Laboratory evaluation of the flotation response of a copper cobalt oxide ore to gasoil-rinkalore mixtures

Froth flotation remains to date as one of the most used metallurgical processes for concentrating metal-bearing minerals in ores. Oxide ores are relatively less amenable to froth flotation and require a judicious choice of reagents for the recovery of metals to be optimised. Laboratory batch flotation tests were conducted to determine the effect of two types of gasoil-rinkalore mixtures on the flotation response of a copper cobalt oxide ore sample. The head assay conducted on the initial ore sample showed that it contained about 2.90% of Cu, 0.12% of Co. Upon the flotation test work, the results obtained indicated that the concentrate obtained with use of the mixture gasoil-rinkalore RX yielded 8.24% Cu and 0.22% Co concentrate grades with recoveries of 76.0% Cu and 78.0% Co respectively. But, the concentrate obtained by use of the mixture gazoil-rinkalore RX3 yielded relatively bad results with 5.92% Cu and 0.18% Cu concentrate grades with recoveries of 70.3% Cu and 65.3% Co respectively

Recherche du réservoir animal sauvage de Trypanosoma sp chez les mammifères de N'Djili-Brasseries à Kinshasa en République Démocratique du Congo (RDC)

Durant 6 mois, 201 spécimens de mammifères sauvages représentant 7 espèces réparties en 6 genres, 4 familles et 3 ordres, dont 2 Genetta angolensis, 3 Nandinia binotata, 10 Galagoides demidoff, 35 Protoxerus strangeri, 73 Funisciurus congicus, 15 Rattus rattus et 63 Rattus norvegicus, ont été capturés dans le quartier N’Djili-Brasseries en vue d’identifier le réservoir animal sauvage des trypanosomes. La présente étude a montré par la méthode de la réaction de polymérisation en chaîne, ou Polymerase Chain Reaction (PCR), que de ces sept espèces, seule  Rattus rattus et Rattus norvegicus capturées dans le secteur habité par l’homme avaient Trypanosoma brucei gambiense avec une prévalence de 13,3 % pour  Rattus rattus et 9,5 % pour  Rattus norvegicus, ce qui nous conduit à conclure que ces deux espèces seraient réservoirs de Trypanosoma brucei gambiense. Mots clés: Réservoir, Trypanosoma sp, mammifères, N’Djili-Brasseries, Kinshasa.During 6 months, 201 specimens of wild mammals representing 7 species divided into 6 genera, 4 families and 3 orders, of which 2 Genetta angolensis, 3 Nandinia binotata, 10 Galagoides demidoff, 35 Protoxerus strangeri, 73 Funisciurus congicus, 15 Rattus rattus and 63 Rattus norvegicus, were captured at N’Djili- Brasserie to identify the wild animal reservoir of trypanosoma. This study revealed by using the method of polymerase chain reaction (PCR) that among these seven species, only Rattus rattus and Rattus norvegicus, captured in the area inhabited by man, had Trypanosoma brucei gambiense with a prevalence of 13.3 % for Rattus rattus and 9.5 % for Rattus norvegicus. This lead us to conclude that these two species would be reservoir of Trypanosoma brucei gambiense. Keywords: Reservoir, Trypanosoma sp, mammals, N’Djili-Brasseries, Kinshasa

Lay perceptions, beliefs and practices linked to the persistence of anthrax outbreaks in cattle in the Western Province of Zambia

Anthrax, a neglected zoonotic disease that is transmitted by a spore-forming, rod-shaped bacterium, Bacillus anthracis, has reached endemic proportions in the Western Province of Zambia. Transmission of anthrax from the environment as well as between cattle has been observed to be partly because of entrenched beliefs, perceptions and traditional practices among cattle farmers in the known outbreak areas. This study was aimed at exploring lay perceptions, beliefs and practices that influence anthrax transmission in cattle of the Western Province. A mixed-methods study was conducted from August to December 2015. Quantitative data were collected using a cross-sectional survey. Qualitative data were generated by interviewing professional staff and community members. Five focus group discussions and five key informant interviews were conducted. Thematic analysis of interview data was performed using NVivo software. The findings suggested that cattle anthrax was biologically as well as culturally maintained. Cattle farmers were reluctant to have their livestock vaccinated against anthrax because of perceived low efficacy of the vaccine. Also, the cattle farmers did not trust professional staff and their technical interventions. Popular cultural practices that involved exchange of animals between herds contributed to uncontrolled cattle movements between herds and subsequent transmission of anthrax. These findings imply the need for professional staff to be culturally competent in handling socio-cultural issues that are known to be barriers for disease control in animals. There is a need to develop a policy framework that will foster integrated control of anthrax across disciplines

Photochemical Degradation of Dissolved Organic Matter and Dissolved Lignin Phenols from the Congo River

Photochemical degradation of Congo River dissolved organic matter (DOM) was investigated to examine the fate of terrigenous DOM derived from tropical ecosystems. Tropical riverine DOM receives greater exposure to solar radiation, particularly in large river plumes discharging directly into the open ocean. Initial Congo River DOM exhibited dissolved organic carbon (DOC) concentration and compositional characteristics typical of organic rich blackwater systems. During a 57 day irradiation experiment, Congo River DOM was shown to be highly photoreactive with a decrease in DOC, chromophoric DOM (CDOM), lignin phenol concentrations (Σ8) and carbon-normalized yields (Λ8), equivalent to losses of ~45, 85–95, \u3e95 and \u3e95% of initial values, respectively, and a +3.1 % enrichment of the δ13C-DOC signature. The loss of Λ8 and enrichment of δ13C-DOC during irradiation was strongly correlated (r = 0.99, p \u3c 0.01) indicating tight coupling between these biomarkers. Furthermore, the loss of CDOM absorbance was correlated to the loss of Λ8 (e.g., a355 versus Λ8; r = 0.98, p \u3c 0.01) and δ13C-DOC (e.g., a355 versus δ13C; r = 0.97, p \u3c 0.01), highlighting the potential of CDOM absorbance measurements for delineating the photochemical degradation of lignin and thus terrigenous DOM. It is apparent that these commonly used measurements for examination of terrigenous DOM in the oceans have a higher rate of photochemical decay than the bulk DOC pool. Further process-based studies are required to determine the selective removal rates of these biomarkers for advancement of our understanding of the fate of this material in the ocean

A counseling intervention to address HIV stigma at entry into antenatal care in Tanzania (Maisha): study protocol for a pilot randomized controlled trial.

BACKGROUND: HIV-related stigma significantly impacts HIV care engagement, including in prevention of mother-to-child transmission of HIV (PMTCT) programs. Maisha is a stigma-based counseling intervention delivered during the first antenatal care (ANC) visit, complementing routine HIV counseling and testing. The goal of Maisha is to promote readiness to initiate and sustain treatment among those who are HIV-positive, and to reduce HIV stigmatizing attitudes among those who test negative. METHODS: A pilot randomized control trial will assess the feasibility and acceptability of delivering Maisha in a clinical setting, and the potential efficacy of the intervention on HIV care engagement outcomes (for HIV-positive participants) and HIV stigma constructs (for all participants). A total of 1000 women and approximately 700 male partners will be recruited from two study clinics in the Moshi municipality of Tanzania. Participants will be enrolled at their first ANC visit, prior to HIV testing. It is estimated that 50 women (5%) will be identified as HIV-positive. Following consent and a baseline survey, participants will be randomly assigned to either the control (standard of care) or the Maisha intervention. The Maisha intervention includes a video and counseling session prior to HIV testing, and two additional counseling sessions if the participant tests positive for HIV or has an established HIV diagnosis. A subset of approximately 500 enrolled participants (all HIV-positive participants, and a random selection of HIV-negative participants who have elevated stigma attitude scores) will complete a follow-up assessment at 3 months. Measures will include health outcomes (care engagement, antiretroviral adherence, depression) and HIV stigma outcomes. Quality assurance data will be collected and the feasibility and acceptability of the intervention will be described. Statistical analysis will examine potential differences between conditions in health outcomes and stigma measures, stratified by HIV status. DISCUSSION: ANC provides a unique and important entry point to address HIV stigma. Interventions are needed to improve retention in PMTCT care and to improve community attitudes toward people living with HIV. Results of the Maisha pilot trial will be used to generate parameter estimates and potential ranges of values to estimate power for a full cluster-randomized trial in PMTCT settings, with extended follow-up and enhanced adherence measurement using a biomarker.

Developing Clinical Strength-of-Evidence Approach to Define HIV-Associated Malignancies for Cancer Registration in Kenya

Background Sub-Saharan Africa cancer registries are beset by an increasing cancer burden further exacerbated by the AIDS epidemic where there are limited capabilities for cancer-AIDS match co-registration. We undertook a pilot study based on a “strength-of-evidence” approach using clinical data that is abstracted at the time of cancer registration for purposes of linking cancer diagnosis to AIDS diagnosis. Methods/Findings The standard Nairobi Cancer Registry form was modified for registrars to abstract the following clinical data from medical records regarding HIV infection/AIDS in a hierarchal approach at time of cancer registration from highest-to-lowest strength-of-evidence: 1) documentation of positive HIV serology; 2) antiretroviral drug prescription; 3) CD4+ lymphocyte count; and 4) WHO HIV clinical stage or immune suppression syndrome (ISS), which is Kenyan terminology for AIDS. Between August 1 and October 31, 2011 a total of 1,200 cancer cases were registered. Of these, 171 cases (14.3%) met clinical strength-of-evidence criteria for association with HIV infection/AIDS; 69% (118 cases were tumor types with known HIV association – Kaposi’s sarcoma, cervical cancer, non-Hodgkin’s and Hodgkin’s lymphoma, and conjunctiva carcinoma) and 31% (53) were consistent with non-AIDS defining cancers. Verifiable positive HIV serology was identified in 47 (27%) cases for an absolute seroprevalence rate of 4% among the cancer registered cases with an upper boundary of 14% among those meeting at least one of strength-of-evidence criteria. Conclusions/Significance This pilot demonstration of a hierarchal, clinical strength-of-evidence approach for cancer-AIDS registration in Kenya establishes feasibility, is readily adaptable, pragmatic, and does not require additional resources for critically under staffed cancer registries. Cancer is an emerging public health challenge, and African nations need to develop well designed population-based studies in order to better define the impact and spectrum of malignant disease in the backdrop of HIV infection

Assessing the impact of aggregating disease stage data in model predictions of human African trypanosomiasis transmission and control activities in Bandundu province (DRC)

Since the turn of the century, the global community has made great progress towards the elimination of gambiense human African trypanosomiasis (HAT). Elimination programs, primarily relying on screening and treatment campaigns, have also created a rich database of HAT epidemiology. Mathematical models calibrated with these data can help to fill remaining gaps in our understanding of HAT transmission dynamics, including key operational research questions such as whether integrating vector control with current intervention strategies is needed to achieve HAT elimination. Here we explore, via an ensemble of models and simulation studies, how including or not disease stage data, or using more updated data sets affect model predictions of future control strategies

A Narrative Synthesis of Literature on the Barriers to Timely Diagnosis and Treatment of Cancer in Sub-Saharan Africa.

Poor cancer survival outcomes in sub-Saharan Africa (SSA) have been linked to delays in diagnosis and treatment. Here we present a detailed overview of the qualitative literature evaluating the barriers to receiving timely diagnosis and treatment of cancer in SSA. The PubMed, EMBASE, CINAHL, PsycINFO databases were searched to identify qualitative studies reporting on barriers to timely diagnosis of cancer in SSA published between 1995 and 2020. A systematic review methodology was applied, including quality assessment and narrative data synthesis. We identified 39 studies, of which 24 focused on breast or cervical cancer. Only one study focused on prostate cancer and one on lung cancer. When exploring factors contributing to delays, six key themes emerged from the data. The first theme was health service barriers, which included: (i) inadequate numbers of trained specialists; (ii) limited knowledge of cancer among healthcare providers; (iii) poor co-ordination of care; (iv) inadequately resourced health facilities; (v) negative attitudes of healthcare providers towards patients; (vi) high cost of diagnostic and treatment services. The second key theme was patient preference for complementary and alternative medicine; the third was the limited understanding of cancer among the population. The fourth barrier was a patient's personal and family obligations; the fifth was the perceived impact of cancer and its treatment on sexuality, body image and relationships. Finally, the sixth was the stigma and discrimination faced by patients following a diagnosis of cancer. In conclusion, health system, patient level and societal factors all influence the likelihood of timely diagnosis and treatment for cancer in SSA. The results provide a focus for targeting health system interventions, particular with regards to awareness and understanding of cancer in the region