37 research outputs found

    Kundenbindung durch Gratis-Musikdownloads: Eine empirische Untersuchung am Beispiel des Klassikmarktes in der Schweiz

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    Das Internet hat einen Wandel in der Musikindustrie bewirkt. Insbesondere CD-VerkĂ€ufe werden durch die zunehmende Verbreitung von Gratis-Musikdownloads (GMD) konkurrenziert. Im Zuge der Anpassung an diese neue Situation sind Musikanbieter gezwungen, neue Marketingmaßnahmen zur Bewerbung ihrer Musik zu ergreifen. Dabei bergen GMD nicht nur Gefahren sondern auch ein gewisses Potenzial als Marketinginstrument. Die vorliegende Studie untersucht am Beispiel des Klassikmarktes, wie GMD als Kundenbindungs-instrument eingesetzt werden können. Mit Hilfe der Kundenbindungstheorie wurde ein konzeptuelles Modell zu Voraussetzungen und Wirkungen von GMD in der Klassik entwickelt, das anhand einer experimentellen Umfrage mit 2x2-faktoriellem Design getestet wurde. Die Ergebnisse zeigen, dass die TonqualitĂ€t sowie die LĂ€nge des StĂŒckausschnitts von GMD das wahrgenommene Wissen wie auch die Einstellung zur Musik eines Orchesters positiv beeinflussen. DarĂŒber hinaus können GMD auch Verhaltensabsichten bezĂŒglich des Kaufs von TontrĂ€gern, des Besuchs eines Konzerts oder der Weiter-empfehlung von Musik bewirken. Die Ergebnisse zeigen, dass sich GMD in Form eines Samplings als Instrument zur Kundenbindung verwenden lassen

    Infestation of Transgenic Powdery Mildew-Resistant Wheat by Naturally Occurring Insect Herbivores under Different Environmental Conditions

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    A concern associated with the growing of genetically modified (GM) crops is that they could adversely affect non-target organisms. We assessed the impact of several transgenic powdery mildew-resistant spring wheat lines on insect herbivores. The GM lines carried either the Pm3b gene from hexaploid wheat, which confers race-specific resistance to powdery mildew, or the less specific anti-fungal barley seed chitinase and ÎČ-1,3-glucanase. In addition to the non-transformed control lines, several conventional spring wheat varieties and barley and triticale were included for comparison. During two consecutive growing seasons, powdery mildew infection and the abundance of and damage by naturally occurring herbivores were estimated under semi-field conditions in a convertible glasshouse and in the field. Mildew was reduced on the Pm3b-transgenic lines but not on the chitinase/glucanase-expressing lines. Abundance of aphids was negatively correlated with powdery mildew in the convertible glasshouse, with Pm3b wheat plants hosting significantly more aphids than their mildew-susceptible controls. In contrast, aphid densities did not differ between GM plants and their non-transformed controls in the field, probably because of low mildew and aphid pressure at this location. Likewise, the GM wheat lines did not affect the abundance of or damage by the herbivores Oulema melanopus (L.) and Chlorops pumilionis Bjerk. Although a previous study has revealed that some of the GM wheat lines show pleiotropic effects under field conditions, their effect on herbivorous insects appears to be low

    Lysates of Methylococcus capsulatus Bath induce a lean-like microbiota, intestinal FoxP3+RORÎłt+IL-17+ Tregs and improve metabolism

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    Interactions between host and gut microbial communities are modulated by diets and play pivotal roles in immunological homeostasis and health. We show that exchanging the protein source in a high fat, high sugar, westernized diet from casein to whole-cell lysates of the non-commensal bacterium Methylococcus capsulatus Bath is sufficient to reverse western diet-induced changes in the gut microbiota to a state resembling that of lean, low fat diet-fed mice, both under mild thermal stress (T22 °C) and at thermoneutrality (T30 °C). Concomitant with microbiota changes, mice fed the Methylococcus-based western diet exhibit improved glucose regulation, reduced body and liver fat, and diminished hepatic immune infiltration. Intake of the Methylococcu-based diet markedly boosts Parabacteroides abundances in a manner depending on adaptive immunity, and upregulates triple positive (Foxp3+RORγt+IL-17+) regulatory T cells in the small and large intestine. Collectively, these data point to the potential for leveraging the use of McB lysates to improve immunometabolic homeostasis.publishedVersio

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Transgenic wheat and non-target impacts on insect herbivores and food webs

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    This PhD work was conducted within the Wheat Cluster which is a subunit of the National Research Programme NRP 59 “Benefits and risks of the deliberate release of genetically modified plants”. The Wheat Cluster conducted field experiments with selected genetically modified (GM) spring wheat lines with enhanced resistance to powdery mildew. In this project we investigated the effects of the GM wheat plants on insect herbivores amongst which we worked with aphids and their associated food webs. We hypothesized that alterations in the metabolism of GM wheat plants could affect feeding behaviour, growth and fitness of insect herbivores and their natural enemies. We investigated our hypothesis in the field, in a semi-field environment (convertible glasshouse), and under confined conditions (glasshouse, climate chambers). The experiments in the field and the convertible glasshouse focussed on naturally occurring herbivore populations and on aphid-parasitoid food webs. Complementary experiments in the glasshouse and climate chambers were performed to better understand the mechanisms driving the plant-insect interactions. In Chapter 1 we present data from two years of field studies and two years of studies in the convertible glasshouse. In both systems we quantitatively counted the naturally occurring aphid population and collected parasitoid mummies for the construction of aphid parasitoid food webs. The aim of the study was to look if the genetic modification of the wheat lines affected parasitoid diversity and associated food web structures. In both years we found the three most common cereal aphid species M. dirhodum, R. padi and S. avenae and a total of 21 parasitoid species. Due to too few aphids and parasitoids present in the field, food web analysis was only conducted for the data collected in the convertible glasshouse. We found various significant effects of the different wheat lines on insect community structure up to the 4th trophic level. However, observed differences in the food web metrics were inconsistent between the two study years and there was as much variation between wheat varieties as there was between GMO lines and their controls within varieties. Consequently observed effects are likely to be of little ecological relevance. Chapter 2 describes a study where we looked at the impact of mildew-resistant wheat lines on different clone lines of the aphid M. dirhodum. The performance of 30 aphid clones on four different transgenic wheat lines and their four corresponding control lines was studied in a life-table experiment assessing a range of aphid life-history parameters. Looking at different aphid clones allowed us to assess whether impacts depended on aphid clone and whether there were aphid clone × wheat line interactions (genotype × environment). As expected we found significant clonal variation for all the measured life-history parameters. However, we did not find any major impact of the transgenic wheat lines on aphid performance except for a decrease of the total number of offspring by 3.33% produced on the GM lines compared to the control lines. There was no evidence for genotype × environment interactions. In sum, these results imply that there was no major difference in host plant quality of the GM lines compared to their control lines. In Chapter 3 we present the results of the insect monitoring including aphids, the chloropid gout fly and cereal leaf beetles. We assessed their abundance and the plant damage caused by them in the field and in the convertible glasshouse for two seasons. Besides the experimental wheat lines we also had a range of different commercially available wheat varieties as well as a Barley and a Triticale variety. We found that the transgenic Pm3b#1 line had higher aphid populations compared to their control line. This was only found in the convertible glasshouse where aphid abundance and mildew infection were much higher compared to the field. It appeared that this effect was due to the decreased mildew infection of the resistant Pm3b#1 lines and hence overall healthier plants. We provide further evidence for this in Chapter 4. We did not find differences between the GM wheat lines and the control lines for the other herbivores. Furthermore, the variation between the conventional wheat varieties and between the crops was much larger than between the experimental wheat lines. The study presented in Chapter 4 followed observations made in the field and the convertible glasshouse (Chapter 3) where we had seen that mildew infection seems to influence aphid performance: GM plants that had an increased resistance against powdery mildew and were thus less affected by the pathogen compared to their control lines carried larger aphid populations. To confirm this and learn more about the mechanism of this effect we conducted population experiments under controlled glasshouse conditions using the same experimental wheat lines and the two aphid species M. dirhodum and R. padi. We hypothesized that aphids feeding on infected plants will grow slower and will remain smaller compared to aphids on the non-infected plants. By combining three different, consecutive experiments we were able to clearly distinguish between variety effects, effects of the fungal pathogen and to exclude potential effects caused by the transformation process. We found that only M. dirhodum was affected by the presence of the fungal pathogen. In all three experiments, we found smaller population sizes on infected plants whereas R. padi remained mostly unaffected by powdery mildew but was sensitive to wheat variety. We showed that M. dirhodum simply reacts to mildew infection and that there is no direct effect of the introduced transgene whatsoever. ZUSAMMENFASSUNG Diese Doktorarbeit wurde im Rahmen des Weizen-Konsortiums durchgefĂŒhrt. Das Konsortium war Teil des Nationalen Forschungsprogram NFP 59 „Nutzen und Risiken der Freisetzung gentechnisch verĂ€nderter Pflanzen“. Das Weizen-Konsortium hat Feldexperimente mit verschiedenen ausgewĂ€hlten, Mehltau-resistenten, gentechnisch verĂ€nderten (GV) Sommerweizen-Linien durchgefĂŒhrt. In dieser Forschungsarbeit haben wir die Auswirkungen dieser GV Pflanzen auf pflanzenfressende Insekten und deren Antagonisten untersucht. Unter anderem haben wir uns mit BlattlĂ€usen und den mit ihnen assoziierten Nahrungsnetzen beschĂ€ftigt. Unsere Hypothese war, dass sich VerĂ€nderungen im Metabolismus der GV Pflanzen auf das Fressverhalten, das Wachstum und die Fitness von pflanzenfressenden Insekten und deren Feinden auswirken. Wir haben unsere Hypothese im Feld, einem halboffenen und einem konventionellen Glasshaus sowie in Klimakammern untersucht. Die Experimente im Feld und im halboffenen Glasshaus fokussierten sich auf natĂŒrlich vorkommende Herbivore und Blattlaus-Parasitoide Nahrungsnetze. ErgĂ€nzende Experimente im konventionellen Glasshaus und den Klimakammern wurden durchgefĂŒhrt, um mehr ĂŒber die Mechanismen zu erfahren, die die Pflanzen-Insekten-Interaktionen beeintrĂ€chtigen. Im Kapitel 1 prĂ€sentieren wir Daten von zwei Studienjahren im halboffenen GewĂ€chshaus und im Feld. In beiden Umgebungen haben wir die natĂŒrlich vorkommenden Blattlauspopulationen quantitativ erfasst und Parasitoidenmumien gesammelt um die Blattlaus-Parasitoiden Nahrungsnetze zu konstruieren. Das Ziel der Studie war herauszufinden, ob sich die gentechnische VerĂ€nderung der Weizenpflanzen auf ParasitoidendiversitĂ€t und die Struktur der Nahrungsnetze auswirkt. In beiden Jahren fanden wir die drei hĂ€ufigsten GetreideblattlĂ€use M. dirhodum, R. padi und S. avenae sowie insgesamt 21 Parasitoidenarten. Aufgrund zu niedriger Blattlaus- und Mumiendichten im Feld konnte die Analyse der Nahrungsnetze nur fĂŒr die Daten aus dem halboffenen GewĂ€chshaus gemacht werden. Wir fanden diverse Effekte der verschiedenen Weizenlinien auf die Insektengemeinschaft bis hinauf zur vierten trophischen Ebene. Jedoch waren diese Unterschiede inkonsistent zwischen den Studienjahren. Des Weiteren fanden wir gleich viel Variation zwischen den Weizen-Sorten wie zwischen den GV-Linien und den Kontrollinien innerhalb einer Sorte. Deshalb sind die beobachteten Unterschiede höchst wahrscheinlich von untergeordneter, ökologischer Relevanz. Kaptiel 2 beschreibt eine Studie in der wir die Auswirkungen von Mehltau-resistentem GV Weizen auf 30 verschiedene Klonlinien der Blattlaus M. dirhodum untersuchten. Die Blattlausklonlinien wurden auf vier unterschiedlichen GV Weizenlinien und deren dazugehörigen Kontrollinien gehalten und wir haben eine Reihe von Lebenstafel-Parameter untersucht. Indem wir unterschiedliche Klonlinien untersuchten, konnten wir unterscheiden, welche Effekte durch den Blattlausgenotyp bestimmt wurden und ob es Klonlinien × Weizenlinien Interaktionen gab (Genotyp × Umwelt). Wie erwartet, fanden wir signifikante klonale Variation fĂŒr alle Lebenstafel-Parameter. Wir fanden jedoch keinen grossen Einfluss der GV Weizenlinien auf die Biologie der BlattlĂ€use mit Ausnahme von einer um 3.33 % reduzierten Anzahl produzierter Nachkommen auf den GV Weizenlinien im Vergleich mit den Kontrollinien. Es gab keinen Nachweis fĂŒr Genotyp × Umwelt Interaktionen. Zusammenfassend zeigen diese Resultate, dass sich NahrungsqualitĂ€t der GV Wirtspflanzen verglichen mit den nicht GV Pflanzen fĂŒr BlattlĂ€use nicht entscheidend geĂ€ndert hat. In Kapitel 3 prĂ€sentieren wir Resultate vom Insektenmonitoring im Feld und im halboffenen GewĂ€chshaus. WĂ€hrend zwei Jahren wurden Vorkommen von BlattlĂ€usen, der Gelben Getreidehalmfliege und dem GetreidehĂ€hnchen sowie der Schaden der letzteren beiden erfasst. Neben den experimentellen GV Weizenpflanzen hatten wir auch eine Reihe kommerziell erhĂ€ltlicher Weizensorten sowie eine Gerste- und eine Triticalesorte im Versuch. Im GewĂ€chshaus, wo die Blattlausdichte und Mehltauinfektion höher war als im Feld, fanden wir mehr BlattlĂ€use auf der transgenen Pm3b#1 Linie verglichen mit deren Kontrollinie. Dies war vermutlich eine Folge des tieferen Mehltau-Befalls der resistenten Pm3b#1 Pflanzen und deren damit einhergehenden besseren Gesundheitszustandes. DafĂŒr erbringen wir in Kapitel 4 weitere Beweise. FĂŒr die anderen Herbivoren fanden wir keine Unterschiede zwischen den GV Pflanzen und ihren Kontrollen. Des Weiteren waren die Unterschiede zwischen den kommerziellen Sorten grösser, als zwischen den experimentellen Pflanzen. In Kapitel 4 sind wir der im Feld und im halboffenen Glasshaus gemachten Beobachtung nachgegangen, dass GV Pflanzen mit tieferen Mehltau-Infektionen mehr BlattlĂ€use zu beherbergen scheinen (Kapitel 3). Um diesen Zusammenhang zu bestĂ€tigen, haben wir im Glasshaus unter kontrollierten Bedingungen Populationsexperimente mit denselben Weizenlinien und den zwei Blattlausarten M. dirhodum und R. padi durchgefĂŒhrt. Unsere Hypothese war, dass BlattlĂ€use, die auf von Mehltau-befallenen Pflanzen fressen, langsamer wachsen und kleiner bleiben, im Vergleich zu BlattlĂ€usen, die auf gesunden Pflanzen fressen. Indem wir drei aufeinandefolgende Experimente durchfĂŒhrten, konnten wir klar zwischen Sorteneffekten und Mehltau-Effekten unterscheiden sowie potentielle GV-Effekte auschliessen. Metopolophium dirhodum war in allen drei Experimenten von der Anwesenheit des Pilzes betroffen und zeigte kleinere Populationsgrössen auf den infizierten Pflanzen. Rhopalosiphum padi reagierte grösstenteils nicht auf Mehltau, zeigte jedoch eine SortenabhĂ€ngikeit. Wir zeigten, dass M. dirhodum nur auf die Anwesenheit von Mehltau reagierte und dass die GV-Weizenlinien keinen direkten Einfluss haben
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