57 research outputs found
Optimisation Study on the Production of Anaerobic Digestate Compost for Application on Arable Soils
Organic fraction of municipal solid waste (OFMSW) is a rich substrate for biogas and compost production. Anaerobic Digestate compost (ADC) is an organic fertilizer produced from stabilized residuals of anaerobic digestion of OFMSW. This paper reports the result of studies carried out to optimise the production of ADC from organic fractions of domestic wastes and the effects of ADC amendments on soil quality. In general, ADC amended soils showed greater bioactivity and soil biomass compared to unamended soils. The diversity of soil community structures also increased with increasing ADC amendments with fungal populations showing greater variation than bacteria, suggesting that ADC amendment has greater impact on fungi than bacteria. It was found that seed germination in ADC amended soils increased with dilution and incubation time, suggesting that lower ADC application rates and longer lag periods between soil applications and planting can improve the benefits of ADC as an amendment for arable soil.
Keywords: Anaerobic digestion; anaerobic digestate compost; food waste; green waste, postaerobic digestion; soil qualit
Fertility Status of Fadama Soils in Gantsare Village, Wamakko Local Government, Sokoto State As Affected by Cement Dust
A study was conducted in Gantsare village, Wamakko local government, Sokoto state to determine the effect of cement dust emitted from Sokoto cement factory on the fertility of fadama soils. Soil samples were collected in June, 2008 from the eastern, northeastern, and southeastern parts of the village and Girabshi; a nearby village with least effect of the dust. The samples were collected at two depths (0-15 and 15-30 cm) using simple random sampling method. Randomized complete block design (RCBD) was employed, replicated three times, making a total of 24 samples. The samples were analyzed for pH, OC, CEC, total N, available P, exchangeable bases (Ca, Mg, K and Na) and particle size. Almost all parameters determined were found to be statistically significant (P < 0.01). OC was found to be lower in concentration in the areas closer to the factory; eastern part6.25 respectively, likewise CEC and exchangeable bases. The trend in the results observed may be attributed to possible adverse effects of
the dust on microbial population, reduction in the availability of some nutrients and a favour on the concentrations of exchangeable bases and CEC. The topsoils showed better results of all the soil chemical properties. The study recommends minimization of the amount of dust reaching agricultural soils and the use of phosphorus and nitrogen fertilizer supplements as soil management practices to enhance soil fertility status and enhance adequate crop yield in the area.
Key words:Cement dust, fertility status, fadama soils, soil chemical properties, soil management
Ipomea asarifolia (Desr), A Potential Cover Crop for Soil Fertility Improvement in The Sudan Savanna Region, Nigeria
The effect of Ipomea asarifolia on physico - chemical properties of the soils at Usmanu Danfodiyo University, Sokoto main campus, in the Sudan Savanna of Nigeria was investigated. The study determined the effect of the plant on some physical and chemical properties of soils, found out the nutrient retention ability of the plant in the soils and the variation of the effect with distance within the plants’ canopy. A total of 48 samples were collected from four different sites within Usmanu Danfodiyo
University main Campus; VC complex area, University stadium area, Behind new library area and opposite IBB centre area and four distances from the plant (control, plant base, 0.5 m and 1 m from the plant base). Samples were collected for use in a randomized complete block design (RCBD) experiment with three replicates. Soil pH, Organic C, CEC, total N, available P, K, Ca and Mg concentrations were determined, particle size analysis was also carried out. The results were subjected to analysis of variance (ANOVA), where significant F values were obtained, the means were separated by Duncan multiple range tests (DMRT). The difference among the sites and the distances were found to be statistically significant (P VC complex area > New library area > IBB centre area. On the other hand, the effect on all the parameters was found to
decrease with distance from the plant with the base of the plant having the highest organic C, CEC, total N, available P and exchangeable K, Ca and Mg; 6.83 g kg-1, 5.00 cmol kg-1, 0.42 g kg-1, 10.82 mg kg-1 and 0.26, 0.50 and 0.97 cmol kg-1 respectively, while the control soils had the least values; 3.46 g kg-1, 4.00 cmol kg-1, 0.12 g kg-1, 7.43 mg kg-1, 0.21, 0.38, and 0.45 cmol kg-1 respectively. The effect was attributed to the accumulation of organic matter around the plant and its ability to prevent erosion by both water and wind thus retaining nutrients making it a suitable cover crop for soil fertility improvement
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
Pneumococcal carriage in sub-Saharan Africa--a systematic review.
BACKGROUND: Pneumococcal epidemiology varies geographically and few data are available from the African continent. We assess pneumococcal carriage from studies conducted in sub-Saharan Africa (sSA) before and after the pneumococcal conjugate vaccine (PCV) era. METHODS: A search for pneumococcal carriage studies published before 2012 was conducted to describe carriage in sSA. The review also describes pneumococcal serotypes and assesses the impact of vaccination on carriage in this region. RESULTS: Fifty-seven studies were included in this review with the majority (40.3%) from South Africa. There was considerable variability in the prevalence of carriage between studies (I-squared statistic = 99%). Carriage was higher in children and decreased with increasing age, 63.2% (95% CI: 55.6-70.8) in children less than 5 years, 42.6% (95% CI: 29.9-55.4) in children 5-15 years and 28.0% (95% CI: 19.0-37.0) in adults older than 15 years. There was no difference in the prevalence of carriage between males and females in 9/11 studies. Serotypes 19F, 6B, 6A, 14 and 23F were the five most common isolates. A meta-analysis of four randomized trials of PCV vaccination in children aged 9-24 months showed that carriage of vaccine type (VT) serotypes decreased with PCV vaccination; however, overall carriage remained the same because of a concomitant increase in non-vaccine type (NVT) serotypes. CONCLUSION: Pneumococcal carriage is generally high in the African continent, particularly in young children. The five most common serotypes in sSA are among the top seven serotypes that cause invasive pneumococcal disease in children globally. These serotypes are covered by the two PCVs recommended for routine childhood immunization by the WHO. The distribution of serotypes found in the nasopharynx is altered by PCV vaccination
Population genetic structure of Streptococcus pneumoniae in Kilifi, Kenya, prior to the introduction of pneumococcal conjugate vaccine.
BACKGROUND: The 10-valent pneumococcal conjugate vaccine (PCV10) was introduced in Kenya in 2011. Introduction of any PCV will perturb the existing pneumococcal population structure, thus the aim was to genotype pneumococci collected in Kilifi before PCV10. METHODS AND FINDINGS: Using multilocus sequence typing (MLST), we genotyped >1100 invasive and carriage pneumococci from children, the largest collection genotyped from a single resource-poor country and reported to date. Serotype 1 was the most common serotype causing invasive disease and was rarely detected in carriage; all serotype 1 isolates were members of clonal complex (CC) 217. There were temporal fluctuations in the major circulating sequence types (STs); and although 1-3 major serotype 1, 14 or 23F STs co-circulated annually, the two major serotype 5 STs mainly circulated independently. Major STs/CCs also included isolates of serotypes 3, 12F, 18C and 19A and each shared ≤ 2 MLST alleles with STs that circulate widely elsewhere. Major CCs associated with non-PCV10 serotypes were predominantly represented by carriage isolates, although serotype 19A and 12F CCs were largely invasive and a serotype 10A CC was equally represented by invasive and carriage isolates. CONCLUSIONS: Understanding the pre-PCV10 population genetic structure in Kilifi will allow for the detection of changes in prevalence of the circulating genotypes and evidence for capsular switching post-vaccine implementation
Effect of Pneumococcal Conjugate Vaccination on Serotype-Specific Carriage and Invasive Disease in England: A Cross-Sectional Study
A cross sectional study by Stefan Flasche and coworkers document the serotype replacement of Streptococcus pneumoniae that has occurred in England since the introduction of PCV7 vaccination
Travel burden and clinical presentation of retinoblastoma: analysis of 1024 patients from 43 African countries and 518 patients from 40 European countries
BACKGROUND: The travel distance from home to a treatment centre, which may impact the stage at diagnosis, has not been investigated for retinoblastoma, the most common childhood eye cancer. We aimed to investigate the travel burden and its impact on clinical presentation in a large sample of patients with retinoblastoma from Africa and Europe. METHODS: A cross-sectional analysis including 518 treatment-naïve patients with retinoblastoma residing in 40 European countries and 1024 treatment-naïve patients with retinoblastoma residing in 43 African countries. RESULTS: Capture rate was 42.2% of expected patients from Africa and 108.8% from Europe. African patients were older (95% CI -12.4 to -5.4, p<0.001), had fewer cases of familial retinoblastoma (95% CI 2.0 to 5.3, p<0.001) and presented with more advanced disease (95% CI 6.0 to 9.8, p<0.001); 43.4% and 15.4% of Africans had extraocular retinoblastoma and distant metastasis at the time of diagnosis, respectively, compared to 2.9% and 1.0% of the Europeans. To reach a retinoblastoma centre, European patients travelled 421.8 km compared to Africans who travelled 185.7 km (p<0.001). On regression analysis, lower-national income level, African residence and older age (p<0.001), but not travel distance (p=0.19), were risk factors for advanced disease. CONCLUSIONS: Fewer than half the expected number of patients with retinoblastoma presented to African referral centres in 2017, suggesting poor awareness or other barriers to access. Despite the relatively shorter distance travelled by African patients, they presented with later-stage disease. Health education about retinoblastoma is needed for carers and health workers in Africa in order to increase capture rate and promote early referral
Bacterial Load of Pneumococcal Serotypes Correlates with Their Prevalence and Multiple Serotypes Is Associated with Acute Respiratory Infections among Children Less Than 5 Years of Age
Background: Among pneumococcal serotypes, some serotypes are more prevalent in the nasopharynx than others; determining factors for higher prevalence remain to be fully explored. As non-vaccine serotypes have emerged after the introduction of 7-valent conjugate vaccines, study of serotype specific epidemiology is in need. When two or more serotypes co-colonize, they evolve rapidly to defend host\u27s immune responses; however, a clear association of cocolonization with a clinical outcome is lacking. Methods: Children less than 5 years old who were admitted to hospital due to acute respiratory infections (ARI) (n = 595) and healthy children (n = 350) were recruited. Carriage of pneumococcus was determined by culture and lytA PCR in the nasopharyngeal samples. Serotype/serogroup detection and its quantification were done by the nanofluidic real time PCR system. Spearman\u27s correlation and logistic regression were used to examine a correlation of serotype/serogroup specific bacterial load with its prevalence and an association of co-colonization with ARI respectively. Results: Serotype/serogroup specific bacterial load was correlated with its prevalence, both in ARI cases (Spearman\u27s rho = 0.44, n = 186; P<0.0001) and healthy children (Spearman\u27s rho = 0.41, n = 115; P<0.0001). The prevalence of multiple serotypes was more common in ARI cases than in healthy children (18.5% vs 7.1%; aOR 2.92, 95% CI: 1.27-6.71; P = 0.01). The dominant serotype in the co-colonization had a 2 log10 higher bacterial load than the subdominant serotype, both in ARI cases (P<0.001) and healthy children (P<0.05). Conclusions: High bacterial load in the nasopharynx may help transmit pneumococci among hosts, and increase the chance of successful acquisition and colonization. Co-colonization of multiple serotypes of pneumococci is linked with ARI, which infers the interactions of multiple serotypes may increase their pathogenicity; however, they may compete for growth in number
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