4,345 research outputs found

    Discussion of Likelihood Inference for Models with Unobservables: Another View

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    Discussion of "Likelihood Inference for Models with Unobservables: Another View" by Youngjo Lee and John A. Nelder [arXiv:1010.0303]Comment: Published in at http://dx.doi.org/10.1214/09-STS277A the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Above- and belowground herbivory jointly impact defense and seed dispersal traits in Taraxacum officinale

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    Plants are able to cope with herbivores by inducing defensive traits or growth responses that allow them to reduce or avoid the impact of herbivores. Since above- and belowground herbivores differ substantially in life-history traits, for example feeding types, and their spatial distribution, it is likely that they induce different responses in plants. Moreover, strong interactive effects on defense and plant growth are expected when above- and belowground herbivores are jointly present. The strengths and directions of these responses have been scarcely addressed in the literature. Using Taraxacum officinale, the root-feeding nematode Meloidogyne hapla and the locust Schistocerca gregaria as a model species, we examined to what degree above- and belowground herbivory affect (1) plant growth responses, (2) the induction of plant defensive traits, that is, leaf trichomes, and (3) changes in dispersal-related seed traits and seed germination. We compared the performance of plants originating from different populations to address whether plant responses are conserved across putative different genotypes. Overall, aboveground herbivory resulted in increased plant biomass. Root herbivory had no effect on plant growth. Plants exposed to the two herbivores showed fewer leaf trichomes than plants challenged only by one herbivore and consequently experienced greater aboveground herbivory. In addition, herbivory had effects that reached beyond the individual plant by modifying seed morphology, producing seeds with longer pappus, and germination success

    Occasions, people and places for pork consumption in Europe. Empirical findings from the Q-Porkchains pan-European consumer survey

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    Objective: to describe the occasions when, the places where and people with whom respondents reported pork meat consumption. Design & Setting: Cross-sectional web based survey in Belgium, Denmark, Germany, Greece and Poland, January 2008, with quota samples on gender (male, female), age categories (20- 44y and 45-70y), and locality of residence (urban, rural with low pig production density and rural with high pig production density). Subjects: 2437 respondents (51% women, 49% men; mean age 41.4 y SD 13.1). Methods: Online computer based survey, including sociodemographic information, anthropometrics (weight, height), and further questions on frequency of pork consumption (30 common items, 17 country-specific items), the occasions (working day, any day, weekend, special occasions), the company (alone, with family, with friends, with others) and the place of actual consumption (at home, outside of home). Results are aggregated for the five European countries. Results: Tenderloin, mignonette, brochette together with pork shoulder ranked as the first choices for weekend and special occasions. The most out-of home consumed products are mixed gyros-pita meat, pork based brochette, pizza, small cuts, marinated meat, escalope, shoulder, tenderloin and mixed meat. The Greek country specific Sygglino, Tigania, and the Country-style sausage are amongst the main preferences for out of home consumption. At European level, most products are consumed at home and with the family. Meat products such as salami, ham, and similar products are amongst the first choices when eating alone. Semi-processed meat like brochettes, small cuts and marinated or ready to eat dishes as gyros-pitas and pizza are the main choice for eating in the company of friends. Conclusions: European respondents seem to make specific choices of food depending on to the occasions, the places and the company. This information highlights the potential orientation of consumers towards fresh meat for special occasions or weekends, and more processed and convenient products when alone or socializing. This information is also useful to address interventions aiming at the improvement of food related health in Europe.Occasions, Pork consumption, Europe, Q-Porkchains, Food Consumption/Nutrition/Food Safety,

    Setting policy priorities for front-of-pack health claims and symbols in the European Union : expert consensus built by using a Delphi method

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    Despite the fact that front-of-pack nutrition labels such as health claims and symbols have received growing attention in consumer behavior research, comprehensive conclusions could not yet be drawn to develop concrete policy actions, owing to the complexity of the subject and a constantly changing market environment. In this study, evidence-based policy recommendations and communication guidelines have been derived from the findings of the EU FP7 project CLYMBOL (Role of health-related CLaims and sYMBOLs in consumer behavior, Grant Agreement 311963), and have been evaluated and prioritized by European stakeholders using a three-round Delphi method. A moderate level of consensus was achieved and results suggest that policy priority should focus on ways to improve consumer motivation and interest in healthy eating. Consumers' interest in healthy eating could be increased by adopting appropriate communication strategies such as using innovative ways to communicate the importance of healthy eating, which may aim to change the possible negative association between healthiness and tastiness. The highest-rated finding was related to consumers' favorable attitude towards health claims with shorter and less complex messages and health symbols with a visible endorsement. Meanwhile, there was a clear consensus that health claims need to be scientifically substantiated and credible but phrased without using overly complex scientific wordings, in order to be meaningful for consumers. Furthermore, stakeholders from academia and industry believe that consumer awareness about existing health claims should be increased. The identified policy recommendations and communication guidelines stem from recent empirical evidence and provide useful insights that guide future policy development aligning consumer protection issues as well as public health and food marketing communication interests

    Consumer perceptions of beef healthiness: results from a qualitative study in four European countries

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    <p>Abstract</p> <p>Background</p> <p>Consumer perception of the healthiness of beef is an important determinant of beef consumption. However, little is known about how consumers perceive the healthiness of beef. The aim of this study is to shed light on the associations between beef and health.</p> <p>Methods</p> <p>Eight focus group discussions were conducted in four European countries (France, UK, Germany, Spain), each consisting of seven to nine participants. A content analysis was performed on the transcripts of these discussions.</p> <p>Results</p> <p>Although beef was generally perceived as healthful, focus group participants expected positive as well as negative effects of beef consumption on their health. Labelled, branded, fresh and lean beef were perceived as signalling healthful beef, in contrast with further processed and packaged beef. Consumers felt that their individual choices could make a difference with respect to the healthiness of beef consumed. Focus group participants were not in favour of improving beef healthiness during processing, but rather focussed on appropriate consumption behaviour and preparation methods.</p> <p>Conclusions</p> <p>The individual responsibility for health implies that consumers should be able to make correct judgements about how healthful their food is. However, the results of this study indicate that an accurate assessment of beef healthiness is not always straightforward. The presented results on consumer perceptions of beef healthiness provide insights into consumer decision making processes, which are important for the innovation and product differentiation in the European beef sector, as well as for public health policy decisions related to meat consumption in general and beef consumption in particular.</p

    Indoor air quality in Michigan schools

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72796/1/j.1600-0668.2006.00459.x.pd

    Distinguishing Plutonium Metal from Plutonium Oxide Using Fast Neutrons, Preliminary Experimental Results

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    Estimating body composition in adolescent sprint athletes : comparison of different methods in a 3 years longitudinal design

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    A recommended field method to assess body composition in adolescent sprint athletes is currently lacking. Existing methods developed for non-athletic adolescents were not longitudinally validated and do not take maturation status into account. This longitudinal study compared two field methods, i.e., a Bio Impedance Analysis (BIA) and a skinfold based equation, with underwater densitometry to track body fat percentage relative to years from age at peak height velocity in adolescent sprint athletes. In this study, adolescent sprint athletes (34 girls, 35 boys) were measured every 6 months during 3 years (age at start = 14.8 +/- 1.5yrs in girls and 14.7 +/- 1.9yrs in boys). Body fat percentage was estimated in 3 different ways: 1) using BIA with the TANITA TBF 410; 2) using a skinfold based equation; 3) using underwater densitometry which was considered as the reference method. Height for age since birth was used to estimate age at peak height velocity. Cross-sectional analyses were performed using repeated measures ANOVA and Pearson correlations between measurement methods at each occasion. Data were analyzed longitudinally using a multilevel cross-classified model with the PROC Mixed procedure. In boys, compared to underwater densitometry, the skinfold based formula revealed comparable values for body fatness during the study period whereas BIA showed a different pattern leading to an overestimation of body fatness starting from 4 years after age at peak height velocity. In girls, both the skinfold based formula and BIA overestimated body fatness across the whole range of years from peak height velocity. The skinfold based method appears to give an acceptable estimation of body composition during growth as compared to underwater densitometry in male adolescent sprinters. In girls, caution is warranted when interpreting estimations of body fatness by both BIA and a skinfold based formula since both methods tend to give an overestimation

    Correlated Prompt Fission Data in Transport Simulations

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    Detailed information on the fission process can be inferred from the observation, modeling and theoretical understanding of prompt fission neutron and Îł\gamma-ray~observables. Beyond simple average quantities, the study of distributions and correlations in prompt data, e.g., multiplicity-dependent neutron and \gray~spectra, angular distributions of the emitted particles, nn-nn, nn-Îł\gamma, and Îł\gamma-Îł\gamma~correlations, can place stringent constraints on fission models and parameters that would otherwise be free to be tuned separately to represent individual fission observables. The FREYA~and CGMF~codes have been developed to follow the sequential emissions of prompt neutrons and Îł\gamma-rays~from the initial excited fission fragments produced right after scission. Both codes implement Monte Carlo techniques to sample initial fission fragment configurations in mass, charge and kinetic energy and sample probabilities of neutron and Îł\gamma~emission at each stage of the decay. This approach naturally leads to using simple but powerful statistical techniques to infer distributions and correlations among many observables and model parameters. The comparison of model calculations with experimental data provides a rich arena for testing various nuclear physics models such as those related to the nuclear structure and level densities of neutron-rich nuclei, the Îł\gamma-ray~strength functions of dipole and quadrupole transitions, the mechanism for dividing the excitation energy between the two nascent fragments near scission, and the mechanisms behind the production of angular momentum in the fragments, etc. Beyond the obvious interest from a fundamental physics point of view, such studies are also important for addressing data needs in various nuclear applications. (See text for full abstract.)Comment: 39 pages, 57 figure files, published in Eur. Phys. J. A, reference added this versio
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