Histological and ultrastructural studies of the marsupial Didelphis albiventris Peyer's patches

Differing from the studied Eutheria the white belly opossum Peyer"s patches do not present a conspicous dome. M cells are located in the inmer layer of bilaminal invaginations formed at the bottom of the villi. A great variation in the morphology of M cells was observed. The enterocytes located at the epithelial inner layer may present endocytic vesicles, and the microvilli are shorter tha the microvilli of enterocytes lining the small intestine. As these morphological aspects have been described to exist in the enterocytes of the lancet opossum small intstine it was surmised that the opossum Peyer's patches special epithelium could represent the persistence in adult animals of a cellular pattern established before the intestinal maturation had occurred.

Improved temporal resolution for functional studies with reduced number of segments with three-dimensional echo planar imaging.

PURPOSE: To introduce a new k-space traversal strategy for segmented three-dimensional echo planar imaging (3D EPI) that encodes two partitions per radiofrequency excitation, effectively reducing the number excitations used to acquire a 3D EPI dataset by half. METHODS: The strategy was evaluated in the context of functional MRI applications for: image quality compared with segmented 3D EPI, temporal signal-to-noise ratio (tSNR) (the ability to detect resting state networks compared with multislice two-dimensional (2D) EPI and segmented 3D EPI, and temporal resolution (the ability to separate cardiac- and respiration-related fluctuations from the desired blood oxygen level-dependent signal of interest). RESULTS: Whole brain images with a nominal voxel size of 2 mm isotropic could be acquired with a temporal resolution under half a second using traditional parallel imaging acceleration up to 4× in the partition-encode direction and using novel data acquisition speed-up of 2× with a 32-channel coil. With 8× data acquisition speed-up in the partition-encode direction, 3D reduced excitations (RE)-EPI produced acceptable image quality without introduction of noticeable additional artifacts. Due to increased tSNR and better characterization of physiological fluctuations, the new strategy allowed detection of more resting state networks compared with multislice 2D-EPI and segmented 3D EPI. CONCLUSION: 3D RE-EPI resulted in significant increases in temporal resolution for whole brain acquisitions and in improved physiological noise characterization compared with 2D-EPI and segmented 3D EPI. Magn Reson Med 72:786-792, 2014. © 2013 Wiley Periodicals, Inc.

Taxonomic studies of the subgenus Helcocyrtomya: I. Series Oswaldoi (Diptera, Psychodidae, Phlebotominae)

Attempting to review the species of sandflies in the series oswaldoi of the subgenus Helcocyrtomyia, we examined 7650 specimens collected in different Brazilian regions during 35 years and deposited in the collection of the Centro de Pesquisas René Rachou, FIOCRUZ, Belo Horizonte, MG. As main results of this study new species of Helcocyrtomyia were described (Lutzomya pusilla and Lutzomya capixaba), in addition to the females of Lutzomyia ferreirana and Lutzomyia peresi; which had been described only by the males. The geographic distribution of the material examined is also presented.

Still in the Era of Area Studies? Political-Scientific Perspectives on European Competition Policy in the 2000s

This note reviews the political-scientific literature on European competition policy (ECP) in the 2000s. Based on a data set extracted from four well-known journals, and using an upfront methodology and explicit criteria, it analyzes the literature both quantitatively and qualitatively. On the quantitative side, it shows that, although a few sub-policy areas are still neglected, ECP is not the under-researched policy it used to be. On the qualitative side, the literature has greatly improved since the 1990s: Almost all articles now present a clear research question, and most advance specific theoretical claims/hypotheses. Yet, improvements can be made on research design, statistical testing, and, above all, state-of-the-art theorizing (e.g. in the game-theoretical treatment of delegation problems). Indeed, it is paradoxical that ECP specialists do not pay more attention to theoretical questions which are so central to the actual policy area they study.

Studies on bioactive components from Chinese medicinal plants

Several novel bioactive components isolated from Chinese medicinal plants will be presented. These include novel maytansinoid tumor, inhibitors, some new ent-kaurane and rosane diterpenoids from Mallotus anomalus Meer et Chun (Euphorbiaceae), as well asnovel insecticide, stemona alkaloids from Stemona parviflora C. H. Wright (Stemonaceae). Both are native plants of Hainan island, Chine. 2D NMR techniques such as mono and hetero-COSY, NOESY, COLOC as well as H-NMR line broadening effect were utilized for structure elucidation. The separation techniques, struture elucidations and bioassay results will be reported.

Advances in pharmacological studies of silymarin

Silymarin is the flavonoids extracted from the seeds of Silybum marianum (L) Gearth as a mixture of three structural isomers: silybin, silydianin and silychristin, the former being the most active component. Silymarin protects liver cell membrane against hepatotoxic agents and improves liver function in experimental animals and humans. It is generally accepted that silymarin exerts a membrane-stabilizing action preventing or inhibiting membrane peroxidation. The experiments with soybean lipoxygenase showed that the three components of silymarin brought about a concentration-dependent non-competitive inhibition of the lipoxygenase. The experiments also showed an analogous interaction with animal lipoxygenase, thus showing that an inhibition of the peroxidation of the fatty acid in vivo was self-evident. Silybin almost completely suppressed the formation of PG at the highest concentration (0.3 mM) and proved to be an inhibitor of PG synthesis in vitro. In our experiments, silybin at lower dose (65 mg/Kg) decreased liver lipoperoxide content and microsomal lipoperoxidation to 84.5% and 68.55% of those of the scalded control rats respectively, and prevented the decrease of liver microsomal cytochrome p-450 content and p-nitroanisole-0-demethylase activity 24 h post-scalding. Effects of silymarin on cardiovascular systen have been studied in this university since 1980. O. O silymarin 800 mg/Kg/d or silybin 600 mg/Kg/d reduced plasma total cholesterol, LDL-C and VLDL-C. They however, enhanced HDL-C in hyperlipenic rats. Further studies showed that silymarin enhanced HDL-C in hyperlipemic rats. Further studies showed that silymarin enhanced HDL-C but didn't affect HDL-C, a property of this component which is beneficial to treatment of atherosclerosis. The results showed silymarin 80 mg or silybin 60 mg decreased in vitro platelet aggregation (porcentagem) in rats. The maximal platelet aggregation induced by ADP declined significantly, and time to reach maximal platelet aggregation and five-minute disaggregation didn't change. In our experiments, iv silybin 22,4 mg/kg lowered the amplitude and duration of diastolic blood pressure (DBP) more than those of systolic (SBP), but the descending aortic blood flow, cardiac contractility and ECG did not change significantly in anesthetized open-chest cats. The results indicated a reduction of peripheral resistance and dilatatory action on the resistant blood vessels. These effects are beneficial to coronary heart disease. We also observed the effects of silybin on morphological change, the release of glutamic oxaloacetate aminotrasferase (GOT) and lactate dehydrogenase (LDH) as well as the radioactivity of 3H-TdR incorporated into DNA in normal cardiac cells and cells infected by coxsackie B5, virus os newborn rats. The results showed that silynin did not affect the morphology of normal cell, and that the pathological change of cells infected by virus was delayed and reduced as compared to control. We have investigated the effect of silybin on synthesis and release of LTs in the cultured porcine cerebral basilar arteries (PCBA). Silybin 100 and 500 µmol/L declined the amounts of LTs released from the PCBA incubsated in the presence of A 23187, AA and indomenthacin. The result suggests that silybin can inhibit the activity of 5-lipoxygenase of cerebral blood vessel and may protect the brain from ischemia.

Subclinical hypothyroidism and the risk of coronary heart disease and mortality: an individual participant data analysis from nine prospective cohort studies

Texte intégral: http://www.springerlink.com/content/3q68180337551r47/fulltext.pdf

Toward a comprehensive conceptualization of business organizations and their members from a sensemaking perspective. Lessons learned from Picassoâeuro?s cubism

Until recently, much of the discussion regarding the type of organization theory needed in management studies focused on normative vs. descriptive roles of management science. Some authors however noticed that even a descriptive theory can have a normative impact. Among others, management theories are used by practitioners to make sense of their identity and roles in given contexts, and so guide their attitude, decision process, and behavior. The sensemaking potential of a theory might in this view represent an important element for predicting the adoption of a theory by practitioners. Accordingly, theories are needed which better grasp the increased complexity of today's business environment in order to be more relevant for practitioners. This article proposes a multi-faceted perspective of organizations. This implies leaving a simplistic view of organizations and building a 'cubist' conception. Picasso's cubism paintings are characterized by the use of multiple perspectives within a single drawing. Similarly, I argue here that managers must learn not only to add multiple responsibilities in their work, but to develop an integrated conception of their managerial identity and of their organizations in which the multiple social and economic dimensions are enmeshed. Social entrepreneurship is discussed as illustration of typical multi-faceted business.

A systematic review of longitudinal population-based studies on the predictors of smoking cessation in adolescent and young adult smokers

Le tabagisme est responsable de plus de 5 million de décès par an à travers le monde. En Suisse (2010), la prévalence de fumeurs chez les 14-19 ans était de 22% et la prévalence d'ex-fumeurs de 3%, taux qui reste relativement stable au fil des dernières années. La plupart des jeunes fumeurs désirant arrêter de fumer rencontrent des difficultés pour y parvenir. Les revues empiriques ont conclu que les programmes ayant pour but l'arrêt du tabagisme chez les jeunes ont une efficacité limitée. Afin de fournir une base solide de connaissances pour les programmes d'interventions contre le tabagisme, les déterminants de l'auto-cessation ont besoin d'être compris. Nous avons systématiquement recherché dans PUBMED et EMBASE des études longitudinales, basées sur la population, portant sur les déterminants de l'auto-cessation chez des adolescents et des jeunes adultes fumeurs. Nous avons passé en revue 4'502 titres et 871 abstracts, tous examinés indépendamment par deux et trois examinateurs, respectivement. Les critères d'inclusion étant : articles publiés entre janvier 1984 et août 2010, concernant les jeunes entre 10 et 29 ans et avoir une définition de cessation de fumer d'au moins 6 mois. Neuf articles ont été retenus pour une analyse détaillée. Les données suivantes ont été extraites de chaque article : le lieu de l'étude, la période étudiée, la durée du suivi, le nombre de collecte de données, la taille de l'échantillon, l'âge ou l'année scolaire des participants, le nombre de participants qui arrêtent de fumer, le status tabagique lors de la première collecte, la définition de cessation, les co-variantes et la méthode analytique. Le nombre d'études qui montrent une association significativement significative entre un déterminant et l'arrêt du tabagisme a été tabulé à partir de toutes les études qui ont évalués ce déterminant. Trois des neufs articles retenus ont défini l'arrêt du tabagisme comme une abstinence de plus de 6 mois et les six autres comme 12 mois d'abstinence. Malgré l'hétérogénéité des méthodes utilisées, cinq facteurs principaux ressortent comme prédicteur de l'arrêt du tabagisme : 1) ne pas avoir d'amis qui fument, 2) ne pas avoir l'intention de continuer de fumer dans le futur, 3) résister à la pression sociale, 4) être âgé de plus de 18 ans lors de la première cigarette, et 5) avoir un avis négatif au sujet du tabagisme. D'autres facteurs sont significatifs mais ne sont évalués que dans peu d'articles. La littérature au sujet des prédicteurs de cessation chez les adolescents et les jeunes adultes est peu développée. Cependant, nous remarquons que les facteurs que nous avons mis en évidence ne dépendent pas que de l'individu, mais aussi de l'environnement. La prévention du tabagisme peut se centrer sur les bienfaits de l'arrêt (p.ex., par rapport à l'asthme ou les performances sportives) et ainsi motiver les jeunes gens à songer d'arrêter de fumer. Une taxation plus lourde sur le prix des cigarettes peut être envisagée afin de retarder l'âge de la première cigarette. Les publicités anti-tabagiques (non sponsorisées par les entreprises de tabac) peuvent influencer la perception des jeunes par rapport au tabagisme, renforçant ou créant une attitude anti-tabagique. Les prochaines campagnes anti- tabac devraient donc tenir compte de ces différents aspects.

Life history studies of heterophyid Trematodes in the neotropical region: Ascocotyle (Leighia) hadra sp.n

The life cycle of Ascocotyle (Leighia) hadra n.sp. was experimentally reproduced, starting from cercariae from naturally infected Littoridina parchappei, collected from Los Ranchos stream, near Mercedes city, Buenos Aires Province, Argentina. Metacercariae were found encysted in the liver and mesentery of experimentally and naturally infected fishes Cnesterodon decemmaculatus and Jenynsia lineata. Adults were obtained experimentally in chicks and mice. The natural host is unknown. The new species is compared with Ascocotyle (Leighia) mcintoshi Price 1936 as described by Leigh, 1974, differing in behavior and morphology of cercarial, metacercarial and adult stages

Narrating urban entrepreneurship: a matter of imagineering?

The battle between cities with regard to their creative possibilities has evolved into a process of multiplying ever-new images and variegated stories of urban attractiveness and success. Engineering “cool” images and “hot” stories about one’s city is now a central endeavor in the narratives of urban policy-making that center more and more on the idea of the entrepreneurial city. The making of an entrepreneurial image is enacted through various narrative genres that lie somewhere between place making and place marketing, between branding and boosting, between restoration and revanchism, between iconic architecture and mega-spectacle. This “imagineering” is not only part of the way cities try to (re)present themselves as entrepreneurial to various audiences through a real “image inflation” (Zukin, 2008, p. xii) but is 1 Forthcoming in: B. Lange,.A. Kalandides, B. Stoeber, I. Wellmann (Hrsg.) (2009): Governance der Kreativwirtschaft. Diagnosen und Handlungsoptionen. Transcript-Verlag, Bielefeld. 2 also inscribed in the various ways urban creativity and entrepreneurship can be studied, researched and imagined. In this chapter we aim to differentiate the political narratives of the entrepreneurial city as we emphasize the need to understand the politics of narration and make a plea for critical reflexivity in our forms of researching and theorizing. We will thus try to investigate how the politics of narration is intertwined with the narration of political concepts and will argue that the narrating of urban entrepreneurship can raise very different images and discourses of city life beyond those that are currently engineered. We will distinguish between a grand narrative, a counter-narrative, and an assemblage of more ambivalent little narratives, which we call prosaic narration. While the distinction between these three types might be seen as a bit too simple and “straight”, we believe that by juxtaposing these different forms of narration and alternating between them, we can help problematize the engineering of the city as entrepreneurial and imagine alternative views both of city life and of what is understood as its creativity.

Public policy for entrepreneurship and innovation: impact in managed and entrepreneurial economies

Many of the most advanced economies of the world have undergone significant transformation in the last few decades. Globalization and technological changes, especially developments in information technologies, have helped to stimulate this transformation. These have contributed to changing institutional frameworks in many respects within the economies including adjustments to economic policies. The results of these transformations take many different forms and are manifested in different areas of an economy. At the heart of these changes however, has been the increasingly important role of entrepreneurship in the economy. The transformed ("new") economy stimulates and supports activities in innovation and entrepreneurship and is labelled the entrepreneurial economy. The "old" economy on the other hand restricts such activities and is referred to as the managed economy (Audretsch & Thurik, 2001).

Cross-sectional and evolutive studies of schistosomiasis mansoni in untreated and mass treated endemic areas in the southeast and northeast of Brazil

Cross-sectional and evolutive studies on schistosomiasis mansoni were carried out before and after mass treatment in the endemic areas of Capitao Andrade and Padre Paraíso, state of Minas Gerais, Riachuelo, state of Sergipe, Alhandra, state of Paraíba, and Aliança, Alegre and Coroatá, lowland of the state of Maranhao, Brazil, in the last eighteen years. The studies included clinical and fecal examination by the Kato-Katz quantitative technique, skin testfor Schistosoma mansoni infection, evaluation of man-water contact and other epidemiological investigations such as infection rate and dynamic of the snail population. Results showed: (1) Higher prevalence of S. mansoni infection, greater egg load elimination and higher and earlier morbidity of the chronic froms of the disease in the southeast areas of Capitao Andrade and Padre Paraíso; (2) The incidence of hepatosplenic form is higher in some family clusters, in whites and mullattos in all the endemic areas but develop earlier in the southeast; (3) The prevalence and morbidity of schistosomiasis are decreasing both in the mass treated northeast and in the untreated southeast areas; (4) The mass treatment reduces rapidily the prevalence of the infection and the morbidity of the disease but can not control it because of the frequent reinfections due to the intensity of man-water contact.