1,695 research outputs found
Understanding Adolescent Intentions to Smoke: An Examination of Relationships Among Social Influence, Prior Trial Behavior, and Antitobacco Campaign Advertising
Telephone interviews were conducted with more than 900 adolescents aged 12 to 18 as part of a multimillion dollar, statewide, antitobacco advertising campaign. The interviews addressed two primary questions: (1) Do counter-advertising campaign attitudes directly affect antismoking beliefs and intent in a manner similar to those of conventional advertisements? and (2) Can advertising campaign attitudes have a stronger effect on beliefs and intent for adolescents with prior smoking behavior and for adolescents exposed to social influence (i.e., friends, siblings, or adult smoker in the home)? The authors\u27 findings show that advertising campaign attitudes, prior trial behavior, and social influence all directly affect antismoking beliefs and that advertising campaign attitudes interact with prior trial behavior to strengthen antismoking beliefs. The results indicate that attitudes related to the campaign, prior trial behavior, and social influence directly influence intent, and advertising campaign attitudes interact with social influence and prior trial behavior to attenuate adolescent intent to smoke. In addition, the effect of advertising campaign attitudes in attenuating social influence and prior trial behavior effects on adolescent intent to smoke persists even when the authors account for strongly held beliefs about smoking. The authors discuss implications for countermarketing communications and the design and understanding of future antismoking campaigns
Bioeconomics and biodiversity in harvested metacommunities : a patch-occupancy approach
© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecosphere 6, no. 11 (2015): 1-18, doi:10.1890/ES14-00503.1.We develop a coupled economic-metacommunity model to investigate the trade-off between diversity and profit for multispecies systems. The model keeps track of the presence or absence of species in habitat patches. With this approach, it becomes (relatively) simple to include more species than can typically be included in models that track species population density. We use this patch-occupancy framework to understand how profit and biodiversity are impacted by (1) community assembly, (2) pricing structures that value species equally or unequally, and (3) the implementation of marine reserves. We find that when local communities assemble slowly as a result of facilitative colonization, there are lower profits and optimal harvest rates, but the trade-off with diversity may be either large or small. The trade-off is diminished if later colonizing species are more highly valued than early colonizers. When the cost of harvesting is low, maximizing profits tends to sharply reduce biodiversity and maximizing diversity entails a large harvesting opportunity cost. In the models we analyze, marine reserves are never economically optimal for a profit-maximizing owner. However, management using marine reserves may provide low-cost biodiversity protection if the community is over-harvested.This research was supported by The Seaver Institute and the National Science Foundation (OCE-1031256) through grants awarded to J. B. Kellner and M. G. Neubert. E. A. Moberg was funded by NSF GRFP number 1122374 and MIT's Ida Green Fellowship
A precise determination of chlorinity of sea water using the Ag-AgCl indicator electrode
A knowledge of the relative currents of the oceans depends to a large extent upon a knowledge of the distribution of mass. Measurements of temperature and cblorinity are made to furnish the necessary data for the computations of the density
Evaluation of simulated responses to climate forcings: a flexible statistical framework using confirmatory factor analysis and structural equation modelling – Part 2: Numerical experiment
The performance of a new statistical framework, developed for
the evaluation of simulated temperature responses to climate forcings against
temperature reconstructions derived from climate proxy data for the last millennium, is evaluated
in a so-called pseudo-proxy experiment, where the true unobservable temperature is replaced
with output data from a selected simulation with a climate model. Being an extension of the statistical
model used in many detection and attribution (D&A) studies,
the framework under study involves two main types of statistical models, each of which is based
on the concept of latent (unobservable) variables: confirmatory factor analysis (CFA) models
and structural equation modelling (SEM) models.
Within the present pseudo-proxy experiment, each statistical model was fitted
to seven continental-scale regional data sets. In addition, their performance for each defined
region was compared to the performance of the corresponding statistical model used in D&A studies. The results of
this experiment indicated that the SEM specification is the most appropriate one for describing
the underlying latent structure of the simulated temperature data in question.
The conclusions of the experiment have been confirmed in a cross-validation study, presuming
the availability of several simulation data sets within each studied region. Since the experiment is
performed only for zero noise level in the pseudo-proxy data, all statistical models, chosen as final
regional models, await further investigation to thoroughly test their performance for realistic levels of
added noise, similar to what is found in real proxy data for past temperature variations.</p
On the bioeconomics of marine reserves when dispersal evolves
Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Natural Resource Modeling 28 (2015): 456-474, doi:10.1111/nrm.12075.Marine reserves are an increasingly used and potentially contentious tool in fisheries management. Depending upon the way that individuals move, no-take marine reserves can be necessary for maximizing equilibrium rent in some simple mathematical models. The implementation of no-take marine reserves often generates a redistribution of fishing effort in space. This redistribution of effort, in turn, produces sharp spatial gradients in mortality rates for the targeted stock. Using a two-patch model, we show that the existence of such gradients is a sufficient condition for the evolution of an evolutionarily stable conditional dispersal strategy. Thus, the dispersal strategy of the fish depends upon the harvesting strategy of the manager and vice versa. We find that an evolutionarily stable optimal harvesting strategy (ESOHS)—one which maximizes equilibrium rent given that fish disperse in an evolutionarily stable manner– - never includes a no-take marine reserve. This strategy is economically unstable in the short run because a manager can generate more rent by disregarding the possibility of dispersal evolution. Simulations of a stochastic evolutionary process suggest that such a short-run, myopic strategy performs poorly compared to the ESOHS over the long run, however, as it generates rent that is lower on average and higher in variability.This material is based upon work supported by funding from: The
Woods Hole Oceanographic Institution's Investment in Science Fund to MGN; The Recruitment
Program of Global Experts to YL; The University of Tennessee Center for Business and Economics
Research to SL; and the U.S. National Science Foundation (NSF) through grants OCE-1031256,
DEB-1257545, and DEB-1145017 to MGN, CNH-0707961 to GEH, DMS-1411476 to YL; and NSF
Graduate Research Fellowships under Grant No. 1122374 to EAM and ES
Evaluation of simulated responses to climate forcings: a flexible statistical framework using confirmatory factor analysis and structural equation modelling – Part 1: Theory
Evaluation of climate model simulations is a crucial task in climate research. Here, a new
statistical framework is proposed for evaluation of simulated temperature responses
to climate forcings against temperature reconstructions derived from climate proxy data for
the last millennium. The framework includes two types of statistical models, each of which is
based on the concept of latent (unobservable)
variables: confirmatory factor analysis (CFA) models and structural equation modelling
(SEM) models. Each statistical model presented is developed for use with data from a single region,
which can be of any size. The ideas behind the framework arose partly from a statistical model
used in many detection and attribution (D&A) studies.
Focusing on climatological characteristics of
five specific forcings of natural and anthropogenic origin, the present work theoretically
motivates an extension of the statistical model used in D&A studies to CFA and SEM models,
which allow, for example, for non-climatic noise in observational data without assuming
the additivity of the forcing effects.
The application of the ideas of CFA is exemplified in a small numerical study, whose aim was
to check the assumptions typically placed on ensembles
of climate model simulations when constructing mean sequences. The result of this study indicated
that some ensembles for some regions may not satisfy the assumptions in question.</p
Development of the Variable Dexterity Test: construction, reliability and validity
Background/Aims: This article introduces a dexterity test designed to assess individual types of
dexterity used to carry out activities of daily living (ADL). The Variable Dexterity Test (VDT) was
developed as part of a wider study, the broader aim being to fully understand dexterity and its effect
on human-product interaction during ADL. This was done with a view to improve occupational therapy
methods when assessing dexterity and general hand function.
Methods: The control group consisted of 24 healthy participants. Estimates of reliability and validity
were evaluated in this pilot study. Inter-rater and test-retest reliability were assessed using a one-way
ANOVA. The validity of the test was estimated by correlating participants’ VDT scores with their
proficiency to complete four ADL task actions and a standardised dexterity test (Purdue Pegboard Test).
Results: The test produced consistent results among the control group with both a single assessor
(test‑retest reliability) and multiple assessors (inter‑rater reliability). High correlations between
participants’ VDT scores and proficiency to perform ADL were found for most of the subtests. There
was also a high correlation between participants’ scores from the Purdue Pegboard Test and the VDT.
Conclusions: The VDT proved to be a flexible, reliable and valid tool that assesses dexterity based on
ability to carry out ADL. Validity and reliability estimates show encouraging values, which recognises
that the VDT can be used as an accurate method to assess more than one type of dexterity.</p
Impact of Birthing Room Design on Maternal Childbirth Experience: Results From the Room4Birth Randomized Trial
Objective: To study the effect of the birthing room design on nulliparous women’s childbirth experience up to 1 year after birth. Background: Although it is known that the birth environment can support or hinder birth processes, the impact of the birthing room design on maternal childbirth experience over time is insufficiently studied. Methods: The Room4Birth randomized controlled trial was conducted at a labor ward in Sweden. Nulliparous women in active stage of spontaneous labor were randomized (n = 406) to either a regular birthing room (n = 202) or a new birthing room designed with more person-centered considerations (n = 204). Childbirth experiences were measured 2 hr, 3 months, and 12 months after birth by using a Visual Analogue Scale of Overall Childbirth Experience (VAS-OCE), the Fear of Birth Scale (FOBS), and the Childbirth Experience Questionnaire (CEQ2). Results: Women randomized to the new room had a more positive childbirth experience reported on the VAS-OCE 3 months (p =.002) and 12 months (p =.021) after birth compared to women randomized to a regular room. Women in the new room also scored higher in the total CEQ2 score (p =.039) and within the CEQ2 subdomain own capacity after 3 months (p =.028). The remaining CEQ2 domains and the FOBS scores did not differ between the groups. Conclusions: These findings show that a birthing room offering more possibilities to change features and functions in the room according to personal needs and requirements, positively affects the childbirth experience of nulliparous women 3 and 12 months after they have given birth
Effects of early experience on group behaviour in fish
Animals that undergo a habitat shift face a number of challenges as they move between habitats; for example, they may encounter new predator species and may be vulnerable as they adapt to their new surroundings. An ability to adapt quickly to the new environment is likely to influence post-transition survival, and an understanding of the development of this ability is important in species that we rear for conservation and reintroduction programmes. Juvenile cod, Gadus morhua, undergo a habitat shift during their development, and they are also a species where reintroduction work has been tried. Here, we describe an experiment that investigated the effects that rearing environment has on cod shoaling behaviour. Cod were tested just after they had undergone the transition from a pelagic to a more benthic existence. We found that cod reared in either an enriched or in a plain, standard hatchery environment differed in terms of their shoaling responses; the shoaling tendency of fish reared in enriched tanks varied between testing environments, but fish reared in plain environments responded in the same way across the testing conditions. We discuss the influence of early experience on the development of appropriate behavioural responses and the importance of this for captive-reared species that are released into the wild
Magnetic record associated with tree ring density: Possible climate proxy
A magnetic signature of tree rings was tested as a potential paleo-climatic indicator. We examined wood from sequoia tree, located in Mountain Home State Forest, California, whose tree ring record spans over the period 600 – 1700 A.D. We measured low and high-field magnetic susceptibility, the natural remanent magnetization (NRM), saturation isothermal remanent magnetization (SIRM), and stability against thermal and alternating field (AF) demagnetization. Magnetic investigation of the 200 mm long sequoia material suggests that magnetic efficiency of natural remanence may be a sensitive paleoclimate indicator because it is substantially higher (in average >1%) during the Medieval Warm Epoch (700–1300 A.D.) than during the Little Ice Age (1300–1850 A.D.) where it is <1%. Diamagnetic behavior has been noted to be prevalent in regions with higher tree ring density. The mineralogical nature of the remanence carrier was not directly detected but maghemite is suggested due to low coercivity and absence of Verwey transition. Tree ring density, along with the wood's magnetic remanence efficiency, records the Little Ice Age (LIA) well documented in Europe. Such a record suggests that the European LIA was a global phenomenon. Magnetic analysis of the thermal stability reveals the blocking temperatures near 200 degree C. This phenomenon suggests that the remanent component in this tree may be thermal in origin and was controlled by local thermal condition
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