This research has been financially supported by the Computer Science National Program of the Spanish Ministry of Economy and Competitiveness, Project Ref. #TIN2012-30768, Toho University, the University of Cantabria, and the Instituto de Fisica de Cantabria, a mixed research center of the University of Cantabria and CSIC-Consejo Superior de Investigaciones Cientificas.
The Brazilian ground pearl Eurhizococcus brasiliensis (Hemiptera: Margarodidae) is a major pest of vineyards in Brazil. In this study we evaluated the effect of imdacloprid (Premier 700 WG®), thiamethoxam (Actara 250 WG®), spirotetramat (Movento 240 SC®), fipronil (Standak®) and azadirachtin (Azamax®) to control the insect. Four experiments were conducted during two years (2009-2011) in fields naturally infested by the pest, evaluating pest control by counting the insects in the roots eight months after planting. Fipronil (Standak®, 0.37 ml of active ingredient/plant) applied in to the soil reduced pest population in 100% when compared with the control treatment (no insecticides). Soil application of fipronil was equivalent to imidacloprid and thiamethoxan standard insecticides used for Brazilian ground pearl control. Soil application of azadirachtin (Azamax®, 0.24 ml of a.i./plant) and foliar spraying of spirotetramat (Movento SC® 240, 24 ml a.i./100 L of water) reduced pest infestation in approximate 50 and 60%, respectivelly. We conclude that the soil application of fipronil provides similar control than neonicotinoid insecticides imidacloprid and thiamethoxam and azadirachtin and can be an alternative for pest suppression in organic vineyards.
O artigo tem como objetivo analisar as cartas de Lev Semenovich Vigotski, escritas no periodo de 1926 a 1934 e publicadas no Journal of Russian and East European Psychology. Esta e uma oportunidade de conhecermos um pouco mais sobre a realidade em que Vigotski viveu, e acessarmos seu itinerario intelectual, identificando os circulos de suas relacoes, suas preocupacoes academicas e suas reflexoes teoricas acerca da construcao da teoria socio historica cultural. Tal tarefa ocorreu em dois momentos, primeiramente, na traducao e sistematizacao das cartas e, posteriormente, na analise dessas, embasada no referencial teorico de estudiosos da teoria vigotskiana. Apos breve introducao do momento historico da psicologia sovietica, tracamos tres perspectivas que nos auxiliaram a analisar as cartas: (1) a situacao de sua saude e os impedimentos para realizar seu trabalho; (2) uma reflexao critica sobre a psicologia, com vistas a criar as condicoes para a emergencia de uma nova psicologia; (3) a consolidacao do grupo de trabalho, afastamentos e rupturas, em torno de questoes relativas a psicologia e seus desdobramentos teoricos e metodologicos. Enfatizamos a maneira humanista com que Vigotski vivenciou esses momentos.
The mechanism that initiates regeneration of pancreatic β-cells is not clear at present. The vagal nerve is implicated in the regulation of gastrointestinal functions, glucose metabolism and proliferation of pancreatic β-cells under physiological conditions. To elucidate the triggering mechanism of the regeneration of pancreatic β-cells, we examined the involvement of the vagal nerve. To this end, we employed a rat pancreatic duct ligation (DL) model, in which profound β-cell neogenesis and β-cell proliferation were observed within a week. We administered atropine to block the vagal nerve. Administration of atropine inhibited proliferation of β-cells in both islets and islet-like cell clusters (ICC), without affecting ductal cell proliferation in the ligated pancreas. The numbers of PDX-1 and MafB-positive cells in or attaching to the ducts were significantly reduced by atropine. MafB/glucagon and MafB/insulin double-positive cells were also decreased by atropine. Finally, atropine reduced the number of MafA-positive ductal cells, all of which were positive for insulin, by 50% on day 5. These results strongly suggest that the vagal nerve is involved in β-cell proliferation, induction of endocrine progenitors and neogenesis of α- and β-cells.
If is a projective non-degenerate variety, the X -rank of a point is defined to be the minimum integer r such that P belongs to the span of r points of X . We describe the complete stratification of the fourth secant variety of any Veronese variety X via the X -rank. This result has an equivalent translation in terms either of symmetric tensors or of homogeneous polynomials. It allows to classify all the possible integers r that can occur in the minimal decomposition of a homogeneous polynomial of X -border rank (i.e. contained in the fourth secant variety) as a linear combination of powers of linear forms.