Estudo da influência da calagem de solos ácidos no sistema radicular do milho (Zea mays L.), auxiliado por processamento de imagens.

Com o objetivo de avaliar a influencia da calagem, efetuada para correcao da acidez no solo, na distribuicao de raizes de milho (Zea mays L.), foram testados os materiais geneticos Cargill C525M (tolerante a acidez) e HS7777 ou HS701B (suscetivel), durante dois anos consecutivos. O experimento foi realizado na Fazenda Experimental da Universidade Federal do Parana, municipio de Piraquara (PR). O solo utilizado classifica-se como latossolo vermelho escuro, textura argilosa. Conduziu-se o experimento em arranjo de blocos ao acaso com quatro repeticoes, e quatro niveis de neutralizacao, sendo 0,1/3,2/3 e a quantidade total de calcario para neutralizacao do Al do solo (tratamentos T0,T1,T2 e T3,respectivamente), determinados atraves de curva de neutralizacao. O corretivo utilizado foi calcario Nova Terra (com 28% de CaO e 19% de MgO). Foram abertas trincheiras em duas epocas: estadio de 6 folhas e pendoamento, e avaliadas atraves da contagem visual de presenca e ausencia por um sistema reticulado de 2x2cm e pela analise das imagens digitalizadas dos perfis. Essas imagens foram avaliadas pelo SIARCS (Sistema Integrado para Analise de Raizes e Cobertura do Solo), desenvolvido pela EMBRAPA-CNPDIA, de duas formas: simulando o reticulado (presenca e ausencia) e integrando a area ocupada por raizes. Foram avaliados: profundidade maxima atingida pelo sistema radicular, distribuicao do total de raizes por camada e o diametro das raizes. Nos dois metodos que utilizam apenas a determinacao de presenca ou ausencia (...

Mismatch negativity generation in the human 5HT2A agonist and NMDA antagonist model of psychosis

RATIONALE: Many studies have reported deficits of mismatch negativity (MMN) in schizophrenic patients. Pharmacological challenges with hallucinogens in healthy humans are used as models for psychotic states. Previous studies reported a significant reduction of MMN after ketamine (N-methyl-D-aspartate acid [NMDA] antagonist model) but not after psilocybin (5HT2A agonist model). OBJECTIVES: The aim of the present study was to directly compare the two models of psychosis using an intraindividual crossover design. MATERIALS AND METHODS: Fifteen healthy subjects participated in a randomized, double-blind, crossover study with a low and a high dose of the 5HT2A agonist dimethyltryptamine (DMT) and the NMDA antagonist S-ketamine. During electroencephalographic recording, the subjects were performing the AX-version of a continuous performance test (AX-CPT). A source analysis of MMN was performed on the basis of a four-source model of MMN generation. RESULTS: Nine subjects completed both experimental days with the two doses of both drugs. Overall, we found blunted MMN and performance deficits in the AX-CPT after both drugs. However, the reduction in MMN activity was overall more pronounced after S-ketamine intake, and only S-ketamine had a significant impact on the frontal source of MMN. CONCLUSIONS: The NDMA antagonist model and the 5HT2A agonist model of psychosis display distinct neurocognitive profiles. These findings are in line with the view of the two classes of hallucinogens modeling different aspects of psychosis

Political & Quasi-Adjudicative Dispute Settlement Models in European Union Free Trade Agreements - Is the Quasi-Adjudicative Model a Trend or is it Just Another Model?

In this paper, interpretation and application dispute settlement provisions of European Union (EU) Free Trade Agreements (FTAs) signed between 1963 and 2006 are analysed. This will be through the two models of Dispute Settlement in International Law: the political and adjudicative. Political elements of dispute settlement mechanisms in Public International Law and General Agreement of Tariffs and Trade (GATT) served to establish those of the EU FTAs. Adjudicative and quasi-adjudicative elements of dispute settlement mechanisms of Public International Law and World Trade Organization (WTO) Law were used as parameters to set up those of the EU FTAs. These parameters also helped to define a new and unique hybrid model. The features of this model were found in Agreements with trade issues other than FTAs. It is possible, however, for future FTAs to incorporate them. The hybrid model is based on an adjudicative framework and includes both political and adjudicative elements. In conclusion, it was found that even though WTO Members incorporated adjudicative elements in the Dispute Settlement Understanding (DSU), the EU did not incorporate them bilaterally for a further five years. Furthermore, since the creation of the DSU in 1995, the EU has established more FTAs based on a political model than on a quasi-adjudicative. Consequently, the quasi-adjudicative dispute settlement model has not represented a clear trend in EU FTAs

Molecular biology of the blood-brain and the blood-cerebrospinal fluid barriers: similarities and differences

Efficient processing of information by the central nervous system (CNS) represents an important evolutionary advantage. Thus, homeostatic mechanisms have developed that provide appropriate circumstances for neuronal signaling, including a highly controlled and stable microenvironment. To provide such a milieu for neurons, extracellular fluids of the CNS are separated from the changeable environment of blood at three major interfaces: at the brain capillaries by the blood-brain barrier (BBB), which is localized at the level of the endothelial cells and separates brain interstitial fluid (ISF) from blood; at the epithelial layer of four choroid plexuses, the blood-cerebrospinal fluid (CSF) barrier (BCSFB), which separates CSF from the CP ISF, and at the arachnoid barrier. The two barriers that represent the largest interface between blood and brain extracellular fluids, the BBB and the BCSFB, prevent the free paracellular diffusion of polar molecules by complex morphological features, including tight junctions (TJs) that interconnect the endothelial and epithelial cells, respectively. The first part of this review focuses on the molecular biology of TJs and adherens junctions in the brain capillary endothelial cells and in the CP epithelial cells. However, normal function of the CNS depends on a constant supply of essential molecules, like glucose and amino acids from the blood, exchange of electrolytes between brain extracellular fluids and blood, as well as on efficient removal of metabolic waste products and excess neurotransmitters from the brain ISF. Therefore, a number of specific transport proteins are expressed in brain capillary endothelial cells and CP epithelial cells that provide transport of nutrients and ions into the CNS and removal of waste products and ions from the CSF. The second part of this review concentrates on the molecular biology of various solute carrier (SLC) transport proteins at those two barriers and underlines differences in their expression between the two barriers. Also, many blood-borne molecules and xenobiotics can diffuse into brain ISF and then into neuronal membranes due to their physicochemical properties. Entry of these compounds could be detrimental for neural transmission and signalling. Thus, BBB and BCSFB express transport proteins that actively restrict entry of lipophilic and amphipathic substances from blood and/or remove those molecules from the brain extracellular fluids. The third part of this review concentrates on the molecular biology of ATP-binding cassette (ABC)-transporters and those SLC transporters that are involved in efflux transport of xenobiotics, their expression at the BBB and BCSFB and differences in expression in the two major blood-brain interfaces. In addition, transport and diffusion of ions by the BBB and CP epithelium are involved in the formation of fluid, the ISF and CSF, respectively, so the last part of this review discusses molecular biology of ion transporters/exchangers and ion channels in the brain endothelial and CP epithelial cells

Le développement du droit international : réflexions d’un demi-siècle. Volume I

Dès le début des années 1960, les écrits du professeur Abi-Saab nous ont accompagnés pour nous faire découvrir les évolutions successives de l’ordre juridique international, en réponse aux grands mouvements et courants d’idées qui ont traversé le monde : la grande vague de libération nationale, qui a projeté sur le devant de la scène le principe du droit des peuples à disposer d’eux-mêmes et qui a permis à l’ONU de jouer un rôle grandissant dans l’élaboration et la mise en œuvre de ce droit ainsi que dans le règlement des conflits issus des luttes de libération nationale ; l’impact de l’expansion de la communauté internationale qui s’en est suivie, sur les structures et les normes du droit international ; la quête, au sein de cette communauté internationale devenue universelle, de plus de justice sociale à travers un Nouvel ordre économique international et un droit au développement. Depuis la Genève internationale, le professeur Abi-Saab a su influencer plusieurs générations de juristes, venant de divers horizons et cultures, par ses analyses originales des grands thèmes du droit international : ses structures, ses sources, ses sujets principaux ; ainsi que des domaines plus spécifiques, tels le droit humanitaire ou le droit économique international. À l’occasion du 80e anniversaire du professeur Abi-Saab en 2013, le professeur Marcelo Kohen et M. Magnus Jesko Langer ont réuni dans cet ouvrage une sélection d’articles publiés en français par Georges Abi-Saab, qui ne sont pas toujours facilement disponibles. Ils retracent la pensée d’un grand maître du droit international de ce dernier demi-siècle