Evaluation of the residual efficacy and physical durability of five long-lasting insecticidal nets (LLINs) in Senegal.

BACKGROUND: The preventive and curative strategies of malaria are based on promoting the use of long-lasting insecticidal nets (LLINs) and treating confirmed cases with artemisinin-based combination therapy. These strategies have led to a sharp decline in the burden of malaria, which remains a significant public health problem in sub-Saharan countries. The objective of this study was to determine and compare the residual efficacy of LLINs recommended by the World Health Organization. METHODS: The study was conducted in six villages in two sites in Senegal located in the Sahelo-Sudanian area of the Thiès region, 70 km from Dakar and in Mbagame, a semi-urban zone in the Senegal River Valley. A census was conducted of all sleeping places in each household to be covered by LLINs. Five brands of LLIN were distributed, and every six months, retention rates, net use, maintenance, physical integrity, insecticide chemical content, and biological efficacy were examined for each type of LLIN. RESULTS: A total of 3012 LLINs were distributed in 1249 households in both sites, with an average coverage rate of 94% (95% CI 92.68-95.3). After 36 months, the average retention rate was 12.5% and this rate was respectively 20.5%, 15.1%, 10%, 7%, and 3% for Olyset Net®, Dawa Plus® 2.0, PermaNet® 2.0, NetProtect® and Life Net®, respectively. The proportion of LLINs with holes and the average number of holes per mosquito net increased significantly during each follow-up, with a large predominance of size 1 (small) holes for all types of LLINs distributed. During the three-year follow-up, bioassay mortality rates of a susceptible strain of insectary reared Anopheles coluzzii decreased in the following net types: in Dawa Plus® 2.0 (100% to 51.7%), PermaNet® 2.0 (96.6% to 83%), and Olyset Net® (96.6% to 33.3%). Mortality rates remained at 100% in Life Net® over the same time period. After 36 months, the average insecticide content per brand of LLIN decreased by 40.9% for Dawa Plus® 2.0, 31% for PermaNet® 2.0, 39.6% for NetProtect® and 51.9% for Olyset Net® and 40.1% for Life Net. CONCLUSIONS: Although some net types retained sufficient insecticidal activity, based on all durability parameters measured, none of the net types survived longer than 2 years.

Effect of Origanum vulgare Essential Oil Supplementation on the Advanced Parameters of Mobility and on the Integrity of Human Sperm DNA.

The reduced sperm mobility is one of the most important causes of male infertility. Several reports have indicated that the treatment of subnormal sperm samples with certain agents prior to artificial insemination significantly improves the fertilizing potential of sperm. We have among others some stimulants such as pentoxifylline, relaxin, prostaglandin E, and diltiazem. In our precedent work, we had tested the effect of supplementation with three essential oils, namely, sage (Salvia officinalis), oregano (Origanum vulgare), and eucalyptus (Eucalyptus globulus), on sperm cell mobility and vitality. Oregano oil had shown interesting biological properties by giving the best values of progressive mobility and vitality. In this study, we aim to verify the effect of oregano oil supplementation on the advanced parameters of mobility and on the integrity of the sperm DNA of 25 male infertile volunteers. Our results showed that oregano oil over an incubation period of 5 to 10 min of exposure significantly improves the advanced parameters of mobility, namely, curvilinear velocity (VCL), linear velocity (VSL), the mean velocity of the path (VAP), and the amplitude of the displacement (ALH). The effect of the increase in the VCL decreased the linearity (LIN), the mean line (STR), and the mean wobble (WOB). Oregano oil at 5 min had no significant effect on the DNA fragmentation index (DFI) and sperm decondensation index (SDI). However, at 10 min, it had a significant effect on both DFI and SDI. The analysis of our results showed that this plant oil rich in terpenoids and phenolic antioxidants could be a quite good in vitro additive with high potential for the world of medically assisted reproduction.

The Effect of Supplementation with Some Essential Oils on the Mobility and the Vitality of Human Sperm.

The objective of this work is to study the improvement effect of some essential oils of sage (Salvia officinalis), oregano (Origanum vulgare), and eucalyptus (eucalyptus globulus) on the physiological parameters characterizing the quality of human sperm (mobility and vitality). We find natural biomolecules to improve sperm quality to increase the chances of success of very low in vitro fertilization (IVF) that stagnate around 20%. Sperm samples were mixed with different concentrations of essential oils. The effect of these essential oils on the motility and vitality of spermatozoa has been analyzed. The mobility was determined using a Computer Assisted Sperm Analysis (CASA). In the other side, the evaluation of sperm vitality was performed by staining eosin 2% and the microscopic examination is carried out via optical microscope. A drop of sperm will be mixed with a drop of eosin solution 2%, spread between the slip and coverslip, then allowed to air dry, and examined under a microscope. A significant improvement in the mobility and vitality of human spermatozoa has been noted with oregano. Eucalyptus after 10 min of exposure also significantly improves the mobility and vitality of the spermatozoa. Sage does not improve mobility for these incubation times but significantly improves vitality.

Datasets on extinction coefficients for free space optical link survey and optimization.

Based on visibilities data recorded from 2004 to 2013, the minimum, maximum and mean values of extinction coefficients were determined and analyzed in a monthly basis, a yearly basis and also for the whole period of observation. The extinction coefficients data are obtained for the 1330 and 1550 nm optical wavelengths and may be used inter alia for range and availability analyses of optical link for different weather conditions. The data are collected in the region of Dakar, but approach and model of investigation can be reproduced for other regions in Sahel, and in the World, for optical metrology and allied fields of study.