523 research outputs found

    Platform Groene grondstoffen, werkgroep 1: duurzame productie en ontwikkeling van biomassa, deelpad: Aquatische biomassa

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    Het deelpad Aquatische Biomassa heeft een sterke internationale dimensie. Wereldwijd bestaat een groeiende belangstelling voor het aquatisch milieu (denk hierbij aan waterplanten, zoutwaterlandbouw, micro-algen en zeewieren) als leverancier van voedsel, grondstoffen en energie. Daarnaast is er grote aandacht voor watermanagement, met name gezien de problemen die zich aandienen t.a.v. de berging van regenwater en de beschikbaarheid van zoet water voor drinkwatervoorziening en de landbouw. In dit deelpad worden beide thema’s aan elkaar gekoppeld, zodat meerwaarde ontstaat voor duurzame ontwikkeling met een grote internationale uitstraling van biomassa voor grondstof- en energievoorzienin

    Pregnancy and Fetal Outcomes After Exposure to Mefloquine in the Pre- and Periconception Period and During Pregnancy

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    Pregnant women who travel to malarious areas and their clinicians need data on the safety of malaria chemoprophylaxis. The drug safety database analysis of mefloquine exposure in pregnancy showed that the birth defect prevalence and fetal loss in maternal, prospectively-monitored cases were comparable to background rates

    Differences in Discriminability and Response Bias on Rey Auditory Verbal Learning Test Delayed Recognition in Behavioral Variant Frontotemporal Dementia and Alzheimer’s Disease

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    Objective:Episodic memory is impaired in Alzheimer's disease (AD) dementia but thought to be relatively spared in behavioral variant frontotemporal dementia (bvFTD). This view is challenged by evidence of memory impairment in bvFTD. This study investigated differences in recognition memory performance between bvFTD and AD.Method:We performed a retrospective analysis on the recognition trial of the Rey Auditory Verbal Learning Test in patients with bvFTD (n = 85), AD (n = 55), and control participants (n = 59). Age- A nd education-adjusted between-group analysis was performed on the total score and indices of discriminative ability and response bias. Correlations between recognition and measures of memory, language, executive functioning, and construction were examined.Results:Patients with AD had a significantly lower total recognition score than patients with bvFTD (control 28.8 ± 1.5; bvFTD 24.8 ± 4.5; AD 23.4 ± 3.6, p <.01). Both bvFTD and AD had worse discriminative ability than controls (A' control 0.96 ± 0.03; bvFTD 0.87 ± 0.03; AD 0.84 ± 0.10, p <.01), but there was no difference in response bias (B" control 0.9 ± 0.2; bvFTD 1.6 ± 1.47; AD 1.4± 1.4, p <.01). AD had worse discriminability than bvFTD (p <.05). Discriminability was associated with memory for both patient groups (median correlation coefficient r =.34) and additionally associated with language (r =.31), but not executive functioning (r =-.03) in bvFTD. Response bias was unrelated to other cognitive functions (r =-.02).Conclusions:Discriminability, but not response bias, differentiated patients with bvFTD from AD. The presence of an impaired discrimination index suggests a "pure" (recognition) memory deficit in bvFTD

    Implementation and validation of ASL perfusion measurements for population imaging

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    Purpose: Pseudocontinuous arterial spin labeling (pCASL) allows for noninvasive measurement of regional cerebral blood flow (CBF), which has the potential to serve as biomarker for neurodegenerative and cardiovascular diseases. This work aimed to implement and validate pCASL on the dedicated MRI system within the population-based Rotterdam Study, which was installed in 2005 and for which software and hardware configurations have remained fixed. Methods: Imaging was performed on two 1.5T MRI systems (General Electric); (I) the Rotterdam Study system, and (II) a hospital-based system with a product pCASL sequence. An in-house implementation of pCASL was created on scanner I. A flow phantom and three healthy volunteers (<27 years) were scanned on both systems for validation purposes. The data of the first 30 participants (86 ± 4 years) of the Rotterdam Study undergoing pCASL scans on scanner I only were analyzed with and without partial volume correction for gray matter. Results: The validation study showed a difference in blood flow velocity, sensitivity, and spatial coefficient of variation of the perfusion-weighted signal between the two scanners, which was accounted for during post-processing. Gray matter CBF for the Rotterdam Study participants was 52.4 ± 8.2 ml/100 g/min, uncorrected for partial volume effects of gray matter. In this elderly cohort, partial volume correction for gray matter had a variable effect on measured CBF in a range of cortical and sub-cortical regions of interest. Conclusion: Regional CBF measurements are now included to investigate novel biomarkers in the Rotterdam Study. This work highlights that when it is not feasible to purchase a novel ASL sequence, an in-house implementation is valuable

    Is chloroquine chemoprophylaxis still effective to prevent low birth weight? Results of a study in Benin

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    BACKGROUND: In areas of stable transmission, malaria during pregnancy is associated with severe maternal and foetal outcomes, especially low birth weight (LBW). To prevent these complications, weekly chloroquine (CQ) chemoprophylaxis is now being replaced by intermittent preventive treatment with sulfadoxine-pyrimethamine in West Africa. The prevalence of placental malaria and its burden on LBW were assessed in Benin to evaluate the efficacy of weekly CQ chemoprophylaxis, prior to its replacement by intermittent preventive treatment. METHODS: In two maternity clinics in Ouidah, an observational study was conducted between April 2004 and April 2005. At each delivery, placental blood smears were examined for malaria infection and women were interviewed on their pregnancy history including CQ intake and dosage. CQ was measured in the urine of a sub-sample (n = 166). Multiple logistic and linear regression were used to assess factors associated with LBW and placental malaria. RESULTS: Among 1090 singleton live births, prevalence of placental malaria and LBW were 16% and 17% respectively. After adjustment, there was a non-significant association between placental malaria and LBW (adjusted OR = 1.43; P = 0.10). Multiple linear regression showed a positive association between placental malaria and decreased birth weight in primigravidae. More than 98% of the women reported regular chemoprophylaxis and CQ was detectable in 99% of urine samples. Protection from LBW was high in women reporting regular CQ prophylaxis, with a strong duration-effect relationship (test for linear trend: P < 0,001). CONCLUSION: Despite high parasite resistance and limited effect on placental malaria, a CQ chemoprophylaxis taken at adequate doses showed to be still effective in reducing LBW in Benin

    A Systematic Review of Mosquito Coils and Passive Emanators: Defining Recommendations for Spatial Repellency Testing Methodologies.

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    Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS), long lasting insecticide treated nets (LLINs) and insecticide treated materials (ITMs). PubMed, (National Centre for Biotechnology Information (NCBI), U.S. National Library of Medicine, NIH), MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words "Mosquito coils" "Mosquito emanators" and "Spatial repellents". It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose-response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP), which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control

    The angular disclination

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    Similarly to the angular dislocation introduced by Yoffe, the angular disclination is a basic configuration that is suitable for generating polygonal loops by superposition. The displacements in an unbounded elastic material are given and the generation of closed loops discussed. La disclinaison angulaire est une configuration fondamentale la plus facile à construire des disclinaisons en polygone, tout comme dans le cas de la dislocation angulaire introduite par Yoffe. Nous donnons ici les déplacements dans un milieu élastique infini et discutons la méthode de construction des disclinaisons en polygone.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42686/1/10659_2004_Article_BF00041129.pd

    Malaria and anemia prevention in pregnant women of rural Burkina Faso

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    BACKGROUND: Pregnant women are a major risk group for malaria in endemic areas. Only little information exists on the compliance of pregnant women with malaria and anaemia preventive drug regimens in the rural areas of sub-Saharan Africa (SSA). In this study, we collected information on malaria and anaemia prevention behaviour in pregnant women of rural Burkina Faso. METHODS: Cross-sectional qualitative and quantitative survey among 225 women of eight villages in rural northwestern Burkina Faso. Four of the villages had a health centre offering antenatal care (ANC) services while the other four were more than five kilometers away from a health centre. RESULTS: Overall ANC coverage (at least one visit) was 71% (95% in health centre villages vs 50% in remote villages). Malaria and anaemia were considered as the biggest problems during pregnancy in this community. ANC using women were quite satisfied with the quality of services, and compliance with malaria and anaemia prevention regimens (chloroquine and iron/folic acid) was high in this population. Knowledge on the benefit of bed nets and good nutrition was less prominent. Distance, lack of money and ignorance were the main reasons for women to not attend ANC services. CONCLUSIONS: There is an urgent need to improve access of rural SSA women to ANC services, either through increasing the number of rural health centres or establishing functioning outreach services. Moreover, alternative malaria and anaemia prevention programmes such as intermittent preventive treatment with effective antimalarials and the distribution of insecticide-treated bed nets need to become implemented on a large scale
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