Open Access Research Paper

The human central nervous system (CNS) infections remain the leading cause of intensified morbidity and mortality rates around the world. Vanquish the barriers that protect the brain from pathogens is a prerequisite to develop meningitis. The commonest pathogens, pneumococcus, meningococcus, E. coli, H. influenzae are main causative agents in children and adults; are associated with high morbidity and mortality. Bacteria have evolved a variety of different strategies for breaching the blood–brain barrier (BBB), evade the immune system and enter CNS. For this purpose, they use a variety of different virulence factors, allowing them to adhere to and overcome these barriers. These virulence factors arbitrate adhesion host cell invasion, intracellular survival, host cell signaling and induction of inflammation. The CNS will ultimately be invaded by the bacteria, causing inflammation of meninges, increased permeability of BBB, and pleocytosis in cerebrospinal fluid (CSF) as well as nervous tissue infiltration. Some of these mechanisms are different, but others are shared by some pathogens. Supplementary understanding of these processes, especially, differences between the blood-brain barrier and the blood-cerebrospinal fluid barrier, and Virulence factors used by pathogens are still required.

Terrestrial small mammals play important ecological roles in tropical ecosystems. They are regularly used to measure the level of habitat disturbance. This study aimed to determine the impacts of human activities on the species composition and relative abundance of terrestrial small mammal communities in Man region. Four types of habitats, including a relic forest, a fallow, rubber and coffee plantations, were sampled using Sherman live traps. With a trapping effort of 2,800 trap-nights, 132 individuals of terrestrial small mammals were collected. These specimens belong to seven species of Muridae family Grammomys buntingi, Hylomyscus simus, Lophuromys sikapusi, Malacomys edwardsi, Mus muscoloides, Mus setulosus and Praomys rostratus and one species of Soricidae family, Crocidura olivieri. The relic forest and rubber plantation recorded the highest species richness with 7 species each. The lower species richness was obtained in a coffee plantation with 4 species. In the relic forest, Crocidura olivieri and Malacomys edwardsi were the most abundant (AR = 22.92%) species. Crocidura olivieri also dominated in the fallow (RA = 26.83%). Mus musculoides (RA = 48%) and Mus setulosus (RA = 27.79%) were dominant in rubber and coffee plantations, respectively. The higher Shannon-Wiener Index was obtained in the relic forest (H’= 1.77) and the lower in the coffee plantation (H’ = 1.35). Sorensen’s similarity coefficient showed great similarity between the species composition of the relic forest and the rubber plantation.

The Egyptian cotton leafworm Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae) is among the serious cabbage pests in tropical countries. It can lead an intensive chemical insecticides use in market gardening perimeters. Alternative control methods such as biological control are necessary for the integrated management of this pest. The laboratory rearing of S. littoralis larvae sampled in the cabbage fields has been undertaken and the presence of parasitoids has been noticed. The population dynamic of S. littoralis larvae and these parasitoids has been studied in two market gardening perimeters on two crop cycles. The parasitoids of S. littoralis larvae are Apanteles sp, the hymenopterans belonging to the Braconids family, and the Microgastrin subfamily. Strong populations of Apanteles sp. involve weak populations of S. littoralis and weak populations of Apanteles sp. involve strong populations of S. littoralis. However, the correlations between Apanteles sp. adult’s number and S. littoralis larvae per ten plants are not significant for the crop cycles in all the sites. These parasitoids can be nevertheless taken to account for the integrated management program of S. littoralis. Identification of this insect up to the species could be undertaken for future studies.

The main objective focused on the economic implications of forest products utilization on respondents. Sampling technique adopted was multi-stage sampling. Well-structured questionnaires were adopted for data collection and data analysis was done using chi-square test and descriptive statistics. Most respondents were aged and aware about forest product utilization activities in the studied area. Forest were far away five to six kilometer from rural households as results of deforestation. Timber and firewood were the main forest products. The mean annual income, food and medicinal plants for ailment treatment from non-forest products were decreasing tremendously while erosion and land degradation were on the increase. The economic impacts of forest product utilization were severe with adverse economic effects on rural households. The three null tested hypotheses were rejected. The study recommends that forest protection policies and laws should be enacted followed by strict compliance.

Kenya lost over 98% of its black rhinoceros (Diceros bicornis michaeli) between the 1960s and 1990s, leaving a mere 400 animals by 1993 isolated in small populations. The population is currently on a recovery path and currently stands at over 600 animals found in small isolated subpopulations, each of less than 100 animals. Differential evolutionary selection pressures are expected to apply in such isolated subpopulation, and may drive them into separate ecological evolutionary units. The aim of this study was to examine the spatial genetic structuring and diversity of mitochondrial DNA in the Kenyan black rhinoceros. This study was motivated by the fact that currently, Kenya Wildlife Service (KWS) black rhino conservation postulates that the Kenyan black rhinoceros exists in two main subpopulation referred to as the lowland and montane populations based on exposure to tsetse fly infestation; present in lowlands but absent in montane ecosystem. This study examined the Kenyan black rhinoceros mtDNA control region genetic diversity and its spatial structuring in Kenyan subpopulations. Different hypothesized subpopulation structuring scenarios were examined; including the lowland and montane conservation units. Genetic information was obtained from 408bp mitochondrial control region sequence from 170 individuals. Both model based and standard methods were used to examine the data. The sample comprised 16 maternal lineages, moderate haplotype diversity (0.73±0.137) and low nucleotide diversity (0.007±0.003). The geographic and altitudinal distribution of haplotypes was not phylogeographically structured. This level of genetic diversity and structuring in the Kenyan black rhinoceros is consistent with their demographic population history of a recent drastic population bottleneck and slow recovery. Findings of this study imply that substantial levels of genetic diversity still exist within the Kenyan black rhinoceros gene pool. The hypothesis of lowland and montane population units is not supported from a genetic perspective. Management strategies that involve translocation among populations at a rate of at least one breeding migration per generation are therefore advocated in order to control any further loss in genetic diversity due to drift and/or inbreeding.

The Egyptian cotton leafworm Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae) is among the serious cabbage pests in tropical countries. It can lead an intensive chemical insecticides use in market gardening perimeters. Alternative control methods such as biological control are necessary for the integrated management of this pest. The laboratory rearing of S. littoralis larvae sampled in the cabbage fields has been undertaken and the presence of parasitoids has been noticed. The population dynamic of S. littoralis larvae and these parasitoids has been studied in two market gardening perimeters on two crop cycles. The parasitoids of S. littoralis larvae are Apanteles sp, the hymenopterans belonging to the Braconids family, and the Microgastrin subfamily. Strong populations of Apanteles sp. involve weak populations of S. littoralis and weak populations of Apanteles sp. involve strong populations of S. littoralis. However, the correlations between Apanteles sp. adult’s number and S. littoralis larvae per ten plants are not significant for the crop cycles in all the sites. These parasitoids can be nevertheless taken to account for the integrated management program of S. littoralis. Identification of this insect up to the species could be undertaken for future studies.

The rejection of untreated waste water in the nature decreases groundwater quality. Waste water treatment plants like activated sludge plant and stabilization pond plant built in Benin show their limits. Due to these problems, reed beds have to be experimented to bring a durable solution to waste water treatment problems in Benin. Compare to activated sludge plant and to stabilization pond plant, reed beds are the cheapest based on the technical and economical point of view. On addition to that, reed beds are easy to build and to maintain. The experiment plant is composed of four basins. The first basin is unplanted. The second basin is planted with Echinochloa pyramidalis. The third basin is planted with Panicum maximum and the last basin is planted with Typha domingensis. Each basin is a 1 m3 tank with drilled drain pipes. Three differentl ayers of gravel have been put on drilled drain pipes. Treated water analysis showed that the Typha domingensis basin has the best purfiying performances with final concentrations : 0 mg/L ; 21,10 mg/L ; 10 mg/L ; 0 mg/L et 12,20 mg/L respectively for TSS, COD, BOD5, TKN and TP. These final concentrations reached the discharge standards for municipal wastewater treatment plant in Benin. Consequently, Typha domingensis beds can be popularized by the beninese government to solve waste water treatment problems.

Dissolution is the rate-limiting step for the absorption of drugs in class II of the Biopharmaceutics Classification System (BCS) resulting in poor bioavailability. This present study was aimed at determining the outcome of in situ micronization technique on the dissolution and solubility profiles of paracetamol. Six formulations of paracetamol microcrystals were produced by the solvent change method using HPMC and PVP K30 as stabilizing agents. The solubility, percentage drug content, and dissolution patterns of the produced microcrystals were all tested. The study revealed that paracetamol solubility was increased up to 5-fold in the PVP K30 stabilized paracetamol microcrystal and a 4.5-fold increase for HPMC stabilized paracetamol microcrystal. The time course of dissolution was improved significantly from 0.6%/min for plain paracetamol to 1.1%/min and 1.2%/min for HPMC and PVP K30 stabilized paracetamol microcrystal respectively. Formulation P6, with 0.08 g of PVP K30 as stabilizing agents and anti-solvent to solvent ratio of 1:6 was the optimized formulation having a 5-fold solubility increase, 98.3% content of active and 95.32% drug release in 60 minutes. The solvent change approach of the in situ micronization technique could be used for the augmentation of solubility and dissolution of paracetamol.

Sexual maturity size, gonado-somatic index, sex ratio and fecundity were studied during four seasons, from January to December 2020, in Hoplobatrachus occipitalis which lives in the water of drainage furrows of banana plantations treated with phytosanitary products in the locality of Dabou. Our results reveal that the sizes of first sexual maturity in females and males of this species are 91.39 mm and 85.62 mm, respectively. Females reproduce during the main rainy season. The sex ratio is in favor of females (1:1.18) except during the main rainy season. Regarding fecundity, female gonads of this frog contain 2413 to 151 eggs with an average of 642 ± 541 and an oocyte diameter of 0.20 ± 0.03 mm. In this habitat, this frog has single oviposition (The coefficient of variation is 17.29).