1,104 research outputs found

    Land Subsidence and Ground-Water Pumping: Outline

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    10 pages. Contains research sources

    Land Subsidence and Ground-Water Pumping: Outline

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    10 pages. Contains research sources

    Local differences in time and extent of mass mortality in Blackbirds ("Turdus merula" L.) after emergence of Usutu virus (USUV; Flaviviridae) in Vienna, Austria

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    Das Usutu Virus ( = USUV; Flaviviridae), vorher nur in Afrika nachgewiesen, wo es keine fatalen Auswirkungen auf Vögel oder Säugetiere hatte, verursachte erstmals im Sommer 2001 in Wien und Umgebung ein dramatisches Amselsterben. Andere Vogelarten schienen nicht vergleichbar betroffen zu sein. Als Überträger fungieren wahrscheinlich Stechmücken (Culicidae). Die Epidemie erreichte im Sommer 2003 einen Höhepunkt, anschließend entwickelte sich Immunität: Der Anteil Usutu-positiver Totfunde ging rasch zurück, zunehmend viele lebende Vögel besitzen seither Usutu-spezifische Antikörper im Blutserum. Dank unserer vor und nach dem Ereignis erhobenen Amseldichten können wir die Verluste von Teilpopulationen quantitativ belegen und nachweisen, dass es darin in Ausmaß und Zeitraum auffallend kleinräumige Unterschiede gibt. Die Zählungen wurden von den Autoren unabhängig und mit verschiedenen Methoden durchgeführt: Steiner erhob ab 1993 mittels 324 Transektzählungen (TZ) von Sept bis Juni in vier ökologisch z.T. verschiedenen Probeflächen innerhalb des Wiener Siedlungsgebietes am linken Donauufer 1993-97 und 2002-07 relative Vogeldichten (Tab.1). Holzer zählte in den Wintern 2000/01 und 2003/04 Vögel innerhalb von 41 Innenhöfen (IHZ) in zwei Flächen (eine überlappte gering mit einer von Steiner untersuchten, die zweite lag auf der anderen Donauseite), wobei eine praktisch vollständige Erfassung der Amseln möglich war (Abb.1 und 2). Die Ergebnisse bezüglich des Winterbestandes decken sich weitestgehend: Die Amseldichten waren zwischen 85 und 89% (TZ Mühlschüttel, Tab.4) bzw. 88% (IHZ, Abb.1) zurückgegangen. Für die Erhebung der Brutbestände liegen nur Zahlen aus TZ vor, als methodisch günstigster Zeitraum wurde dafür der April gewählt; Tab.5 gibt relative Abundanzen (Amseln je 1.000 m Transektlänge) an, Tab.6 Ergebnisse von Signifikanztests. In den vier Flächen war die Brutzeitdichte im gleichen Verhältnis zurückgegangen wie die im Winter (Tab.3 und 5). Aus dem für die Art am wenigsten geeigneten Teilgebiet Donaufeld liegt zwischen 2004 und 06 keine Amselfeststellung vor (Tab.1); Aussagen von zwei interessierten Familien, die am Transekt Futterstellen betreiben, erhärten diesen Befund. Erste Vögel zeigten sich dort erst wieder 2007. Auch die geringen Restbestände der übrigen drei Flächen konnten sich bis 2007 nicht erholen. Anders verlief die Entwicklung in Kaisermühlen, das nur 2,0-2,6 km von den anderen Donau-nahen Flächen entfernt liegt. Hier wurde 1998/99 und ab 2002 gezählt (35 TZ): Der Aprilbestand war 2002 um ein Drittel zurückgegangen, 2005 weniger drastisch als in den anderen Flächen eingebrochen und bereits 2006 wieder in alter Dichte vorhanden (Tab.2 und 5). Noch weniger stark wurden die Amseln der sechsten TZFläche (Wiener Innenstadt 70 TZ) betroffen, die Aprildichte war dort erst 2004 etwa auf die Hälfte reduziert und hatte sich zwei Jahre später wieder erholt (Tab.2 und 5). In beiden Fällen ging der Bestand zur Brutzeit erst zumindest ein Jahr nach Zusammenbruch des Winterbestandes zurück (Tab.3). Aus unseren Befunden lässt sich schließen, dass sich vier der untersuchten Amsel-Teilpopulationen als isolierte Standvögel verhielten, da ein winterlicher Zuzug dort praktisch nicht stattfand (in allen Monaten gleichmäßiger Rückgang) und zwischen nahe liegenden Flächen kein wesentlicher Austausch zur Auffüllung der Bestände erfolgte. Die Amseldichte dieser Flächen verblieb zumindest bis 2007 trotz der ab 2004 in Ostösterreich zunehmenden Immunität gegen USUV auf extrem niederem Niveau. Möglicherweise reduzierten überstandene USUV-Infektionen die Fitness überlebender Vögel und setzten solcherart deren Fortpflanzungerfolg herab. – Für die Bestände der restlichen beiden Gebiete hat dies offenbar geringere oder keine Bedeutung. Wenn in anderen Teilen Mitteleuropas in den Sommermonaten Totfunde von Amseln gehäuft auftreten, sollten diese mit genauer Fundortangabe versehen unverzüglich Virologen übermittelt oder bis dahin tiefgekühlt zwischengelagert werden.USUV, previously known from Africa only, never before had been associated with fatal disease in vertebrates. Beginning with summer 2001, it caused mass mortality from mid-July to September in Blackbirds of Vienna and surroundings. From 2003 to 05 herd immunity developed and the proportion of USUV-positive dead Blackbirds decreased. As we have counted urban birds before and after summer 2001, we analysed population decrease of the species quantitatively. We used different methods: Steiner counted birds from September to June in established transects in six urban areas, beginning with 1993. Holzer in two districts recorded absolute numbers of birds in courts completely enclosed by buildings, in winters 2000/01 and 2003/04 respectively. For transect-counts density in January and February was considered to be typical for winter, in April for breeding time. To an unexpected scale, we found differences between subpopulations in time and extent of mortality: In six of the eight areas, with nearest distances from 0,2 to 2,9 km to river Danube, results are identical, regardless of method. In all months and subpopulations in 2002 decrease was between 58 and 94%, in one area after 2002 the species disappeared completely for four years, as late as 2007 two birds had been found again. As decrease in all months was very similar (Tab.4) it can be concluded, that the birds are strictly resident. Four of these subpopulations investigated at breeding time also, were unable for six years to increase their very low densities – in spite of herd immunity developing in Vienna after 2003. Reduced fitness of surviving individuals could explain this phenomenon. In remaining two areas, one being situated close to river Danube and to the six cited above, decrease was recorded (1) first in winter, in April in later years only, (2) decrease was not as dramatically, (3) increase to original densities occurred within one or two years. As USUV meanwhile emerged in Hungary, northern Italy and Switzerland, in case of mass mortality in summer, it is recommended to store dead birds in frozen condition or to bring it to a veterinary institution immediately

    Appendectomy during the third trimester of pregnancy in a 27-year old patient: case report of a "near miss" complication

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    The management of acute appendicitis during pregnancy is not fully established, especially regarding the choice between open and laparoscopic surgery during the third trimester. We report herein the case of a major uterine variecele hemorrhage during a laparoscopic appendectomy in a 27-year old pregnant patient at 33 weeks of amenorrhea. After conversion to a Pfannenstiel incision, the baby was delivered, the bleeding stopped and the appendectomy completed. While both mother and child fully recovered, this «near miss» complication underlines the challenges linked to the management of acute appendicitis during pregnancy. Based on a literature review, we propose an algorithm favoring the laparoscopic approach during the first and second trimesters, and the open approach during the third trimester (especially after the 26th week of amenorrhea). In case of unclear pre-operative diagnosis, a laparoscopy should be conducted even during the third trimester with a Mc Burney conversion when the diagnosis of appendicitis is confirmed

    Tau Protein Modulates Perineuronal Extracellular Matrix Expression in the TauP301L-acan Mouse Model

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    Tau mutations promote the formation of tau oligomers and filaments, which are neuropathological signs of several tau-associated dementias. Types of neurons in the CNS are spared of tau pathology and are surrounded by a specialized form of extracellular matrix; called perineuronal nets (PNs). Aggrecan, the major PN proteoglycans, is suggested to mediate PNs neuroprotective function by forming an external shield preventing the internalization of misfolded tau. We recently demonstrated a correlation between aggrecan amount and the expression and phosphorylation of tau in a TauP310L-acan mouse model, generated by crossbreeding heterozygous aggrecan mice with a significant reduction of aggrecan and homozygous TauP301L mice. Neurodegenerative processes have been associated with changes of PN structure and protein signature. In this study, we hypothesized that the structure and protein expression of PNs in this TauP310L-acan mouse is regulated by tau. Immunohistochemical and biochemical analyses demonstrate that protein levels of PN components differ between TauP301LHET-acanWT and TauP301LHET-acanHET mice, accompanied by changes in the expression of protein phosphatase 2 A. In addition, tau can modulate PN components such as brevican. Co-immunoprecipitation experiments revealed a physical connection between PN components and tau. These data demonstrate a complex, mutual interrelation of tau and the proteoglycans of the PN

    Recovering Short Generators of Principal Fractional Ideals in Cyclotomic Fields of Conductor pαqβp^\alpha q^\beta

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    Several recent cryptographic constructions - including a public key encryption scheme, a fully homomorphic encryption scheme, and a candidate multilinear map construction - rely on the hardness of the short generator principal ideal problem (SG-PIP): given a Z\mathbb{Z}-basis of some principal (fractional) ideal in an algebraic number field that is guaranteed to have an exceptionally short generator with respect to the logarithmic embedding, find a shortest generator of the principal ideal. The folklore approach to solve this problem is to split it into two subproblems. First, recover some arbitrary generator of the ideal, which is known as the principal ideal problem (PIP). Second, solve a bounded distance decoding (BDD) problem in the log-unit lattice to transform this arbitrary generator into a shortest generator of the ideal. The first problem, i.e., solving the PIP, is known to be solvable in polynomial time on quantum computers for arbitrary number fields under the generalized Riemann hypothesis due to Biasse and Song. Cramer, Ducas, Peikert, and Regev showed, based on the work of Campbell, Groves, and Shepherd, that the second problem can be solved in polynomial time on classical computers for cyclotomic number fields of prime-power conductor. In this work, we extend the work of Cramer, Ducas, Peikert, and Regev to cyclotomic number fields K=Q(ξm)K=\mathbb{Q}(\xi_m) of conductor m=pαqβm=p^\alpha q^\beta, where p,qp,q are distinct odd primes. In more detail, we show that the second problem can be solved in classical polynomial time (with quantum polynomial time precomputation) under some sufficient conditions, if (p,q)(p,q) is an (α,β)(\alpha, \beta)-generator prime pair, a new notion introduced in this work. We further provide experimental evidence that suggests that roughly 35%35\% of all prime pairs are (α,β)(\alpha, \beta)-generator prime pairs for all α\alpha and β\beta. Combined with the work of Biasse and Song our results show that under sufficient conditions the SG-PIP can be solved in quantum polynomial time in cyclotomic number fields of composite conductor of the form pαqβp^\alpha q^\beta

    Relationship between local ski bending curvature, lean angle and radial force in alpine skiing

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    The deflection of the ski is a prerequisite for carved turns. The more the ski is edged, the more the ski has to deflect and the more radial force has to be realised in order to keep the whole edge in contact with the snow. To verify this relationship, local ski bending curvature, the lean angle and the radial force were correlated with each other. Characteristic curvature patterns as well as very large correlations (r > 0.7) between the variables were identified.Die Durchbiegung des Skis ist eine Voraussetzung für gecarvte Schwünge. Je stärker der Ski gekantet ist, desto mehr muss der Ski durchbiegen und desto mehr Radialkraft muss realisiert werden, um die gesamte Kante in Kontakt mit dem Schnee zu halten. Um diesen Zusammenhang zu verifizieren, wurden die lokale Skikrümmung, der Neigungswinkel und die Radialkraft miteinander korreliert. Es wurden sowohl charakteristische Krümmungsmuster als auch sehr große Korrelationen (r > 0,7) zwischen den Variablen festgestellt

    Renewable Electricity Tax Exemptions and Trade Remedies under International Law: An Assessment of Policy Space under WTO Law, the Swiss-EU FTA, and EU

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    A study prepared for the Swiss Federal Office of Energy (SFOE) The problem of increasing imports of subsidised renewable electricity from neighboring countries and Member States of the EU, undermining level playing fields for traditional hydropower in Switzerland, can be addressed by means of preferential taxation of electricity produced by means of renewable energy. Both under WTO law and the rules of the 1972 Free Trade Agreement, distinctions may be drawn on the basis of non-product related production and process methods, provided the same rules apply to domestic and imported electricity produced with similar methods. Differential taxation can be implemented on the basis of certificates of origin (CO) which need to be made available alike to domestic and foreign producers. A privilege exclusively granted to domestic producers cannot be lawfully sustained. Also, quantitative restrictions of imports cannot be properly justified. The study recommends adopting a system comparable to the UK model of renewable electricity exemption scheme, in place since 2001. It has not been challenged under EU law or under WTO law. To the extent that considerations of industrial policy dominate the motivation, rather than the promotion of green electricity, measures could be adopted on the basis of countervailing duties, offsetting foreign subsidies granted. Also, recourse to safeguard measures, albeit limited in time, can be contemplated. As Switzerland has little experience in taking recourse to trade remedies, a proper methodology taking into account WTO law would need to be developed and communicated in advance. Finally, efforts should be made to address the issue in negotiations with the European Union and Member States. Both unilateral measures relating to differential taxation as well as trade remedies may be used as an argument to bring about a settlement with exporting countries of subsidised electricity
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