Human herpes virus and Alzheimer’s disease

Alzheimer’s disease (AD) is a chronic and progressive neurodegenerative disorder and according to the WHO it is estimated that 36 millions of people worldwide currently suffer from AD. Genetic and environmental factors interact in a complex interplay that might affect pathogenic mechanisms leading to age-related neurodegeneration. The hypothesis is that the presence of allelic polymorphisms in selected genes affecting individual brain susceptibility to infection by the herpes virus family during aging, may contribute to neuronal loss, inflammation and amyloid deposition. Herpes virus family show features relevant to AD, since they infect a large proportion of human population, develop a latent form persisting for several years, are difficult to eliminate by immune responses especially when latency has been established and are able to infect neurons. The association between AD and herpes viruses infection has been investigated. In particular the investigation focused on CMV, EBV and HHV-6 in DNA samples from peripheral blood of a large cohort of patients with clinical diagnosis of AD and age matched CTR, from a longitudinal population study, and DNA samples from brain tissue of patients with neuropathological diagnosis of definitive AD. An association between the presence of EBV and HHV-6 DNA from PBL positivity with the cognitive deterioration and progression to AD has been focused. Moreover, IgG plasma levels in CTR and AD to these viruses were tested. CMV and EBV IgG plasma levels were higher in elderly subjects that developed clinical AD at the end of the five year follow up. Our findings support the notion that persistent cycles of latency and reactivation of herpes viruses may contribute to impair systemic immune response and induce altered inflammatory process that in turn affect cognitive decline during aging.

Wählen im räumlichen Kontext : eine empirische Untersuchung zum Einfluss der sozialen Komposition des Wahlkreises auf die individuelle Wahlentscheidung bei der Bundestagswahl 2009

Die meisten Studien der empirischen Wahlforschung führen das Wählverhalten bei deutschen Bundestagswahlen gemäß den bewährten Erklärungsansätzen (Columbia School, Cleavage-Theorie, Michigan School, …) auf Faktoren der Individualebene zurück. Nur wenige analysieren darüber hinaus den Einfluss räumlicher Kontextmerkmale. Diese Beiträge gelangen zudem zu widersprüchlichen Befunden, z.B. darüber, welcher Anteil der Gesamtvarianz überhaupt durch Kontextfaktoren erklärt werden kann. Daher will die vorliegende Arbeit klären, inwiefern die soziale Komposition des räumlichen Kontexts über individuelle Merkmale der Wähler hinaus ihre individuelle Wahlentscheidung bei der Bundestagswahl 2009 beeinflusst hat. Dazu wird zunächst ein räumliches Mehrebenen-Modell des individuellen Wahlverhaltens entwickelt, das den Einfluss von Kontextmerkmalen u.a. auf soziale Interaktionsmechanismen innerhalb der Kontexteinheiten zurückführt. Zudem werden die zentralen individuellen Erklärungsfaktoren der oben genannten Theorien (Parteiidentifikation, Kandidaten-, Sachfragen-Orientierung, soziale Gruppenzugehörigkeit) in das Modell integriert. Auf Grundlage von Daten der German Longitudinal Election Study werden anschließend logistische Mehrebenen-Modelle für die alten und erstmals auch für die neuen Bundesländer und Deutschland geschätzt. Erstmals werden zudem Wahlkreise als relevante Kontexteinheiten untersucht. Es zeigt sich, dass ein kleiner Teil der Varianz der individuellen Wahlentscheidung allein auf Merkmale des Wahlkreises zurückgeführt werden kann. Es treten sowohl direkte Kontexteffekte als auch Mehrebenen-Interaktionseffekte auf, die sich jedoch in ihrer Wirkung zwischen den Regionen und auch zwischen den Parteien erheblich unterscheiden.

Untersuchung der Auswirkungen verschiedener Variationsbereiche des differenziellen Lernens und Lehrens im weiten Sinn auf ausgewählte technische Grundfertigkeiten im Hallenhockey

Die Frage wie großmotorische Bewegungen gelernt werden beschäftigt nicht nur Sportler, Trainer und Sportlehrer sondern auch Ärzte und Physiotherapeuten. Die sportwissenschaftlichen Teildisziplinen Bewegungs- und Trainingswissenschaft versuchen diese Frage sowohl im Sinne der Grundlagenforschung (Wie funktioniert Bewegungslernen?) als auch hinsichtlich der praktischen Konsequenzen (Wie lehrt man Bewegungen?) zu beantworten. Innerhalb dieser Themenfelder existieren Modelle, die Bewegungslernen als gezielte und extern unterstützte Ausbildung zentralnervöser Bewegungsprogramme verstehen und solche, die Lernen als Selbstorganisationsprozess interpretieren. Letzteren ist das Differenzielle Lernen und Lehren (Schöllhorn, 1999) zuzuordnen, das die Notwendigkeit betont, Bewegungen durch die Steigerung der Variationen während der Aneignungsphase zu lernen und zu lehren. Durch eine Vielzahl an Variationen, so die Modellannahme, findet der Lernende ohne externe Vorgaben selbstorganisiert ein individuelles situatives Optimum. Die vorliegende Arbeit untersucht, welchen Einfluss Variationen verschiedener Art und Größe auf die Lern- und Aneignungsleistung großmotorischer Bewegungen haben und in wie fern personenübergreifende Optima existieren. In zwei Experimenten wird der Einfluss von räumlichen (Bewegungsausführung, Bewegungsergebnis) und zeitlichen Variationen (zeitliche Verteilung der Trainingsreize) auf die Aneignungs- und Lernleistung großmotorischer sportlicher Bewegungen am Beispiel zweier technischer Grundfertigkeiten des Hallenhockeys untersucht. Die Ergebnisse der Experimente stützen die bisherige Befundlage zum Differenziellen Lernen und Lehren, wonach eine Zunahme an Variation in der Aneignungsphase zu größeren Aneignungs- und Lernleistungen führt. Zusätzlich wird die Annahme bestätigt, dass ein Zusammenhang von Variationsbereich und Lernrate in Form eines Optimaltrends vorliegt. Neu sind die Hinweise auf die Dynamik von motorischen Lernprozessen (Experiment 1). Hier scheinen individuelle Faktoren (z. B. die Lernbiografie) als auch die Phase im Lernprozess (Aneignung, Lernen) Einfluss zu haben auf den Umfang und die Struktur eines für die optimale Adaptation notwendigen Variationsbereichs. Darüber hinaus weisen die Befunde auf verschiedene Aneignungs- und Lerneffekte aufgrund alleiniger Variation der zeitlichen Verteilung bei ansonsten gleichen Trainingsreizen hin (Experiment 2). Für zukünftige Forschungsarbeiten zum Erlernen großmotorischer Bewegungen und für die sportliche Praxis dürfte es daher erkenntnisreich sein, die Historie der intrinsischen Dynamik der lernenden Systeme stärker zu berücksichtigen. Neben Fragestellungen für die Grundlagenforschung zum (Bewegungs-)Lernen ließen sich hieraus unmittelbar praxisrelevante Erkenntnisse darüber ableiten, wie Bewegungslernprozesse mittels verschiedener Variationsbereiche strukturiert und gesteuert werden könnten.

Complementary mass spectrometric techniques for the characterization of the organic fraction in atmospheric aerosols

Aerosol particles are strongly related to climate, air quality, visibility and human health issues. They contribute the largest uncertainty in the assessment of the Earth´s radiative budget, directly by scattering or absorbing solar radiation or indirectly by nucleating cloud droplets. The influence of aerosol particles on cloud related climatic effects essentially depends upon their number concentration, size and chemical composition. A major part of submicron aerosol consists of secondary organic aerosol (SOA) that is formed in the atmosphere by the oxidation of volatile organic compounds. SOA can comprise a highly diverse spectrum of compounds that undergo continuous chemical transformations in the atmosphere.rnThe aim of this work was to obtain insights into the complexity of ambient SOA by the application of advanced mass spectrometric techniques. Therefore, an atmospheric pressure chemical ionization ion trap mass spectrometer (APCI-IT-MS) was applied in the field, facilitating the measurement of ions of the intact molecular organic species. Furthermore, the high measurement frequency provided insights into SOA composition and chemical transformation processes on a high temporal resolution. Within different comprehensive field campaigns, online measurements of particular biogenic organic acids were achieved by combining an online aerosol concentrator with the APCI-IT-MS. A holistic picture of the ambient organic aerosol was obtained through the co-located application of other complementary MS techniques, such as aerosol mass spectrometry (AMS) or filter sampling for the analysis by liquid chromatography / ultrahigh resolution mass spectrometry (LC/UHRMS).rnIn particular, during a summertime field study at the pristine boreal forest station in Hyytiälä, Finland, the partitioning of organic acids between gas and particle phase was quantified, based on the online APCI-IT-MS and AMS measurements. It was found that low volatile compounds reside to a large extent in the gas phase. This observation can be interpreted as a consequence of large aerosol equilibration timescales, which build up due to the continuous production of low volatile compounds in the gas phase and/or a semi-solid phase state of the ambient aerosol. Furthermore, in-situ structural informations of particular compounds were achieved by using the MS/MS mode of the ion trap. The comparison to MS/MS spectra from laboratory generated SOA of specific monoterpene precursors indicated that laboratory SOA barely depicts the complexity of ambient SOA. Moreover, it was shown that the mass spectra of the laboratory SOA more closely resemble the ambient gas phase composition, indicating that the oxidation state of the ambient organic compounds in the particle phase is underestimated by the comparison to laboratory ozonolysis. These observations suggest that the micro-scale processes, such as the chemistry of aerosol aging or the gas-to-particle partitioning, need to be better understood in order to predict SOA concentrations more reliably.rnDuring a field study at the Mt. Kleiner Feldberg, Germany, a slightly different aerosol concentrator / APCI-IT-MS setup made the online analysis of new particle formation possible. During a particular nucleation event, the online mass spectra indicated that organic compounds of approximately 300 Da are main constituents of the bulk aerosol during ambient new particle formation. Co-located filter analysis by LC/UHRMS analysis supported these findings and furthermore allowed to determine the molecular formulas of the involved organic compounds. The unambiguous identification of several oxidized C 15 compounds indicated that oxidation products of sesquiterpenes can be important compounds for the initial formation and subsequent growth of atmospheric nanoparticles.rnThe LC/UHRMS analysis furthermore revealed that considerable amounts of organosulfates and nitrooxy organosulfates were detected on the filter samples. Indeed, it was found that several nitrooxy organosulfate related APCI-IT-MS mass traces were simultaneously enhanced. Concurrent particle phase ion chromatography and AMS measurements indicated a strong bias between inorganic sulfate and total sulfate concentrations, supporting the assumption that substantial amounts of sulfate was bonded to organic molecules.rnFinally, the comprehensive chemical analysis of the aerosol composition was compared to the hygroscopicity parameter kappa, which was derived from cloud condensation nuclei (CCN) measurements. Simultaneously, organic aerosol aging was observed by the evolution of a ratio between a second and a first generation biogenic oxidation product. It was found that this aging proxy positively correlates with increasing hygroscopicity. Moreover, it was observed that the bonding of sulfate to organic molecules leads to a significant reduction of kappa, compared to an internal mixture of the same mass fractions of purely inorganic sulfate and organic molecules. Concluding, it has been shown within this thesis that the application of modern mass spectrometric techniques allows for detailed insights into chemical and physico-chemical processes of atmospheric aerosols.rn

Das strukturierte Portfolio zur Dokumentation des orientierenden Praktikums für Lehramtsstudierende

Die Kompetenzorientierung der Lehrerbildung bezieht sich nicht nur auf die universitären Ausbildungsabschnitte des Lehramtsstudiums, sondern auch auf die praktischen Phasen. Daher ist es von Interesse, diese praktischen Phasen genauer zu untersuchen. Bisherige Forschungsarbeiten konzentrierten sich dabei vor allem auf die Kompetenzentwicklung (Bach, 2013; Gröschner & Schmitt, 2012; Schubarth et al., 2012) und auf die Betreuung im Schulpraktikum (Bach, 2013; Hascher, 2012; Schubarth et al., 2011). Die Untersuchung dieser Arbeit stellt die Praktikumsdokumentation in den Fokus, da diese ebenfalls zur Kompetenzförderung im Schulpraktikum beitragen kann. Dazu werden zwei Formen von Praktikumsdokumentationen gegenübergestellt. Dies sind einerseits die Praktikumsaufgaben, die als offene Reflexionsaufgaben formuliert werden und andererseits ein strukturiertes Arbeitsheft mit dem Ziel, die Beobachtungskompetenz der Studierenden anzuleiten und die Dokumentation der Beobachtungen zu strukturieren. Diese beiden Formen der Praktikumsdokumentation werden hinsichtlich der Akzeptanz, der Entwicklung der Kompetenzen, der Selbstwirksamkeitserwartung und des pädagogisch-psychologischen Wissens miteinander verglichen. Die Angaben von n = 66 Studierenden, die das Arbeitsheft im Orientierenden Praktikum nutzten, wurden in einem prä-post-follow-up-Design untersucht und zwei Referenzgruppen gegenübergestellt. Die erste Referenzgruppe (n = 64) hatte das Orientierende Schulpraktikum noch nicht absolviert. Die zweite Referenzgruppe (n = 105) hatte dieses beendet und mit den Praktikumsaufgaben gearbeitet. Mit Hilfe von Online-Fragebögen wurden Daten zu Rahmenbedingungen des Schulpraktikums, die selbsteingeschätzte Kompetenz der Studierenden, die Relevanz und Anwendungshäufigkeit der Kompetenzen (adaptierte Skala nach Gröschner, 2009), die allgemeine Selbstwirksamkeitserwartung (Jerusalem & Schwarzer, 1999), das pädagogisch-psychologische Wissen sowie die Akzeptanz erfasst. Die Ergebnisse zeigen keine Unterschiede in der Kompetenz- und Relevanzeinschätzung sowie bei der Selbstwirksamkeitserwartung und dem Wissen zwischen den Gruppen. Signifikant besser schätzten die Studierenden mit dem Arbeitsheft die Anwendungshäufigkeit der Kompetenzen und die Akzeptanz der Praktikumsdokumentation ein. Das neu entwickelte Arbeitsheft und die Praktikumsaufgaben fördern die Kompetenzentwicklung wahrscheinlich in vergleichbarem Maß. Die Studierenden akzeptieren das Arbeitsheft jedoch mehr, was eine wichtige Implementationsbedingung ist. Das Design der Studie sowie die Selbstselektion der Gruppen schränken die Aussagekraft der Studie ein. Zu betonen ist jedoch, dass im Rahmen dieser Studie erstmalig versucht wurde, eine längsschnittliche Interventionsstudie mit Praktikumsdokumentationen umzusetzen sowie die Gelingensbedingungen von Schulpraktika und Kompetenzentwicklung im Lehramtsstudium zu untersuchen.

The sensitivity of the photostationary state of NOx and its implication for the oxidation capacity in a semi-rural and boreal forest region

Für das Vermögen der Atmosphäre sich selbst zu reinigen spielen Stickstoffmonoxid (NO) und Stickstoffdioxid (NO2) eine bedeutende Rolle. Diese Spurengase bestimmen die photochemische Produktion von Ozon (O3) und beeinflussen das Vorkommen von Hydroxyl- (OH) und Nitrat-Radikalen (NO3). Wenn tagsüber ausreichend Solarstrahlung und Ozon vorherrschen, stehen NO und NO2 in einem schnellen photochemischen Gleichgewicht, dem „Photostationären Gleichgewichtszustand“ (engl.: photostationary state). Die Summe von NO und NO2 wird deshalb als NOx zusammengefasst. Vorhergehende Studien zum photostationären Gleichgewichtszustand von NOx umfassen Messungen an unterschiedlichsten Orten, angefangen bei Städten (geprägt von starken Luftverschmutzungen), bis hin zu abgeschiedenen Regionen (geprägt von geringeren Luftverschmutzungen). Während der photochemische Kreislauf von NO und NO2 unter Bedingungen erhöhter NOx-Konzentrationen grundlegend verstanden ist, gibt es in ländlicheren und entlegenen Regionen, welche geprägt sind von niedrigeren NOx-Konzetrationen, signifikante Lücken im Verständnis der zugrundeliegenden Zyklierungsprozesse. Diese Lücken könnten durch messtechnische NO2-Interferenzen bedingt sein - insbesondere bei indirekten Nachweismethoden, welche von Artefakten beeinflusst sein können. Bei sehr niedrigen NOx-Konzentrationen und wenn messtechnische NO2-Interferenzen ausgeschlossen werden können, wird häufig geschlussfolgert, dass diese Verständnislücken mit der Existenz eines „unbekannten Oxidationsmittels“ (engl.: unknown oxidant) verknüpft ist. Im Rahmen dieser Arbeit wird der photostationäre Gleichgewichtszustand von NOx analysiert, mit dem Ziel die potenzielle Existenz bislang unbekannter Prozesse zu untersuchen. Ein Gasanalysator für die direkte Messung von atmosphärischem NO¬2 mittels laserinduzierter Fluoreszenzmesstechnik (engl. LIF – laser induced fluorescence), GANDALF, wurde neu entwickelt und während der Messkampagne PARADE 2011 erstmals für Feldmessungen eingesetzt. Die Messungen im Rahmen von PARADE wurden im Sommer 2011 in einem ländlich geprägten Gebiet in Deutschland durchgeführt. Umfangreiche NO2-Messungen unter Verwendung unterschiedlicher Messtechniken (DOAS, CLD und CRD) ermöglichten einen ausführlichen und erfolgreichen Vergleich von GANDALF mit den übrigen NO2-Messtechniken. Weitere relevante Spurengase und meteorologische Parameter wurden gemessen, um den photostationären Zustand von NOx, basierend auf den NO2-Messungen mit GANDALF in dieser Umgebung zu untersuchen. Während PARADE wurden moderate NOx Mischungsverhältnisse an der Messstelle beobachtet (10^2 - 10^4 pptv). Mischungsverhältnisse biogener flüchtige Kohlenwasserstoffverbindungen (BVOC, engl.: biogenic volatile organic compounds) aus dem umgebenden Wald (hauptsächlich Nadelwald) lagen in der Größenordnung 10^2 pptv vor. Die Charakteristiken des photostationären Gleichgewichtszustandes von NOx bei niedrigen NOx-Mischungsverhältnissen (10 - 10^3 pptv) wurde für eine weitere Messstelle in einem borealen Waldgebiet während der Messkampagne HUMPPA-COPEC 2010 untersucht. HUMPPA–COPEC–2010 wurde im Sommer 2010 in der SMEARII-Station in Hyytiälä, Süd-Finnland, durchgeführt. Die charakteristischen Eigenschaften des photostationären Gleichgewichtszustandes von NOx in den beiden Waldgebieten werden in dieser Arbeit verglichen. Des Weiteren ermöglicht der umfangreiche Datensatz - dieser beinhaltet Messungen von relevanten Spurengasen für die Radikalchemie (OH, HO2), sowie der totalen OH-Reaktivität – das aktuelle Verständnis bezüglich der NOx-Photochemie unter Verwendung von einem Boxmodell, in welches die gemessenen Daten als Randbedingungen eingehen, zu überprüfen und zu verbessern. Während NOx-Konzentrationen in HUMPPA-COPEC 2010 niedriger sind, im Vergleich zu PARADE 2011 und BVOC-Konzentrationen höher, sind die Zyklierungsprozesse von NO und NO2 in beiden Fällen grundlegend verstanden. Die Analyse des photostationären Gleichgewichtszustandes von NOx für die beiden stark unterschiedlichen Messstandorte zeigt auf, dass potenziell unbekannte Prozesse in keinem der beiden Fälle vorhanden sind. Die aktuelle Darstellung der NOx-Chemie wurde für HUMPPA-COPEC 2010 unter Verwendung des chemischen Mechanismus MIM3* simuliert. Die Ergebnisse der Simulation sind konsistent mit den Berechnungen basierend auf dem photostationären Gleichgewichtszustand von NOx.

Analysis of evening and morning transitions in complex terrain: MATERHORN campaign 2013

A field study of thermal circulation over very gentle slope is described for a specific day characterised by weak synoptic conditions. The emphasis was on morning and evening transitions, but measurements cover the entire day; therefore a brief analysis is performed to represent the general thermal circulation pattern. Both transition periods are characterised by complex dynamic behaviours. During evening transition, the upslope flow has got through a stagnation condition characterised by wind velocity U<0:5 m=s. Only when the stagnating air has become negative buoyant, the flow is allowed to pour downslope like a slab. Some features of front formation has been found during the transition development, such as delay time of downslope flow start up along the slope, and the presence of positive turbulent kinetic energy at the onset of the motion. Eventually the observed evening transition has followed a mixed mechanisms, with features from different models. Therefore the Rayleigh number seems not to be a good criterion by which parametrise evening transition itself. Morning transition is characterised by destruction of nocturnal temperature inversion and the onset of upslope flow. Inversion destruction can be described in terms of CBL growth at surface and inversion decent from the top of the layer. KH has found to be a good indicator of inversion breakup, if used as parameter to study the inversion breakup in terms of temperature reversal. After the inversion breakup, buoyancy and mechanical productions supply the flow with the necessary energy to start the upslope wind. More quantitative analysis are provided by the study of stability parameters and turbulent kinetic energy budgets. Gradient Richardson number has been used in this terms, finding that a mixed SBL-CBL behaviour dominates the most of the observed layers. Tke budget has shown high turbulent behaviour during morning transition while the evening transition has developed entirely in laminar condition, apart from short intermittent turbulent events.

Impact Assessment: Organic Cotton in Jalalabad, Oblast, Kyrgyztan

The aim of the study was to examine the economic performance as well as perceived social and environmental impacts of organic cotton in Southern Kyrgyzstan on the basis of a comparative field study (44 certified organic farmers and 33 conventional farmers) carried out in 2009. It also investigated farmers’ motivation for and assessment of conversion to organic farming. Cotton yields on organic farms were found to be 10% lower whereby input costs per unit were 42% lower, which resulted in organic farmers having a 20% higher revenue from cotton. Due to lower input costs and organic and fair trade price premiums the average gross margin from organic cotton was 27%. In addition to direct economic benefits organic farmers enjoy a number of additional benefits such as easy access to credits on favourable terms, provision with uncontaminated cotton cooking oil and seed cake as animal feed, marketing support as well as extension and training, services provided by the newly established organic service provider. A big majority of organic farmers perceives an improvement of soil qualities, improved health conditions, and positively assesses their previous decision to convert to organic farming. The major disadvantage of organic farming is the high manual labour input required. In the study area, where manual farm work is mainly women’s work and male labour migration widespread, women are most affected by this negative aspect of organic farming. Altogether, the results suggest that despite the inconvenience of higher work load the advantages of organic farming outweigh the disadvantages and that conversion to organic farming can improve the livelihoods of small-scale farmers.

Potential and limitations of organic and fair trade cotton for improving livelihoods of smallholders: evidence from Central Asia

Cotton is a leading agricultural non-food commodity associated with soil degradation, water pollution and pesticide poisoning due to high levels of agrochemical inputs. Organic farming is often promoted as a means of addressing the economic, environmental and health risks of conventional cotton production, and it is slowly gaining ground in the global cotton market. Organic and fair trade cotton are widely seen as opportunities for smallholder farmers to improve their livelihoods thanks to higher returns, lower input costs and fewer risks. Despite an increasing number of studies comparing the profitability of organic and non-organic farming systems in developing and industrialized countries, little has been published on organic farming in Central Asia. The aim of this article is to describe the economic performance and perceived social and environmental impacts of organic cotton in southern Kyrgyzstan, drawing on a comparative field study conducted by the author in 2009. In addition to economic and environmental aspects, the study investigated farmers’ motivations toward and assessment of conversion to organic farming. Cotton yields on organic farms were found to be 10% lower, while input costs per unit were 42% lower; as a result, organic farmers’ cotton revenues were 20% higher. Due to lower input costs as well as organic and fair trade price premiums, the average gross margin from organic cotton was 27% higher. In addition to direct economic benefits, organic farmers enjoy other benefits, such as easy access to credit on favorable terms, provision of uncontaminated cottonseed cooking oil and cottonseed cake as animal feed, and marketing support as well as extension and training services provided by newly established organic service providers. The majority of organic farmers perceive improved soil quality, improved health conditions, and positively assess their initial decision to convert to organic farming. The major disadvantage of organic farming is the high manual labor input required. In the study area, where manual farm work is mainly women's work and male labor migration is widespread, women are most affected by this negative aspect of organic farming. Altogether, the results suggest that, despite the inconvenience of a higher workload, the advantages of organic farming outweigh its disadvantages and that conversion to organic farming improves the livelihoods of small-scale farmers.

Mastitis diagnostics: quantitative PCR for Staphylococcus aureus genotype B in bulk tank milk

A novel real-time quantitative PCR assay for detecting the pathogenic and contagious Staphylococcus aureus genotype B (GTB) in bulk tank milk was developed and evaluated. The detection of this pathogen in bulk tank milk would greatly facilitate its control, as it is responsible for great economic loss in Swiss dairy herds. The assay is based on the simultaneous detection of 3 GTB-typical target sequences, including 2 enterotoxin genes and a polymorphism within the leucotoxin E gene. A variety of mastitis-associated bacteria was used to validate the assays, resulting in an analytical specificity of 100% and high repeatability. The analytical sensitivity in milk was 40 cfu/mL. An exponential association between simulated cow prevalence and quantitative PCR result was observed. An initial field study revealed 1 GTB-positive herd among the 33 studied herds. This novel assay for bulk tank milk analysis is suitable for routine purposes and is expected to be an effective tool for minimizing Staph. aureus GTB in Swiss dairy herds.

Steroid hormone related male biased parasitism in chamois, Rupicapra rupicapra rupicapra

Parasites are linked with their host in a trophic interaction with implications for both hosts and parasites. Interaction stretches from the host's immune response to the structuring of communities and the evolution of biodiversity. As in many species sex determines life history strategy, response to parasites may be sex-specific. Males of vertebrate species tend to exhibit higher rates of parasites than females. Sex-associated hormones may influence immunocompetence and are hypothesised to lead to this bias. In a field study, we tested the prediction of male biased parasitism (MBP) in free ranging chamois (Rupicapra rupicapra rupicapra), which are infested intensely by gastrointestinal and lung helminths. We further investigated sex differences in faecal androgen (testosterone and epiandrosterone), cortisol and oestrogen metabolites using enzyme immunoassays (EIA) to evaluate the impact of these hormones on sex dependent parasite susceptibility. Non-invasive methods were used and the study was conducted throughout a year to detect seasonal patterns. Hormone levels and parasite counts varied significantly throughout the year. Male chamois had a higher output of gastrointestinal eggs and lungworm larvae when compared to females. The hypothesis of MBP originating in sex related hormone levels was confirmed for the elevated output of lungworm larvae, but not for the gastrointestinal nematodes. The faecal output of lungworm larvae was significantly correlated with androgen and cortisol metabolite levels. Our study shows that sex differences in steroid levels play an important role to explain MBP, although they alone cannot fully explain the phenomenon.

Assessment of estrogenic exposure in brown trout (Salmo trutta) in a Swiss midland river: integrated analysis of passive samplers, wild and caged fish, and vitellogenin mRNA and protein

This field study examined the vitellogenin (VTG) biomarker response under conditions of low and fluctuating activities of environmental estrogenicity. The present study was performed on immature brown trout (Salmo trutta) exposed to the small river Luetzelmurg, which is located in the prealpine Swiss midland region and receives effluents from a single sewage treatment plant (STP). To understand better factors influencing the relationship between estrogenic exposure and VTG induction, we compared VTG levels in caged (stationary) and feral (free-ranging) fish, VTG levels in fish from up- and downstream of the STP, and two different methods for quantifying VTG (enzyme-linked immunosorbent assay vs real-time reverse transcription-polymerase chain reaction), and we used passive samplers (polar organic chemical integrative sampler [POCIS]) to integrate the variable, bioaccumulative estrogenic load in the river water over time. The POCIS from the downstream site contained approximately 20-fold higher levels of bioassay-derived estrogen equivalents than the POCIS from the upstream site. In feral fish, this site difference in estrogenic exposure was reflected in VTG protein levels but not in VTG mRNA. In contrast, in caged fish, the site difference was evident only for VTG mRNA but not for VTG protein. Thus, the outcome of VTG biomarker measurements varied with the analytical detection method (protein vs mRNA) and with the exposure modus (caged vs feral). Our findings suggest that for environmental situations with low and variable estrogenic contamination, a multiple-assessment approach may be necessary for the assessment of estrogenic exposure in fish.

Cementless hemiarthroplasty in femoral neck fractures: evaluation of clinical results and measurement of migration by EBRA-FCA

Aim of the present study was to evaluate migration rates of cementless primary hemiarthroplasty in acute femoral neck fractures. In a longitudinal, prospective study 46 patients were treated by cementless hemiarthroplasty. Clinical follow up was correlated with the EBRA-FCA method. In 30% of all patients stem migration amounted to more than 2 mm; further, these patients were seen to have a high level of activity. A high degree of migration in more than 30% of all patients requires critical scepticism toward further use of the investigated cementless stem as hemiarthroplasty. According to literature, migration of more than 2 mm suggests a high probability of early aseptic loosening. In patients with a low degree of activity good results could be observed; nevertheless, in patients with a high level of activity the combination of the investigated cementless stem with a solid fracture head cannot be recommended.

[The incidence of Dicrocoelium dendriticum in Emmental]

A cross-sectional field study on the prevalence of Dicrocoelium dendriticum was performed in the Emmental. The study included 211 bovines, 170 equines, 20 ovines, 46 caprines and 23 rabbits (from 119 farms). In addition, laboratory routine diagnostic data obtained from 2.840 animals--all originating from the same area of investigation--were assessed in the same way. The infection extent concerning the different animal species were the following: bovines 46%, equines 12%, ovines 30%, caprines 48% and rabbits 9%. Univariate analyses of baseline epidemiological data identified no significant risk factors, with the exception of the type of stable used. Bovines kept in a modern free ranging stable had a significantly lower chance of infection with D. dendriticum than cattle in conventional tie stalls. The epidemiological data characterizing the area of investigation suggest the following procedure to reduce the problem of dicrocoeliosis: Pasturing animals of all ages should be regularly dewormed (e.g. every six week during pasture) using a compound effective against D. dendriticum. A treatment is especially indicated at the time after pasture in autumn or before housing the animals in winter. In spring, only animals having pastured the year before need to be treated prior to pasture in the new year. However, it is recommended to perform an economic analysis comparing costs of treatment versus putative costs of damage prior to the initiation of a strategic campaign: animal welfare aspects have to be considered. The laboratory routine diagnostic data showed infection extent similar to those of the cross-sectional study: bovines 60%, equines 24%, ovines 26%, caprines 31%, rabbits 32%. Atypical hosts such as dogs and cats exhibited low infection extent (3% and 1%, respectively), rather reflecting a gastro-intestinal passage of parasite eggs ingested by consumption of infected livers or by coprophagy of ruminant faeces.

Influence of prostaglandin E2 on parturition in cattle

A double-blinded, randomised, placebo-controlled field study of the influence of prostaglandin E2 (PGE2) on cattle at parturition was carried out. The extent of cervical opening and the intensity of labour were scored before administration of the compound and 10 minutes later; routine birth assistance was then continued by the veterinarian. Successful birth occurred more quickly in the cows treated with PGE2. The extent of cervical opening before the administration of the drug had a significant effect on the time to delivery, but the intensity of labour and a concomitant infusion of calcium did not have significant effects on this period. The less open the cervix before administration of the drug, the more the duration of parturition differed between the two groups, with the placebo group taking longer. A telephone follow-up inquiry found no significant differences between the cows postpartum; there were cases of mastitis and hypocalcaemia in both groups. The incidence of retained fetal membranes and the mortality of the calves were higher in the placebo group, but in neither case was the difference significant.