701 research outputs found
PETROGRAPHIE DU GISEMENT DâOR DE BONIKRO, SILLON BIRIMIEN DâOUME - FETTEKRO, COTE DâIVOIRE
The Bonikro gold deposit is located in the southern part of the Oumé- FettÚkro birimian furrow. Its lithology is made of two primary rocks units; a mafic volcanic sequence in the East and a unit of volcano-sedimentary rocks in the western part. The interface of these two units is occupied by the Bonikro Shear Zone and the granodiorit. This intrusive is associated with the dykes of pegmatite and aplite, but also with volcanic giving the group of felsic rocks in the deposit. The minerals of sericite, chlorite, epidote observed in these rocks are consistent with the impacts of the greenschist facies metamorphism. Also, these lithologies are affected by a strong hydrothermal alteration due to the abundant veins of quartz, carbonate, albite, sulphide, scheelite and gold. The distribution of these aforenamed two units in the east and in the west supports the fact that the birimian has inherited the ancient valley. The various volcanic rocks are linked to the birimian volcanism, when the pyroclastites imply that this volcanism has undergone a possible period of explosive character
The PDE4 inhibitor rolipram reverses object memory impairment induced by acute tryptophan depletion in the rat
The selective type IV phosphodiesterase inhibitor, rolipram, has been shown to improve long-term memory and can reverse the cholinergic deficit caused by scopolamine. However, the underlying mechanisms of action of rolipram remain obscure. The present study investigates the effect of rolipram in a serotonergic-deficit model of acute tryptophan depletion (ATD). In addition, the levels of plasma tryptophan (TRP) were compared to object recognition performance. The experiments were conducted using male Wistar rats. The time-dependent effect of ATD treatment (a gelatin-based protein mixture) on plasma TRP levels (0, 1, 3, and 6 h after injection) and object recognition task (ORT) performance (0.5, 1, 3, and 6 h after ATD treatment) was examined. The effect of rolipram (0, 0.01, 0.03, and 0.1 mg/kg, i.p.) was tested in the condition in which ATD induced a clear memory deficit. ATD significantly lowered the plasma TRP ratio (TRP/Sigma large neutral amino acid) with a maximum of 48%, approximately 1 h after administration. Furthermore, ATD impairs ORT performance when administered 3 h before testing. Rolipram (0.1 mg/kg) reversed the memory deficit induced by ATD in a dose-dependent manner. On the basis of previous studies and the ability to reverse a serotonergic deficit, we suggest that rolipram may act through elevation of cyclic adenosine monophosphate levels and subsequent increase in neurotransmitter release
Microplastic emissions from disposable type I and FFP2 face masks used in the Netherlands:An exploration for further research and emission mitigation measures
PETROGRAPHIE DU GISEMENT DâOR DE BONIKRO, SILLON BIRIMIEN DâOUME - FETTEKRO, COTE DâIVOIRE
The Bonikro gold deposit is located in the southern part of the Oumé- FettÚkro birimian furrow. Its lithology is made of two primary rocks units; a mafic volcanic sequence in the East and a unit of volcano-sedimentary rocks in the western part. The interface of these two units is occupied by the Bonikro Shear Zone and the granodiorit. This intrusive is associated with the dykes of pegmatite and aplite, but also with volcanic giving the group of felsic rocks in the deposit. The minerals of sericite, chlorite, epidote observed in these rocks are consistent with the impacts of the greenschist facies metamorphism. Also, these lithologies are affected by a strong hydrothermal alteration due to the abundant veins of quartz, carbonate, albite, sulphide, scheelite and gold. The distribution of these aforenamed two units in the east and in the west supports the fact that the birimian has inherited the ancient valley. The various volcanic rocks are linked to the birimian volcanism, when the pyroclastites imply that this volcanism has undergone a possible period of explosive character
Affordances and limitations of learning analytics for computer-assisted language learning: a case study of the VITAL project
Learning analytics (LA) has emerged as a field that offers promising new ways to support failing or weaker students, prevent drop-out and aid retention. However, other research suggests that large datasets of learner activity can be used to understand online learning behaviour and improve pedagogy. While the use of LA in language learning has received little attention to date, available research suggests that understanding language learner behaviour could provide valuable insights into task design for instructors and materials designers, as well as help students with effective learning strategies and personalised learning pathways. This paper first discusses previous research in the field of language learning and teaching based on learner tracking and the specific affordances of LA for CALL, as well as its inherent limitations and challenges. The second part of the paper analyses data arising from the European Commission (EC) funded VITAL project that adopted a bottom-up pedagogical approach to LA and implemented learner activity tracking in different blended or distance learning settings. Referring to data arising from 285 undergraduate students on a Business French course at Hasselt University which used a flipped classroom design, statistical and process-mining techniques were applied to map and visualise actual uses of online learning resources over the course of one semester.
Results suggested that most students planned their self-study sessions in accordance with the flipped classroom design, both in terms of their timing of online activity and selection of contents. Other metrics measuring active online engagement â a crucial component of successful flipped learning - indicated significant differences between successful and non-successful students. Meaningful learner patterns were revealed in the data, visualising studentsâ paths through the online learning environment and uses of the different activity types. The research implied that valuable insights for instructors, course designers and students can be acquired based on the tracking and analysis of language learner data and the use of visualisation and process-mining tools
The efficacy of resveratrol in controlling hypertension: study protocol for a randomized, crossover, double-blinded, placebo-controlled trial
Abstract
Background: Hypertension is a global health concern for which novel treatment strategies are necessary. The aim
of this study is to evaluate the efficacy of resveratrol (trans-3, 5, 4âČ-trihydroxystilbene, a polyphenol present in
grapes) in controlling blood pressure in participants diagnosed with prehypertension and stage 1 hypertension.
Methods/design: In a randomized, crossover, double-blinded, placebo-controlled study, 50 participants with
prehypertension (diastolic blood pressure and systolic blood pressure, 80â89 mmHg and 120â139 mmHg, respectively)
and 50 participants with stage 1 hypertension (diastolic and systolic, 90â99 mmHg and 140â159 mmHg, respectively)
will be assigned to receive resveratrol (99 % pure, from Biotivia Longevity Bioceuticals LLC Company, USA, in 500 mg
capsules, twice daily for 4 weeks, orally) or placebo (500 mg neutral microcellulose capsules, twice daily for 4 weeks) in
a 2 Ă 2 crossover design (4 weeks treatmentâ4 weeks washoutâ4 weeks treatment). The blood pressure of each
participant will be recorded (a mean of two times within a 15-minute interval) every week during the study. The
participants in the prehypertensive group will not receive any medication, while those in the stage 1 hypertensive
group will continue to receive their routine medications during the study. Blood samples will be taken from all groups
and examined for various biochemical parameters.
Discussion: This trial will help to establish whether resveratrol is an effective antihypertensive agent in prehypertensive
and stage 1-hypertensive patients. The trial outcome will provide novel insight into the clinical efficacy of resveratrol
and provide valuable information for conducting future clinical studies with resveratrol.
Trial registration: Iranian Registry of Clinical Trials, IRCT201407078129N7. Registered on 15 August 2014.
Keywords: Resveratrol, Hypertension, Blood pressure, Polypheno
Measuring personal recovery in people with a psychotic disorder based on CHIME:A comparison of three validated measures
Living well in spite of residual symptoms of mental illness is measured with the construct of personal recovery. The CHIME framework might be suitable to evaluate personal recovery measures and guide instrument choice. Three validated measures were evaluated in Dutch patients with a psychotic disorder (NÂ =Â 52). We compared the Recovery Assessment Scale (RAS), the Mental Health Recovery Measure (MHRM), and the Netherlands Empowerment List (NEL). The measures were assessed on six criteria: content validity (based on CHIME), convergent validity with a social support measure, internal consistency, floor and ceiling effects, item interpretability, and ease of administration. The MHRM scored high on content validity with a balanced distribution of items covering the CHIME framework. The MHRM and the NEL showed moderate convergent validity with social support. In all three measures, internal consistency was moderate and floor and ceiling effects were absent. The NEL scores demonstrated a high degree of item interpretability. Ease of administration was moderate for all three measures. Finally, the CHIME framework demonstrated good utility as a framework in guiding instrument choice and evaluation of personal recovery measures. The MHRM showed the best overall result. However, differences between measures were minimal. Generalization of the results is limited by cultural and linguistic factors in the assessment for the subjective measures (i.e. content validity and item interpretability). The broad and multidimensional construct of personal recovery might lead to ambiguous interpretations. Scientific consensus on a well-defined personal recovery construct is needed
25-Hydroxyvitamin D Threshold for the Effects of Vitamin D Supplements on Bone Density:Secondary Analysis of a Randomized Controlled Trial
Most trials of vitamin D supplementation have shown no benefits on bone density (BMD), though severe vitamin D deficiency causes osteomalacia which is associated with profound BMD deficits. Recently, the ViDA-BMD study from New Zealand demonstrated a threshold of baseline 25-hydroxyvitamin D (30 nmol/L) below which vitamin D supplementation did benefit BMD. We have now re-examined data from a similar trial in Aberdeen to determine whether a baseline 25-hydroxyvitamin D threshold of 30 nmol/L is also observed in that database. The Aberdeen study recruited 305 postmenopausal women in late winter and randomized them to receive placebo, vitamin D 400 IU/day or vitamin D 1000 IU/day over one year. As previously reported, BMD loss at the hip was reduced by vitamin D 1000 IU/day only, and there was no significant treatment effect of either dose at the lumbar spine. In the present analysis, when the trial participants were grouped according to whether their baseline 25-hydroxyvitamin D was â€30 nmol/L or above this threshold, significant treatment effects were apparent at both the spine and hip in those with baseline 25-hydroxyvitamin D â€30 nmol/L, but no significant effects were apparent in those with baseline 25-hydroxyvitamin D above this level. There was evidence of a similar threshold for effects on parathyroid hormone, but no groups showed changes in bone turnover markers during the study. It is concluded that vitamin D supplements only increase bone density in adults with nadir 25-hydroxyvitamin D â€30 nmol/L. This moves us further towards a trial-based definition of vitamin D deficiency in adults with adequate calcium intakes, and suggests that supplement use should be targeted accordingly. Future trials of vitamin D supplementation should focus on individuals with 25-hydroxyvitamin D concentrations in this range
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