Risk, Resilience, and Success in College for Students with Vision Disabilities

College students with visual disabilities are less likely to graduate than their sighted counterparts. The purpose of this study was to understand the life experiences of successful college students with visual disabilities. Concepts of risk and resiliency were used as a conceptual framework for understanding how people can have positive outcomes in spite of adversity. Individual, family, school, and community influences were explored. In-depth interviews were conducted with six participants who have vision impairments and were nearing the completion or had recently completed a college degree. Data were analyzed for common themes and meanings using a phenomenological method advanced by Moustakas (1994). Validity threats were minimized through triangulation, member checks, and thick data. Risk and protective factors in the context of family, school, and community for successful college students with visual disabilities were identified. Implications for rehabilitation counselors, college counselors, and special education teachers were discussed. Interventions to move students with visual disabilities toward resiliency and minimize the impact of risk factors that impede success were proposed. Suggestions for future research were offered

Risk, Resilience, and Success in College for Students with Vision Disabilities

College students with visual disabilities are less likely to graduate than their sighted counterparts. The purpose of this study was to understand the life experiences of successful college students with visual disabilities. Concepts of risk and resiliency were used as a conceptual framework for understanding how people can have positive outcomes in spite of adversity. Individual, family, school, and community influences were explored. In-depth interviews were conducted with six participants who have vision impairments and were nearing the completion or had recently completed a college degree. Data were analyzed for common themes and meanings using a phenomenological method advanced by Moustakas (1994). Validity threats were minimized through triangulation, member checks, and thick data. Risk and protective factors in the context of family, school, and community for successful college students with visual disabilities were identified. Implications for rehabilitation counselors, college counselors, and special education teachers were discussed. Interventions to move students with visual disabilities toward resiliency and minimize the impact of risk factors that impede success were proposed. Suggestions for future research were offered

Variabilidade diária da chuva em uma escala local (1000 ha) em Piracicaba, SP, e suas implicações na recarga da água do solo

Daily rainfall variability at a local scale (1,000 ha) was studied at Piracicaba, SP, Brazil, for the period of one year (1993-1994), in order to better understand the process of soil water recharge. Coefficients of variation of daily data for ten observation points varied from 2.2 to 169.3% and the variability was independent of rain type, i.e. whether convective, frontal or of other origin. Data were not related to separation distances between observation points and it is concluded that one observation point does not represent areas as far as 1,000 to 2,500 m apart, for daily, monthly or even quarterly averages. Yearly totals for the ten observation points presented a coefficient of variation as low as 3.06%, indicating that all points can replace each other in annual terms.A variabilidade diária da chuva em uma escala local (1000 ha) foi estudada em Piracicaba, SP, Brasil, pelo período de um ano (1993-1994). Os coeficientes de variação de dados diários para dez pontos de observação variaram de 2,2 a 169,3 % e a variabilidade independeu do tipo de chuva, isto é, se convectiva, frontal ou de outra origem. Os dados não apresentaram correlação com a distância entre os pontos de observação e concluiu-se que uni ponto de observação não representa áreas distantes dele de 1000 a 2500 m, para médias diárias, mensais ou mesmo trimestrais. Os totais anuais dos dez pontos apresentaram um coeficiente de variação de apenas 3,06 %, indicando que cada ponto pode representar qualquer outro em termos anuais

Preliminary evaluation of sap flow data by stem heat balance method.

Cermak et al. (1973) developed the first version of the heat balance method (HBM), which involves continuous application of heat in a stem segment and quantifying losses by axial and radial wood conduction. The heat flow carried out by the sap is determined from the difference between input power and axial and radial heat losses from the heated stem segment. Currently, this method follows Sakuratani (1981) and Baker & Van Bavel (1987), who modified the first HBM version by applying a constant power on the gauge, so reducing the electronic requirements for the measurements. The HBM is an absolute method that requires simple equipment and some basic procedures in order to minimize errors (Baker & Nieber, 1989; Steinberg et al., 1990; Valancogne & Nasr, 1993; Weibel & de Vos, 1994). However, it is difficult to evaluate sap flow measurements in field conditions since reference methods, such as lysimeters, soil water balance and other techniques are normally difficult to apply, especially for big plants. This paper focuses on this problem and considers some procedures to evaluate data supplied by HBM when reference methods are not available

Evapotranspiration and CROP COEFFICIENTS of a Coffee Plantation in Southern Brazil.

Coffee plants have been cultivated in Brazil since 1727 and have a great importance for the economy of the country. Brazil has more than 2,400,000 ha of commercial plantations of coffee, and in the last 15 years they have been expanded to regions where drought is more intense and normally coincides with fruit expansion, what became irrigation very important and somewhat essential in such regions (Camargo, 1985). Currently, it is estimated that about 200,000 ha of coffee plantations are being grown under irrigation in the country. In spite of great advances in technologies for water supply and the economic importance of coffee crop, irrigation management have been made inadequately in the most Brazilian coffee regions due to the large amount of water applied, which normally exceeds the crop needs (Camargo, 2002). Regarding this point, Carr (2001) postulated that estimates of water requirements for irrigation purposes are still imprecise for this crop and, probably, subject to large errors depending on the local circumstances and the system of irrigation used. The objective of this study was to assess the water use by a drip-irrigated coffee plantation in Southern Brazil using different measurement techniques in order to determine the two components of crop coefficients (Kc), i.e. basal (Kcb) and evaporative (Kce) components. The study also evaluated the micrometeorological factors affecting transpiration, crop and reference evapotranspiration relationships and its implications on actual rates of water use and on irrigation management

Microclimatologia de cafezais adensados: bases para a modelagem do consumo hídrico e do balanço de radiação.

Modelo de Penman-Monteith adaptado à estimativa da transpiração individual de lenhosas. Aspectos ecofisiológicos da cultura do cafeeiro. Transpiração e evapotranspiração de cafezais. Métodos micrometeorológicos de determinação da evapotranspiração. Estimativa da evapotranspiração de cafezal em crescimento pelos métodos aerodinâmico e da razão de Bowen. Modelo de Penman-Monteith adaptado à estimativa da transpiração individual de lenhosas. Absorção de energia radiante. Estimativa da transpiração máxima de cafeeiros pelo modelo de Penman-Monteith adaptado a plantas isoladas: um estudo de caso. Estimativa da evapotranspiração de referência. Relação entre a transpiração dos cafeeiros e a evapotranspiração de referência e a do cafezal.bitstream/item/61082/1/livro-doc-118.pd

Padrões de interceptação de radiação solar por cafeeiros em função da área foliar

The study evaluated solar radiation interception patterns (K*) defining the relations of interception efficiency (εint) and extinction coefficient (k) of coffee trees (cv. Obatã IAC 1669-20) under leaf area changes. Aiming to determine these interactions for coffee plants (3 years old) under manual defoliations, solar radiation transmitted was measured with two tube solarimeters placed at ground level below the crowns. A canopy-light interception model was derived using the extinction coefficient approach (Monsi & Saeki theory) to assess with independent data to estimate K*. Under absence of leaves, an intense interference of leaves supporting structures over εint was observed, with a minimum value of 0.34. The results were also distinct for obtaining k. The derived model well simulated the K* against measurements, with Willmott index as high as 0.92, improving modeling accuracy using ‘k’ from quadratic fit.Objetivou-se, no presente trabalho, avaliar alterações nos padrões de interceptação de radiação solar pela copa de cafeeiros, em consequência da variação do índice de área foliar por desfolhas, determinando-se relações da eficiência de interceptação e do coeficiente de extinção da radiação da copa, com a variação de área foliar. Adicionalmente, estimar a radiação solar interceptada pelos cafeeiros e comparar a valores medidos por radiometria. O mesmo modelo teórico usado para determinar o coeficiente de extinção ‘k’ (Teoria de Monsi & Saeki) foi usado, também, para a estimativa da radiação solar interceptada (K*). Os dados revelaram uma clara interferência das estruturas de sustentação das folhas, sobre a eficiência de interceptação da radiação solar (εint), com valor mínimo de 0,34 com ausência completa de folhas. Os resultados também foram distintos, em relação à obtenção do coeficiente de extinção ‘k’, mais uma vez com influência do tronco e ramos plagiotrópicos. As simulações de K* confrontadas às medições apresentaram boa correlação, tanto na escala de 15 min, como diária. Conforme o índice de Willmott (d), o uso do coeficiente k obtido por ajuste quadrático tornou as estimativas mais exatas

Balanço de radiação de renques de cafeeiros

The radiation balance of hedgerows is an important variable in studies of mass and energy exchanges between parcial ground cover crops and the atmosphere. This paper describes a device with eight net radiometers encompassing the plants of a hedgerow. The radiometers were moved along a length of hedgerow, in a continuous and reversible movement. The canopy net radiation in this length (Rnc) was found by integration of the measurements over the notional cylinder formed. The device showed good performance and provided reliable measurements of Rnc of coffee hedgerows, showing itselfto be an useful technique of measurement in field conditions. Good correlations between Rnc and global solar radiation, turfgrass and coffee crop net radiation were found in 15-min, daytime and 24-hr periods, allowing the possibility of estimating Rnc from these simple measurements. Beer’s law was also used to have an independent estimation of Rnc. A good agreement was found between values of Rnc estimated by this law of attenuation and those integrated by the device in periods of 15 min, with overestimation of 10%, whereas for values integrated over daytime periods the agreement was not satisfactory.A radiação, tanto de ondas curtas como de ondas longas, absorvida por um renque de plantas de uma cultura que cobre de forma descontínua o solo, é uma variável importante para os estudos das trocas de massa e de energia com a atmosfera. Este trabalho apresenta um dispositivo que movimenta oito saldo-radiômetros dispostos em torno de um renque. O movimento de ida e volta ao longo de um trecho de um renque, permite a integração do saldo de radiação na superfície de um cilindro nocional de medidas, representando o balanço de radiação (Rnc) do trecho amostrado. O equipamento apresentou um bom desempenho quando empregado em dois cafezais, mostrando potencial para a realização de medidas de campo, com valores medidos confiáveis. Foram obtidas boas correlações entre Rnc e a irradiância solar global e, também, entre Rnc e o saldo de radiação medido sobre gramado e sobre o cafezal, para dados obtidos em intervalos de 15 minutos, diurnos e diários. Uma adaptação da Lei de Beer também foi avaliada para modelagem de Rnc, resultando valores superestimados em 10% em relação aos valores integrados em 15 minutos pelo dispositivo móvel , mas para os integrados no período diurno a concordância entre dados estimados e medidos não foi boa.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPqCoordenação de Aperfeiçoamento do Pessoal de Nível Superior (CAPES

Irrigation requirements and transpiration coupling to the atmosphere of a citrus orchard.

Crop evapotranspiration (ETc) was measured as evaporative heat flux from an irrigated acid lime orchard (Citrus latifolia Tanaka) using the aerodynamic method. Crop transpiration (T) was determined by a stem heat balance method. The irrigation requirements were determined by comparing the orchard evapotranspiration (ETc) and T with the reference evapotranspiration (ETo) derived from the Penman-Monteith equation, and the irrigation requirements were expressed as ETc/ETo (Kc) and T/ETo (Kcb) ratios. The influence of inter-row vegetation on the ETc was analyzed because the measurements were taken during the summer and winter, which are periods with different regional soil water content. In this study, the average Kc values obtained were 0.65 and 0.24 for the summer and winter, respectively. The strong coupling of citrus trees to the atmosphere and the strong coupling of the sensitivity of citrus plants to large vapor pressure deficits and air/leaf temperatures caused variations in the Kcb in relation to the ETo ranges. During the summer, the Kcb value ranged from 0.34 when the ETo exceeded 5 mm d-1 to 0.46 when the ETo was less than 3 mm d-1.CBA 2011