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Potential Explanations (potential + explanation)
Selected AbstractsAllegiance Effects in Assessment: Unresolved Questions, Potential Explanations, and Constructive RemediesCLINICAL PSYCHOLOGY: SCIENCE AND PRACTICE, Issue 4 2008Scott O. Lilienfeld The provocative results of Blair, Marcus, and Boccaccini (2008) suggest that the allegiance effect, previously suggested in psychotherapy outcome studies, may apply to studies of actuarial risk assessment. Despite this finding, the mechanisms of the effect, particularly in assessment research, are unknown and warrant further investigation. We discuss the file drawer effect, selective reporting, and "data massaging" as three potential explanations for allegiance effects in the assessment domain. Furthermore, we offer four suggestions for minimizing allegiance effects and their impact: routinely coding for allegiance in meta-analytic studies, operationalizing allegiance in multiple ways, encouraging collaborations among authors with differing allegiances, and creating study registries to track all dependent variables measured in studies. [source] Personality and absenteeism: a meta-analysis of integrity testsEUROPEAN JOURNAL OF PERSONALITY, Issue S1 2003Deniz S. Ones Until recently, research focus has been on a variety of demographic, attitudinal, and organizational variables in predicting and explaining absenteeism. If personality traits predict absenteeism, then it may be possible to use measures of these traits to identify and select job applicants and thereby reduce absenteeism rates. In this research, our goal was to examine whether integrity tests could be used to predict absenteeism. Meta-analysis was applied to studies of the validity of pre-employment integrity tests for predicting voluntary absenteeism. Twenty-eight studies based on a total sample of 13,972 were meta-analysed. The estimated mean predictive validity of personality-based integrity tests was 0.33. This operational validity generalized across various predictor scales, organizations, settings, and jobs (SD,,=,0.00). Overt integrity tests, however, showed much lower predictive validity for absenteeism and greater variability than personality-based tests (,,=,0.09; SD,,=,0.16). The results indicate that a personnel selection approach to reducing absenteeism in organizations may be a useful strategy, particularly if personality-based integrity tests are utilized. Potential explanations for differences between these results and those found for Big Five measures of personality are offered. Future research investigating models of absenteeism should incorporate the personality constructs assessed by integrity tests. Copyright © 2003 John Wiley & Sons, Ltd. [source] A geomorphic template for the analysis of lake districts applied to the Northern Highland Lake District, Wisconsin, U.S.A.FRESHWATER BIOLOGY, Issue 3 2000JoaN. L. Riera 1. We tested the degree to which a lake's landscape position constrains the expression of limnological features and imposes a characteristic spatial pattern in a glacial lake district, the Northern Highland Lake District in north-central Wisconsin. 2. We defined lake order as a metric to analyze the effect of landscape position on limnological features. Lake order, analogous to stream order, is based solely on geographical information and is simple to measure. 3. We examined the strength of the relationship between lake order and a set of 25 variables, which included measures of lake morphometry, water optical properties, major ions, nutrients, biology, and human settlement patterns. 4. Lake order explained a significant fraction of the variance of 21 of the 25 variables tested with ANOVA. The fraction of variance explained varied from 12% (maximum depth) to 56% (calcium concentration). The variables most strongly related to lake order were: measures of lake size and shape, concentrations of major ions (except sulfate) and silica, biological variables (chlorophyll concentration, crayfish abundance, and fish species richness), and human-use variables (density of cottages and resorts). Lake depth, water optical properties, and nutrient concentrations (other than silica) were poorly associated with lake order. 5. Potential explanations for a relationship with lake order differed among variables. In some cases, we could hypothesize a direct link. For example, major ion concentration is a function of groundwater input, which is directly related to lake order. We see these as a direct influence of the geomorphic template left by the retreat of the glacier that led to the formation of this lake district. 6. In other cases, a set of indirect links was hypothesized. For example, the effect of lake order on lake size, water chemistry, and lake connectivity may ultimately explain the relation between lake order and fish species richness. We interpret these relationships as the result of constraints imposed by the geomorphic template on lake development over the last 12 000 years. 7. By identifying relationships between lake characteristics and a measure of landscape position, and by identifying geomorphologic constraints on lake features and lake evolution, our analysis explains an important aspect of the spatial organization of a lake district. [source] The association between students' use of an electronic voting system and their learning outcomesJOURNAL OF COMPUTER ASSISTED LEARNING, Issue 4 2005G. E. Kennedy Abstract This paper reports on the use of an electronic voting system (EVS) in a first-year computing science subject. Previous investigations suggest that students' use of an EVS would be positively associated with their learning outcomes. However, no research has established this relationship empirically. This study sought to establish whether there was an association between students' use of an EVS over one semester and their performance in the subject's assessment tasks. The results from two stages of analysis are broadly consistent in showing a positive association between EVS usage and learning outcomes for students who are, relative to their class, more correct in their EVS responses. Potential explanations for this finding are discussed as well as modifications and future directions of this program of research. [source] Open Source Software: Private Provision of a Public GoodJOURNAL OF ECONOMICS & MANAGEMENT STRATEGY, Issue 4 2002Justin Pappas Johnson A simple model of open source software (as typified by the GNU-Linux operating system) is presented. Individual user-programmers decide whether to invest their own effort to develop a software enhancement that will become a public good if so developed. The effect of changing the population size of user-programmers is considered; finite and asymptotic results are given. Welfare results are presented. It is shown that whether development will increase when applications have a modular structure depends on whether the developer base exceeds a critical size. Potential explanations of several stylized facts are given, including why certain useful programs don't get written. [source] Testing for microevolution in body size in three blue tit populationsJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2004A. Charmantier Abstract Quantifying the genetic variation and selection acting on phenotypes is a prerequisite for understanding microevolutionary processes. Surprisingly, long-term comparisons across conspecific populations exposed to different environments are still lacking, hampering evolutionary studies of population differentiation in natural conditions. Here, we present analyses of additive genetic variation and selection using two body-size traits in three blue tit (Parus caeruleus) populations from distinct habitats. Chick tarsus length and body mass at fledging showed substantial levels of genetic variation in the three populations. Estimated heritabilities of body mass increased with habitat quality. The poorer habitats showed weak positive selection on tarsus length, and strong positive selection on body mass, but there was no significant selection on either trait in the good habitat. However, there was no evidence of any microevolutionary response to selection in any population during the study periods. Potential explanations for this absence of a response to selection are discussed, including the effects of spatial heterogeneity associated with gene flow between habitats. [source] Childhood sexual abuse and obesityOBESITY REVIEWS, Issue 3 2004T. B. Gustafson Summary The causes of the current obesity epidemic are multifactorial and include genetic, environmental, and individual factors. One potential risk factor may be the experience of childhood sexual abuse. Childhood sexual abuse is remarkably common and is thought to affect up to one-third of women and one-eighth of men. A history of childhood sexual abuse is associated with numerous psychological sequelae including depression, anxiety, substance abuse, somatization, and eating disorders. Relatively few studies have examined the relationship between childhood sexual abuse and adult obesity. These studies suggest at least a modest relationship between the two. Potential explanations for the relationship have focused on the role of disordered eating, particularly binge eating, as well as the possible ,adaptive function' of obesity in childhood sexual abuse survivors. Nevertheless, additional research on the relationship between childhood sexual abuse and obesity is clearly needed, not only to address the outstanding empirical issues but also to guide clinical care. [source] Effects of sugar feeding on carbohydrate and lipid metabolism in a parasitoid waspPHYSIOLOGICAL ENTOMOLOGY, Issue 1 2000D.A.W.N. M. Olson Summary Lifetime patterns of carbohydrate and lipid metabolism were compared in starved and sucrose-fed adults of the parasitoid Macrocentrus grandii (Goidanich) (Hymenoptera: Braconidae). As expected, sucrose-fed individuals lived longer than did starved individuals. Macrocentrus grandii males and females eclosed with levels of simple storage sugars (presumably primarily trehalose) and glycogen that were below maximum levels recorded from sucrose-fed parasitoids. Both of these nutrients dropped to very low levels in starved individuals within 4 days post-emergence and were maintained at high levels in sucrose-fed individuals throughout their lives. Lipid reserves at emergence represented the highest lipid levels for both sexes in the two diet treatments, with levels declining over the lifetimes of males and females from both diet treatments. Our results therefore suggest that dietary sucrose is used to synthesize trehalose and glycogen, but not lipids in M. grandii. Also, in contrast to the patterns observed for the simple sugars and glycogen, lipid levels in starved individuals did not drop below levels observed in sugar-fed individuals. The average number of mature eggs carried by females at emergence was 33 and increased to approximately 85 in sucrose-fed and 130 in starved females by the age of 5 d in the absence of hosts. The egg maturation rate was therefore higher in starved than in sugar-fed females. Potential explanations for this unexpected result are discussed. [source] The concept of positive health: a review and commentary on its application in oral health researchCOMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY, Issue 3 2006David Locker Abstract , Although the concept of positive health has been around for more than 60 years, acceptable measures of this construct have yet to emerge. Potential explanations are that there is no consensus on how it is to be defined and its ambiguous status with respect to medical and socioenvironmental models of health. In this paper we review definitions of positive health, the origins of these definitions, the way the concept of positive outcomes has been used in research on the outcomes of oral and orofacial conditions and assess whether the concept of positive health has any merit in terms of applied oral health research. This literature reveals many competing and imprecise definitions, many of which are similar to other constructs, such as well-being. Most are lacking empirical referents or indicators. In examining the literature on oral health we found five distinct, although overlapping, ways in which the concept of positive health has been framed: (i) positive health as the absence of negative health states; (ii) positive health as positively worded items; (iii) the positive outcomes of oral health; (iv) positive oral health as a set of psychological and social attributes, and (v) the positive outcomes of chronic conditions such as oro- and craniofacial differences. Each of these ways can be challenged on conceptual or methodological grounds. For example, the states that comprise the upper end of the negative,positive health continuum have not been defined and health states and determinants of health are often confused. Moreover, the meaning of responses to health status questionnaires and the interpretation of accounts of the illness experience is often unclear. Nevertheless, the notion of positive health, irrespective of its merits and public policy implications, provides a context for methodological and theoretical debate that can only serve to enrich theory and practice with respect to measures of health and quality of life and therapeutic interventions at the individual and population. [source] OBESITY AND NUTRIENT CONSUMPTION: A RATIONAL ADDICTION?CONTEMPORARY ECONOMIC POLICY, Issue 3 2007TIMOTHY J. RICHARDS Recent research shows that the dramatic rise in obesity in the United States is due more to the overconsumption of unhealthy foods than underactivity. This study tests for an addiction to food nutrients as a potential explanation for the apparent excessive consumption. A random coefficients (mixed) logit model is used to test a multivariate rational addiction model. The results reveal a particularly strong addiction to carbohydrates. The implication of this finding is that price-based policies, sin taxes, or produce subsidies that change the expected future costs and benefits of consuming carbohydrate-intensive foods may be effective in controlling excessive nutrient intake. (JEL D120, I120, C230) [source] Changes in Canadian heroin supply coinciding with the Australian heroin shortageADDICTION, Issue 5 2006Evan Wood ABSTRACT Aims Previous studies have largely attributed the Australian heroin shortage to increases in local law enforcement efforts. Because western Canada receives heroin from similar source nations, but has not measurably increased enforcement practices or funding levels, we sought to examine trends in Canadian heroin-related indices before and after the Australian heroin shortage, which began in approximately January 2001. Methods During periods before and after January 2001, we examined the number of fatal overdoses and ambulance responses to heroin-related overdoses that required the use of naloxone in British Columbia, Canada. As an overall marker of Canadian supply reduction, we also examined the quantity of heroin seized during this period. Lastly, we examined trends in daily heroin use among injection drug users enrolled in the Vancouver Injection Drug Users Study (VIDUS). Results There was a 35% reduction in overdose deaths, from an annual average of 297 deaths during the years 1998,2000 in comparison to an average of 192 deaths during 2001,03. Similarly, use of naloxone declined 45% in the period coinciding with the Australian heroin shortage. Interestingly, the weight of Canadian heroin seized declined 64% coinciding with the Australian heroin shortage, from an average of 184 kg during 1998,2000 to 67 kg on average during 2001,03. Among 1587 VIDUS participants, the period coinciding with the Australian heroin shortage was associated independently with reduced daily injection of heroin [adjusted odds ratio: 0.55 (95% CI: 0.50,0.61); P < 0.001]. Conclusions Massive decreases in three independent markers of heroin use have been observed in western Canada coinciding with the Australian heroin shortage, despite no increases in funding to Canadian enforcement efforts. Markedly reduced Canadian seizure activity also coincided with the Australian heroin shortage. These findings suggest that external global heroin supply forces deserve greater investigation and credence as a potential explanation for the Australian heroin shortage. [source] Brook trout, Salvelinus fontinalis, microhabitat selection and diet under low summer stream flowsFISHERIES MANAGEMENT & ECOLOGY, Issue 3 2006J. C. SOTIROPOULOS Abstract, This study investigated the effects of low summer discharge on habitat, prey use and prey availability for age 1 brook trout, Salvelinus fontinalis (Mitchill), in two small streams in Massachusetts, USA. Stream discharge declined substantially from June to August, with corresponding decreases in microhabitat depth and velocity; but fish habitat preferences were consistent throughout the summer, with fish selecting deep, low current velocity locations. Invertebrate drift rate, drift density and trout stomach fullness were significantly greater in June than August samples. Diets were dominated by aquatic-derived prey (chironomid larvae and adult blackflies) in June, but terrestrial invertebrates were the most frequent diet items in August. Consistent occupancy of low-velocity, deep microhabitats with low invertebrate flux rates indicated that, despite variation in habitat and prey conditions, trout adopted a habitat-use strategy of minimising risks and energy costs rather than maximising forage gain. This observation is consistent with, and provides a potential explanation for, the low summer growth rates of brook trout observed in small streams. [source] Plasma lipid concentrations after 1.5 years of exposure to nevirapine or efavirenz together with stavudine and lamivudineHIV MEDICINE, Issue 6 2006F Van Leth Objectives To assess long-term changes in lipids and lipoproteins concentrations associated with exposure to non-nucleoside reverse transcriptase inhibitors. Methods Long-term analysis of plasma lipid concentrations was performed in patients starting first-line antiretroviral therapy with stavudine (d4T) and lamivudine, and either nevirapine or efavirenz. Results Concentrations of total cholesterol, low-density lipoprotein cholesterol and triglycerides continued to increase, while high-density lipoprotein cholesterol showed a slight decrease compared with earlier reported increases after 48 weeks. Conclusions Changes in body fat distribution expected to occur with continued exposure to d4T could offer a potential explanation for these findings. [source] TESTING LONG-HORIZON PREDICTIVE ABILITY WITH HIGH PERSISTENCE, AND THE MEESE,ROGOFF PUZZLE*INTERNATIONAL ECONOMIC REVIEW, Issue 1 2005Barbara Rossi A well-known puzzle in international finance is that a random walk predicts exchange rates better than economic models. I offer a potential explanation. When exchange rates and fundamentals are highly persistent, long-horizon forecasts of economic models are biased by the estimation error. When this bias is big, a random walk will forecast better, even if the economic model is true. I propose a test for equal predictability in the presence of high persistence. It shows that the poor forecasting ability of economic models does not imply that the models are not good descriptions of the data. [source] The Determinants of Bank Credit in Industrialized Countries: Do Property Prices Matter?INTERNATIONAL FINANCE, Issue 2 2004Boris Hofmann In this study, we analyse the determinants of bank credit to the private non-financial sector in 16 industrialized countries based on a cointegrating VAR. Cointegration analysis suggests that property prices are an important determinant of the long-run borrowing capacity of the private sector, which needs to be taken into account to explain the long-run movements of bank lending. Impulse response analysis reveals that innovations to property prices also have a highly significant and persistent positive dynamic effect on bank lending. This result suggests that innovations to property prices may give rise to significant and persistent cycles in bank lending and are thus a potential explanation for the persistent financial cycles observed in the past. [source] The role of Steller sea lions in a large population decline of harbor sealsMARINE MAMMAL SCIENCE, Issue 4 2010Elizabeth A. Mathews Abstract We provide the first direct evidence that Steller sea lions will prey on harbor seals. Direct observations of predation on marine mammals at sea are rare, but when observed rates of predation are extrapolated, predation mortality may be found to be significant. From 1992 to 2002, harbor seals in Glacier Bay declined steeply, from 6,200 to 2,500 (,65%). After documenting that Steller sea lions were preying on seals in Glacier Bay, we investigated increased predation by sea lions as a potential explanation for the large decline. In five independent data sets spanning 21,25 yr and including 14,308 d of observations, 13 predation events were recorded. We conducted a fine-scale analysis for an intensively studied haul-out (Spider Island) and a broader analysis of all of Glacier Bay. At Spider Island, estimated predation by sea lions increased and could account for the entirety of annual pup production in 5 of 8 yr since 1995. The predation rate, however, was not proportional to the number of predators. Predation by Steller sea lions is a new source of mortality that contributed to the seal declines; however, life history modeling indicates that it is unlikely that sea lion predation is the sole factor responsible for the large declines. [source] RECONSIDERING THE INVESTMENT,PROFIT NEXUS IN FINANCE-LED ECONOMIES: AN ARDL-BASED APPROACHMETROECONOMICA, Issue 3 2008Till Van TreeckArticle first published online: 28 APR 200 ABSTRACT A Post-Keynesian growth model is developed, in which financial variables are explicitly taken into account. Variants of an investment function are estimated econometrically, applying the ARDL (auto-regressive distributed lag)-based approach proposed by Pesaran et al. (Journal of Applied Econometrics, 16 (3), pp. 289,326). The econometric results are discussed with respect to a remarkable phenomenon that can be observed for some important OECD countries since the early 1980s: accumulation has generally been declining while profit shares and rates have shown a tendency to rise. We concentrate on one potential explanation of this phenomenon, which is particularly relevant for the USA and relies on a high propensity to consume out of capital income. [source] Junk-food in marine ecosystemsOIKOS, Issue 7 2008Henrik Österblom The abundance and availability of food are critical determininants of reproductive success and population dynamics of marine top predators. However, recent work has indicated that the quality of the food may also be critically important for some marine predators. The ,junkfood hypothesis' was originally suggested as a potential explanation for a dramatic population decline of Stellers sea lions Eumetopias jubatus in the Gulf of Alaska. According to the hypothesis, a dietary switch to prey of low energy content led to detrimental effects on the population of sea lions. A number of observations indicate that the hypothesis is relevant for several population parameters. Recent work on piscivorous seabirds has provided substantial evidence indicating the relevance of this hypothesis in food webs in e.g. the North Pacific, the North Sea and the Baltic Sea. The emergence of ,junk-food' in these systems may be coupled to large scale changes in climatological and oceanographic forcing, although predation, fishing and competition provide additional plausible hypotheses. It may be possible to predict which kinds of animals will be particularly sensitive to food quality; these seem to be species with limited ability to carry food loads, with energetically-expensive foraging behaviour, and with digestive anatomy evolved to minimize mass at the cost of digestive efficiency. This review suggests that the junk-food hypothesis is a highly relevant factor in relation to sustaining ecosystem resilience, and is an important consideration in ecosystem management. Sustaining healthy populations of marine top-predators requires an understanding of the role of food quality, in addition to food abundance and availability. [source] Stripe fractionalization: the quantum spin nematic and the Abrikosov latticePHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003J. Zaanen The cover picture of physica status solidi (b), taken from the Editor's Choice of this issue, shows a scheme of construction of the spin nematic ordered state and the topological interaction between spatially disconnected gauge defects. The gauge symmetry is broken by applying an external field B. The theory described in the paper [1] offers a potential explanation for recent observations of magnetic field induced antiferromagnetism in La1.9Sr0.1CuO4. The first author, Jan Zaanen, is Professor of Physics at the Instituut-Lorentz in Leiden where he works on quantum field theory in condensed matter physics, concentrating on problems in high- TC superconductivity, quantum magnetism, quantum liquid crystals, doped Mott insulators, and strongly correlated electron systems. This paper is an invited presentation from the European Conference Physics of Magnetism (PM'02), held in Pozna,, Poland, 1,5 July 2002. The proceedings of this conference are published in two parts: in the present issue of phys. stat. sol. (b) and in phys. stat. sol. (a) 196, No. 1 (2003). [source] Stripe fractionalization: the quantum spin nematic and the Abrikosov latticePHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003J. Zaanen Abstract In part (I) of this two paper series on stripe fractionalization [J. Phys. IV (France) 12, Prg-245 (2002)], we argued that in principle the "domain wall-ness" of the stripe phase could persist in the spin and charge disordered superconductors, and we demonstrated how this physics is in one-to-one correspondence with Ising gauge theory. Here we focus on yet another type of order suggested by the gauge theory: the quantum spin nematic. Although it is not easy to measure this order directly, we argue that the superconducting vortices act as perturbations destroying the gauge symmetry locally. This turns out to give rise to a simple example of a gauge-theoretical phenomenon known as topological interaction. As a consequence, at any finite vortex density a globally ordered antiferromagnet emerges. This offers a potential explanation for recent observations in the underdoped 214 system. [source] NMR structure of the pseudo -receiver domain of CikAPROTEIN SCIENCE, Issue 3 2007Tiyu Gao Abstract The circadian input kinase (CikA) is a major element of the pathway that provides environmental information to the circadian clock of the cyanobacterium Synechococcus elongatus. CikA is a polypeptide of 754 residues and has three recognizable domains: GAF, histidine protein kinase, and receiver-like. This latter domain of CikA lacks the conserved phospho-accepting aspartyl residue of bona fide receiver domains and is thus a pseudo -receiver (PsR). Recently, it was shown that the PsR domain (1) attenuates the autokinase activity of CikA, (2) is necessary to localize CikA to the cell pole, and (3) is necessary for the destabilization of CikA in the presence of the quinone analog 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB). The solution structure of the PsR domain of CikA, CikAPsR, is presented here. A model of the interaction between the PsR domain and HPK portion of CikA provides a potential explanation for how the PsR domain attenuates the autokinase activity of CikA. Finally, a likely quinone-binding surface on CikAPsR is shown here. [source] Temporal and Spatial Distribution of the Cannabinoid Receptors (CB1, CB2) and Fatty Acid Amide Hydroxylase in the Rat OvaryTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 8 2010P. Bagavandoss Abstract Although the effects of ,9 -tetrahydrocannabinol (THC) on ovarian physiology have been known for many decades, its mechanism of action in the rat ovary remains poorly understood. The effects of THC and endocannabinoids on many cell types appear to be mediated through the G-protein-coupled CB1 and CB2 receptors. Evidence also suggests that the concentration of the endocannabinoid anandamide is regulated by cellular fatty acid amide hydrolase (FAAH). Therefore, we examined the rat ovary for the presence of CB1 and CB2 receptors and FAAH. The CB1 receptor was present in the ovarian surface epithelium (OSE), the granulosa cells of antral follicles, and the luteal cells of functional corpus luteum (CL). The granulosa cells of small preantral follicles, however, did not express the CB1 receptor. Western analysis also demonstrated the presence of a CB1 receptor. In both preantral and antral follicles, the CB2 receptor was detected only in the oocytes. In the functional CL, the CB2 receptor was detected in the luteal cells. FAAH was codistributed with CB2 receptor in both oocytes and luteal cells. FAAH was also present in the OSE, subepithelial cords of the tunica albuginea (TA) below the OSE, and in cells adjacent to developing preantral follicles. Western analysis also demonstrated the presence of FAAH in oocytes of both preantral and antral follicles. Our observations provide potential explanation for the effects of THC on steroidogenesis in the rat ovary observed by earlier investigators and a role for FAAH in the regulation of ovarian anandamide. Anat Rec 293:1425,1432, 2010. © 2010 Wiley-Liss, Inc. [source] An evaluation of PCR primer sets used for detection of Propionibacterium acnes in prostate tissue samplesTHE PROSTATE, Issue 14 2008Karen S. Sfanos Abstract BACKGROUND Multiple studies have now shown that Propionibacterium acnes can be cultured from post-prostatectomy derived prostate tissue samples. In contrast, both universal eubacterial 16S rDNA PCR and P. acnes -specific 16S rDNA PCR have failed to detect this organism at a frequency similar to that of bacterial culture. A potential explanation for this discrepancy, proposed by Cohen et al., involves mismatches in 16S rDNA primer sets used for bacterial detection. METHODS The sensitivity of both a previously published P. acnes -specific primer set containing a potential mismatch and a new primer set with no mismatches was determined. Both primer sets were used to interrogate two sets of DNA samples derived from post-prostatectomy prostate tissues that differed in the level of sterile precautions maintained during tissue collection. RESULTS The number of P. acnes positive samples was associated with the sterility of the sample collection process. In all instances, positive samples were determined to reflect low cell numbers (<10 CFU). CONCLUSIONS Although the results of previous studies have shown that P. acnes is not the only organism potentially present in the prostates of prostate cancer patients, mismatches in PCR primer sets may have also influenced the sensitivity of P. acnes detection. When using PCR in determining the presence of P. acnes in the human prostate, care should be taken to establish the potential influence of exogenous contamination and, due to the sensitivity of the assay, samples exposed to the urethra during the collection process (prostatic secretions, TURP specimens) should not be used. Prostate 68: 1492,1495, 2008. © 2008 Wiley-Liss, Inc. [source] Does pregnancy provide vaccine-like protection against rheumatoid arthritis?ARTHRITIS & RHEUMATISM, Issue 7 2010Katherine A. Guthrie Objective Previous studies have evaluated the correlation between rheumatoid arthritis (RA) risk and pregnancy history, with conflicting results. Fetal cells acquired during pregnancy provide a potential explanation for modulation of RA risk by pregnancy. The present study was undertaken to examine the effect of parity on RA risk. Methods We examined parity and RA risk using results from a population-based prospective study in Seattle, Washington and the surrounding area and compared women who were recently diagnosed as having RA (n = 310) with controls (n = 1,418). We also evaluated the distribution of parity in cases according to HLA genotype. Results We found a significant reduction of RA risk associated with parity (relative risk [RR] 0.61 [95% confidence interval 0.43,0.86], P = 0.005). RA risk reduction in parous women was strongest among those who were younger. Most striking was that RA risk reduction correlated with the time that had elapsed since the last time a woman had given birth. RA risk was lowest among women whose last birth occurred 1,5 years previously (RR 0.29), with risk reduction lessening progressively as the time since the last birth increased (for those 5,15 years since last birth, RR 0.51; for those >15 years, RR 0.76), compared with nulliparous women (P for trend = 0.007). No correlation was observed between RA risk and either age at the time a woman first gave birth or a woman's total number of births. Among cases with the highest genetic risk of RA (i.e., those with 2 copies of RA-associated HLA alleles), a significant underrepresentation of parous women versus nulliparous women was observed (P = 0.02). Conclusion In the present study, there was a significantly lower risk of RA in parous women that was strongly correlated with the time elapsed since a woman had last given birth. While the explanation for our findings is not known, HLA-disparate fetal microchimerism can persist many years after a birth and could confer temporary protection against RA. [source] Type II collagen levels correlate with mineralization by articular cartilage vesiclesARTHRITIS & RHEUMATISM, Issue 9 2009Brian Jubeck Objective Pathologic mineralization is common in osteoarthritic (OA) cartilage and may be mediated by extracellular organelles known as articular cartilage vesicles (ACVs). Paradoxically, ACVs isolated from OA human cartilage mineralize poorly in vitro compared with those isolated from normal porcine cartilage. We recently showed that collagens regulate ACV mineralization. We sought to determine differences between collagens and collagen receptors on human and porcine ACVs as a potential explanation of their different mineralization behaviors. Methods ACVs were enzymatically released from old and young human and porcine hyaline articular cartilage. Western blotting was used to determine the presence of types I, II, VI, and X collagen and various collagen receptors on ACVs. Type II collagen was quantified by enzyme-linked immunosorbent assay. Biomineralization was assessed by measuring the uptake of 45Ca by isolated ACVs in agarose gels and by ACVs in situ in freeze-thawed cartilage. Results As previously shown, isolated human ACVs mineralized poorly in response to ATP compared with porcine ACVs, but human and porcine ACVs mineralized similarly in situ in freeze-thawed cartilage. Type II collagen levels were 100-fold higher in isolated human ACVs than in porcine ACVs. Type II collagen in human ACVs was of high molecular weight. Transglutaminase-crosslinked type II collagen showed increased resistance to collagenase, suggesting a possible explanation for residual collagen on human ACVs. Expression of other collagens and collagen receptors was similar on human and porcine ACVs. Conclusion Higher levels of type II collagen in human ACV preparations, perhaps mediated by increased transglutaminase crosslinking, may contribute to the decreased mineralization observed in isolated human ACVs in vitro. [source] The Impact of Internal Auditor Compensation and Role on External Auditors' Planning Judgments and Decisions,CONTEMPORARY ACCOUNTING RESEARCH, Issue 2 2001F. Todd Dezoort Abstract This paper reports the results of an experiment that investigates how external audit planning is affected when internal auditors have incentives and the opportunity to bias their evaluations. Specifically, we draw on attribution theory to examine how internal auditor eligibility for incentive compensation and participation in consulting (i.e., two factors that provide incentives to bias audit evaluations) affect external audit planning. In addition, we examine the effects of incentive compensation and a consulting role across two routine internal audit tasks , an objective tests of controls task and a subjective inventory valuation task , to evaluate whether their effects are contingent upon task subjectivity (i.e., opportunity to bias audit evaluations). Seventy-six external auditors from four Big 5 public accounting firms participated in an experiment that manipulated internal auditor compensation (fixed salary versus incentive compensation), the type of work that the internal auditors routinely perform (primarily auditing versus primarily consulting), and audit task subjectivity (objective tests of controls versus subjective inventory valuation). Our results suggest that the nature of internal auditors' compensation and work affect audit planning recommendations differently. The opportunity to receive incentive compensation results in less reliance on internal auditors' work and greater budgeted audit hours, but only for the subjective task. Although a consulting role decreases perceived internal auditor objectivity, it has a limited effect on planning recommendations. Specifically, consulting has no effect on reliance, and leads to greater budgeted audit hours only when incentive compensation is available. We discuss potential explanations for the results as well as implications for audit research, practice, and regulation. [source] Elevational gradients, area and tropical island diversity: an example from the palms of New GuineaECOGRAPHY, Issue 3 2004Steven Bachman The factors causing spatial variation in species richness remain poorly known. In this study, factors affecting species richness of palms (Palmae/Arecaceae) were studied along the elevational gradient of New Guinea. Interpolated elevational ranges were calculated from a database of all known collections for 145 species in 32 genera. The amount of land area at different elevations greatly affects the species richness gradient. If assessed in equal-elevation bands species richness appears to decline monotonically, but when assessed in equal-area bands species richness shows a pronounced mid-elevation peak, due to the large proportion of lowlands in New Guinea. By randomising species ranges within the total elevational gradient for palms and accounting for area, we found the mid-elevation peak to be consistent with a mid-domain effect caused by the upper and lower limits to palm distribution. Our study illustrates the importance of accounting for area in macroecological studies of richness gradients and introduces a novel yet simple method for doing this through the use of equal-area bands. Together, the effect of area and the mid-domain effect explain the majority of variation in species richness of New Guinea palms. We support calls for the multivariate assessment of the mid-domain effect on an equal footing with other potential explanations of species richness. [source] The relationship of GMA to counterproductive work behavior revisitedEUROPEAN JOURNAL OF PERSONALITY, Issue 6 2009Bernd Marcus Abstract Recent research reported that general mental ability (GMA) predicted counterproductive work behavior (CWB), whereas some previous studies failed to find such a relationship. We tested occupational homogeneity of the sample and criterion measurement as two potential explanations for these inconsistencies. Study 1 replicated major design features of one previous study, which found no GMA,CWB relation in a heterogeneous sample, with occupationally homogeneous groups. Results confirmed previous null findings, indicating no effect of sample homogeneity. In Study 2, using a controlled laboratory setting, GMA was again unrelated to self-reported CWB, but partially predicted observed CWB negatively. Combined findings suggest that GMA is consistently unrelated to CWB self-reports but may predict objectively measured CWB independently of the likelihood of being caught. Copyright © 2009 John Wiley & Sons, Ltd. [source] Insider Trading after Repurchase Tender Offer Announcements: Timing versus Informed TradingFINANCIAL MANAGEMENT, Issue 1 2010Henock Louis Abnormally high net insider selling is commonly observed after repurchase tender offer (RTO) announcements although, on average, firms experience positive abnormal returns in the years after the repurchases. We explore two potential explanations: liquidity trade timing and informed trading. Consistent with the notion that fixed price RTOs are more likely than Dutch-auction RTOs to signal undervaluation, the results suggest that insider selling after fixed price RTO announcements are driven largely by insiders who time their trades with the repurchase announcements. In contrast, selling after Dutch-auction RTOs seems to be driven primarily by informed traders who exploit mispricing associated with the repurchase announcements. [source] Behavioral Adaptation, Confidence, and Heuristic-Based Explanations of the Probing EffectHUMAN COMMUNICATION RESEARCH, Issue 4 2001Timothy R. Levine Researchers have found that asking probing questions of message sources does not enhance deception detection accuracy. Probing does, however, increase recipient and observer perceptions of source honesty, a finding we label the probing effect. This project examined 3 potential explanations for the probing effect: behavioral adaptation, confidence bias, and a probing heuristic. In Study 1, respondents (N = 337) viewed videotaped interviews in which probes were present or not present, and in which message source behaviors were controlled. Inconsistent with the behavioral adaptation explanation, respondents perceived probed sources as more honest than nonprobed sources, despite the fact that source behaviors were constant across conditions. The data also were inconsistent with the confidence bias explanation. Studies 2 and 3 investigated the probing heuristic explanation. The data from Study 2 (N = 136) were ambiguous, but the results of third study (N = 143) were consistent with the heuristic processing explanation of the probing effect. [source] | |||||||||||||||||||||||||