ghanaopendata/ghanaian-research-english huggingface dataset:
Human T cell recognition of polymorphic epitopes from malaria circumsporozoite protein

Lymphocytes obtained from forty individuals living in a malaria endemic area of West Africa were tested for in vitro proliferative responses to peptides representing variant regions of the immunodominant T cell domain of the circumsporozoite protein (amino acids 326 to 345, referred to as Th2R, and 361 to 380, referred to as Th3R) from three distinct strains of Plasmodium falciparum. A total of 83% of the individuals responded to at least one of the six peptides tested, confirming that these epitopes are immunodominant. A much greater number of individuals than expected by chance (32% of the responders to Th2R and 27% of the responders to Th3R) reacted to all three of the variant peptides for that epitope, indicating interdependency of the T cell responses, suggestive of cross-reactivity. Nevertheless, some subjects' T cells were clearly able to distinguish each variant peptide from the others. Using EBV transformed B cells, lymphocytes from 10 of the individuals were HLA typed. In this small group, HLA DRw13 was associated with a positive response to any of the peptides, whereas there was a negative association between DQw3 and response to any of the peptides. These results, although limited by the small sample size, suggest that recognition of T epitopes may be Ir gene linked. Our findings suggest that it may be possible to broaden the immunogenicity of an anti-sporozoite malaria vaccine.

Source: UG
Human T clones reactive to the sexual stages of plasmodium falciparum malaria. high frequency of gamete-reactive T cells in peripheral blood from nonexposed donors

Malarial gametocytes, which are taken up by mosquitoes during a blood meal, develop in the gut of the mosquito into gametes. Gametes and gametocytes contain the target antigens of transmission-blocking immunity. Here, we show that the peripheral blood of nonexposed donors contains Plasmodium falciparum gamete-reactive T cells at frequencies ranging from 1/300 to 1/4000. Studies on long-term clones demonstrated that these cells often recognized antigens shared between gametes and asexual stage parasites or even between heterologous gametes, although it has been possible to derive a P. falciparum gamete-specific T clone. The T clones examined were T3+, T4+, T8-, and either HLA-DR- or HLA-DQ-restricted. They responded to gametes by both proliferation and the secretion of γ-interferon. The gamete-specific clone and other asexual cross-reactive clones examined could be stimulated in vitro by a preparation of mature gametocytes within RBC, but not by RBC alone, suggesting that gametocytes are immunogenic or can become immunogenic for T cells in vivo. The significance of these observations to mosquito transmission of malaria and development and application of a gamete vaccine are discussed.

Source: UG
Human T-cell recognition of synthetic peptides representing conserved and variant sequences from the merozoite surface protein 2 of plasmodium falciparum

Merozoite surface protein 2 (MSP2) is a malaria vaccine candidate currently undergoing clinical trials. We analyzed the peripheral blood mononuclear cell (PBMC) response to synthetic peptides corresponding to conserved and variant regions of the FCQ-27 allelic form of MSP2 in Ghanaian individuals from an area of hyperendemic malaria transmission and in Danes without exposure to malaria. PBMC from 20-39% of Ghanaians responded to each of the peptides by proliferation and 29-36% had PBMC which produced interferon-gamma (IFN-gamma) in response to peptide stimulation. In Danes, there was no proliferation to two of the peptides and only PBMC from 5% of the individuals proliferated to the other three peptides. IFN-gamma production was not detected to any peptide. In both Danes and Ghanaians in only a few instances was IL-4 detected in the PBMC cultures. Overall PBMC from 79% of the Ghanaians responded by proliferation and/or cytokine secretion to at least one of three peptides tested, whereas responses were only observed in 14% of Danes (P = 0.002). These data suggest that the Ghanaians had expanded peripheral blood T-cell populations recognizing the peptides as a result of natural infection. The findings are encouraging for the development of a vaccine based on these T-epitope containing regions of MSP2, as the peptides were broadly recognized suggesting that they can bind to diverse HLA alleles and also because they include conserved MSP2 sequences. Immunisation with a vaccine construct incorporating the sequences present in these peptides could thus be expected to be immunogenic in a high percentage of individuals and lead to the establishment of memory T-cells, which can be boosted through natural infection.

Source: UG
Human T-cell recognition of the circumsporozoite protein of plasmodium falciparum: Immunodominant T-cell domains map to the polymorphic regions of the molecule

The definition of human T-cell antigenic sites is important for subunit vaccine development of a peptide immunogen if the goal is to allow antibody boosting during infection or to stimulate antibody-independent T-cell immunity. To identify such sites on the circumsporozoite (CS) protein of Plasmodium falciparum, 29 overlapping synthetic peptides spanning the entire CS protein were made and tested for their ability to stimulate peripheral blood lymphocytes from 35 adults living in a P. falciparum malaria-endemic region of West Africa. Three immunodominant domains were located outside the repetitive region. These domains, however, occurred in the polymorphic regions of the molecule, suggesting that parasite mutation and selection has occurred in response to immune pressure from T cells. Such polymorphism may impose an obstacle for vaccine development.

Source: UG
Human T-lymphotropic type-1 virus specific antibody detected in sera of HIV/AIDS patients in Ghana.

Serum samples from 124 acquired immunodeficiency syndrome (AIDS) hospitalized patients at the Fevers Unit, Korle-Bu Teaching Hospital, Accra, Ghana, were examined by the particle agglutination test for antibodies to human T-lymphotropic virus type 1 (HTLV-1) core proteins. The subjects included 84 males and 40 females, aged 16 to 54 years. Specific antibodies were detected in only 14 out of the 124 sera samples, giving an overall prevalence rate of 11.29%. The incidence was lower in males (5.95%; 5/84) than in females (22.50%; 9/40) (P<0.05). In both sexes, the age distribution of subjects positive for HTLV-1 antibodies ranged from 35 to 54 years. The prevalence rate reported herein is too low to suggest an association of HTLV-1 with AIDS, though it may indicate an opportunistic infection of AIDS patients by HTLV-1. Whether HTLV-1 is an underlying disease association or whether HTLV-1 plays some auxiliary role in the acquisition and progression of AIDS remains to be determined.

Source: UG
Human Vδ1+ T Cells in the Immune Response to Plasmodium falciparum Infection

Naturally acquired protective immunity to Plasmodium falciparum malaria is mainly antibody-mediated. However, other cells of the innate and adaptive immune system also play important roles. These include so-called unconventional T cells, which express a γδ T-cell receptor (TCR) rather than the αβ TCR expressed by the majority of T cells—the conventional T cells. The γδ T-cell compartment can be divided into distinct subsets. One expresses a TCR involving Vγ9 and Vδ2, while another major subset uses instead a TCR composed of Vδ1 paired with one of several types of γ chains. The former of these subsets uses a largely semi-invariant TCR repertoire and responds in an innate-like fashion to pyrophosphate antigens generated by various stressed host cells and infectious pathogens, including P. falciparum. In this short review, we focus instead on the Vδ1 subset, which appears to have a more adaptive immunobiology, but which has been much less studied in general and in malaria in particular. We discuss the evidence that Vδ1+ cells do indeed play a role in malaria and speculate on the function and specificity of this cell type, which is increasingly attracting the attention of immunologists.

Source: UG
Humans as Animal Sentinels for Forecasting Asthma Events

The concept of forecasting asthma using humans as animal sentinels is uncommon. This study explores the plausibility of predicting future asthma daily admissions using retrospective data in London (2005-2006). Negative binomial regressions were used in modeling; allowing the non-contiguous autoregressive components. Selected lags were based on partial autocorrelation function (PACF) plot with a maximum lag of 7 days. The model was contrasted with naïve historical and seasonal models. All models were cross validated. Mean daily asthma admission in 2005 was 27.9 and in 2006 it was 28.9. The lags 1, 2, 3, 6 and 7 were independently associated with daily asthma admissions based on their PACF plots. The lag model prediction of peak admissions were often slightly out of synchronization with the actual data, but the days of greater admissions were better matched than the days of lower admissions. A further investigation across various populations is necessary.

Source: UG
Humoral immune response to Epstein-Barr virus antigens and immunoglobulin allotypes in African Burkitt lymphoma patients.

Most research activities involve the use of molecular methods such as regular PCR (PCR), quantitative PCR (Q-PCR), genomic sequence and analysis using different software, genetic engineering, probe hybridization techniques, biological and molecular cloning, evaluation of immune markers for laboratory diagnosis of infections, serological assays involving the use of rapid tests, ELISA-based evaluations and immunofluorescent assay techniques.

Source: UG
Humoral immune response to mixed PfAMA1 alleles; multivalent PfAMA1 vaccines induce broad specificity

The Department of Immunology conducts research in the field of immunology of infectious and non-infectious diseases. The Department has the overall goal of contributing knowledge to better diagnosis, management, control and prevention of infectious and non-infectious diseases in Ghana and worldwide. This is consistent with the overall strategy of the Noguchi Memorial Institute for Medical Research (NMIMR) and in line with the strategy of the College of Health Sciences of the University of Ghana.

Source: UG
Humoral responses to plasmodium falciparum blood-stage antigens and association with incidence of clinical malaria in children living in an area of seasonal malaria transmission in Burkina Faso, West Africa.

There is longstanding evidence that immunoglobulin G (IgG) has a role in protection against clinical malaria, and human antibodies of the cytophilic subclasses are thought to be particularly critical in this respect. In this cohort study, 286 Burkinabè children 6 months to 15 years old were kept under malaria surveillance in order to assess the protective role of antibody responses against four antigens which are currently being evaluated as vaccine candidates: apical membrane antigen 1 (AMA1), merozoite surface protein 1-19 (MSP1-19), MSP3, and glutamate-rich protein (GLURP). Total IgG, IgM, and IgG subclass responses were measured just before the malaria transmission season. The incidence of malaria was 2.4 episodes per child year of risk. After adjusting for the confounding effects of age, the level of total IgG to GLURP was strongly associated with reduced malaria incidence (incidence rate ratio associated with a doubling of total IgG, 0.79; 95% confidence interval, 0.66 to 0.94; P = 0.009.); there was a borderline statistically significant association between the level of total IgG to MSP3 and malaria incidence and no evidence of an association for total IgG to AMA1 and to MSP1-19. Of the IgG subclass responses studied, only IgG3 and IgG4 against GLURP and IgG1 against AMA1 were associated with reduced risk of clinical malaria. There was no evidence of an interaction between responses to AMA1 and baseline parasitemia in their effects on malaria incidence. Currently included in malaria vaccine formulations for clinical trials in humans, these blood-stage antigens, AMA1 and GLURP, offer good prospects for malaria vaccine development. Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Source: UG
Humour in foreign Language Teaching, In: Journal “Practice and Theory in Systems of Education (P.T.S.E.)” ISSN 1788-2591 (Online), ISSN 1788-2583 (Printed) Vol. 6, Number 4 2011, Budapest, Hungary. pp. 327-336.

In this work we discuss humour and its uses in second language teaching citing examples from some European and African languages,more specifically Russian and Ghanaian humours. Our analysissuggest that there exist a common thread running through culture and humour in foreign language teaching since understanding humour is knowledge of the culture of the studied language. We conclude that humours should be used in foreign language classes as teachingmaterial, especially at the advanced levels and should be one of the goals of teaching and learning. This is due largely to the motivational role that it plays in the teaching process. The type of humour to use in the teaching process depends on the level, age, culture of the learners as well as the pedagogical goals. For different traditions and countries there is different sense of humour. Although, there are some similarities in Russians and Ghanaians humour, many cross cultural humour differences can be observed in these cultures. A major challenge encountered in the use of humour in the teaching process is the sense of humour of the learner and inadequate knowledge of the culture of the studies language. General and specific recommendations aimed at finding out how and what kinds of humour can be used in foreign language teaching are also made.

Source: UG
Hundred Years of Muslim Community in Accra: A Historical Study of Tudu from 1900-2000.

This is a chapter in a book entitled Islam in Africa South of the Sahara: Essays in Gender Relations and Political Reform. The book draws together contributions from scholars that focus on changes taking place in the practice of the religion and their effects on the political terrain and civil society. The chapter on a hundred years of Muslims in Accra, discussed the contribution of Muslims to Accra’s urban and economic development.

Source: UG
Hunting and consumption of rodents by children in the Lassa fever endemic area of Faranah, Guinea

As a consequence of the Ebola outbreak, human–animal contact has gained importance for zoonotic transmission surveillance. In Faranah (Upper Guinea), daily life is intertwined with rodents, such as the Natal multimammate mouse, Mastomys natalensis; a reservoir for Lassa virus (LASV). However, this contact is rarely perceived as a health risk by residents, although Lassa fever (LF) is known to be endemic to this region. Conversely, these observations remain a great concern for global health agendas. Drawing on ethnographic research involving interviews, focus group discussions, participant observations, and informal discussions over four months, we first identified factors that motivated children to hunt and consume rodents in Faranah villages, and thereafter, explored the knowledge of LF infection in children and their parents. Furthermore, we studied two dimensions of human-rodent encounters: 1) space-time of interaction and 2) factors that allowed the interaction to occur and their materiality. This approach allowed us to contextualize child-rodent contacts beyond domestic limits in the fallow fields, swamps, and at other times for this practice. A close look at these encounters provided information on rodent trapping, killing, and manipulation of cooking techniques and the risk these activities posed for the primary transmission of LASV. This research facilitated the understanding of children’s exposure to M. natalensis during hunting sessions and the importance of rodent hunting, which is a part of their boyish identity in rural areas. Determination of when, where, why, and how children, rodents, and environments interacted allowed us to understand the exposures and risks important for human and animal surveillance programs in the Lassa-endemic region.

Source: UG
Hunting intensity in the suhuma forest reserve in the sefwi wiawso district of the western region of ghana: A threat to biodiversity conservation

Hunting intensity in the Suhuma Forest Reserve (SFR) in the Sefwi Wiawso District of the Western Region of Ghana has been investigated. The methodology involved the recording of signs of hunting activity using linetransects, and interviews with hunters. A total of 157 spent cartridges, 21 wire snares, presence of 17 hunters, four hunting camps, and two gunshots were recorded over a total of 14 km of transects walked. Ten species of mammals were hunted, notably the brush-tailed porcupine (Atherurus africanus), Pel's flying squirrel (Anomalurus peli), long-tailed pangolin (Uromanis tetradactyla), giant rat (Cricetomys gambianus), Maxwell's duiker (Cephalophus maxwelli), bushbuck (Tragelaphus scriptus), bay duiker (Cephalophus dorsalis), royal antelope (Neotragus pygmaeus), western tree hyrax (Dendrohyrax dorsalis), and grasscutter (Thryonomys swinderianus). Wire snares and shotguns were the two main hunting methods employed, the former being used by all, and the latter by 34% of the hunters interviewed. Between 60 and 200 wire traps were set by each hunter. The results indicated a high hunting intensity in the Suhuma Forest Reserve. Some corrective measures have been recommended to ameliorate the problem. These measures include the initiation of public education and awareness programmes, establishment of task forces to check bushmeat hunting, execution of stricter law enforcement, and more punitive sanctions for offenders.

Source: UG
Hybrid Feature-Based Disease Detection in Plant Leaf Using Convolutional Neural Network, Bayesian Optimized SVM, and Random Forest Classifier

Plant diseases are unfavourable factors that cause a significant decrease in the quality and quantity of crops. Experienced biologists or farmers often observe plants with the naked eye for disease, but this method is often imprecise and can take a long time. In this study, we use artificial intelligence and computer vision techniques to achieve the goal of designing and developing an intelligent classification mechanism for leaf diseases. This paper follows two methodologies and their simulation outcomes are compared for performance evaluation. In the first part, data augmentation is performed on the PlantVillage data set images (for apple, corn, potato, tomato, and rice plants), and their deep features are extracted using convolutional neural network (CNN). These features are classified by a Bayesian optimized support vector machine classifier and the results attained in terms of precision, sensitivity, f-score, and accuracy. The above-said methodologies will enable farmers all over the world to take early action to prevent their crops from becoming irreversibly damaged, thereby saving the world and themselves from a potential economic crisis. The second part of the methodology starts with the preprocessing of data set images, and their texture and color features are extracted by histogram of oriented gradient (HoG), GLCM, and color moments. Here, the three types of features, that is, color, texture, and deep features, are combined to form hybrid features. The binary particle swarm optimization is applied for the selection of these hybrid features followed by the classification with random forest classifier to get the simulation results. Binary particle swarm optimization plays a crucial role in hybrid feature selection; the purpose of this Algorithm is to obtain the suitable output with the least features. The comparative analysis of both techniques is presented with the use of the above-mentioned evaluation parameters.

Source: UG
A Hybrid Heuristic Model for Duty Cycle Framework Optimization

This paper proposes a hybrid metaheuristic approach to optimize a duty cycle framework based on Seagull and Mayfly Optimization (HSMO-DC) Algorithm. This approach becomes crucial as current clustering protocols are unable to efficiently tune the clustering parameters in accordance to the diversification of varying WSNs. The proposed HSMO-DC primarily has two parts, where the first part takes care of the online cluster head selection and network communication using the seagull algorithm while the second part performs parameter optimization using the mayfly algorithm. The seagull is aimed at improving the energy distribution in the network through an effective bandwidth allocation procedure while reducing the total energy dissipation. Comparatively, with other clustering protocols, our proposed methods reveal an enhanced network lifetime with an improved network throughput and adaptability based on selected standard metric of performance measurement.

Source: UG
Hybridisation Of Institutional Logics And Civil Society Organisations' Advocacy In Kenya

Managerialist logic has become dominant in development policy and practice. However, in recent years, the Dutch government has seeking to adopt social transformation approaches to development interventions. The implementation of social Transformation ideas take place in an environment dominated by managerialism. However, our understanding of how the logic of social transformation and managerialism collide or come into conflict and the pathways through which managerialist principles dominate social transformation principles is limited. Drawing on qualitative data from the Strategic Partnerships (SP) and Accountability Fund (AF) policy instruments for civil society organisations in Kenya, we find that in practice, the social transformation principles underpinning the SP and AF ‘vaporise’ or get lost during implementation due to the wider aid system within which they are embedded. We highlight the implications of the broader aid system on attempts by donor agencies to shift from managerialism towards a social transformation perspective on development.

Source: UG