136 research outputs found
Bias in the news: network television coverage of the 1972 election campaign
(print) xv, 213 p. ; 26 cmPreface xiii -- 1. Bias and News Programming 3 -- 2. Studying News Coverage of the 1972 Campaign 17 -- 3. How the Candidates Fared during the Campaign 47 -- 4. Issue Coverage during the Campaign 77 -- 5. Political Parties in the 1972 Campaign Coverage 111 -- 6. Alternative Techniques of Analysis : Ratings and Themes 145 -- 7. Specific Issues and Sources in News Coverage 165 -- 8. Campaign 1972 through the Eyes of Television News 187 -- Index 20
Antagonisms, mutualisms and commensalisms affect outbreak dynamics of the southern pine beetle
Feedback from community interactions involving mutualisms are a rarely explored mechanism for generating complex population dynamics. We examined the effects of two linked mutualisms on the population dynamics of a beetle that exhibits outbreak dynamics. One mutualism involves an obligate association between the bark beetle, Dendroctonus frontalis and two mycangial fungi. The second mutualism involves Tarsonemus mites that are phoretic on D. frontalis ( commensal ), and a blue-staining fungus, Ophiostoma minus. The presence of O. minus reduces beetle larval survival ( antagonistic ) by outcompeting beetle-mutualistic fungi within trees yet supports mite populations by acting as a nutritional mutualist. These linked interactions potentially create an interaction system with the form of an endogenous negative feedback loop. We address four hypotheses: (1) Direct negative feedback: Beetles directly increase the abundance of O. minus, which reduces per capita reproduction of beetles. (2) Indirect negative feedback: Beetles indirectly increase mite abundance, which increases O. minus, which decreases beetle reproduction. (3) The effect of O. minus on beetles depends on mites, but mite abundance is independent of beetle abundance. (4) The effect of O. minus on beetles is independent of beetle and mite abundance. High Tarsonemus and O. minus abundances were strongly correlated with the decline and eventual local extinction of beetle populations. Manipulation experiments revealed strong negative effects of O. minus on beetles, but falsified the hypothesis that horizontal transmission of O. minus generates negative feedback. Surveys of beetle populations revealed that reproductive rates of Tarsonemus, O. minus, and beetles covaried in a manner consistent with strong indirect interactions between organisms. Co-occurrence of mutualisms embedded within a community may have stabilizing effects if both mutualisms limit each other. However, delays and/ or non-linearities in the interaction systems may result in large population fluctuations. © Springer-Verlag 2005
South Korean Military Service Promotes Smoking: A Quasi-Experimental Design
∙ The authors have no financial conflicts of interest. © Copyright: Yonsei University College of Medicine 2012 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Licens
Randomized Trial to Reduce Air Particle Levels in Homes of Smokers and Children
Introduction Exposure to fine particulate matter in the home from sources such as smoking, cooking, and cleaning may put residents, especially children, at risk for detrimental health effects. A randomized clinical trial was conducted from 2011 to 2016 to determine whether real-time feedback in the home plus brief coaching of parents or guardians could reduce fine particle levels in homes with smokers and children. Design A randomized trial with two groups—intervention and control. Setting/participants A total of 298 participants from predominantly low-income households with an adult smoker and a child aged \u3c14 years. Participants were recruited during 2012–2015 from multiple sources in San Diego, mainly Women, Infants and Children Program sites. Intervention The multicomponent intervention consisted of continuous lights and brief sound alerts based on fine particle levels in real time and four brief coaching sessions using particle level graphs and motivational interviewing techniques. Motivational interviewing coaching focused on particle reduction to protect children and other occupants from elevated particle levels, especially from tobacco-related sources. Main outcome measures In-home air particle levels were measured by laser particle counters continuously in both study groups. The two outcomes were daily mean particle counts and percentage time with high particle concentrations (\u3e15,000 particles/0.01 ft3). Linear mixed models were used to analyze the differential change in the outcomes over time by group, during 2016–2017. Results Intervention homes had significantly larger reductions than controls in daily geometric mean particle concentrations (18.8% reduction vs 6.5% reduction, p\u3c0.001). Intervention homes’ average percentage time with high particle concentrations decreased 45.1% compared with a 4.2% increase among controls (difference between groups p\u3c0.001). Conclusions Real-time feedback for air particle levels and brief coaching can reduce fine particle levels in homes with smokers and young children. Results set the stage for refining feedback and possible reinforcing consequences for not generating smoke-related particles. Trial registration This study is registered at www.clinicaltrials.gov NCT01634334
Spectral statistics near the quantum percolation threshold
The statistical properties of spectra of a three-dimensional quantum bond
percolation system is studied in the vicinity of the metal insulator
transition. In order to avoid the influence of small clusters, only regions of
the spectra in which the density of states is rather smooth are analyzed. Using
finite size scaling hypothesis, the critical quantum probability for bond
occupation is found to be while the critical exponent for the
divergence of the localization length is estimated as . This
later figure is consistent with the one found within the universality class of
the standard Anderson model.Comment: REVTeX, 4 pages, 5 figures, all uuencoded, accepted for publication
in PRB (Rapid Communication
Perceived neighborhood environment and physical activity in 11 countries: Do associations differ by country?
Background: Increasing empirical evidence supports associations between neighborhood environments and physical activity. However, since most studies were conducted in a single country, particularly western countries, the generalizability of associations in an international setting is not well understood. The current study examined whether associations between perceived attributes of neighborhood environments and physical activity differed by country. Methods: Population representative samples from 11 countries on five continents were surveyed using comparable methodologies and measurement instruments. Neighborhood environment × country interactions were tested in logistic regression models with meeting physical activity recommendations as the outcome, adjusted for demographic characteristics. Country-specific associations were reported. Results: Significant neighborhood environment attribute × country interactions implied some differences across countries in the association of each neighborhood attribute with meeting physical activity recommendations. Across the 11 countries, land-use mix and sidewalks had the most consistent associations with physical activity. Access to public transit, bicycle facilities, and low-cost recreation facilities had some associations with physical activity, but with less consistency across countries. There was little evidence supporting the associations of residential density and crime-related safety with physical activity in most countries. Conclusion: There is evidence of generalizability for the associations of land use mix, and presence of sidewalks with physical activity. Associations of other neighborhood characteristics with physical activity tended to differ by country. Future studies should include objective measures of neighborhood environments, compare psychometric properties of reports across countries, and use better specified models to further understand the similarities and differences in associations across countries
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A randomized controlled trial of orthodontist-based brief advice to prevent child obesity
Objective: We conducted a randomized controlled trial to test whether brief exercise and diet advice provided during child patient visits to their orthodontic office could improve diet, physical activity, and age-and-genderadjusted BMI.
Methods: We enrolled orthodontic offices in Southern California and Tijuana, Mexico, and recruited their patients aged 8-16 to participate in a two-year study. At each office visit, staff provided the children with "prescriptions" for improving diet and exercise behaviors. Multilevel models, which adjusted for clustering, determined differential group effects on health outcomes, and moderation of effects.
Results: We found differential change in BMI favoring the intervention group, but only among male participants (p < 0.001; Cohen's d = 0.085). Of four dietary variables, only junk food consumption changed differentially, in favor of the intervention group (p = 0.020; d = 0.122); the effect was significant among overweight/obese (p = 0.001; d = 0.335) but not normal weight participants. Physical activity declined non-differentially in both groups and both genders.
Conclusion: The intervention, based on the Geoffrey Rose strategy, had limited success in achieving its aims
Diagnostic criteria and symptom grading for delayed gastric conduit emptying after esophagectomy for cancer: international expert consensus based on a modified Delphi process
Delayed gastric conduit emptying (DGCE) after esophagectomy for cancer is associated with adverse outcomes and troubling symptoms. Widely accepted diagnostic criteria and a symptom grading tool for DGCE are missing. This hampers the interpretation and comparison of studies. A modified Delphi process, using repeated web-based questionnaires, combined with live interim group discussions was conducted by 33 experts within the field, from Europe, North America, and Asia. DGCE was divided into early DGCE if present within 14 days of surgery and late if present later than 14 days after surgery. The final criteria for early DGCE, accepted by 25 of 27 (93%) experts, were as follows: >500 mL diurnal nasogastric tube output measured on the morning of postoperative day 5 or later or >100% increased gastric tube width on frontal chest x-ray projection together with the presence of an air-fluid level. The final criteria for late DGCE accepted by 89% of the experts were as follows: the patient should have 'quite a bit' or 'very much' of at least two of the following symptoms; early satiety/fullness, vomiting, nausea, regurgitation or inability to meet caloric need by oral intake and delayed contrast passage on upper gastrointestinal water-soluble contrast radiogram or on timed barium swallow. A symptom grading tool for late DGCE was constructed grading each symptom as: 'not at all', 'a little', 'quite a bit', or 'very much', generating 0, 1, 2, or 3 points, respectively. For the five symptoms retained in the diagnostic criteria for late DGCE, the minimum score would be 0, and the maximum score would be 15. The final symptom grading tool for late DGCE was accepted by 27 of 31 (87%) experts. For the first time, diagnostic criteria for early and late DGCE and a symptom grading tool for late DGCE are available, based on an international expert consensus process
Prostaglandin I2 Signaling Drives Th17 Differentiation and Exacerbates Experimental Autoimmune Encephalomyelitis
BACKGROUND: Prostaglandin I(2) (PGI(2)), a lipid mediator currently used in treatment of human disease, is a critical regulator of adaptive immune responses. Although PGI(2) signaling suppressed Th1 and Th2 immune responses, the role of PGI(2) in Th17 differentiation is not known. METHODOLOGY/PRINCIPAL FINDINGS: In mouse CD4(+)CD62L(+) naïve T cell culture, the PGI(2) analogs iloprost and cicaprost increased IL-17A and IL-22 protein production and Th17 differentiation in vitro. This effect was augmented by IL-23 and was dependent on PGI(2) receptor IP signaling. In mouse bone marrow-derived CD11c(+) dendritic cells (BMDCs), PGI(2) analogs increased the ratio of IL-23/IL-12, which is correlated with increased ability of BMDCs to stimulate naïve T cells for IL-17A production. Moreover, IP knockout mice had delayed onset of a Th17-associated neurological disease, experimental autoimmune encephalomyelitis (EAE), and reduced infiltration of IL-17A-expressing mononuclear cells in the spinal cords compared to wild type mice. These results suggest that PGI(2) promotes in vivo Th17 responses. CONCLUSION: The preferential stimulation of Th17 differentiation by IP signaling may have important clinical implications as PGI(2) and its analogs are commonly used to treat human pulmonary hypertension
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