2,909 research outputs found

    Cytoadherence and virulence - the case of Plasmodium knowlesi malaria.

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    BACKGROUND: Cytoadherence of infected red blood cells to brain endothelium is causally implicated in malarial coma, one of the severe manifestations of falciparum malaria. Cytoadherence is mediated by specific binding of variant parasite antigens, expressed on the surface of infected erythrocytes, to endothelial receptors including, ICAM-1, VCAM and CD36. In fatal cases of severe falciparum malaria with coma, blood vessels in the brain are characteristically congested with infected erythrocytes. Brain sections from a fatal case of knowlesi malaria, but without coma, were similarly congested with infected erythrocytes. The objective of this study was to determine the binding phenotype of Plasmodium knowlesi infected human erythrocytes to recombinant human ICAM-1, VCAM and CD36. METHODS: Five patients with PCR-confirmed P. knowlesi malaria were recruited into the study with consent between April and August 2010. Pre-treatment venous blood was washed and cultured ex vivo to increase the proportion of schizont-infected erythrocytes. Cultured blood was seeded into Petri dishes with triplicate areas coated with ICAM-1, VCAM and CD36. Following incubation at 37°C for one hour the dishes were washed and the number of infected erythrocytes bound/mm2 to PBS control areas and to recombinant human ICAM-1 VCAM and CD36 coated areas were recorded. Each assay was performed in duplicate. Assay performance was monitored with the Plasmodium falciparum clone HB3. RESULTS: Blood samples were cultured ex vivo for up to 14.5 h (mean 11.3 ± 1.9 h) to increase the relative proportion of mature trophozoite and schizont-infected red blood cells to at least 50% (mean 65.8 ± 17.51%). Three (60%) isolates bound significantly to ICAM-1 and VCAM, one (20%) isolate bound to VCAM and none of the five bound significantly to CD36. CONCLUSIONS: Plasmodium knowlesi infected erythrocytes from human subjects bind in a specific but variable manner to the inducible endothelial receptors ICAM-1 and VCAM. Binding to the constitutively-expressed endothelial receptor CD36 was not detected. Further work will be required to define the pathological consequences of these interactions

    Comparing the efficacy of four brief inductions in boosting short-term creativity

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    Augmenting creative performance has the potential to benefit both the individual and our society. Several studies have evaluated the impact of different behavioral training or induction methods on creativity. However, the findings are mixed and sometimes contradictory. Four different short-term induction methods which differed along two information processing dimensions – modality and demand – were compared within a single experimental paradigm alongside a non-induction control condition to determine which was the most effective at improving creativity. A comparison on the experimental inductions revealed that low demand induction methods boosted creativity more than high demand induction methods. However, this pattern was not maintained when comparisons included the non-induction control. These findings provide insights on factors that need to be taken into account at the level of experimental design in order to be able to evaluate the efficacy of different induction and training methods on creativity

    Comparing Haemozoin count and Parasitaemia in the Prognosis of severe Plasmodium Falciparum Malaria in Children and non-immune adults in Kano-Nigeria

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    This study compared the value of pigment containing leucocytes (neutrophils and monocytes) counts and the malaria parasite density in the prognosis of severe malaria on four hundred and twenty (420) patients with clinical evidence of severe malaria in Kano-Nigeria. Three clinical groups comprising patients with impaired consciousness, patients with cerebral malaria and those with severe anaemia were identified. Samples were analysed for Malaria parasitemia and pigment count Giemsa’s thick and Leishman’s thin film respectively. Patients with impaired consciousness (n=217) recorded the highest malaria pigment count of 342.86 (±177.34) monocytes pigments/microliter. The highest parasite count of 234,962 (±264.5) per microliter was recorded among the cerebral malaria group. Patients with severe malaria and anaemia had the least neutrophils pigment and parasite counts of 219.0 (±140.96)/microliter and 212,232(±12.61)/microliter respectively. A linear relationship between the malaria parasite count and the Intraneutrophilic malaria pigment count in severe malaria was demonstrated. Pigment count proved a higher prognostic value in severe malaria compared to Parasitaemia.Keywords: Haemozoin, Plasmodium falciparum, Parasitaemia, Malari

    Evaluation of real-time PCR for diagnosis of Bordetella pertussis infection

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    BACKGROUND: Nucleic acid amplification of the IS481 region by PCR is more sensitive than culture for detection and diagnosis of Bordetella pertussis but the assay has known cross-reactivity for Bordetella holmesii and its use as a routine diagnostic assay has not been widely evaluated. METHODS: The objectives of this study were: 1) to assess the diagnostic utility of real-time IS481 PCR by comparison of results with culture and direct fluorescent antigen (DFA) testing for B. pertussis, 2) to employ a PCR assay designed against a different insertion sequence (IS1001) to assess the incidence of B. holmesii in symptomatic individuals and 3) to design and evaluate a new PCR-based assay which could be used for B. pertussis confirmation. A total of 808 nasopharyngeal specimens were included in the study the majority of which were submitted in charcoal transport medium (88%) with the rest submitted in Regan-Lowe medium. RESULTS: Concordant results for PCR, DFA and culture were obtained for 21 B. pertussis positive and 729 B. pertussis negative specimens. DFA was prone to false positive and negative reactions when compared with both PCR and culture. The IS481 PCR identified 28 positive results for specimens that were DFA and culture negative. A novel real-time PCR targeting the B. pertussis toxin promoter was found to be specific and useful for confirming the majority of IS481 positive specimens as B. pertussis. B. holmesii was not detected in any of the submitted samples. CONCLUSION: The potential pick up of B. holmesii by the IS481 PCR had minimal diagnostic relevance in the Alberta population during the time period of our study. The IS481 PCR assay is now used in our laboratory routinely for front-line screening of samples for B. pertussis with associated enhancement in diagnostic sensitivity compared with DFA and culture. Retrospectively, patients' samples are batched and tested by the IS1001 MB and TPR assays for research purposes and to ensure there is no change in B. holmesii incidence in the population

    Possible alternative for national supply of seed potatoes (Solanum tuberosum L.) from in vitro culture at the Agro-physio-genetic and Plants Biotechnology laboratory of IPR / IFRA of Katibougou, Mali

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    The enhancement of the potential for reducing food insecurity and poverty through potato cultivation in Mali is largely limited by difficult access to quality seed. In trying to find ways to reduce these shortcomings outlined above that work has been done. The objective of this work was to assess the economic profitability of the local potato seed sourcing scheme from in vitro propagation and to analyze the competitiveness of the sourcing scheme from imported elite seed. The technical and economic feasibility of the local potato seed supply scheme was assessed at five levels. The first concerns the production of vitro-plants in the laboratory, the second the production of mini zero generation tubers (G0). Regarding the other three levels of evaluation, they were carried out in collaboration with the seed cooperatives by successive multiplication from mini-tubers to obtain seeds of one “G1”, two “G2” and three “G3” generations". The profitability of the procurement scheme from the elite imported and multiplied once seed was evaluated in order to analyze its competitiveness in relation to the local circuit. The valuation indicates positive profit margins. However, it should be noted that the economic efficiency coefficients of vitro-propagation (0.77) and tunnel multiplication (0.75) are less than 1. The production cost of one kilogram of G3 is equal to at 463.39 F CFA. A profit margin of 456.61 F CFA / kg emerges between this unit production cost and the selling price of imported seeds, which amounts on average to 920 F CFA / kg. The production of plants is technically feasible and profitable with a cost price of one kg of G3 in the order of 500 to 600 F CFA against 900 to 1000 F CFA / kg for imported seed. La valorisation du potentiel de réduction de l’insécurité alimentaire et de la pauvreté à travers la culture de la pomme de terre au Mali est limitée en grande partie par l’accès difficile à la semence de qualité. En essayant de trouver des moyens pour réduire ces insuffisances soulignées ci-dessus que ce travail a été effectué. Le présent travail avait pour objectif d’évaluer la rentabilité économique du schéma d’approvisionnement locale en semences de pomme de terre à partir de la vitro propagation et d’analyser la compétitivité du schéma d’approvisionnement à partir de la semence élite importées. La faisabilité technico-économique du schéma d’approvisionnement local en semences de pomme de terre était évaluée à cinq niveaux. Le premier concerne la production de vitro-plants au laboratoire, le deuxième la production de mini tubercules de génération zéro (G0). Pour ce qui concerne les trois autres niveaux d’évaluation, ils ont été réalisés en collaboration avec les coopératives semencières par multiplications successives à partir de mini-tubercules pour obtenir des semences de génération une «G1», deux «G2» et trois «G3». La rentabilité, du schéma d’approvisionnement à partir de la semence élite importée et multipliée une fois, a été évaluée en vue d’analyser sa compétitivité en rapport avec le circuit local. L’évaluation indique des marges bénéficiaires positives. Cependant, il faut remarquer que les coefficients d’efficacité économiques de la vitro-propagation (0,77) et de la multiplication sous tunnels (0,75) sont inférieurs à 1. Le coût de production d’un kilogramme de G3 est égal à 463,39 F CFA. Une marge bénéficiaire de 456,61 F CFA / kg se dégage entre ce coût de production unitaire et le prix de vente des semences importées qui s’élève en moyenne à 920 F CFA / kg. La production de plants est techniquement faisable et rentable avec un coût de revient d’un kg de G3 de l’ordre de 500 à 600 F CFA contre 900 à 1 000 F CFA / kg pour la semence importée

    Breastfeeding in the community—how can partners/fathers help? A systematic review

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    Support from partners/fathers and families can play a significant role in a mother’s decision to initiate, continue or cease breastfeeding postnatally. This study systematically reviewed published studies to determine the impact of specific types of partner support on breastfeeding initiation, duration and exclusivity. We used the 2015 Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines for the review. Seven computerized bibliographic databases (Embase, ProQuest Central, Scopus, PsycINFO, Web of Science, MEDLINE/PubMed and CINAHL) were searched. Of a total of 695 articles retrieved from the databases, seven studies met the inclusion criteria and reported on breastfeeding initiation, duration and exclusivity. Four of the seven studies found that partner support in the form of verbal encouragement to new mothers increased breastfeeding duration and exclusivity. Other types of partner supportive actions that led to improved breastfeeding behavior included sensitivity of the partner to the nursing mother’s needs, assistance in preventing and managing breastfeeding difficulties, and helping with household and child care duties. This review showed that specific supportive actions of partners/fathers in the community positively improved breastfeeding practices. To maximise the impact of breastfeeding policies and interventions among new mothers, breastfeeding programmes should consider the involvement of partners/fathers and their specific roles

    Selective Deuterium Ion Acceleration Using the Vulcan PW Laser

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    We report on the successful demonstration of selective acceleration of deuterium ions by target-normal sheath acceleration (TNSA) with a high-energy petawatt laser. TNSA typically produces a multi-species ion beam that originates from the intrinsic hydrocarbon and water vapor contaminants on the target surface. Using the method first developed by Morrison, et al.,1^{1} an ion beam with >>99%\% deuterium ions and peak energy 14 MeV/nucleon is produced with a 200 J, 700 fs, >1020W/cm2>10^{20} W/cm^{2} laser pulse by cryogenically freezing heavy water (D2_{2}O) vapor onto the rear surface of the target prior to the shot. Within the range of our detectors (0-8.5^{\circ}), we find laser-to-deuterium-ion energy conversion efficiency of 4.3%\% above 0.7 MeV/nucleon while a conservative estimate of the total beam gives a conversion efficiency of 9.4%\%.Comment: 5 pages, 5 figure

    Prevalence, trends, and drivers of the utilization of unskilled birth attendants during democratic governance in Nigeria from 1999 to 2018

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    Comprehensive epidemiological data on prevalence, trends, and determinants of the use of unskilled birth attendants (traditional birth attendants (TBAs) and other unskilled birth attendants) are essential to policy decision-makers and health practitioners, to guide efforts and resource allocation. This study investigated the prevalence, trends, and drivers of the utilization of unskilled birth attendants during democratic governance in Nigeria from 1999 to 2018. The study used the Nigeria Demographic and Health Surveys data for the years 1999 (n = 3552), 2003 (n = 6029), 2008 (n = 28,647), 2013 (n = 31,482), and 2018 (34,193). Multivariate multinomial logistic regression was used to investigate the association between socioeconomic, demographic, health-service, and community-level factors with the utilization of TBAs and other unskilled birth attendants in Nigeria. Between 1999 and 2018, the study showed that the prevalence of TBA-assisted delivery remained unchanged (20.7%; 95% CI: 18.0–23.7% in 1999 and 20.5%; 95% CI: 18.9–22.1% in 2018). The prevalence of other-unskilled-birth-attendant use declined significantly from 45.5% (95% CI: 41.1–49.7%) in 2003 to 36.2% (95% CI: 34.5–38.0%) in 2018. Higher parental education, maternal employment, belonging to rich households, higher maternal age (35–49 years), frequent antenatal care (ANC) (≥4) visits, the proximity of health facilities, and female autonomy in households were associated with lower odds of unskilled birth attendants’ utilization. Rural residence, geopolitical region, lower maternal age (15–24 years), and higher birth interval (≥2 years) were associated with higher odds of unskilled-birth-attendant-assisted deliveries. Reducing births assisted by unskilled birth attendants in Nigeria would require prioritized and scaled-up maternal health efforts that target all women, especially those from low socioeconomic backgrounds, those who do not attend antenatal care, and/or those who reside in rural areas

    Adaptive power control aware depth routing in underwater sensor networks

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    Underwater acoustic sensor network (UASN) refers to a procedure that promotes a broad spectrum of aquatic applications. UASNs can be practically applied in seismic checking, ocean mine identification, resource exploration, pollution checking, and disaster avoidance. UASN confronts many difficulties and issues, such as low bandwidth, node movements, propagation delay, 3D arrangement, energy limitation, and high-cost production and arrangement costs caused by antagonistic underwater situations. Underwater wireless sensor networks (UWSNs) are considered a major issue being encountered in energy management because of the limited battery power of their nodes. Moreover, the harsh underwater environment requires vendors to design and deploy energy-hungry devices to fulfil the communication requirements and maintain an acceptable quality of service. Moreover, increased transmission power levels result in higher channel interference, thereby increasing packet loss. Considering the facts mentioned above, this research presents a controlled transmission power-based sparsity-aware energy-efficient clustering in UWSNs. The contributions of this technique is threefold. First, it uses the adaptive power control mechanism to utilize the sensor nodes’ battery and reduce channel interference effectively. Second, thresholds are defined to ensure successful communication. Third, clustering can be implemented in dense areas to decrease the repetitive transmission that ultimately affects the energy consumption of nodes and interference significantly. Additionally, mobile sinks are deployed to gather information locally to achieve the previously mentioned benefits. The suggested protocol is meticulously examined through extensive simulations and is validated through comparison with other advanced UWSN strategies. Findings show that the suggested protocol outperforms other procedures in terms of network lifetime and packet delivery ratio

    The Prevalence of Extreme Middle-Eastern Ideologies among Some Nigerians

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    Over the past decade, a small extremist Islamic sect agitating against Western civilization has grown to become the biggest challenge to Nigerian internal security, a serious threat to international security and peace, and has earned the country the unenviable international reputation of a terrorist state. The radicalization of members of the group is driven majorly by extreme Middle-Eastern Islamic religious ideologies. In this study, 99 Nigerian participants (51 Christians and 48 Muslims) completed the Assessment and Treatment of Radicalization Scale (ATRS; Loza, 2007; formally the Belief Diversity Scale, BDS; Loza, 2007). The ATRS is a 33-item, six subscale instrument that is designed to quantitatively measure Middle-Eastern extremist ideologies in areas of risk reported in the literature. Results demonstrated reliability and validity of the ATRS as well as indicated the prevalence of Middle-Eastern extremists’ ideologies among Nigerian Muslims. Current findings are consistent with those obtained from previous studies. These findings suggest that the ATRS could be used as an objective tool to measure Middle-Eastern religious extremism
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