Showing papers by "University of Zimbabwe published in 2004"
Bradley University1, Pontifical Catholic University of Chile2, University of Tartu3, University of Louisville4, University of Latvia5, University of New Mexico6, Slovak Academy of Sciences7, University of San Carlos8, University of Malta9, Ghent University10, Clemson University11, University of Buenos Aires12, Osaka University13, Illinois State University14, National Autonomous University of Mexico15, University of Brasília16, University of Western Australia17, University of Lima18, Boğaziçi University19, University of Kassel20, University of York21, University of Queensland22, Åbo Akademi University23, Al Akhawayn University24, Indian Institute of Technology Kharagpur25, University of Hawaii at Manoa26, University of Catania27, University of Otago28, University of Dhaka29, Chemnitz University of Technology30, Knox College31, Comenius University in Bratislava32, University of Rijeka33, University of Malaya34, Vilnius University35, American University of Beirut36, Kwangju Health College37, University of Salzburg38, Utrecht University39, National Computerization Agency40, City University of Hong Kong41, University of Idaho42, University of Zimbabwe43, University of Lisbon44, University of Central Lancashire45, Loyola Marymount University46, University of Natal47, University of Granada48, University of Botswana49, University of Jordan50, Babeș-Bolyai University51, University of Cyprus52, University of Belgrade53, KPMG54, University of Montpellier55, University of Zurich56, University of Alabama57, Baylor University58, Queen's University Belfast59, University of Ljubljana60, University of Haifa61, University of La Serena62, Florida Atlantic University63, University of California, Davis64, University of Dar es Salaam65, Ramapo College66, Cyprus College67, Middle East Technical University68, University of the South Pacific69, VU University Amsterdam70, State University of New York System71, University of the Aegean72, Vrije Universiteit Brussel73, University of Lethbridge74, University of Vienna75, University of Hong Kong76, Yuan Ze University77, Charles University in Prague78, Chonnam National University79
TL;DR: In the International Sexuality Description Project, a total of 17,804 participants from 62 cultural regions completed the RelationshipQuestionnaire (RQ), a self-report measure of adult romantic attachment as discussed by the authors.
Abstract: As part of the International Sexuality Description Project, a total of 17,804 participants from 62 cultural regions completedthe RelationshipQuestionnaire(RQ), a self-reportmeasure of adult romanticattachment. Correlational analyses within each culture suggested that the Model of Self and the Model of Other scales of the RQ were psychometrically valid within most cultures. Contrary to expectations, the Model of Self and Model of Other dimensions of the RQ did not underlie the four-category model of attachment in the same way across all cultures. Analyses of specific attachment styles revealed that secure romantic attachment was normative in 79% of cultures and that preoccupied romantic attachment was particularly prevalent in East Asian cultures. Finally, the romantic attachment profiles of individual nations were correlated with sociocultural indicators in ways that supported evolutionary theories of romantic attachment and basic human mating strategies.
314 citations
TL;DR: In this paper, the effects of increasing concentration of potato waste expressed as percentage of total solids and the initial inoculum-to-substrate ratio (ISR) on methane yield and productivity were investigated.
278 citations
TL;DR: Data suggest that preferential targeting of Gag epitopes, rather than the breadth or magnitude of the response across the genome, may be an important marker of immune efficacy in vaccine-induced responses.
Abstract: An understanding of the relationship between the breadth and magnitude of T-cell epitope responses and viral loads is important for the design of effective vaccines. For this study, we screened a cohort of 46 subtype C human immunodeficiency virus type 1 (HIV-1)-infected individuals for T-cell responses against a panel of peptides corresponding to the complete subtype C genome. We used a gamma interferon ELISPOT assay to explore the hypothesis that patterns of T-cell responses across the expressed HIV-1 genome correlate with viral control. The estimated median time from seroconversion to response for the cohort was 13 months, and the order of cumulative T-cell responses against HIV proteins was as follows: Nef > Gag > Pol > Env > Vif > Rev > Vpr > Tat > Vpu. Nef was the most intensely targeted protein, with 97.5% of the epitopes being clustered within 119 amino acids, constituting almost one-third of the responses across the expressed genome. The second most targeted region was p24, comprising 17% of the responses. There was no correlation between viral load and the breadth of responses, but there was a weak positive correlation (r = 0.297; P = 0.034) between viral load and the total magnitude of responses, implying that the magnitude of T-cell recognition did not contribute to viral control. When hierarchical patterns of recognition were correlated with the viral load, preferential targeting of Gag was significantly (r = 0.445; P = 0.0025) associated with viral control. These data suggest that preferential targeting of Gag epitopes, rather than the breadth or magnitude of the response across the genome, may be an important marker of immune efficacy. These data have significance for the design of vaccines and for interpretation of vaccine-induced responses.
228 citations
TL;DR: In this article, the authors explore the tradeoffs between the level of competition and the degree of coordination achieved between players within a cotton sector in Ghana, Mozambique, Tanzania, Uganda, Zambia and Zimbabwe.
220 citations
TL;DR: Widespread intraplate magmatism during Rodinia assembly shows that mantle upwellings required to generate such provinces may occur independently of the supercontinent cycle.
Abstract: We show that intraplate magmatism occurred 1106 to 1112 million years ago over an area of two million square kilometers within the Kalahari craton of southern Africa, during the same magnetic polarity chron as voluminous magmatism within the cratonic core of North America. These contemporaneous magmatic events occurred while the Rodinia supercontinent was being assembled and are inferred to be parts of a single large igneous province emplaced across the two cratons. Widespread intraplate magmatism during Rodinia assembly shows that mantle upwellings required to generate such provinces may occur independently of the supercontinent cycle.
186 citations
TL;DR: In this article, the double hurdle model is used to analyse the off-farm labour decisions of small-scale agricultural household members in the Shamva District of Zimbabwe, and the approach permits the joint modelling of the decision to participate in the labour market and the decision regarding the amount of time allocated to work.
176 citations
TL;DR: The results show that participation in local community groups is often positively associated with successful avoidance of HIV, which, in turn, is positive associated with psychosocial determinants of safer behaviour, and suggest that promotion of and organisational development and training among community groups could well be an effective HIV control strategy.
159 citations
TL;DR: In its traditional or new form, antenatal care ignores the experiences and views of women and the way they make sense of pregnancy and the care of pregnancy, it is concluded.
157 citations
TL;DR: In this article, the authors present an integrated approach to agricultural water management, analysing the interactions between the adoption and participatory adaptation of water system innovations (such as water harvesting, drip irrigation, conservation farming, etc.), increased water use in agriculture and water flows to sustain ecological functions that deliver critical ecosystem services to humans.
Abstract: The challenge of producing food for a rapidly increasing population in semi-arid agro-ecosystems in Southern Africa is daunting. More food necessarily means more consumptive use of so-called green water flow (vapour flow sustaining crop growth). Every increase in food production upstream in a watershed will impact on water user and using systems downstream. Intensifying agriculture has in the past often been carried out with negative side effects in terms of land and water degradation. Water legislation is increasingly incorporating the requirement to safeguard a water reserve to sustain instream ecology. To address the challenges of increasing food production, improving rural livelihoods, while safeguarding critical ecological functions, a research programme has recently been launched on “Smallholder System Innovations in Integrated Watershed Management” (SSI). The programme takes an integrated approach to agricultural water management, analysing the interactions between the adoption and participatory adaptation of water system innovations (such as water harvesting, drip irrigation, conservation farming, etc.), increased water use in agriculture and water flows to sustain ecological functions that deliver critical ecosystem services to humans. The research is carried out in the Pangani Basin in Tanzania and the Thukela Basin in South Africa. A nested scale approach is adopted, which will enable the analysis of scale interactions between water management at the farm level, and cascading hydrological impacts at watershed and basin scale. This paper describes the integrated research approach of the SSI programme, and indicates areas of potential to upgrade rainfed agriculture in water scarcity-prone agro-ecosystems while securing water for downstream use.
147 citations
TL;DR: In this article, the authors used R-mode factor analysis to identify a chemical signature (nitrate and phosphate; minor iron) related to the sewage works, but this signature involved parameters that were within regulated limits, the finding was of limited value for management purposes.
Abstract: Although developed as a tool in the social sciences, R-mode factor analysis, a multivariate statistical tool, has proven highly effective in studies of groundwater quality. The technique examines the relationships between variables (such as chemical parameters in groundwater), which are shown by a number of cases (such as sampling points). In this study, two examples are presented. The first is of groundwater around a southern African iron ore mine and the second is of groundwater in the vicinity of a southern African municipal sewage disposal works. Groundwater samples were collected, their chemistry analysed and factor analysis was performed on each of the chemical datasets. In the first case study, factor analysis successfully separated signatures due to uncontaminated groundwater (calcium, magnesium and bicarbonate), agricultural activities (potassium and ammonium) and mining activities (sodium, chloride and sulphate). In the second case study, factor analysis did identify a chemical signature (nitrate and phosphate; minor iron) related to the sewage works—but since this signature involved parameters that were within regulated limits, the finding was of limited value for management purposes. Thus although R-mode factor analysis can be a valuable tool studies of groundwater quality, this is not always the case. Multivariate statistical techniques like factor analysis should thus be used as supplementary to, but not in replacement of, conventional groundwater quality data treatment methods.
139 citations
TL;DR: Pb baddeleyite crystallization ages of ~1927 and ~1879 to ~1872 Ma for dolerite sills intruding the Waterberg Group in Botswana and South Africa were reported in this article.
Abstract: We report U–Pb baddeleyite crystallization ages of ~1927 and ~1879 to ~1872 Ma for dolerite sills intruding the Waterberg Group in Botswana and South Africa. These data increase the known extent of ~1.9 Ga intraplate magmatism in southern Africa and place tighter age constraints on the Waterberg Group than previously available. In South Africa, ~1.88 Ga dolerite intrudes upper Waterberg strata, constraining most, if not all, of the succession to have accumulated between ~2.06 Ga (age of the underlying Bushveld Complex) and ~1.88 Ga. This is consistent with derivation of much of the group from uplifted sources in reactivated segments of the Limpopo Belt. The dolerites are typical continental tholeiites, but their trace-element contents discriminate them from dolerite sills of the 1.1 Ga Umkondo Igneous Province, which occur in the same region. Paleomagnetic samples from dolerite intrusions in the Waterberg Group in South Africa (including one sill with a U–Pb baddeleyite age of ~1872 Ma), and from dolerite sills and basalt flows in the Soutpansberg Group to the east-northeast, yield antipodal directions with a site mean pole at 15.6°north, 17.1°east, A95 = 8.9°. These data are interpreted to indicate that the ~1879 to ~1872 Ma dolerites were intruded into the Waterberg Group during voluminous magmatism associated with development of the Soutpansberg rift basin. Older, ~1927 Ma dolerite in Botswana is similar in age and geochemistry to basalts in the craton-margin Olifantshoek Supergroup, suggesting that the mafic magmatism in those two regions is genetically related.
TL;DR: In this paper, the authors investigated the production of volatile fatty acids by anaerobic digestion of solid potato waste using a batch solid waste reactor with a working capacity of 2 dm(-3) at 37degreesC.
Abstract: The production of volatile fatty acids by anaerobic digestion of solid potato waste was investigated using a batch solid waste reactor with a working capacity of 2 dm(-3) at 37degreesC. Solid potato waste was packed into the digester and the organic content of the waste was released by microbial activity by circulating water over the bed, using batch loads of 500g or 1000 g potato waste. The sequence of appearance of the volatile fatty acids was (acetic, propionic); (n-butyric); (n-valeric, iso-valeric, caproic); (iso-butyric). After 300 h digestion of potato waste on a small scale, the fermentation products were chiefly (mg g(-1) total VFAs): acetic acid (420), butyric acid (310), propionic acid (140) and caproic acid (90), with insignificant amounts of iso-butyric acid, n-valeric and iso-valeric acids. When the load of potato solids was increased, the volatile fatty acid content was similar, but butyric acid constituted 110 mg g(-1) and lactic acid 400 mg g(-1) of the total volatile fatty acids. The maximum soluble chemical oxygen demand (COD) achieved under the experimental conditions used was 27 and 37 g COD dm(-3) at low and high loadings of potato solids, respectively. The total volatile fatty acids reached 19 g dm(-3) of leachate at both loads of potato solid waste. Gas production was negligible, indicating that methanogenic activity was effectively inhibited. (C) 2004 Society of Chemical Industry. (Less)
TL;DR: The leaf oil of Heteropyxis dehniae Suess was obtained by hydrodistillation and analyzed by GC/MS and Caryophyllene oxide shows notable cytotoxic activity with LC50 values of 147-351 microM.
TL;DR: It was concluded that priming benefits result from improved crop stand and from advancement of germination and emergence of maize in semi-arid Zimbabwe.
TL;DR: It can be concluded that (1) improved legume fallow system results in net positive soil N balances, (2) despite large inputs of litter and continued recycling of N during the cropping phase, legume species that re-grow after cutting can result in depressed yields in drought seasons, and (3) tillage is beneficial even after improved legumes fallows.
Abstract: Three woody legumes were planted as two-year 'improved fallows' to evaluate their residual nitrogen (N) effects on two subsequent maize crops under minimum and conventional tillage management. Maize monoculture and cowpea-maize-maize sequence treatments were included as controls. N-2-fixation was estimated using the N-15 natural abundance method to allow the N contribution from the fallows to be partitioned into N2-fixation and soil N capture. Acacia angustissima accumulated the largest amount of both below-ground and above-ground biomass during the 2-year growth period. Using Hyparrhenia grass as the reference plant, the proportion of N-2-fixed in litter was 56, 55, 84 and 58% for Acacia, Sesbania sesban, Cajanus cajan, and cowpea, respectively, resulting in inputs of biologically fixed N of 122, 84, 96 and 28 kg N ha(-1). Maize growth following the legumes for two subsequent cropping seasons was in most cases not directly related to the N inputs. The first year maize crop was severely infested with cutworms (Agrotis sp.) in the Sesbania and Acacia plots, while the second season maize was affected by drought particularly in the Acacia plots where there was high moisture demand by the re-growing trees. During the second season, N uptake by maize following Sesbania was significantly higher than the rest of the treatments. Conventional tillage resulted in better yields than minimum tillage across all treatments and in both seasons. It can be concluded that (1) improved legume fallow system results in net positive soil N balances, (2) despite large inputs of litter and continued recycling of N during the cropping phase, legume species that re-grow after cutting can result in depressed yields in drought seasons, and (3) tillage is beneficial even after improved legume fallows.
TL;DR: It is proposed that termite mound construction in miombo woodland contributes to sustaining populations of megaherbivores and perhaps some woody species in these areas.
Abstract: Thirteen termite mounds and 13 similar-sized control plots were surveyed in central Zimbabwe in order to study large mammalian browsing and vegetation characteristics. The mounds supported almost twice as many tree species as the control plots and the woody vegetation was denser on mounds compared with the woodland plots. Species of woody plants were recorded along with the percentage of branches browsed (cumulative browsing score) by black rhino, Diceros bicornis, elephant, Loxodonta africana and other browsers combined. In addition we measured how the cumulative browsing score on three woody plant species, Acacia nilotica, Colophospermum mopane and Dichrostachys cinerea, which were common both on and off mounds, was related to the distance from mound centre. Both black rhino and elephant cumulative browsing scores were significantly higher on the mound plants compared with the woodland plots. Cumulative browsing score was negatively related to distance from the mound centre for Dichrostachys cinerea, Colophospermum mopane and Acacia nilotica. We propose that termite mound construction in miombo woodland contributes to sustaining populations of megaherbivores and perhaps some woody species in these areas.
TL;DR: In this paper, the authors evaluated and recommended rainwater harvesting techniques that ensure effective capture and utilization of rainfall for sustainable crop production, which was achieved through monitoring residual moisture, after every rainfall shower, in the different tillage treatments.
Abstract: The study was carried out at three sites in Communal Lands of Zimbabwe namely, Mudzi (Natural Region V), Gutu (Natural Region IV) and Chivi (Natural Region V). These areas have marginal rainfall in terms of quantities (below 500 mm per year) and distribution with a normal rainfall year coming once in every five years. Four tillage treatments were experimented on in the three sites. These were tied ridges, infiltration pits, fanya juus and the conventional ploughing on the flat. The tillage treatments were paired at farm level for easy management considering that farmers were participating in the research trials. The conventional tillage technique was used as control.
The objective of the study was to evaluate and recommend rainwater harvesting techniques that ensure effective capture and utilization of rainfall for sustainable crop production. This was achieved through monitoring residual moisture, after every rainfall shower, in the different tillage treatments. Monitoring of residual moisture was done, up to a depth of 30 cm, using a θ-probe. Yields of maize from the different tillage treatments were determined. Farmers also carried out their own evaluation of the treatments at mid-season and at the end of the season. In addition the researchers tested dissemination techniques that ensured maximum adoption of rainwater harvesting techniques.
Tied ridges were ranked best by both the stakeholders’ evaluation and the theta (θ)-probe in retaining moisture compared to all the other treatments in the season under consideration. The farmers who practiced tied ridges realized yields of about 3 t/ha compared to conventional tillage treatments whose yields were about 1.5 t/ha. Yields were statistically significantly different for the different treatments.
The recommendation was for the farmers to adopt the tied ridges in areas that receive marginal rainfall and experience mid-season droughts. Lead farmers should educate others on the advantages of the tillage treatments.
TL;DR: The land question in particular has been located within a discourse of legitimate redress for colonial injustice, language which has resonated on the African continent, and within the Third World more generally.
Abstract: There can be little doubt that one of the most significant aspects of the current crisis in Zimbabwe, especially the events of the past two or three years, has been its international character. At the heart of President Robert Mugabe's offensive against the array of forces opposed to his rule are repeated attempts to place the Zimbabwe problem at the centre of a larger anti-imperialist and Pan-African position. These tactics have been crucial to the process of legitimising the recent actions of ZANU-PF, in power since independence in 1980. The land question in particular has been located within a discourse of legitimate redress for colonial injustice, language which has resonated on the African continent, and within the Third World more generally. Knowing that his authoritarian rule would be confronted with a widespread national and international critique centred on property rights, human rights and the rule of law, Mugabe and his advisors constructed alternative discourses around the need for renewed lib...
TL;DR: In this article, the fate of added N on a sandy loam soil was determined in an improved fallow - maize sequence field experiment in Zimbabwe using soil augmentation in seven land use systems.
Abstract: The fate of the added N on a sandy loam soil was determined in an improved fallow - maize sequence field experiment in Zimbabwe. Pre-season mineral N was determined in 20 cm sections to 120 cm depth by soil auguring in seven land use systems. Thereafter, sequential soil auguring was done at two-week intervals in plots that previously had 2-year fallows of Acacia angustissima, Sesbania sesban and unfertilized maize to determine mineral N dynamics. Using the static chamber technique, N2O fluxes were also determined in the same plots. Pre-season NH4-N concentrations were > 12 kg N ha-1 in the 0-20 cm layer for treatments that had a pronounced litter layer. NO 3-N concentrations below 60 cm depth were 10 kg N ha-1 layer-1 in the control plots where maize had been cultivated each year. There was a flush of NO 3-N in the Sesbania and Acacia plots with the first rains. Topsoil NO3-N had increased to > 29 kg N ha-1 by the time of establishing the maize crop. This increase in NO3-N in the topsoil was not sustained as concentrations decreased rapidly within three weeks of maize planting, to amounts of 8.6 kg N ha-1 and 11.2 kg N ha -1 for the Sesbania and Acacia plots, respectively. Total NO 3-N leaching losses from the 0-40 cm layer ranged from 29-40 kg ha-1 for Sesbania and Acacia plots within two weeks when 104 mm rainfall was received to an already fully recharged soil profile. Nitrate then accumulated below the 40 cm depth during early season when the maize had not developed a sufficient root length density to effectively capture nutrients. At one week after planting maize, N2O fluxes of 12.3 g N2O-N ha-1 day-1 from Sesbania plots were about twice as high as those from Acacia, and about seven times the 1.6 g N2O-N ha -1 day-1 from maize monoculture. This was at the time when mineral N was at its peak in the topsoil. The unfertilized maize showed consistently low N2O emissions, which never exceeded 2 g N 2O-N ha-1 day-1 for all the eight sampling dates. The decrease of mineral N concentration in the topsoil resulted in reduced N2O fluxes, despite very high soil moisture conditions. Total N2O-N emissions were greatest for Sesbania plots with 0.3 kg ha -1 lost in 56 days. We conclude that, under high rainfall conditions, there is an inherent problem in managing mineral N originating from mineralization of organic materials as it accumulates at the onset of rains, and is susceptible to leaching before the crop root system develops. We did not quantify nitric oxide and N2 gas emissions, but it is unlikely that total gaseous N losses would be significant and contribute to poor N recovery that has been widely reported.
TL;DR: In these environments where biomass accumulation in many legumes is restricted by soil biophysical factors (poor nutrient concentrations, acidity, coarse texture), combinations of legume rotations and mineral N fertilization will remain the most viable option for sustainable agriculture.
TL;DR: A high prevalence of HPV was found in a rural community, where regular Papanicolaou (Pap) smears would be a logistic and economic impossibility, but where free vaccination programmes against other infections are already established, and the results suggest that HIV co‐infection may have an impact on HPV genotype distribution.
Abstract: Cervical cancer is a leading cause of cancer-related deaths in developing countries, and the human papillomavirus (HPV) is linked etiologically to cervical cancer. Hence, a vaccine which prevents HPV-associated cervical cancer would have the most impact in developing countries, including the African continent. The type-specific immune response towards HPV virus-like particles, in combination with geographical variation in the prevalence of HPV, necessitates the presence of multiple HPV type antigens in a single vaccine cocktail in order to provide relevant protection. We aimed to investigate whether co-infection with HIV, which is highly prevalent in Africa, plays a role in HPV genotype distribution. After informed consent, HPV detection by GP5+/6+ PCR and HIV detection by serology was carried out on 236 women from the rural north-western part of Zimbabwe. The prevalence of HPV was higher in HIV positive women (54%) than in HIV negative women (27%). Certain HPV types (HPV types 11, 39, 43, 51, and 59, P-values ranging from 0.017 to 0.067) occurred more frequently in HIV positive women. Only high-risk HPV, and not HIV, was associated significantly with cervical intraepithelial neoplasia in multiple regression analysis. In conclusion, a high prevalence of HPV was found in a rural community, where regular Papanicolaou (Pap) smears would be a logistic and economic impossibility, but where free vaccination programmes against other infections are already established. The results suggest that HIV co-infection may have an impact on HPV genotype distribution.
TL;DR: In the first 6 months of life, IU and IP/ePP transmission contributed more than three-quarters of the 30.7% MTCT and timing of infection, birth weight and maternal CD4 cell counts were important factors in predicting infant death.
Abstract: Objectives: To examine the risks of intra-uterine (IU) intra- and early post-partum (IP/ ePP) and late post-partum (LPP) mother-to-child transmission (MTCT) of HIV-1 and infant mortality in the first 6 months of life. Whole blood was collected in ethylenediaminetetra-acetic acid at birth 6 weeks 3 and 6 months from 996 infants born to HIV-1 seropositive mothers. Polymerase chain reaction using Roche DNA amplification assay version 1.5 was used to determine timing of MTCT. Logistic regression models determined risk factors for HIV-1 transmission and survival analyses examined mortality by timing of transmission. Two hundred and forty-nine mothers (30.7%) transmitted HIV-1 infection to their infants by 6 months of age. Eighty-nine infants [9.4%; 95% confidence interval (CI) 7.7–11.5] 104 infants (16.0%; 95% CI 10.8–21.2) and 21 infants (5.3%; 95% CI 1.6–12.2) were infected IU IP/ePP and LPP respectively. Low maternal CD4 cell count and arm circumference were risk factors for IP/ePP transmission. Infant mortality was higher among infected infants than uninfected (P 0.001 log rank test). Timing of infection birth weight and maternal CD4 cell counts were important factors in predicting infant death. In the first 6 months of life IU and IP/ePP transmission contributed more than three-quarters of the 30.7% MTCT. Our data in addition to serving as a historical comparison may be useful in designing and evaluating the efficacy of short course antiretroviral trials aimed at reducing MTCT in developing countries. (authors)
TL;DR: In this article, a method for evaluating criteria used to advise farmers on planting dates at the onset of the rainy season was presented, using an analysis of the relative transpiration rate (the ratio of the actual transpiration to the potential transpiration).
TL;DR: It appears from literature studied connection with these studies, that management, and thus production performance, in general is comparable in different countries and affected by similar factors.
Abstract: Formal knowledge about traditional free-range chicken production in tropical countries is increasing but still limited. However, it appears from literature studied connection with these studies, that management, and thus production performance, in general is comparable in different countries and affected by similar factors. Further, poultry production has shown to be a very important income generating activity, predominantly run by women. On the basis of three studies (A, B and C), the paper describes local chicken production in a communal area of Zimbabwe and highlights production characteristics. Study A is an investigation of the management and production through questionnaires and semi-structured interviews. Study B is a phenotypic description of 360 chickens and a description of feed availability. Study C is records of production during 6 months. Findings confirmed that women owned most chicken flocks and that income generated from chicken production was spent to better nutrition, health and education of the family. High mortality and slow growth were, by farmers perceived to be the major constraints to production. This was supported by production records, which showed that survival among young chickens was low (45% until 16 weeks of age). Most deaths (69%) occurred during the first 3 weeks after hatching. Most common mortality causes were diseases, predation, external parasites and accidents. Few clutches per hen per year with long brooding periods resulted in low production of chickens ready for slaughter or sale. Growth rates until 10 weeks of age were just over 6 g/day. Production results are discussed in relation to other literature.
TL;DR: In this paper, the authors highlight the fact that the country had a resettlement program for two decades before the large-scale, politically motivated land occupations began in 2000 and provide a historical bookmark for the earlier period of land reform in the hope that the lessons from that experience will not be lost.
TL;DR: In this paper, the authors measured the tree canopy architecture at six savanna sites on deep, sandy soils, along a gradient of increasing aridity, and found that the average tree canopy cover decreased from 50% to 20% over this aridity range, while the leaf area index within the area covered by tree canopies remained fairly constant at 3-4 m 2 m � 2.
Abstract: Measurements of tree canopy architecture were made at six savanna sites on deep, sandy soils, along a gradient of increasing aridity. There was substantial variation in the leaf area estimated within each site, using the same sample frame, but different measurement techniques. The trends in canopy properties in relation to the aridity gradient were consistent, regardless of the technique used for estimating the properties. The effective plant area index for the tree canopy (the sum of the stem area index and the leaf area index (LAI)) declined from around 2 to around 0.8 m 2 m � 2 over a gradient of mean annual rainfall from 1000 to 350 mm. Stems contributed 2–5% of the tree canopy plant area index. Since the tree canopy cover decreased from 50% to 20% over this aridity range, the leaf area index within the area covered by tree canopies remained fairly constant at 3–4 m 2 m � 2 . Tree leaves tended from a horizontal orientation to a more random orientation as the aridity increased. On the same gradient, the leaf minor axis dimension decreased from around 30 mm to around 3 mm, and the mean specific leaf area decreased from 14 to 5 m 2 kg ha � 1 . There was good agreement between LAI observed in the field using a line ceptometer and the LAI inferred by the MODIS sensor on the Terra satellite platform, 2 months later in the same season.
TL;DR: In this epidemiologically well characterized urban population with a high prevalence of HIV infection, a very high level of strain clustering is identified, indicating substantial ongoing recent TB transmission.
Abstract: We examined the pattern of tuberculosis (TB) transmission (i.e., reactivation versus recent transmission) and the impact of human immunodeficiency virus (HIV) infection in Harare, Zimbabwe. Consecutive adult smear-positive pulmonary TB patients presenting to an urban hospital in Harare were enrolled. A detailed epidemiological questionnaire was completed, and tests for HIV type 1 and CD4 cell counts were performed for each patient. Molecular fingerprinting of the genomic DNA recovered from cultures of sputum was performed by two molecular typing methods: spacer oligonucleotide typing (spoligotyping) and analysis of variable number of tandem DNA repeats (VNTRs). A cluster was defined as isolates from two or more patients that shared the same spoligotype pattern or the same VNTR pattern, or both. DNA suitable for typing was recovered from 224 patients. The prevalence of HIV infection was 79%. Of 187 patient isolates (78.6%) typed by both spoligotyping and analysis of VNTRs, 147 were identified as part of a cluster by both methods. By spoligotyping alone, 84.1% of patient isolates were grouped into 20 clusters. The cluster size was generally <8 patient isolates, although three large clusters comprised 68, 25, and 23 patient isolates. A total of 89.4% of the patient isolates grouped into 12 clusters defined by analysis of VNTRs, with 2 large clusters consisting of 127 and 13 patient isolates, respectively. Thirty-six percent of patient isolates with a shared spoligotype and 17% with a shared VNTR pattern were geographically linked within Harare, but they were not linked on the basis of the patient's home district. In a multivariate analysis, there were no independent predictors of clustering, including HIV infection status. Comparison with the International Spoligotype database (Pasteur Institute, Pointe a Pitre, Guadeloupe) demonstrated that our three largest spoligotype clusters are well recognized and ubiquitous in Africa. In this epidemiologically well characterized urban population with a high prevalence of HIV infection, we identified a very high level of strain clustering, indicating substantial ongoing recent TB transmission. Geographic linkage could be detected in a proportion of these clusters. A small group of actively circulating strains accounted for most of the cases of TB transmission.
TL;DR: Race specific comparisons to cancer patients in the United States show thatimbabwean patients have much lower survival than American cancer patients and that the gap between black Zimbabwean patients and black American patients is broader than between white Zimbabwean and white American patients.
Abstract: This paper provides the first comprehensive population based cancer survival estimates from the African continent. Five-year absolute and relative survival estimates are presented for black and white Zimbabwean patients diagnosed with cancer in Harare, Zimbabwe between the years 1993 and 1997. The survival of black Zimbabwean cancer patients are among the lowest ever reported from population based cancer registries. For most cancer sites, white Zimbabwean patients have much higher survival than black Zimbabweans, except for lung and colorectal cancer, for which the estimates are similarly poor. Race specific comparisons to cancer patients in the United States show that Zimbabwean patients have much lower survival than American cancer patients and that the gap between black Zimbabwean patients and black American patients is broader than between white Zimbabwean and white American patients. Access to and the ability to pay for medical care may be a very important barrier to better survival for the majority of black Zimbabwean patients and the most important cause for the very low cancer survival in this population.
TL;DR: Hepatosplenic disease in school‐aged children attributable to S. mansoni infection, involving hepatosplenomegaly and increased portal vein diameter, can occur in the absence of peri‐portal fibrosis.
Abstract: Hepatosplenic schistosomiasis involving organomegaly, portal fibrosis and portal hypertension has been observed in autopsy studies. Here, we have tested the hypothesis that hepatosplenic disease including organomegaly and markers of increased portal pressure can occur in school aged children in the absence of fibrosis. A case-only study of 96 children aged 7-20 years defined by ultrasound detectable hepatomegaly was undertaken in Makueni district, Kenya. A novel method of clinical examination that involved a consensus scoring by three or four examiners was used to classify children as presenting with severe or moderate hepatosplenic disease after palpation of livers and spleens. Ultrasound examination of livers and spleens was based on the Niamey protocol. Clinical measurements included spleen enlargement along the mid-clavicular and mid-axillary lines, liver enlargement along the mid-sternal (MSL) and mid-clavicular lines, as well as organ consistency. The clinical examination indicated that 9% and 60% of the children had severe or moderate hepatosplenomegaly, respectively. Amongst egg-positive children, all clinical measurements, except MSL liver enlargement, correlated with egg count, as did portal vein diameter, spleen length and liver length measured by ultrasound. Peri-portal fibrosis was not observed in any child, whereas 28% of the children were classified as having increased portal pressure according to World Health Organization criteria. There was no effect of malaria parasitaemia or hepatitis seropositvity on any of the observed parameters. These results indicate that hepatosplenic disease in school-aged children attributable to S. mansoni infection, involving hepatosplenomegaly and increased portal vein diameter, can occur in the absence of peri-portal fibrosis.
TL;DR: Five of nine identified optimal Gag epitopes were novel and restricted by unique HLA, and they overlapped or were embedded within previously described CTL epitopes from subtype B HIV-1 infection.
Abstract: Characterization of optimal CTL epitopes in Gag can provide crucial information for evaluation of candidate vaccines in populations at the epicenter of the HIV-1 epidemic. We screened 38 individuals with recent subtype C HIV-1 infection using overlapping consensus C Gag peptides and hypothesized that unique HLA-restricting alleles in the southern African population would determine novel epitope identity. Seventy-four percent of individuals recognized at least one Gag peptide pool. Ten epitopic regions were identified across p17, p24, and p2p7p1p6, and greater than two-thirds of targeted regions were directed at: TGTEELRSLYNTVATLY (p17, 35%); GPKEPFRDYVDRFFKTLRAEQATQDV (p24, 19%); and RGGKLDKWEKIRLRPGGKKHYMLKHL (p17, 15%). After alignment of these epitopic regions with consensus M and a consensus subtype C sequence from the cohort, it was evident that the regions targeted were highly conserved. Fine epitope mapping revealed that five of nine identified optimal Gag epitopes were novel: HLVWASREL, LVWASRELERF, LYNTVATLY, PFRDYVDRFF, and TLRAEQATQD, and were restricted by unique HLA-Cw*08, HLA-A*30/B*57, HLA-A*29/B*44, and HLA-Cw*03 alleles, respectively. Notably, three of the mapped epitopes were restricted by more than one HLA allele. Although these epitopes were novel and restricted by unique HLA, they overlapped or were embedded within previously described CTL epitopes from subtype B HIV-1 infection. These data emphasize the promiscuous nature of epitope binding and support our hypothesis that HLA diversity between populations can shape fine epitope identity, but may not represent a constraint for universal recognition of Gag in highly conserved domains.