Seasonal Plasticity in GABA\u3csup\u3eA\u3c/sup\u3e Signaling is Necessary for Restoring Phase Synchrony in the Master Circadian Clock Network

Annual changes in the environment threaten survival, and numerous biological processes in mammals adjust to this challenge via seasonal encoding by the suprachiasmatic nucleus (SCN). To tune behavior according to day length, SCN neurons display unified rhythms with synchronous phasing when days are short, but will divide into two sub-clusters when days are long. The transition between SCN states is critical for maintaining behavioral responses to seasonal change, but the mechanisms regulating this form of neuroplasticity remain unclear. Here we identify that a switch in chloride transport and GABAA signaling is critical for maintaining state plasticity in the SCN network. Further, we reveal that blocking excitatory GABAA signaling locks the SCN into its long day state. Collectively, these data demonstrate that plasticity in GABAA signaling dictates how clock neurons interact to maintain environmental encoding. Further, this work highlights factors that may influence susceptibility to seasonal disorders in humans

Testing in the incremental design and development of complex products

Testing is an important aspect of design and development which consumes significant time and resource in many companies. However, it has received less research attention than many other activities in product development, and especially, very few publications report empirical studies of engineering testing. Such studies are needed to establish the importance of testing and inform the development of pragmatic support methods. This paper combines insights from literature study with findings from three empirical studies of testing. The case studies concern incrementally developed complex products in the automotive domain. A description of testing practice as observed in these studies is provided, confirming that testing activities are used for multiple purposes depending on the context, and are intertwined with design from start to finish of the development process, not done after it as many models depict. Descriptive process models are developed to indicate some of the key insights, and opportunities for further research are suggested

High Concentrations of Pharmaceuticals in a Nigeria River Catchment

Pharmaceutical contamination of the environment is recognized as a global problem although most work has focused on Europe and North America to date and there remains a dearth of information for developing countries, including those in Africa. To address this data gap the occurrence of thirty‐seven pharmaceuticals belonging to nineteen therapeutic classes was monitored in surface water and effluents in Lagos State, Southwest Nigeria. Samples were collected quarterly between April 2017 and March 2018 from 22 sites, and 26 compounds were detected at least once, many in the microgram per litre range. Maximum concentrations for those compounds detected ranged from 75 to 129 µg L‐1 and even mean concentrations for thirteen compounds were in the order of µg L‐1. These values are amongst the highest ever measured globally. Sewage effluent was more important than drug manufacturing waste in polluting rivers although there are likely to be numerous unregulated sources of effluent being discharged to rivers which require further study, including urban waste collection areas and vacuum trucks which collect effluent. Seasonal trends in the data were complex with some compounds being found at higher concentrations in the dry season and, conversely, others being greater during the wet period, this variation potentially relating to the variety of pollution sources in the catchment. Pharmaceuticals are indispensable to human health although their usage and discharge into the aquatic environment may lead to ecological problems and antibiotic resistance. The data presented in this paper indicate that pharmaceutical pollution of freshwaters is a serious issue in Nigeria and management efforts are needed to improve this problem

Return and Volatility Spillovers of Asian Pacific Stock Markets’ Energy Indices

The aim of the study was to investigate the presence of volatility among the Energy Indices of Asia Pacific Stock Markets. To test the volatility among the daily returns of Energy Indices of Asia Pacific Stock Markets, the study selected five sample Asian Pacific stock markets’ Energy Indices on the basis of availability of data. The findings of descriptive statistics and the ADF Test revealed, that the daily returns of the sample energy indices of Asian Pacific stock markets were not normally distributed and achieved stationarity at level difference, over the research period. Hence the data may be used for additional analysis. The data were then analysed, by using the GARCH (1,1) model to assess the considerable volatility of daily returns of sample energy indices and the study, which revealed that during the study period, all of the sample energy indices were volatile

Processing DNA molecules as text

Polymerase Chain Reaction (PCR) is the DNA-equivalent of Gutenberg’s movable type printing, both allowing large-scale replication of a piece of text. De novo DNA synthesis is the DNA-equivalent of mechanical typesetting, both ease the setting of text for replication. What is the DNA-equivalent of the word processor? Biology labs engage daily in DNA processing—the creation of variations and combinations of existing DNA—using a plethora of manual labor-intensive methods such as site-directed mutagenesis, error-prone PCR, assembly PCR, overlap extension PCR, cleavage and ligation, homologous recombination, and others. So far no universal method for DNA processing has been proposed and, consequently, no engineering discipline that could eliminate this manual labor has emerged. Here we present a novel operation on DNA molecules, called Y, which joins two DNA fragments into one, and show that it provides a foundation for DNA processing as it can implement all basic text processing operations on DNA molecules including insert, delete, replace, cut and paste and copy and paste. In addition, complicated DNA processing tasks such as the creation of libraries of DNA variants, chimeras and extensions can be accomplished with DNA processing plans consisting of multiple Y operations, which can be executed automatically under computer control. The resulting DNA processing system, which incorporates our earlier work on recursive DNA composition and error correction, is the first demonstration of a unified approach to DNA synthesis, editing, and library construction

An epitaph to Section 28? Telling tales out of school about changes and challenges to discourses of sexuality

This is a postprint of an article whose final and definitive form has been published in the International Journal of Qualitative Studies in Education,© 2007 Copyright Taylor & Francis; International Journal of Qualitative Studies in Education, is available online at http://www.informaworld.comThis article seeks to develop an understanding of the professional and personal lives of LGBT teachers in relation to the discriminatory statute Section 28, which prohibited 'promotion' of 'the acceptability of homosexuality as a pretended family relationship' by local education authorities in the UK (except Northern Ireland). Interviews with a small sample of serving teachers are analysed using a feminist poststructuralist methodology to discover whether the removal of this legislation marks a shift in theorization, policy or practice. Findings are arranged to focus on the workings of official policy, on informal or unofficial classroom and staffroom practices, and on relations with a local community. Analysis and discussion reveal a complex matrix of constituents (space, relationships and other variables) only some of which respond to the (perhaps) superficial stimulus of legislative change. Such change goes only a small way to challenge a deeply embedded discourse of inequality, which may respond only to a more profound epistemological transformation

Highly reflective load-pull

This article presented a review of the most common load-pull approaches adopted in the measurement and characterization of large-periphery microwave transistor devices. Although the quarterwave transformer technique is simple and very cost-effective, it has serious limitations in terms of scalability, thereby necessitating a separate quarterwave transformer for each device and frequency. Furthermore, due to the limited bandwidth of the quarterwave transformer, its usage in harmonic load-pull applications is severely limited