ghanaopendata/ghanaian-research-english huggingface dataset:
Plasmodium falciparum strains spontaneously switch invasion phenotype in suspension culture

The extensive redundancy in the use of invasion ligands by Plasmodium falciparum, and its unique ability to switch between invasion pathways have hampered vaccine development. P. falciparum strains Dd2 and W2mef have been shown to change from sialic acid (SA)-dependent to SA-independent phenotypes when selected on neuraminidase-treated erythrocytes. Following an observation of increasing ability of Dd2 to invade neuraminidase-treated cells when cultured for several weeks, we systematically investigated this phenomenon by comparing invasion phenotypes of Dd2, W2mef and 3D7 strains of P. falciparum that were cultured with gentle shaking (Suspended) or under static (Static) conditions. While Static Dd2 and W2mef remained SA-dependent for the entire duration of the investigation, Suspended parasites spontaneously and progressively switched to SA-independent phenotype from week 2 onwards. Furthermore, returning Suspended cultures to Static conditions led to a gradual reversal to SA-dependent phenotype. The switch to SA-independent phenotype was accompanied by upregulation of the key invasion ligand, reticulocyte-binding homologue 4 (RH4), and the increased invasion was inhibited by antibodies to the RH4 receptor, CR1. Our data demonstrates a novel mechanism for inducing the switching of invasion pathways in P. falciparum parasites and may provide clues for understanding the mechanisms involved. © 2018 The Author(s).

Source: UG
Plasmodium falciparum uses a key functional site in complement receptor type-1 for invasion of human erythrocytes

The Plasmodium falciparum adhesin PfRh4 binds to complement receptor type-1 (CR1) on human erythrocytes and mediates a glycophorin-independent invasion pathway. CR1 is a complement regulator and immune-adherence receptor on erythrocytes required for shuttling of C3b/C4b-opsonized particles to liver and spleen for phagocytosis. Using recombinant CR1 constructs, we mapped the recognition site for PfRh4 to complement control protein modules 1 to 3 (CCP1-3) at the membrane-distal amino terminus of CR1. This region of CR1 binds to C4b and C3b and accelerates decay of both classic pathway and alternative pathway C3 and C5 convertases. CCP1-3 competed for PfRh4 binding to erythroid CR1 and inhibited the PfRh4-CR1 invasion pathways across a wide range of P falciparum strains. PfRh4 did not bind significantly to other CR1 constructs, including CCP15-17, which is 85% identical to CCP1-3. PfRh4 binding to CR1 did not affect its C3b/C4b binding capability, and we show evidence for a ternary complex between CCP1-3, C4b, and PfRh4. PfRh4 binding specifically inhibited CR1's convertase decay-accelerating activity, whereas there was no effect on factor H-mediated decay-accelerating activity. These results increase our understanding of the functional implications of CR1 engagement with PfRh4 and highlight the interplay between complement regulation and infection.

Source: UG
Plasmodium falciparum: Sensitivity to chloroquine in vivo in three ecological zones in Ghana

4690 children aged 6-15 years in 5 urban and 4 rural communities in 3 ecological zones in Ghana were screened from June 1988 to December 1990 to provide suitable candidates for the World Health Organization standard in vivo test for susceptibility of Plasmodium falciparum to chloroquine. 1880 (40.1%) had parasitaemia, mostly (83.7-98.6%) due to P. falciparum infection. Of the 626 in vivo tests performed, 570 (91.1%) showed sensitivity to chloroquine and 56 (8.9%) responses were classified as resistant to chloroquine at RI (5.1%) and RII (3.8%). The resistance responses were commonest (17.1-22.7%) in the coastal zone, followed by the savanna zone (8.6-10.0%), and lowest in the forest zone (3.1-6.3%). The RII responses occurred mainly in communities in the coastal zone. There was no RIII resistance in any zone. The pattern of RI (early) and RII responses of P. falciparum to chloroquine in this study suggested an increase in sensitivity, or a reduction in resistance, of P. falciparum to chloroquine from the coast to the forest and northern savanna zones, and from the urban to the rural communities in each zone in Ghana.

Source: UG
Plasmodium falciparum: sensitivity to chloroquine in wiwo in three ecological zones in Ghana

The Epidemiology Department contributes to the mission of the institute through basic and applied epidemiological research on, but not limited to, malaria and other diseases of public health importance. It is also home to the Social Science Unit of the Institute, including the Health Support Centre for HIV/AIDS and other communicable and noncommunicable health problems.

Source: UG
Plasmodium infection is associated with cross‑reactive antibodies to carbohydrate epitopes on the SARS‑CoV‑2 Spike protein

The Department of Parasitology conducts research into parasitic diseases of public health importance with the overall goal of reducing their transmission and the heavy disease burden that they impose on affected populations. The Department maintains focus on parasitic diseases in general. These include major diseases such as malaria, and others listed under the Neglected Tropical Diseases (NTD) control initiative such as, lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis, trypanosomiasis and leishmaniasis.

Source: UG
Plasmodium malariae and Plasmodium falciparum comparative susceptibility to antimalarial drugs in Mali

Objectives: To evaluate Plasmodium malariae susceptibility to current and lead candidate antimalarial drugs. Methods: We conducted cross-sectional screening and detection of all Plasmodium species malaria cases, which were nested within a longitudinal prospective study, and an ex vivo assessment of efficacy of a panel of antimalarials against P. malariae and Plasmodium falciparum, both PCR-confirmed mono-infections. Reference compounds tested included chloroquine, lumefantrine, artemether and piperaquine, while candidate antimalarials included the imidazolopiperazine GNF179, a close analogue of KAF156, and the Plasmodium phosphatidylinositol- 4-OH kinase (PI4K)-specific inhibitor KDU691. Results: We report a high frequency (3%–15%) of P. malariae infections with a significant reduction in ex vivo susceptibility to chloroquine, lumefantrine and artemether, which are the current frontline drugs against P. malariae infections. Unlike these compounds, potent inhibition of P. malariae and P. falciparum was observed with piperaquine exposure. Furthermore, we evaluated advanced lead antimalarial compounds. In this regard, we identified strong inhibition of P. malariae using GNF179, a close analogue of KAF156 imidazolopiperazines, which is a novel class of antimalarial drug currently in clinical Phase IIb testing. Finally, in addition to GNF179, we demonstrated that the Plasmodium PI4K-specific inhibitor KDU691 is highly inhibitory against P. malariae and P. falciparum. Conclusions: Our data indicated that chloroquine, lumefantrine and artemether may not be suitable for the treatment of P. malariae infections and the potential of piperaquine, as well as new antimalarials imidazolopiperazines and PI4K-specific inhibitor, for P. malariae cure.

Source: UG
Plasmodium malariae structure and genetic diversity in sub‑Saharan Africa determined from microsatellite variants and linked SNPs in orthologues of antimalarial resistance genes

The Epidemiology Department contributes to the mission of the institute through basic and applied epidemiological research on, but not limited to, malaria and other diseases of public health importance. It is also home to the Social Science Unit of the Institute, including the Health Support Centre for HIV/AIDS and other communicable and noncommunicable health problems.

Source: UG
Plasmodium malariae, current knowledge and future research opportunities on a neglected malaria parasite species

Plasmodium malariae is often reported as a benign malaria parasite. There are limited data on its biology and disease burden in sub-Saharan Africa (sSA) possibly due to the unavailability of specific and affordable tools for routine diagnosis and large epidemiology studies. In addition, P. malariae occurs at low parasite densities and in co-infections with other species, predominately P. falciparum. The paucity of data on P. malariae infections limits the capacity to accurately deter mine its contribution to malaria and the effect of control interventions against P. falciparum on its prevalence. Here, we summarise the current knowledge on P. malariae epidemiology in sSA - overall prevalence ranging from 0-32%, as detected by different diagnostic methods; seroprevalence ranging from 0–56% in three countries (Mozambique, Benin and Zimbabwe), and explore the future application of next-generation sequencing technologies as a tool for enriching P. malariae genomic epidemiology. This will provide insights into important adaptive mechanisms of this neglected non-falciparum species, including antimalarial drug resistance, local and regional parasite transmission patterns and genomic signatures of selection. Improved diagnosis and genomic surveillance of non-falciparum malaria parasites in Africa would be helpful in evaluating progress towards elimination of all human Plasmodium species.

Source: UG
Plasmodium yoelii17XL infection up-regulates RANTES, CCR1, CCR3 and CCR5 expression, and induces ultrastructural changes in the cerebellum

The Department of Parasitology conducts research into parasitic diseases of public health importance with the overall goal of reducing their transmission and the heavy disease burden that they impose on affected populations. The Department maintains focus on parasitic diseases in general. These include major diseases such as malaria, and others listed under the Neglected Tropical Diseases (NTD) control initiative such as, lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis, trypanosomiasis and leishmaniasis.

Source: UG
Plasmonic Nanocomposite Implants for Interstitial Thermotherapy: Experimental and Computational Analysis

The ferromagnetic implant (thermoseeds) technique offers desirable features for interstitial thermotherapy. However, its efficacy has been reported to be limited by issues that are related to the properties of the metal alloys that are used to fabricate them and the high number of thermoseeds needed to achieve therapeutic temperature levels. Here, we present the results of a combination of experimental and computational analysis of plasmonic nanocomposite implants (photoseeds)—a combination of Au nanoparticles (NPs) and poly-dimethylsiloxane (PDMS)—as a model material. We performed structural and optical characterization of the Au NPs and repared Au-PDMS nanocomposites, followed by an elucidation of the heat generation capabilities of the Au-PDMS photoseeds in aqueous solution and in-vitro cancer cell suspension. Based on the experimental results, we developed a three-dimensional (3D) finite element method (FEM) model to predict in-vivo thermal damage profiles in breast tissue. The optical absorbance of the Au-PDMS photoseeds were increasing with the concentration of Au NPs. The photothermal measurements and the in-vivo predictions showed that the photothermal properties of the photoseeds, characteristics of the laser sources, and the duration of heating can be tuned to achieve therapeutic temperature levels under in-vitro and in-vivo conditions. Collectively, the results demonstrate the feasibility of using photoseeds for interstitial thermotherapy.

Source: UG
The platform executive: Technology shaping of executive cognition during digital service innovation

The upsurge of digital innovations around the world has led to the establishment of many digital organizations, mostly small-medium, that focus on digital service innovation. For such organizations, the dominant use of digital technologies significantly shapes the cognition of their executives. But technology shaping of executive cognition is underresearched and, hence, underexplained. This paper seeks to address this limitation through an empirical study informed by critical realism and media ecology theory. The study explains how and why digital technology shapes executive cognition through combined influence of digital platforms and applications, service innovation, and executive functions. This explanation leads to the conceptualization of the executive of the digital organization as a platform. The Platform Executive is characterized by cognitive restructuring in a rapid and innovative manner during engagement with digital technologies. Based on these explanations, the paper discusses the theoretical, research, and practical implications.

Source: UG
Platinum-Group Mineral Occurrences and Platinum-Group Elemental Geochemistry of the Xiadong Alaskan-Type Complex in the Southern Central Asian Orogenic Belt

Alaskan-type complexes commonly contain primary platinum-group element (PGE) alloys and lack base-metal sulfides in their dunite and chromite-bearing rocks. They could therefore host PGE deposits with rare sulfide mineralization. A detailed scanning electron microscope investigation on dunites from the Xiadong Alaskan-type complex in the southern Central Asian Orogenic Belt revealed: various occurrences of platinum-group minerals (PGMs) that are dominated by inclusions in chromite grains containing abundant Ru, Os, S and a small amount of Pd and Te, indicating that they mainly formed prior to or simultaneously with the crystallization of the host minerals; A few Os–Ir–Rurich phases with iridium/platinum-group element (IPGE) alloy, anduoite (Ru,Ir,Ni)(As,S)2−x and irarsite (IrAsS) were observed in chromite fractures, and as laurite (RuS2) in clinopyroxene, which was likely related to late-stage hydrothermal alteration. The rocks in the Xiadong complex display large PGE variations with ∑PGE of 0.38–112 ppb. The dunite has the highest PGE concentrations (8.69–112 ppb), which is consistent with the presence of PGMs. Hornblende clinopyroxenite, hornblendite and hornblende gabbro were all depleted in PGEs, indicating that PGMs were likely already present at an early phase of magma and were mostly collected afterward in dunites during magma differentiation. Compared with the regional mafic–ultramafic intrusions in Eastern Tianshan, the Xiadong complex show overall higher average PGE concentration. This is consistent with the positive PGE anomalies revealed by regional geochemical surveys. The Xiadong complex, therefore, has potential for PGE exploration.

Source: UG
Play Pedagogy: Perspectives of Basic School Teachers in Ghana

This study examined the play beliefs of basic school teachers in Ghana. Participants were a purposive sample of 571 basic school teachers from three regions of Ghana. The Play Beliefs Inventory (PBI) served as the data source. The PBI included forty items designed to assess teachers' play beliefs within two subscales: Play Focus (PF) and Traditional African Play (TAP). Teachers responded to a five-point Likert scale ranging from strongly agree (scored 5) to strongly disagree (scored 1). A higher score indicated a stronger play belief and a lower score a weaker play belief. The PBI had a Cronbach's alpha of.833. Data across the entire sample indicated that most of the teachers reported strong play beliefs. Experienced teachers were more likely to report lower play beliefs. Play beliefs of males and females were similar. Two-Way Analyses of Variance indicated that region, professional qualification, and certification had significant effects for PF, TAP, and PBI-grade level was not significant. The number of girls in class was significant, while the overall class size was not. However, region showed significant interactions with grade level and certification, but not with professional qualification. Teachers with post-secondary certificates had lower play beliefs than untrained teachers, those with diplomas or bachelor's degrees. Teachers with early childhood certification had higher play beliefs than those with general basic education certification. These findings indicate that region, professional qualification, certification, and the number of girls in class were significant factors that should be considered in attempts to raise the status of play in the development and learning among young children. © Common Ground Research Networks, Lirije Olluri, Sejdi Sejdiu.

Source: UG
Playing the catch-up game: Accelerating the scale-up of prevention of mother-to-child transmission of HIV (PMTCT) services to eliminate new pediatric HIV infection in Nigeria

Introduction As the world is making progress towards elimination of mother-to-child transmission of HIV, poor coverage of PMTCT services in Nigeria remains a major challenge. In order to address this, scale-up was planned with activities organized into 3 phases. This paper describes the process undertaken in eight high burden Nigerian states to rapidly close PMTCT coverage gaps at facility and population levels between February 2013 and March 2014. Methods Activities were grouped into three phases-pre-assessment phase (engagement of a wide range of stakeholders), assessment (rapid health facility assessment, a cross sectional survey using mixed methods conducted in the various states between Feb and May 2013 and impact modelling), and post-assessment (drawing up costed state operational plans to achieve eMTCT by 2015, data-driven smart scale-up). Results Over a period of 10 months starting June 2013, 2044 facilities were supported to begin provision of PMTCT services. This increased facility coverage from 8% to 50%. A 246% increase was also recorded in the number of pregnant women and their families who have access to HIV testing and counselling in the context of PMTCT. Similarly, access to antiretrovirals for PMTCT has witnessed a 152% increase in these eight states between October 2013 and October 2014 Conclusion A data-driven and participatory approach can be used to rapidly scale-up PMTCT services at community and facility levels in this region. These results present us with hope for real progress in Nigeria. We are confident that the efforts described here will contribute significantly to eliminating new pediatric HIV infection in Nigeria.

Source: UG
Playing the Second Fiddle: Reflections on Running Mate Selection and the Vice Presidency in the Fourth Republic of Ghana”

The Vice Presidency is the second highest political office in any republic, but historically, it has never constitutionally and practically been accorded the powers and prestige that it deserves. The mode of appointment has made the running mate only an appendage to the presidential candidate. No one votes for the vice president per se; he is part of a package deal and not an independent choice. In office, the vice president remains ‘a second man position’ to the president who has all the powers and resources to perform his duties. More importantly, the vice president’s position is surrounded with paradoxes in the sense that often the president, reluctant to take the vice president into full confidence, takes his decisions with his immediate staff, leaving the vice president a sullen outsider. These apparent dilemmas surrounding the running mate selection process and around the position of the vice president in Ghana’s Fourth Republic are what this study seeks to explore

Source: UG
Please, thank you and sorry – brokering migration and constructing identities for domestic work in Ghana

Drawing on interviews with migrant domestic workers and brokers in Accra-Tema, the capital city of Ghana, this paper throws light on the everyday practices of brokers in producing ideal workers for urban middle class and expatriate families as well as overseas employment. The authors map the different kinds of brokers who are involved in the selection and placement of domestic workers and show how they filter and represent workers to potential employers. Women and girls from the poorer north and Volta regions are positioned into precarious employment with an ever-present risk of abuse, non-payment and sexual exploitation. In the absence of effective state protection these workers depend heavily on brokers for negotiating better working conditions and switching jobs if they are in a difficult position. By examining such dynamics the authors demonstrate how the process of brokerage itself offers these workers opportunities for exercising agency that have the potential of setting them on an upward path. The authors conclude with calls for a more nuanced and differentiated understanding of the role and the practices of brokers to better inform Ghana’s efforts to minimise exploitation of domestic workers.

Source: UG
Pleomorphic adenoma of salivary gland: To what extent does fine needle aspiration cytology reflect histopathological features?

Objective: The histological diversity encountered in pleomorphic adenoma may cause diagnostic difficulty in fine needle aspiration (FNA) cytology due to limited and selective sampling. The present study based on 25 histologically confirmed pleomorphic adenoma cases attempts to find out to what extent FNA cytology reflects the histopathological features. Methods: May-Grünwald- Giemsa and Papanicolaou stained smears, and haematoxylin and eosin stained paraffin sections of 25 pleomorphic adenomas of parotid and submandibular glands were reviewed. The cellularity, which was assessed in a sliding scale of 1+ to 4+, and proportions of epithelial to mesenchymal components in FNA smears and histology was determined and compared. The frequency of morphological features such as squamous metaplastic cells, cells with oncocytic change, acinus formation, mucus globules, papilla formation, giant cells, myxoid and chondroid matrix as well as specific nuclear features was compared between the two diagnostic methods, and the statistical significance was determined using Fisher's exact test of probability. Results: There was complete concordance between cytology and histology with respect to overall cellularity in 14 (56.0%) cases and in the proportions of epithelial to mesenchymal components in 13 (52.0%). Epithelial cells and myxoid matrix were present in all cases. There was no significant difference between smear and tissue section with respect to frequency of squamous metaplasia, oncocytic change, acinus formation, papilla formation, mucus globules, giant cells, nuclear pleomorphism, nuclear chromatin pattern, and mitotic figures. Morphological parameters that were significantly higher in FNAC compared with histology included intranuclear cytoplasmic inclusions (36.0% versus 8.0%, p = 0.0374), nuclear grooves (84.0% versus 48.0%, p = 0.0090), and reniform nuclei (20.0% versus 0.0%, p = 0.0502). Chondroid matrix was the only parameter which was significantly more common in histology than in cytology (44.0% versus 4.0%, p = 0.019). Conclusion: FNA cytology demonstrates well most of the histological features of pleomorphic adenoma of salivary gland and may be considered a useful tool in initial assessment of the tumour.

Source: UG
Plurilingualism and the learning of French as a foreign language in Ghana

ABSTRACT The current article studies the competencies of plurilingual students and how these competencies are exploited in the learning of French as a Foreign Language. Adopting a translanguaging theoretical approach, we argue that learners of foreign languages who already speak at least one other language have some linguistic competencies which manifest during their learning of the French language. Through observation of learners of French at the University of Ghana Business School and analysis of their written production, we confirm that some of these plurilingual competencies in students are demonstrated in the nature of the errors identified. The paper therefore recommends that learners’ existing competencies be taken into account and built upon when developing lessons for the foreign language classroom and during classroom delivery

Source: UG