132,292 research outputs found
Relationship between vaccination and nutritional status in children: Analysis of recent demographic and health surveys
No full textBACKGROUND A body of evidence suggests that vaccines support the development of the immune system and also improve overall health. OBJECTIVE To study the effect of the complete basic vaccination schedule (Bacille Calmette-Guerin, i.e., BCG; measles; polio 3; and Diphtheria, Tetanus toxoids, and Pertussis, i.e., DTP3) on nutritional status of children under 2 years of age. METHODS Recent DHS data from 16 countries conducted after 2013 were used. After a bivariate descriptive analysis, a logistic regression analysis was conducted to predict the likelihood of underweight, stunting, and wasting by immunization status. A combined odds ratio was computed and adjusted for background variables. RESULTS A significantly higher prevalence of underweight was found among children with incomplete vaccination schedules in seven countries. Similarly, wasting and stunting were frequently observed in under-vaccinated children in four countries. Moreover, logistic regression adjusted for background variables revealed a relation between incomplete vaccination and underweight in Angola, Chad, and Guatemala (95% CI lower bound > 1). Combining data of all countries, underweight (adjusted Odds Ratio, aOR 1.21, 95% CI 1.11-1.31), wasting (aOR 1.18, 95% CI 1.05-1.33), and stunting (aOR 1.07, 95% CI 1.00-1.14) were associated with poor vaccination status. The overall effect was consistent with both sexes except the results for wasting for females and stunting for males, though insignificant. CONTRIBUTION To our knowledge, this is the first paper assessing the relation between vaccination and nutritional status at a multi-country level with a huge dataset. Our analysis suggests a poor nutritional status in children with an incomplete vaccination schedule
Donation programme of returned medicines: Role of donors and point of view of beneficiaries
No full textBackground: Donation of returned medicines is a debated health policy issue as it is discouraged by WHO, but accepted in some countries. Methods: Lessons learned from a donation programme of returned medicines carried out in Europe were documented. Results: The donation programme we reviewed followed a strict protocol for collection, sorting and distribution of returned drugs, in order to avoid the major limitations associated with unused medicine donations. Over a period of 3 years, 23 145 boxes of medicines were donated to 14 organizations operating in Europe, Africa and Latin America. Conclusions: The donations covered about one-third of the volume of medicines used by beneficiary organizations. The programme helped to decrease expenditure by both patients and health facilities
Curved Track Analysis of FSO Link for Ground-to-Train Communications
No full textIn this work, a free space optical (FSO) link for the ground-to-train (G2T-FSO) communications is proposed. Analytical analysis is carried out for the curved rail tracks. We show that the transmitter divergence angle, the transmit power and the size of the concentration lens need to increase for the curved section of the rail track compared to the straight track. We derive the analytical expression for the received power level based on the link geometry for the case of the curved track In the worst case scenario when the curvature radius is 120 m, the transmit power at the optical base station (BS) needs to increase by over 2 dB when the concentration lens radius is increased by 5 times. Analyses also show that the received power along the track increases with the curvature radius for the same transmit power and receiver optics illustrating the effect due to link geometry. Additionally, the signal-to-noise ratio (SNR) and the bit error rate (BER) performance of the system for the curved track with different curvature radii is analysed at data rates of 10 Mbps and 100 Mbps for an additive white Gaussian noise (AWGN) channel showing a good agreement between the theoretical and the simulated BER. Finally, effect of scintillations on the G2T-FSO link performance is discussed
Assessing the Performance of Bamboo Structural Components
No full textBamboo has been a traditional construction material in many regions for centuries. The rapid growth and maturation rate of bamboo as well as its good strength properties and global accessibility make it a promising non-conventional building material resource. However, due to limited standardization and design criteria, bamboo has often been relegated to non-engineered and marginally-engineered construction. The current study assesses the performance of full-culm structural bamboo components and appropriate standard material and member test methods. A brief overview is given to the motivation for the study of structural bamboo, placing the work in its social context, followed by background on the properties of bamboo and the structural applications of the material as well as the pathway to its further standardization and utilization. Experimental and analytical studies are conducted focusing on the tensile, flexural, buckling, and environmental sustainability performance of full-culm bamboo components. Standard bamboo tension tests are carried out to investigate the test interferences associated with the functionally graded fiber distribution across the culm wall thickness. Tension specimens oriented in both the radial and tangential directions are considered in order to isolate the effects of the fiber gradation both on test results and experimental methodology. Recognizing longitudinal splitting induced by flexure as a dominant limit state, modified standard bamboo flexural tests are performed to investigate the development of a standard test procedure for this limit state, which involves a mixed-mode longitudinal splitting failure in the flexural element. Flexural testing considers two test configurations and three difference species of bamboo. Results of modified full-culm tests are compared with smaller clear bamboo flexural specimens taken from the culm wall as well as standard or proposed tests for pure mode I and pure mode II failure components. The experimental buckling capacity of single-culm and multiple-culm bamboo columns is studied as further understanding of column strength is critical to the construction of more robust and potentially multiple-story bamboo structures. Finally, in an effort to quantify the perceived sustainability benefits of bamboo, the environmental impacts of multiple-culm bamboo columns are compared with structurally comparable timber and steel alternatives in a comparative midpoint life cycle analysis
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Serum 25-hydroxyvitamin D and cognitive decline in the very old: The Newcastle 85+ study
No full textBackground and purpose:
Studies investigating the association between 25-hydroxyvitamin D [25(OH)D] and cognition in the very old (85+) are lacking.
Methods:
Cross-sectional (baseline) and prospective data (up to 3 years follow-up) from 775 participants in the Newcastle 85+ Study were analysed for global (measured by the Standardized Mini-Mental State Examination) and attention-specific (measured by the attention battery of the Cognitive Drug Research test) cognitive performance in relation to season-specific 25(OH)D quartiles.
Results:
Those in the lowest and highest season-specific 25(OH)D quartiles had an increased risk of impaired prevalent (1.66, 95% confidence interval 1.06–2.60, P = 0.03; 1.62, 95% confidence interval 1.02–2.59, P = 0.04, respectively) but not incident global cognitive functioning or decline in functioning compared with those in the middle quartiles adjusted for sociodemographic, health and lifestyle confounders. Random effects models showed that participants belonging to the lowest and highest 25(OH)D quartiles, compared with those in the middle quartiles, had overall slower (log-transformed) attention reaction times for Choice Reaction Time (lowest, b = 0.023, P = 0.01; highest, b = 0.021, P = 0.02), Digit Vigilance Task (lowest, b = 0.009, P = 0.05; highest,b = 0.01, P = 0.02) and Power of Attention (lowest, b = 0.017, P = 0.02;highest, b = 0.022, P = 0.002) and greater Reaction Time Variability (lowest,b = 0.021, P = 0.02; highest, b = 0.02, P = 0.03). The increased risk of worse global cognition and attention amongst those in the highest quartile was not observed in non-users of vitamin D supplements/medication.
Conclusion:
Low and high season-specific 25(OH)D quartiles were associated with prevalent cognitive impairment and poorer overall performance in attention-specific tasks over 3 years in the very old, but not with global cognitive decline or incident impairment
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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