oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 20 )

2019 ( 220 )

2018 ( 286 )

2017 ( 288 )

Custom range...

Search Results: 1 - 10 of 149805 matches for " H. Bolland "
All listed articles are free for downloading (OA Articles)
Page 1 /149805
Display every page Item
Technical Efficiency Across Agro-Ecological Zones in Ethiopia: The Impact of Poverty and Asset Endowments
Bamlaku A. Alemu,E.A. Nuppenau,H. Bolland
Agricultural Journal , 2013,
Abstract: Currently, Ethiopia focuses on agriculture so that it can spur growth in other sectors of the economy. In order to help policy makers understand factors affecting agriculture, studies on efficiency are important. Especially, the impact of poverty and asset endowments could be highly pronounced in an agrarian country such as Ethiopia. In this regard, the objectives of this study are two fold: to investigate efficiency variations across agro-ecological zones and to examine the impacts of poverty and asset endowments on inefficiency in the study area. Data were collected from 254 randomly selected households. Stochastic frontier production function was estimated and the results of the analysis revealed a mean technical efficiency of 75.68%. F-test also showed a statistically significant difference in technical efficiency among agro-ecological zones. On the other hand, maximum likelihood estimates indicated positive and significant elasticities for asset endowments including physical (land and draft power), financial (credit access and market) and human (labor and education). However, poverty was found to reduce efficiency levels significantly. Thus, future endeavoers should envisage better market and education access and reduced liquidity constraints.
Does Missing Data in Studies of Hard-to-Reach Populations Bias Results? Not Necessarily  [PDF]
Anneliese C. Bolland, Sara Tomek, John M. Bolland
Open Journal of Statistics (OJS) , 2017, DOI: 10.4236/ojs.2017.72021
Abstract: Missing data are always an issue in community-based longitudinal studies, calling into question the representativeness of samples and bias in conclusions, the research has generated. This may be due to the difficulty of implementing random sampling procedures in these studies and/or the inherent difficulty in sampling hard-to-reach segments of the population being studied. In fact, the ability to accurately study hard-to-reach populations in light of potential bias created by missing data remains an open question. In this study, missing data are defined as both failure to interview potential research participants identified in the sampling frame and failure to retain enrolled research participants longitudinally. Using the sample from the Mobile Youth Survey, a multiple-cohort, longitudinal study of adolescents living in highly impoverished neighborhoods in Mobile, Alabama, we examined sample representativeness and dropout to determine whether missing data led to a nonrepresentative, and therefore, biased sample. Results indicate that even though random procedures are not strictly used to draw the sample, (a) the sample appears to be largely representative of the population that was studied, and (b) attrition is largely uncorrelated with characteristics of those who dropped out. This suggests that it is possible to study with validity hard-to reach populations in community settings.
Steam bottoming cycles offshore - Challenges and possibilities
Lars O. Nord,Olav Bolland
Journal of Power Technologies , 2012,
Abstract: This paper addresses the challenges and possibilities related to offshore steam bottoming cycles with a special focus on once-through heat recovery steam generators (HRSGs). The main focus of the paper is to investigate the compromise between weight and efficiency of the HRSG by process simulation. The cost per installed kg of equipment is high offshore. Therefore, any bottoming cycle, applied to the back-end of the gas turbine, needs to be compact, yet sufficiently efficient. Important parameters to make the HRSG compact were the number of steam pressure levels, the HRSG technology, the flue gas pressure drop in the HRSG, and the pinch-point temperature difference. While selecting the parameters as a compromise between weight and efficiency, the combined cycle net plant efficiency was found to be approximately 50% with a power output of 43 MW. The steam turbine gross power output was 11 MW or about 25% of the total combined cycle plant gross power output. These results were compared to an onshore reference plant model which utilized the same type of aeroderivative gas turbine. The weight of the offshore once-through HRSG was about one third of the onshore HRSG. The net plant efficiency was 3%-points lower for the offshore system.
Developmental assets and age of first sexual intercourse among adolescent African American males in Mobile, Alabama  [PDF]
Shannon Talbott, Jessica W. Henderson, Linda Stonecipher, John Bolland, Brad Lian
Health (Health) , 2013, DOI: 10.4236/health.2013.56A3005
Abstract:

Background and Aims: Younger age at first sexual intercourse is associated with a variety of adverse health outcomes. We aimed to gain a clearer understanding of a wide range of individual, family and social factors that may influence sexual behavior of children and adolescents. Specifically, we examined the relationships of developmental assets with age of first sexual intercourse among a large sample (n = 1061) of adolescent African American males living in low-income neighborhoods in Mobile, Alabama. Methods: Using the Developmental Asset Model as a theoretical guide, we selected variables from adolescent survey data and conducted logistic regression analysis to determine predictors of early age of first sexual intercourse. Results: Nearly one half (49%) of the male survey participants reported that they first had sexual intercourse at the age of 12 or younger. The total number of assets was the strongest predictor of later age (13 years old or later) of first sexual intercourse (OR 1.49, 95% CI = 1.09, 2.04), followed by decision-making skills (OR 1.40, 95% CI = 1.04, 1.86), and positive view of the future (OR 1.36, 95% CI = 1.02, 1.74). Conclusion: There are several developmental assets related to the age of first sexual intercourse. This study found support for the Developmental Asset Model as a framework for promoting sexual and overall adolescent health. Recommendations for asset-building among this population are discussed.

Book Reviews
Rita Bolland,Alfred Bühler,Raymond Buve,Hugo G. Nutini
Bijdragen tot de Taal-, Land- en Volkenkunde , 1982,
Abstract: - Rita Bolland, Alfred Bühler, The patola of Gujarat. Double ikat in India. Krebs AG Basel, 1979. Vol. 1, 360 p. tekst, ill. Vol. 2, afb. in kleur en zwart/wit, krt. tab. noten, verkl. woorden. litl., Eberhard Fischer (eds.) - Raymond Buve, Hugo G. Nutini, Ritual kinship. The structure and historical development of the Compadrazgo system in rural Tlaxcala, Vol. I. Princeton University Press, N.J., 1980, XVI plus 494 pp., maps, tables, glossary and index., Betty Bell (eds.) - Benno Galjart, G.A. Banck, Jagen met een kat... Schaarse middelen en sociale relaties in de Braziliaanse staat Espirito Santo, CEDLA Incidentele publicaties no. 8, CEDLA, Amsterdam 1977. - R.A.L.H. Gunawardana, J. van Goor, Jan Kompanie as schoolmaster: Dutch education in Ceylon, 1690-1795, Historische Studies, Instituut voor Geschiedenis der Rijksuniversiteit te Utrecht, XXIV, Wolters-Noordhoff Groningen, 1978, 205 pp., 3 maps. - Ria Kloppenborg, R.A.L.H. Gunawardana, Robe and plough. Monasticism and economic interest in early medieval Sri Lanka. Association for Asian Studies, Monographs and Papers No. XXXV, University of Arixona Press, Tucson, Arizona, 1979; 377 pages, including bibliography and index. - Els Postel-Coster, Jan van Bremen, Romantropologie - Essays over antropologie en literatuur, Antropologisch-Sociologisch Centrum Universiteit van Amsterdam, 1979., Sjaak van der Geest, Jojada Verrips (eds.) - Arie de Ruijter, T. Lemaire, Over de waarde van kulturen. Een inleiding in de kultuurfilosofie. Ambo, Baarn 1976, herdruk 1980. 509 blz. - P. van de Velde, W. Arens, The man-eating myth. Oxford University Press, New York, 1979. XIV + 206 pp., 12 illustrations. - E.Ch.L. van der Vliet, Klaus E. Müller, Geschichte der antiken ethnographie und ethnologischen theoriebildung von den anf ngen bis auf die byzantinischen historiographen, Teil II (Studien zur Kulturkunde 52), Wiesbaden: Franza Steiner Verlag, 1980. 563 pp. 11 figs. - J.J. de Wolf, P.T.W. Baxter, Age, generation and time: Some features of East African age organisations. C. Hurst and Co., London 1978., Uri Almagor (eds.) - J.J. de Wolf, Myrtle S. Langley, The Nandi of Kenya: Life crisis rituals in a period of change. C. Hurst and Co., London 1979.
Osteomalacia in an HIV-infected man receiving rifabutin, a cytochrome P450 enzyme inducer: a case report
Mark J Bolland, Andrew Grey, Anne M Horne, Mark G Thomas
Annals of Clinical Microbiology and Antimicrobials , 2008, DOI: 10.1186/1476-0711-7-3
Abstract: A 59 year old man treated with zidovudine, lamivudine, indinavir, and ritonavir for infection with human immunodeficiency virus volunteered to take part in a study of bone loss. He was found to have vitamin D insufficiency with secondary hyperparathyroidism and received vitamin D and calcium supplementation. He suffered a recurrence of infection with Mycobacterium avium intracellulare for which he received treatment with ciprofloxacin, rifabutin, and ethambutol. Subsequently, he developed worsening vitamin D deficiency with hypocalcaemia, secondary hyperparathyroidism and elevated markers of bone turnover culminating in an osteomalacic vertebral fracture. Correction of the vitamin D deficiency required 100,000 IU of cholecalciferol monthly.Rifabutin is a cytochrome P450 inducer, and vitamin D and its metabolites are catabolised by cytochrome P450 enzymes. We therefore propose that treatment with rifabutin led to the induction of cytochrome P450 enzymes catabolising vitamin D, thereby causing vitamin D deficiency and osteomalacia. This process might be mediated through the steroid and xenobiotic receptor (SXR).Treatment with rifabutin induces the cytochrome P450 enzymes that metabolise vitamin D and patients treated with rifabutin might be at increased risk of vitamin D deficiency. In complex medication regimens involving agents that induce or inhibit cytochrome P450 enzmyes, consultation with a clinical pharmacist or pharmacologist may be helpful in predicting and/or preventing potentially harmful interactions.Medications that induce or inhibit cytochrome P450 enzymes are commonly prescribed and therefore drug interactions mediated by changes in these enzymes are also common. People infected with human immunodeficiency virus (HIV) are frequently treated with complex medical regimens containing a number of medications that can induce or inhibit cytochrome P450 enzymes. We present a case of osteomalacia in an HIV-infected man that was likely caused by cytochrome P450-
La conformación del paisaje y el aprovechamiento de los recursos naturales por las comunidades mayas de La Monta?a, Hopelchén, Campeche
Porter-Bolland, Luciana;Sánchez González, María Consuelo;Ellis, Edward Alan;
Investigaciones geográficas , 2008,
Abstract: this manuscript provides a landscape history analysis for the region of la monta?a, located at the municipality of hopelchen of the state campeche, mexico. the information was obtained through a literature review on historic sources and complemented with information provided by the local inhabitants. also, a characterization is provided regarding the population's current situation, including their productive systems. this region is comprised of eight ejidoswhose mayan population has a history of land use of at least 3 000 years. the structure and composition of the landscape has been molded by natural and social factors. changes in population densities and internal migration have occurred constantly. current history indicates that the fluctuating population has varied from 14 400 inhabitants in 1860 to less than 5 000 in 2005. in spite of today's low population densities, recent productive activities are turning to be more agricultural oriented, modifying the structure and composition at the landscape level. investment in the region is needed both, in economic terms and for strengthening social capital in order to promote productive activities that are ecological and socially sound, improving the welfare of local inhabitants without compromising its natural resources. the acceptance of this mayan territory should be consensual, as one in which local inhabitants have the right to actively participate in development processes and not merely as cheap manual labor.
La conformación del paisaje y el aprovechamiento de los recursos naturales por las comunidades mayas de La Monta a, Hopelchén, Campeche
Luciana Porter-Bolland,María Consuelo Sánchez González,Edward Alan Ellis
Investigaciones geográficas , 2008,
Abstract: Se presenta un análisis de la historia de uso del suelo en la región de La Monta a, municipio de Hopelchén, Campeche, realizado a partir de una recopilación de la documentación histórica existente, complementado con información proporcionada por habitantes del lugar. De igual forma, se presenta una caracterización de la población actual y sus sistemas productivos, utilizando información obtenida mediante encuestas, entrevistas y talleres. La Monta a comprende ocho ejidos cuya población maya-hablante tiene una historia de uso de los recursos naturales de más de tres mil a os. La estructura y composición del paisaje en esta zona han sido moldeadas por diferentes factores tanto naturales como sociales, estos últimos guiados por intereses tanto internos como externos. Los cambios poblacionales y los movimientos migratorios internos han sido una de las constantes de la región, con una población maya de 14 400 habitantes en 1860, que disminuyó a menos de 5 000 en el 2005. A pesar de la baja densidad poblacional, las actividades productivas recientes están adquiriendo un carácter más agropecuario, modificando la estructura y composición del paisaje. Como propuesta para mejorar la calidad de vida de los pobladores de la región sin comprometer la riqueza natural de la zona, se requiere una inversión tanto en capital social como en términos económicos, para poder impulsar prácticas de manejo que sean ecológica y socialmente sostenibles. El reconocimiento de este territorio maya debe ser consensual, donde los pobladores locales participen de forma activa en el proceso de desarrollo de la región y no como mano de obra barata en la explotación no sustentable de la selva.
Press Releases Issued by Supplements Industry Organisations and Non-Industry Organisations in Response to Publication of Clinical Research Findings: A Case-Control Study
Michael T. M. Wang, Greg Gamble, Mark J. Bolland, Andrew Grey
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0101533
Abstract: Background Dietary supplement use is increasing despite lack of evidence of benefits, or evidence of harm. Press releases issued by the supplements industry might contribute to this situation by using ‘spin’ (strategies to hype or denigrate findings) to distort the results of clinical studies. We assessed press releases issued in response to publication of clinical studies on dietary supplements. Methods and Findings We analyzed 47 supplements industry press releases and 91 non-industry press releases and news stories, generated in response to 46 clinical studies of dietary supplements published between 1/1/2005 and 5/31/2013. The primary outcome was ‘spin’ content and direction. We also assessed disposition towards use of dietary supplements, reporting of study information, and dissemination of industry press releases. More supplements industry press releases (100%) contained ‘spin’ than non-industry media documents (55%, P<0.001). Hyping ‘spin’ scores were higher in industry than non-industry media documents for studies reporting benefit of supplements (median ‘spin’ score 3.3, 95% CI 1.0–5.5 vs 0.5, 0–1.0; P<0.001). Denigratory ‘spin’ scores were higher in industry than non-industry media documents for studies reporting no effect (6.0, 5.0–7.0 vs 0, 0–0; P<0.001) or harm (6.0, 5.5–7.5 vs 0, 0–0.5; P<0.001) from a supplement. Industry press releases advocated supplement use in response to >90% of studies that reported no benefit, or harm, of the supplement. Industry press releases less frequently reported study outcomes, sample size, and estimates of effect size than non-industry media documents (all P<0.001), particularly for studies that reported no benefit of supplements. Industry press releases were referenced by 148 news stories on the websites of 6 organizations that inform manufacturers, retailers and consumers of supplements. Conclusions Dietary supplements industry press releases issued in response to clinical research findings are characterized by ‘spin’ that hypes results that are favourable to supplement use and denigrates results that are not.
The Impact of Genetic Susceptibility to Systemic Lupus Erythematosus on Placental Malaria in Mice
Michael Waisberg, Christina K. Lin, Chiung-Yu Huang, Mirna Pena, Marlene Orandle, Silvia Bolland, Susan K. Pierce
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0062820
Abstract: Severe malaria, including cerebral malaria (CM) and placental malaria (PM), have been recognized to have many of the features of uncontrolled inflammation. We recently showed that in mice genetic susceptibility to the lethal inflammatory autoimmune disease, systemic lupus erythematosus (SLE), conferred resistance to CM. Protection appeared to be mediated by immune mechanisms that allowed SLE-prone mice, prior to the onset of overt SLE symptoms, to better control their inflammatory response to Plasmodium infection. Here we extend these findings to ask does SLE susceptibility have 1) a cost to reproductive fitness and/or 2) an effect on PM in mice? The rates of conception for WT and SLE susceptible (SLEs) mice were similar as were the number and viability of fetuses in pregnant WT and SLEs mice indicating that SLE susceptibility does not have a reproductive cost. We found that Plasmodium chabaudi AS (Pc) infection disrupted early stages of pregnancy before the placenta was completely formed resulting in massive decidual necrosis 8 days after conception. Pc-infected pregnant SLEs mice had significantly more fetuses (~1.8 fold) but SLE did not significantly affect fetal viability in infected animals. This was despite the fact that Pc-infected pregnant SLEs mice had more severe symptoms of malaria as compared to Pc-infected pregnant WT mice. Thus, although SLE susceptibility was not protective in PM in mice it also did not have a negative impact on reproductive fitness.
Page 1 /149805
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.