Captação de Fucsina ácida em gemas de macieira em diferentes estádios de dormência.

No presente trabalho, avaliou-se a fucsina como indicadora do estádio de dormência, objetivando otimizar um método para aplicação e avaliação do corante nos tecidos, paralelamente com a obtenção de resultados de brotação forçada.Resumo

Expression of dormancy associated mads-box genes in different apple tree organs.

Resumo

Identificação e análise de promotores de desidrinas no genoma da macieira.

Resumo

Chronic central neuropeptide Y infusion in normal rats: status of the hypothalamo-pituitary-adrenal axis, and vagal mediation of hyperinsulinaemia

Summary: Neuropeptide Y in the hypothalamus is a potent physiological stimulator of feeding, and may contribute to the characteristic metabolic defects of obesity when hypothalamic levels remain chronically elevated. Since corticosterone and insulin are important regulators of fuel metabolism, the longitudinal effects of chronic (6 days) intracerebroventricular infusion of neuropeptide Y in normal rats on the hypothalamo-pituitary-adrenal axis and on insulin secretion were studied. Neuropeptide Y-infused rats were either allowed to eat ad libitum, or were pair-fed with normophagic control rats. Neuropeptide Y increased the basal plasma concentrations of adrenocorticotropic hormone and corticosterone during the first 2 days of its intracerebroventricular infusion and increased cold stress-induced plasma adrenocorticotropic hormone concentrations. After 4-6 days of central neuropeptide Y infusion, however, basal plasma adrenocorticotropic hormone and corticosterone concentrations were no different from control values (except in ad libitum-fed rats in which corticosteronaemia remained elevated), they were unaffected by the stress of cold exposure, and the hypothalamic content of corticotropin-releasing factor immunoreactivity was significantly decreased. A state of hyperinsulinaemia was present throughout the 6 days of intracerebroventricular neuropeptide Y infusion, being more marked in the ad libitum-fed than in the pair-fed group. The proportions of insulin, proinsulin, and conversion intermediates in plasma and pancreas were unchanged. Hyperinsulinaemia of the pair-fed neuropeptide Y-infused rats was accompanied by muscle insulin resistance and white adipose tissue insulin hyperresponsiveness, as assessed by the in vivo uptake of 2-deoxyglucose. Finally, bilateral subdiaphragmatic vagotomy prevented both the basal and the marked glucose-induced hyperinsulinaemia of animals chronically infused with neuropeptide Y, demonstrating that central neuropeptide Y-induced hyperinsulinaemia is mediated by the parasympathetic nervous syste

Viewpoint: The Human Capital Approach to Inference

The purpose of this essay is to discuss the “human capital” approach to inference. Observed decisions by experts can be used to organize data on their decisions using simple machine learning techniques. The fact that the human capital of these experts is heterogeneous implies that errors in decision making are inevitable, which in turn allows us to identify the conditional average treatment effect for a wider class of situations than would be possible with randomized control trials. This point is illustrated with some data from medical decision making in the context of treating depression, heart disease, and adverse childbirth events

Determinação da conectividade xilemática em gemas dormentes de Malus × domestica através da aplicação de corante.

A macieira (Malus × domestica Borkh.) caracteriza-se pelo estabelecimento da dormência no outono e a indisponibilidade de água livre nas gemas dormentes. Em regiões onde o acúmulo de frio para quebra de dormência não é suficiente, utilizam-se produtos químicos, como a cianamida hidrogenada (CH) para induzir a saída da dormência e uniformizar a brotação. Uma das dificuldades dos produtores é identificar a melhor época para a aplicação destes produtos químicos. No presente trabalho avaliou-se o transporte de água em gemas apicais durante a dormência, verificando a aplicabilidade da avaliação de padrões de captação de corantes hidrofílicos na estimativa do estádio da dormência. Para tal, foram utilizadas brindilas com gemas apicais fechadas de cultivares contrastantes em requerimento de frio. Em dois experimentos independentes avaliou-se 3 parâmetros: o teor de água, a brotação máxima e a conectividade hídrica em gemas apicais utilizando o corante fucsina ácida. O experimento 1 monitorou esses parâmetros em brindilas amostradas mensalmente no período de 03/2012 a 03/2013 em um pomar da EEFT. No experimento 2 o material vegetal foi brindilas em estádios diferenciados da dormência, com e sem aplicação de CH, mantido em condições ótimas de crescimento. O teor de água e a captação de corante foram maiores em amostras coletadas durante o verão e durante a brotação do que na dormência, e a CH foi capaz de induzir este aumento. Entretanto, não houve diferença entre os estádios de dormência. Os dados mostram maior transporte de água nos tecidos durante o verão e em condições ótimas de crescimento, mas não permitem diferencia r entre gemas endo e ecodormentes e nem estabelecer a fucsina ácida como um marcador para os estádios de dormência. Palavras-Chaves: brindilas, dormência, condutividade hídrica, cianamida hidrogenada, macieira. Temperate fruit trees, such as apple (Malus × domestica Borkh.), are characterized by the establishment of bud dormancy. Bud dormancy is overcome after exposure to a certain amount of chilling hours (under 7,2°C), which varies according to species and cultivars. Another feature of bud dormancy is the lack of free water in buds. In regions where chilling exposure is not enough for dormancy overcoming, applicatio n of chemical substances is necessary in order to break dormancy and for even bud break. One of the difficulties faced by growers is to identify the proper timing for the application of those chemical products. In this work, the water transport in buds during dormancy was assessed, with the intent of evalua ting the use of patterns of hydrophilic dye uptake as a marker for dormancy status. As plant material, apical twigs of contrasting chilling requirement cultivars were used. 'Castel Gala' which shows low chilling requirement for bud break and 'Gala Standard', a high chilling requirement cultivar. These materials were subjected to two experiments: evaluation of water status in buds harvested monthly in the field and under forcing conditions for bud break. Dy e capitation, water content and maximum bud break of apical buds were evaluated. The conductivity of the hydrophilic dye on dormant buds and stems is shown to be reduced during winter. Water content and dye uptake are higher during summer and after bud outgrowth than during dormancy, an d both increase after hydrogen cyanamide application. However, there was no difference between ecodormant and endodormant buds in relation to water content and conductivity. Keywords: twigs, dormancy, xylem conductivity, hydrogen cyanamide, appl

High angular resolution gravitational wave astronomy

Since the very beginning of astronomy the location of objects on the sky has been a fundamental observational quantity that has been taken for granted. While precise two dimensional positional information is easy to obtain for observations in the electromagnetic spectrum, the positional accuracy of current and near future gravitational wave detectors is limited to between tens and hundreds of square degrees, which makes it extremely challenging to identify the host galaxies of gravitational wave events or to confidently detect any electromagnetic counterparts. Gravitational wave observations provide information on source properties and distances that is complementary to the information in any associated electromagnetic emission and that is very hard to obtain in any other way. Observing systems with multiple messengers thus has scientific potential much greater than the sum of its parts. A gravitational wave detector with higher angular resolution would significantly increase the prospects for finding the hosts of gravitational wave sources and triggering a multi-messenger follow-up campaign. An observatory with arcminute precision or better could be realised within the Voyage 2050 programme by creating a large baseline interferometer array in space and would have transformative scientific potential. Precise positional information of standard sirens would enable precision measurements of cosmological parameters and offer new insights on structure formation; a high angular resolution gravitational wave observatory would allow the detection of a stochastic background and resolution of the anisotropies within it; it would also allow the study of accretion processes around black holes; and it would have tremendous potential for tests of modified gravity and the discovery of physics beyond the Standard Model