Chronic Radiation Exposure at Chernobyl Shows No Effect on Genetic Diversity in the Freshwater Crustacean, Asellus aquaticus Thirty Years On

International audienceAnalysis of genetic diversity represents a fundamental component of ecological risk assessments in contaminated environments. Many studies have assessed the genetic implications of chronic radiation exposure at Chernobyl, generally recording an elevated genetic diversity and mutation rate in rodents, plants and birds inhabiting contaminated areas. Only limited studies have considered genetic diversity in aquatic biota at Chernobyl, despite the large number of freshwater systems where elevated dose rates will persist for many years. Consequently the present study aimed to assess the effects of chronic radiation exposure on genetic diversity in the freshwater crustacean, Asellus aquaticus, using a genome-wide SNP approach (Genotyping-by-sequencing). It was hypothesised that genetic diversity in A. aquaticus would be positively correlated with dose rate. A. aquaticus was collected from six lakes in Belarus and the Ukraine ranging in dose rate from 0.064 to 27.1 µGy/hr. Genotyping-by-sequencing analysis was performed on 74 individuals. A significant relationship between geographical distance and genetic differentiation confirmed the Isolation-by-Distance model. Conversely, no significant relationship between dose rate and genetic differentiation suggested no effect of the contamination gradient on genetic differentiation between populations. No significant relationship between five measures of genetic diversity and dose rate were recorded, suggesting that radiation exposure has not significantly influenced genetic diversity in A. aquaticus at Chernobyl. This is the first study to adopt a genome-wide SNP approach to assess the impacts of environmental radiation exposure on biota. These findings are fundamental to understanding the long-term success of aquatic populations in contaminated environments at Chernobyl and Fukushima

Understanding the information needs of public health practitioners: A literature review to inform design of an interactive digital knowledge management system

AbstractThe need for rapid access to information to support critical decisions in public health cannot be disputed; however, development of such systems requires an understanding of the actual information needs of public health professionals. This paper reports the results of a literature review focused on the information needs of public health professionals. The authors reviewed the public health literature to answer the following questions: (1) What are the information needs of public health professionals? (2) In what ways are those needs being met? (3) What are the barriers to meeting those needs? (4) What is the role of the Internet in meeting information needs? The review was undertaken in order to develop system requirements to inform the design and development of an interactive digital knowledge management system. The goal of the system is to support the collection, management, and retrieval of public health documents, data, learning objects, and tools.Method:The search method extended beyond traditional information resources, such as bibliographic databases, tables of contents (TOC), and bibliographies, to include information resources public health practitioners routinely use or have need to use—for example, grey literature, government reports, Internet-based publications, and meeting abstracts.Results:Although few formal studies of information needs and information-seeking behaviors of public health professionals have been reported, the literature consistently indicated a critical need for comprehensive, coordinated, and accessible information to meet the needs of the public health workforce. Major barriers to information access include time, resource reliability, trustworthiness/credibility of information, and “information overload”.Conclusions:Utilizing a novel search method that included the diversity of information resources public health practitioners use, has produced a richer and more useful picture of the information needs of the public health workforce than other literature reviews. There is a critical need for public health digital knowledge management systems designed to reflect the diversity of public health activities, to enable human communications, and to provide multiple access points to critical information resources. Public health librarians and other information specialists can serve a significant role in helping public health professionals meet their information needs through the development of evidence-based decision support systems, human-mediated expert searching and training in the use information retrieval systems

Hardware Design and Implementation of a MAVLink Interface for an FPGA-Based Autonomous UAV Flight Control System

Abstract This paper details the initial design and planning of a Field Programmable Gate Array (FPGA) implemented control system that will enable a path planner to interact with a MAVLink based flight computer. The design is aimed at small Unmanned Aircraft Vehicles (UAV) under autonomous operation which are typically subject to constraints arising from limited on-board processing capabilities, power and size. An FPGA implementation for the design is chosen for its potential to address such limitations through low power and high speed inhardware computation. The MAVLink protocol offers a low bandwidth interface for the FPGA implemented path planner to communicate with an on-board flight computer. A control system plan is presented that is capable of accepting a string of GPS waypoints generated on-board from a previously developed in-hardware Genetic Algorithm (GA) path planner and feeding them to the open source PX4 autopilot, while simultaneously responding with flight status information

Small unmanned aerial model accuracy for photogrammetrical fluvial bathymetric survey

Fluvial systems offer a challenging and varied environment for topographic survey, displaying a rapidly varying morphology, vegetation assemblage and degree of submergence. Traditionally theodolite or GPS based systems have been used to capture cross-section and breakline based topographic data which has subsequently been interpolated. Advances in survey technology has resulted in an improved ability to capture larger volumes of information with infrared terrestrial and aerial LiDAR systems capturing high density (<0.02 m) point data across terrestrial surfaces. The rise of Structure from Motion (SfM) photogrammetry, coupled with small unmanned aerial vehicles (sUAV), has potential to record elevation data at reach scale sub decimetre density. The approach has the additional advantage over LiDAR of seeing through clear water to capture bed detail, whilst also generating ortho-rectified photographic mosaics of the survey reach. However, data accuracy has yet to be comprehensively assessed. Here we present a survey protocol for sUAV deployment and provide a reach scale comparison between a theodolite and SfM sUAV survey on the River Sprint, Kendal, the River Ehen at Egremont, England and the Afon Elwy, at Llanfair Talhaiarn, Wales. Comparative analysis between theodolite survey and SfM suggest similar accuracy and precision across terrestrial surfaces with error lowest over solid surfaces, increasing with vegetation complexity. Submerged SfM data, captured bed levels generally to within ±0.25 m with only a weak relationship recorded between error and flow depth. Significantly, associated error when linked to channel D50 highlights the ability of unmanned aerial vehicles to capture accurate fluvial data across a range of river biotopes and depths to 2.4 m

The p68 and p72 DEAD box RNA helicases interact with HDAC1 and repress transcription in a promoter-specific manner

BACKGROUND: p68 (Ddx5) and p72 (Ddx17) are highly related members of the DEAD box family and are established RNA helicases. They have been implicated in growth regulation and have been shown to be involved in both pre-mRNA and pre-rRNA processing. More recently, however, these proteins have been reported to act as transcriptional co-activators for estrogen-receptor alpha (ERα). Furthermore these proteins were shown to interact with co-activators p300/CBP and the RNA polymerase II holoenzyme. Taken together these reports suggest a role for p68 and p72 in transcriptional activation. RESULTS: In this report we show that p68 and p72 can, in some contexts, act as transcriptional repressors. Targeting of p68 or p72 to constitutive promoters leads to repression of transcription; this repression is promoter-specific. Moreover both p68 and p72 associate with histone deacetylase 1 (HDAC1), a well-established transcriptional repression protein. CONCLUSIONS: It is therefore clear that p68 and p72 are important transcriptional regulators, functioning as co-activators and/or co-repressors depending on the context of the promoter and the transcriptional complex in which they exist

Method of manufacturing a light emitting, photovoltaic or other electronic apparatus and system

The present invention provides a method of manufacturing an electronic apparatus, such as a lighting device having light emitting diodes (LEDs) or a power generating device having photovoltaic diodes. The exemplary method includes depositing a first conductive medium within a plurality of channels of a base to form a plurality of first conductors; depositing within the plurality of channels a plurality of semiconductor substrate particles suspended in a carrier medium; forming an ohmic contact between each semiconductor substrate particle and a first conductor; converting the semiconductor substrate particles into a plurality of semiconductor diodes; depositing a second conductive medium to form a plurality of second conductors coupled to the plurality of semiconductor diodes; and depositing or attaching a plurality of lenses suspended in a first polymer over the plurality of diodes. In various embodiments, the depositing, forming, coupling and converting steps are performed by or through a printing process