369 research outputs found

    Economics and Business handbook

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    2002 handbook for the faculty of Economics and Busines

    How visual information influences dual-task driving and tracking

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    The study examined the impact of visual predictability on dual-task performance in driving and tracking tasks. Participants (N = 27) performed a simulated driving task and a pursuit tracking task. In either task, visual predictability was manipulated by systematically varying the amount of advance visual information: in the driving task, participants drove at night with low beam, at night with high beam, or in daylight; in the tracking task, participants saw a white line that specified the future target trajectory for 200, 400 or 800 ms. Concurrently with driving or tracking, participants performed an auditory task. They had to discriminate between two sounds and press a pedal upon hearing the higher sound. Results show that in general, visual predictability benefited driving and tracking; however, dual-task driving performance was best with highest visual predictability (daylight), dual-task tracking performance was best with medium visual predictability (400 ms). Braking/reaction times were higher in dual tasks compared to single tasks, but were unaffected by visual predictability, showing that its beneficial effects did not transfer to the auditory task. In both tasks, manual accuracy decreased around the moment the foot pressed the pedal, indicating interference between tasks. We, therefore, conclude that despite a general beneficial impact of predictability, the integration of visual information seems to be rather task specific, and that interference between driving and audiomotor tasks, and tracking and audiomotor tasks, seems comparable

    Dispersal of the monarch butterfly (Danaus plexippus) over southern Spain from its breeding grounds

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    Dispersión de la mariposa monarca (Danaus plexippus) en el sur de España desde las zonas de apareamiento Durante el período comprendido entre los años 2000 y 2016, se detectaron mariposas monarca en 127 lugares fuera de las zonas costeras donde se reproducen habitualmente en el sur de la península ibérica. Estos datos se obtuvieron en verano e invierno, coincidiendo con la máxima abundancia de individuos y la mayor proporción de sitios ocupados en sus zonas de reproducción cercanas al estrecho de Gibraltar. Los individuos que se dispersan no tienen ninguna posibilidad de establecer nuevas colonias en estos sitios porque las plantas en las que ponen los huevos no crecen en las localidades en las que fueron detectados. Sin embargo, estos movimientos de dispersión podrían ser la causa de la colonización de plantas alimentarias que crecen en otras zonas de la península ibérica y en otros países del Mediterráneo.From 2000–2016, monarch butterflies were detected at 127 locations away from their usual coastal breeding areas in the south of the Iberian peninsula. These findings were recorded in the summer–autumn period, coinciding with the highest abundance of individuals and the highest proportion of patches occupied in their reproduction areas near the Strait of Gibraltar. These dispersing individuals have no chance of successfully establishing new colonies at these sites because the food plants for egg laying do not grow in the localities where they were detected. However, these dispersive movements could be the source of their successful colonisation on food plants growing in other areas of the Iberian peninsula and in other Mediterranean countries.Dispersión de la mariposa monarca (Danaus plexippus) en el sur de España desde las zonas de apareamiento Durante el período comprendido entre los años 2000 y 2016, se detectaron mariposas monarca en 127 lugares fuera de las zonas costeras donde se reproducen habitualmente en el sur de la península ibérica. Estos datos se obtuvieron en verano e invierno, coincidiendo con la máxima abundancia de individuos y la mayor proporción de sitios ocupados en sus zonas de reproducción cercanas al estrecho de Gibraltar. Los individuos que se dispersan no tienen ninguna posibilidad de establecer nuevas colonias en estos sitios porque las plantas en las que ponen los huevos no crecen en las localidades en las que fueron detectados. Sin embargo, estos movimientos de dispersión podrían ser la causa de la colonización de plantas alimentarias que crecen en otras zonas de la península ibérica y en otros países del Mediterráneo

    Gomphocarpus R. Br. (Apocynaceae sufma. Asclepiadoideae) en Andalucía Occidental

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    Se da a conocer la presencia en Andalucía Occidental de Gomphocarpus physocarpus E. Mey., un neófi to originario del E y S de África. Se comenta la fenología de la fl oración y fructifi cación, así como la capacidad de dispersión de las plantas en las poblaciones naturalizadas, y se comparan con las de G. fruticosus (L.) T.W. Aiton, también presente en el territorio. Se discute el carácter invasor de las tres especies de Asclepiadaceae citadas en el texto.In this article the neophyte Gomphocarpus physocarpus E.Mey., widely distributed in SE Africa, is fi rst cited in western Andalucía (southern Spain). The flowering and fruit ripening phenology and dispersal potential of plants in different naturalized populations are described and compared with that of G. fruticosus (L.) T.W. Aiton also present in this territory. The invasive potential of the three Asclepiadaceae species here considered is also discussed.Fundación MIGRE

    An early secretory pathway mediated by GNOM-LIKE 1 and GNOM is essential for basal polarity establishment in Arabidopsis thaliana

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    Spatial regulation of the plant hormone indole-3-acetic acid (IAA, or auxin) is essential for plant development. Auxin gradient establishment is mediated by polarly localized auxin transporters, including PIN-FORMED (PIN) proteins. Their localization and abundance at the plasma membrane are tightly regulated by endo-membrane machinery, especially the endocytic and recycling pathways mediated by the ADP ribosylation factor guanine nucleotide exchange factor (ARF-GEF) GNOM. We assessed the role of the early secretory pathway in establishing PIN1 polarity in Arabidopsis thaliana by pharmacological and genetic approaches. We identified the compound endosidin 8 (ES8), which selectively interferes with PIN1 basal polarity without altering the polarity of apical proteins. ES8 alters the auxin distribution pattern in the root and induces a strong developmental phenotype, including reduced root length. The ARF-GEF-defective mutants gnom-like 1 (gnl1-1) and gnom (van7) are significantly resistant to ES8. The compound does not affect recycling or vacuolar trafficking of PIN1 but leads to its intracellular accumulation, resulting in loss of PIN1 basal polarity at the plasma membrane. Our data confirm a role for GNOM in endoplasmic reticulum (ER)-Golgi trafficking and reveal that a GNL1/GNOM-mediated early secretory pathway selectively regulates PIN1 basal polarity establishment in a manner essential for normal plant development

    Пористая структура продуктов электрохимического синтеза на переменном токе нанодисперсных оксидов олова

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    Методами электронной микроскопии и низкотемпературной адсорбции азота изучена пористая структура продуктов электролиза металлического олова на переменном токе промышленной частоты. Установлено, что продукты синтеза характеризуются высокими значениями удельной площади поверхности и мезапористой структурой. Показано, что средний размер частиц варьирует в интервале 10…30 нм

    Fibroblast Growth Factor Signaling Mediates Pulmonary Endothelial Glycocalyx Reconstitution

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    The endothelial glycocalyx is a heparan sulfate (HS)-rich endovascular structure critical to endothelial function. Accordingly, endothelial glycocalyx degradation during sepsis contributes to tissue edema and organ injury. We determined the endogenous mechanisms governing pulmonary endothelial glycocalyx reconstitution, and if these reparative mechanisms are impaired during sepsis. We performed intravital microscopy of wild-type and transgenic mice to determine the rapidity of pulmonary endothelial glycocalyx reconstitution after nonseptic (heparinase-III mediated) or septic (cecal ligation and puncture mediated) endothelial glycocalyx degradation. We used mass spectrometry, surface plasmon resonance, and in vitro studies of human and mouse samples to determine the structure of HS fragments released during glycocalyx degradation and their impact on fibroblast growth factor receptor (FGFR) 1 signaling, a mediator of endothelial repair. Homeostatic pulmonary endothelial glycocalyx reconstitution occurred rapidly after nonseptic degradation and was associated with induction of the HS biosynthetic enzyme, exostosin (EXT)-1. In contrast, sepsis was characterized by loss of pulmonary EXT1 expression and delayed glycocalyx reconstitution. Rapid glycocalyx recovery after nonseptic degradation was dependent upon induction of FGFR1 expression and was augmented by FGF-promoting effects of circulating HS fragments released during glycocalyx degradation. Although sepsis-released HS fragments maintained this ability to activate FGFR1, sepsis was associated with the downstream absence of reparative pulmonary endothelial FGFR1 induction. Sepsis may cause vascular injury not only via glycocalyx degradation, but also by impairing FGFR1/EXT1-mediated glycocalyx reconstitution

    The effect of secondary inorganic aerosols, soot and the geographical origin of air mass on acute myocardial infarction hospitalisations in Gothenburg, Sweden during 1985 - 2010 : a case-crossover study

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    BACKGROUND: The relative importance of different sources of air pollution for cardiovascular disease is unclear. The aims were to compare the associations between acute myocardial infarction (AMI) hospitalisations in Gothenburg, Sweden and 1) the long-range transported (LRT) particle fraction, 2) the remaining particle fraction, 3) geographical air mass origin, and 4) influence of local dispersion during 1985–2010. METHODS : A case-crossover design was applied using lag0 (the exposure the same day as hospitalisation), lag1 (exposure one day prior hospitalisation) and 2-day cumulative average exposure (CA2) (mean of lag0 and lag1). The LRT fractions included PMion (sum of sulphate, nitrate and ammonium) and soot measured at a rural site. The difference between urban PM10 (particulate matter with an aerodynamic diameter smaller than 10 μm) and rural PMion was a proxy for locally generated PM10 (PMrest). The daily geographical origin of air mass was estimated as well as days with limited or effective local dispersion. The entire year was considered, as well as warm and cold periods, and different time periods. RESULTS : In total 28 215 AMI hospitalisations occurred during 26 years. PM10, PMion, PMrest and soot did not influence AMI for the entire year. In the cold period, the association was somewhat stronger for PMrest than for urban PM10; the strongest associations were observed during 1990–2000 between AMI and CA2 of PMrest (6.6% per inter-quartile range (IQR), 95% confidence interval 2.1 to 11.4%) and PM10 (4.1%, 95% CI 0.2% − 8.2%). Regarding the geographical air mass origins there were few associations. Days with limited local dispersion showed an association with AMI in the cold period of 2001–2010 (6.7%, 95% CI 0.0% − 13.0%). CONCLUSIONS : In the cold period, locally generated PM and days with limited local dispersion affected AMI hospitalisations, indicating importance of local emissions from e.g. traffic.The Swedish Research Council Formas funded the study.http://www.ehjournal.netam201

    Collective cancer invasion forms an integrin-dependent radioresistant niche

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    Contains fulltext : 219833.pdf (Publisher’s version ) (Open Access)Cancer fatalities result from metastatic dissemination and therapy resistance, both processes that depend on signals from the tumor microenvironment. To identify how invasion and resistance programs cooperate, we used intravital microscopy of orthotopic sarcoma and melanoma xenografts. We demonstrate that these tumors invade collectively and that, specifically, cells within the invasion zone acquire increased resistance to radiotherapy, rapidly normalize DNA damage, and preferentially survive. Using a candidate-based approach to identify effectors of invasion-associated resistance, we targeted beta1 and alphaVbeta3/beta5 integrins, essential extracellular matrix receptors in mesenchymal tumors, which mediate cancer progression and resistance. Combining radiotherapy with beta1 or alphaV integrin monotargeting in invading tumors led to relapse and metastasis in 40-60% of the cohort, in line with recently failed clinical trials individually targeting integrins. However, when combined, anti-beta1/alphaV integrin dual targeting achieved relapse-free radiosensitization and prevented metastatic escape. Collectively, invading cancer cells thus withstand radiotherapy and DNA damage by beta1/alphaVbeta3/beta5 integrin cross-talk, but efficient radiosensitization can be achieved by multiple integrin targeting

    Potential release of aluminum and other metals by food-grade aluminum foil used for skin allograft cryo preservation

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    Since 1991, the skin bank of the Queen Astrid Military Hospital uses food-grade aluminum foil as a primary support for storing cryo preserved human donor skin (511 donors). The possible release of heavy metals into the cryo preservation media (30% (v/v) glycerol in physiological water) and the possible impact this release could have on the quality of the cryo preserved donor skin was evaluated. Aluminum was the principal detection target. Possible contaminants of the aluminum foil as such (arsenic, cadmium, chromium and lead) were also investigated. The evaluation was set up after a Belgian Competent Authority inspection remark. Aluminum was detected at a concentration of 1.4 mg/l, arsenic and lead were not detected, while cadmium and chromium were detected in trace element quantities. An histological analysis revealed no differences between cryo preserved and fresh donor skin. No adverse reactions in patients, related to the presence of aluminum or heavy metal traces, were reported since the introduction of the cryo preserved donor skin in our burn wound centre
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