190 research outputs found

    The Beta-1-Receptor Blocker Nebivolol Elicits Dilation of Cerebral Arteries by Reducing Smooth Muscle [Ca2+]i

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    RATIONALE: Nebivolol is known to have beta-1 blocker activity, but it was also suggested that it elicits relaxation of the peripheral arteries in part via release of nitric oxide (NO). However, the effect of nebivolol on the vasomotor tone of cerebral arteries is still unclear. OBJECTIVE: To assess the effects of nebivolol on the diameter of isolated rat basilar arteries (BA) in control, in the presence of inhibitors of vasomotor signaling pathways of know action and hemolysed blood. METHODS AND RESULTS: Vasomotor responses were measured by videomicroscopy and the intracellular Ca2+ by the Fura-2 AM ratiometric method. Under control conditions, nebivolol elicited a substantial dilation of the BA (from 216±22 to 394±20 μm; p CONCLUSIONS: Nebivolol seems to have an important dilator effect in cerebral arteries, which is mediated via several vasomotor mechanisms, converging on the reduction of smooth muscle Ca2+ levels. As such, nebivolol may be effective to improve cerebral circulation in various diseased conditions, such as hemorrhage

    Investigation of European air transport traffic by utility‐based decision model

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    Air transport was traditionally a strictly regulated industry, dominated by national flag carriers and state‐owned airports. The global deregulation and liberalisation of air transport resulted in numerous changes, including the evolution of price competition, emergence of low‐cost airlines, growth in load factor, airport and airspace capacity problems, etc. Later, the internal market eliminated all commercial restrictions for airlines flying within the European Union (EU). Constraints on routes, number of flights, regulated tariff policies, etc. were removed. Since the issue of the third liberalisation package, EU airlines are permitted to provide air services on any route within the EU. As a result, prices have fallen dramatically, especially on the most popular routes. The air transport sector has had the highest rate of development recently. These issues are discussed in the introduction of this paper. The main scope is to investigate air passenger transport within Europe and to present the mathematical formulation of a disaggregate airport choice model created by the authors. A complex utility function‐based model has been developed and verified by the authors. The results of the model are in scope with experience in the real world. Santrauka Pastaraisiais metais pastebimas itin intensyvus transporto sektoriaus vystymasis, pasireiškiantis mažinamomis kainomis, nauju pigiu avialiniju atsiradimu bei ivairiu komerciniu apribojimu panaikinimu. Pagrindinis šio darbo tikslas yra ištirti keleiviu pervežima oro transportu Europos Sajungos ribose ir pristatyti pasirinkto atskiro oro uosto modelio matematine formuluote. Modelis, paremtas kompleksinemis panaudojimo funkcijomis, buvo patobulintas ir patikrintas pačiu autoriu, o gauti rezultatai atitinka realia patirti. First Published Online: 10 Feb 2011 Reikšminiai žodžiai: keleiviu pervežimas oro transportu, panaudojimas, sprendimu modeliavima

    Quantification of plaque stiffness by Brillouin microscopy in experimental thin cap fibroatheroma

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    Plaques vulnerable to rupture are characterized by a thin and stiff fibrous cap overlaying a soft lipid-rich necrotic core. The ability to measure local plaque stiffness directly to quantify plaque stress and predict rupture potential would be very attractive, but no current technology does so. This study seeks to validate the use of Brillouin microscopy to measure the Brillouin frequency shift, which is related to stiffness, within vulnerable plaques. The left carotid artery of an ApoE-/- mouse was instrumented with a cuff that induced vulnerable plaque development in nine weeks. Adjacent histological sections from the instrumented and control arteries were stained for either lipids or collagen content, or imaged with confocal Brillouin microscopy. Mean Brillouin frequency shift was 15.79±0.09 GHz in the plaque compared with 16.24±0.15 (p \u3c 0.002) and 17.16±0.56 GHz (p \u3c 0.002) in the media of the diseased and control vessel sections, respectively. In addition, frequency shift exhibited a strong inverse correlation with lipid area of 20.67±0.06 (p \u3c 0.01) and strong direct correlation with collagen area of 0.71±0.15 (p \u3c 0.05). This is the first study, to the best of our knowledge, to apply Brillouin spectroscopy to quantify atherosclerotic plaque stiffness, which motivates combining this technology with intravascular imaging to improve detection of vulnerable plaques in patients

    Do food quality schemes and net price premiums go together?

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    This article addresses the issue of the profitability of Food Quality Scheme (FQS) products as compared to reference products, which are defined as analogous products without quality label. We approach this question by taking into account the level of the value chain (upstream, processing, and downstream), the sector (vegetal, animal, seafood) and the type of FQS (PGI, PDO, Organic). We collected original data for several products produced in selected European countries, as well as in Thailand and Vietnam. Comparisons depending on value chain level, sector and FQS are possible by using two comparable indicators: price premium and net price premium (including cost differential). The following principal conclusions were reached: 1) Price is higher for FQS products than for the reference products, regardless of the production level, the type of FQS or the sector; 2) Price premiums generated by FQS do not differ along the value chain, nor between sectors (vegetal, animal or seafood/fish); 3) Price premium for organic products is significantly higher than for PGI products, and this conclusion holds at upstream and processing levels, taking into account the costs directly related to production; 4) All organic products and almost all PDO and PGI products analysed benefit from a positive quality rent; 5) At upstream level and processing level, the relative weight of intermediate consumption in the cost structure is lower for organic products than for reference products.Objectius de Desenvolupament Sostenible::12 - Producció i Consum ResponsablesPostprint (published version

    Gyeptelepítés elmélete és gyakorlata az ökológiai szemléletű gazdálkodásban

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    Az utóbbi években egyre nagyobb az igény mind hazánkban, mind Európában a szántóföldi művelés alól kivett területek alternatív, fenntartható hasznosítására, melyre jó lehetőséget biztosít az ökológiai szemléletű gyepgazdálkodás. A gyepesítéssel szemben támasztott legfontosabb elvárás egy főképp füvek dominálta évelő gyep létrejötte, amely visszaszorítja a nemkívánatos gyomfajokat. Ökológiai célú gyeptelepítés esetén rendkívül fontos a megfelelő szaporítóanyagok, a megfelelő fűfajok kiválasztása és a természetkímélő technológia alkalmazása. A telepítendő fajokat a terület ökológiai jellemzőinek (talajtípus, vízgazdálkodás, hőmérséklet és csapadék viszonyok) figyelembe vételével és a későbbi hasznosítás (legeltetés, kaszálás) szempontjait szem előtt tartva kell kiválasztani. A telepítés időpontját és technológiáját szintén össze kell hangolni a termőhelyi adottságokkal és a későbbi hasznosítással. Legújabb kiadványunk olyan tudományos igényességgel kidolgozott, de a mindennapi gazdálkodásban alkalmazható szakanyag, amely felhívja a figyelmet az ökológiai szempontú gyeptelepítés legfontosabb szempontjaira, a gyeptelepítéshez használt magkeverékkel szemben támasztott kívánalmakra, a telepítés gyakorlati kivitelezésére, valamint várható gép- és költségigényére. A kiadvány a Debreceni Egyetem Ökológiai Tanszéke közreműködésével, Dr. Török Péter szerkesztésében valósult meg. A projekt a Magyar Nemzeti Vidéki Hálózat Elnökségének értékelése és javaslata alapján, az Európai Mezőgazdasági és Vidékfejlesztési Alap társfinanszírozásában, a Nemzeti Vidékfejlesztési Program Irányító Hatóságának jóváhagyásával válhatott valóra

    Environmental drivers and spatial scaling of species abundance distributions in Palaearctic grassland vegetation

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    [EN] Species abundance distributions (SADs) link species richness with species abundances and are an important tool in the quantitative analysis of ecological communities. Niche-based and sample-based SAD models predict different spatial scaling properties of SAD parameters. However, empirical research on SAD scaling properties is largely missing. Here we extracted percentage cover values of all occurring vascular plants as proxies of their abundance in 1725 10-m(2) plots from the GrassPlot database, covering 47 regional data sets of 19 different grasslands and other open vegetation types of the Palaearctic biogeographic realm. For each plot, we fitted the Weibull distribution, a model that is able to effectively mimic other distributions like the log-series and lognormal, to the species-log abundance rank order distribution. We calculated the skewness and kurtosis of the empirical distributions and linked these moments, along with the shape and scale parameters of the Weibull distribution, to plot climatic and soil characteristics. The Weibull distribution provided excellent fits to grassland plant communities and identified four basic types of communities characterized by different degrees of dominance. Shape and scale parameter values of local communities on poorer soils were largely in accordance with log-series distributions. Proportions of subdominant species tended to be lower than predicted by the standard lognormal SAD. Successive accumulation of plots of the same vegetation type yielded nonlinear spatial scaling of SAD moments and Weibull parameters. This scaling was largely independent of environmental correlates and geographic plot position. Our findings caution against simple generalizations about the mechanisms that generate SADs. We argue that in grasslands, lognormal-type SADs tend to prevail within a wider range of environmental conditions, including more extreme habitats such as arid environments. In contrast, log-series distributions are mainly restricted to comparatively species-rich communities on humid and fertile soils.We thank all vegetation scientists who carefully collected the plant diversity data and contributed them to GrassPlot. The Eurasian Dry Grassland Group (EDGG) and the International Association for Vegetation Science (IAVS) supported the EDGG field workshops, which generated a core part of the GrassPlot data. The Bavarian Research Alliance (via the BayIntAn scheme) and the Bayreuth Center of Ecology and Environmental Research (BayCEER) funded the initial GrassPlot workshop during which the database was established (grants to Jurgen Dengler). Werner Ulrich acknowledges support from the Polish National Science Centre (Grant 2017/27/B/NZ8/00316). Idoia Biurrun and Juan Antonio Campos were partly supported by the Basque Government (IT936-16). Goffredo Filibeck was partly supported by the MIUR initiative "Department of Excellence" (Law 232/2016) granted to DAFNE. Peter Torok was supported by the NKFIH K 119225 and K 137573 projects and the HAS Momentum Program during the manuscript preparation. Franz Essl appreciates funding by the Austrian Science Foundation FWF (Grant I 3757-B29)

    A replication study separates polymorphisms behind migraine with and without depression

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    The largest migraine genome-wide association study identified 38 candidate loci. In this study we assessed whether these results replicate on a gene level in our European cohort and whether effects are altered by lifetime depression. We tested SNPs of the loci and their vicinity with or without interaction with depression in regression models. Advanced analysis methods such as Bayesian relevance analysis and a neural network based classifier were used to confirm findings. Main effects were found for rs2455107 of PRDM16 (OR = 1.304, p = 0.007) and five intergenic polymorphisms in 1p31.1 region: two of them showed risk effect (OR = 1.277, p = 0.003 for both rs11209657 and rs6686879), while the other three variants were protective factors (OR = 0.4956, p = 0.006 for both rs12090642 and rs72948266; OR = 0.4756, p = 0.005 for rs77864828). Additionally, 26 polymorphisms within ADGRL2, 2 in REST, 1 in HPSE2 and 33 mostly intergenic SNPs from 1p31.1 showed interaction effects. Among clumped results representing these significant regions, only rs11163394 of ADGRL2 showed a protective effect (OR = 0.607, p = 0.002), all other variants were risk factors (rs1043215 of REST with the strongest effect: OR = 6.596, p = 0.003). Bayesian relevance analysis confirmed the relevance of intergenic rs6660757 and rs12128399 (p31.1), rs1043215 (REST), rs1889974 (HPSE2) and rs11163394 (ADGRL2) from depression interaction results, and the moderate relevance of rs77864828 and rs2455107 of PRDM16 from main effect analysis. Both main and interaction effect SNPs could enhance predictive power with the neural network based classifier. In summary, we replicated p31.1, PRDM16, REST, HPSE2 and ADGRL2 genes with classic genetic and advanced analysis methods. While the p31.1 region and PRDM16 are worthy of further investigations in migraine in general, REST, HPSE2 and ADGRL2 may be prime candidates behind migraine pathophysiology in patients with comorbid depression

    Drones y el orden legal internacional. Tecnología, estrategia y largas cadenas de acción

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    The main thesis of this article is that the increasing recourse to the use of unmanned aerial systems in asymmetric warfare and the beginning routinization of U.S. drone operations represent part of an evolutionary change in the spatial ordering of global politics -- Using a heuristic framework based on actor-network theory, it is argued that practices of panoptic observation and selective airstrikes, being in need of legal justification, contribute to a reterritorialization of asymmetric conflicts -- Under a new normative spatial regime, a legal condition of state immaturity is constructed, which establishes a zone of conditional sovereignty subject to transnational aerial policing -- At the same time, this process is neither a deterministic result of the new technology nor a deliberate effect of policies to which drones are merely neutral instruments -- Rather, military technology and political decisions both form part of a long chain of action which has evolved under the specific circumstances of recent military interventionsEste artículo propone que la creciente utilización de sistemas aéreos no tripulados y la rutinización de sus operaciones en guerras asimétricas representan parte de un cambio evolutivo en el ordenamiento espacial de la política global -- Utilizando un marco heurístico basado en la teoría del actor-red, se argumenta que las prácticas de observación panóptica y ataques aéreos selectivos, carentes aún de justificación legal, contribuyen a una reterritorialización de los conflictos asimétricos -- En virtud de un nuevo régimen normativo espacial, se construye una condición legal de inmadurez estatal que facilita el establecimiento de una zona de soberanía condicionada, sometida a la vigilancia aérea transnacional -- Al mismo tiempo, esté proceso no es resultado predeterminado de la nueva tecnología, ni efecto deliberado de decisiones políticas para las que los drones son solo instrumentos neutros -- Antes que ello, la tecnología militar y las decisiones políticas forman parte importante de una larga cadena de acción que se ha desarrollado en las circunstancias específicas de intervenciones militares más reciente

    The Association Between Oral Contraceptives, Depot-Medroxyprogesterone Acetate, and Trichomoniasis

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    Hormonal contraception use by women may increase the risk of acquiring certain sexually transmitted infections. We explored the effect of hormonal contraceptive use, specifically oral contraception (OC), and depot-medroxyprogesterone acetate (DMPA) on Trichomonas vaginalis infections in women
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