En torno al concepto de poder: definición colonial y redefinición postmoderna

Actualmente, los Estados resultantes de la descolonización han desarrollado una ideología dominante, forjada por la clase dirigente que evaloriza la organización estatal por medio de la escuela y los medios de comunicación. Los manuales de historia redactados desde 1960 ponen el acento en los grandes reinos y Estados tradicionales, por un lado porque su pasado es efectivamente mejor conocido pero también porque éstos representan de alguna manera un precedente a la fase actual de consolidación de grandes unidades estatales. En este contexto, las sociedades acéfalas encarnan el papel de niñas huérfanas. Tempranamente, el poder colonial las ha dotado de jefes superiores afin de poder incluirlas bajo un mismo organigrama de administracion territorial. A partir de la década del ‘90, es el Estado Senegalés, quien solicita las formas politicas tradicionales para construir la paz en territorio joola

Synthesis and Characterization of a New Bimetallic Catalyst, GJL-46, and Its Use in the Catalytic Hydrosilylation of Phenylacetylene.

A new bimetallic catalyst was synthesized from the metalation of 1,1'-(1,3-phenylene) bis(4-butyl-1 H-1,2,4-triazol-4-ium) iodide with silver oxide and the transmetalation of that complex with Rh(COD)2OTf. The structure of the compound, GJL-46, with molecular formula C34H46I2N6Rh2, was confirmed with mass spectra analysis, 1H NMR and 13C NMR. The catalytic activity of the produced molecule, GJL-46, with molecular formula C34H46I2N6Rh2, in the hydrosilylation of phenylacetylene is reported

Emergence of Convolvulaceae family species influenced by sowing depth in the soil and sugarcane straw cover

Em casa de vegetação, cinco experimentos foram desenvolvidos com o objetivo de avaliar a influência da profundidade de semeadura e da condição de cobertura do solo na emergência de plântulas de cinco espécies da família Convolvulaceae (Ipomoea hederifolia, I. nil, I. quamoclit, I. triloba e Merremia cissoides). Foi utilizada combinação fatorial entre quatro profundidades de semeadura (0, 20, 40 e 80 mm) e duas condições de solo (exposto ou coberto com palha de cana-de-açúcar em quantidade proporcional a 10 t ha-1), com delineamento experimental de blocos ao acaso e quatro repetições. Foi realizada contagem diária do número de plântulas emersas e, ao final dos experimentos, calculou-se o índice de velocidade de emergência. Quanto à profundidade de semeadura no solo, maior emergência foi observada para as sementes que foram dispostas na superfície, tanto na presença quanto na ausência de palha. Considerando-se I. hederifolia e I. nil, não foi observado efeito da cobertura do solo, nem mesmo interação de profundidade e cobertura, sobre a emergência das espécies. Para I. quamoclit, observaram-se efeitos isolados da cobertura do solo e da profundidade de alocação das sementes, que indicaram maior adaptação da espécie para emergir em solo sem palhada superficial. Também para as espécies I. triloba e M. cissoides, a emergência foi inferior nas parcelas com palha distribuída na superfície do solo, quando comparadas àquelas sem palha, e, ainda, a presença de palha reduziu a velocidade de emergência e estabelecimento das plântulas.Five trials were developed under greenhouse conditions aiming to evaluate the influence of sowing depth and soil cover condition on seedling emergence of five Convolvulaceae family species (Ipomoea hederifolia, I. nil, I. quamoclit, I. triloba and Merremia cissoides). A factorial scheme was used for four sowing depths (0, 20, 40 and 80 mm) and two soil conditions (exposed or covered with sugarcane straw in an amount proportional to 10 t ha-1);arranged in a randomized block design and four replicates. Emerged seedlings were counted daily and, at the end of the trials, emergence index speed was calculated. Regarding soil-sowing depth, higher emergence was observed for seeds distributed on the soil surface, both in the presence and absence of straw. Considering emergence of I. hederifolia and I. nil, no soil cover nor even depth x cover interaction effects were observed. For I. quamoclit, isolated soil cover effects and seed distribution depth were observed, indicating better adaptability of the species to emerge in soil without the presence of straw on the surface. Also for the species I. triloba and M. cissoides, emergence was lower in the plots with straw on the soil surface, compared to those without straw. In addition, straw distributed on the soil surface reduced emergence speed and seedling establishment

Weed seed dormancy as a survival mechanism: brief review

Um dos principais mecanismos de sobrevivência das plantas daninhas em ambientes constantemente perturbados é a alta produção de sementes. Essas possuem geralmente algum mecanismo de dormência, o qual contribui para a perpetuação de espécies interferentes nos cultivos agrícolas. A dormência pode ser caracterizada pela ausência temporária da germinação, mesmo quando em condições adequadas de sua ocorrência. Isso permite que inúmeras espécies vegetais sobrevivam às adversidades, sobretudo aquelas que dificultam ou impeçam o seu crescimento vegetativo e reprodutivo. As causas da dormência são provenientes de dois mecanismos básicos, sendo o primeiro relacionado a eventos internos das sementes (embrião) e o segundo, às características externas (tegumento, endosperma ou as barreiras impostas pelo fruto). Conceitualmente, a dormência pode ser distinguida em dois tipos: dormência primária (quando os mecanismos de dormência ocorrem ainda na planta-mãe) e secundária (quando os mecanismos de estabelecimento da dormência ocorrem após a dispersão das sementes). A ocorrência desses dois tipos de dormência é comum em plantas daninhas. A sua alternância ou ciclagem garante o fluxo de germinação destas espécies, o qual depende das características iniciais durante a formação das sementes (dormência primária) e, posteriormente, das condições ambientais (dormência secundária). Todavia, muitos são os mecanismos que coordenam a dormência, sendo a distinção destes ainda controversos. Nesse sentido, este estudo tem por objetivo abordar alguns dos principais conceitos e mecanismos de dormência em plantas daninhas, com intuito de contribuir e estimular as pesquisas, ainda escassas, nessa área.The high production of seeds in constantly disturbed environments is one of the main mechanisms of weeds survival. These seeds have usually some dormancy mechanism which constitutes weed species perpetuation in the crops. Seed dormancy can be characterized by temporally absence of the germination capacity, even though the seeds have satisfactorily conditions to germinate, thus allowing species survival under adversities, mainly those that make it difficult or hinder vegetative and reproductive growth. The causes of dormancy stem from two basic mechanisms: the first is related to inner seed events (embryo) and the second to outer characteristics in the seeds (tegument, endosperm or fruit barriers). Conceptually, dormancy can be classified as primary dormancy (when the mechanisms occur in plants-mother) and secondary dormancy (when the mechanisms causing dormancy occur after seed dispersion). These types of dormancy occur normally in weeds. Their alternation or cycling ensures germination flow these species, which depends on the characteristics occurring at the initial stages of seed formation (primary dormancy), and later, on the environmental conditions (secondary dormancy). However, many mechanisms coordinate dormancy, with the differences among them being still controversial. Thus, this study aimed to approach some of the main concepts and mechanisms in weed dormancy, in order to contribute and stimulate research which is still scarce in this area

Twenty years of surveillance of Invasive Meningococcal Diseases in Puglia, Italy

The study aims to investigate the change in the burden of disease and the microbiological characteristics of Invasive Meningococcal Disease (IMD) in Puglia in comparison with overall incidence from 1994 through 2014

Cysteine mutations in the ebolavirus matrix protein VP40 promote phosphatidylserine binding by increasing the flexibility of a lipid-binding loop

Ebolavirus (EBOV) is a negative-sense RNA virus that causes severe hemorrhagic fever in humans. The matrix protein VP40 facilitates viral budding by binding to lipids in the host cell plasma membrane and driving the formation of filamentous, pleomorphic virus particles. The C-terminal domain of VP40 contains two highly-conserved cysteine residues at positions 311 and 314, but their role in the viral life cycle is unknown. We therefore investigated the properties of VP40 mutants in which the conserved cysteine residues were replaced with alanine. The C311A mutation significantly increased the affinity of VP40 for membranes containing phosphatidylserine (PS), resulting in the assembly of longer virus-like particles (VLPs) compared to wild-type VP40. The C314A mutation also increased the affinity of VP40 for membranes containing PS, albeit to a lesser degree than C311A. The double mutant behaved in a similar manner to the individual mutants. Computer modeling revealed that both cysteine residues restrain a loop segment containing lysine residues that interact with the plasma membrane, but Cys311 has the dominant role. Accordingly, the C311A mutation increases the flexibility of this membrane-binding loop, changes the profile of hydrogen bonding within VP40 and therefore binds to PS with greater affinity. This is the first evidence that mutations in VP40 can increase its affinity for biological membranes and modify the length of Ebola VLPs. The Cys311 and Cys314 residues therefore play an important role in dynamic interactions at the plasma membrane by modulating the ability of VP40 to bind PS

VOC 202012/01 Variant Is Effectively Neutralized by Antibodies Produced by Patients Infected before Its Diffusion in Italy

The coronavirus disease 2019 (Covid-19) pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and presents a global health emergency that needs urgent intervention. Viruses constantly change through mutation, and new variants of a virus are expected to occur over time. In the United Kingdom (UK), a new variant called B.1.1.7 has emerged with an unusually large number of mutations. The aim of this study is to evaluate the level of protection of sera from 12 patients infected and later healed in Apulia Region (Italy) with Covid-19 between March and November 2020, when the English variant was not circulating in this territory yet, against the new VOC 202012/01 variant by seroneutralization assay. The sera of patients had already been tested before, using a virus belonging to the lineage B.1 and showed an antibody neutralizing titer ranging between 1:160 and 1:320. All the 12 sera donors confirmed the same titers of neutralizing antibodies obtained with a strain belonging to the lineage B.1.1.7 (VOC 202012/01). These data indicate that antibodies produced in subjects infected with variants of Sars-CoV-2 strain before the appearance of the English one, seem to have a neutralizing power also against this variant

Magnolia ovata St. Hil. seed conservation

A pesquisa foi regularizada com o objetivo de estudar a influência do teor de água da semente e da temperatura de armazenamento sobre a conservação das sementes de Magnolia ovata (Magnoliaceae), uma árvore nativa brasileira. Para tanto, sementes recém colhidas com 23,5% de água foram submetidas à secagem para a obtenção de sementes com os teores de água de 17,4%, 10,9% e 7,1%. Em seguida, as sementes foram acondicionadas em sacos de polietileno e armazenadas a 15ºC e a 20ºC. As sementes foram armazenadas por 180 dias e avaliadas mensalmente quanto ao teor de água, à emergência, ao índice e à velocidade de emergência da plântula e ao comprimento e à massa da matéria seca da plântula. A conservação das sementes de Magnolia ovata é favorecida pela secagem das sementes; as condições favoráveis para a conservação são sementes com 10,9% de água e 15ºC ou 20ºC de temperatura do ambiente de armazenamento.The research aimed to study the influence of the seed moisture content and storage temperature on Magnolia ovata (Magnoliaceae) seed conservation, a native Brazilian tree. Thus, recently harvested seeds with moisture content of 23.5% were dried to obtain seed lots with moisture content of 17.4 %, 10.9% and 7.1%. Then, seeds were placed in polyethylene bags and stored at 15ºC and 20ºC. Seeds were stored for 180 days, and were evaluated monthly for moisture content, seedling emergence, emergence index, speed of seedling emergence, seedling length and seedling dry mass. The physiological potential of M. ovata seeds was favored by drying seeds; seed conservation was favored by seed with 10.9% moisture content and 15ºC or 20ºC storage temperature.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq