65 research outputs found
Knowledge, attitudes and practices (KAP) of hygiene among school children in Angolela, Ethiopia
Introduction. Poor hygiene practices and inadequate sanitary conditions play major roles in the increased burden of communi- cable diseases within developing countries. This study evaluated the KAP of hygiene among rural school children in Ethiopia and assessed the extent to which proper knowledge of hygiene was associated with personal hygiene characteristics.
Methods. This cross-sectional study was comprised of 669 students who were interviewed by trained staff. Participants were in grades 1-6 at Angolela Primary School, located in rural Ethiopia. Data consisted of hygiene and hand washing practices, knowledge about sanitation, personal hygiene characteristics, and presence of gastrointestinal parasitic infection.
Results. Approximately 52% of students were classified as having adequate knowledge of proper hygiene. Most students reported hand washing before meals (99.0%), but only 36.2% reporte
Phenolic and furanic compounds of Portuguese chestnut and French, American and Portuguese oak wood chips
Botanical species used on aging process must
be wisely and judiciously chosen, and for this selection, a
basic knowledge of the chemical composition of woods is
warranted. Aiming to contribute to extend the knowledge
of the chemical composition of several wood species useful
for enological purposes, we have focused our studies on
Portuguese chestnut and French, American and Portuguese
oak chips. The profile of low molecular weight phenolic
composition of these chips was achieved, using an optimized
extraction method based on pressurized liquid
extraction, followed by the quantification of phenolic acids,
phenolic aldehydes and furanic derivatives by high-performance
liquid chromatography (HPLC-DAD). The
identification of those compounds was also confirmed by
LC-DAD/ESI-MS. This study allowed the determination of
the low molecular phenolic composition of Portuguese
chestnut and French, American and Portuguese oak wood.
According to our results, the influence of the botanical
species seems to be more relevant than the geographic
origin of the wood species
Investigating antimalarial drug interactions of emetine dihydrochloride hydrate using CalcuSyn-based interactivity calculations
The widespread introduction of artemisinin-based combination therapy has contributed to
recent reductions in malaria mortality. Combination therapies have a range of advantages,
including synergism, toxicity reduction, and delaying the onset of resistance acquisition.
Unfortunately, antimalarial combination therapy is limited by the depleting repertoire of
effective drugs with distinct target pathways. To fast-track antimalarial drug discovery, we
have previously employed drug-repositioning to identify the anti-amoebic drug, emetine
dihydrochloride hydrate, as a potential candidate for repositioned use against malaria.
Despite its 1000-fold increase in in vitro antimalarial potency (ED50 47 nM) compared with
its anti-amoebic potency (ED50 26±32 uM), practical use of the compound has been limited
by dose-dependent toxicity (emesis and cardiotoxicity). Identification of a synergistic partner
drug would present an opportunity for dose-reduction, thus increasing the therapeutic window.
The lack of reliable and standardised methodology to enable the in vitro definition of
synergistic potential for antimalarials is a major drawback. Here we use isobologram and
combination-index data generated by CalcuSyn software analyses (Biosoft v2.1) to define
drug interactivity in an objective, automated manner. The method, based on the median
effect principle proposed by Chou and Talalay, was initially validated for antimalarial application
using the known synergistic combination (atovaquone-proguanil). The combination was
used to further understand the relationship between SYBR Green viability and cytocidal versus
cytostatic effects of drugs at higher levels of inhibition. We report here the use of the
optimised Chou Talalay method to define synergistic antimalarial drug interactivity between
emetine dihydrochloride hydrate and atovaquone. The novel findings present a potential
route to harness the nanomolar antimalarial efficacy of this affordable natural product
Phenolic and furanic compounds of Portuguese chestnut and French, American and Portuguese oak wood chips
The stellar halo of the Galaxy
Stellar halos may hold some of the best preserved fossils of the formation
history of galaxies. They are a natural product of the merging processes that
probably take place during the assembly of a galaxy, and hence may well be the
most ubiquitous component of galaxies, independently of their Hubble type. This
review focuses on our current understanding of the spatial structure, the
kinematics and chemistry of halo stars in the Milky Way. In recent years, we
have experienced a change in paradigm thanks to the discovery of large amounts
of substructure, especially in the outer halo. I discuss the implications of
the currently available observational constraints and fold them into several
possible formation scenarios. Unraveling the formation of the Galactic halo
will be possible in the near future through a combination of large wide field
photometric and spectroscopic surveys, and especially in the era of Gaia.Comment: 46 pages, 16 figures. References updated and some minor changes.
Full-resolution version available at
http://www.astro.rug.nl/~ahelmi/stellar-halo-review.pd
Onchocerciasis: The Pre-control Association between Prevalence of Palpable Nodules and Skin Microfilariae
*Background*: The prospect of eliminating onchocerciasis from Africa by mass treatment with ivermectin has been rejuvenated following recent successes in foci in Mali, Nigeria and Senegal. Elimination prospects depend strongly on local transmission conditions and therefore on pre-control infection levels. Pre-control infection levels in Africa have been mapped largely by means of nodule palpation of adult males, a relatively crude method for detecting infection. We investigated how informative pre-control nodule prevalence data are for estimating the pre-control prevalence of
Overexpression of Human and Fly Frataxins in Drosophila Provokes Deleterious Effects at Biochemical, Physiological and Developmental Levels
10 pages, 5 figures. 21779322[PubMed] PMCID: PMC3136927BACKGROUND: Friedreich's ataxia (FA), the most frequent form of inherited ataxias in the Caucasian population, is caused by a reduced expression of frataxin, a highly conserved protein. Model organisms have contributed greatly in the efforts to decipher the function of frataxin; however, the precise function of this protein remains elusive. Overexpression studies are a useful approach to investigate the mechanistic actions of frataxin; however, the existing literature reports contradictory results. To further investigate the effect of frataxin overexpression, we analyzed the consequences of overexpressing human (FXN) and fly (FH) frataxins in Drosophila.
METHODOLOGY/PRINCIPAL FINDINGS: We obtained transgenic flies that overexpressed human or fly frataxins in a general pattern and in different tissues using the UAS-GAL4 system. For both frataxins, we observed deleterious effects at the biochemical, histological and behavioral levels. Oxidative stress is a relevant factor in the frataxin overexpression phenotypes. Systemic frataxin overexpression reduces Drosophila viability and impairs the normal embryonic development of muscle and the peripheral nervous system. A reduction in the level of aconitase activity and a decrease in the level of NDUF3 were also observed in the transgenic flies that overexpressed frataxin. Frataxin overexpression in the nervous system reduces life span, impairs locomotor ability and causes brain degeneration. Frataxin aggregation and a misfolding of this protein have been shown not to be the mechanism that is responsible for the phenotypes that have been observed. Nevertheless, the expression of human frataxin rescues the aconitase activity in the fh knockdown mutant.
CONCLUSION/SIGNIFICANCE: Our results provide in vivo evidence of a functional equivalence for human and fly frataxins and indicate that the control of frataxin expression is important for treatments that aim to increase frataxin levels.This work was supported by grants from Fondo Investigaciones Sanitarias (ISCIII06- PI0677) and La Fundació la Marató TV3 (exp 101932) of Spain. JVL is supported by the European Friedreich's Ataxia Consortium for Translational Studies. SS is a recipient of a fellowship from Ministerio de Ciencia e Innovación of Spain.Peer reviewe
Are Females More Responsive to Emotional Stimuli? A Neurophysiological Study Across Arousal and Valence Dimensions
Men and women seem to process emotions and react to them differently. Yet, few neurophysiological studies have systematically investigated gender differences in emotional processing. Here, we studied gender differences using Event Related Potentials (ERPs) and Skin Conductance Responses (SCR) recorded from participants who passively viewed emotional pictures selected from the International Affective Picture System (IAPS). The arousal and valence dimension of the stimuli were manipulated orthogonally. The peak amplitude and peak latency of ERP components and SCR were analyzed separately, and the scalp topographies of significant ERP differences were documented. Females responded with enhanced negative components (N100 and N200), in comparison to males, especially to the unpleasant visual stimuli, whereas both genders responded faster to high arousing or unpleasant stimuli. Scalp topographies revealed more pronounced gender differences on central and left hemisphere areas. Our results suggest a difference in the way emotional stimuli are processed by genders: unpleasant and high arousing stimuli evoke greater ERP amplitudes in women relatively to men. It also seems that unpleasant or high arousing stimuli are temporally prioritized during visual processing by both genders
Model-based geostatistical mapping of the prevalence of onchocerca volvulus in West Africa.
Background:
The initial endemicity (pre-control prevalence) of onchocerciasis has been shown to be an important determinant of the feasibility of elimination by mass ivermectin distribution. We present the first geostatistical map of microfilarial prevalence in the former Onchocerciasis Control Programme in West Africa (OCP) before commencement of antivectorial and antiparasitic interventions.
Methods and Findings:
Pre-control microfilarial prevalence data from 737 villages across the 11 constituent countries in the OCP epidemiological database were used as ground-truth data. These 737 data points, plus a set of statistically selected environmental covariates, were used in a Bayesian model-based geostatistical (B-MBG) approach to generate a continuous surface (at pixel resolution of 5 km x 5km) of microfilarial prevalence in West Africa prior to the commencement of the OCP. Uncertainty in model predictions was measured using a suite of validation statistics, performed on bootstrap samples of held-out validation data. The mean Pearson’s correlation between observed and estimated prevalence at validation locations was 0.693; the mean prediction error (average difference between observed and estimated values) was 0.77%, and the mean absolute prediction error (average magnitude of difference between observed and estimated values) was 12.2%. Within OCP boundaries, 17.8 million people were deemed to have been at risk, 7.55 million to have been infected, and mean microfilarial prevalence to have been 45% (range: 2–90%) in 1975.
Conclusions and Significance:
This is the first map of initial onchocerciasis prevalence in West Africa using B-MBG. Important environmental predictors of infection prevalence were identified and used in a model out-performing those without spatial random effects or environmental covariates. Results may be compared with recent epidemiological mapping efforts to find areas of persisting transmission. These methods may be extended to areas where data are sparse, and may be used to help inform the feasibility of elimination with current and novel tools
Modelling Neglected Tropical Diseases diagnostics: the sensitivity of skin snips for Onchocerca volvulus in near elimination and surveillance settings
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