515 research outputs found

    Comparison of the Flammability of Three Types of Fabrics Used in Girls' Sleepwear

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    Clothing, Textiles, and Merchandisin

    Characterization of Environmental Solids and Surfaces

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    The characterization of the solid phase is one of the first steps in the study of any of the myriad of environmental reactions that involve solids and solid-liquid interfaces. Environmental solids range from relatively pure and crystalline phases to heterogeneous and multiphasic particle aggregates whose characterization requires a combination of a number of analytical methods and methodologies. The first section of this paper gives a cross section of general strategies used in different departments at EAWAG for the characterization of field samples of both natural and anthropogenic origin. The morphological characterization and the determination of the chemical composition is described in respect to the properties of anthropogenic solids. As an example, the long-term behavior of incinerator bottom ash is discussed in a case study. A second section gives two examples of molecular level studies on environmental solids: application of Extended X-Ray Absorption Fine Structure (EXAFS) spectroscopy for the characterization of poorly crystallized manganese lake particles in the context of the genesis of lake sediments, and in situ Atomic Force Microscopy (AFM) and Fourier Transform Infrared (FTIR) studies on synthetic goethite particles during the oxidation of FeII and the reduction of CrVI

    Digital gene expression analysis of two life cycle stages of the human-infective parasite, Trypanosoma brucei gambiense reveals differentially expressed clusters of co-regulated genes

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    <p><b>Background</b></p> <p>The evolutionarily ancient parasite, Trypanosoma brucei, is unusual in that the majority of its genes are regulated post-transcriptionally, leading to the suggestion that transcript abundance of most genes does not vary significantly between different life cycle stages despite the fact that the parasite undergoes substantial cellular remodelling and metabolic changes throughout its complex life cycle. To investigate this in the clinically relevant sub-species, Trypanosoma brucei gambiense, which is the causative agent of the fatal human disease African sleeping sickness, we have compared the transcriptome of two different life cycle stages, the potentially human-infective bloodstream forms with the non-human-infective procyclic stage using digital gene expression (DGE) analysis.</p> <p><b>Results</b></p> <p>Over eleven million unique tags were generated, producing expression data for 7360 genes, covering 81% of the genes in the genome. Compared to microarray analysis of the related T. b. brucei parasite, approximately 10 times more genes with a 2.5-fold change in expression levels were detected. The transcriptome analysis revealed the existence of several differentially expressed gene clusters within the genome, indicating that contiguous genes, presumably from the same polycistronic unit, are co-regulated either at the level of transcription or transcript stability.</p> <p><b>Conclusions</b></p> <p>DGE analysis is extremely sensitive for detecting gene expression differences, revealing firstly that a far greater number of genes are stage-regulated than had previously been identified and secondly and more importantly, this analysis has revealed the existence of several differentially expressed clusters of genes present on what appears to be the same polycistronic units, a phenomenon which had not previously been observed in microarray studies. These differentially regulated clusters of genes are in addition to the previously identified RNA polymerase I polycistronic units of variant surface glycoproteins and procyclin expression sites, which encode the major surface proteins of the parasite. This raises a number of questions regarding the function and regulation of the gene clusters that clearly warrant further study.</p&gt

    Review: Assessment of completeness of reporting in intervention studies using livestock: an example from pain mitigation interventions in neonatal piglets

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    Accurate and complete reporting of study methods, results and interpretation are essential components for any scientific process, allowing end-users to evaluate the internal and external validity of a study. When animals are used in research, excellence in reporting is expected as a matter of continued ethical acceptability of animal use in the sciences. Our primary objective was to assess completeness of reporting for a series of studies relevant to mitigation of pain in neonatal piglets undergoing routine management procedures. Our second objective was to illustrate how authors can report the items in the Reporting guidElines For randomized controLled trials for livEstoCk and food safety (REFLECT) statement using examples from the animal welfare science literature. A total of 52 studies from 40 articles were evaluated using a modified REFLECT statement. No single study reported all REFLECT checklist items. Seven studies reported specific objectives with testable hypotheses. Six studies identified primary or secondary outcomes. Randomization and blinding were considered to be partially reported in 21 and 18 studies, respectively. No studies reported the rationale for sample sizes. Several studies failed to report key design features such as units for measurement, means, standard deviations, standard errors for continuous outcomes or comparative characteristics for categorical outcomes expressed as either rates or proportions. In the discipline of animal welfare science, authors, reviewers and editors are encouraged to use available reporting guidelines to ensure that scientific methods and results are adequately described and free of misrepresentations and inaccuracies. Complete and accurate reporting increases the ability to apply the results of studies to the decision-making process and prevent wastage of financial and animal resources

    Community perspectives on the benefits and risks of technologically enhanced communicable disease surveillance systems: A report on four community juries

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    Background Outbreaks of infectious disease cause serious and costly health and social problems. Two new technologies – pathogen whole genome sequencing (WGS) and Big Data analytics – promise to improve our capacity to detect and control outbreaks earlier, saving lives and resources. However, routinely using these technologies to capture more detailed and specific personal information could be perceived as intrusive and a threat to privacy. Method Four community juries were convened in two demographically different Sydney municipalities and two regional cities in New South Wales, Australia (western Sydney, Wollongong, Tamworth, eastern Sydney) to elicit the views of well-informed community members on the acceptability and legitimacy of: making pathogen WGS and linked administrative data available for public health research using this information in concert with data linkage and machine learning to enhance communicable disease surveillance systems Fifty participants of diverse backgrounds, mixed genders and ages were recruited by random-digit-dialling and topic-blinded social-media advertising. Each jury was presented with balanced factual evidence supporting different expert perspectives on the potential benefits and costs of technologically enhanced public health research and communicable disease surveillance and given the opportunity to question experts. Results Almost all jurors supported data linkage and WGS on routinely collected patient isolates for the purposes of public health research, provided standard de-identification practices were applied. However, allowing this information to be operationalised as a syndromic surveillance system was highly contentious with three juries voting in favour, and one against by narrow margins. For those in favour, support depended on several conditions related to system oversight and security being met. Those against were concerned about loss of privacy and did not trust Australian governments to run secure and effective systems. Conclusions Participants across all four events strongly supported the introduction of data linkage and pathogenomics to public health research under current research governance structures. Combining pathogen WGS with event-based data surveillance systems, however, is likely to be controversial because of a lack of public trust, even when the potential public health benefits are clear. Any suggestion of private sector involvement or commercialisation of WGS or surveillance data was unanimously rejected

    The development of bone char-based filters for the removal of flouride from drinking water

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    Millions of people rely on drinking water that contains excess fluoride. Only few fluoride removal techniques have been implemented on a wider scale in low and middle income countries. One of these methods, bone char filtration, is highly efficient. However, its lifespan is rather limited. This paper presents first laboratory results and field testing of a new fluoride removal technology, based on a combination of bone char and calcium-phosphate pellets. These chemicals are slowly released to the water for fluoride precipitation. Although this method, commonly referred to as contact precipitation is known, the development of such pellets is new. Fixed-bed laboratory experiments show that this mixture of materials can increase filter uptake capacity by a factor of 3 and more. However, to reduce the phosphate concentration in the treated water, the design of full-scale community filters for field testing has to be slightly modified

    Genetic Association of Multiple Sclerosis with the Marker rs391745 near the Endogenous Retroviral Locus HERV-Fc1: Analysis of Disease Subtypes

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    We have previously described the occurrence of multiple sclerosis (MS) to be associated with human endogenous retroviruses, specifically the X-linked viral locus HERV-Fc1. The aim of this study was to investigate a possible association of the HERV-Fc1 locus with subtypes of MS. MS patients are generally subdivided into three categories: Remitting/Relapsing and Secondary Progressive, which together constitute Bout Onset MS, and Primary Progressive. In this study of 1181 MS patients and 1886 controls we found that Bout Onset MS was associated with the C-allele of the marker rs391745 near the HERV-Fc1 locus (p = 0.003), while primary progressive disease was not. The ability to see genetic differences between subtypes of MS near this gene speaks for the involvement of the virus HERV-Fc1 locus in modifying the disease course of MS

    Probing the Nature of the G1 Clump Stellar Overdensity in the Outskirts of M31

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    We present deep HST/ACS observations of the G1 clump, a distinct stellar overdensity lying at ~30 kpc along the south-western major axis of M31 close to the G1 globular cluster (Ferguson et al. 2002). Our well-populated colour-magnitude diagram reaches ~7 magnitudes below the red giant branch tip with 90% completeness, and allows the detection of various morphological features which can be used to derive detailed constraints on the age and metallicity of the constituent stellar population. We find that the colour-magnitude diagram is best described by a population with a large age range (>= 10 Gyr) and a relatively high mean metallicity [M/H]= -0.4. The spread in metallicity is constrained to be <=0.5 dex. The star formation rate in this region has declined over time, with the bulk of the stellar mass having formed >6 Gyr ago. Nonetheless, a non-negligible mass fraction (approximately 10%) of the population has formed in the last 2 Gyr. We discuss the nature of the G1 Clump in light of these new stellar population constraints and argue that the combination of stellar content and physical size make it unlikely that the structure is the remnant of an accreted dwarf galaxy. Instead, the strong similarity between the stellar content of the G1 Clump and that of the M31 outer disk suggests the substructure is a fragment of the outer disk, perhaps torn off from the main body during a past accretion/merger event; this interpretation is consistent with extant kinematical data. If this interpretation is correct, our analysis of the stellar content provides further evidence that the outskirts of large disk galaxies have been in place for a significant time.Comment: Accepted for publication in AJ. 13 pages, 12 figures. Figure 1, 5, 9, and 10 at reduced resolution. High resolution version available at http://www.astro.lu.se/~daniel/g1/g1.p

    Comparative performance of bone char-based filters for the removal of fluoride from drinking water

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    There is a great need for effective, reliable and inexpensive filters for the removal of fluoride for the millions of people affected in low and middle-income countries. This paper compares field and laboratory performance of bone char (BC) filters and filters, known as contact precipitation (CP), based on a combination of bone char and calcium-phosphate pellets

    The Stellar Populations of M31 Halo Substructure

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    We present the first results from our survey of stellar substructure in the outskirts of M31 using the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope. We discuss the stellar populations associated with five prominent stellar overdensities discovered during the course of our panoramic ground-based imaging survey with the Isaac Newton Telescope Wide-Field Camera (INT WFC); a sixth pointing targets a region of `clean' halo. The colour-magnitude diagrams (CMDs), which contain between ~10,000--90,000 stars and reach four magnitudes below the horizontal branch, reveal clear variations in morphology between most fields, indicating that the age and/or metallicity mix of stars is not constant at large radius. This directly confirms the existence of large-scale population inhomogeneities within the halo of M31 and lends further support to the notion that M31 has formed, at least in part, through satellite accretions. We find a striking similarity between the populations of the giant stellar stream and those of another overdensity, the NE shelf, which lies north-east of the galaxy center. If these overdensities are associated with the same population, then the difference in their red clump magnitudes implies the NE shelf lies in front of the stream by several tens of kpc, in good agreement with recent orbit calculations for the stream progenitor.Comment: 5 pages, 3 figurs, ApJL accepte
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