A comprehensive analysis of the importance of translation initiation factors for Haloferax volcanii applying deletion and conditional depletion mutants

Translation is an important step in gene expression. The initiation of translation is phylogenetically diverse, since currently five different initiation mechanisms are known. For bacteria the three initiation factors IF1 – IF3 are described in contrast to archaea and eukaryotes, which contain a considerably higher number of initiation factor genes. As eukaryotes and archaea use a non-overlapping set of initiation mechanisms, orthologous proteins of both domains do not necessarily fulfill the same function. The genome of Haloferax volcanii contains 14 annotated genes that encode (subunits of) initiation factors. To gain a comprehensive overview of the importance of these genes, it was attempted to construct single gene deletion mutants of all genes. In 9 cases single deletion mutants were successfully constructed, showing that the respective genes are not essential. In contrast, the genes encoding initiation factors aIF1, aIF2γ, aIF5A, aIF5B, and aIF6 were found to be essential. Factors aIF1A and aIF2β are encoded by two orthologous genes in H. volcanii. Attempts to generate double mutants failed in both cases, indicating that also these factors are essential. A translatome analysis of one of the single aIF2β deletion mutants revealed that the translational efficiency of the second ortholog was enhanced tenfold and thus the two proteins can replace one another. The phenotypes of the single deletion mutants also revealed that the two aIF1As and aIF2βs have redundant but not identical functions. Remarkably, the gene encoding aIF2α, a subunit of aIF2 involved in initiator tRNA binding, could be deleted. However, the mutant had a severe growth defect under all tested conditions. Conditional depletion mutants were generated for the five essential genes. The phenotypes of deletion mutants and conditional depletion mutants were compared to that of the wild-type under various conditions, and growth characteristics are discussed

Fluorescence correlation spectroscopy in thin films at reflecting substrates as a means to study nanoscale structure and dynamics at soft-matter interfaces

Structure and dynamics at soft-matter interfaces play an important role in nature and technical applications. Optical single-molecule investigations are non-invasive and capable to reveal heterogeneities at the nanoscale. In this work we develop an autocorrelation function (ACF) approach to retrieve tracer diffusion parameters obtained from fluorescence correlation spectroscopy (FCS) experiments in thin liquid films at reflecting substrates. This approach then is used to investigate structure and dynamics in 100 nm thick 8CB liquid crystal films on silicon wafers with five different oxide thicknesses. We find a different extension of the structural reorientation of 8CB at the solid-liquid interface for thin and for thick oxide. For the thin oxides, the perylenediimide tracer diffusion dynamics in general agrees with the hydrodynamic modeling using no-slip boundary conditions with only a small deviation close to the substrate, while a considerably stronger decrease of the interfacial tracer diffusion is found for the thick oxides.Comment: 8 figure

«Mein Lohn ist, dass ich darf» : wie Hausmütter den Machtverlust ihrer Position in Häusern für «Kranke und Pflegebedürftige» zwischen 1945 und 1995 im Rückblick erinnerten

Betriebsfamilien waren im 20. Jahrhundert weit verbreitet. Da kaum empirisches Material zur Funktion der Hausmutter existiert, sollte in einer qualitativen Studie untersucht werden, wie Mitglieder die Funktion der Hausmutter zwischen 1945 und 1995 erinnerten und wie gemeinschaftliches Leben in damaligen Betriebsfamilien möglich war. Methodisch orientierte sich das Vorgehen sowohl an dem Verfahren der Oral History und an den Ansätzen der Grounded Theory als auch an der sequenziellen Line-by-Line-Analysis. Betriebsfamilien waren im 20. Jahrhundert weit verbreitet. Da kaum empirisches Material zur Funktion der Hausmutter existiert, sollte in einer qualitativen Studie untersucht werden, wie Mitglieder die Funktion der Hausmutter zwischen 1945 und 1995 erinnerten und wie gemeinschaftliches Leben in damaligen Betriebsfamilien möglich war. Methodisch orientierte sich das Vorgehen sowohl an dem Verfahren der Oral History und an den Ansätzen der Grounded Theory als auch an der sequenziellen Line-by-Line-Analysis. Aus den Befragungen der Gesamtstudie (n = 42) wurden für den vorliegenden Artikel die Interviews mit neun Hausmüttern verwendet. Fokussiert wurde die Frage, wie Hausmütter berufsbezogene Entwicklungen im Rückblick erlebten und wie diese auf die Funktion der Hausmutter Einfluss genommen haben. Als Ergebnis konnten drei Phasen definiert werden, welche die Hausmutter mit ihrer Funktion durchlief. Dieser Artikel beschreibt die dritte Phase «Aus der Funktion der Hausmutter ausscheiden – verlorene und enttäuschte Macht und Herrschaft». Hausmütter waren nicht nur Hauswirtschafterinnen, sondern auch Pflegende, die mit ihrer Stellung im Haus neben dem Hausvater das betriebsfamiliale Oberhaupt bildeten. Mit den Mitgliedern der «Familie» in einem Haus zu leben belastete Hausmütter, gleichzeitig konnten sie aber davon profitieren, weil sie über viele Freiheiten verfügten, was mit der Kernkategorie Macht und Herrschaft beschrieben werden konnte. Institutional families were widespread in the 20th century. As there is very little empirical material on the function of the housemother, a qualitative study was launched to explore members' memories of the function of the housemother between 1945 and 1995 and how communal life in the institutional families of the period was possible. The study was methodologically oriented towards oral history techniques and the principles of Grounded Theory as well as towards sequential line by line analysis. For the purposes of this article, the interviews with nine housemothers were selected from the interviews conducted for the wider study (n = 42). The central question concerned how housemothers experienced professional developments in retrospect and the influence these had on the function of the housemother. The interviews resulted in the definition of three phases which the housemothers passed through during their role as housemother. This article describes the third phase: “Leaving the function of the housemother – lost and frustrated power and dominance”. Housemothers were not only housekeepers but also carers. Together with their husbands, they represented the heads of their institutional families. Housemothers found living in one house with the other members of the “family” a burden, but at the same time they benefitted from the great freedom they had. This aspect is described using the core categories of power and dominance

„…und dann fiel ich aus allen Wolken – das war tiefste Pionierarbeit“ : betriebsfamiliale Systeme am Beispiel der Hausmutter-Funktion – methodisch angelehnt an den Ansatz der Grounded Theory

Da bislang keine empirischen Ergebnisse zur Funktion der Hausmutter vorliegen, soll mit einer qualitativen Untersuchung, die dem Stil der Grounded Theory folgt, herausgefunden werden, wie sich die Hausmutter-Funktion in der zweiten Hälfte des 20. Jahrhunderts in der Interaktion mit Bewohnern gestaltete und welche Bedeutung ihr zugeschrieben wurde. Es konnten insgesamt neun Hausmütter und acht Hausväter für ein Oral-History-Interview (n = 17) gewonnen werden. Anhand der Ergebnisse konnten drei Phasen der Hausmutter-Funktion definiert werden, von denen im vorliegenden Bericht die zweite Phase: „Sich als Hausmutter verwirklichen – umgesetzte Macht und Herrschaft“ fokussiert wird. Die Ergebnisse zeigen, dass Hausmüttern mit der Kernkategorie: „Macht und Herrschaft“ ein großes Potential oblag, Entscheidungen für die im Haus Lebenden zu treffen, was sich anhand von Machtformen und Stabilisierungsformen der Macht veranschaulichen lässt. Vielfach haben sich Hausmütter eingesetzt, Bedingungen für eine bessere Pflege zu verändern. Die Ergebnisse der Studie können helfen, gemeinschaftliches Leben zu reflektieren, da die Phänomene „Macht und Herrschaft“ in der pflegerischen Versorgung bis heute an Aktualität nicht verloren haben. Empirical results concerning the function of house-mothers do not exist. This qualitative study was designed to establish the nature and importance of interactions between house-mothers and occupants for the second half of the 20th century. A sample of nine house-mothers and eight house-fathers were recruited with whom it was possible to conduct oral history interviews (n=17). Analysis of the data revealed three functional phases of their work, with this paper dealing with the second, “Fulfilling one’s potential as a house-mother – implementation of power and dominance”. Results in the main category of power and dominance showed them having a high incidence of decision making for the house residents, an illustration of the power/stabilisation model of power House-mothers reported the need for changes in care provisions to improve the quality of services, a reflection on their own functional activity. This finding is relevant because it would appear that the phenomena of power and dominance has not lost its significance for communal living, even in the 21st century

Preferences for School Milk - How Juveniles Differ

Snacks and lunches offered at school can decisively influence children’s dietary habits. In the light of discussions to establish prevention and intervention programs to abate current trends of rising childhood obesity, children’s preferences for food items with lower calorie content gain on importance. But youths preferences concerning different school milk products are not well-known. Therefore, the objective is to investigate if the milk products offered at school still meet older children’s preferences or if modifications could prove to be useful. Based on outcomes of an online survey covering a choice experiment and conducted among juveniles in Germany the probability that youths benefit from different products as well as varying prices, sugar and fat contents is estimated. Socio-demographics, psycho-metrics and perceived weight status are employed to explain youths choices preferring novel school milk products yet unavailable in German schools. Results of the choice experiment show that youths aged 15-18 are a heterogeneous group. They prefer a wider range of different products including drinking yoghurt as an option as well. Results indicate that nutritional aspects (low sugar/fat content, artificial sweetener) and body image are important for some of them

What is the benefit of organically-reared dairy cattle? Societal perception towards conventional and organic dairy farming

During the last years, current systems in agriculture and food production have been topic in public discussions. Especially modern animal husbandry seems not to match consumers’ or societal needs any longer. This paper concentrates on the society’s perspective regarding dairy farming in general and diverting perceptions and expectations with respect to dairy cattle either reared organically or reared conventionally. It aims to give orientation to farmers as well as policymakers about the societal point of view of dairy farming.Six focus groups were carried out in three German cities to capture the scope of opinions and expectations among the population. Three of those groups consisted of participants buying mainly organic food while the other three comprised citizens buying mainly conventional food.With respect to society’s perception of today’s dairy farming results showed that participants put emphasis on the following topics: the space for each cow was considered as insufficient and not species-appropriate, assumed application of medications as too high, and in particular the prophylactic use of antibiotics as problematic.Asked about perceived differences between organic versus conventional farming it became obvious that organic in contrast to the conventional farming was perceived as more species-appropriate. More or less, all previously criticized aspects seem to be regarded as irrelevant in organic farming. Some participants showed a very romantic view of organic dairy farming. The most critical point was an assumed high rate of rogue traders among organic farmers

What is the benefit of organically-reared dairy cattle? Societal perception towards conventional and organic dairy farming

During the last years, current systems in agriculture and food production have been topic in public discussions. Especially modern animal husbandry seems not to match consumers’ or societal needs any longer. This paper concentrates on the society’s perspective regarding dairy farming in general and diverting perceptions and expectations with respect to dairy cattle either reared organically or reared conventionally. It aims to give orientation to farmers as well as policymakers about the societal point of view of dairy farming.Six focus groups were carried out in three German cities to capture the scope of opinions and expectations among the population. Three of those groups consisted of participants buying mainly organic food while the other three comprised citizens buying mainly conventional food.With respect to society’s perception of today’s dairy farming results showed that participants put emphasis on the following topics: the space for each cow was considered as insufficient and not species-appropriate, assumed application of medications as too high, and in particular the prophylactic use of antibiotics as problematic.Asked about perceived differences between organic versus conventional farming it became obvious that organic in contrast to the conventional farming was perceived as more species-appropriate. More or less, all previously criticized aspects seem to be regarded as irrelevant in organic farming. Some participants showed a very romantic view of organic dairy farming. The most critical point was an assumed high rate of rogue traders among organic farmers

Does everyone reject modern pig production? Identification and characterisation of societal groups in Germany

Today’s agriculture and food production has been topic in public discussions and the media in the last years. Societal perceptions and imaginations of agriculture seem to be far away from reality. There is no indication of a declining gap between consumers’ expectations and their perception of animal husbandry. However, precise information about expectations and priorities of the population are unknown. Thus, the paper concentrates on society’s views and opinions. On the example of intensive pig production, the objective of the study is to analyse societal perceptions, expectations and main points of criticism. It also aims on the identification and characterisation of societal groups with almost identical attitudes.By combining exploratory focus groups with a quantitative survey, a mixed method approach is pursued. Focus groups are carried out in September 2012 in three German cities to capture a variety of opinions and concerns among the population. On the basis of findings from focus groups a quantitative survey is carried out in spring 2013 per online survey with approximately 1500 German citizens to quantify qualitative results.The surveys’ findings confirmed many of the critical views gained in the focus groups. On the basis of four extracted attitudinal factors three groups with heterogeneous opinions are differentiated with respect to modern pig production. Besides a very engaged group which is characterised by a strong criticism in general and a strong critical perception of current production systems, also a considerable group accepting modern animal husbandry was identified. The multinomial logit regression finally allows for a characterisation of the identified societal segments by sociodemographic and regional aspects. Additionally, the question of responsibility and the acceptance of consequences of several governmental actions are included in the model. It turns out that gender and agricultural knowledge of the people are significant determinants in explaining cluster membership. Interestingly, opponents more often have a good knowledge of agriculture. These findings imply that negative attitudes cannot be traced back to a missing knowledge

Regulation von PD-L1 und dessen zellintrinsische Funktion für die Vermittlung von Radioresistenz im Kopf-Hals-Tumor

Derzeit hat eine gezielte Blockade der PD-1/PD-L1-Achse die Behandlung verschiedener Tumorentitäten verbessert, einschließlich des Plattenepithelkarzinoms im Kopf-Hals-Bereich (HNSCC). Ein Teil der Patientenkohorte zeigt jedoch immer noch wenig Verbesserung oder sogar Hyperprogression. Die Bestrahlung wird derzeit als synergistische Behandlungsmodalität zur Immuntherapie untersucht, da sie die Anzahl der T-Zellen erhöht und damit die Wirksamkeit der Immuntherapie steigert. Abgesehen von diesem immunologischen Kontext weisen immer mehr Daten darauf hin, dass PD-L1 auch eine zellintrinsische Rolle in Tumorzellen vermittelt, indem es verschiedene zelluläre Funktionen wie Zellproliferation oder Migration reguliert. Ziel dieser Arbeit war es, die Regulation von PD-L1 in Kopf-Hals-Tumoren weiter aufzuklären, Erklärungsansätze für Therapieversagen zu finden und Ideen für zukünftige Kombinationsstrategien zu liefern