Enabling condition based maintenance in a precious metal processing plant

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Investigating the effect of acid stress on selected mesophilic micro-organisms implicated in bioleaching

During start-up of heap bioleaching, low grade ores are typically treated with acid for agglomeration and to combat the acid neutralising capacity of the gangue minerals. This may stress the bioleaching inocula, particularly upon inoculation during ore agglomeration. Acid addition for agglomeration varies across operations, ore types and their neutralising capacity, with limited information published on recommended concentrations. The initial pH in the agglomeration mix is typically below pH 1.0 and may be as low as pH 0.5. This paper investigates the effect of acid stress in terms of initial acid concentration and exposure duration in submerged culture on mesophilic bacteria typically implicated in mineral sulphide bioleaching and critical for heap colonisation at start-up. Following acid stress, cultures were returned to standard operating conditions in batch stirred slurry reactors and their performance assessed in terms of mineral leach rates, ferrous oxidation and the rate of microbial growth. Increasing acid stress resulted in an increase in the lag period before onset of microbial growth and iron oxidation. Following adaptation, typical growth and ferrous iron oxidation rates were observed under low stress conditions while reduction in the rate and extent of microbial growth and ferrous iron oxidation persisted at extreme conditions. A reduction in yield (microbial cells produced per kg iron oxidised) was observed with increased acid concentration over comparative times. Microbial speciation analysis indicated a substantial decrease in the diversity of surviving bacterial species

The Role of Abdominal Ultrasound and |Chest Radiography in Management of Breast Cancer Patients in a Low Resource Country: A Case of Tanzania

Background: Breast cancer is among the commonest cancers affecting women in Tanzania. Most of them seek hospital treatment when the disease has reached an advanced stage. Hence widely available modalities like ultrasound (LUS) and chest radiograph (CXR) can be used to establishmetastasis in newly diagnosed patients. The main objective of this study was to determine the role of abdominal ultrasound and chest radiography in detection of liver and lung metastasis in newly diagnosed breast cancer patients.Methods: This was a descriptive cross sectional study in which 103 new breast cancer patients attending Ocean Road Cancer Institute (ORCI) were recruited consecutively. All participants were investigated for liver and lung metastases using abdominal ultrasound and chest x-ray respectively.Standardized questionnaires were used to obtain socio-demographic and to document examination findings.Results: Participants were aged between 26 – 77 years, with a mean of 48±11.22. The prevalence of metastasis to the liver and lungs were 18.4% and 20.4% respectively. Majority of patients with breast cancer had locally advanced breast cancer disease that is either TNM stage three (59.2%) or four (32%) disease upon arrival to ORCI.Conclusion: This study has demonstrated a high detection rate of LUS and CXR for liver and lung metastasis in patients with locally advanced breast cancer

Lessons from a year of COVID-19 in Zambia: reported attendance and mask wearing at large gatherings in rural communities

Zambia instituted prevention behavior guidelines for social gatherings before the first case of COVID-19 was confirmed on March 18, 2020. Guidelines included nonpharmaceutical interventions (NPIs) including mask wearing, social distancing, and reducing sizes of gatherings. Within a larger cluster randomized trial of community-based parenting groups in four rural districts (three in Southern Province, one in Eastern Province), we collected 5,711 questionnaires from intervention participants between August 2020 and September 2021, during which the country saw two COVID-19 waves. Questionnaires asked about participation and behaviors at community gatherings. Generally, perception of risk of contracting COVID-19 was low for respondents in districts in Southern Province but higher for those in Eastern Province. The highest compliance to mask wearing was reported at clinics (84%) and church services (81%), which were the most frequently attended gatherings. Many funerals were attended by 200 to 300 people, but individuals were 30% less likely to report wearing masks (odds ratio [OR] = 0.71, 95% confidence ratio [CI]: 0.6-0.8) than those attending a clinic visit. After controlling for other variables, the odds of self-reported mask wearing at events were higher in January to March 2021 (adjusted OR = 1.5, 95% CI: 1.3, 1.7) and July and September of 2021 (adjusted OR = 3.0, 95% CI: 2.5-3.5), timepoints that broadly overlay with two COVID-19 peaks observed in Zambia. Results suggest guideline dissemination penetrated the rural areas. However, there is need to optimize the messaging to increase compliance to NPIs at high-risk gatherings, including funerals. The findings from this analysis should be considered as the COVID-19 pandemic continues to evolve

Determinants of Acceptance of Cervical Cancer Screening in Dar es Salaam, Tanzania.

To describe how demographic characteristics and knowledge of cervical cancer influence screening acceptance among women living in Dar es Salaam, Tanzania. Multistage cluster sampling was carried out in 45 randomly selected streets in Dar es Salaam. Women between the ages of 25-59 who lived in the sampled streets were invited to a cervical cancer screening; 804 women accepted and 313 rejected the invitation. Information on demographic characteristics and knowledge of cervical cancer were obtained through structured questionnaire interviews. Women aged 35-44 and women aged 45-59 had increased ORs of 3.52 and 7.09, respectively, for accepting screening. Increased accepting rates were also found among single women (OR 2.43) and among women who had attended primary or secondary school (ORs of 1.81 and 1.94). Women who had 0-2 children were also more prone to accept screening in comparison with women who had five or more children (OR 3.21). Finally, knowledge of cervical cancer and awareness of the existing screening program were also associated with increased acceptance rates (ORs of 5.90 and 4.20). There are identifiable subgroups where cervical cancer screening can be increased in Dar es Salaam. Special attention should be paid to women of low education and women of high parity. In addition, knowledge and awareness raising campaigns that goes hand in hand with culturally acceptable screening services will likely lead to an increased uptake of cervical cancer screening

Trends in maternal mental health during the COVID-19 pandemic-evidence from Zambia

The COVID-19 pandemic has increased social and emotional stressors globally, increasing mental health concerns and the risk of psychiatric illness worldwide. To date, relatively little is known about the impact of the pandemic on vulnerable groups such as women and children in low-resourced settings who generally have limited access to mental health care. We explore two rounds of data collected as part of an ongoing trial of early childhood development to assess mental health distress among mothers of children under 5-years-old living in two rural areas of Zambia during the COVID-19 pandemic. We examined the prevalence of mental health distress among a cohort of 1105 mothers using the World Health Organization's Self-Reporting Questionnaire (SRQ-20) before the onset of the COVID-19 pandemic in August 2019 and after the first two infection waves in October-November 2021. Our primary outcome was mental health distress, defined as SRQ-20 score above 7. We analyzed social, economic and family level characteristics as factors modifying to the COVID-19 induced changes in the mental health status. At baseline, 22.5% of women were in mental health distress. The odds of mental health distress among women increased marginally over the first two waves of the pandemic (aOR1.22, CI 0.99-1.49). Women under age 30, with lower educational background, with less than three children, and those living in Eastern Province (compared to Southern Province) of Zambia, were found to be at highest risk of mental health deterioration during the pandemic. Our findings suggest that the prevalence of mental health distress is high in this population and has further worsened during COVID-19 pandemic. Public health interventions targeting mothers' mental health in low resource settings may want to particularly focus on young mothers with limited educational attainment

A qualitative assessment of community acceptability and use of a locally developed children's book to increase shared reading and parent-child interactions in rural Zambia

INTRODUCTION: Early reading interventions hold promise for increasing language and literacy development in young children and improving caregiver-child interactions. To engage rural caregivers and young children in home reading, Zambian child psychologists and education specialists developed a culturally representative, local language children's book targeted at pre-grade 1 children. OBJECTIVES: We qualitatively assessed community acceptability and use of the book distributed to households with young children in two provinces of Zambia. METHODS: We conducted 15 focus group discussions (FGDs) with women (n=117) who received the "Zambian folktales adapted stories for young children" book. A codebook was created a priori, based on established themes in the guide; content analysis was conducted in Nvivo v12. Data were interpreted against the Theoretical Framework on Acceptability. FINDINGS: Respondents described wide acceptability of the children's book across multiple framework constructs. Respondents believed the book was culturally appropriate for its folktale structure and appreciated the morals and lessons provided by the stories. Respondents described using the book in multiple ways including reading in one-on-one or group settings, asking the child questions about the narrative or pictures, and providing additional commentary on the actions or figures in the pictures. Respondents believed the books were helping children grow their vocabulary and early literacy skills. The book's simple vocabulary facilitated use by less educated caregivers. The primary concern voiced was the ability of low literacy caregivers to utilize the book for reading. DISCUSSION: The children's book was widely considered acceptable by rural Zambian communities. It provided a platform for an additional method of caregiver-child interactions in these households for reading, dialogue, and oral storytelling. Shared reading experiences have potentially substantial benefits for the language development and emergent literacy of young children. Programs to develop and deliver culturally acceptable books to households with limited access should be considered by governments and funders

COVID-19 knowledge and prevention behaviors in rural Zambia: a qualitative application of the information-motivation-behavioral skills model

In early 2020, the Zambian Ministry of Health instituted prevention guidelines to limit spread of COVID-19. We assessed community knowledge, motivations, behavioral skills, and perceived community adherence to prevention behaviors (i.e., hand hygiene, mask wearing, social distancing, and limiting gatherings). Within a cluster-randomized controlled trial in four rural districts, in November 2020 and May 2021, we conducted in-depth interviews with health center staff (N = 19) and community-based volunteers (N = 34) and focus group discussions with community members (N = 281). A content analysis was conducted in Nvivo v12. Data were interpreted using the Information-Motivation-Behavioral Skills Model. Generally, respondents showed good knowledge of COVID-19 symptoms, spread, and high-risk activities, with some gaps. Prevention behavior performance was driven by personal and social factors. Respondents described institutional settings (e.g., clinics and church) having higher levels of perceived adherence due to stronger enforcement measures and clear leadership. Conversely, informal community settings (e.g., weddings, funerals, football matches) lacked similar social and leadership expectations for adherence and had lower perceived levels of adherence. These settings often involved higher emotions (excitement or grief), and many involved alcohol use, resulting in community members "forgetting" guidelines. Doubt about disease existence or need for precautions persisted among some community members and drove non-adherence more generally. Although COVID-19 information successfully penetrated these very remote rural communities, more targeted messaging may address persistent COVID-19 doubt and misinformation. Engaging local leaders in religious, civic, and traditional leadership positions could improve community behaviors without adding additional monitoring duties on an already overburdened, resource-limited health system