Analyses of vesicular transport within the endoplasmic reticulum-golgi interface in "Saccharomyces cerevisiae"

A characteristic feature of every eukaryotic cell is its division into different compartments. This subdivision into different intracellular organelles like the endoplasmic reticulum (ER), the Golgi apparatus or the endosomal/lysosomal system enables cells to provide the appropriate environment for a great variety of biochemical processes. However, it also necessitates an elaborate machinery for the communication between these compartments or organelles. On one hand, material has to be exchanged between organelles, but on the other hand, their integrity with respect to their protein and lipid content, has to be maintained to fulfil their function. Transport processes between different organelles are mediate by intracellular traffic pathways. Proteins enter the secretory pathway at the ER, where they acquire first posttranslational modifications. From the ER, they are delivered to the Golgi, where they are further modified and sorted to their target compartments. In the secretory pathway, transport carriers, so-called vesicles, bud from one organelle (donor) and fuse with the next organelle (acceptor) along their trafficking route. Understanding the molecular mechanisms and regulations underlying vesicular transport is crucial and therefore has been a main topic of research over the last decades. The machinery required for budding and fusion of vesicles along their trafficking pathways is conserved from yeast to human. Therefore, the yeast Saccharomyces cerevisiae represents a suitable organism to study the secretory pathway. In this thesis, we used S. cerevisiae to examine the regulation of vesicular traffic at the ER-Golgi interface, more specifically the fusion of vesicles with ER membranes. The consumption of a vesicle at its target membrane is mediated by the orchestrated action of various members of conserved protein families that act in a regulated manner. Main players involved in vesicular fusion are Rab GTPases, tethering factors and SNAREs. The tethering factors and the Rab GTPases mediate the first contact of an incoming vesicle with its acceptor organelle, whereas the SNARE proteins are responsible for the final fusion event between vesicles and target membranes. Here, we identified the Rab GTPase Ypt1p as mediator of vesicle fusion with the ER. Moreover, Ypt1p was not only required for vesicle fusion at the ER, but also for the maintenance of the morphology and protein composition of the Golgi, and for vesicle formation at the Golgi. In addition, the tethering complex responsible for the docking of Golgi-derived vesicles with the ER, the Dsl1 tethering complex was analyzed. We found that this complex, apart from mediating the first contact of the incoming vesicles with the ER membrane, seems to play an additional role in proofreading and stabilization of SNARE complexes that are responsible for vesicle fusion at the E

Comparing Digit Morphology of an Arboreal Salamander with Potential Competitors

Green Salamanders (Aneides aeneus) are the only salamanders in West Virginia to exhibit an arboreal lifestyle. The focus of this study was to determine the cellular anatomy of the distal digit structures and how these structures may influence climbing ability. Comparative histology, comparative morphometrics, and comparative osteology of Green Salamanders, Cumberland Plateau Salamanders (Plethodon kentucki), and Slimy Salamanders (Plethodon glutinosus), were also used to determine if Cumberland Plateau Salamanders had the potential to compete with Green Salamanders for arboreal habitats. Histologically, Cumberland Plateau Salamanders had cell layer thickening similar to that of Green Salamanders. Morphometrically, Green Salamanders and Cumberland Plateau Salamanders had similar limb measurements; however Cumberland Plateau Salamanders were larger in trunk height and tail height. Osteologically, Cumberland Plateau Salamanders and Slimy Salamanders were virtually identical in carpal, tarsal, and terminal phalanx structure and arrangement

prosperity, happiness or growth: claims for a new national accountancy in the 21st century.

The task of reaching a more sustainable kind of economic process is narrowly related with a double problem: up to date most societies have pursued an explicit strategy of economic growth, although its successes are now disappearing and, at a closer look, its negative ecological and social side effects appear to be even growing. The first part of this article contrasts the ambiguity of the growth concept with a concept of social welfare, which aims at a more qualitative kind of growth, considering the available natural and social capital as well. It will become clear that even GDP as a traditional and politically crucial indicator for the success or failure of a country’s economic development necessarily gives ambiguous signals if one looks at this parameter of the national accounts by the light of a sustainable development. More recent calculations of the national welfare index for Germany (NWI) result in some interesting discussion lines: the aggregated progress of 19 variables shows an significant difference in its development: between 2000 and 2007, the NWI tends to fall in comparison with GDP/GNI (gross national income). This discrepancy is to be seen as evidence of the fact that there might be an increasing economic growth even without any improvement in welfare. Quite on the contrary, in the years 2008 – 2009 the NWI does not seem to follow the drastic collapse of GDP/GNI at the same pace. This article aims at providing an overview both of the social context in which NWI was created as a complementary reporting system integrating GDP/GNI and of its construction principles as well as of some results. From all this, some conclusions will be drawn about how the index can be helpful in the development of a more sustainable concept of welfare. For example, it will become understandable that improvements in welfare can be achieved even without economic growth. This process could go hand in hand with reflections on economic transformation and cultural change. It is all about future strategies allowing a reduction in the physical material and energy flux as well as in the negative impacts on ecosystems and nature due to economic activities, so that societies will profit from such change

Refining Fast Calorimeter Simulations with a Schr\"{o}dinger Bridge

Machine learning-based simulations, especially calorimeter simulations, are promising tools for approximating the precision of classical high energy physics simulations with a fraction of the generation time. Nearly all methods proposed so far learn neural networks that map a random variable with a known probability density, like a Gaussian, to realistic-looking events. In many cases, physics events are not close to Gaussian and so these neural networks have to learn a highly complex function. We study an alternative approach: Schr\"{o}dinger bridge Quality Improvement via Refinement of Existing Lightweight Simulations (SQuIRELS). SQuIRELS leverages the power of diffusion-based neural networks and Schr\"{o}dinger bridges to map between samples where the probability density is not known explicitly. We apply SQuIRELS to the task of refining a classical fast simulation to approximate a full classical simulation. On simulated calorimeter events, we find that SQuIRELS is able to reproduce highly non-trivial features of the full simulation with a fraction of the generation time.Comment: 10 pages, 5 figure

Habit formation in context: Context‐specific and context‐free measures for tracking fruit consumption habit formation and behaviour

Objectives: Interventions promoting habitual fruit consumption have the potential to bring about long-term behaviour change. Assessing the effectiveness of such interventions requires adequate habit and behaviour measures. Habits are based on learned context-behaviour associations, so measures that incorporate context should be more sensitive to expected habit and behaviour changes than context-free measures. This study compared context-specific and context-free measures of fruit consumption habit and behaviour following a 3-week habit formation intervention. / Design: Prospective online study (n = 58). / Methods: Behaviour frequency was assessed across five timepoints, retrospectively (Time 1 [T1], T5) or via daily diary data (uploaded weekly at T2, T3 and T4). Habit strength was assessed before (T1) and immediately after the intervention (T4), and again 2 weeks later (T5). Analyses of variance were run, with time and context specificity as within-subject factors, and habit and behaviour frequency as dependent measures. / Results: An interaction between time and context specificity was found in both analyses (habit: F(2,114) = 12.848, p < .001, part.η2 = .184; behaviour: F(2,114) = 6.714, p = .002, part.η2 = .105). Expected habit formation patterns 5 weeks post-baseline were only detected by the context-specific habit measure. Likewise, increased behaviour frequency was only found when the target context was specified (p's < .001). / Conclusions: Assessments of purposeful dietary habit and behaviour change attempts should incorporate context-specific measurement

Notes on the Distribution and Natural History of the Eastern Wormsnake (Carphophis amoenus amoenus) in West Virginia

Small fossorial snakes, such as the Eastern Wormsnake (Carphophis amoenus amoenus), are often neglected in studies since they lead a fossorial life and are frequently hard to find. Since it was last studied nearly 40 years ago, we present an update on distribution, habitat preferences, and diet of the Eastern Wormsnake in West Virginia. We found that this species resides in only a fraction of its original range due to habitat destruction by industrial, residential, and commercial developments. Habitat data suggests this species can tolerate a range of soil temperatures (15–24 °C), air temperatures (23.1 degrees Celsius), and relative humidity (24.5-80%), and can be found on nearly all slope directions. Dietary analysis showed annelids make up the majority of their diet but other invertebrate prey are also taken

Sustainable Development - Einige Anmerkungen zu den Problemen eines Begriffs

Die Vereinigung flir ökologische Wirtschaftsforschung (VÖW) beabsichtigt, ihre Jahrestagung 1992 zum Thema " Ökologie und Entwicklung " auszurichten. Je unwahrscheinlicher es ist, daß sich Dinge schnell ändern, desto wichtiger ist es, sie miteinander zu besprechen. Der folgende Beitrag will nur ei-nige Stolpersteine benennen, die jeder Diskussionzum Thema "Sustainable Development" im Weg lie-gen können. Er will außerdem zeigen, warum es wichtig ist, sich zunächst über Rahmenbedingungen zu verständigen, innerhalb derer dann eine Diskussion über die Inhalte des Begriffs geführt werden muß

Umweltbezogene Gerechtigkeit: Ansätze zur statistischen Messung

"Der Beitrag versucht zunächst zu zeigen, dass Umweltgerechtigkeit in den bislang vorliegenden empirischen Arbeiten im Grunde überwiegend als Gleichheit begriffen wurde. Es wird sodann argumentiert, dass es - wenn der Begriff mehr als ein nur temporärer Modebegriff sein soll - notwendig ist, seine Operationalisierung an den Erkenntnisstand der theoretischen Diskussion um den Begriff der Gerechtigkeit zurückzubinden. Es wird die These aufgestellt, dass der 'Capability-Ansatz' von Amartya Sen sich hier als ein möglicher Zugangsweg erweisen könnte. Neben der Möglichkeit, Indikatoren der Umweltgerechtigkeit auf kommunaler und regionaler Ebene anzuwenden, erscheint eine Integration des Konzepts in das nationale System der umweltökonomischen Gesamtrechnung (UGR) - etwa als ein eigenständiges Modul - als eine wichtige Möglichkeit, das Konzept der Umweltgerechtigkeit in den etablierten statistischen Berichtssystemen zu verankern. Vor diesem Hintergrund wird im zweiten Teil des Beitrages ein Ansatz der Operationalisierung des Begriffs in Form von Indikatoren zur Diskussion gestellt, das die Anforderung der Kompatibilität für die verschiedenen Ebenen - kommunal, regional und national - erfüllen könnte. Abschließend wird erörtert, inwieweit diese Form der Operationalisierung sich für eine Integration in die UGR als Satellitensystem zur Volkswirtschaftlichen Gesamtrechnung der Bundesrepublik Deutschland tatsächlich eignen könnte." (Autorenreferat