1,721,013 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Exploring spatial variations and factors associated with childhood stunting in Ethiopia: spatial and multilevel analysis
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Modeling the Potential Impact of Fortification Programs on Dietary Micronutrient Intakes among Young Children and Women of Reproductive Age in Low- and Middle-income Countries: Case Studies from Cameroon and Zambia
No full textABSTRACTIn low- and middle-income countries (LMICs), the prevalence of inadequate micronutrient intake and micronutrient deficiency is high, particularly among women and young children. Sub-Saharan Africa is disproportionally affected by micronutrient deficiencies (MNDs) and the progress towards sustained reduction in MNDs has been limited. In recent years, large-scale food fortification has gained traction in LMICs, including sub-Saharan African countries, to address micronutrient deficiency. Given the long-term effort and investment that is needed to implement and sustain fortification programs, dietary intake data should be used in overall planning of fortification programs to make informed judgments about the appropriateness of the food vehicle, and the types and amounts of the specific nutrients to be added. Simulation studies provide insights about the potential contributions of food fortification to micronutrient intakes and, alongside information on program costs, can provide an efficient way of comparing hypothetical fortification scenarios that can then be translated into nutrition policies and practices. However, the usefulness of simulation modeling studies depends on the validity of dietary requirements applied and assumptions taken into consideration.
Zinc Nutrient Reference Values (NRVs) set by several expert groups differ widely. The effects of these differences on the predicted impacts and on the cost-effectiveness of zinc fortification programs have not been fully explored. In the first study, we estimated the prevalence of inadequate zinc intake and the predicted impact and cost-effectiveness of zinc fortification programs using NRVs published by different authorities based on data from a nationally representative nutrition survey among children and women in Cameroon. The distribution of usual zinc intakes was estimated using the National Cancer Institute (NCI) method. Prevalence of total zinc intake below the estimated average requirement (i.e. dietary requirement) and prevalence of “absorbable zinc intake” below the physiological requirement were estimated using NRVs from 4 expert groups: World Health Organizations (WHO), Institute of Medicine (IOM), International Zinc Nutrition Consultative Group (IZiNCG) and European Food Safety Authority (EFSA). The estimated prevalence of inadequate zinc intake varied substantially ranging from 10% (IZiNCG-physiological requirement) to 81% (EFSA-physiological requirement) among children, and from 9.4% (WHO-physiological requirement) to 94% (IOM-physiological requirement) among women. These differences observed in the prevalence of inadequate intake translated to differences in the estimated benefits and cost-effectiveness of zinc fortification programs. Therefore, depending on the NRVs applied, assessments will differ regarding the need for, and the benefits and cost-effectiveness of, zinc fortification programs. Efforts are needed to harmonize NRVs for zinc.
Snack products that are voluntarily fortified with micronutrients are increasingly available but are not necessarily formulated to meet known dietary nutrient gaps, so the potential impacts on population micronutrient intake adequacy are uncertain. In the second study, we predicted the impacts of hypothetical micronutrient-fortified biscuits on inadequate micronutrient intake among children and women of reproductive age (WRA) based on nationally representative data in Cameroon. We estimated usual nutrient intake distributions using the NCI method and simulated the impacts of biscuit fortification on prevalence of micronutrient intake (vitamin A (VA), folate, vitamin B-12, iron, and zinc) below the estimated average requirement, given observed biscuit consumption, in the presence and absence of large-scale food fortification (LSFF) programs. In the absence of LSFF programs, biscuits fortified with retinol (600μg/100g), folic acid (300μg/100g), and zinc (8mg/100g) were predicted to reduce the prevalence of inadequacy among children by 10.3 ± 4.4, 13.2 ± 4.2 and 12.0 ± 6.1 percentage points, respectively, in Yaoundé/Douala. However, when the impact of existing national VA-fortified oil, and folic acid and zinc-fortified wheat flour programs were considered, the additional impacts of fortified biscuits were reduced substantially. Micronutrient-fortified biscuits were predicted to have minimal impacts on dietary inadequacy among WRA, with or without LSFF programs. Given observed patterns of biscuit consumption in Cameroon, biscuit fortification is unlikely to reduce dietary inadequacy of studied micronutrients, except possibly for selected nutrients among children in urban areas, but only in the absence of LSFF programs.
Zambia has been implementing mandatory sugar fortification with VA, however the contribution of VA-fortified sugar to VA intakes and status has not been directly assessed. In the third study, we predicted the potential impacts of sugar fortification with VA on prevalence of VA inadequacy, and examine its association with plasma and breast milk retinol among lactating women based on baseline data from a randomized trial from Mkushi District in rural Zambia. We simulated VA intake under various sugar fortification scenarios: 3.1 and 8.8 mg/kg (measured median fortification levels of VA in sugar from previous studies), 10 mg/kg (minimum legal requirement) and 15 mg/kg (minimum legal requirement at factory level). We applied the NCI’s bivariate model to examine associations of usual intake of sugar and dietary VA with plasma and breast milk retinol concentrations measured by high performance liquid chromatography.
Our model predicted that sugar fortification with VA at 3.1 mg/kg, 8.8 mg/kg, 10 mg/kg and 15 mg/kg would reduce the prevalence of VA inadequacy by 7 (SE:6), 24 (SE:14), 30 (SE:15) and 47 (SE:18) percentage points, respectively, without increasing the risk of retinol intake above the UL. Usual sugar intake and usual VA intake were not associated with plasma retinol (β = 0.003; 95% CI: -0.015, 0.020) or with breastmilk retinol concentrations (β = 0.012; 95% CI: -0.002, 0.026). Usual VA intake from other foods sources was significantly associated with the log of breast milk retinol in µmol/ L (β = 0.001; 95% CI: 0.0002, 0.002), but not with plasma retinol (β = -0.0001; 95% CI: -0.001, 0.001). In Zambia, sugar fortification has the potential to reduce dietary VA inadequacy. However, the impacts on VA intakes and any improvements in VA status are likely to be limited if the program is not implemented as planned. Even if target fortification levels are achieved (10 mg/kg), sugar fortification alone is unlikely to eliminate dietary VA inadequacy among lactating women in Zambia.
Together, the three studies from the dissertation provide evidence on the effect of using different zinc reference values on the predicted benefits and cost-effectiveness of zinc fortification programs, and the impacts of voluntary snack food fortification and mandatory sugar fortification on prevalence of inadequate intake. These findings have important implications with regard to planning and evaluation of fortification programs in LMIC contexts.
Khat Chewing Practice and Associated Factors among Adults in Ethiopia: Further Analysis Using the 2011 Demographic and Health Survey.
No full textBackgroundKhat chewing has become a highly prevalent practice and a growing public health concern in Ethiopia. Although there have been many small scale studies, very limited national information has been available in the general population. This study aimed to identify factors associated with khat chewing practice among Ethiopian adults.MethodsThe study used the 2011 Ethiopian demographic and health survey data. The survey was cross-sectional by design and used a multistage cluster sampling procedure. Bivariate and multivariable logistic regression models with adjusted odds ratio (AOR) and their 95% confidence intervals (CI) were used to quantify the predictors.ResultsThe overall khat chewing prevalence was 15.3% (95% CI: 14.90-15.71). Regional variation was observed with the highest in Harari [(53.2% (95% CI: 43.04-63.28)] and lowest in Tigray regional state [(1.1% (95% CI: 0.72-1.66)]. Multivariable analysis showed that Islam followers were 23.8 times more likely to chew khat as compared to Orthodox followers. Being a resident in Oromiya, South Nation, Nationalities and People (SNNP), Gambella, Harari and Dire Dawa regions had 1.9, 1.6, 3.1, 5.2 and 3.5 times higher odds of chewing khat as compared to Addis Ababa residents, respectively. Adults in the age group 45-49 years were 3.6 times more likely to chew khat as compared to 15-19 years. The middle and richest wealth quintiles were 1.3 and 1.5 times more likely to chew khat, respectively, as compared to the poorest category. Rural residents had 1.3 odds of chewing khat than urban residents. Those individuals who had occupation in sales, agriculture, service sector, skilled and unskilled manual workers were 1.6, 1.3, 2.4, 1.7 and 2.3 times more likely to chew khat, respectively, as compared to those who have no occupation. Females were 77% less likely to chew khat as compared to males. Formerly married and those experienced in child death had 1.4 and 1.2 times higher odds to chew khat as compared with those never married and never had child death, respectively. Those who attended mass media were 1.4 times more likely to chew khat compared with not attended.ConclusionKhat chewing is a public health concern in Ethiopia. The highest wealth quintiles, older age group, rural residence, child death, formerly married, males, regions of Oromiya, SNNP, Gambella, Harari and Dire Dawa and Islamic followers had statistically significant association with khat chewing. Due attention needs to be given for these factors in any intervention procedures
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Tobacco use and associated factors among adults in Ethiopia: further analysis of the 2011 Ethiopian Demographic and Health Survey
No full textPrevalence of antenatal depression and associated factors among pregnant women in Addis Ababa, Ethiopia: a cross-sectional study
No full textDispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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