392 research outputs found

    High-accuracy sampling of saproxylic diversity indicators at regional scales with pheromones: The case of "Elater ferrugineus" (Coleoptera, Elateridae)

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    The rare beetle Elater ferrugineus was sampled at 47 sites in the county of Östergötland, Sweden by means of pheromone-baited traps to assess its value as an indicator species for hollow oak stands rich in rare saproxylic beetle species. In addition, Osmoderma eremita was also sampled with pheromone baits. These data were then compared against species survey data collected at the same sites by pitfall and window traps. Both species co-occur with many Red Listed saproxylic beetles, with E. ferrugineus being a somewhat better indicator for the rarest species. The conservation value of a site (measured as Red List points or number of Red Listed species) increased with the number of specimens of E. ferrugineus and O. eremita caught. Accuracy of sampling by means of pheromone trapping turned out to be radically different for the two model species. E. ferrugineus traps put out during July obtained full accuracy after only 6 days, whereas O. eremita traps needed to be out from early July to mid-August in order to obtain full accuracy with one trap per site. By using E. ferrugineus, or preferably both species, as indicator species, accuracy would increase and costs decrease for saproxylic biodiversity sampling, monitoring and identification of hotspots

    Экспериментальные исследования двухфазных течений в разгонных трубках струйных мельниц

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    Розроблено й виготовлена осесиметричну модель ежектора струминного млина для дослідження двофазних течій у розгінній трубці струминного млина. Схема даної моделі за-снована на класичній схемі ежектора. Відмінність від класичної схеми складається в наяв-ності каналу підведення додаткового потоку. Канал підведення має кільцеву форму й забез-печує подачу рівномірно розподіленого захисного потоку в розгінний канал через щілинний отвір. Проведено дослідження на осесимметричной моделі ежектора, що складалися із декі-лькох етапів, перший з яких полягав у вивченні характеру плину основного потоку в розгінній трубці млина, другий – у виявленні впливу додаткового потоку газу на основний потік, тре-тій – у виявленні впливу додаткового потоку газу, направленого до розгінної трубки під ку-том 30. Аналіз досліджень показав, що додатковий потік газу виконує захисну функцію й запо-бігає впливу основного потоку на стінки розгінного каналу. Знайдені переваги додаткового потоку газу ,підведеного під кутом, меншим 90. Виявлено необхідність досліджувати оптимальний кут підведення додаткового пото-ку газу.Разработана и изготовлена осесимметричная модель эжектора струйной мельницы для исследования двухфазных течений в разгонной трубке струйной мельницы. Схема данной модели основана на классической схеме эжектора. Отличие от классической схемы состо-ит в наличии канала подвода дополнительного потока. Канал подвода имеет кольцевую форму и обеспечивает подачу равномерно распределенного защитного потока в разгонный канал через щелевое отверстие. Проведены исследования на осесимметричной модели эжектора, состоящие из не-скольких этапов, первый из которых заключался в изучении характера течения основного потока в разгонной трубке мельницы, второй – в выявлении влияния дополнительного пер-пендикулярного потока газа на основной поток, третий – в выявлении влияния дополни-тельного потока газа, направленного в разгонную трубку под углом 30. Анализ исследований показал, что дополнительный поток газа выполняет защитную функцию и предотвращает влияние основного потока на стенки разгонного канала. Обна-ружены преимущества дополнительного потока газа, подведенного под углом, меньшим 90. Выявлена необходимость исследовать оптимальный угол подвода дополнительного потока газа.Axisymmetric model of the jet mill ejector are designed and manufactured for studing two-phase flows in jet mill accelerating tube. The scheme of this model is based on the classical scheme of the ejector. Unlike the classical scheme is the inlet channel of an additional flow presence. A channel for supplying has an annular shape and provides the protective uniformly distributed flow in acceler-ating channel through the slotted inlet. The researches on the axisymmetric ejector model are examined. They consisted of several stages, the first of which was to examine the main flow pattern in the mill accelerating tube, the sec-ond was to identify the additional gas flow impact on the main flow, the third – to identify the impact of the additional gas flow directed at an angle of 30 degrees into the accelerating tube. Analyses of studies have shown that the additional gas flow has a protecting function and pre-vents the main flow effect on the accelerating channel walls. The benefits of the additional gas flow fed at an angle of less than 90 degrees are discovered. The need of investigating the optimum angle of the additional gas flow feed is identified

    Caregivers' active role in palliative home care – to encourage or to dissuade? A qualitative descriptive study

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    <p>Abstract</p> <p>Background</p> <p>Spouses' involvement in palliative care is often a prerequisite for home death, but it is unclear whether active involvement of the spouse, e.g. administering and being in charge of oral or subcutaneous medication or taking care of the patient's personal hygiene, could be harmful or have negative effects on the spouse's experience of the palliative course of disease. The aim of this study was to explore the impact of bereaved spouses' active involvement in medical and physical care on their experience of the palliative course of disease.</p> <p>Methods</p> <p>The study was a qualitative, descriptive study based on semi-structured individual interviews with seven bereaved spouses.</p> <p>Results</p> <p>Four main categories were found: Degree of involvement, Positive and Negative impact and Prerequisites. The prerequisites found for a positive outcome were Safety (24-hour back-up), Confidence (Professionals' confidence in the spouses' abilities) and Dialog (Spouses' influence on decision-making and being asked).</p> <p>Conclusion</p> <p>The results from this study identified important issues whenever spouses take an active part in medical treatment and physical care of critically ill patients in palliative care. The results question the previous research that active involvement of family care givers could be harmful and add preconditions to a positive outcome. More research into these preconditions is needed.</p

    When Is a Principal Charged With an Agent’s Knowledge?

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    Question: Detecting species presence in vegetation and making visual assessment of abundances involve a certain amount of skill, and therefore subjectivity. We evaluated the magnitude of the error in data, and its consequences for evaluating temporal trends. Location: Swedish forest vegetation. Methods: Vegetation data were collected independently by two observers in 342 permanent 100-m2 plots in mature boreal forests. Each plot was visited by one observer from a group of 36 and one of two quality assessment observers. The cover class of 29 taxa was recorded, and presence/absence for an additional 50. Results: Overall, one third of each occurrence was missed by one of the two observers, but with large differences among species. There were more missed occurrences at low abundances. Species occurring at low abundance when present tended to be frequently overlooked. Variance component analyses indicated that cover data on 5 of 17 species had a significant observer bias. Observer-explained variance was &lt; 10% in 15 of 17 species. Conclusion: The substantial number of missed occurrences suggests poor power in detecting changes based on presence/absence data. The magnitude of observer bias in cover estimates was relatively small, compared with random error, and therefore potentially analytically tractable. Data in this monitoring system could be improved by a more structured working model during field work.Original publication: Milberg, P., Bergstedt, J., Fridman, J., Odell, G & Westerberg, L., Systematic and random variation in vegetation monitoring data, 2008, Journal of Vegetation Science, (19), 633-644. http://dx.doi.org/10.3170/2008-8-18423. Copyright: Opulus Press, http://www.opuluspress.se/index.ph

    Arrhythmogenic mechanisms in the isolated perfused hypokalaemic murine heart

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    AIM: Hypokalaemia is associated with a lethal form of ventricular tachycardia (VT), torsade de pointes, through pathophysiological mechanisms requiring clarification. METHODS: Left ventricular endocardial and epicardial monophasic action potentials were compared in isolated mouse hearts paced from the right ventricular epicardium perfused with hypokalaemic (3 and 4 mm [K(+)](o)) solutions. Corresponding K(+) currents were compared in whole-cell patch-clamped epicardial and endocardial myocytes. RESULTS: Hypokalaemia prolonged epicardial action potential durations (APD) from mean APD(90)s of 37.2 ± 1.7 ms (n = 7) to 58.4 ± 4.1 ms (n =7) and 66.7 ± 2.1 ms (n = 11) at 5.2, 4 and 3 mm [K(+)](o) respectively. Endocardial APD(90)s correspondingly increased from 51.6 ± 1.9 ms (n = 7) to 62.8 ± 2.8 ms (n = 7) and 62.9 ± 5.9 ms (n = 11) giving reductions in endocardial–epicardial differences, ΔAPD(90), from 14.4 ± 2.6 to 4.4 ± 5.0 and −3.4 ± 6.0 ms respectively. Early afterdepolarizations (EADs) occurred in epicardia in three of seven spontaneously beating hearts at 4 mm [K(+)](o) with triggered beats followed by episodes of non-sustained VT in nine of 11 preparations at 3 mm. Programmed electrical stimulation never induced arrhythmic events in preparations perfused with normokalemic solutions yet induced VT in two of seven and nine of 11 preparations at 4 and 3 mm [K(+)](o) respectively. Early outward K(+) current correspondingly fell from 73.46 ± 8.45 to 61.16±6.14 pA/pF in isolated epicardial but not endocardial myocytes (n = 9) (3 mm [K(+)](o)). CONCLUSIONS: Hypokalaemic mouse hearts recapitulate the clinical arrhythmogenic phenotype, demonstrating EADs and triggered beats that might initiate VT on the one hand and reduced transmural dispersion of repolarization reflected in ΔAPD(90) suggesting arrhythmogenic substrate on the other

    Separation of early afterdepolarizations from arrhythmogenic substrate in the isolated perfused hypokalaemic murine heart through modifiers of calcium homeostasis

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    In human type 1 diabetes (T1D) and in its murine model, the major histocompatibility complex (MHC) class II molecules, human leukocyte antigens (HLA)-DQ and -DR and their murine orthologues, IA and IE, are the major genetic determinants. In this report, we have ranked HLA class II molecule-associated T1D risk in a two-sided gradient from very high to very low. Very low risk corresponded to dominant protection from T1D. We predicted the protein structure of DQ by using the published crystal structures of different allotypes of the murine orthologue of DQ, IA. We discovered marked similarities both within, and cross species between T1D protective class II molecules. Likewise, the T1D predisposing molecules showed conserved similarities that contrasted with the shared patterns observed between the protective molecules. We also found striking inter-isotypic conservation between protective DQ, IA allotypes and protective DR4 subtypes. The data provide evidence for a joint action of the class II peptide-binding pockets P1, P4 and P9 in disease susceptibility and resistance with a main role for P9 in DQ/IA and for P1 and P4 in DR/IE. Overall, these results suggest shared epitope(s) in the target autoantigen(s), and common pathways in human and murine T1D

    Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.

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    The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD

    The contribution of refractoriness to arrhythmic substrate in hypokalemic Langendorff-perfused murine hearts

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    The clinical effects of hypokalemia including action potential prolongation and arrhythmogenicity suppressible by lidocaine were reproduced in hypokalemic (3.0 mM K(+)) Langendorff-perfused murine hearts before and after exposure to lidocaine (10 μM). Novel limiting criteria for local and transmural, epicardial, and endocardial re-excitation involving action potential duration (at 90% repolarization, APD(90)), ventricular effective refractory period (VERP), and transmural conduction time (Δlatency), where appropriate, were applied to normokalemic (5.2 mM K(+)) and hypokalemic hearts. Hypokalemia increased epicardial APD(90) from 46.6 ± 1.2 to 53.1 ± 0.7 ms yet decreased epicardial VERP from 41 ± 4 to 29 ± 1 ms, left endocardial APD(90) unchanged (58.2 ± 3.7 to 56.9 ± 4.0 ms) yet decreased endocardial VERP from 48 ± 4 to 29 ± 2 ms, and left Δlatency unchanged (1.6 ± 1.4 to 1.1 ± 1.1 ms; eight normokalemic and five hypokalemic hearts). These findings precisely matched computational predictions based on previous reports of altered ion channel gating and membrane hyperpolarization. Hypokalemia thus shifted all re-excitation criteria in the positive direction. In contrast, hypokalemia spared epicardial APD(90) (54.8 ± 2.7 to 60.6 ± 2.7 ms), epicardial VERP (84 ± 5 to 81 ± 7 ms), endocardial APD(90) (56.6 ± 4.2 to 63.7 ± 6.4 ms), endocardial VERP (80 ± 2 to 84 ± 4 ms), and Δlatency (12.5 ± 6.2 to 7.6 ± 3.4 ms; five hearts in each case) in lidocaine-treated hearts. Exposure to lidocaine thus consistently shifted all re-excitation criteria in the negative direction, again precisely agreeing with the arrhythmogenic findings. In contrast, established analyses invoking transmural dispersion of repolarization failed to account for any of these findings. We thus establish novel, more general, criteria predictive of arrhythmogenicity that may be particularly useful where APD(90) might diverge sharply from VERP

    Outsourcing and structural change: shifting firm and sectoral boundaries

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    The paper aims at investigating the structural change implications of outsourcing. In trying to bridge the organizational/industrial and the sectoral/structural analysis of outsourcing, it discusses the rational and the methodological pros and cons of a “battery” of outsourcing measurements for structural change analysis. Their functioning is then illustrated through a concise application of them to the OECD area over the ’80s and the early ’90s. A combined used of them emerges as recommendable in checking for the role of outsourcing with respect to that of other structural change determinants
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