455 research outputs found

    Microsatellite markers for Dictyochloropsis reticulata (Trebouxiophyceae), the symbiotic alga of the lichen Lobaria pulmonaria (L.)

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    We isolated and characterized eight microsatellite markers for Dictyochloropsis reticulata, the primary photosynthetic partner of the epiphytic lichen Lobaria pulmonaria. These are the first microsatellite loci reported for a lichen symbiotic alga. These polymorphic markers will be useful for investigating spatial genetic structure, biogeography and dispersal of this eukaryotic alga and will generally shed light on the coevolution of the green-algal lichen symbiose

    Historiografija u političkoj komunikaciji – kako Josip Horvat pišući o prošlom želi mijenjati suvremenost1

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    Jedan od modusa na koji se politička poruka može komunicirati recipijentima jest posredovanje ideologije kroz priču o prošlim događajima, a u ovom se radu analizira konkretan slučaj – biografije historijskih ličnosti novinara i publicista Josipa Horvata iz 30-ih godina 20. stoljeća. Uklapanjem naravnog u određenu narativnu shemu Horvat želi oblikovati određenu političku zajednicu. Horvat svoj povijesni diskurs gradi, s jedne strane, na postupcima koji ovjerovljavaju njegovu priču, a s druge ga usmjerava kako bi postigao određeni ideološki efekt. Kao istinosni postupci izdvajaju se citiranje, kronologija, toponimija i sl, a kao postupci koji naglašavaju fikcionalnost antiteza, inscenacija, ispuštanje događaja i rekonstrukcija nepoznatog. Sudjelujući u društvenoj komunikaciji koja je tematizirala pitanja organizacije društva i raspodjele moći, Horvat je slikovitošću proizvodio ekspresivnost te usmjeravao imaginaciju čitatelja s namjerom izazivanja političke mobilizacije. Spajajući kontingentno i literarno proizvodi hibrid: priču napisanu s predumišljajem koja snagu uvjeravanja čitatelja crpi na svojoj vezi s istinitim, a sve u svrhu posredovanja svoje liberalne ideologije

    Learning to program using immersive approaches: A case study learning SAS®, IBM Bluemix and Watson Analytics

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    Learning to program is an activity which needs the learner to develop a range of new skills. Traditionally, this has been achieved in Universities by a presenting a series of structured lectures and tutorials covering the syntax and grammar of the language. This approach often leads to disengagement by many of the weaker students. It is becoming clear that this may not be the most effective approach in the twenty first century as a result of the continuous development of software packages which leads to the need to continually revise the teaching materials. In addition, modern millennial students demand engaging modes of learning that al-so prepare them for employment. This paper evaluates an approach which pro-vides a directed, immersive learning approach that mirrors the real world of em-ployment, develops both the requisite technical skills together with the fundamen-tal soft skills necessary for employment and prepares the students for lifelong learning and development and maintenance of new skills and languages. It also provides an intensely engaging environment that allows students to demonstrate the wide range of technical and soft skills that are necessary for a successful ca-reer. This approach also leads to high levels of achievement from the students and reduces stress levels in the academics leading the courses. The approach should be applicable to most STEM subjects which require the use of specialist software packages

    Novel Genotyping Tools for Investigating Transmission Dynamics of Plasmodium falciparum

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    Background. Differentiation between gametocyte-producing Plasmodium falciparum clones depends on both high levels of stage-specific transcripts and high genetic diversity of the selected genotyping marker obtained by a high-resolution typing method. By analyzing consecutive samples of one host, the contribution of each infecting clone to transmission and the dynamics of gametocyte production in multiclone infections can be studied. Methods. We have evaluated capillary electrophoresis based differentiation of 6 length-polymorphic gametocyte genes. RNA and DNA of 25 µL whole blood from 46 individuals from Burkina Faso were simultaneously genotyped. Results. Highest discrimination power was achieved by pfs230 with 18 alleles, followed by pfg377 with 15 alleles. When assays were performed in parallel on RNA and DNA, 85.7% of all pfs230 samples and 59.5% of all pfg377 samples contained at least one matching genotype in DNA and RNA. Conclusions. The imperfect detection in both, DNA and RNA, was identified as major limitation for investigating transmission dynamics, owing primarily to the volume of blood processed and the incomplete representation of all clones in the sample tested. Abundant low-density gametocyte carriers impede clone detectability, which may be improved by analyzing larger volumes and detecting initially sequestered gametocyte clones in follow-up sample

    Evaluation of Plasmodium vivax Genotyping Markers for Molecular Monitoring in Clinical Trials

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    BackgroundMany antimalarial interventions are accompanied by molecular monitoring of parasite infections, and a number of molecular typing techniques based on different polymorphic marker genes are used. Here, we describe a genotyping technique that provides a fast and precise approach to study Plasmodium vivax infection dynamics during circumstances in which individual clones must be followed over time. The method was tested with samples from an in vivo drug efficacy study MethodsThe sizes of polymerase chain reaction fragments were evaluated by capillary electrophoresis to determine the extent of size polymorphism for 9 potential genetic markers (5 genes of merozoite surface proteins [msp] and 4 microsatellites) in 93-108 P. vivax-positive blood samples from 3 villages in Papua New Guinea ResultsThe microsatellites MS16 and Pv3.27 showed the greatest diversity in the study area, with 66 and 31 different alleles, respectively, followed by 2 fragments of msp1 and 2 other microsatellites. msp3α, msp4 and msp5 revealed limited polymorphism ConclusionsEven for the most diverse markers, the highest allelic frequencies reached 6% (MS16) or 13% (Pv3.27). To reduce the theoretical probability of superinfection with parasites that have the same haplotype as that detected at baseline, we propose to combine at least 2 markers for genotyping individual P. vivax infection

    The usefulness of twenty-four molecular markers in predicting treatment outcome with combination therapy of amodiaquine plus sulphadoxine-pyrimethamine against falciparum malaria in Papua New Guinea

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    <p>Abstract</p> <p>Background</p> <p>In Papua New Guinea (PNG), combination therapy with amodiaquine (AQ) or chloroquine (CQ) plus sulphadoxine-pyrimethamine (SP) was introduced as first-line treatment against uncomplicated malaria in 2000.</p> <p>Methods</p> <p>We assessed <it>in vivo </it>treatment failure rates with AQ+SP in two different areas in PNG and twenty-four molecular drug resistance markers of <it>Plasmodium falciparum </it>were characterized in pre-treatment samples. The aim of the study was to investigate the association between infecting genotype and treatment response in order to identify useful predictors of treatment failure with AQ+SP.</p> <p>Results</p> <p>In 2004, Day-28 treatment failure rates for AQ+SP were 29% in the Karimui and 19% in the South Wosera area, respectively. The strongest independent predictors for treatment failure with AQ+SP were <it>pfmdr1 </it>N86Y (OR = 7.87, <it>p </it>< 0.01) and <it>pfdhps </it>A437G (OR = 3.44, <it>p </it>< 0.01). Mutations found in CQ/AQ related markers <it>pfcrt </it>K76T, A220S, N326D, and I356L did not help to increase the predictive value, the most likely reason being that these mutations reached almost fixed levels. Though mutations in SP related markers <it>pfdhfr </it>S108N and C59R were not associated with treatment failure, they increased the predictive value of <it>pfdhps </it>A437G. The difference in treatment failure rate in the two sites was reflected in the corresponding genetic profile of the parasite populations, with significant differences seen in the allele frequencies of mutant <it>pfmdr1 </it>N86Y, <it>pfmdr1 </it>Y184F, <it>pfcrt </it>A220S, and <it>pfdhps </it>A437G.</p> <p>Conclusion</p> <p>The study provides evidence for high levels of resistance to the combination regimen of AQ+SP in PNG and indicates which of the many molecular markers analysed are useful for the monitoring of parasite resistance to combinations with AQ+SP.</p

    Lack of multiple copies of pfmdr1 gene in Papua New Guinea

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    We describe here the results of an analysis of Plasmodium falciparum multidrug resistance protein 1 (pfmdr1) gene copy number from 440 field isolates from Papua New Guinea. No multiple copies of the gene were found, which corresponds to the lack of usage of mefloquine. These data extend regional knowledge about the distribution of multidrug-resistant P. falciparu

    Molecular Markers of In Vivo Plasmodium vivax Resistance to Amodiaquine Plus Sulfadoxine-Pyrimethamine: Mutations in pvdhfr and pvmdr1

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    Background. Molecular markers for sulfadoxine-pyrimethamine (SP) resistance in Plasmodium vivax have been reported. However, data on the molecular correlates involved in the development of resistance to 4-aminoquinolines and their association with the in vivo treatment response are scarce. Methods. We assessed pvdhfr (F57L/I, S58R, T61M, S117T/N, and I173F/L) and pvmdr1 (Y976F and F1076L) mutations in 94 patients who received amodiaquine (AQ) plus SP in Papua New Guinea (PNG). We then investigated the association between parasite genotype and treatment response. Results. The treatment failure (TF) rate reached 13%. Polymorphisms in pvdhfr F57L, S58R, T61M, and S117T/N and in pvmdr1 Y976F were detected in 60%, 67%, 20%, 40%, and 39% of the samples, respectively. The single mutant pvdhfr 57 showed the strongest association with TF (odds ratio [OR], 9.04; P=.01). The combined presence of the quadruple mutant pvdhfr 57L+58R+61M+117T and pvmdr1 mutation 976F was the best predictor of TF (OR, 8.56; P=.01). The difference in TF rates between sites was reflected in the genetic drug-resistance profile of the respective parasites. Conclusions. The present study identified a new molecular marker in pvmdr1 that is associated with the in vivo response to AQ+SP. We suggest suitable marker sets with which to monitor P. vivax resistance against AQ+SP in countries where these drugs are use

    Plasmodium falciparum resistance to anti-malarial drugs in Papua New Guinea: evaluation of a community-based approach for the molecular monitoring of resistance

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    ABSTRACT: BACKGROUND: Molecular monitoring of parasite resistance has become an important complementary tool in establishing rational anti-malarial drug policies. Community surveys provide a representative sample of the parasite population and can be carried out more rapidly than accrual of samples from clinical cases, but it is not known whether the frequencies of genetic resistance markers in clinical cases differ from those in the overall population, or whether such community surveys can provide good predictions of treatment failure rates. METHODS: Between 2003 and 2005, in vivo drug efficacy of amodiaquine or chloroquine plus sulphadoxine-pyrimethamine was determined at three sites in Papua New Guinea. The genetic drug resistance profile (i.e., 33 single nucleotide polymorphisms in Plasmodium falciparum crt, mdr1, dhfr, dhps, and ATPase6) was concurrently assessed in 639 community samples collected in the catchment areas of the respective health facilities by using a DNA microarray-based method. Mutant allele and haplotype frequencies were determined and their relationship with treatment failure rates at each site in each year was investigated. RESULTS: PCR-corrected in vivo treatment failure rates were between 12% and 28% and varied by site and year with variable longitudinal trends. In the community samples, the frequencies of mutations in pfcrt and pfmdr1 were high and did not show significant changes over time. Mutant allele frequencies in pfdhfr were moderate and those in pfdhps were low. No mutations were detected in pfATPase6. There was much more variation between sites than temporal, within-site, variation in allele and haplotype frequencies. This variation did not correlate well with treatment failure rates. Allele and haplotype frequencies were very similar in clinical and community samples from the same site. CONCLUSIONS: The relationship between parasite genetics and in vivo treatment failure rate is not straightforward. The frequencies of genetic anti-malarial resistance markers appear to be very similar in community and clinical samples, but cannot be used to make precise predictions of clinical outcome. Thus, indicators based on molecular data have to be considered with caution and interpreted in the local context, especially with regard to prior drug usage and level of pre-existing immunity. Testing community samples for molecular drug resistance markers is a complementary tool that should help decision-making for the best treatment options and appropriate potential alternative

    Transformations of Infrastructure Systems: Report of the second International Conference of the Research Training Group KRITIS at the Technical University Darmstadt, Germany

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    On the 4th and 5th of November 2021, more than 50 scholars from different disciplines and countries came together in an online conference to discuss the multiple aspects of Transformations of Infrastructure Systems at the second international conference organized by the Research Training Group KRITIS at the Technical University of Darmstadt, Germany. The focus of this conference was on the dynamic and changing nature of infrastructure systems and describing, understanding, and explaining transformation processes of infrastructures. Within the four multidisciplinary panels (Safety, Cultures, Governance, and both Temporality and Spatiality) the participants shared their research and knowledge on various aspects of transformation of infrastructure Systems. The conference gave an insight into the triggers of transformations and highlighted the conditions under which they take place and the consequences. The keynote lectures by Prof. Dr. Timothy Moss (Humboldt University of Berlin), Dr. Anique Hommels (Maastricht University), and Niklas Vespermann (Federal Network Agency, Germany) further highlighted and deepened the aspects relevant to this context
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