Energy balance in irrigated wheat in the Cerrados Region of central Brazil.

Um estudo micrometeorológico para avaliar a demanda hídrica do trigo irrigado foi conduzido nas estacões secas de 1982 e 1983 no Centro de Pesquisa Agrícola dos Cerrados, Brasilia-DF, Brasil. A cultura foi irrigada quando o potencial de água no solo a 5 cm atingiu -60 a -70 J/kg.Durante todo o ciclo da cultura medidas da razão de Bowen foram feitas numa base horaria. A quantidade total de água evapotranspirada durante todo ciclo da cultura e o balanco energético variaram entre os anos devido a advecção regional; em 1982, um ano menos advectivo, a quantidade total de água evapotranspirada foi de 345 mm, sendo 80% da radiação liquida dissipada como calor latente, 13% como calor sensível e 7% como calor do solo apos a cultura ter atingido um Índice de Área Foliar (IAF) de 1.5. Em 1983, quando a advecção foi maior que em 1982, a quantidade total de água evapotranspirada aumentou para 385mm. A partição de energia foi similar a 1982 durante períodos de pouca ou nenhuma advecção. Entretanto durante períodos de intensa advecção, o calor latente representou a maior parte da radiação liquida. Apesar da advecção regional aumentar o consumo de água da cultura, programação da irrigação baseada em tensiômetro foi considerada adequada e eficiente devido aos baixos valores da razão de Bowen obtidos

Energy balance in irrigated wheat in the Cerrados Region of central Brazil.

To evaluate the water requirements for Irrigated wheat, a mlcrometeorological study was conducted during the dry seasons of 1982 and 1983 at the Cerrados Agricultural Research Center, Brasilia-DF, BraziL The crop was Irrigated when the soU water potential at 5 cm reached-60 to -7OJIkg. Bowen ratio measurements were made on an hourly basls during the entire crop season, Total amount of water evapotranspired during the crop cycle and the energy balance terms varied year to year due to regional advection; ln 1982,a Iess advective year, the total amount of water evapotranspired was 345 mm, with approximately 80% of the net radlation dlsslpated as latent heat, 13% as a sensible heat and 7% as soU heat after the crop obtalned a Leaf Area lndex (LAI) of 1.5. ln 1983, when advection was greater than 1982, total water evapotranspired Increased to 385mm. The partitloning of energy was similar to 1982 during periods of title or no advecnon, However, during periods of Intense advection, latent heat was greater. In net radlation partitioning. Although regional advection Increased the water used by the crop, Irrigation scheduling based on soíl tensiometers was considered adequate and eflicient due to the low values of the Bowen ratio obtalned. Um estudo núcrometeorológico para avaliar a demanda hídrica do trigo Irrigado foi conduzido nasestações secas de 1982 e 1983 no Centro de Pesquisa Agricola dos Cerrados, Brasilia-DF, Brasil A cultura foi Irrigada quando o potencial de água no solo a 5 cm atinriu -60 a -70 JIkg. Durante todo o ciclo da cultura medidas da razão de Bowen foram feitas numa base horária. A quantidade total de água evapotranspirada durante todo ciclo da cultura e o balanço energético variaram entre os anos devido à advecção regional; em 1982, um ano menos advectivo, a quantidade total de água evapotranspirada foi de 345 mm, sendo 80% da radiação líquida dissipada como calor latente, 13% como calor sensível e 7% como calor do solo após a cultura ter atingido um Índice de Área Foliar (IAF) de 1.5. Em 1983, quando a advecção foi maior que em 1982, a quantidade total de água evapotranspirada aumentou para 385 mm. A partição de energia foi similar à 1982 durante periodos de pouca ou nenhuma advecção. Entretanto durante periodos de Intensa advecção, o calor latente representou a maior parte da radiação líquida. Apesar da advecção regional aumentar o consumo de água da cultura, programação da irrigação baseada em tensiometros foi considerada adequada e eficiente devido aos baixos valores da razão de Bowen obtidos.Nº especial

Short communication: Polymorphism of casein cluster genes in Czech local goat breeds

The 4 casein loci were evaluated as haplotypes in 2 dairy goat breeds kept in the Czech Republic. Analysis of 41 White Shorthaired (WSH) trio families and 44 Brown Shorthaired (BSH) trio families revealed 14 and 20 haplotypes, respectively. Various genomic techniques were used to type the casein loci. Twenty-two different combinations of these alleles (casein haplotypes, in the order CSN1S1-CSN2-CSN1S2-CSN3) were found. Only 5 haplotypes in the WSH breed and 6 haplotypes in the BSH breed occurred at frequencies >0.05. For the WSH breed, the most common haplotype was FCFB (0.260), whereas for the BSH breed, the most common haplotype was FCFA (0.217). The information on the haplotype variability in both breeds could be used in breeding programs aimed at preserving biodiversity or selecting animals for specific protein production and cheesemaking

Probabilistic Modeling of Space Shuttle Debris Impact

On Feb 1, 2003, the Shuttle Columbia was lost during its return to Earth. As a result of the conclusion that debris impact caused the damage to the left wing of the Columbia Space Shuttle Vehicle (SSV) during ascent, the Columbia Accident Investigation Board recommended that an assessment be performed of the debris environment experienced by the SSV during ascent. A flight rationale based on probabilistic assessment is used for the SSV return-to-flight. The assessment entails identifying all potential debris sources, their probable geometric and aerodynamic characteristics, and their potential for impacting and damaging critical Shuttle components. A probabilistic analysis tool, based on the SwRI-developed NESSUS probabilistic analysis software, predicts the probability of impact and damage to the space shuttle wing leading edge and thermal protection system components. Among other parameters, the likelihood of unacceptable damage depends on the time of release (Mach number of the orbiter) and the divot mass as well as the impact velocity and impact angle. A typical result is visualized in the figures below. Probability of impact and damage, as well as the sensitivities thereof with respect to the distribution assumptions, can be computed and visualized at each point on the orbiter or summarized per wing panel or tile zone

Urbanicity and lifestyle risk factors for cardiometabolic diseases in rural Uganda: a cross-sectional study

Urban living is associated with unhealthy lifestyles that can increase the risk of cardiometabolic diseases. In sub-Saharan Africa (SSA), where the majority of people live in rural areas, it is still unclear if there is a corresponding increase in unhealthy lifestyles as rural areas adopt urban characteristics. This study examines the distribution of urban characteristics across rural communities in Uganda and their associations with lifestyle risk factors for chronic diseases

Carbon, nutrient, light interception and soil water dynamics of secondary forests and agroforestry systems on degraded pastures.

In the Brazilian Amazon, primary forest and degraded pastures represent polar extremes of carbon stocks, nutrient cycling, light interception, and deep soil water cycling. Plant succession on degraded pastures is expected to change these values, and the extent to which secondary forest (SF) restores these processes is a high priority research objective

Temperature and soil water status effects on radiation use and growth of pearl millet in a semi-arid environment

In semi-arid environments, crops are frequently subjected to a combination of high air temperatures, large atmospheric saturation vapor pressure deficits, high soil temperatures and reduced soil water status. To explore the performance of pearl millet (Pennisetum typhoides S. and H., cv. CIVT) from panicle initiation to flowering (GS 2) when grown in the field under combinations of these conditions, experiments were conducted in northern Nigeria in three seasons in which daily mean air temperatures during 18 days of this stage averaged 22, 27 and 33°C, and saturation vapor pressure deficits averaged 3.7, 4.0 and 5.2 kPa, respectively. In each experiment, half of the crop was irrigated, while the other half received no water after panicle initiation. For irrigated millet, radiation use efficiency (RUE) did not vary significantly (P = 0.05) for the three experiments (1.7 g MJ−1). RUE of non-irrigated millet was significantly reduced (0.8 g MJ−1) only during the season with the highest temperature. Radiation interception as a function of thermal time was similar in the irrigated and non-irrigated treatments except in the season with the highest temperatures, when radiation interception was reduced about 25% in the non-irrigated relative to the irrigated treatment. Stem extension of non-irrigated millet did not decline relative to irrigated millet, despite the almost complete extraction of plant available water in the upper 30 cm of the soil, except during the season with the highest temperatures, when stem extension rates began to decline as soon as water was withheld. Under high air temperatures and saturation vapor pressure deficits, dry matter accumulation in both irrigated and non-irrigated millet during GS 2 could be reasonably predicted from RUE and radiation interception. However, when high soil temperatures (daily mean at 5 cm of 34°C) occurred in the non-irrigated treatment, both RUE and radiation interception decreased relative to all other treatment

Water uptake by pearl millet in a semiarid environment

Crops during drought may not utilize water at depth. This under-utilization of deep water may result from slow rates of root extension, low root density, or a decline in soil water potential or associated phenomena. The importance of several of these factors on pearlmillet (Pennisetum glaucum (L.) R. Br., cv. CIVT) wateruptake and growth from panicle initiation to flowering was studied on a sandy soil in northern Nigeria during two dry seasons. Half of the crop was irrigated while the other half received no water after panicle initiation. Soil water content, stomatal conductance and stem extension were measured periodically. A potential-driven wateruptake model, which assumes a static, exponential distribution of roots and couples transpiration to leaf water potentials, described in both seasons the observed pattern and timing of wateruptake, as well as predawn leaf water potential and actual transpiration. As the soil dried, estimated transpiration declined below potential transpiration and modeled and measured predawn leaf water potential declined. There was close agreement between observed and modeled predawn leaf water potential and soil wateruptake. Analysis using the model indicated that decreased wateruptake at depth was attributable to root distribution throughout the soil profile, as well as to low root length density at dept

Prospective Trial of CPAP in Community-Dwelling Adults with Down Syndrome and Obstructive Sleep Apnea Syndrome

Adults with Down syndrome (DS) are predisposed to obstructive sleep apnoea (OSA), but the effectiveness and acceptability of continuous positive airway pressure treatment (CPAP) in this group has rarely been formally assessed. This study was designed as a pilot randomised, parallel controlled trial for one month, continuing as an uncontrolled cohort study whereby the control group also received the intervention. Symptomatic, community-dwelling DS individuals exhibiting ≥10 apnoeas/hypopneas per hour in bed on a Type 3 home sleep study were invited to participate in this study, with follow-up at 1, 3, 6, and 12 months from baseline. Measurements of sleepiness, behaviour, cognitive function and general health were undertaken; the primary outcome was a change in the pictorial Epworth Sleepiness Scale (pESS) score. Twenty-eight participants (19 male) were enrolled: age 28 ± 9 year; body mass index 31.5 ± 7.9 kg/m2; 39.6 ± 32.2 apnoeas/hypopneas per hour in bed; pESS 11 ± 6/24. The pilot randomised controlled trial at one month demonstrated no change between the groups. At 12 months, participant (p = 0.001) pESS and Disruptive (p 0.0001), Anxiety/Antisocial (p = 0.024), and Depressive (p = 0.008) behaviour scores were reduced compared to baseline. Improvement was noted in verbal (p = 0.001) and nonverbal intelligence scores (p = 0.011). General health scores also improved (p = 0.02). At the end of the trial, 19 participants continued on treatment. Use of CPAP in adults with DS and OSA led to a number of significant, sustained improvements in sleepiness and behavioural/emotional outcomes at 12 months