126 research outputs found

    Quantitative and mechanistic analysis of impact of novel cassava-assisted improved processing on fluid transport phenomenon in humidity-temperature-stressed bio-derived films

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    Bio-derived films’ realistic performance integrity is ascertained by their resilience in highly-stressful storage conditions, a function of its ability to respond timely and manages fluid barrier appropriately. Bio-derived films’ moisture and temperature sensitivity often posed mass transport challenges, thus decreasing their lifespan. Quantifying bio-derived film mass transport behaviour has been limited to mass transfer representations, which can be imperfect to understand fully mass transport phenomenon. This study reported quantitative and mechanistic analysis of fluid-phase mass transport phenomenon in Simultaneous Release Recovery Cyanogenesis-produced intact bitter cassava (IBC) bio-derived films under stressful conditions. Films were tested for solvent solubility, swelling ratio, sorption and permeability to water vapour and oxygen at 10–40 °C and 10–95% RH. Film’s structural alterations were characterised by their thermal and chemical properties. Modified-BET, Peleg, Oswin models best described sorption data. Temperature-dependence of film water vapour permeability was simulated best by Arrhenius model, while oxygen permeability was influenced highly by crystallinity and RH. Non-organic and organic film-solvent diffusion followed case II and Fickian diffusional patterns respectively. Solvents induced structural changes in IBC films with concentration-dependent diffusion. Cassava bio-derived films’ integrity will depend on the host environment, thus maximum care should be ensured to minimise environment impact during applications. Nonetheless, IBC films hold potential as biomaterials for broad range product use

    Novel Intact Bitter Cassava: Sustainable Development and Desirability Optimisation of Packaging Films

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    This is a research article on novel biomaterials and optimal processing conditions are fundamental in low-cost packaging material production.Novel biomaterials and optimal processing conditions are fundamental in low-cost packaging material production. Recently, a novel biobased intact bitter cassava derivative was developed using an intrinsic, high-throughput downstream processing methodology (simultaneous release recovery cyanogenesis). Processing of intact bitter cassava can minimise waste and produce low-cost added value biopolymer packaging films. The objective of this study was to (i) develop and characterise intact bitter cassava biobased films and (ii) determine the optimal processing conditions, which define the most desirable film properties. Films were developed following a Box-Behnken design considering cassava (2, 3, 4 % w/v), glycerol (20, 30, 40 % w/w) and drying temperature (30, 40, 50 °C) and optimized using multi-response desirability. Processing conditions produced films with highly significant (p < 0.05) differences. Developed models predicted impact of processing conditions on film properties. Desirable film properties for food packaging were produced using the optimised processing conditions, 2 % w/v cassava, 40.0%w/w glycerol and 50 °C drying temperature. These processing conditions produced films with 0.3 %; transparency, 3.4 %; solubility, 21.8 %; water-vapour-permeability, 4.2 gmm/m2/day/kPa; glass transition, 56 °C; melting temperature, 212.6 °C; tensile strength, 16.3 MPa; elongation, 133.3 %; elastic modulus, 5.1MPa and puncture resistance, 57.9 J, which are adequate for packaging applications. Therefore, intact bitter cassava is a viable material to produce packaging films that can be tailored for specific sustainable, low-cost applications

    Carriage prevalence and serotype distribution of Streptococcus pneumoniae prior to 10-valent pneumococcal vaccine introduction: A population-based cross-sectional study in South Western Uganda, 2014.

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    BACKGROUND: Information on Streptococcus pneumoniae nasopharyngeal (NP) carriage before the pneumococcal conjugate vaccine (PCV) introduction is essential to monitor impact. The 10-valent PCV (PCV10) was officially introduced throughout Ugandan national childhood immunization programs in 2013 and rolled-out countrywide during 2014. We aimed to measure the age-specific Streptococcus pneumoniae carriage and serotype distribution across all population age groups in the pre-PCV10 era in South Western Uganda. METHODS: We conducted a two-stage cluster, age-stratified, cross-sectional community-based study in Sheema North sub-district between January and March 2014. One NP swab was collected and analyzed for each participant in accordance with World Health Organization guidelines. RESULTS: NP carriage of any pneumococcal serotype was higher among children <2years old (77%; n=387) than among participants aged ?15years (8.5%; n=325) (chi2 p<0.001). Of the 623 positive cultures, we identified 49 serotypes among 610 (97.9%) isolates; thirteen (2.1%) isolates were non-typeable. Among <2years old, serotypes 6A, 6B, 14, 15B, 19F and 23F accounted for half of all carriers. Carriage prevalence with PCV10 serotypes was 29.4% among individuals aged <2years (n=387), 23.4% in children aged 2-4years (n=217), 11.4% in 5-14years (n=417), and 0.4% among individuals ?15years of age (n=325). The proportion of carried pneumococci serotypes contained in PCV10 was 38.1% (n=291), 32.8% (n=154), 29.4% (n=156), and 4.4% (n=22) among carriers aged <2years, 2-4years, 5-14years and ?15years, respectively. DISCUSSION: In Sheema district, the proportion of PCV10 serotypes was low (<40%), across all age groups, especially among individuals aged 15years or older (<5%). PCV10 introduction is likely to impact transmission among children and to older individuals, but less likely to substantially modify pneumococcal NP ecology among individuals aged 15years or older

    Characteristics of human encounters and social mixing patterns relevant to infectious diseases spread by close contact: a survey in Southwest Uganda.

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    BACKGROUND: Quantification of human interactions relevant to infectious disease transmission through social contact is central to predict disease dynamics, yet data from low-resource settings remain scarce. METHODS: We undertook a social contact survey in rural Uganda, whereby participants were asked to recall details about the frequency, type, and socio-demographic characteristics of any conversational encounter that lasted for ≥5 min (henceforth defined as 'contacts') during the previous day. An estimate of the number of 'casual contacts' (i.e. < 5 min) was also obtained. RESULTS: In total, 566 individuals were included in the study. On average participants reported having routine contact with 7.2 individuals (range 1-25). Children aged 5-14 years had the highest frequency of contacts and the elderly (≥65 years) the fewest (P < 0.001). A strong age-assortative pattern was seen, particularly outside the household and increasingly so for contacts occurring further away from home. Adults aged 25-64 years tended to travel more often and further than others, and males travelled more frequently than females. CONCLUSION: Our study provides detailed information on contact patterns and their spatial characteristics in an African setting. It therefore fills an important knowledge gap that will help more accurately predict transmission dynamics and the impact of control strategies in such areas

    Taking up the cudgels against gay rights? Trends and trajectories in African Christian theologies on homosexuality

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    Against the background of the HIV epidemic and the intense public controversy on homosexuality in African societies, this article investigates the discourses of academic African Christian theologians on homosexuality. Distinguishing some major strands in African theology, that is, inculturation, liberation, women’s and reconstruction theology, the article examines how the central concepts of culture, liberation, justice, and human rights function in these discourses. On the basis of a qualitative analysis of a large number of publications, the article shows that stances of African theologians are varying from silence and rejection to acceptance. Although many African theologians have taken up the cudgels against gay rights, some “dissident voices” break the taboo and develop more inclusive concepts of African identity and African Christianity

    Predictors of linkage to care following community-based HIV counseling and testing in rural Kenya

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    Despite innovations in HIV counseling and testing (HCT), important gaps remain in understanding linkage to care. We followed a cohort diagnosed with HIV through a community-based HCT campaign that trained persons living with HIV/AIDS (PLHA) as navigators. Individual, interpersonal, and institutional predictors of linkage were assessed using survival analysis of self-reported time to enrollment. Of 483 persons consenting to follow-up, 305 (63.2%) enrolled in HIV care within 3 months. Proportions linking to care were similar across sexes, barring a sub-sample of men aged 18–25 years who were highly unlikely to enroll. Men were more likely to enroll if they had disclosed to their spouse, and women if they had disclosed to family. Women who anticipated violence or relationship breakup were less likely to link to care. Enrolment rates were significantly higher among participants receiving a PLHA visit, suggesting that a navigator approach may improve linkage from community-based HCT campaigns.Vestergaard Frandse

    Quality of Care in Contraceptive Services Provided to Young People in Two Ugandan Districts: A Simulated Client Study

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    BACKGROUND: Low and inconsistent use of contraceptives by young people contributes to unintended pregnancies. This study assessed quality of contraceptive services for young people aged 15-24 in two rural districts in Uganda. METHODS: Five female and two male simulated clients (SCs) interacted with 128 providers at public, private not-for-profit (PNFP), and private for profit (PFP) health facilities. After consultations, SCs were interviewed using a structured questionnaire. Six aspects of quality of care (client's needs, choice of contraceptive methods, information given to users, client-provider interpersonal relations, constellation of services, and continuity mechanisms) were assessed. Descriptive statistics and factor analysis were performed. RESULTS: Means and categorized quality scores for all aspects of quality were low in both public and private facilities. The lowest quality scores were observed in PFP, and medium scores in PNFP facilities. The choice of contraceptive methods and interpersonal relations quality scores were slightly higher in public facilities. Needs assessment scores were highest in PNFP facilities. All facilities were classified as having low scores for appropriate constellation of services. Information given to users was suboptimal and providers promoted specific contraceptive methods. Minority of providers offered preferred method of choice and showed respect for privacy. CONCLUSIONS: The quality of contraceptive services provided to young people was low. Concurrent quality improvements and strengthening of health systems are needed

    Constraints and prospects for contraceptive service provision to young people in Uganda: providers' perspectives

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    <p>Abstract</p> <p>Background</p> <p>Unintended pregnancies lead to unsafe abortions, which are a leading cause of preventable maternal mortality among young women in Uganda. There is a discrepancy between the desire to prevent pregnancy and actual contraceptive use. Health care providers' perspectives on factors influencing contraceptive use and service provision to young people aged 15-24 in two rural districts in Uganda were explored.</p> <p>Methods</p> <p>Semi-structured questionnaires were used for face- to-face interviews with 102 providers of contraceptive service at public, private not-for-profit, and private for-profit health facilities in two rural districts in Uganda. Descriptive and inferential statistics were used in the analysis of data.</p> <p>Results</p> <p>Providers identified service delivery, provider-focused, structural, and client-specific factors that influence contraceptive use among young people. Contraceptive use and provision to young people were constrained by sporadic contraceptive stocks, poor service organization, and the limited number of trained personnel, high costs, and unfriendly service. Most providers were not competent enough to provide long-acting methods. There were significant differences in providers' self-rated competence by facility type; private for-profit providers' competence was limited for most contraceptives. Providers had misconceptions about contraceptives, they had negative attitudes towards the provision of contraceptives to young people, and they imposed non-evidence-based age restrictions and consent requirements. Thus, most providers were not prepared or were hesitant to give young people contraceptives. Short-acting methods were, however, considered acceptable for young married women and those with children.</p> <p>Conclusion</p> <p>Provider, client, and health system factors restricted contraceptive provision and use for young people. Their contraceptive use prospects are dependent on provider behavior and health system improvements.</p
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