Assessment of heavy metal concentrations as indicator of pollution in Clarias gariepinus (African catfish) of Warwade reservoir, Dutse, Jigawa State-Nigeria

Pollution status of Warwade reservoir was assessed using heavy metals bioaccumulation in water, gills and liver samples of C. gariepinus between July and December, 2019. Heavy metals analyses were carried out using microwave plasma atomic spectroscopy (MP-AES). Water and fish were sampled fortnightly from the three sites coded as upstream (A), midstream (B) and downstream (C) between 7:00 – 7:30am for period of six months. The results revealed that heavy metal concentrations in water followed the order: Cr (2.15mg/L)>Cu (1.40mg/L) > Pb (0.89mg/L)> Cd (0.68mg/L). Bioaccumulation Factor (BAF) of heavy metal concentration in water decreased in the order of Cr > Pb > Cu >Cd. In the fish organs, gills had the highest value of Cr, followed by Pb, Cu and Cd recorded the lowest. The BAF in liver tissues decreased in the order of Cu > Pb > Cr >Cd. BAF for Cu was highest in liver tissue (2.90) while the lowest was obtained in the gills (1.04). Lead (Pb) had its highest value in liver (2.16) and the lowest value (1.33) was obtained in the gill. BAF in Cr had its highest value of 2.15 in water and the lowest was obtained in the gills. Heavy metals bioaccumulation differed significantly (p<0.05) between the sampling sites and seasons with the exception of cadmium which did not differed significantly (p>0.05). It can be deduced that heavy metals bioaccumulation in the fish tissue is attributed to the influx of chemicals into the reservoir as a result of agrochemicals input among other anthropogenic activities. It is recommended that indiscriminate release of the xenobiotic compounds should be minimized in order to avert degradation of the reservoir in the long run. Intervention by appropriate authorities to curtail the effects of heavy metals on fish species among other important biota is recommended

Characteristics of fresh and frozen-thawed Uda ram semen extended with Oviplus®, egg yolk and coconut milk

Semen characteristics of Uda sheep and the effects of the egg yolk and coconut milkbased extenders on the quality of semen preserved at 4 oC and -196 oC were evaluated. Semen was collected from six Uda rams using an electro-ejaculator twice a week for ten weeks. Fresh semen samples were pooled and analyzed macroscopically and microscopically. The pooled semen was divided into 2 aliquots. One aliquot was extended in OviPlus® and egg yolk. The second aliquot was extended with OviPlus® and coconut milk. Each of the aliquots was further subdivided into 2 parts and evaluated microscopically. One part was chilled at 4 oC and evaluated for the same parameters after extension at 24, 48 and 72 hours. Second part was loaded into 0.25 ml plastic straws for cryopreservation at -196 ℃ and analyzed after 24 hours. The post thaw spermatozoa motility, livability and morphological abnormalities were determined at 24, 48 and 72 hours. The motility and concentration of freshly collected Uda semen were 81.7 ± 1.7 % and 3.2 ± 0.3 ×109/ml respectively. After extension, the motility decreased significantly (P < 0.05) from 82 % at 3 hours to 17 % at 72. The percentage live spermatozoa of the chilled semen did not differ significantly (P > 0.05) between the two extenders. Post thaw spermatozoa motility and livability were significantly (P < 0.05) reduced. There were significant differences (P < 0.05) between the post-thaw proportions of morphological abnormalities, between semen preserved at 4 oC and the frozen-thawed semen. In conclusion, semen motility, livability, and morphological abnormalities of Uda ram are equally preserved in coconut milk and egg yolk-based extenders at 4 oC up to 24 hours post extension. However, semen motility and livability were significantly reduced in the Uda semen earlier cryopreserved at -196 oC after thawing

The acceleration of the universe and the physics behind it

Using a general classification of dark enegy models in four classes, we discuss the complementarity of cosmological observations to tackle down the physics beyond the acceleration of our universe. We discuss the tests distinguishing the four classes and then focus on the dynamics of the perturbations in the Newtonian regime. We also exhibit explicitely models that have identical predictions for a subset of observations.Comment: 18 pages, 18 figure

Dark Energy from structure: a status report

The effective evolution of an inhomogeneous universe model in any theory of gravitation may be described in terms of spatially averaged variables. In Einstein's theory, restricting attention to scalar variables, this evolution can be modeled by solutions of a set of Friedmann equations for an effective volume scale factor, with matter and backreaction source terms. The latter can be represented by an effective scalar field (`morphon field') modeling Dark Energy. The present work provides an overview over the Dark Energy debate in connection with the impact of inhomogeneities, and formulates strategies for a comprehensive quantitative evaluation of backreaction effects both in theoretical and observational cosmology. We recall the basic steps of a description of backreaction effects in relativistic cosmology that lead to refurnishing the standard cosmological equations, but also lay down a number of challenges and unresolved issues in connection with their observational interpretation. The present status of this subject is intermediate: we have a good qualitative understanding of backreaction effects pointing to a global instability of the standard model of cosmology; exact solutions and perturbative results modeling this instability lie in the right sector to explain Dark Energy from inhomogeneities. It is fair to say that, even if backreaction effects turn out to be less important than anticipated by some researchers, the concordance high-precision cosmology, the architecture of current N-body simulations, as well as standard perturbative approaches may all fall short in correctly describing the Late Universe.Comment: Invited Review for a special Gen. Rel. Grav. issue on Dark Energy, 59 pages, 2 figures; matches published versio

Neonatal sepsis and mortality in low-income and middle-income countries from a facility-based birth cohort: an international multisite prospective observational study

Background Neonatal sepsis is a primary cause of neonatal mortality and is an urgent global health concern, especially within low-income and middle-income countries (LMICs), where 99% of global neonatal mortality occurs. The aims of this study were to determine the incidence and associations with neonatal sepsis and all-cause mortality in facility-born neonates in LMICs. Methods The Burden of Antibiotic Resistance in Neonates from Developing Societies (BARNARDS) study recruited mothers and their neonates into a prospective observational cohort study across 12 clinical sites from Bangladesh, Ethiopia, India, Pakistan, Nigeria, Rwanda, and South Africa. Data for sepsis-associated factors in the four domains of health care, maternal, birth and neonatal, and living environment were collected for all mothers and neonates enrolled. Primary outcomes were clinically suspected sepsis, laboratory-confirmed sepsis, and all-cause mortality in neonates during the first 60 days of life. Incidence proportion of livebirths for clinically suspected sepsis and laboratory-confirmed sepsis and incidence rate per 1000 neonate-days for all-cause mortality were calculated. Modified Poisson regression was used to investigate factors associated with neonatal sepsis and parametric survival models for factors associated with all-cause mortality. Findings Between Nov 12, 2015 and Feb 1, 2018, 29 483 mothers and 30 557 neonates were enrolled. The incidence of clinically suspected sepsis was 166·0 (95% CI 97·69–234·24) per 1000 livebirths, laboratory-confirmed sepsis was 46·9 (19·04–74·79) per 1000 livebirths, and all-cause mortality was 0·83 (0·37–2·00) per 1000 neonate-days. Maternal hypertension, previous maternal hospitalisation within 12 months, average or higher monthly household income, ward size (>11 beds), ward type (neonatal), living in a rural environment, preterm birth, perinatal asphyxia, and multiple births were associated with an increased risk of clinically suspected sepsis, laboratory-confirmed sepsis, and all-cause mortality. The majority (881 [72·5%] of 1215) of laboratory-confirmed sepsis cases occurred within the first 3 days of life. Interpretation Findings from this study highlight the substantial proportion of neonates who develop neonatal sepsis, and the high mortality rates among neonates with sepsis in LMICs. More efficient and effective identification of neonatal sepsis is needed to target interventions to reduce its incidence and subsequent mortality in LMICs. Funding Bill & Melinda Gates Foundation

Peasant differentiation and politics in rural Kano 1900-1987

Available from British Library Document Supply Centre- DSC:D170840 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Cocoa farming and income diversification in south-western Nigeria

This working paper provides research findings emanating from the De-Agrarianisation and Rural Employment (DARE) Research Programme, coordinated by the African Studies Centre, Leiden. The aim of the Programme was to examine, from a multidisciplinary perspective, the changes in size and significance of the peasant population in sub-Saharan African countries and to draw attention to the new labour patterns and unfolding rural-urban relations now taking place. This paper focuses on Nigeria and chronicles the patterns of long-term diversification that are observable in the cocoa farming community of Alade in Idanre Local Government Area of Ondo State. After some historical background information on cocoa cultivation and government policies up to 1970, when Nigeria began to experience its oil boom, it looks at the impact of the oil boom of the 1970s and the Structural Adjustment Programme (SAP), introduced in 1986, on cocoa farming before turning to the situation of household production and reproduction in the aftermath of SAP, and the internal dynamics of Alade households. Finally, it looks at the extent and trends of diversification of livelihood strategies within the farming community. The conclusion is that SAP has led to a revival of cocoa farming in Nigeria and that farming households have responded to new opportunities opened up to them by adjusting their use of household resources. However, the benefits of this revival have not been evenly spread.ASC – Publicaties niet-programma gebonde

The use of hydrogenated Schiff base ligands in the synthesis of multi-metallic compounds

The synthetic utility of tris-((2-hydroxybenzyl)-aminoethyl)amine (H6TrenSal) and tris-((2-hydroxy-5-bromobenzyl)-aminoethyl)amine (H6Tren5BrSal) are investigated. A range of monomeric complexes with general formula [(H6TrenSal) M][NO3] with nickel, copper and zinc are reported and crystallographically analysed. Nickel adopts three motifs which are different to that observed for copper and zinc. The use of these species as platforms for the synthesis of more complex systems in conjunction with the lanthanoids are explored. Copper and zinc do not follow a similar reaction pathway to nickel. While nickel forms the expected trimetallic motif [{(TrenSal)Ni}(2)Ln(HOMe)](+), copper forms a copper trimetallic motif. In contrast to both nickel and copper, reactions with [(H6TrenSal)Zn](+) produce lanthanoid based products namely [(H6Tren5BrSal)Gd(NO3)(3)] and [{(H6TrenSal)Ce}(2)-mu(2)-O-2]