46 research outputs found
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 (ÎŁ8) and carbon-normalized yields (Î8), equivalent to losses of ~45, 85â95, \u3e95 and \u3e95% of initial values, respectively, and a +3.1 % enrichment of the δ13C-DOC signature. The loss of Î8 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 Î8 (e.g., a355 versus Î8; 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
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 âstrength-of-evidenceâ 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 â Kaposiâs sarcoma, cervical cancer, non-Hodgkinâs and Hodgkinâs 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
Implementing SLMTA in the Kenya National Blood Transfusion Service: lessons learned
Background: The Kenya National Blood Transfusion Service (KNBTS) is mandated to provide safe and sufficient blood and blood components for the country. In 2013, the KNBTS National Testing Laboratory and the six regional blood transfusion centres were enrolled in the Strengthening Laboratory Management Toward Accreditation (SLMTA) programme. The process was supported by Global Communities with funding from the United States Centers for Disease Control and Prevention.
Methods: The SLMTA implementation at KNBTS followed the standard three-workshop series, on-site mentorships and audits. Baseline, midterm and exit audits were conducted at the seven facilities, using a standard checklist to measure progress. Given that SLMTA was designed for clinical and public health laboratories, key stakeholders, guided by Global Communities, tailored SLMTA materials to address blood transfusion services, and oriented trainers, auditors and mentors on the same.
Results: The seven facilities moved from an average of zero stars at baseline to an average of three stars at the exit audit. The average baseline audit score was 38% (97 points), midterm 71% (183 points) and exit audit 79% (205 points). The Occurrence Management and Process Improvement quality system essential had the largest improvement (at 67 percentage points), from baseline to exit, whereas Facilities and Safety had the smallest improvement (at 31 percentage points).
Conclusion: SLMTA can be an effective tool for preparing a blood transfusion service for accreditation. Key success factors included customising SLMTA to blood transfusion activities; sensitising trainers, mentors and auditors on operations of blood transfusion service; creating SLMTA champions in key departments; and integrating other blood transfusion-specific accreditation standards into SLMTA
Differentiated care preferences of stable patients on ART in Zambia: a discrete choice experiment
Background: Although differentiated service delivery (DSD) models for stable patients on antiretroviral therapy (ART) offer a range of health systems innovations, their comparative desirability to patients remains unknown. We conducted a discrete choice experiment to quantify service attributes most desired by patients to inform model prioritization
Methods: Between July and December 2016 a sample of HIV-positive adults on ART at 12 clinics in Zambia were asked to choose between two hypothetical facilities which differed across six DSD attributes. We used mixed logit models to explore preferences, heterogeneity and trade-offs
Results: Of 486 respondents, 59% were female and 85% resided in urban locations. Patients strongly preferred infrequent clinic visits (3 vs. 1-month visits: β (i.e. relative utility) =2.84; p <0.001). Milder preferences were observed for: waiting time for ART pick-up (1 vs. 6 hrs.; β=-0.67; p<0.001) or provider (1 vs. 3 hrs.; β=-0.41; p=0.002); âbuddyâ ART collection (β=0.84; p <0.001); and ART pick-up location (clinic vs. community: β=0.35; p=0.028). Urban patients demonstrated a preference for collecting ART at a clinic (β=1.32, p<0.001), and although the majority of rural patients preferred community ART pick-up (β=-0.74, p=0.049), 40% of rural patients still preferred facility ART collection.
Conclusions: Stable patients on ART primarily want to attend clinic infrequently, supporting a focus in Zambia on optimizing multi-month prescribing over other DSD features - particularly in urban areas. Substantial preference heterogeneity highlights the need for DSD models to be flexible, and accommodate both setting features and patient choice in their design
African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics
African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla. The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond. This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages
African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics
African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla. The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond. This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages
African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics
African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla. The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond. This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages
African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics
African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla. The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond. This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages
African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics
African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla. The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond. This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages
African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics
African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla. The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond. This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages