Home About us Contact
|
Home About us Contact | ||
|
|
||
Better Explanation (good + explanation)
Selected AbstractsGender and alcohol consumption: patterns from the multinational GENACIS projectADDICTION, Issue 9 2009Richard W. Wilsnack ABSTRACT Aims To evaluate multinational patterns of gender- and age-specific alcohol consumption. Design and participants Large general-population surveys of men's and women's drinking behavior (n's > 900) in 35 countries in 1997,2007 used a standardized questionnaire (25 countries) or measures comparable to those in the standardized questionnaire. Measurements Data from men and women in three age groups (18,34, 35,49, 50,65) showed the prevalence of drinkers, former drinkers, and lifetime abstainers; and the prevalence of high-frequency, high-volume, and heavy episodic drinking among current drinkers. Analyses examined gender ratios for prevalence rates and the direction of changes in prevalence rates across age groups. Findings Drinking per se and high-volume drinking were consistently more prevalent among men than among women, but lifetime abstention from alcohol was consistently more prevalent among women. Among respondents who had ever been drinkers, women in all age groups were consistently more likely to have stopped drinking than men were. Among drinkers, the prevalence of high-frequency drinking was consistently greatest in the oldest age group, particularly among men. Unexpectedly, the prevalence of drinking per se did not decline consistently with increasing age, and declines in high-volume and heavy episodic drinking with increasing age were more typical in Europe and English-speaking countries. Conclusions As expected, men still exceed women in drinking and high-volume drinking, although gender ratios vary. Better explanations are needed for why more women than men quit drinking, and why aging does not consistently reduce drinking and heavy drinking outside Europe and English-speaking countries. [source] ,Whatever is, is right'?ECONOMIC HISTORY REVIEW, Issue 4 2007Economic institutions in pre-industrial Europe Institutions,the structures of rules and norms governing economic transactions,are widely assigned a central role in economic development. Yet economic history is still dominated by the belief that institutions arise and survive because they are economically efficient. This article shows that alternative explanations of institutions, particularly those incorporating distributional effects, are consistent with economic theory and supported by empirical findings. Distributional conflicts provide a better explanation than efficiency for the core economic institutions of pre-industrial Europe: serfdom, the community, the craft guild, and the merchant guild. The article concludes by proposing four desiderata for any economic theory of institutions. [source] Activist Macroeconomic Policy, Election Effects and the Formation of Expectations: Evidence from OECD EconomiesECONOMICS & POLITICS, Issue 2 2000David Kiefer We examine the explanatory power of a political,business cycle theory in which governments practice short-run policy to lessen the impact of exogenous shocks. Governments have ideological objectives with respect to macroeconomic performance, but are constrained by an augmented Phillips curve. The most prominent version, the rational partisan model, incorporates forward-looking expectations. This model can be compared to a competing model based on backward-looking expectations. Alesina and Roubini's recent advocacy of the rational model uses OECD data. Our reconsideration of the same data, updated to 1995, suggests that the adaptive expectations version offers a better explanation than the rational one. [source] Spondylolysis in a pre-contact San Francisco Bay population: behavioural and anatomical sex differencesINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2009E. Weiss Abstract Spondylolysis refers to a separation of the spinal body from the arch. Researchers have documented that these fractures occur due to stresses related to activities involving the lower limb and back. Spondylolysis in sacral and lumbar vertebrae of 146 (66 males, 66 females, 14 indeterminates) California Amerinds were examined to determine whether sex differences were present. Sacral anatomy (i.e. sacralisation and lumbarisation, sacral base angles, and superior facet morphology) was analysed in relation to spondylolysis and sex, to explore whether sex differences could be better explained through activity patterns or anatomical variation. Spondylolysis afflicted 24 individuals (16.4%). Males had more than twice the rate of spondylolysis than did females (26% and 11%, respectively). Activity patterns, such as thrusting and throwing shafted obsidian points, could explain the sex differences. Males were most frequently buried with obsidian point artefacts, whereas females were buried with mortar and pestles. For sacral anatomy, only males had lumbarisation, and all other anatomical variation had no significant sex differences. Lumbarisation related to spondylolysis in males. In this study, sacral anatomical variation could not fully account for sex differences in spondylolysis; activity patterns provided a better explanation. Nonetheless, anatomical variation may predispose males to spondylolysis, or spondylolysis may affect sacral anatomy. Copyright © 2008 John Wiley & Sons, Ltd. [source] Prospect Theory and the Cuban Missile CrisisINTERNATIONAL STUDIES QUARTERLY, Issue 2 2001Mark L. Haas This article tests the predictions of expected-utility and prospect theories against the most important dimensions of the Cuban missile crisis. Largely through use of the most recently released information on the crisis from the American and Soviet governments, I attempt to ascertain the anticipated benefits, costs, and probabilities of success associated with each of the major policy choices that the key leaders in both superpowers perceived before each of the major decisions throughout the crisis was made. Using this information and the logic of extensive-form game-theoretic models of choice, I construct a baseline for expected-utility theory that helps us to understand when prospect or expected-utility theory provides the better explanation for a particular decision. Prospect theory predicts that when individuals perceive themselves to be experiencing losses at the time they make a decision, and when their probability estimates associated with their principal policy options are in the moderate to high range, they will tend to make excessively risky, non,value maximizing choices. I find that the evidence for the Cuban missile crisis supports this prediction for the most important decisions made by both Khrushchev and Kennedy. [source] Mechanisms of functional response and resource exploitation in browsing roe deerJOURNAL OF ANIMAL ECOLOGY, Issue 5 2002Andrew W. Illius Summary 1The functional responses of roe deer were examined using 11 plant species. A technique to discriminate between encounter- and handling-limited processes was used, and it can be concluded that the functional response applicable to patch browsing by roe deer is governed not by the rate of encounter but by the rate of oral processing. 2The large differences between plant species were due to variations in both parameters of the functional response: h , the time lost in biting, and Rmax , the maximum processing rate. Removing the thorns from three of the species affected these parameters differently, according to the size and density of thorns. 3Animals took larger bites from larger patches (branches), and bite mass declined as patch exploitation progressed, implying that animals were selecting the larger items to eat first. It was demonstrated experimentally that depletion of the larger bites does occur first, and it was concluded that prey selection is an important component of herbivore foraging behaviour. 4The gain curves for deer feeding on the different plant species are calculated as being virtually linear. Patch depression did not, in general, occur because increasing bite rate compensated for declining bite mass. Our mechanistic approach is contrasted with other approaches to describing the gain curve in the literature. 5A priori and empirical grounds are presented for rejecting the hypothesis that resource exploitation by browsing mammals is governed by optimal patch use. Diet optimization, involving a trade-off between diet quality and quantity, offers a better explanation of herbivore foraging behaviour. [source] Inaccurate endoscopy: a better explanation for placebo-associated endoscopic ulcersALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2009D. Y. Graham No abstract is available for this article. [source] Inaccurate endoscopy: a better explanation for placebo-associated endoscopic ulcers: authors' replyALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2009Y. Yuan No abstract is available for this article. [source] How stupid not to have thought of that: post-copulatory sexual selectionJOURNAL OF ZOOLOGY, Issue 2 2010T. R. Birkhead Abstract Science progresses through ideas or hypotheses; novel ways of viewing the world. If those ideas survive testing, then they are considered ,the truth', or more crucially, truth-for-now, for the essence of science is that if a new idea provides a better explanation of the way the world is, the truth changes. Darwin's idea of evolution by natural selection, published as the Origin in 1859, replaced the earlier truth of physico- or natural-theology introduced by John Ray in 1691. Despite resistance by the church, Darwin's truth gained widespread acceptance, in part due to the efforts of T. H. Huxley, who on reading the Origin said ,How extremely stupid not to have thought of that!' Despite natural selection's enormous explanatory power, there were certain phenomena it apparently could not explain, including female promiscuity. It was only in the 1960s when natural selection was viewed as operating explicitly on individuals (rather than populations or groups), that this changed. Rather than being a cooperative venture between the sexes, sexual reproduction was now viewed in terms of conflicts of interests, and in so doing provided an explanation for female promiscuity (albeit in a male-biased sort of way). Until this point, sexual selection had been concerned exclusively with mate acquisition. With an evolutionary perspective focussing on individuals, it was recognized that sexual selection might continue after insemination, and that rather than competing for partners, males compete for fertilizations. Later it was acknowledged that females, through cryptic processes can also influence the outcome of sperm competition. Today, post-copulatory sexual selection provides explanations for many previously bewildering reproductive traits, including the extraordinary diversity in male and female genitalia, the design of spermatozoa and ova, of seminal fluid and of copulation behaviour itself [source] FREEDOM OF OCCUPATIONAL CHOICERATIO, Issue 4 2008Michael Otsuka Cohen endorses the coercive taxation of the talented at a progressive rate for the sake of realizing equality. By contrast, he denies that it is legitimate for the state to engage in the ,Stalinist forcing' of people into one or another line of work in order to bring about a more egalitarian society. He rejects such occupational conscription on grounds of the invasiveness of the gathering and acting upon information regarding people's preferences for different types of work that would be required to implement such a policy. More precisely, Cohen maintains that the presence versus the absence of such intrusion explains why such Stalinist forcing of the talented is unacceptable whereas the progressive taxation of their income is legitimate. I argue that Cohen's appeal to invasiveness does not adequately capture the moral repugnance of the state's conscripting people into work at a given occupation. I propose that a right to self-ownership, and that which explains such a right, provides a better explanation than Cohen's of why Stalinist forcing is objectionable, whereas progressive taxation is not.1 [source] Warfarin resistance in a French strain of ratsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 6 2006Romain Lasseur Abstract A warfarin-resistant strain and a warfarin-susceptible strain of wild rats (Rattus norvegicus) maintained in enclosures of the National Veterinary School of Lyon (France) were studied to determine the mechanism of the resistance to anticoagulant rodenticides. A low vitamin K epoxide reductase (VKOR) activity has been reported for many resistant rat strains. As recently suggested, mutations in the vitamin K epoxide reductase subunit 1 (VKORC1) gene are the genetic basis of anticoagulant resistance in wild populations of rats from various locations in Europe. Here we report, for our strain, one of the seven described mutations (Tyr139Phe) for VKORC1 in rats. In addition, a low expression of mRNA encoding VKORC1 gene is observed in resistant rats, which could explain their low VKOR activity. We calculated kinetic parameters of VKOR in the warfarin-resistant and warfarin-susceptible rats. The Vmax and the Km of the VKOR obtained in resistant rats were lowered by 57 and 77%, respectively, compared to those obtained in susceptible rats. As a consequence, the enzymatic efficiency (Vm/Km) of the VKOR was similar between resistant and susceptible rats. This result could be a good explanation to the observation that no clinical signs of vitamin K deficiency was observed in the warfarin-resistant strain, while a low VKOR activity was found. VKOR activity in warfarin-resistant rats was poorly inhibited by warfarin (Ki for warfarin is 29 ,M and 0.72 ,M for resistant and susceptible rats, respectively). © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:379-385, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20104 [source] Structural and functional role of water molecules in bovine pancreatic phospholipase A2: a data-mining approachACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2009Shankar Prasad Kanaujia The water molecules in 25 (21 high-resolution and four atomic resolution) crystal structures of bovine pancreatic phospholipase A2 have been analyzed in order to identify the invariant water molecules and their possible roles. A total of 24 water molecules have been identified that are invariant in all 25 crystal structures examined. These include the catalytic water molecule, which is directly involved in the enzyme mechanism, and the conserved structural water molecule, which stabilizes the extended hydrogen-bonding network of the active site. Furthermore, many other water molecules stabilize the structure, whilst a few have been found to maintain the active-site geometry and provide coordination to the functionally important calcium ion. The invariant water molecules have been carefully examined and their possible roles in the structure and/or function are discussed. Molecular-dynamics studies of all 25 crystal structures have also been carried out and the results provide a good explanation of and support the findings obtained from the crystal structures. [source] Structures and molecular-dynamics studies of three active-site mutants of bovine pancreatic phospholipase A2ACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2008Shankar Prasad Kanaujia Phospholipase A2 hydrolyzes phospholipids at the sn -2 position to cleave the fatty-acid ester bond of l -glycerophospholipids. The catalytic dyad (Asp99 and His48) along with a nucleophilic water molecule is responsible for enzyme hydrolysis. Furthermore, the residue Asp49 in the calcium-binding loop is essential for controlling the binding of the calcium ion and the catalytic action of phospholipase A2. To elucidate the structural role of His48 and Asp49, the crystal structures of three active-site single mutants H48N, D49N and D49K have been determined at 1.9,Å resolution. Although the catalytically important calcium ion is present in the H48N mutant, the crystal structure shows that proton transfer is not possible from the catalytic water to the mutated residue. In the case of the Asp49 mutants, no calcium ion was found in the active site. However, the tertiary structures of the three active-site mutants are similar to that of the trigonal recombinant enzyme. Molecular-dynamics simulation studies provide a good explanation for the crystallographic results. [source] A critical appraisal of lithium's efficacy and effectiveness: the last 60 yearsBIPOLAR DISORDERS, Issue 2009Paul Grof The history that depicts the evaluation of lithium's efficacy presents an interesting contrast: on the one hand, conviction that, of all psychotropic drugs, lithium has the best demonstrated efficacy; on the other hand, repeated attempts to question it. Those contesting lithium's stabilizing abilities have argued from several angles, for example that the proof was methodologically incorrect or insufficient, that the number of responders is small, or that the response is poor in practice and does not last. But there is a good explanation for this paradox. While the early challenges to lithium's value in recurrent mood disorders reflected mainly that psychiatry had not yet developed a methodology suitable for testing long-term efficacy, more recent questioning has resulted mostly from retesting its efficacy and effectiveness in a substantially broadened bipolar spectrum, outside the classical diagnosis. Lithium, however, continues to stabilize very well the patients suffering from typical bipolar disorder,the condition for which its efficacy was originally demonstrated. More recently, lithium has also proven to dramatically reduce suicidal behavior and mortality and to augment markedly the efficacy of antidepressants in unresponsive patients. [source] | |||||||||||||||||||