52 research outputs found

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

    Get PDF
    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

    Diversity, religious pluralism, and democracy

    Get PDF
    Global Challenges (FGGA

    The acceleration of the universe and the physics behind it

    Full text link
    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

    Full text link
    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

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

    Get PDF
    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

    Chemosensitivity of U251 cells to the co-treatment of D-penicillamine and copper: Possible implications on wilson disease patients

    Get PDF
    D-Penicillamine (PA), a copper chelator, andone of the recommendeddrugs for treatment of Wilson disease (WD) has been reported to worsen the symptoms of patients with neurologic presentations. However, the cause of this paradoxical response has not been fully elucidated and requires further investigations. Accordingly, we have studied the in vitro effect of Copper (Cu) and/or PAtreatment on human glioblastoma U251 cells as an in vitro model of Cu cytotoxicity. Treatment of U251 cells with either Cu or PA exerted no significant effect on their morphology, viability or ROS level. In contrast, co-treatment with Cu-PA caused a decrease in viability, altered glutathione and ceruloplasmin expression coupled with marked increase in ROS; depolarization of mitochondrial membrane potential; and an increase in Sub G0 phase; along with alpha-Fodrin proteolysis. These findings along with the absence of LDH release in these assays, suggest that combined Cu-PA exposure induced apoptosis in U251 cells. In addition, pre-/or co-treatment with antioxidants showed a protective effect, with catalase being more effective than N-acetyl cysteine or trolox in restoring viability and reducing generated ROS levels. By comparison, a similar analysis using other cell lines showed that rat PC12 cells were resistant to Cu and/or PA treatment, while the neuroblastoma cell line SH-SY5Y was sensitive to either compound alone, resulting in decreased viability and increased ROS level. Taken together, this study shows that glioblastoma U251 cells provide a model for Cu-PA cytotoxicity mediated by H2 O2. We postulate that PA oxidation in presence of Cu yields H2 O2 which in turn permeates the plasma membrane and induced apoptosis. However, other cell lines exhibited different responses to these treatments, potentially providing a model for cell type- specific cytotoxic responses in the nervous system. The sensitivity of different neural and glial cell types to Cu-PAtreatment may therefore underlie the neurologic worsening occurring in some PA-treated WD patients. Our results also raise the possibility that the side effects of PA treatment might be reduced or prevented by administering antioxidants. © 2017 Katerji, Barada, Jomaa, Kobeissy, Makkawi, Abou-Kheir and Usta

    Effects of different starches on the physicochemical and sensory characteristics of extruded fish snacks

    Get PDF
    The market for snack foods is currently heading for healthier choices. Extrusion-based snacks made of starch are widespread but less nutrient-dense. Therefore, an effort to produce expanded snacks with higher protein was attempted. However, the physical properties of high protein extrudates are less desirable. Hence, different kind of starches were used in attempt to improve the physical properties of extrudates with high protein from scad fish. The objective of this study was to determine the effect of types and percentages of three starches, namely tapioca, sago and corn (50, 67, 75% db); on the physicochemical properties of extrudates from round scad fish powder (Decaptus madruasi). The formulations were extruded using a single screw extruder with a 3 mm circular die. The feeder and screw speed were maintained at 150 and 50 rpm, respectively. The barrel temperatures for each zone were 80°C (zone 1), 120°C (zone 2), 140°C (zone 3) and 160°C (zone 4). The results of the study revealed that all starch types at 75% increased the expansion ratio of extrudates to 47-56% compared with the inclusion of starches at 50%. All starch types at 75% also decreased the bulk density to 21-24% and hardness to 23-50% as compared to extrudates with the lowest amount of starch. The improvements in the physical properties were more prominent in the addition of tapioca starch. The highest amount of protein was found in extrudates with tapioca starch (20.8 to 30.4%). The sensory analysis and colour indicated similar results for all extrudates. The best formulation for the production of fish snacks was extrudates with 75% tapioca starch and 25% fish powder. The finding of this study is relevant and applicable in the production of high protein extrudates for children or health-conscious consumers, with the usage of tapioca starch to assist better expansion that improves the physical properties

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

    Get PDF
    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
    corecore