Effect of lead on zooplankton dynamics in Challawa River, Kano State, Nigeria

Lead concentration was determined with the aid of Atomic Absorption Spectrophotometer while zooplankton were collected with the aid of plankton net and analysed microscopically to assess their diversity and density in the Challawa River at four selected sites on fortnight basis between July 2006 and December 2007. The mean lead concentration was between 125 mg/L and 2.84 mg/L, far above maximum acceptable and allowable concentrations in drinking water of 0.05 mg/L and 0.10 mg/L respectively (WHO, 1996). The mean zooplankton density ranged between 3.09 Org/L and 10.26 Org/L. Only five protozoan, two insect, four copepod (plus one naplius I), one cladoceran and five rotifer species were identified during the study. The river quality decreased down stream, with least plankton recovery of 4 species at the industrial effluent inflow site and highest off-stream (site A) with 14 species. The site that experiences a direct inflow of industrial effluent was the most polluted (Odum’s Index = 0.22). Significant differences occurred in the lead concentration between the sites (

Flora composition of phytoplankton as bioindicators of water quality in Jakara dam, Kano state, Nigeria

A study on phytoplankton as bioindicators of water quality in Jakara Dam was carried out for a period of 12 months (March, 2013-February 2014). Phytoplankton and water samples were collected and analyzed using standard methods. Sampling sites designated as A, B, C, D, and E were chosen. Physico-chemical parameters showed temperature, secchi disk transparency, pH, and electrical conductivity ranged between 25.3-23.9, 10.7-57.9 cm, 7.9-7.7 and 856.7- 817.9μs/cm respectively, so also dissolved oxygen, biochemical oxygen demand, nitrate and phosphate ranged between 4.5-3.3 mg/l, 2.5-1.7 mg/l, 23.8-14.3 mg/l, and 15.8-12.5mg/l respectively. Cyanophyceae were the most dominant contributing 56.8% of the total flora composition, followed by Bacillariophyceae (23.2%) and Chlorophyceae (23.0%). A combined total of 23 species of phytoplankton were encountered. Cyanophyceae 9, Bacillariophyceae 7 and Chlorophyceae 7. The total flora count obtained was 3255.93 Org/l. The highest phytoplankton density was recorded at site D (870.18 Org/l) and lowest at site A (454.39 Org/l). Oscillatoria spp. had the highest total species count (1131.58) org/l while Anthophysa vegetans had the lowest (10.53 Org/l). High percentages of organic pollution indicators Oscillatoria spp and Microcystis aerogenosa were signs of deteriorating condition of the water quality. Shannon - Weiner’s and Evenness Indices values were higher in the months of wet season than in dry season, while the Simpson’s Index values were low. The total flora counts were higher in dry season. In the wet season, Pearson’s Coefficient analysis showed that there was positive relationship between temperature and nitrate and BOD at P< 0.05. Likewise between DO and phytoplankton, BOD and nitrate and phosphate at P< 0.01. During the period of this study, site A had low secchi disk transparency, high level of nitrate and phosphate. This is due to human activities taking place at the site. Shannon - Weiner’s Index value indicated that the site is more polluted. Government and stakeholders should strengthen their legislation against indiscriminate and improper waste disposal along water-ways, dams inclusive. This will ease inflow and check contamination to a large extent.Keywords: Bioindicators, Indicies, Jakara Dam, Physico-chemical parameters, Phytoplankto

Zooplankton as bioindicators ofwater quality in Jakara dam, Kano state, Nigeria

The study of zooplankton as bioindicators of water quality in Jakara Dam was carried out for a period of 12 months (March,2013-February 2014). Zooplankton and water samples were collected and analyzed using standard methods. Sampling sites designated as A, B,C,D, and E were chosen. Result of physico-chemical parameters analysed showed that temperature, secchi disk transparency, pH and electrical conductivity ranged between 25.3-23.9, 10.7-57.9 cm, 7.9-7.7 and 856.7- 817.9 μS/cm respectively, so also dissolved oxygen, biochemical oxygen demand, nitrate and phosphate ranged between 4.5-3.3 mg/l, 2.5-1.7 mg/l, 23.8-14.3 mg/l, and 15.8-12.5mg/l respectively. Among the zooplankton, Rotifers were the dominant, contributing 27.10% of the total fauna composition. Cladocerans constituted 26.99%, Cyclopoida 16.15%, Calanoida 15.08%, and Protozoans 14.68%. However, a combined total of 36 zooplankton species were encountered, Rotifers had 10, Cladocerans 10, Cyclopoida 6, Protozoans 6, and Calanoida 4. The total fauna composition recorded was 2606.58 Org/l with the highest zooplankton density recorded at site D (631.64 Org/l) and lowest at site A (384.31 Org/l). Bosmina longirostris had the highest total species count of 250.88 Org/l while Afrocyclops monodi had 7.02 Org/l. Rotifers are signs of deteriorating condition of the water quality. Pearson’s correlation existed between zooplankton, nitrate, phosphate and electrical conductivity at P<0.01. During the period of this study, site A had low secchi disk transparency,high level of nitrate and phosphate. This is due to human activities taking place at the site.In a bid to providing safe water for domestic and industrial uses, water treatment plant should be provided to help in water treatment especially at site A (Bela community) of this research area.Key words: Bela community, Deteriorating, Zooplankton, Water Quality, Jakara Da

Assessment of cotton-seed (Gossypium species) meal as ingredient in the diet of Clarias gariepinus juveniles

The effect of feeding graded levels of cotton GossypiumSpp. seed meal as an inclusion in the diet of Clariasgariepinus juveniles for growth performance was analysed in comparison with the conventional commercial fish feed. Six experimental rations formulated were cotton-seed Gossypium spp. meal replaced fish meal at graded levels of 20%, 30%, 40% 50%, and 100% and were fed to Clarias gariepinus juveniles for 56 days. The experiment was conducted in six outdoor concrete tanks in the Department of Biological Sciences Garden, Ahmadu Bello University, Zaria, Nigeria. Data for each parameter were subjected to Analysis of Variance (ANOVA) and the means for various experimental diets were compared for significant differences at 0.05% level of inclusion. The results showed that fish fed with diet contained 20% cottonseed meal (D1) gave the best Body Weight Gain (81.28g), Specific Growth Rate (2.23), and Condition Factor (1.49), while diet contained 30% cottonseed meal (D2) gave the least Weight Gain (49.67g), Specific Growth Rate (1.58) Conversion Ratio (3.64) and Condition factor (0.79). The results were significantly different (p<0.05) for both growth and feed utilization parameters. Therefore, cotton-seed meal can be used as a replacement for fish meal at 20% level of inclusion. The results established significant reduction in production cost while optimal production is achieved.Keywords: Cotton-seed (Gossypium species), Diet, Growth performance, Clariasgariepinus juvenile

Seasonal and Spatial Variations in Water Quality and Its Ecological Implications on Challawa River, Nigeria

The water quality of Challawa River, Kano, Nigeria at three sites was investigated for a period of eighteen months (January, 2005 - June, 2006). Results obtained showed some degree of variations along the river course. The pH, colour, temperature, bicarbonate and turbidity valuesincreased from sample site I (upstream), through site III (downstream) of the river. Levels of dissolved oxygen and phosphate decreased down the stream while biochemical oxygen demand, chemical oxygen demand, electrolytic conductivity, nitrate and sulphate fluctuated between sites. Significant differences (P < 0.05) between both sites and seasons for colour, pH, temperature, electrolytic conductivity, bicarbonate and sulphate exist while no significant difference (P > 0.05) was observed on both sites and seasons for turbidity, nitrate and phosphate. However, dissolved oxygen, biochemical oxygen demand and chemical oxygen demand were significantly different (P < 0.05) only between seasons. The implications of the results were discussed.Keywords: Physico-chemical quality, seasonal, spatial, variation, Challawa River, Kano

Central Asia and the globalisation of the contemporary legal consciousness

What is the logic which governs the processes of legal globalization? How does the transnational proliferation of legal forms operate in the contemporary geo-juridical space? What are the main defining characteristics of the currently dominant mode of transnational legal consciousness and how can the concept of legal consciousness help us understand better the historical ebb and flow of the Western-led projects of good governance promotion in regions like Central Asia after the fall of the Soviet Union? Using Duncan Kennedy’s seminal essay Three Globalizations of Law and Legal Thought as its starting platform, this essay seeks to explore these and a series of other related questions, while also drawing on the work of the Greek Marxist lawyer-philosopher Nicos Poulantzas to help elucidate some latent analytical stress-points in Kennedy’s broader theoretical framework. Reacting against the neo-Orientalist tone adopted across much of the contemporary field of Central Asian studies, it develops an alternative account of the internal history of the legal-globalizational encounter between the Western-based reform entrepreneurs and the national legal-political elites in Central Asia in the post-1991 period, complementing it with a detailed description of the general institutional and discursive structures within which this encounter took place

Identifying metabolic pathways for production of extracellular polymeric substances by the diatom Fragilariopsis cylindrus inhabiting sea ice

Diatoms are significant primary producers in sea ice, an ephemeral habitat with steep vertical gradients of temperature and salinity characterizing the ice matrix environment. To cope with the variable and challenging conditions, sea ice diatoms produce polysaccharide-rich extracellular polymeric substances (EPS) that play important roles in adhesion, cell protection, ligand binding and as organic carbon sources. Significant differences in EPS concentrations and chemical composition corresponding to temperature and salinity gradients were present in sea ice from the Weddell Sea and Eastern Antarctic regions of the Southern Ocean. To reconstruct the first metabolic pathway for EPS production in diatoms, we exposed Fragilariopsis cylindrus, a key bi-polar diatom species, to simulated sea ice formation. Transcriptome profiling under varying conditions of EPS production identified a significant number of genes and divergent alleles. Their complex differential expression patterns under simulated sea ice formation was aligned with physiological and biochemical properties of the cells, and with field measurements of sea ice EPS characteristics. Thus, the molecular complexity of the EPS pathway suggests metabolic plasticity in F. cylindrus is required to cope with the challenging conditions of the highly variable and extreme sea ice habitat

Global, regional, and national incidence, prevalence, and years lived with disability for 328 diseases and injuries for 195 countries, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

As mortality rates decline, life expectancy increases, and populations age, non-fatal outcomes of diseases and injuries are becoming a larger component of the global burden of disease. The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of prevalence, incidence, and years lived with disability (YLDs) for 328 causes in 195 countries and territories from 1990 to 2016

Erratum: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning