275 research outputs found

    The research-teaching nexus from the Portuguese academics’ perspective: a qualitative case study in a school of social sciences and humanities

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    This paper reports on a study conducted as part of an action-research project—INTEGRA I&E—aiming to promote the research and teaching (R&T) nexus at the School of Social Sciences and Humanities of a Research University in Lisbon, Portugal (Instituto Universitário de Lisboa, ISCTE-IUL). This study set out to investigate a multi-informant perspective of the academics’ rhetoric (conceptions, perception of barriers/facilitators and consequences) concerning the nexus, which can be considered at different levels of the curricular and organizational structure. Focus groups were conducted with 26 professors and 8 researchers from six different disciplinary areas and, afterwards, recorded and transcribed. A content analysis was used to categorize and quantify participants’ responses. Four themes emerged: practices linking R&T, barriers, facilitators and consequences of the nexus. Different levels of analysis were identified for each theme, namely, the level of ISCTE-IUL, Research Centers, Departments, Courses and Classes. Some disciplinary differences were also encountered. This study contributes with a multi-informant and multi-level perspective of academics’ conceptions of the R&T nexus in a Portuguese research-oriented university.info:eu-repo/semantics/acceptedVersio

    An integral equation method for the inverse conductivity problem

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    We present an image reconstruction algorithm for the Inverse Conductivity Problem based on reformulating the problem in terms of integral equations. We use as data the values of injected electric currents and of the corresponding induced boundary potentials, as well as the boundary values of the electrical conductivity. We have used a priori information to find a regularized conductivity distribution by first solving a Fredholm integral equation of the second kind for the Laplacian of the potential, and then by solving a first order partial differential equation for the regularized conductivity itself. Many of the calculations involved in the method can be achieved analytically using the eigenfunctions of an integral operator defined in the paper.Comment: 15 pages, 8 figure

    The cohesin ring concatenates sister DNA molecules

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    Sister chromatid cohesion, which is essential for mitosis, is mediated by a multi-subunit protein complex called cohesin whose Scc1, Smc1, and Smc3 subunits form a tripartite ring structure. It has been proposed that cohesin holds sister DNAs together by trapping them inside its ring. To test this, we used site-specific cross-linking to create chemical connections at the three interfaces between the ring’s three constituent polypeptides, thereby creating covalently closed cohesin rings. As predicted by the ring entrapment model, this procedure produces dimeric DNA/cohesin structures that are resistant to protein denaturation. We conclude that cohesin rings concatenate individual sister minichromosome DNAs

    Integrated Transcriptomics, Metabolomics, and Lipidomics Profiling in Rat Lung, Blood, and Serum for Assessment of Laser Printer-Emitted Nanoparticle Inhalation Exposure-Induced Disease Risks

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    settings Open AccessArticle Integrated Transcriptomics, Metabolomics, and Lipidomics Profiling in Rat Lung, Blood, and Serum for Assessment of Laser Printer-Emitted Nanoparticle Inhalation Exposure-Induced Disease Risks by Nancy Lan Guo 1,*,Tuang Yeow Poh 2,Sandra Pirela 3,Mariana T. Farcas 4,Sanjay H. Chotirmall 2,Wai Kin Tham 5,Sunil S. Adav 5,Qing Ye 1,Yongyue Wei 6,Sipeng Shen 2,David C. Christiani 2,Kee Woei Ng 3,7,8,Treye Thomas 9,Yong Qian 4 andPhilip Demokritou 3 1 West Virginia University Cancer Institute/School of Public Health, West Virginia University, Morgantown, WV 26506, USA 2 Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore 3 Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, T. H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA 4 Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA 5 Singapore Phenome Centre, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, Singapore 6 Key Lab for Modern Toxicology, Department of Epidemiology and Biostatistics and Ministry of Education (MOE), School of Public Health, Nanjing Medical University, Nanjing 210029, China 7 School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore 8 Environmental Chemistry and Materials Centre, Nanyang Environment & Water Research Institute, Singapore 637141, Singapore 9 Office of Hazard Identification and Reduction, U.S. Consumer Product Safety Commission, Rockville, MD 20814, USA * Author to whom correspondence should be addressed. Int. J. Mol. Sci. 2019, 20(24), 6348; https://doi.org/10.3390/ijms20246348 Received: 2 December 2019 / Revised: 12 December 2019 / Accepted: 13 December 2019 / Published: 16 December 2019 (This article belongs to the Special Issue Advances in Nanostructured Materials between Pharmaceutics and Biomedicine) Download PDF Browse Figures Review Reports Cite This Paper Abstract Laser printer-emitted nanoparticles (PEPs) generated from toners during printing represent one of the most common types of life cycle released particulate matter from nano-enabled products. Toxicological assessment of PEPs is therefore important for occupational and consumer health protection. Our group recently reported exposure to PEPs induces adverse cardiovascular responses including hypertension and arrythmia via monitoring left ventricular pressure and electrocardiogram in rats. This study employed genome-wide mRNA and miRNA profiling in rat lung and blood integrated with metabolomics and lipidomics profiling in rat serum to identify biomarkers for assessing PEPs-induced disease risks. Whole-body inhalation of PEPs perturbed transcriptional activities associated with cardiovascular dysfunction, metabolic syndrome, and neural disorders at every observed time point in both rat lung and blood during the 21 days of exposure. Furthermore, the systematic analysis revealed PEPs-induced transcriptomic changes linking to other disease risks in rats, including diabetes, congenital defects, auto-recessive disorders, physical deformation, and carcinogenesis. The results were also confirmed with global metabolomics profiling in rat serum. Among the validated metabolites and lipids, linoleic acid, arachidonic acid, docosahexanoic acid, and histidine showed significant variation in PEPs-exposed rat serum. Overall, the identified PEPs-induced dysregulated genes, molecular pathways and functions, and miRNA-mediated transcriptional activities provide important insights into the disease mechanisms. The discovered important mRNAs, miRNAs, lipids and metabolites may serve as candidate biomarkers for future occupational and medical surveillance studies. To the best of our knowledge, this is the first study systematically integrating in vivo, transcriptomics, metabolomics, and lipidomics to assess PEPs inhalation exposure-induced disease risks using a rat model

    Laboratory demonstration of a prozone-like effect in HRP2-detecting malaria rapid diagnostic tests: implications for clinical management

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    Background: Malaria rapid diagnostic tests (RDTs) are now widely used for prompt on-site diagnosis in remote endemic areas where reliable microscopy is absent. Aberrant results, whereby negative test results occur at high parasite densities, have been variously reported for over a decade and have led to questions regarding the reliability of the tests in clinical use. Methods. In the first trial, serial dilutions of recombinant HRP2 antigen were tested on an HRP2-detectiing RDT. In a second trial, serial dilutions of culture-derived Plasmodium falciparum parasites were tested against three HRP2-detecting RDTs. Results: A prozone-like effect occurred in RDTs at a high concentration of the target antigen, histidine-rich protein-2 (above 15,000 ng/ml), a level that corresponds to more than 312000 parasites per L. Similar results were noted on three RDT products using dilutions of cultured parasites up to a parasite density of 25%. While reduced line intensity was observed, no false negative results occurred. Conclusions: These results suggest that false-negative malaria RDT results will rarely occur due to a prozone-like effect in high-density infections, and other causes are more likely. However, RDT line intensity is poorly indicative of parasite density in high-density infections and RDTs should, therefore, not be considered quantitative. Immediate management of suspected severe malaria should rely on clinical assessment or microscopy. Evaluation against high concentrations of antigen should be considered in malaria RDT product development and lot-release testing, to ensure that very weak or false negative results will not occur at antigen concentrations that might be seen clinically

    Comparison of diagnostic methods for the detection and quantification of the four sympatric Plasmodium species in field samples from Papua New Guinea

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    Accurate diagnosis of Plasmodium infections is essential for malaria morbidity and mortality reduction in tropical areas. Despite great advantages of light microscopy (LM) for malaria diagnosis, its limited sensitivity is a critical shortfall for epidemiological studies. Robust molecular diagnostics tools are thus needed.; The present study describes the development of a duplex quantitative real time PCR (qPCR) assay, which specifically detects and quantifies the four human Plasmodium species. Performance of this method was compared to PCR-ligase detection reaction-fluorescent microsphere assay (PCR_LDR_FMA), nested PCR (nPCR) and LM, using field samples collected from 452 children one to five years of age from the Sepik area in Papua New Guinea. Agreement between diagnostic methods was calcualted using kappa statistics.; The agreement of qPCR with other molecular diagnostic methods was substantial for the detection of P. falciparum, but was moderate for the detection of P. vivax, P. malariae and P. ovale. P. falciparum and P. vivax prevalence by qPCR was 40.9% and 65.7% respectively. This compares to 43.8% and 73.2% by nPCR and 47.1% and 67.5% by PCR_LDR_FMA. P. malariae and P. ovale prevalence was 4.7% and 7.3% by qPCR, 3.3% and 3.8% by nPCR, and 7.7% and 4.4% by PCR_LDR_FMA. Prevalence by LM was lower for all four species, being 25.4% for P. falciparum, 54.9% for P. vivax, 2.4% for P. malariae and 0.0% for P. ovale. The quantification by qPCR closely correlated with microscopic quantification for P. falciparum and P. vivax samples (R2 = 0.825 and R2 = 0.505, respectively). The low prevalence of P. malariae and P. ovale did not permit a solid comparative analysis of quantification for these species.; The qPCR assay developed proved optimal for detection of all four Plasmodium species. Densities by LM were well reflected in quantification results by qPCR, whereby congruence was better for P. falciparum than for P. vivax. This likely is a consequence of the generally lower P. vivax densities. Easy performance of the qPCR assay, a less laborious workflow and reduced risk of contamination, together with reduced costs per sample through reduced reaction volume, opens the possibility to implement qPCR in endemic settings as a suitable diagnostic tool for large epidemiological studies

    Prozone in malaria rapid diagnostics tests: how many cases are missed?

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    <p>Abstract</p> <p>Background</p> <p>Prozone means false-negative or false-low results in antigen-antibody reactions, due to an excess of either antigen or antibody. The present study prospectively assessed its frequency for malaria rapid diagnostic tests (RDTs) and <it>Plasmodium falciparum </it>samples in an endemic field setting.</p> <p>Methods</p> <p>From January to April 2010, blood samples with <it>P. falciparum </it>high parasitaemia (≥ 4% red blood cells infected) were obtained from patients presenting at the Provincial Hospital of Tete (Mozambique). Samples were tested undiluted and 10-fold diluted in saline with a panel of RDTs and results were scored for line intensity (no line visible, faint, weak, medium and strong). Prozone was defined as a sample which showed no visible test line or a faint or weak test line when tested undiluted, and a visible test line of higher intensity when tested 10-fold diluted, as observed by two blinded observers and upon duplicate testing.</p> <p>Results</p> <p>A total of 873/7,543 (11.6%) samples showed <it>P. falciparum</it>, 92 (10.5%) had high parasitaemia and 76 were available for prozone testing. None of the two Pf-pLDH RDTs, but all six HRP-2 RDTs showed prozone, at frequencies between 6.7% and 38.2%. Negative and faint HRP-2 lines accounted for four (3.8%) and 15 (14.4%) of the 104 prozone results in two RDT brands. For the most affected brand, the proportions of prozone with no visible or faint HRP-2 lines were 10.9% (CI: 5.34-19.08), 1.2% (CI: 0.55-2.10) and 0.1% (CI: 0.06-0.24) among samples with high parasitaemia, all positive samples and all submitted samples respectively. Prozone occurred mainly, but not exclusively, among young children.</p> <p>Conclusion</p> <p>Prozone occurs at different frequency and intensity in HRP-2 RDTs and may decrease diagnostic accuracy in the most affected RDTs.</p

    The fourth wave of Portuguese emigration: Austerity policies, European peripheries and postcolonial continuities

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    Little is known about emigration in European countries. Migratory pressure and the recent refugee crisis have helped keep academic attention over the last few decades focused on immigration, asylum and integration in Europe. However, these dynamics promoting entries into European countries coexist with other fair-ly significant dynamics promoting departures from these countries. The sovereign debt crisis coupled with austerity policies that asymmetrically affected Europe’s peripheral countries have increased emigration in various European countries. Our book aims to counter the invisibility of emigration from European countries in the literature by examining the particularities of the Portuguese case. In methodological terms, the book compiles the work of authors from different academic backgrounds who have conducted empirical research using a wide vari-ety of extensive and intensive methods. It is argued that when analysing recent Portuguese emigration it is important to examine in further detail: i) the impact of the 2008 economic and financial crisis and the austerity policies that followed in its wake; ii) south-north emigration in Europe; iii) north-south emigration outside Europe and post-colonial continuities; iv) the importance of reassessing the exist-ing model of Southern European migration; v) highly skilled and less skilled mi-gration; and finally, vi) emigrants’ and their descendants’ identities.info:eu-repo/semantics/publishedVersio

    Percentage of Patients with Preventable Adverse Drug Reactions and Preventability of Adverse Drug Reactions – A Meta-Analysis

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    BACKGROUND: Numerous observational studies suggest that preventable adverse drug reactions are a significant burden in healthcare, but no meta-analysis using a standardised definition for adverse drug reactions exists. The aim of the study was to estimate the percentage of patients with preventable adverse drug reactions and the preventability of adverse drug reactions in adult outpatients and inpatients. METHODS: Studies were identified through searching Cochrane, CINAHL, EMBASE, IPA, Medline, PsycINFO and Web of Science in September 2010, and by hand searching the reference lists of identified papers. Original peer-reviewed research articles in English that defined adverse drug reactions according to WHO's or similar definition and assessed preventability were included. Disease or treatment specific studies were excluded. Meta-analysis on the percentage of patients with preventable adverse drug reactions and the preventability of adverse drug reactions was conducted. RESULTS: Data were analysed from 16 original studies on outpatients with 48797 emergency visits or hospital admissions and from 8 studies involving 24128 inpatients. No studies in primary care were identified. Among adult outpatients, 2.0% (95% confidence interval (CI): 1.2-3.2%) had preventable adverse drug reactions and 52% (95% CI: 42-62%) of adverse drug reactions were preventable. Among inpatients, 1.6% (95% CI: 0.1-51%) had preventable adverse drug reactions and 45% (95% CI: 33-58%) of adverse drug reactions were preventable. CONCLUSIONS: This meta-analysis corroborates that preventable adverse drug reactions are a significant burden to healthcare among adult outpatients. Among both outpatients and inpatients, approximately half of adverse drug reactions are preventable, demonstrating that further evidence on prevention strategies is required. The percentage of patients with preventable adverse drug reactions among inpatients and in primary care is largely unknown and should be investigated in future research
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