Absorção de nutrientes pelo tomateiro cultivado sob condições de campo e de ambiente protegido Nutrient absorption by tomato plants grown under field and protected conditions

Foram realizados dois experimentos, na Universidade Federal de Viçosa, objetivando caracterizar a absorção de nutrientes pelo tomateiro cultivado sob condições de campo e de ambiente protegido. O primeiro, com a cultivar Santa Clara, cultivada a campo, no sistema de cerca cruzada e sete cachos. O segundo, em estufa plástica, com o híbrido EF-50, conduzidas verticalmente, mantendo-se oito cachos em cada uma. Ambos experimentos foram delineados em blocos ao acaso, com quatro repetições. O primeiro constituído por oito e o segundo por nove tratamentos. Em ambos experimentos, o padrão de absorção de nutrientes seguiu o acúmulo de matéria seca pelas plantas. No experimento de campo, a ordem decrescente de acúmulo de nutrientes na parte aérea foi: K, N, Ca, S, P, Mg, Cu, Mn, Fe e Zn, alcançando os valores máximos de 360; 206; 202; 49; 32; 29 kg.ha-1; 3.415; 2.173; 1.967 e 500 g.ha-1, respectivamente. Em ambiente protegido, o acúmulo de nutrientes na parte aérea do tomateiro decresceu na seguinte ordem: K, N, Ca, S, Mg, P, Mn, Fe; Cu e Zn, alcançando os valores de 264; 211; 195; 49; 40; 30 kg.ha-1; 3.200; 2.100; 1.600 e 700 g.ha-1, respectivamente. As taxas de absorção diária dos nutrientes são apresentadas bem como as porcentagens de absorção do N e de K em determinados períodos do crescimento do tomateiro, visando auxiliar na programação das épocas de aplicação destes nutrientes em cobertura.<br>Two experiments were conducted at Universidade Federal de Viçosa to evaluate nutrient absortion by tomato plants grown under field and protected conditions. In the first experiment, tomato cv. Santa Clara was grown in the field with seven clusters/plant. In the second one tomato hybrid EF-50 was grown in plastic greenhouse and pruned to eight clusters. Both experiments were designed as randomized blocks, with four replicates. The first and second experiments were performed with eight and nine treatments, respectively. In both experiments, the nutrient absorption patterns followed the plant dry matter accumulation. In the field experiment, the amounts of nutrient uptaken by the plants decreased following the order K, N, Ca, S, P, Mg, Cu, Mn, Fe and Zn reaching their maximal values of 360; 206; 202; 49; 32; 29 kg ha-1; and 3415; 2173; 1967 and 500 g ha-1, respectively. In the greenhouse experiment, the order was K, N, Ca, S, Mg, P, Mn, Fe, Cu, and Zn reaching their maximal values of 264; 211; 195; 49; 40; 30 kg ha-1; and 3227; 2121; 1639 and 651 g ha-1, respectively. Nutrient daily absorption rates are presented as well as the percentages of N and K uptaken at determined tomato plant growth period, which can be helpful to program the time of sidedressing of those nutrients

Molecular mechanisms and biological role of Campylobacter jejuni attachment to host cells.

Adhesion to host cells is an important step in pathogenesis of Campylobacter jejuni, which is the most prevalent bacterial cause of human gastroenteritis worldwide. In contrast to other bacteria such as E. coli and Salmonella, adherence of C. jejuni is not mediated by fimbria or pili. A number of C. jejuni adhesion-related factors have been described. However, the results obtained by different researchers in different laboratories are often contradictory and inconclusive, with only some of the factors described being confirmed as true adhesins. In this review, we present the current state of studies on the mechanisms of attachment of C. jejuni to host cells

Seasonal Production and Biomass of the Seagrass, Halodule wrightii Aschers. (Shoal Grass), in a Subtropical Texas Lagoon

A study of Halodule wrightii in a shallow subtropical Texas lagoon was performed to obtain seasonal data on its physiological ecology. Leaf production and biomass dynamics of H. wrightii were intensively monitored along with the underwater light environment at a 1.2-m depth study site over a 21-month period from June 1995 to February 1997. The annual photosynthetically active radiation (PAR) flux of 6,764 mol m−2 year−1 was more than twice as high as 2,400 mol m−2 year−1, the minimum annual PAR required for maintenance of growth. As light intensity declined, blade chlorophyll a/b ratios increased suggesting that the plants were photo-adapting. Seasonal trends were evident in shoot growth and biomass. Compared to other Halodule populations in Texas, H. wrightii in LLM displayed slow growth and low biomass, high leaf tissue N content, and low C/N ratio but high N/P ratio of 38 suggesting that the plants were phosphorus-limited

The CHEOPS mission

The CHaracterising ExOPlanet Satellite (CHEOPS) was selected in 2012, as the first small mission in the ESA Science Programme and successfully launched in December 2019. CHEOPS is a partnership between ESA and Switzerland with important contributions by ten additional ESA Member States. CHEOPS is the first mission dedicated to search for transits of exoplanets using ultrahigh precision photometry on bright stars already known to host planets. As a follow-up mission, CHEOPS is mainly dedicated to improving, whenever possible, existing radii measurements or provide first accurate measurements for a subset of those planets for which the mass has already been estimated from ground-based spectroscopic surveys and to following phase curves. CHEOPS will provide prime targets for future spectroscopic atmospheric characterisation. Requirements on the photometric precision and stability have been derived for stars with magnitudes ranging from 6 to 12 in the V band. In particular, CHEOPS shall be able to detect Earth-size planets transiting G5 dwarf stars in the magnitude range between 6 and 9 by achieving a photometric precision of 20 ppm in 6 hours of integration. For K stars in the magnitude range between 9 and 12, CHEOPS shall be able to detect transiting Neptune-size planets achieving a photometric precision of 85 ppm in 3 hours of integration. This is achieved by using a single, frame-transfer, back-illuminated CCD detector at the focal plane assembly of a 33.5 cm diameter telescope. The 280 kg spacecraft has a pointing accuracy of about 1 arcsec rms and orbits on a sun-synchronous dusk-dawn orbit at 700 km altitude. The nominal mission lifetime is 3.5 years. During this period, 20% of the observing time is available to the community through a yearly call and a discretionary time programme managed by ESA

GA4GH: International policies and standards for data sharing across genomic research and healthcare.

The Global Alliance for Genomics and Health (GA4GH) aims to accelerate biomedical advances by enabling the responsible sharing of clinical and genomic data through both harmonized data aggregation and federated approaches. The decreasing cost of genomic sequencing (along with other genome-wide molecular assays) and increasing evidence of its clinical utility will soon drive the generation of sequence data from tens of millions of humans, with increasing levels of diversity. In this perspective, we present the GA4GH strategies for addressing the major challenges of this data revolution. We describe the GA4GH organization, which is fueled by the development efforts of eight Work Streams and informed by the needs of 24 Driver Projects and other key stakeholders. We present the GA4GH suite of secure, interoperable technical standards and policy frameworks and review the current status of standards, their relevance to key domains of research and clinical care, and future plans of GA4GH. Broad international participation in building, adopting, and deploying GA4GH standards and frameworks will catalyze an unprecedented effort in data sharing that will be critical to advancing genomic medicine and ensuring that all populations can access its benefits

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions. © Copyright