1,721,164 research outputs found
Harm reduction for addictive consumption: When does it improve health and when does it backfire?
No full text: Some harm reduction strategies encourage individuals to switch from a harmful addictive good to a less harmful addictive good; examples include e-cigarettes (substitutes for combustible cigarettes) and methadone and buprenorphine (substitutes for opioids). These have proven to be controversial. Advocates argue that people struggling with addiction benefit because they can switch to a less harmful substance, but opponents argue that this could encourage abstainers to begin using the harm-reduction method or even, eventually, the original addictive good. This paper builds on theories of addiction to model the introduction of a harm reduction method, and demonstrates the conditions under which each side is correct
Njoerdichthys dyckerhoffi gen. et sp. nov. (Pycnodontiformes, lower Turonian) northward migration caused by the Cretaceous Thermal Maximum
No full textThe stem group teleost Pachycormus (Pachycormiformes:Pachycormidae) from the Upper Lias (Lower Jurassic) of Strawberry Bank, UK
Full text linkThree-dimensionally preserved specimens of the pachycormiform neopterygian Pachycormus from the Lower Jurassic (Upper Lias) of Strawberry Bank, Ilminster, UK, are described for the first time, and we present new and detailed morphological descriptions of the skull, trunk and fins of these specimens. The cranial material is characteristic of Pachycormus macropterus, with its operculum being twice as long as it is deep and the ventral angle lying towards the posterior half of the bone, and the preorbital portion occupying up to one-third of the skull. The description of the caudal fin conflicts with previous descriptions of caudal fins assumed to belong to Pachycormus. This raises the question of whether the other caudal fins belong to different species of Pachycormus, or whether it could be a case of intraspecific variability and is in conflict with morphometric data suggesting a monospecific status for Pachycormus. Recent phylogenetic analysis indicates that Pachycormus is sister taxon to Ohmdenia, which is an intermediate form between Pachycormus and the later giant suspension-feeding pachycormids. An alternative phylogenetic analysis reveals Pachycormus to be among the most basal pachycormiforms due to its incorporation of characters present in both hyper-carnivorous and suspension-feeding clades. We suggest future research on these specimens such as CT scanning of the skull may offer vital data regarding pachycormiform morphology and actinopterygian evolution, particularly the sister group relationship of pachycormiforms to the successful teleost fishes. In the future it may be important to focus on caudal fin characters of articulated specimens to identify possible cryptic species diversities within Pachycormus and also other members of Pachycormiformes.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
The Demand for Cigarettes as Derived from the Demand for Weight Control: A theoretical and empirical investigation
No full textThis paper offers an economic model of smoking and body weight and provides new empirical evidence on the extent to which the demand for cigarettes is derived from the demand for weight loss. In the model, smoking causes weight loss in addition to having direct utility benefits and direct health consequences. It predicts that some individuals smoke for weight loss and that the practice is more common among those who consider themselves overweight and those who experience greater disutility from excess weight.
We test these hypotheses using nationally representative data in which adolescents are directly asked whether they smoke to control their weight. We find that, among teenagers who smoke frequently, 46% of girls and 30% of boys are smoking in part to control their weight. As predicted by the model, this practice is significantly more common among those who describe themselves as too fat and among groups that tend to experience greater disutility from obesity.
We conclude by discussing the implications of these findings for tax policy; specifically, the demand for cigarettes is less
price elastic among those who smoke for weight loss, all else being equal. Public health efforts to reduce smoking initiation and encourage cessation may wish to design campaigns to alter the derived nature of cigarette demand, especially among adolescent girls
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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