ON SEED LONGITUDINAL DISTRIBUTION

1.39, 1.67, 1.94, and 2.22 m s −1 for soybean), with five replications. The parameters analyzed to measure the longitudinal distribution were the number of seeds per meter, average spacing, double, flawed, and acceptable spacings, coefficient of variation, and precision index. The results were subjected to normality and homogeneity tests of residuals, followed by an analysis of variance and Tukey test, when significant. The curved seed tube showed the highest efficiency in the measured parameters for both corn and soybean. The increase in sowing speed had a negative influence on the evaluated parameters, especially in the soybean crop.
Mostrar mais

8 Ler mais

Longitudinal Distribution of Hypostomus punctatus (Osteichthyes, Loricariidae) in a Coastal Stream from Rio de Janeiro, Southeastern Brazil

Longitudinal Distribution of Hypostomus punctatus (Osteichthyes, Loricariidae) in a Coastal Stream from Rio de Janeiro, Southeastern Brazil

The Ubatiba stream is a small coastal stream which has been studied to improve the knowledge of dynamic of fish species and their persistence in unstable environments as this stream. The tropical rains, mainly in summer time, generally cause flash floods which disestablish the habitats, carrying down physical structures (branches, sand, etc), and biotic ones (eggs, larvae, food, etc). In this stream, this phenomenon has been very usual and its fish populations present several tactics to keep themselves alive. In this article, we present the longitudinal distribution of Hypostomus punctatus and its structure in size along the Ubatiba stream.
Mostrar mais

5 Ler mais

Longitudinal distribution and seasonality of macroalgae in a subtropical stream impacted by organic pollution

Longitudinal distribution and seasonality of macroalgae in a subtropical stream impacted by organic pollution

The highest values in species richness found in the middle part of the Cascavel Stream (site P2) are similar to the ones reported by Necchi Jr. and Moreira (1995) in a study of longitudinal distribution of macroalgal communities. In addition, this result is apparently in accordance with the River Continuum Concept (RCC, Vannote et al. 1980) which predicted that richness will be the lowest in headwaters, will increase in the middle parts and will decline in higher-order stretches. However, according to RCC, the prospective increase in richness in P3 was not observed. This fact probably occurred because this sampling site showed the strongest organic pollution level among all stretches investigated, making this stream segment particularly unsuitable for the development of a more diverse community (Necchi Jr. et al., 1994; Branco and Pereira, 2002).
Mostrar mais

9 Ler mais

MANAGEMENT SYSTEMS: SOIL COVER AND COMPACTION, LONGITUDINAL DISTRIBUTION, AND YIELD OF SOYBEAN CROP

MANAGEMENT SYSTEMS: SOIL COVER AND COMPACTION, LONGITUDINAL DISTRIBUTION, AND YIELD OF SOYBEAN CROP

The way the soil is managed can influence its structuring and, consequently, crop yield. Thus, this study aimed to evaluate the effect caused by the management systems plowing followed by two intermediate harrowing operations, intermediate harrowing, chiseling, chiseling followed by intermediate harrowing, cross chiseling followed by intermediate harrowing, and non-tillage on soil and agronomic attributes of the soybean crop. A randomized block design with four replications was used. The percentage of soil cover, soil resistance to penetration, number of plants per meter, longitudinal distribution of seedlings, and soybean yield were evaluated. The data were submitted to analysis of variance by the Tukey test at 5% probability, and use of geostatistics for soil resistance to penetration. The system without soil tillage provides the best straw preservation but affects the longitudinal distribution of soybean seedlings. The use of intermediate harrowing for managing crop residues or soil tillage leads to the greatest compaction problems. Chiseling is efficient in maintaining compaction values below critical values up to a depth of 0.20 m when working at 0.35 m. Soil yield is not affected by soil management systems when the pluviometric regime is adequate to crop requirements.
Mostrar mais

8 Ler mais

FISH ASSEMBLAGE STRUCTURE IN A FIRST ORDER STREAM, SOUTHEASTERN BRAZIL: LONGITUDINAL DISTRIBUTION, SEASONALITY, AND MICROHABITAT DIVERSITY

FISH ASSEMBLAGE STRUCTURE IN A FIRST ORDER STREAM, SOUTHEASTERN BRAZIL: LONGITUDINAL DISTRIBUTION, SEASONALITY, AND MICROHABITAT DIVERSITY

The collection methods of fishes was selected to maxi- mize yield according to the physical characteristics of each stretch of the stream. In the upper stretch two sieves (70 cm in diameter and 2.5 mm mesh) were placed close to the substrate, and the fishes were chased into the sieves over 40 minute period. In the middle and lower stretches of the stream two sieves were employed close to the banks and bottom (40 min- utes), and a manual seine (2 m in length, 1.5 m in height and 2.5 mm mesh) was used in the raceways (20 minutes). Each stretch was blocked by a mesh net (2.5 mm mesh) at its upper end and the fishing operations progressed in an upstream direction. Fishes were immediately preserved in 10% formalin upon cap- ture. The spatial distribution of the fish species in the middle and lower stretches of the stream was observed during 17 hours of snorkelling (13 diurnal and 4 nocturnal), according to the methods “focal animal” and “ad libitum” (Lehner 1998).
Mostrar mais

9 Ler mais

Influence of the riparian zone phytophysiognomies on the longitudinal distribution of fishes: evidence from a Brazilian savanna stream

Influence of the riparian zone phytophysiognomies on the longitudinal distribution of fishes: evidence from a Brazilian savanna stream

The addition of species was the most important process in the downstream reaches (R3 to R5), which is generally the result of increased habitat volume and complexity along the longitudinal gradient of the streams, providing favorable conditions for the occurrence of a greater number of species (Sheldon, 1968; Angermeier & Schlosser, 1989). Nevertheless, the high species richness in upstream reaches, among which 12 were exclusive, and its high dissimilarity in relation to downstream reaches, evidenced by NMDS and SIMPER, also suggests species substitution as an important process in the structuring of fish communities in the Correntes stream. Species substitution is predominant when environmental changes along the longitudinal gradient are sudden, causing physical or biological impediments to ichthyofauna longitudinal colonization (Burton & Odum, 1945; Tramer & Rogers, 1973). In fact, the structural composition of habitats in upstream areas is quite distinct from that of downstream reaches, apparently limiting the occurrence of some species while favoring others. Although physical habitat and physicochemical descriptors varied along the longitudinal gradient of the Correntes stream, the shoreline vegetation was the most important environmental feature predicting fish structure and composition as evidenced by 2Stage analysis and Mantel tests. Structural differences between upstream and downstream reaches correspond to the phytophysiognomy dichotomy observed in the Correntes stream whose shoreline vegetation consists of wet grassland upstream and gallery forest downstream. Wet grasslands are characterized by the dominance of herbaceous and shrubby vegetation adapted to hydromorphic soil (Ribeiro & Water, 1998). In upstream reaches, the small size of the abundantly present shoreline vegetation on the low banks favors their contact with the stream water. Foliage leaning over the channel and roots extending internally increase the spatial heterogeneity of
Mostrar mais

8 Ler mais

SHORT-TERM CHANGES AND LONGITUDINAL DISTRIBUTION OF CARBON METABOLISM IN THE PIAUÍ RIVER ESTUARY (SERGIPE, BRAZIL)

SHORT-TERM CHANGES AND LONGITUDINAL DISTRIBUTION OF CARBON METABOLISM IN THE PIAUÍ RIVER ESTUARY (SERGIPE, BRAZIL)

In a similar way, the CO 2 changes in the free water furnish the “net ecosystem’s metabolism” (NEM; Carmouze, 1994), “whole or total system’s metabolism” (TSM; Nixon & Pilson, 1984)[r]

8 Ler mais

Estudo da capacidade do processo de uma semeadora pneumática analisando a distribuição longitudinal de sementes / Study of process capacity of an air seeder analyzing longitudinal distribution of seed

Estudo da capacidade do processo de uma semeadora pneumática analisando a distribuição longitudinal de sementes / Study of process capacity of an air seeder analyzing longitudinal distribution of seed

semeadora, trabalhando nas velocidades teóricas de 5 km.h -1 e 8 km.h -1 . i Foi utilizado uma semeadora pneumática, pertencente à marca Jumil, cujo modelo é JM2090EX.00. O espaçamento foi ajustado para 6 sementes por metro linear. Na área utilizada demarcou-se 40 m para realizar a distribuição longitudinal das sementes.

7 Ler mais

Autoeficácia de puérperas em amamentar: um estudo longitudinal

Autoeficácia de puérperas em amamentar: um estudo longitudinal

El objetivo de este estudio fue evaluar la auto-eficacia de las mujeres en el período post-parto por su potencial para amamantar. estudio longitudinal de tipo panel. Llevado a cabo en el período comprendido entre mayo diciembre de 2015, el estudio se dividió en cuatro etapas: la primera fue hecha por el contacto directo con puerperal que tuvo lugar en la unidad de alojamiento conjunto (AC) Distrito del Hospital Gonzaga Mota de Messejana, en Fortaleza, Ceará. Los tres contactos posteriores se hicieron por teléfono a través de 2, 4 y 6 meses después del parto. La muestra inicial fue de 66 madres. instrumentos de recolección contemplan la entrega sociodemográficos, obstétricos y corriente y el embarazo. Para evaluar la auto- eficacia de las mujeres se utilizó la Escala de Autoeficacia Escala La lactancia materna - Short Form (SF-BSES). Como resultado se encontró que la mayoría de las mujeres presentan una alta autoeficacia al inicio del estudio (N = 59; 89,4%) y el extremo (N = 27; 96,4%). No había mujeres después del parto con baja auto- eficacia. Se observó una asociación estadísticamente significativa entre todas las variables sociodemográficas y las puntuaciones SF-BSES en todas las fases del estudio. En cuanto a la edad (p = 0,003 para las mujeres de 18-35 años de edad) razas negras y marrones (p = 0,001), tener una pareja (p = 0,013), las mujeres con más de 9 años de estudio (p = 0,026), los ingresos la familia (p = 0,001), propietario de la casa (p = 0,012), salón con capacidad para dos personas (p = 0,001) y el tabaquismo (p = 0,001). Perteneciente a la historia obstétrica se observa asociación estadística entre el número de abortos y la auto-eficacia (p = 0,001), primípara (p = 0,003). La auto-eficacia en la enfermería fue influenciado positivamente por la planificación del embarazo (p = 0,002
Mostrar mais

90 Ler mais

Longitudinal Study of Adult Health

Longitudinal Study of Adult Health

We analyzed baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil 2008-2010; N = 14.378) and data on dietary intake using a food frequency questionnaire, assigning it into three categories: unprocessed or minimally processed foods and processed culinary ingredients, pro- cessed foods, and ultra-processed foods.

6 Ler mais

Imagem corporal de gestantes: um estudo longitudinal.

Imagem corporal de gestantes: um estudo longitudinal.

Como limitações do presente estudo, destacam-se, inicialmente, dois problemas inerentes aos estudos longi- tudinais: o baixo tamanho e a perda amostral. Entretanto, vale ressaltar a dificuldade no recrutamento de grávidas no primeiro trimestre gestacional. Muitas mulheres, ao se des- cobrirem grávidas, encontram-se no segundo trimestre de gestação, o que dificultou o acompanhamento longitudinal delas nos três momentos. Além disso, as perdas da amos- tra foram ocasionadas devido a aborto, parto pré-maturo e ausência nas consultas de pré-natal em algum dos três momentos. Ambas as limitações apontam que os achados do presente estudo não devem ser generalizados. Sugere- -se aos pesquisadores interessados no tema que procurem avaliar longitudinalmente um maior número de gestantes.
Mostrar mais

8 Ler mais

sete anos de estudo longitudinal :: Brapci ::

sete anos de estudo longitudinal :: Brapci ::

Nessa escola de ambiente cooperativo os alunos tinham um papel ativo na construção de sua autonomia e das regras coletivas, e as relações de cooperação e de respeito mútuo eram privilegi[r]

12 Ler mais

Habilidades intelectuais de idosos: um estudo longitudinal

Habilidades intelectuais de idosos: um estudo longitudinal

A constatação do envelhecimento da população mundial tem contribuído para o crescimento das pesquisas relacionadas a idosos. Dados indicam que o envelhecimento, ainda que saudável, acarreta um declínio normal no desempenho intelectual. O presente estudo teve por objetivo investigar o desenvolvimento intelectual de idosos em diferentes domínios avaliados pelo WAIS-III. Resultados mostraram que correlações entre idade e desempenho nas habilidades vulneráveis foram negativas e as correlações apresentadas pelas habilidades estáveis foram positivas. Embora nem todas tenham se mostrado estatisticamente significativas, ocorreram nas direções esperadas. A partir de um delineamento longitudinal e de acordo com as características da amostra, os 47 participantes foram divididos em duas faixas etárias: idosos-jovens (até 74 anos) e idosos-idosos (acima de 75 anos). Os resultados mostraram que os idosos-jovens apresentaram ganhos nas habilidades avaliadas, embora em apenas dois índices estes tenham sido significativos. Com relação às capacidades de compreensão verbal e linguagem, os ganhos eram esperados. Já memória, organização perceptual, velocidade de processamento, QI de Execução e Total não se comportaram como a maior parte dos estudos reporta. Resultados para os idosos-idosos estão de acordo com a literatura: habilidades vulneráveis (organização perceptual, aprendizagem, memória, resolução de problemas e velocidade de processamento) tiveram decréscimos após os oito anos entre as avaliações. Embora nem todos os resultados tenham sido significativos, vão em direção aos das pesquisas que definem a idade de declínios significativos após os 75 anos. Duas amostras independentes foram comparadas a fim de verificar indícios de efeitos geracionais. Análises de caráter exploratório foram realizadas e, apesar do curto intervalo entre os anos médios de nascimento, foram encontradas tendências de aumento nos desempenhos dos participantes com mais de 60 anos. Os resultados estão em acordo com os reportados por Flynn (2006). Concluindo, os resultados apresentados mostram que os idosos não apresentaram declínio nas habilidades intelectuais avaliadas até a idade de 74 anos, a partir de quando alguma perda foi encontrada. A única habilidade que apresentou uma queda marcadamente superior foi a velocidade de processamento. Os resultados positivos dos idosos-jovens e os suaves declínios apresentados pelos idosos-idosos não foram suficientes para caracterizar um padrão de declínio geral nos idosos. Outras variáveis além das examinadas aqui podem estar associadas ao padrão encontrado por outros pesquisadores. Novas pesquisas seriam necessárias para investigá-las e determinar melhor o quanto a idade explicaria a tendência do desenvolvimento intelectual na terceira idade.
Mostrar mais

105 Ler mais

Insatisfação corporal em adolescentes: uma investigação longitudinal.

Insatisfação corporal em adolescentes: uma investigação longitudinal.

Ao contrário do que foi evidenciado para as meninas, no sexo masculino encontraram-se prevalências de insatisfação corporal de 3,7% em T3, 14,6% em T2 e 23,9% em T1, havendo, então, di[r]

5 Ler mais

Atendimento odontológico precoce: estudo longitudinal

Atendimento odontológico precoce: estudo longitudinal

Durante três anos, foram realizadas visitas domiciliares semanais ao Assentamento Bela Vista, zona rural da cidade de Araraquara (SP), onde os cirurgiões-dentistas assistiram crianças [r]

7 Ler mais

Práticas e reflexões de professoras numa pesquisa longitudinal.

Práticas e reflexões de professoras numa pesquisa longitudinal.

A partir da base de dados oferecida pelo Inep sobre as aprendizagens matemáticas de alunos de 4ª série/5º ano, reveladas na Prova Brasil, e dos itens de avaliação disponibilizados para[r]

27 Ler mais

Show all 4012 documents...