Low energy neutron propagation in MCNPX and GEANT4

Simulations of neutron background from rock for underground experiments are presented. Neutron propagation through two types of rock, lead and hydrocarbon material is discussed. The results show a reasonably good agreement between GEANT4, MCNPX and GEANT3 in transporting low-energy neutrons.Comment: 9 Figure

Demographic and health profiles of people with severe mental illness in general practice in Australia: a cross-sectional study

Background. People with severe mental illness have a higher rate of premature death than the general population, largely due to primary care preventable diseases. There has been little research on the health profile of this population attending Australian general practices. Methods. In this nationwide cross-sectional study, MedicineInsight data for adult patients regularly attending general practices in 2018 were analysed to estimate the prevalence of schizophrenia or bipolar disorders (SBD) and investigate the health profile of people with SBD compared with other patients. Multilevel models clustered by practice (n = 565) and patient, and practice characteristics were created. Results. The prevalence of recorded SBD was 1.91% (95% CI = 1.88%–1.94%) among the 618 849 patients included. Patients with recorded SBD were more likely than other patients to have records of health risk factors, particularly smoking (aOR = 3.8, 95% CI = 3.6–3.9) and substance use (aOR = 5.9, 95% CI = 5.6–6.3), and higher probabilities of comorbidities including cardiovascular diseases (aOR = 1.3, 95% CI = 1.2–1.4), cancer (aOR = 1.1, 95% CI = 1.0–1.2), diabetes mellitus type 2 (aOR = 2.2, 95% CI = 2.0–2.3), chronic kidney diseases (aOR = 1.7, 95% CI = 1.5–2.0), chronic liver diseases (aOR = 3.3, 95% CI = 2.6–4.0) and chronic respiratory diseases (aOR = 1.7, 95% CI = 1.7–1.8). Conclusions. The higher prevalence of health risk factors and comorbidities among patients with recorded SBD underscores the need for proactive health risk monitoring and preventive care to address this health inequity

What's in a name; Genetic structure in Solanum section Petota studied using population-genetic tools

Background - The taxonomy and systematic relationships among species of Solanum section Petota are complicated and the section seems overclassified. Many of the presumed (sub)species from South America are very similar and they are able to exchange genetic material. We applied a population genetic approach to evaluate support for subgroups within this material, using AFLP data. Our approach is based on the following assumptions: (i) accessions that may exchange genetic material can be analyzed as if they are part of one gene pool, and (ii) genetic differentiation among species is expected to be higher than within species. Results - A dataset of 566 South-American accessions (encompassing 89 species and subspecies) was analyzed in two steps. First, with the program STRUCTURE 2.2 in an 'unsupervised' procedure, individual accessions were assigned to inferred clusters based on genetic similarity. The results showed that the South American members of section Petota could be arranged in 16 clusters of various size and composition. Next, the accessions within the clusters were grouped by maximizing the partitioning of genetic diversity among subgroups (i.e., maximizing Fst values) for all available individuals of the accessions (2767 genotypes). This two-step approach produced an optimal partitioning into 44 groups. Some of the species clustered as genetically distinct groups, either on their own, or combined with one or more other species. However, accessions of other species were distributed over more than one cluster, and did not form genetically distinct units. Conclusions - We could not find any support for 43 species (almost half of our dataset). For 28 species some level of support could be found varying from good to weak. For 18 species no conclusions could be drawn as the number of accessions included in our dataset was too low. These molecular data should be combined with data from morphological surveys, with geographical distribution data, and with information from crossing experiments to identify natural units at the species level. However, the data do indicate which taxa or combinations of taxa are clearly supported by a distinct set of molecular marker data, leaving other taxa unsupported. Therefore, the approach taken provides a general method to evaluate the taxonomic system in any species complex for which molecular data are available

Status and preliminary results of the ANAIS experiment at Canfranc

ANAIS (Annual Modulation with NaI's) is an experiment planned to investigate seasonal modulation effects in the signal of galactic WIMPs using up to 107 kg of NaI(Tl) in the Canfranc Underground Laboratory (Spain). A prototype using one single crystal (10.7 kg) is being developed before the installation of the complete experiment; the first results presented here show an average background level of 1.2 counts/(keV kg day) from threshold (Ethr~4 keV) up to 10 keV.Comment: 3 pages, 2 figures, talk delivered at the 7th International Workshop on Topics in Astroparticle and Underground Physics (TAUP 2001), September 2001, Laboratori Nazionali del Gran Sasso, Italy (to appear in the Conference Proceedings, Nucl. Phys. B (Proc. Suppl.)

Search for an annual modulation of dark-matter signals with a germanium spectrometer at the Sierra Grande Laboratory

Data collected during three years with a germanium spectrometer at the Sierra Grande underground laboratory have been analyzed for distinctive features of annual modulation of the signal induced by WIMP dark matter candidates. The main motivation for this analysis was the recent suggestion by the DAMA/NaI Collaboration that a yearly modulation signal could not be rejected at the 90% confidence level when analyzing data obtained with a high-mass low-background scintillator detector. We performed two different analyses of the data: First, the statistical distribution of modulation-significance variables (expected from an experiment running under the conditions of Sierra Grande) was compared with the same variables obtained from the data. Second, the data were analyzed in energy bins as an independent check of the first result and to allow for the possibility of a crossover in the expected signal. In both cases no statistically significant deviation from the null result was found, which could support the hypothesis that the data contain a modulated component. A plot is also presented to enable the comparison of these results to those of the DAMA collaboration.Comment: New version accepted by Astroparticle Physics. Changes suggested by the referee about the theoretical prediction of rates are included. Conclusions remain unaffected. 14 pages, LaTeX, 7 figures. Uses epsfig macr

Molecular markers for genebank management

In the last decade, the use of DNA markers for the study of crop genetic diversity has become routine, and has revolutionized biology. Increasingly, techniques are being developed to more precisely, quickly and cheaply assess genetic variation. These techniques have changed the standard equipment of many labs, and most germplasm scientists are expected to be trained in DNA data generation and interpretation. The rapid growth of new techniques has stimulated this update of IPGRI's Technical Bulletin No. 2, ”Molecular tools in plant genetic resources conservation: a guide to the technologies” (Karp et al. 1997b). Our goal is to update DNA techniques from this publication, to show examples of their applications, and to guide genebank researchers towards ways to maximize their use. This bulletin reviews basic qualities of molecular markers, their characteristics, the advantages and disadvantages of their applications, and analytical techniques, and provides some examples of their use.There is no single molecular approach for many of the problems facing genebank managers, and many techniques complement each other. However, some techniques are clearly more appropriate than others for some specific applications. In an ideal situation, the most appropriate marker(s) can be chosen irrespective of time or funding constraints, but in other cases the choice of marker(s) will depend on constraints of equipment or funds. The purpose of this publication is to explain the characteristics of different markers and guide to their use through a number of real examples that represent well informed choices. What is most important is to choose a marker that can appropriately address well-defined questions through good experimental design, ideally leading to peer-reviewed scientific publications. Experimental design has many definitions depending on the type of question being asked and on the field of science addressed. We use the term here in a very general way to cover all aspects of planning an experiment, including a clear definition of the question being addressed; knowledge of prior studies addressing the question; proper choice of molecular markers and of data used to address the question; knowledge of the characteristics, strengths and weaknesses of the data; sources of unexpected variation in the data; how much data are needed; proper methods to analyze the data; and limits to conclusions you can make from the results. One of the most important considerations before beginning any experiment is to address proper experimental design. Improper experimental design can make the work inconclusive, misleading, insignificant, and most likely unpublishable. Similarly, improvements in experimental design can change an uninspired study to a highly significant one with little to no increase in time and funds. Poor experimental design can waste significant resources and damage the reputation and impact of your genebank. It is beyond the scope of any publication to outline all possible pitfalls that can lead to poorly designed experiments, analyses or conclusions, and different considerations of proper experimental design need to be made in particular fields. This technical bulletin outlines some basic considerations regarding molecular marker types and analyses to lead the reader. There is no substitute, however, for basic knowledge of the biological questions being addressed, knowledge of the taxonomic group under consideration and a thorough literature review to ensure that similar work has not been done before. If limitations of any type hinder genebank and germplasm managers with regards to these factors, collaboration or consultation with experts is well worth the effort. Excellent reviews of methodology and data interpretation are presented in Weising et al. (1995), Hillis et al. (1996), Staub et al. (1996), Hillis (1997), Karp et al. (1997a,b) and Avise (2004). Hamrick and Godt (1997) present a review of isozyme data; Doebley (1992), Clegg (1993b) and Spooner and Lara-Cabrera (2001) present a review of molecular data for plant genetic resources and crop evolution; Bruford and Wayne (1993), Wang et al. (1994), Gupta et al. (1996), Powell et al. (1996a) and Weising et al. (1998) of microsatellite data; Wolfe and Liston (1998) on Polymerase Chain Reaction (PCR) related data. Schlötterer (2004) reviews the history and relative utility of different molecular marker types. Sytsma and Hahn (1997) present reviews of molecular studies in crop and non-crop plants. Some information from Spooner and Lara-Cabrera (2001) for crop diversity studies was used and updated; Spooner et al. (2003) was used for taxonomy studies. An overview of the main marker techniques and their comparative qualities is presented in the section titled, ”Overview of molecular technologies”. Applications of molecular techniques in genebank management and crop breeding are the subject of the following sections. The section titled, ”Future challenges” focuses on the current developments in molecular marker applications and future challenges that could result from these developments. Elements of experimental design are discussed throughout and some basic aspects of data analysis are discussed in ”Genebank management”

Assessing the Ability of Simulated Laboratory Scenes to Predict the Image Quality Performance of HDR Captures (and Rendering) of Exterior Scenes Using Mobile Phone Cameras

With the advent of computational photography, most cellphones include High Dynamic Range (HDR) modes or “apps” that capture and render high contrast scenes in-camera using techniques such as multiple exposures and subsequent “addition” of those exposures to render a properly exposed image. The results from different cameras vary. Testing the image quality of different cameras involves field-testing under dynamic lighting conditions that may involve moving objects. Such testing often becomes a cumbersome and time-consuming task. It would be more efficient to conduct such testing in a controlled, laboratory environment. This study investigates the feasibility of such testing. Natural exterior scenes, at day and night, some of which include “motion”, were captured with a range of cellphone cameras using their native HDR modes. The luminance ratios of these scenes were accurately measured using various spectro-radiometers and luminance meters. Artificial scenes, which include characteristics of the natural exterior scenes and have similar luminance ratios, were created in a laboratory environment. These simulated scenes were captured using the same modes as the natural exterior scenes. A subjective image quality evaluation was conducted using some 20 observers to establish an observer preference scale separately for each scene. For each natural exterior scene, the correlation coefficients between its preference scale and the preference scale obtained for each laboratory scene were calculated, and the laboratory scene with the highest correlation was identified. It was determined that while it was difficult to accurately quantify the actual dynamic range of a natural exterior scene, especially at night, we could still simulate the luminance ratios of a wide range of natural exterior HDR scenes, from 266:1 to 15120:1, within a laboratory environment. Preliminary results of the subjective study indicated that reasonably good correlation (0.8 or higher on average) was obtained between the natural exterior and laboratory simulated scenes. However, such correlations were determined to be specific to the type of scene studied. The scope of this study needs to be narrowed. Another consideration, how moving objects in the scene would affect the results, needs further investigation

Levels of Intra-specific AFLP Diversity in Tuber-Bearing Potato Species with Different Breeding Systems and Ploidy Levels

DNA-based marker analysis of plant genebank material has become a useful tool in the evaluation of levels of genetic diversity and for the informed use and maintenance of germplasm. In this study, we quantify levels of amplified fragment length polymorphism (AFLP) in representative accessions of wild and cultivated potato species of differing geographic origin, ploidy, and breeding system. We generated 449 polymorphic AFLP fragments in 619 plants, representing multiple plants (16–23) from 17 accessions of 14 potato taxa as well as single plants sampled from available accessions (from 3 to 56) of the same 14 taxa. Intra-accession diversities were compared to those of a synthetic ‘taxon-wide’ population comprising a single individual from a variable number of available accessions of each sampled taxon. Results confirm the expected considerably lower levels of polymorphism within accessions of self-compatible as compared to self-incompatible taxa. We observed broadly similar levels of ‘taxon-wide’ polymorphism among self-compatible and self-incompatible species, with self-compatible taxa showing only slightly lower rates of polymorphism. The most diverse accessions were the two cultivated potato accessions examined, the least diverse being the Mexican allohexaploids Solanum demissum and S. iopetalum. Generally allopolyploid self-compatible accessions exhibited lower levels of diversity. Some purported self-incompatible accessions showed relatively low levels of marker diversity, similar to the more diverse self-compatible material surveyed. Our data indicate that for self-compatible species a single plant is highly representative of a genebank accession. The situation for self-incompatible taxa is less clear, and sampling strategies used will depend on the type of investigation. These results have important implications for those seeking novel trait variation (e.g., disease resistance) in gene banks as well as for the selection of individuals for genomics studies. We also show that AFLPs, despite having been largely replaced by other marker types, is highly suitable for the evaluation of within and between accession diversity in genebanks

Event categories in the EDELWEISS WIMP search experiment

Four categories of events have been identified in the EDELWEISS-I dark matter experiment using germanium cryogenic detectors measuring simultaneously charge and heat signals. These categories of events are interpreted as electron and nuclear interactions occurring in the volume of the detector, and electron and nuclear interactions occurring close to the surface of the detectors(10-20 mu-m of the surface). We discuss the hypothesis that low energy surface nuclear recoils,which seem to have been unnoticed by previous WIMP searches, may provide an interpretation of the anomalous events recorded by the UKDMC and Saclay NaI experiments. The present analysis points to the necessity of taking into account surface nuclear and electron recoil interactions for a reliable estimate of background rejection factors.Comment: 11 pages, submitted to Phys. Lett.

SICANE: a Detector Array for the Measurement of Nuclear Recoil Quenching Factors using Monoenergetic Neutron Beam

SICANE is a neutron scattering multidetector facility for the determination of the quenching factor (ratio of the response to nuclear recoils and to electrons) of cryogenic detectors used in direct WIMP searches. Well collimated monoenergetic neutron beams are obtained with inverse (p,n) reactions. The facility is described, and results obtained for the quenching factors of scintillation in NaI(Tl) and of heat and ionization in Ge are presented.Comment: 30 pages, Latex, 11 figures. Submitted to NIM