Braunschweig University of Technology

About: Braunschweig University of Technology is a education organization based out in Braunschweig, Germany. It is known for research contribution in the topics: Population & Solar wind. The organization has 13268 authors who have published 26707 publications receiving 611590 citations.

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Abstract: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure flux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation, it is imperative to target by gene knockout or RNA interference more than one autophagy-related protein. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways implying that not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular assays, we hope to encourage technical innovation in the field.

Computable measure of entanglement

Abstract: We present a measure of entanglement that can be computed effectively for any mixed state of an arbitrary bipartite system. We show that it does not increase under local manipulations of the system, and use it to obtain a bound on the teleportation capacity and on the distillable entanglement of mixed states.

The People's Choice: How the Voter Makes Up His Mind in a Presidential Campaign

Abstract: Die von Paul F. Lazarsfeld, Bernard Berelson und Hazel Gaudet 1944 veroffentlichte Studie The people’s choice untersucht den Prasidentschaft swahlkampf in den USA 1940. Analysiert wird: „How the voter makes up his mind in a presidential campaign”. Die Entstehung individueller Wahlentscheidungen und der Einfluss von Informationen verschiedener Quellen, u. a. der Medien wurden mittels eines fur die Zeit revolutionaren Paneldesigns untersucht. Die Studie begrundet einen Meilenstein in der kommunikationswissenschaftlichen Forschung, da sie den Grundstein fur einen Paradigmenwechsel legt, namlich die Abkehr von der Annahme des Publikums als Masse, die den Einflussen der Massenmedien ausgeliefert ist, hin zu den „limited effects“ der Medien. Ausschlaggebend fur diesen Paradigmenwechsel waren drei in The people’s choice vorgestellte Konzepte, die auch heute noch in der Kommunikationswissenschaft diskutiert werden: Die These der selektiven Zuwendung des Publikums zu Medieninhalten, das Konzept der Meinungsfuhrer und die These vom Zweistufenfluss der Kommunikation. In diesem Beitrag werden der Inhalt des Werkes sowie die Kritik daran mit Fokus auf diese drei Konzepte vorgestellt.

The worst-case execution-time problem—overview of methods and survey of tools

Abstract: The determination of upper bounds on execution times, commonly called worst-case execution times (WCETs), is a necessary step in the development and validation process for hard real-time systems. This problem is hard if the underlying processor architecture has components, such as caches, pipelines, branch prediction, and other speculative components. This article describes different approaches to this problem and surveys several commercially available tools1 and research prototypes.