407 research outputs found
Environmental occurrence of the Whipple's disease bacterium (Tropheryma whippelii).
Whipple's disease is a systemic disorder in which a gram-positive rod-shaped bacterium is constantly present in infected tissues. After numerous unsuccessful attempts to culture this bacterium, it was eventually characterized by 16S rRNA gene analysis to be a member of the actinomycetes. The name Tropheryma whippelii was proposed. Until now, the bacterium has only been found in infected human tissues, but there is no evidence for human-to-human transmission. Here we report the detection of DNA specific for the Whipple's disease bacterium in 25 of 38 wastewater samples from five different sewage treatment plants in the area of Heidelberg, Germany. These findings provide the first evidence that T. whippelii occurs in the environment, within a polymicrobial community. This is in accordance with the phylogenetic relationship of this bacterium as well as with known epidemiological aspects of Whipple's disease. Our data argue for an environmental source for infection with the Whipple's disease bacterium
Putting theory oriented evaluation into practice
Evaluations of gaming simulations and business games as teaching devices are typically end-state driven. This emphasis fails to detect how the simulation being evaluated does or does not bring about its desired consequences. This paper advances the use of a logic model approach which possesses a holistic perspective that aims at including all elements associated with the situation created by a game. The use of the logic model approach is illustrated as applied to Simgame, a board game created for secondary school level business education in six European Union countries
Watched over or over-watched? Open street CCTV in Australia
Most developed countries, Australia included, are witnessing increased government and public concerns about crime and security. Amid these anxieties, closed circuit television (CCTV) systems to monitor public spaces are increasingly being touted as a solution to problems of crime and disorder. The city of Perth established Australia’s first open street closed circuit television system in July 1991. Subsequently, there has been significant expansion. At the end of 2002 Australia had 33 “open street” CCTV schemes. Based on site inspections, extensive reviews of documentation and interviews with 22 Australian administrators, this article discusses issues relating to system implementation, management and accountability.We also suggest ways relevant authorities might ensure that current and future schemes are appropriately audited and evaluated. We argue that rigorous independent assessment of both the intended and unintended consequences of open street CCTV is essential to ensure this measure is not deployed inappropriately. Finally, this article suggests any potential crime prevention benefits must be carefully weighed against the potential of CCTV to exacerbate social division and exclusion
A preliminary fishery quality index for Portuguese streams
There is a need to quantify the multivariate quality of a recreational fishery at the site scale to
better communicate the relative quality among sites to the public and anglers. Borrowing on the general
approach of multimetric indices of biotic integrity (IBIs), we developed fishery quality indices (FQIs) from
species quality indices (SQIs) based on measures of fish abundance and size structure for northern and central
Portuguese streams. Our FQIs showed regional patterns indicating a range in fishery quality. Higher coldwater
FQI scores were mostly found in the northwestern (Minho and Lima), northeastern Douro, and northern Tagus
basins. Higher warmwater FQI scores occurred in the eastern Tagus basin. The species that contributed the
most to warmwater FQI scores were largemouth bass Micropterus salmoides, pumpkinseed Lepomis
gibbosus, the cyprinid Luciobarbus bocagei, chubs Squalius carolitertii and S. pyrenaicus, and nases
Pseudochondrostoma duriense and P. polylepis. The chubs, nases, and brown trout Salmo trutta contributed
the most to coldwater FQI scores. As expected, our indices were correlated with river size and with
disturbance at the catchment, segment, and site scales. Regression models for separate coldwater and
warmwater FQIs were stronger than those for the individual SQIs and for an all-site FQI. The correlation was
positive between the coldwater FQI and a coldwater IBI but negative between the warmwater FQI and
warmwater IBIs. The proposed FQIs offer a quantitative approach for assessing relative fishery quality among
sites and for making regional assessments given an appropriate study design. The component SQIs and SQI
metrics of the FQIs can be disassociated to determine the population and species characteristics most affected
by various environmental variables
Water quality is a poor predictor of recreational hotspots in England
Maintaining and improving water quality is key to the protection and restoration of aquatic ecosystems, which provide important benefits to society. In Europe, the Water Framework Directive (WFD) defines water quality based on a set of biological, hydro-morphological and chemical targets, and aims to reach good quality conditions in all river bodies by the year 2027. While recently it has been argued that achieving these goals will deliver and enhance ecosystem services, in particular recreational services, there is little empirical evidence demonstrating so. Here we test the hypothesis that good water quality is associated with increased utilization of recreational services, combining four surveys covering walking, boating, fishing and swimming visits, together with water quality data for all water bodies in eight River Basin Districts (RBDs) in England. We compared the percentage of visits in areas of good water quality to a set of null models accounting for population density, income, age distribution, travel distance, public access, and substitutability. We expect such association to be positive, at least for fishing (which relies on fish stocks) and swimming (with direct contact to water). We also test if these services have stronger association with water quality relative to boating and walking alongside rivers, canals or lakeshores. In only two of eight RBDs (Northumbria and Anglian) were both criteria met (positive association, strongest for fishing and swimming) when comparing to at least one of the null models. This conclusion is robust to variations in dataset size. Our study suggests that achieving the WFD water quality goals may not enhance recreational ecosystem services, and calls for further empirical research on the connection between water quality and ecosystem services
Support of students in primary schools: a comparative case study in a selective educational system
Journal of Curriculum Studies, 53(3), 279-29
Evolution and Survival on Eutherian Sex Chromosomes
Since the two eutherian sex chromosomes diverged from an ancestral autosomal pair, the X has remained relatively gene-rich, while the Y has lost most of its genes through the accumulation of deleterious mutations in nonrecombining regions. Presently, it is unclear what is distinctive about genes that remain on the Y chromosome, when the sex chromosomes acquired their unique evolutionary rates, and whether X-Y gene divergence paralleled that of paralogs located on autosomes. To tackle these questions, here we juxtaposed the evolution of X and Y homologous genes (gametologs) in eutherian mammals with their autosomal orthologs in marsupial and monotreme mammals. We discovered that genes on the X and Y acquired distinct evolutionary rates immediately following the suppression of recombination between the two sex chromosomes. The Y-linked genes evolved at higher rates, while the X-linked genes maintained the lower evolutionary rates of the ancestral autosomal genes. These distinct rates have been maintained throughout the evolution of X and Y. Specifically, in humans, most X gametologs and, curiously, also most Y gametologs evolved under stronger purifying selection than similarly aged autosomal paralogs. Finally, after evaluating the current experimental data from the literature, we concluded that unique mRNA/protein expression patterns and functions acquired by Y (versus X) gametologs likely contributed to their retention. Our results also suggest that either the boundary between sex chromosome strata 3 and 4 should be shifted or that stratum 3 should be divided into two strata
Erfolg in der Berufsbildung
Rund ein Drittel aller Berufslehrabschlüsse in der Schweiz entfallen auf die Berufslehre Kauffrau/Kaufmann. Studien belegen die Wichtigkeit des Ausbildungserfolgs für die unmittelbare berufliche Anschlusslösung und kumulativ für die weitere berufliche Laufb ahn. Die vorliegende Arbeit geht der Frage nach, welche Faktoren den Ausbildungserfolg in der dualen kaufmännischen Berufslehre, gemessen an der Abschlussnote, erklären. Mit den Daten von 320 Deutschschweizer kaufmännischen Berufslernenden werden, unter Berücksichtigung der Mehrebenenstruktur, Berechnungsmodelle entwickelt, welche eine Vielzahl von Faktoren auf der Mikro- und Mesoebene der Berufsausbildung auf ihre Vorhersagekraft des Ausbildungserfolgs prüfen. Die Ergebnisse zeigen, dass vor allem individuelle Faktoren der Lernenden, wie zum Beispiel Persönlichkeitsdimensionen, die Abschlussnoten erklären. Teils werden auch unterschiedliche Prädiktoren für die berufsfachschulische und die ausbildungsbetriebliche Berufslehrabschlussnote gefunden. So ist der Schulabschluss auf der Sekundarschule I für die berufsfachschulische, nicht aber für die ausbildungsbetriebliche Abschlussnote prädiktiv. Zudem werden unter gegenseitiger Kontrolle neben Faktoren der Person auch Faktoren der Berufsfachschule (Klassenzugehörigkeit) und des Ausbildungsbetriebs (z.B. Anzahl kaufmännische Lernende im Ausbildungsbetrieb) als prädiktiv für die Abschlussnoten festgestellt
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