40 research outputs found

    The Parity Rate of Indoor-Resting Adult Female Anopheles and Culex Mosquitoes and Their Implication in Disease Transmission in Nnamdi Azikiwe University Female Hostels Awka, South Eastern Nigeria

    Full text link
    A study on the parity rate of indoor-resting Anopheles and Culex mosquitoes and their implication in disease transmission was carried out in Nnamdi Azikiwe University female hostel between June and July 2016. The mosquitoes were sampled weekly from 24 randomly selected rooms using pyrethrum knock-down collection (P.K.C). A total of 516 mosquitoes comprising of 4 species: Anopheles Gambiae, Anopheles funestus, Culex quinquefasciatus and Culex annulioris, were collected during the study period. The mosquitoes were examined for their abdominal gradings/gonotrophic stages and dissected for parity determination. Culex quinquefasciatus (61.43%) constituted the most abundant species followed by Anopheles Gambiae (30.04%) and Anopheles funestus (7.56%) and the least being Culex annulioris (0.97%). Results showed that majority of the vector species were fed and parous and variations among the parity rates of the 4 species was significant (

    Solvent and solvation effects on reactivities and mechanisms of phospho group transfers from phosphate and phosphinate esters to nucleophiles

    Get PDF
    Organophosphorus esters fulfil many industrial, agricultural, and household roles. Nature has deployed phosphates and their related anhydrides as energy carriers and reservoirs, as constituents of genetic materials in the form of DNA and RNA, and as intermediates in key biochemical conversions. The transfer of the phosphoryl (PO3) group is thus a ubiquitous biological process that is involved in a variety of transformations at the cellular level such as bioenergy and signals transductions. Significant attention has been paid in the last seven decades to understanding the mechanisms of uncatalyzed (solution) chemistry of the phospho group transfer because of the notion that enzymes convert the dissociative transition state structures in the uncatalyzed reactions into associative ones in the biological processes. In this regard, it has also been proposed that the rate enhancements enacted by enzymes result from the desolvation of the ground state in the hydrophobic active site environments, although theoretical calculations seem to disagree with this position. As a result, some attention has been paid to the study of the effects of solvent change, from water to less polar solvents, in uncatalyzed phospho transfer reactions. Such changes have consequences on the stabilities of the ground and the transition states of reactions which affect reactivities and, sometimes, the mechanisms of reactions. This review seeks to collate and evaluate what is known about solvent effects in this domain, especially their effects on rates of reactions of different classes of organophosphorus esters. The outcome of this exercise shows that a systematized study of solvent effects needs to be undertaken to fully understand the physical organic chemistry of the transfer of phosphates and related molecules from aqueous to substantially hydrophobic environments, since significant knowledge gaps exist

    Screening for kidney disease in children on World Kidney Day in Lagos State, Nigeria

    Get PDF
    Background: Across the world, World Kidney Day (WKD) is marked yearly to increase awareness of kidney diseases. In 2016, its focus was on children for the first time. We report on a WKD screening initiative for kidney disease that was conducted in two public schools in Lagos State, Nigeria.Methods: Participants were recruited after guardians provided signed consent and older children gave assent. Baseline data were obtained which included family history of chronic diseases like sickle cell disease, hypertension, diabetes, renal disease, and the use of herbal medications. Anthropometric parameters such as height, weight and body mass index (BMI) were recorded. Investigations included urinalysis, measurement of serum creatinine and estimation of glomerular filtration rate (eGFR) using the Schwartz formula.Results: A total of 405 children were screened; there were 190 (46.9%) males and 215 females. The children were aged 2 to 17 years with a mean age of 9.1 ± 3.0 years. Over 80% of the children had normal nutritional status. Severe thinness was seen in 22 (6.8%) whereas overweight was present in 10 (3.1%). Only 1 was obese. eGFR was above 90 mL/min/1.73 m2 in 232 (94.3%) of the participants. Hypertension was present in 47 (14.4%), with the highest rate among those 0–8 years old. Proteinuria was detected in 118 (29.2%); none of the children had haematuria. Systolic hypertension, a family history of smoking and the use of herbal medications were associated with proteinuria.Conclusions: The study has highlighted a high rate of proteinuria, associated with the use of herbal medications, hypertension and a family history of smoking. Screening for renal disease in children with appropriate follow-up and timely intervention to avoid progression to end-stage renal disease is imperative

    Physical Organic Perspectives on Phospho Group Transfer fromPhosphates and Phosphinates

    No full text
    As phosphoryl transfer reactions are ubiquitous in biological chemistry, organic chemists have been very interested in the mechanisms of phosphate and phosphinate esters. Physical organic chemistry methods, including stereochemical studies, linear free energy relationships, and, most recently, heavy-atom kinetic isotope effects, have been used in the quest for mechanistic information about the chemistry of these compounds. This review summarizes what has been learned about the uncatalyzed phosphoryl transfer reactions of phosphate and phosphinate esters

    Dynamics of Classical Solutions of a Two-Stage Structured Population Model with Nonlocal Dispersal

    No full text
    We study the dynamics of classical solutions of a two-stage structured population model with nonlocal dispersal in a spatially heterogeneous environment and address the question of the persistence of the species. In particular, we show that the species’ persistence is completely determined by the sign of the principal spectrum point, λp, of the linearized system at the trivial solution: the species goes extinct if λp≤0, while it persists uniformly in space if λp>0. Sufficient conditions are provided to guarantee the existence, uniqueness, and stability of a positive steady state when the parameters are spatially heterogeneous. Furthermore, when the model parameters are spatially homogeneous, we show that the unique positive equilibrium is globally stable with respect to positive perturbations
    corecore