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Mechanistic studies on Diels-Alder [4þ2] cycloaddition reactions ofa,b-substituted cyclobutenones: Role of substituents in regio- andstereoselectivity
(Elsevier Ltd., 216-11-03) Fosu, Evans; Tia, Richard; Adei, Evans
Diels-Alder reactions of substituted cyclobutenones with 6-methoxy-1-vinyl-3,4-dihydronaphthaleneand methoxy-substituted-1,3-butadiene have been studied with DFT. In the reactions of 6-methoxy-1-vinyl-3,4-dihydronaphthalene with cyclobutenone anda-bromocyclobutenone, the formation of themetaandorthoisomers have the same barriers, indicating that the two isomers might be formed in equalproportions, contrary to earlier reports. The regiochemistry of the reaction is mainly controlled by theketone functionality at C1 on the dienophiles. In the reactions of methoxy-substituted-1,3-butadienewith cyclobutenone anda,b-substituted cyclobutenones theortho/endoandpara/endostereo-isomericpathways are the most favorable pathways, changing toexoselectivity when OH, Br, CH3are placedon theb-carbon of the cyclobutenone, but still withorthoandpararegioselectivity. The stereoselectivityis independent of the bulkiness of substituents. The stability of substituted cycloadducts are lowercompared to unsubstituted adducts and this explains why thea-cyanoketones anda-bromoketoneproducts readily undergotrans-methylation and angular-alkylation as electrophiles.
Hypertension and renal failure in Kumasi, Ghana
(Human Hypertension, 1999-01-13) Plange-Rhule, J; Phillips, Richard Odame; Acheampong, JW; Saggar-Malik, AK; Cappuccio, FP; et.al
Hypertension is common in West Africa and likely to become more common as urbanisation increases. There are at present few facilities for the detection and management of hypertension so the influence it has on overall morbidity and mortality in the population is not clear. The objectives of the study were to assess: (a) renal disease and blood pressure related admissions and deaths among acute medical admissions to Komfo Anokye Teaching Hospital, Kumasi, during an 8-month period; and (b) the burden of renal disease among out-patient hypertensives at the same hospital. Ward admission books were examined in the four acute medical wards to ascertain admission diagnosis and cause of death (two 4-month periods in 1995 and 1996). Clinical assessment (blood pressure, plasma creatinine, proteinuria) was also made of 448 consecutive out-patient hypertensives seen between March 1995 and April 1996. Five Keywords: hypertension; renal disease; plasma creatinine; Ghanaians; West Africans Introduction Hypertension is an increasing problem in people of West African descent living in the western world.1,2 Studies in the United States3,4 and Britain5,6 have shown hypertension to be very common and its complications (stroke, heart failure, renal failure) a major cause of morbidity and mortality in black subjects in these countries. There are few data on the prevalence of hypertension in West Africa. Studies suggest that the prevalence of hypertension is higher in urban than rural areas.7–9 Increasing urbanisation in West Africa is associated with an increasing prevalence of hypertension9 so the burden of hypertension and its related complications on morbidity and mortality will rise. Indeed, hypertensive renal damage is the main cause of end-stage renal failure in black populations both in the UK10 and in West Africa.11,12 There is a lack of primary care facilities for the detection of hypertension in West Africa and clinics Correspondence: Dr JB Eastwood, Department of Renal Medicine, St George’s Hospital Medical School, Cranmer Terrace, London SW17 ORE, UK Received 27 March 1998; revised 25 July 1998; accepted 31 July 1998 hundred and ninety-three (17.9%) of 3317 acute medical admissions were ascribable to a cardiovascular cause (hypertension, heart failure, stroke); 171 (28.8%) of these died. One hundred and sixty-six (5.0%) had renal disease of whom 45 (27.1%) died, usually of end-stage renal disease. Among the 448 hypertensive out-patients, 30.2% (110 out of 365) had a plasma creatinine .140 mmol/l (48 > 400 mmol/l) and 25.5% (96 out of 376) had proteinuria. Eighty-nine of the 448 had a diastolic blood pressure >115 mm Hg; in this group 38 (42.7%) had a plasma creatinine of .140 mmol/l (and 18 or 20.2% >400 mmol/l). In conclusion, cardiovascular and renal disease are important contributors to morbidity and mortality among acute medical admissions to a large city hospital in Ghana. Among out-patient hypertensives renal disease is an important complication, especially in those with the more severe hypertension.
Genomic Arrangement of Nod Gene Sequences of Bradyrhizobium Isolates from TGx Soybean Genotypes in Relation to Bradyrhizobium USDA110
(Current Plant Science and Biotechnology in Agriculture, 2000) Abaidoo, R. C.; Keyser, H. H.; Singleton, P. W.; Borthakur, D.
Soybean nodulates with specific rhizobia and usually requires inoculation with Bradyrhizobium japonicum strains. Several varieties (e.g., Malayan and Orba) introduced to Africa (Pulver et al., 1982;) were however adequately nodulated in soils that had no previous inoculation with B. japonicum while cultivars from North America were poorly nodulated. The freely nodulating soybean genotypes, termed promiscuous, however, had poor agronomic characteristics. The International Institute of Tropical Agriculture (IITA) selected soybean genotypes that combined the free nodulating traits of the promiscuous genotypes and the improved agronomic characteristics of the North American genotypes. The resultant TGx genotypes, widely cultivated in western and eastern Africa have poor yields due to ineffective nodulation (Okereke and Eaglesham, 1992). This observation led to the suggestion that the TGx soybean genotypes would benefit from B. japonicum inoculation. It is therefore important that the genetic relatedness of the indigenous rhizobia nodulating these soybean genotypes to recommended inoculum strains (e.g., B. japonicum USDA 110) needs to be elucidated. A total of 258 Bradyrhizobium
Detection and management of zoonotic diseases at the Kumasi slaughterhouse in Ghana
(Acta Tropica, 2000) Otupiri, Easmon; Adam, M.; Laing, E.; Akanmori, B. D.; 0000-0001-8986-1648
Slaughterhouse surveys are important in the detection and management of zoonotic diseases. Routine reports from the Kumasi slaughterhouse, in the Ashanti region of Ghana, include cases of zoonotic diseases. Due to its location and size, Kumasi is the major cattle market and an important transit point for cattle trade from places within and outside Ghana. This present study was designed to examine slaughterhouse reports and to explore the nature of the knowledge, attitude and practices of butchers who operate at this slaughterhouse, in relation to zoonoses. The study was largely descriptive, employing qualitative methods and tools. Butchers were interviewed and their practices along the production line observed. The study indicates that zoonotic diseases are frequently detected at the Kumasi slaughterhouse. However the knowledge, attitudes, practices and beliefs of the butchers are largely inadequate for their profession in view of the important public health role that butchers play. The butchers have never received any form of training. It is recommended that the butchers receive training on a regular basis and that laws be formulated and implemented to protect the health of the butchers and the general public.
Bradyrhizobium spp. (TGx) isolates nodulating the new soybean cultivars in Africa are diverse and distinct from bradyrhizobia that nodulate North American soybeans
(Academia, 2000) Abaidoo R. C; Keyser Harold H.; Singleton Paul W.; Borthakur Dulal
The newly developed cultivars of soybean in Africa, known as Tropical Glycine cross (TGx), are nodulated by bradyrhizobia indigenous to African soils, here designated Bradyrhizobium spp. (TGx). Isolates of Bradyrhizobium spp. (TGx) obtained from nodules of TGx soybeans that were inoculated with soils from 65 locations in six African countries were characterized and grouped into 11 phylogenetic clusters on the basis of RFLP of the 16S rRNA gene. Five restriction enzymes (RsaI, HinfI, MspI, CfoI and HaeIII) established RFLP groups within these Bradyrhizobium spp. (TGx) isolates, which were used to construct a phylogenetic tree showing their genetic relationship with other Bradyrhizobium species. RFLP analysis indicated that Bradyrhizobium spp. (TGx) is a heterogeneous group with some isolates related to Bradyrhizobium japonicum and Bradyrhizobium elkanii strains and some to Bradyrhizobium spp. (misc.) reference strains isolated from a variety of tropical legumes. The heterogeneity within the large phylogenetic clusters was further examined through analysis of randomly amplified polymorphic DNA (RAPD) using GC rich PCR primers. The RAPD analysis showed additional heterogeneity in the Bradyrhizobium spp. (TGx) phylogenetic clusters, which was not revealed by separations based on RFLP analysis. The Bradyrhizobium spp. (TGx) isolates were classified into effective and ineffective types based on their symbiotic performance on TGx soybean. The isolates were randomly distributed throughout the phylogenetic clu
Comparison of molecular and antibiotic resistance pro®le methods for the population analysis of Bradyrhizobium spp. (TGx) isolates that nodulate the new TGx soybean cultivars in Africa
(The Society for Applied Microbiology, 2002) Abaidoo R. C; Keyser H.H.; Singleton P.W.; Borthakur D.
Aims: Comparison of molecular and antibiotic resistance pro®le methods to identify an easy method that can differentiate between strains of introduced Bradyrhizobium japonicum and the indigenous Bradyrhizobium spp. (TGx) isolates which nodulate the newly developed TGx soybean cultivars in Africa. Methods and Results: Restriction fragment length polymorphism (RFLP) of 16S rDNA generated by ®ve restriction enzymes, banding patterns in Southern hybridization using nod and nif genes as probes, and resistance patterns of the isolates to nine antibiotics, were used to group 26 Bradyrhizobium spp. (TGx) isolates and four other Bradyrhizobium strains. The clusters of isolates obtained from the four grouping methods were all different, although all methods revealed large genetic diversity among the isolates. Conclusions: Results indicate that the antibiotic resistance pro®le method is as good as the three molecular methods used in this study for phylogenetic grouping of the Bradyrhizobium spp. (TGx) isolates, which may serve as a basis for further characterization of selected isolates from each group. Signi®cance and Impact of the Study: The antibiotic resistance pro®le method can be used as a simple means of assessing genetic variability and grouping of a large number of Bradyrhizobium spp. (TGx) isolates. Representative isolates from each group can then be selected for further characterization.
Prevalence, Detection, Management, and Control of Hypertension in Ashanti, West Africa
(American Heart Association, 2004-05) Cappuccio, Francesco P.; Micah, Frank B.; Emmett, Lynsey; Kerry, Sally M.; Phillips, Richard Odame; et. al
Hypertension and stroke are important threats to the health of adults in sub-Saharan Africa. Nevertheless, detection of hypertension is haphazard and stroke prevention targets are currently unattainable. Prevalence, detection, management, and control of hypertension were assessed in 1013 men (n 385) and women (n 628), both aged 55 [SD 11] years, living in 12 villages in Ashanti, Ghana. Five hundred thirty two lived in semi-urban and 481 in rural villages. The participants underwent measurements of height, weight, and blood pressure (BP) and answered a detailed questionnaire. Hypertension was defined as BP 140 and/or 90 mm Hg or being on drug therapy. Women were heavier than men. Participants in semi-urban areas were heavier and had higher BP (129/76 [26/14] versus 121/72 [25/13] mm Hg; P 0.001 for both) than in rural areas. Prevalence of hypertension was 28.7% overall and comparable in men and women, but higher in semi-urban villages (32.9% [95% CI 28.9 to 37.1] versus 24.1% [20.4 to 28.2]), and increased with age. Detection rate was lower in men than women (13.9% versus 27.3%; P 0.007). Treatment and control rates were low in both groups (7.8% and 4.4% versus 13.6% and 1.7%). Detection, treatment, and control rates were higher in semi-urban (25.7%, 14.3%, and 3.4%) than in rural villages (16.4%, 6.9%, and 1.7%). Hypertension is common in adults in central Ghana, particularly in urban areas. Detection rates are suboptimal in both men and women, especially in rural areas. Adequate treatment of high BP is at a very low level. There is an urgent need for preventive strategies on hypertension control in Ghana. (Hypertension. 2004;43:1017-1022.)
In Vitro Killing of Mycobacterium ulcerans by Acidified Nitrite
(Antimicrobial Agents and Chemotherapy, 2004-08) Phillips, Richard Odame; Kuijper, S.; Benjamin, N.; Wansbrough-Jones, M.; Wilks, M.; et. al
Mycobacterium ulcerans, which causes Buruli ulcer, was exposed to acidified nitrite or to acid alone for 10 or 20 min. Killing was rapid, and viable counts were reduced below detectable limits within 10 min of exposure to 40 mM acidified nitrite. M. ulcerans is highly susceptible to acidified nitrite in vitro.
Pilot Randomized Double-Blind Trial of Treatment of Mycobacterium ulcerans Disease (Buruli Ulcer) with Topical Nitrogen Oxides
(Antimicrobial Agents and Chemotherapy, 2004-08) Phillips, Richard Odame; Adjei, O.; Lucas, S.; Benjamin, N.; Wansbrough-Jones, Mark
Mycobacterium ulcerans disease (Buruli ulcer) is a serious ulcerating skin disease which is common in many tropical countries. Standard treatment, by extensive excision and skin grafting, is not available in rural communities where the disease is common. We evaluated the efficacy and safety of treatment with topical nitrogen oxides. Thirty-seven patients with a clinical diagnosis of Buruli ulcer caused by M. ulcerans disease were randomly assigned to one of two groups. In one group, two creams containing sodium nitrite (6%, wt/wt) or citric acid monohydrate (9%, wt/wt) were applied daily for 6 weeks, while the other group received a placebo. In the second 6 weeks, both groups received the nitrogen oxide-generating combination of creams. Treatment was continued for another 4 weeks for patients whose ulcers were not healed after 12 weeks. The ulcer surface area was monitored by weekly tracings made by assessors blinded to the treatment. In the first 6 weeks, patients on sodium nitrite and citric acid monohydrate (group I, active treatment) showed a rapid decrease in ulcer size from 28.6 5.6 cm2 (mean standard error) to 12.6 3.2 cm2, a decrease significantly greater than that in group II (from 15.3 3.1 to 11.7 3.7 cm2; P 0.03). Five ulcers in the placebo group enlarged during this period, compared with one in the active group. In the second 6 weeks (both groups on active treatment), the rates of healing were similar for the two groups and there was a significant reduction in ulcer size in group II (previously on placebo) compared to the first 6 weeks. Yellow pigmentation of the skin, which disappeared 3 days after treatment was stopped, was the only side effect to date. We conclude that creams releasing nitrogen oxides increase the healing rate of ulcers caused by M. ulcerans infection with minimal adverse events. This is the first controlled trial of any form of therapy which demonstrates efficacy in treating this disease.
On-farm evaluation of biological nitrogen fixation potential and grain yield of Lablab and two soybean varieties in the northern Guinea savanna of Nigeria
(Springer, 2005) Okogun J.A.; Sanginga N.; Abaidoo R. C; Dashiell K.E.; Diels J.; 0000-0002-1235-2252
Several legumes with high biological nitrogen fixation (BNF) potentials have been studied in on-station trials. The processes involved in BNF and the benefits of these species to crop production need to be evaluated using farmers’ management practices in farmers’ fields. An on-farm trial with 20 farmers was conducted in the northern Guinea savanna (NGS) of Nigeria. The aims were to evaluate the BNF potentials of an improved soybean variety (TGx 1448-2E) and a local variety (Samsoy-2) when inoculated with Bradyrhizobium strains, and of Lablab in farmer-managed and researcher-managed soybean-maize and Lablab-maize crop rotation systems. The level of soil P was generally low with more than 50% of the fields having less than the critical P level. The plant available P content was statistically significantly (P = 0.05) correlated with P in grain (r = 0.60), P in the shoot (r = 0.68), grain yield (r = 0.40) and nodule weight (r = 0.35). Variations in plant parameters (nodulation, shoot dry matter, percentage nitrogen derived from the air [%Ndfa], grain yield, and nutrient uptake) among and within farmers’ fields were attributed to differences in soil fertility and crop management. About 60% of the fields were mod erately fertile, sufficient to support legume establishment, while about 30% of the farmers’ fields had a low fertility level. For farmers in the study area to benefit from the BNF potentials of the legumes, an external P fertilizer input was necessary as well as suitable crop management practices because all parameters mea sured in the researcher-managed plots were higher than in the farmer-managed plots.
Blood pressure patterns in rural, semi-urban and urban children in the Ashanti region of Ghana, West Africa
(BioMed Central, 2005) Agyemang Charles; Redekop K William; Owusu-Dabo Ellis; Bruijnzeels A Marc
Background: High blood pressure, once rare, is rapidly becoming a major public health burden in sub-Saharan/Africa. It is unclear whether this is reflected in children. The main purpose of this study was to assess blood pressure patterns among rural, semi-urban, and urban children and to determine the association of blood pressure with locality and body mass index (BMI) in this sub Saharan Africa setting. Methods: We conducted a cross-sectional survey among school children aged 8–16 years in the Ashanti region of Ghana (West-Africa). There were 1277 children in the study (616 boys and 661 females). Of these 214 were from rural, 296 from semi-urban and 767 from urban settings. Results: Blood pressure increased with increasing age in rural, semi-urban and urban areas, and in both boys and girls. The rural boys had a lower systolic and diastolic blood pressure than semi urban boys (104.7/62.3 vs. 109.2/66.5; p < 0.001) and lower systolic blood pressure than urban boys (104.7 vs. 107.6; p < 0.01). Girls had a higher blood pressure than boys (109.1/66.7 vs. 107.5/63.8; p < 0.01). With the exception of a lower diastolic blood pressure amongst rural girls, no differences were found between rural girls (107.4/64.4) and semi-urban girls (108.0/66.1) and urban girls (109.8/67.5). In multiple linear regression analysis, locality and BMI were independently associated with blood pressure in both boys and girls. Conclusion: These findings underscore the urgent need for public health measures to prevent increasing blood pressure and its sequelae from becoming another public health burden. More work on blood pressure in children in sub-Saharan African and other developing countries is needed to prevent high blood pressure from becoming a major burden in many of these countries.
Efficacy of the Combination Rifampin-Streptomycin in Preventing Growth of Mycobacterium ulcerans in Early Lesions of Buruli Ulcer in Humans
(American Society for Microbiology, 2005-04-29) Etuaful, S.; Carbonnelle, B.; Phillips, Richard Odame; Evans, M.; Ofori-Adjei, D.; et.al
Mycobacterium ulcerans disease is common in some humid tropical areas, particularly in parts of West Africa, and current management is by surgical excision of skin lesions ranging from early nodules to extensive ulcers (Buruli ulcer). Antibiotic therapy would be more accessible to patients in areas of Buruli ulcer endemicity. We report a study of the efficacy of antibiotics in converting early lesions (nodules and plaques) from culture positive to culture negative. Lesions were excised either immediately or after treatment with rifampin orally at 10 mg/kg of body weight and streptomycin intramuscularly at 15 mg/kg of body weight daily for 2, 4, 8, or 12 weeks and examined by quantitative bacterial culture, PCR, and histopathology for M. ulcerans. Lesions were measured during treatment. Five lesions excised without antibiotic treatment and five lesions treated with antibiotics for 2 weeks were culture positive, whereas three lesions treated for 4 weeks, five treated for 8 weeks, and three treated for 12 weeks were culture negative. No lesions became enlarged during antibiotic treatment, and most became smaller. Treatment with rifampin and streptomycin for 4 weeks or more inhibited growth of M. ulcerans in human tissue, and it provides a basis for proceeding to a trial of antibiotic therapy as an alternative to surgery for early M. ulcerans disease.
Pesticide and Pathogen Contamination of Vegetables in Ghana’s Urban Markets
(KNUST, 2005-06) RC. Abaidoo,; 0000-0002-1235-2252
The objective of the study was to determine and compare the current level of exposure of the Ghanaian urban population to hazardous pesticide and fecal coliform contam ination through the consumption of fresh vegetables produced in intensive urban and periurban smallholder agriculture with informal wastewater irrigation. A total of 180 vegetable sam ples (lettuce, cabbage, and spring onion) were randomly col lected under normal purchase conditions from 9 major markets and 12 specialized selling points in 3 major Ghanaian cities: Accra, Kumasi and Tamale. The samples were analyzed for pesticide residue on lettuce leaves, total and fecal coliforms, and helminth egg counts on all three vegetables. Chlopyrifos (Dursban) was detected on 78% of the lettuce, lindane (Ga malin 20) on 31%, endosulfan (Thiodan) on 36%, lambda cyhalothrin (Karate) on 11%, and dichloro-diphenyl-trichlo roethane on 33%. Most of the residues recorded exceeded the maximum residue limit for consumption. Vegetables from all 3 cities were fecally contaminated and carried fecal coliform populations with geometric mean values ranging from 4.0 · 103 to 9.3 · 108 g–1 wet weight and exceeded recommended standards. Lettuce, cabbage, and spring onion also carried an average of 1.1, 0.4, and 2.7 helminth eggs g–1, respectively. The eggs were identified as those of Ascaris lumbricoides, Ancylostoma duodenale, Schistosoma heamatobium, and Trichuris trichiura. Because many vegetables are consumed fresh or only slightly cooked, the study shows that intensive vegetable production, common in Ghana and its neighboring countries, threatens public health from the microbiologic and pesticide dimensions. Standard recommendations to address this situation (better legislations, law enforcement, or inte grated pest management) often do not match the capabilities of farmers and authorities. The most appropriate entry point for risk decrease that also addresses postharvest contamination is washing vegetables before food preparation at the household or ‘‘chop’’ bar (street restaurant)
Mycobacterium ulcerans disease
(Bulletin of the World Health Organization, 2005-10) Phillips, Richard Odame; Werf, Tjip S. van der; Stienstra, Ymkje; Johnson, R. Christian; Adjei, Ohene; et. al
Mycobacterium ulcerans disease (Buruli ulcer) is an important health problem in several west African countries. It is prevalent in scattered foci around the world, predominantly in riverine areas with a humid, hot climate. We review the epidemiology, bacteriology, transmission, immunology, pathology, diagnosis and treatment of infections. M. ulcerans is an ubiquitous micro-organism and is harboured by fish, snails, and water insects. The mode of transmission is unknown. Lesions are most common on exposed parts of the body, particularly on the limbs. Spontaneous healing may occur. Many patients in endemic areas present late with advanced, severe lesions. BCG vaccination yields a limited, relatively short-lived, immune protection. Recommended treatment consists of surgical debridement, followed by skin grafting if necessary. Many patients have functional limitations after healing. Better understanding of disease transmission and pathogenesis is needed for improved control and prevention of Buruli ulcer.
Retrieval of stratospheric NO3 vertical profiles from SCIAMACHY lunar occultation measurement over the Antarctic
(Journal of Geophysical Research, 2005-10-26) Amekudzi, L. K.; Sinnhuber, B.-M.; Sheode, N. V.; Meyer, J.; Rozanov, A.; Lamsal, L. N.; Bovensmann, J. P. Burrows
[1] NO3 vertical profiles have been retrieved over the Antarctic (60 –90 S) from the Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) lunar occultation spectra, using the visible spectral band (610–680 nm) containing NO3 absorption bands at 623 and 662 nm. The retrieved NO3 profiles agree well with calculations from a photochemical model constrained by retrieved O3 and analyzed temperatures in the altitude range between 24 and 45 km. Below about 35–40 km, observed NO3 is well reproduced by photochemical steady state calculations. Differences between observed and modeled NO3 are within the estimated accuracy of 20–35%, demonstrating the consistency of the NO3 retrieval and model.
MINERAL NUTRIENT UPTAKE AND REMOVAL BY COWPEA, SOYBEAN AND MAIZE CULTIVARS IN WEST AFRICA, AND IMPLICATIONS FOR CARBON CYCLE EFFECTS ON SOIL ACIDIFICATION
(Cambridge University Press, 2006) RANDALL P. J; Abaidoo R. C; HOCKING P. J.; SANGINGA N.
A field study of cowpea, soybean and maize was made at Ibadan, Nigeria, to determine the uptake of mineral nutrients and quantities removed in crop residues and seed. Concentrations of N, the major cations (K, Ca, Mg and Na) and major anions (P, S and Cl), and the micronutrients (Fe, Mn, Zn and Cu) were determined in shoots harvested at flowering and maturity. Concentrations of excess cations in shoots at flowering were 135 cmolc kg−1 for soybean, 158 cmolc kg−1 for cowpea and 58 cmolc kg−1 for maize. In crop residues and seed at maturity, the values decreased to 75 and 56 cmolc kg−1 respectively for soybean, 68 and 27 cmolc kg−1 respectively for cowpea, and 52 and 10 cmolc kg−1 respectively for maize. Nutrient and excess cation concentrations were also measured in 13 soybean and eight cowpea lines grown in replicated field trials at Fashola in the derived savanna zone and Shika in the northern Guinea savanna zone of Nigeria to assess the variation within these species. Maize, mucuna and lablab were included at these sites. The results are discussed in the context of soil nutrient depletion due to removal of nutrient elements in harvested seed and stover. The contribution of seed and stover removal to the proton (H+) budget and acidification of the soil is also discussed. It is estimated that the quantity of lime required to neutralize the acidity resulting from the removal of 1 t seed is 28 kg for soybean, 14 kg for cowpea and 5 kg for maize. The corresponding values for stover were soybean 35, cowpea 24 and maize 26 kg lime t−1 stover. Given the soil pH buffer capacity at the Ibadan site for the surface 16 cm, the yields obtained and assuming that seed and crop residues are removed, carbon cycle acidification would lead to a fall of 1 pH unit after 75 crops for soybean, 114 crops for cowpea and 68 crops for maize. The inclusion of legumes in cropping systems to increase N supply, and the use of P fertilizer to maximize N-fixation by legumes will raise production, but will inevitably accelerate removal of alkalinity and nutrients in harvested products, and the consequent decline in soil fertility. The data presented in this paper can be used in estimating the lime and fertilizer nutrients needed to maintain soil fertility and sustain yields
Genotypic variation for phosphorus uptake and dinitrogen fixation in cowpea on low-phosphorus soils of southern Cameroon
(Wiley, 2006) Jemo Martin; Abaidoo R. C; Nolte Christian; Horst Walter J.
In cowpea, efficient N2-fixing genotypes are being selected to promote sustainable cropping systems in southern Came roon (SC). However, N2 fixation and growth of these geno types are largely hampered by low levels of soil plant-avail able P. To evaluate the genotypic variation in N2 fixation and P uptake among cowpea (Vigna unguiculata L.) genotypes, field experiments were conducted over two years on two acid soils low in available P. The experiments were laid out in a split-block design with four replications on typic (TK) and rhodic (RK) Kandiudult soils with seven cowpea genotypes. Phosphorus (P) fertilizers were applied on the main plots with 0 kg P, 30 kg P ha–1 as triple superphosphate (TSP) and 90 kg P ha–1 as Togo phosphate rock (PR). Nodule dry matter(DM), shoot DM, grain yield, and P uptake of cowpea significantly varied with site, P application, and genotype (p < 0.05). The N2 fixation of the cowpea genotypes ranged from 29 to 51 kg N ha–1 on both TK and RK soils and was sig nificantly increased with P application. Significant genotypic variations in N2 fixation were observed with superior ability of the genotypes IT89KD-391 and IT90K-59 to fix N2. The harvest index (HI) did not significantly differ between soils and P application levels (p > 0.05). Four genotypes were selected to investigate root mechanisms responsible for effi cient P acquisition in pot experiments. The results suggest that a better root infection by arbuscular mycorrhizal fungi (AMF) in genotype IT90K-59 and root morphological and phy siological characteristics in IT89KD-391 were the most impor tant factors for inc
Injecting commercial sense into penal enactment: A Critique of the Fines (Penalty Units) Act, 2000 (Act 572).
(KNUST Law Journal, 2006) Owusu-Dapaa, E.
For a very long time the draftsman has been saddled with the problem of couching penal enactments. The problem that has often exercised the mind of the draftsman is mainly two-fold. First, it is pretty difficult getting the right and all embracing language that can capture various scenarios falling within the scope of the enactment. Sometimes over enthusiasm on the part of the draftsman to adopt an all embracing language with sufficient width to encapsulate all conceivable situations in the context of the enactment leads to the adoption of open textured language which is often fraught with vagueness and ambiguity that eventually gives rise to interpretation prob- lems. A typical instance of this problem is the Section 179A of the Crimi- nal Code (Amendment) Act, 1993 (Act 458)2.
Boosting of Cellular Immunity against Mycobacterium tuberculosis and Modulation of Skin Cytokine Responses in Healthy Human Volunteers by Mycobacterium bovis BCG Substrain Moreau Rio de Janeiro Oral Vaccine
(American Society for Microbiology, 2006-01-23) Cosgrove, Catherine A.; Castello-Branco, Luiz R. R.; Hussell, Tracy; Sexton, Amy; Giemza, Rafaela; et.al
Oral immunization of healthy adults with 107 CFU BCG Moreau Rio de Janeiro was well tolerated and significantly boosted gamma interferon responses to purified protein derivative, Ag85, and MPB70 from previous childhood intradermal BCG immunization. Oral BCG offers the possibility of a needle-free tuberculosis vaccine and of boosting the protective immunity from intradermal tuberculosis vaccines.
Cytokine Response to Antigen Stimulation of Whole Blood from Patients with Mycobacterium ulcerans Disease Compared to That from Patients with Tuberculosis
(American Society for Microbiology, 2006-02) Phillips, Richard Odame; Horsfield, C.; Kuijper, S.; Sarfo, Fred Stephen; Obeng-Baah, J.; et.al
Mycobacterium ulcerans disease (Buruli ulcer) is a skin-ulcerating infection common in some parts of the tropics. We have investigated cytokine secretion after stimulation of whole blood from Buruli ulcer (BU) patients in a region of endemicity in Ghana with M. ulcerans sonicate or culture filtrate antigens to investigate the development of the response over time and its specificity by comparison with the response to Mycobacterium tuberculosis sonicate in human immunodeficiency virus-negative tuberculosis patients. Significant gamma interferon (IFN- ) production in response to whole-blood stimulation with M. ulcerans sonicate was detected in patients with ulcers, which was higher than that in patients with nodules but similar to subjects with healed BU. The mean IFN- response in household contacts of BU patients was not significantly different from that in healthy control subjects from an area of nonendemicity. Results in patients with untreated, smear-positive pulmonary tuberculosis and tuberculosis patients on treatment for more than 2 weeks showed that BU patients responded better to M. ulcerans antigens than tuberculosis patients. In contrast, interleukin-10 results were higher in patients with active M. ulcerans disease than in those with healed lesions, but the pattern of response was similar to that seen in tuberculosis. A similar pattern of cytokine secretion was found using M. tuberculosis sonicate as an antigen. Neither of the two culture filtrate antigens of M. ulcerans appeared to be more specific than M. ulcerans sonicate. In the early stages of M. ulcerans disease there was a mixed Th1 and Th2 cytokine response, but the Th1 response emerged as the dominant type.

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