Showing papers by "Free University of Berlin published in 2010"

Helical Liquids and Majorana Bound States in Quantum Wires

Abstract: We show that the combination of spin-orbit coupling with a Zeeman field or strong interactions may lead to the formation of a helical electron liquid in single-channel quantum wires, with spin and velocity perfectly correlated. We argue that zero-energy Majorana bound states are formed in various situations when such wires are situated in proximity to a conventional s-wave superconductor. This occurs when the external magnetic field, the superconducting gap, or, most simply, the chemical potential vary along the wire. These Majorana states do not require the presence of a vortex in the system. Experimental consequences of the helical liquid and the Majorana states are also discussed.

Customer Engagement Behavior: Theoretical Foundations and Research Directions

Abstract: This article develops and discusses the concept of customer engagement behaviors (CEB), which we define as the customers’ behavioral manifestation toward a brand or firm, beyond purchase, resulting from motivational drivers. CEBs include a vast array of behaviors including word-of-mouth (WOM) activity, recommendations, helping other customers, blogging, writing reviews, and even engaging in legal action. The authors develop a conceptual model of the antecedents and consequences — customer, firm, and societal — of CEBs. The authors suggest that firms can manage CEBs by taking a more integrative and comprehensive approach that acknowledges their evolution and impact over time.

Customer engagement behavior : Theoretical foundations and research directions

Abstract: This article develops and discusses the concept of customer engagement behaviors (CEB), which we define as the customers’ behavioral manifestation toward a brand or firm, beyond purchase, resulting from motivational drivers. CEBs include a vast array of behaviors including word-of-mouth (WOM) activity, recommendations, helping other customers, blogging, writing reviews, and even engaging in legal action. The authors develop a conceptual model of the antecedents and consequences—customer, firm, and societal—of CEBs. The authors suggest that firms can manage CEBs by taking a more integrative and comprehensive approach that acknowledges their evolution and impact over time.

Microbiota and SCFA in Lean and Overweight Healthy Subjects

Abstract: Obesity has recently been linked to the composition of human microbiota and the production of short chain fatty acids (SCFAs). However, these findings rely on experimental studies carried out using rather small and defined groups of volunteers or model animals. Our aim was to evaluate differences within the human intestinal microbiota and fecal SCFA concentration of lean and obese subjects. A total of 98 subjects volunteered to take part in this study. The BMI in kg/m(2) of 30 volunteers was within the lean range, 35 were overweight and 33 were obese. The fecal microbiota was characterized by real-time PCR analyses. With the primers used herein we were able to cover 82.3% (interquartile range of 68.3-91.4%) of the total microbiota detectable with a universal primer. In addition, the concentration of SCFA was evaluated. The total amount of SCFA was higher in the obese subject group (P = 0.024) than in the lean subject group. The proportion of individual SCFA changed in favor of propionate in overweight (P = 0.019) and obese subjects (P = 0.028). The most abundant bacterial groups in faeces of lean and obese subjects belonged to the phyla Firmicutes and Bacteroidetes. The ratio of Firmicutes to Bacteroidetes changed in favor of the Bacteroidetes in overweight (P = 0.001) and obese subjects (P = 0.005). Our results are in line with previous reports suggesting that SCFA metabolism might play a considerable role in obesity. However, our results contradict previous reports with regard to the contribution of various bacterial groups to the development of obesity and this issue remains controversial.

The Mechanism of Water Oxidation: From Electrolysis via Homogeneous to Biological Catalysis

Abstract: Striving for new solar fuels, the water oxidation reaction currently is considered to be a bottleneck, hampering progress in the development of applicable technologies for the conversion of light into storable fuels. This review compares and unifies viewpoints on water oxidation from various fields of catalysis research. The first part deals with the thermodynamic efficiency and mechanisms of electrochemical water splitting by metal oxides on electrode surfaces, explaining the recent concept of the potential-determining step. Subsequently, novel cobalt oxide-based catalysts for heterogeneous (electro)catalysis are discussed. These may share structural and functional properties with surface oxides, multinuclear molecular catalysts and the catalytic manganese–calcium complex of photosynthetic water oxidation. Recent developments in homogeneous water-oxidation catalysis are outlined with a focus on the discovery of mononuclear ruthenium (and non-ruthenium) complexes that efficiently mediate O2 evolution from water. Water oxidation in photosynthesis is the subject of a concise presentation of structure and function of the natural paragon—the manganese–calcium complex in photosystem II—for which ideas concerning redox-potential leveling, proton removal, and OO bond formation mechanisms are discussed. The last part highlights common themes and unifying concepts.

Genome Sequence of the Pea Aphid Acyrthosiphon pisum

Abstract: Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we highlight findings from whole genome analysis that may be related to these unusual biological features. These findings include discovery of extensive gene duplication in more than 2000 gene families as well as loss of evolutionarily conserved genes. Gene family expansions relative to other published genomes include genes involved in chromatin modification, miRNA synthesis, and sugar transport. Gene losses include genes central to the IMD immune pathway, selenoprotein utilization, purine salvage, and the entire urea cycle. The pea aphid genome reveals that only a limited number of genes have been acquired from bacteria; thus the reduced gene count of Buchnera does not reflect gene transfer to the host genome. The inventory of metabolic genes in the pea aphid genome suggests that there is extensive metabolite exchange between the aphid and Buchnera, including sharing of amino acid biosynthesis between the aphid and Buchnera. The pea aphid genome provides a foundation for post-genomic studies of fundamental biological questions and applied agricultural problems.

Solar influences on climate

Abstract: The development of this review article has evolved from work carried out by an international team of the International Space Science Institute (ISSI), Bern, Switzerland, and from work carried out under the auspices of Scientific Committee on Solar Terrestrial Physics (SCOSTEP) Climate and Weather of the Sun‐Earth System (CAWSES‐1). The support of ISSI in providing workshop and meeting facilities is acknowledged, especially support from Y. Calisesi and V. Manno. SCOSTEP is acknowledged for kindly providing financial assistance to allow the paper to be published under an open access policy. L.J.G. was supported by the UK Natural Environment Research Council (NERC) through their National Centre for Atmospheric Research (NCAS) Climate program. K.M. was supported by a Marie Curie International Outgoing Fellowship within the 6th European Community Framework Programme. J.L. acknowledges support by the EU/FP7 program Assessing Climate Impacts on the Quantity and Quality of Water (ACQWA, 212250) and from the DFG Project Precipitation in the Past Millennium in Europe (PRIME) within the Priority Program INTERDYNAMIK. L.H. acknowledges support from the U.S. NASA Living With a Star program. G.M. acknowledges support from the Office of Science (BER), U.S. Department of Energy, Cooperative Agreement DE‐FC02‐97ER62402, and the National Science Foundation. We also wish to thank Karin Labitzke and Markus Kunze for supplying an updated Figure 13, Andrew Heaps for technical support, and Paul Dickinson for editorial support. Part of the research was carried out under the SPP CAWSES funded by GFG. J.B. was financially supported by NCCR Climate–Swiss Climate Research.

The genome of a songbird

Abstract: The zebra finch is an important model organism in several fields with unique relevance to human neuroscience. Like other songbirds, the zebra finch communicates through learned vocalizations, an ability otherwise documented only in humans and a few other animals and lacking in the chicken-the only bird with a sequenced genome until now. Here we present a structural, functional and comparative analysis of the genome sequence of the zebra finch (Taeniopygia guttata), which is a songbird belonging to the large avian order Passeriformes. We find that the overall structures of the genomes are similar in zebra finch and chicken, but they differ in many intrachromosomal rearrangements, lineage-specific gene family expansions, the number of long-terminal-repeat-based retrotransposons, and mechanisms of sex chromosome dosage compensation. We show that song behaviour engages gene regulatory networks in the zebra finch brain, altering the expression of long non-coding RNAs, microRNAs, transcription factors and their targets. We also show evidence for rapid molecular evolution in the songbird lineage of genes that are regulated during song experience. These results indicate an active involvement of the genome in neural processes underlying vocal communication and identify potential genetic substrates for the evolution and regulation of this behaviour.

Rooting theories of plant community ecology in microbial interactions

Abstract: Predominant frameworks for understanding plant ecology have an aboveground bias that neglects soil micro-organisms. This is inconsistent with recent work illustrating the importance of soil microbes in terrestrial ecology. Microbial effects have been incorporated into plant community dynamics using ideas of niche modification and plant–soil community feedbacks. Here, we expand and integrate qualitative conceptual models of plant niche and feedback to explore implications of microbial interactions for understanding plant community ecology. At the same time we review the empirical evidence for these processes. We also consider common mycorrhizal networks, and propose that these are best interpreted within the feedback framework. Finally, we apply our integrated model of niche and feedback to understanding plant coexistence, monodominance and invasion ecology.

Oxytocin Enhances Amygdala-Dependent, Socially Reinforced Learning and Emotional Empathy in Humans

Abstract: Oxytocin (OT) is becoming increasingly established as a prosocial neuropeptide in humans with therapeutic potential in treatment of social, cognitive, and mood disorders. However, the potential of OT as a general facilitator of human learning and empathy is unclear. The current double-blind experiments on healthy adult male volunteers investigated first whether treatment with intranasal OT enhanced learning performance on a feedback-guided item-category association task where either social (smiling and angry faces) or nonsocial (green and red lights) reinforcers were used, and second whether it increased either cognitive or emotional empathy measured by the Multifaceted Empathy Test. Further experiments investigated whether OT-sensitive behavioral components required a normal functional amygdala. Results in control groups showed that learning performance was improved when social rather than nonsocial reinforcement was used. Intranasal OT potentiated this social reinforcement advantage and greatly increased emotional, but not cognitive, empathy in response to both positive and negative valence stimuli. Interestingly, after OT treatment, emotional empathy responses in men were raised to levels similar to those found in untreated women. Two patients with selective bilateral damage to the amygdala (monozygotic twins with congenital Urbach-Wiethe disease) were impaired on both OT-sensitive aspects of these learning and empathy tasks, but performed normally on nonsocially reinforced learning and cognitive empathy. Overall these findings provide the first demonstration that OT can facilitate amygdala-dependent, socially reinforced learning and emotional empathy in men.

Modeling and Tools for Network Simulation

Abstract: A crucial step during the design and engineering of communication systems is the estimation of their performance and behavior; especially for mathematically complex or highly dynamic systems network simulation is particularly useful. This book focuses on tools, modeling principles and state-of-the art models for discrete-event based network simulations, the standard method applied today in academia and industry for performance evaluation of new network designs and architectures. The focus of the tools part is on two distinct simulations engines: OmNet++ and ns-3, while it also deals with issues like parallelization, software integration and hardware simulations. The parts dealing with modeling and models for network simulations are split into a wireless section and a section dealing with higher layers. The wireless section covers all essential modeling principles for dealing with physical layer, link layer and wireless channel behavior. In addition, detailed models for prominent wireless systems like IEEE 802.11 and IEEE 802.16 are presented. In the part on higher layers, classical modeling approaches for the network layer, the transport layer and the application layer are presented in addition to modeling approaches for peer-to-peer networks and topologies of networks. The modeling parts are accompanied with catalogues of model implementations for a large set of different simulation engines. The book is aimed at master students and PhD students of computer science and electrical engineering as well as at researchers and practitioners from academia and industry that are dealing with network simulation at any layer of the protocol stack.

Dendritic polyglycerols for biomedical applications.

Abstract: The application of nanotechnology in medicine and pharmaceuticals is a rapidly advancing field that is quickly gaining acceptance and recognition as an independent area of research called "nanomedicine". Urgent needs in this field, however, are biocompatible and bioactive materials for antifouling surfaces and nanoparticles for drug delivery. Therefore, extensive attention has been given to the design and development of new macromolecular structures. Among the various polymeric architectures, dendritic ("treelike") polymers have experienced an exponential development due to their highly branched, multifunctional, and well-defined structures. This Review describes the diverse syntheses and biomedical applications of dendritic polyglycerols (PGs). These polymers exhibit good chemical stability and inertness under biological conditions and are highly biocompatible. Oligoglycerols and their fatty acid esters are FDA-approved and are already being used in a variety of consumer applications, e.g., cosmetics and toiletries, food industries, cleaning and softening agents, pharmaceuticals, polymers and polymer additives, printing photographing materials, and electronics. Herein, we present the current status of dendritic PGs as functional dendritic architectures with particular focus on their application in nanomedicine, in drug, dye, and gene delivery, as well as in regenerative medicine in the form of non-fouling surfaces and matrix materials.

Light pollution as a biodiversity threat.

Abstract: In a recent TREE article, Sutherland and colleagues [1] used horizon scanning to identify fifteen emerging issues in biodiversity conservation. They discussed both threats and opportunities for a broad range of issues, including invasive species, synthetic meat, nanosilver and microplastic pollution. We recognize that the article was not intended to be comprehensive, but feel they overlooked an emerging problem of great importance and urgency, namely that of light pollution. Although the widespread use of artificial light at night has enhanced the quality of human life and is positively associated with security, wealth and modernity, the rapid global increase of artificial light has fundamentally transformed nightscapes over the past six decades, both in quantity (6% increase per year, range: 0–20%) and quality (i.e.

En passant mutagenesis: a two step markerless red recombination system.

Abstract: Bacterial artificial chromosomes are used to maintain and modify large sequences of different origins in Escherichia coli. In addition to RecA-based shuttle mutagenesis, Red recombination is commonly used for sequence modification. Since foreign sequences, such as antibiotic resistance genes as well as frt- or loxP-sites are often unwanted in mutant BAC clones, we developed a Red-based technique that allows for the scarless generation of point mutations, deletions, and insertion of smaller and larger sequences. The method employs a sequence duplication that is inserted into the target sequence in the first recombination step and the excision of the selection marker by in vivo I-SceI cleavage and the second Red recombination. To allow for convenient and highly efficient mutagenesis without the use of additional plasmids, the E. coli strain GS1783 with a chromosomal encoded inducible Red- and I-SceI-expression was created.

Governance without a state: Can it work?

Abstract: In this article we explore how much state is necessary to make governance work. We begin by clarifying concepts of governance and the “shadow of hierarchy” and we follow this clarification with a brief overview of empirical findings on governance research in developed countries. We then discuss the dilemmas for governance in areas of limited statehood, where political institutions are too weak to hierarchically adopt and enforce collectively binding rules. While prospects for effective policymaking appear to be rather bleak in these areas, we argue that governance research has consistently overlooked the existence of functional equivalents to the shadow of hierarchy. We assert that governance with(out) government can work even in the absence of a strong shadow of hierarchy, we identify functional equivalents to the shadow of hierarchy, and we discuss to what extent they can help overcome issues of legitimacy and effectiveness in areas of limited statehood.

CROSSROADS---Organizing for Fluidity? Dilemmas of New Organizational Forms

Abstract: An important new stream of thought stressing the importance of organizational fluidity has emerged in recent years. It represents a reaction to the increasing complexity and environmental turbulence that organizations have to master. The solutions proposed are highly flexible and fluid organizational forms, based on relentlessly changing templates, quick improvisation, and ad hoc responses. This approach is in sharp contrast to other recent organizational research that emphasizes identity, path dependence, economies of specialization, and recursive practices. We juxtapose the idea of organizational fluidity with this latter stream of research. If taken to its final conclusion, then the idea of promoting organizational fluidity would imply losing the very essence of organizing. Nevertheless, achieving organizational flexibility remains imperative in increasingly complex and volatile environments. To deal with this dilemma, an alternative approach is needed. We suggest a conceptualization of this dilemma that emphasizes the complementary dynamics between the two perspectives. We therefore provide an alternative conception that favors the idea of balancing countervailing processes in organizations with respect to the conflicting demands of organizational efficiency and fluidity.

Polyreactivity increases the apparent affinity of anti-HIV antibodies by heteroligation

Abstract: During immune responses, antibodies are selected for their ability to bind to foreign antigens with high affinity, in part by their ability to undergo homotypic bivalent binding. However, this type of binding is not always possible. For example, the small number of gp140 glycoprotein spikes displayed on the surface of the human immunodeficiency virus (HIV) disfavours homotypic bivalent antibody binding. Here we show that during the human antibody response to HIV, somatic mutations that increase antibody affinity also increase breadth and neutralizing potency. Surprisingly, the responding naive and memory B cells produce polyreactive antibodies, which are capable of bivalent heteroligation between one high-affinity anti-HIV-gp140 combining site and a second low-affinity site on another molecular structure on HIV. Although cross-reactivity to self-antigens or polyreactivity is strongly selected against during B-cell development, it is a common serologic feature of certain infections in humans, including HIV, Epstein-Barr virus and hepatitis C virus. Seventy-five per cent of the 134 monoclonal anti-HIV-gp140 antibodies cloned from six patients with high titres of neutralizing antibodies are polyreactive. Despite the low affinity of the polyreactive combining site, heteroligation demonstrably increases the apparent affinity of polyreactive antibodies to HIV.

Multiple stressors in coupled river–floodplain ecosystems

Abstract: SUMMARY 1. Riverine floodplains are highly complex, dynamic and diverse ecosystems. At the same time they are among the world’s most threatened ecosystems because of the pervasiveness of dams, levees and other factors such as rapid spreading of non-native species. Hence, floodplains are ideal systems to study ecological impacts of multiple stressors at the local, regional and catchment scale. 2. Concepts such as the subsidy-stress hypothesis and the stress-induced community tolerance concept have been formulated to study the effect of stressors on aquatic and terrestrial ecosystems, as well as on their functional linkages. 3. Riverine floodplains are pulsed ecosystems with distinct flow, sediment, resource and thermal pulses – thereby creating distinct ‘windows of ecological opportunity’. Human modifications that truncate or amplify theses pulses will have cascading effects on river– floodplain interactions by shifting the thresholds of connectivity, resilience or resistance – causing drastic regime shifts. 4. Most aquatic insects and pond-breeding amphibians have complex life cycles with aquatic and terrestrial stages. They are exposed to different stressors in their aquatic and terrestrial realm. Because most life history functions of aquatic insects are restricted to a short terrestrial period, we need to fully integrate the ‘airscape’ into the future management of river–floodplain ecosystems. 5. Riverine floodplains integrate and accumulate multiple stressors at the catchment level, as reflected by distinct catchment fingerprints. Based on the European Catchment Data Base we provide spatially explicit information on multiple stressors; a key prerequisite for setting priorities in conservation and management planning. 6. Thematic implications: the management of stressed river and floodplain ecosystems is a major challenge for the near future and water managers worldwide. Management approaches need to be adaptive and embedded within a catchment-wide concept to cope with upcoming pressures originating from global change.

Intrinsic and Extrinsic Reading Motivation as Predictors of Reading Literacy: A Longitudinal Study.

Abstract: The purpose in this study was to examine the longitudinal relationships of intrinsic and extrinsic motivation with reading literacy development. In particular, the authors (a) investigated reading amount as mediator between motivation and reading literacy and (b) probed for bidirectional relationships between reading motivation and reading literacy, controlling for previous reading literacy. A total of 740 students participated in a longitudinal assessment starting in Grade 3, with further points of measurement in Grades 4 and 6. Structural equation models with latent variables showed that the relationship between intrinsic reading motivation and later reading literacy was mediated by reading amount but not when previous reading literacy was included in the model. A bidirectional relationship was found between extrinsic reading motivation and reading literacy: Grade 3 reading literacy negatively predicted extrinsic reading motivation in Grade 4, which in turn negatively predicted reading literacy in Grade 6. Implications for research and practice are discussed.

Gluconeogenesis in dairy cows: the secret of making sweet milk from sour dough.

Abstract: Gluconeogenesis is a crucial process to support glucose homeostasis when nutritional supply with glucose is insufficient. Because ingested carbohydrates are efficiently fermented to short-chain fatty acids in the rumen, ruminants are required to meet the largest part of their glucose demand by de novo genesis after weaning. The qualitative difference to nonruminant species is that propionate originating from ruminal metabolism is the major substrate for gluconeogenesis. Disposal of propionate into gluconeogenesis via propionyl-CoA carboxylase, methylmalonyl-CoA mutase, and the cytosolic form of phosphoenolpyruvate carboxykinase (PEPCK) has a high metabolic priority and continues even if glucose is exogenously supplied. Gluconeogenesis is regulated at the transcriptional and several posttranscriptional levels and is under hormonal control (primarily insulin, glucagon, and growth hormone). Transcriptional regulation is relevant for regulating precursor entry into gluconeogenesis (propionate, alanine and other amino acids, lactate, and glycerol). Promoters of the bovine pyruvate carboxylase (PC) and PEPCK genes are directly controlled by metabolic products. The final steps decisive for glucose release (fructose 1,6-bisphosphatase and glucose 6-phosphatase) appear to be highly dependent on posttranscriptional regulation according to actual glucose status. Glucogenic precursor entry, together with hepatic glycogen dynamics, is mostly sufficient to meet the needs for hepatic glucose output except in high-producing dairy cows during the transition from the dry period to peak lactation. Lactating cows adapt to the increased glucose requirement for lactose production by mobilization of endogenous glucogenic substrates and increased hepatic PC expression. If these adaptations fail, lipid metabolism may be altered leading to fatty liver and ketosis. Increasing feed intake and provision of glucogenic precursors from the diet are important to ameliorate these disturbances. An improved understanding of the complex mechanisms underlying gluconeogenesis may further improve our options to enhance the postpartum health status of dairy cows.

Comparative and International Corporate Governance

Abstract: In this article, we examine the state of the art in comparative and international corporate governance by identifying the key research questions, main concepts, and paradigms of explanations of cross-country diversity in corporate governance. First, we discuss the multiple definitions of corporate governance across disciplines and explore how this multi-dimensional nature of corporate governance posses challenges when making cross-national comparisons. Second, we review existing comparative research on corporate governance and highlight some of the main characteristics of comparative analysis. Third, we analyze how comparative corporate governance has been understood from four different scholarly perspectives: economics and management, culture and sociology, legal, and political paradigms. We conclude from this third section that future research should make an effort to

Cyberbullying: Labels, Behaviours and Definition in Three European Countries

Abstract: This study aims to examine students' perception of the term used to label cyberbullying, the perception of different forms and behaviours (written, verbal, visual, exclusion and impersonation) and the perception of the criteria used for its definition (imbalance of power, intention, repetition, anonymity and publicity) in three different European countries: Italy, Spain and Germany. Seventy adolescents took part in nine focus groups, using the same interview guide across countries. Thematic analysis focused on three main themes related to: (1) the term used to label cyberbullying, (2) the different behaviours representing cyberbullying, (3) the three traditional criteria of intentionality, imbalance of power and repetition and the two new criteria of anonymity and publicity. Results showed that the best word to label cyberbullying is 'cybermobbing' (in Germany), 'virtual' or 'cyber-bullying' (in Italy), and 'harassment' or 'harassment via Internet or mobile phone' (in Spain). Impersonation cannot be considered wholly as cyberbullying behaviour. In order to define a cyberbullying act, adolescents need to know whether the action was done intentionally to harm the victim, the effect on the victim and the repetition of the action (this latter criterion evaluated simultaneously with the publicity). Information about the anonymity and publicity contributes to better understand the nature and the severity of the act, the potential effects on the victim and the intentionality.

Rezension zu: Aglaja Przyborski, Monika Wohlrab-Sahr: Qualitative Sozialforschung. Ein Arbeitsbuch. 2., korr. Auflage. München: Oldenbourg Wissenschaftsverlag 2009.

Abstract: Dieses Einstiegswerk zur qualitativen Sozialforschung konzentriert sich auf die methodischen Grundzuge verschiedener Ansatze der interpretativen Sozialforschung. Es vermittelt eine sehr gute Grundlage fur die Anwendung der rekonstruktiven Methoden in Lehre und Forschung, da es den gesamten Forschungsprozess – die Entwicklung der Fragestellung, den Zugang zum Untersuchungsfeld, die Erhebung des empirischen Materials und die Auswertungsmoglichkeiten – begleitet. Die Autorinnen zeigen, wie in qualitativer Forschung empirisches Material durch systematische Vergleiche interpretiert wird und so begrundete Generalisierungen und Theorien entwickelt werden konnen.

A NusE:NusG Complex Links Transcription and Translation

Abstract: Bacterial NusG is a highly conserved transcription factor that is required for most Rho activity in vivo. We show by nuclear magnetic resonance spectroscopy that Escherichia coli NusG carboxyl-terminal domain forms a complex alternatively with Rho or with transcription factor NusE, a protein identical to 30S ribosomal protein S10. Because NusG amino-terminal domain contacts RNA polymerase and the NusG carboxy-terminal domain interaction site of NusE is accessible in the ribosomal 30S subunit, NusG may act as a link between transcription and translation. Uncoupling of transcription and translation at the ends of bacterial operons enables transcription termination by Rho factor, and competition between ribosomal NusE and Rho for NusG helps to explain why Rho cannot terminate translated transcripts.

Invertebrate neurophylogeny: suggested terms and definitions for a neuroanatomical glossary

Abstract: Invertebrate nervous systems are highly disparate between different taxa. This is reflected in the terminology used to describe them, which is very rich and often confusing. Even very general terms such as 'brain', 'nerve', and 'eye' have been used in various ways in the different animal groups, but no consensus on the exact meaning exists. This impedes our understanding of the architecture of the invertebrate nervous system in general and of evolutionary transformations of nervous system characters between different taxa. We provide a glossary of invertebrate neuroanatomical terms with a precise and consistent terminology, taxon-independent and free of homology assumptions. This terminology is intended to form a basis for new morphological descriptions. A total of 47 terms are defined. Each entry consists of a definition, discouraged terms, and a background/comment section. The use of our revised neuroanatomical terminology in any new descriptions of the anatomy of invertebrate nervous systems will improve the comparability of this organ system and its substructures between the various taxa, and finally even lead to better and more robust homology hypotheses.