Seasonal variation of water uptake of a Quercus suber tree in Central Portugal

Hydraulic redistribution (HR) is the phenomenon where plant roots transfer water between soil horizons of different water potential. When dry soil is a stronger sink for water loss from the plant than transpiration, water absorbed by roots in wetter soil horizons is transferred toward, and exuded into dry soil via flow reversals through the roots. Reverse flow is a good marker of HR and can serve as a useful tool to study it over the long-term. Seasonal variation of water uptake of a Quercus suber tree was studied from late winter through autumn 2003 at Rio Frio near Lisbon, Portugal. Sap flow was measured in five small shallow roots (diameter of 3–4 cm), 1 to 2 m from the tree trunk and in four azimuths and at different xylem depths at the trunk base, using the heat field deformation method (HFD). The pattern of sap flow differed among lateral roots as soil dried with constant positive flow in three roots and reverse flow in two other roots during the night when transpiration ceased. Rain modified the pattern of flow in these two roots by eliminating reverse flow and substantially increasing water uptake for transpiration during the day. The increase in water uptake in three other roots following rain was not so substantial. In addition, the flux in individual roots was correlated to different degrees with the flux at different radial depths and azimuthal directions in trunk xylem. The flow in outer trunk xylem seemed to be mostly consistent with water movement from surface soil horizons, whereas deep roots seemed to supply water to the whole cross-section of sapwood. When water flow substantially decreased in shallow lateral roots and the outer stem xylem during drought, water flow in the inner sapwood was maintained, presumably due to its direct connection to deep roots. Results also suggest the importance of the sap flow sensor placement, in relation to sinker roots, as to whether lateral roots might be found to exhibit reverse flow during drought. This study is consistent with the dimorphic rooting habit of Quercus suber trees in which deep roots access groundwater to supply superficial roots and the whole tree, when shallow soil layers were dry

Impact of primary and secondary machinery tracks on fine root growth of sugar maple after selection cutting

Selection cutting, where approximately 30% of the trees are removed every 30 years, is the main silvicultural treatment used in temperate deciduous forests of Quebec (Canada). Concerns have been raised that the use of heavy machinery is creating soil disturbances that are negatively affecting the growth and survival of remaining trees. The aim of the study was to determine if heavy machinery is affecting the growth, morphology, and architecture of sugar maple (Acer saccharum Marsh.) fine roots in and around machinery tracks left after selection logging. The study site, a sugar maple dominated stand, was located in southern Quebec. Root ingrowth bags and standard root cores were used to compare fine root growth, morphology, and architecture in and around machinery tracks one year after logging. Fine root growth of maple was reduced fivefold in both primary (multiple trip) and secondary (only one trip) machinery tracks compared with the control. There was a nonstatistical reduction in fine root growth within 1 m of the tracks. Because machinery tracks cover between 15% and 25% of a stand after selection logging, such reduction in fine root growth could be significant for the growth and survival of the remaining mature maple trees

Pleiotropic effects of erythropoietin. Influence of erythropoietin on processes of mesenchymal stem cells differentiation

The article notes that рuman recombinant erythropoietin is characterised as a factor which stimulates differentiation and proliferation of erythroid precursor cells, and as a tissue protective factor. Erythropoietin is one of the most perspective humoral agents which are involved in the preconditioning phenomeno

Pharmacological modulation of cell functional activity with valproic acid and erythropoietin

Valproic acid (VA) is carboxylic acid with a branched chain, which is used as an antiepileptic drug. VA, which is an antiepileptic drug, is also a teratogen, which causes defects of a neural tube and an axial skeleton, although the mechanisms are not yet fully clear. It is shown that valproic acid reduces the intracellular level of oxygen active form

МЕТОДИКА ОЦЕНКИ СБАЛАНСИРОВАННОСТИ РЕГИОНАЛЬНОГО ПРОДОВОЛЬСТВЕННОГО РЫНКА

Author’s approach is proposed to forecast averaged per capita production and solvent demand for primary food stuffs. The approach provides balanced regional food market, selects adequate models to forecast demand and supply of the food stuffs in Novosibirsk region for the period 2013–2015. The paper interpretes the balance of regional food market as equilibrium relationship between the production volume of primary food stuffs and solvent demand of the population for those. To provide the balance of demand and supply in the long-term period forecasting of production for primary food stuffs and solvent demand expected are to be implemented. Equilibration suggests establishing the balance by importing the lacking volume of the stuffs concerned to meet the solvent demand already existing as well as by exporting excessive stuffs, the demand for is less that the production volume, beyond the regional territory. When realizing the author’s approach, regression models are used which reliability levels are high.Предложен авторский подход к прогнозированию среднедушевого производства и платежеспособного спроса на основные продовольственные товары, обеспечивающий сбалансированность регионального продовольственного рынка, подобраны адекватные модели прогнозирования спроса, определен баланс спроса и  предложения этих товаров в  Новосибирской области на период 2013–2015 гг. Под сбалансированностью регионального продовольственного рынка в данной работе понимается равновесное соотношение между объемом производства основных продовольственных товаров и платежеспособным спросом населения на них. Чтобы обеспечить сбалансированность предложения и спроса на товары в перспективном периоде, следует осуществить прогноз производства основных продовольственных товаров и  ожидаемого платежеспособного спроса. Сбалансированность предполагает установление равновесия путем ввоза недостающего объема рассматриваемых товаров для удовлетворения уже сформированного платежеспособного спроса, а также вывоза за территорию региона излишков товаров, объем производства которых превышает спрос. При реализации авторского подхода применяются регрессионные модели, обладающие высокими уровнями надежности

Wladimir S. Woytinsky and Public Works in Saint Petersburg in 1906–1908: To the Problem of Studying the National Experience of Fight Unemployment

The article is devoted to as relevant as ever today the problem of unemployment and explores a little-known national experience of solving problems of employment in St. Petersburg in the early XX century associated with activity of the famous social Democrat and economist W. S. Woytinsky. The reaction of the government and society to the problem of unemployment is studied. There are noted the first experience of registering the unemployed in the history of Russia, and there are shown the unique nature of the first Public Works for the unemployed in Russia and the  largest in Europe at that time, organized jointly by the workers ' organization — the St. Petersburg Council of the Unemployed — and the St. Petersburg City Duma. There are noted negative impact of unemployment on the general situation in the capital during the First Russian revolution, as well as on the condition of the personality of factory worker. The research perspective of the problems raised in the article is outlined

Correlation between gender dimorphism of bran, cognitive functions and level of steroid hormones in period of climacteric

Authors studied the cognitive functions and the expression of bran atrophy in 101 patients with different levels of sex hormones in climacteric. Two groups were formed. The first group was of men and women with low level of sex hormones and the second group men and women with normal levels of sex hormones. Was fixed the gender-associated differences in cognitive performance and the changes the brain, more pronounced in men and women of the first group and in men than in women.Проведено исследование показателей когнитивных функций и степени атрофии головного мозга у 101 пациента с различным уровнем содержания половых гормонов в климактерическом периоде. Выделены I группа мужчин и женщин с низким содержанием половых стероидов и II группа мужчин и женщин с нормальным количеством половых гормонов. Выявлены половые различия в показателях когнитивных функций и изменение структуры головного мозга, более выраженные у мужчин и женщин I группы с преобладанием у мужчин

Atmospheric drivers of storage water use in Scots pine

International audienceIn this study we determined the microclimatic drivers of storage water use in Scots pine (Pinus sylvestris L.) growing in a temperate climate. The storage water use was modeled using the ANAFORE model, integrating a dynamic water flow and ? storage model with a process-based transpiration model. The model was calibrated and validated with sap flow measurements for the growing season of 2000 (26 May?18 October). Because there was no severe soil drought during the study period, we were able to study atmospheric effects. Incoming radiation was the main driver of storage water use. The general trends of sap flow and storage water use are similar, and follow more or less the pattern of incoming radiation. Nevertheless, considerable differences in the day-to-day pattern of sap flow and storage water use were observed, mainly driven by vapour pressure deficit (VPD). During dry atmospheric conditions (high VPD) storage water use was reduced. This reduction was disproportionally higher than the reduction in measured sap flow. Our results suggest that the trees did not rely more on storage water during periods of atmospheric drought, without severe soil drought. A third important factor was the tree water deficit. When storage compartments were depleted beyond a threshold, storage water use was limited due to the low water potential in the storage compartments. The maximum relative contribution of storage water to daily transpiration was also constrained by an increasing tree water deficit