TYPOLOGY AND POLICY FOR SMALL FARMS

Agricultural and Food Policy,

Comparative effects of pre-gestational doses of clomiphene citrate versus letrozole on the heart of developing wistar rats

Drug-induced ovulation is a therapy that allows women to ovulate and have the chance of conceiving. This therapy is used either in women  with irregular ovulation or in patients undergoing In-vitro fertilization cycle to maximize egg production. The goal of drug-induced ovulation is to stimulate the ovaries to produce a single mature follicle and allow fertilization and pregnancy to occur. The drugs commonly used are clomiphene citrate and letrozole. There are indications that these drugs, when used prenatally, could interfere with the normal development of foetal hearts, though; there is a paucity of data on the lethal effects of drug-induced ovulation on the neonatal heart, particularly the left ventricle and ventricular septum. Forty-five adult female Wistar rats that weighed between 140-160g were used for the experiment. They were subdivided into three groups of 15 animals each. A vaginal smear was carried out to further divide the experimental animals based on their  oestrous phases. A one-time dose of clomiphene citrate (clomid) was administered at 0.5mg/kg bodyweight, to one of the experimental groups, during the diestrous phase. The other experimental group received Letrozole at  0.025mg/kg bodyweight while the control group received normal feed and water liberally. Mating was done a day after administration of these drugs. Pups were sacrificed on postnatal day 21, the hearts of the pups were dissected out and processed for histological analysis. The result showed that the pups whose mothers received clomid had the lowest heart weights compared to the letrozole and control groups. The left ventricular wall thickness was greater in the Letrozole group and the level of necrosis was observed to be greater in the clomid group as compared to the other groups. These findings show that both clomid and letrozole have some effects on the hearts of the developing wistar rats

Child Work, Child Schooling And Educational Achievement: An Empirical Evidence For Nigeria

As a result of the growing international concern about child labour, child work and the effects on the welfare and future of these children, the practices are now being questioned in Nigeria. The recent perception of child labour and child work as a problem stems from the belief, and finding on investigations that involvement of children in economic activities outside the home is injurious to the children’s intellectual and physical growth. According to Oloko (1996) working is believed to expose children to physical danger, sexual abuse and other forms of harassment. It is also believed that work prevents children from doing well in school with the resultant risk of condemning them to low wage income in the future (Falayajo, Makoju, Okebukola, Onuga & Olubodun, 1997 and Ray, 2000). An International Labour Organisation (ILO) study quoted by Beguile and Boyden (1988) even went further to suggest that child labour may contribute to adult unemployment. This may be so since children could become substitute workers at cheaper wage rates

Effect of Alloying Element on the Integrity and Functionality of Aluminium-Based Alloy

Aluminum alloy are gaining huge industrial significance because of their outstanding combination of mechanical, physical and tribological properties over the base metal. Alloying elements are selected based on their individual properties as they impact on the structure and performance characteristics. The choice of this modifier affects the materials integrity in service resulting to improved corrosion, tribological and mechanical behavior. Hence, the need to understand typically the exact inoculants that could relatively impact on the low strength, unstable mechanical properties is envisage with the help of liquid stir casting technique. In this contribution, sufficient knowledge on Al alloy produced by stir casting will be reviewed with close attention on how the structural properties impact on the mechanical performance

Estudos de heavy metal e diversidade genética em três populações de Snail (Achatina achatina Linnaeus, 1758) do sudoeste da Nigéria

Environmental pollutants may often alter the genetic components of natural populations. In this study, heavy metals and genetic diversity in land snail (Achatina achatina) from three populations of south-western Nigeria were investigated, using the Atomic Absorption Spectrometry and DNA Sequencing technology respectively. Metal analysis revealed that the snails accumulated lead (Pb) and nickel (Ni) in high concentrations in two of the three states, while cadmium (Cd) was the least detected. Editing and alignment of the sequences of all snail accessions generated a range of 384bp to 419 bp. Analysis of Molecular Variance (AMOVA) in all 18 accessions was low at only 16%. The query coverage (QC) ranged between 96% and 100%, with 14 (77.8%) of the 18 accessions showing 100% identity. Pairwise comparison of the accessions studied also showed a high genetic similarity. The unweighted pair group method with arithmetic mean (UPGMA) generated two main clusters. Cluster I was unique and contain one sample (AaOy06) while the other cluster are very closely related and can be further sub-divided into sub-clusters. The similarity index of between the clusters is 0.5357. The close similarity among the accessions may be due to the geographical proximity of the three states. The uniqueness of accession AaOy06 in comparison to other accessions might be due to the negative influence of heavy metal, particularly lead. The determination of evolutionary relationships among snail populations may be useful towards the breeding efforts of the species in Nigeria

Equal Channel Angular Extrusion Characteristics on Mechanical Behavior of Aluminum Alloy

Materials strengthened by conventional methods such as strain hardening, solute additions, precipitation and grain size refinement are often adopted in industrial processes. But there is limitation to the amount of deformation that these conventional methods can impact to a material. This study focused on the review of major mechanical properties of aluminum alloys in the presence of an ultrafine grain size into polycrystalline materials by subjecting the metal to an intense plastic straining through simple shear without any corresponding change in the cross-sectional dimensions of the sample. The effect of the heavy strain rate on the microstructure of aluminum alloys was in refinement of the coarse grains into ultrafine grain size by introducing a high density of dislocations and subsequently re-arranging the dislocations to form an array of grain boundaries. Hence, this investigation is aimed at gathering contributions on the influence of equal channel angular extrusion toward improving the mechanical properties of the aluminum alloys through intense plastic strain

In-situ formation characteristic, tribological characterization and anti-corrosion properties of quaternary composites films

Improvements of wear and corrosion properties are essential characteristic in engineering application. A study was made on the structure, electro-oxidation and properties of fabricated Z