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Primary Determinant (primary + determinant)
Selected AbstractsEnter at your own risk: HMO participation and enrollment in the Medicare risk marketECONOMIC INQUIRY, Issue 3 2000J Abraham We examine HMO participation and enrollment in the Medicare risk market for the years 1990 to 1995. We develop a profit-maximization model of HMO behavior, which explicitly considers potential linkages between an HMO's production decision in the commercial enrollee market and its participation and production decisions in the Medicare risk market. Our results suggest that the payment rate is a primary determinant of HMO participation, while the price of a supplemental Medicare insurance policy positively affects HMO Medicare enrollment. We also find empirical support for the existence of complementarities in the joint production of an HMO's commercial and Medicare products. [source] A common-features analysis of Amsterdam and London financial markets during the eighteenth centuryECONOMIC INQUIRY, Issue 1 2000G Dempster We examine the financial linkage between the London and Amsterdam financial markets using stock prices recorded in each market over the period 1723-94 in conjunction with tests for common trends, cycles, and regime shifts. These tests reveal a surprising degree of integration between the markets as their prices move together in both the short and long run. Moreover, shocks to the assets translate quickly and accurately between markets. It also appears that Dutch investment did not destabilize London markets and stock prices in London were the primary determinant of prices in Amsterdam. [source] Diversity and functional importance of coral-feeding fishes on tropical coral reefsFISH AND FISHERIES, Issue 3 2008Andrew J. Cole Abstract Fishes that feed from live corals (corallivores) are a conspicuous component of healthy coral reef environments. However, knowledge of the occurrence and ecological significance of this feeding mode is fragmentary. Historically, very few fish were considered capable of feeding from live coral, and those few that did were considered ecologically insignificant. More recently, the role of corallivores has been re-evaluated; published records document 128 corallivorous fish species from 11 different families, with 69 of these belonging to the family Chaetodontidae. Other families, including the Labridae, Tetraodontidae, Balistidae, Monacanthidae, Pomacentridae and Scaridae, all have between seven and ten coral-feeding species. One-third of coral-feeding fishes feed almost exclusively on corals, with more than 80% of their diet based on coral. Corallivorous fish show distinct prey preferences and consume only a small subset of available corals, usually the genera Acropora, Pocillopora and Porites. This selective predation by corallivores can limit abundance and distribution of preferred corals. Chronic predation by corallivores may also exacerbate effects of coral disturbance (e.g. climate-induced coral bleaching), impeding reef recovery and causing further coral loss. Conversely, the cover of preferred corals can be a primary determinant of corallivore abundance and physiological condition. Owing to this close association, obligate corallivores invariably decline in response to loss of coral cover. Increased knowledge of the number of corallivores and their diets suggest that this feeding mode is more important to coral reef food webs than traditionally thought. [source] Firm-specific human capital and compensation organizational tenure profiles: An archival analysis of salary data for itHUMAN RESOURCE MANAGEMENT, Issue 3 2007Sandra A. Slaughter We examine determinants of IT compensation using archival salary data from 2,251 IT professionals in Singapore. Consistent with human capital theory, we find that professionals in IT jobs requiring more firm-specific human capital are paid more than those in jobs requiring less firm-specific human capital. Moreover, compensation increases with organizational tenure at an increasing rate for professionals in higher firm-specific human capital IT jobs, but at a decreasing rate for those in lower firm-specific human capital IT jobs. Our results reveal firm-specific human capital as a primary determinant of compensation and a moderator of IT compensation-organizational tenure profiles. © 2007 Wiley Periodicals, Inc. [source] GAAP versus The Street: An Empirical Assessment of Two Alternative Definitions of EarningsJOURNAL OF ACCOUNTING RESEARCH, Issue 1 2002Mark T. Bradshaw Managers, security analysts, investors, and the press rely increasingly on modified definitions of GAAP net income, known by such names as "operating" and "pro forma" earnings. We document this phenomenon and discuss competing explanations for the recent rise in the use of such modified earnings numbers and implications for the interpretation of related accounting research. Our results show that over the past 20 years there has been a dramatic increase in the frequency and magnitude of cases where "GAAP" and "Street" earnings differ. Further, there is a very strong bias toward the reporting of a Street earnings number that exceeds the GAAP earnings number. We also show that the market response to the Street earnings number has displaced GAAP earnings as a primary determinant of stock prices. Finally, through an analysis of earnings releases, we show that management has taken a proactive role in defining and emphasizing the Street number when communicating to analysts and investors. [source] National-scale metacommunity dynamics of carabid beetles in UK farmlandJOURNAL OF ANIMAL ECOLOGY, Issue 2 2008David R. Brooks Summary 1Understanding the wide-scale processes controlling communities across multiple sites is a foremost challenge of modern ecology. Here, data from a nation-wide network of field sites are used to describe the metacommunity dynamics of arable carabid beetles. This is done by modelling how communities are structured at a local level, by changes in the environment of the sampled fields and, at a regional level, by fitting spatial parameters describing latitudinal and longitudinal gradients. 2Local and regional processes demonstrated independent and significant capacities for structuring communities. Within the local environment, crop type was found to be the primary determinant of carabid community composition. The regional component included a strong response to a longitudinal gradient, with significant increases in diversity in an east-to-west direction. 3Carabid metacommunities seem to be structured by a combination of species sorting dynamics, operating at two different, but equally important, spatial scales. At a local scale, species are sorted along a resource gradient determined by crop type. At a wider spatial scale species appear to be sorted along a longitudinal gradient. 4Nation-wide trends in communities coincided with known gradients of increased homogeneity of habitat mosaics and agricultural intensification. However, more work is required to understand fully how communities are controlled by the interaction of crops with changes in landscape structure at different spatial scales. 5We conclude that crop type is a powerful determinant of carabid biodiversity, but that it cannot be considered in isolation from other components of the landscape for optimal conservation policy. [source] The role of rainfall and predators in determining synchrony in reproduction of savanna trees in Serengeti National Park, TanzaniaJOURNAL OF ECOLOGY, Issue 1 2007SIMON A. R. MDUMA Summary 1We examined the factors determining synchrony in reproduction in nine Acacia and six other tree species in the Serengeti ecosystem. 2We test two hypotheses: (i) an abiotic hypothesis where the primary determinant of synchrony is an adaptation to water availability; and (ii) biotic hypotheses where these adaptations to water can be further refined by additional adaptations to avoid predators, or attract seed and fruit dispersers. 3Flowering and fruiting were recorded monthly for individually marked trees during 1997,2004. Flowering in different species occurs semi-annually, annually or, in the case of one species, once every 2 years. For most species synchrony of flowering was correlated with seasonal rainfall, with lags related to the mean height of the species; small species flowered during the rains while larger species flowered in the dry season. Fruiting seasons occurred at the end of the rains irrespective of the flowering season. 4Most species showed flowering synchrony greater than expected from the distribution of rainfall. This may be related to avoidance of insect seed predators through predator satiation. Two Acacias showed multi-annual fruiting (masting), possibly as a predator avoidance mechanism. Acacia tortilis has two flowering seasons: a dry season flowering with early abortion of pods and a wet season flowering producing successful fruits. 5Two species of Commiphora appeared to be synchronized so as to attract birds that disperse seeds. Acacia tortilis produced indehiscent pods attractive to ungulates, possibly to kill bruchid beetles during digestion and so increase seed viability. 6Our results suggest that synchrony in these trees is caused by a strong interaction between abiotic and biotic factors. Closely related species have different reproductive patterns of synchrony that seem to be adapted to different combinations of rainfall, predators and dispersers. Rainfall is the primary determinant but the activities of predators and dispersers increase the degree of synchrony. [source] Blastocyst embryo transfer is the primary determinant for improved outcomes in oocyte donation cyclesJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 2 2010Natalie Porat Abstract Aim:, Using oocyte donation cycles as an ideal model, we sought to compare pregnancy and implantation rates in cleavage stage (day 3) versus blastocyst stage (day 6) embryo transfers (ET); assess the predictive value of blastocyst formation rates based on cleavage cell stage and morphology grade; and evaluate the ability to predict formation of high quality (HQ) blastocysts. Methods:, Ninety three consecutive oocyte donation cycles from July 2003 to August 2005 were retrospectively evaluated and analyzed to determine if either resulted in a cleavage stage (n = 30) or blastocyst (n = 45) ET. The primary outcomes measured pregnancy rates, the percent development of HQ blastocysts based on day 3 embryo status, and the ability to select day 3 embryos suitable for transfer among four blinded evaluators by assessing their day 6 embryo outcome. Results:, Cleavage stage ET resulted in significantly lower pregnancy rates, clinical pregnancy rates, and implantation rates (47% [n = 14/30]; 40% [n = 12/30] and 27 ± 7%) compared to blastocyst stage (82% [n = 37/45]; 73% [n = 33/45] and 64 ± 6% [±SE], P < 0.01). In total, HQ blastocysts resulted from high and good quality day 3 embryos 35% (191/546) and 17% (93/546), respectively. Blinded evaluation revealed at least one, two or all three day 3 embryos were correctly selected for ET on day 6, 97%, 67% and 19%, respectively. Conclusion:, Day 6 ET resulted in significantly better clinical outcomes compared to day 3 ET. While day 3 status is not predictive of blastocyst quality, the selection of at least one day 3 embryo ultimately suitable for blastocyst ET underscores the significance of optimal endometrial receptivity. [source] Multivariate modeling of encapsulation and release of an ionizable drug from polymer microspheresJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 12 2009Hagar I. Labouta Abstract In the formulation of polymer microspheres (MSs) loaded with verapamil hydrochloride (VRP), a low molecular weight ionizable drug, by W/O/W emulsification, the pH of the external aqueous phase proved to be a primary determinant of both IE and drug release behavior. Increasing the pH of the external aqueous phase enhanced IE (,100% at pH 8.4). This was associated with a considerable increase in initial release rate at pH 1.2. Two multivariate methods, factorial analysis (FA) and artificial neural network (ANN), were used to investigate the impact of the combined effect of the external phase pH and other parameters (polymer concentration and initial drug load) on MS characteristics; IE, initial drug release, MS size and yield. FA indicated that the external aqueous phase pH affected all responses, with a particularly strong correlation with IE in addition to a combined synergistic effect with polymer concentration on MS size. ANN showed better internal and external predictive ability of responses compared to FA. The ANN model developed in the study can be successfully used for multivariate modeling of the encapsulation and release of VRP and similar drug salts from hydrophobic polymer MSs prepared by multiple emulsification in addition to other MS characteristics. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:4603,4615, 2009 [source] Incentives and Standards in Agency ContractsJOURNAL OF PUBLIC ECONOMIC THEORY, Issue 2 2005ROBERT G. CHAMBERS This paper studies the structure of state-contingent contracts in the presence of moral hazard and multitasking. Necessary and sufficient conditions for the presence of multitasking to lead to fixed payments instead of incentive schemes are identified. It is shown that the primary determinant of whether multitasking leads to higher or lower powered incentives is the role that noncontractible outputs play in helping the agent deal with the production risk associated with the observable and contractible outputs. When the noncontractible outputs are risk substitutes and are socially undesirable, standards are never optimal. If the noncontractible outputs are socially desirable, standards are never optimal if the noncontractible outputs play a risk-complementary role. [source] Splitting the Baby: An Empirical Test of Rules of Thumb in Regulatory Price SettingKYKLOS INTERNATIONAL REVIEW OF SOCIAL SCIENCES, Issue 3 2005T. Randolph Beard Summary This article provides an empirical evaluation of a recent and important exercise in regulatory price setting in the United States. The 1996 Telecommunications Act required incumbent local phone companies to sell components of their network to rival firms at regulated prices, and the prices for these ,unbundled network elements' were based primarily on independent estimates of forward-looking economic costs. Our econometric analysis reveals that, while cost is a primary determinant of element prices, the prices also reflect foregone retail profits for incumbent firms. Statistical tests suggest that ,splitting the baby' is an accurate positivist description of public agency behavior. [source] Efficiency in pre-merger and post-merger non-bank financial institutionsMANAGERIAL AND DECISION ECONOMICS, Issue 8 2001Andrew C. WorthingtonArticle first published online: 19 OCT 200 A two-part process is employed to analyse the role of efficiency in merger and acquisition (M&A) activity in Australian credit unions during the period 1993,1997. The measures of efficiency are derived using the non-parametric technique of data envelopment analysis. The first part uses panel data in the probit model to relate pure technical efficiency, along with other managerial, regulatory and financial factors, to the probability of merger activity, either as an acquiring or acquired entity. The results indicate that loan portfolio diversification, management ability, earnings and asset size are a significant influence on the probability of acquisition, though the primary determinant of being acquired is smaller asset size. The second part uses a tobit model adapted to a panel framework to analyse post-merger efficiency. Mergers appear to have improved both pure technical efficiency and scale efficiency in the credit union industry. Copyright © 2001 John Wiley & Sons, Ltd. [source] Passive smoking is a major determinant of exhaled nitric oxide levels in allergic asthmatic childrenALLERGY, Issue 4 2010Y. Laoudi To cite this article: Laoudi Y, Nikasinovic L, Sahraoui F, Grimfeld A, Momas I, Just J. Passive smoking is a major determinant of exhaled nitric oxide levels in allergic asthmatic children. Allergy 2010; 65: 491,497. Abstract Background:, Fraction of exhaled nitric oxide (FeNO) is considered, by some authors, to be a treatment follow-up parameter in allergic asthmatics. However, factors such as active smoking can influence NO production and must be taken into account in the interpretation of FeNO values. In children, the evidence in favour of an impact of passive smoking (PS) on FeNO values is controversial. The aim of this study was to evaluate the impact of chronic PS on FeNO in allergic asthmatic children. Methods:, Seventy nontreated allergic asthmatic children over 5 years of age, exposed and unexposed to PS, underwent measurement of FeNO, spirometry, and allergic tests (skin prick tests, total and specific serum IgE, and blood eosinophilia). Children were considered to be exposed to PS when at least 1 cigarette per day was declared to be smoked at home. Results:, Geometric mean FeNO value in 22 children exposed to PS was 26.3 ± 1.5 ppb vs 56.3 ± 1.7 ppb in 48 children unexposed (P < 0.001). After adjustment for age, blood eosinophilia, allergic sensitizations, total IgE, dust mite sensitization and asthma severity, multivariate analysis showed that PS exposure was negatively associated with FeNO values (P = 0.0001) and was the primary determinant of FeNO variations. Conclusion:, Passive smoking lowers FeNO, and might be a major determinant of FeNO levels in nontreated allergic asthmatic children. [source] Dispersal ecology versus host specialization as determinants of ectoparasite distribution in brood parasitic indigobirds and their estrildid finch hostsMOLECULAR ECOLOGY, Issue 1 2007CHRISTOPHER N. BALAKRISHNAN Abstract Brood parasitic birds offer a unique opportunity to examine the ecological and evolutionary determinants of host associations in avian feather lice (Phthiraptera). Brood parasitic behaviour effectively eliminates vertical transfer of lice between parasitic parents and offspring at the nest, while at the same time providing an opportunity for lice associated with the hosts of brood parasites to colonize the brood parasites as well. Thus, the biology of brood parasitism allows a test of the relative roles of host specialization and dispersal ecology in determining the host,parasite associations of birds and lice. If the opportunity for dispersal is the primary determinant of louse distributions, then brood parasites and their hosts should have similar louse faunas. In contrast, if host-specific adaptations limit colonization ability, lice associated with the hosts of brood parasites may be unable to persist on the brood parasites despite having an opportunity for colonization. We surveyed lice on four brood parasitic finch species (genus Vidua), their estrildid finch host species, and a few ploceid finches. While Brueelia lice were found on both parasitic and estrildid finches, a molecular phylogeny showed that lice infesting the two avian groups belong to two distinct clades within Brueelia. Likewise, distinct louse lineages within the amblyceran genus Myrsidea were found on estrildid finches and the parasitic pin-tailed whydah (Vidua macroura), respectively. Although common on estrildid finches, Myrsidea lice were entirely absent from the brood parasitic indigobirds. The distribution and relationships of louse species on brood parasitic finches and their hosts suggest that host-specific adaptations constrain the ability of lice to colonize new hosts, at least those that are distantly related. [source] Effects of species diversity on the primary productivity of ecosystems: extending our spatial and temporal scales of inferenceOIKOS, Issue 3 2004Bradley J. Cardinale The number of studies examining how species diversity influences the productivity of ecosystems has increased dramatically in the past decade as concern about global loss of biodiversity has intensified. Research to date has greatly improved our understanding of how, when, and why species loss alters primary production in ecosystems. However, because experiments have been performed at rather small spatial and short temporal scales, it is unclear whether conclusions can be readily extrapolated to the broader scales at which natural communities are most likely to influence ecosystem functioning. Here we develop a simple patch-dynamics model to examine some of the scale-dependent and independent qualities of the diversity-productivity relationship. We first simulate a typical diversity-productivity experiment and show that the influence of species richness on productivity is temporally dynamic, growing stronger through successional time. This holds true irrespective of whether resource partitioning or a sampling effect is the underlying mechanism. We then increase the spatial scale of the simulation from individual patches to a region consisting of many patch types. Results suggest that the diversity-productivity relationship is not influenced by spatial scale per se, but that the mechanism producing the relationship can change from sampling effects within individual patches to resource partitioning across patch types composing the region. This change occurs even though model dynamics are the same at both scales, suggesting that sampling effects and resource partitioning can represent different descriptions of the same biological processes operating concurrently at differing scales of observation. Lastly, we incorporate regional processes of dispersal and disturbance into the model and show that these processes can amplify the effect of species richness on productivity, resulting in patterns not easily anticipated from experiments. We conclude that the relative control of community structure by local versus regional processes may be a primary determinant of the diversity-productivity relationship in natural ecosystems. Therefore, past experiments having focused only on local processes might not reflect patterns and processes underlying diversity-productivity relationships in communities where disturbance and dispersal regulate species biomasses. [source] The effect of perceived length on visuomotor localizationOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2001Nick Fogt Summary Purpose: The purpose of this experiment was to study visuomotor localization in the presence of either a horizontal array of equally spaced dots or a thin horizontal line. Methods: Pointing behavior was used to assess directional localization. In experiment 1, subjects were made myopic using a contact lens and then corrected with a spectacle lens. Subjects were tested in the presence and absence of a regularly spaced, horizontal array of dots with and without the contact lens/spectacle combination. In experiment 2, subjects wore the contact lens/spectacle in all cases. Some subjects were tested in the presence and then in the absence of a regularly spaced, horizontal array of dots while the order of conditions was reversed for other subjects. In experiments 3 and 4, subjects were tested without the contact lens/spectacle combination. In experiment 3, subjects were tested in the absence and then in the presence of a regularly spaced, horizontal arrays of dots. In experiment 4, subjects were tested in the absence and then in the presence of a thin horizontal line. Results: In experiment 1, in the absence of the array of dots, subjects undershot targets with the contact lens/spectacle combination. When the array was present, pointing with the contact lens/spectacle combination was accurate. In experiment 2, subjects undershot targets in the absence of the array of dots if this condition was performed first. If the array was present in the initial condition, the pointing undershoot in the second condition (array absent) was reduced. In all cases, the pointing undershoot was reduced in the presence of the array. In experiments 3 and 4, a pointing overshoot was found in the presence of an array of dots or a thin line. Conclusions: It is concluded that extraretinal eye position information is not the primary determinant of visuomotor localization in the presence of a horizontal contour. The overshoot produced by a horizontal contour may be related to a length illusion brought about by spatial filtering in the visual system or inaccurate distance judgments. [source] The association between antidepressant use and hypoglycaemia in diabetic patients: a nested case,control study,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 4 2008Hieronymus J. Derijks PharmD Abstract Purpose Hypoglycaemia is a limiting factor for glycaemic management of diabetes with intensive insulin and/or oral antidiabetic drug (OAD) regimen. Case reports suggest that antidepressants may interfere with blood glucose metabolism in patients with diabetes mellitus potentially increasing the risk of clinically relevant hypoglycaemia. Comorbid depression treated with antidepressants could therefore further complicate glycaemic control. We have carried out a nested case,control study among diabetic patients to assess the risk of hypoglycaemia requiring hospitalisation associated with the use of antidepressants. Methods Diabetic patients treated with insulin and/or OADs were selected from the Dutch Pharmo system. Exposure to antidepressants was the primary determinant investigated. Use of antidepressants was further subclassified based on the receptor binding profile to investigate whether specific pharmacological properties could explain a potential influence on glucose homeostasis. Conditional logistic regression was used to estimate odds ratios and to adjust for confounding factors. Results From the base cohort (40 600 patients), 549 (1.35%) cases were identified and 1897 controls were selected. Current use of any antidepressant was not associated with a significantly higher risk of hypoglycaemia requiring hospitalisation (OR: 1.36 (95%CI: 0.84,2.20)). A trend for a higher risk on hypoglycaemia was identified for antidepressants with high affinity for the serotonin reuptake transporter. The risk on severe hypoglycaemia was increased after 3 years of use (OR: 2.75 (95%CI: 1.31,5.77)). Conclusions It is important for diabetic patients using antidepressants for more than 3 years to pay attention for symptoms of hypoglycaemia and strict blood glucose self-monitoring. Copyright © 2008 John Wiley & Sons, Ltd. [source] Wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) multiple inositol polyphosphate phosphatases (MINPPs) are phytases expressed during grain filling and germination,PLANT BIOTECHNOLOGY JOURNAL, Issue 2 2007Giuseppe Dionisio Summary At present, little is known about the phytases of plant seeds in spite of the fact that this group of enzymes is the primary determinant for the utilization of the major phosphate storage compound in seeds, phytic acid. We report the cloning and characterization of complementary DNAs (cDNAs) encoding one of the groups of enzymes with phytase activity, the multiple inositol phosphate phosphatases (MINPPs). Four wheat cDNAs (TaPhyIIa1, TaPhyIIa2, TaPhyIIb and TaPhyIIc) and three barley cDNAs (HvPhyIIa1, HvPhyIIa2 and HvPhyIIb) were isolated. The open reading frames ranged from 1548 to 1554 bp and the level of homology between the barley and wheat proteins ranged from 90.5% to 91.9%. All cDNAs contained an N-terminal signal peptide encoding sequence, and a KDEL-like sequence, KTEL, was present at the C-terminal, indicating that the enzyme was targeted to and retained within the endoplasmic reticulum. Expression of TaPhyIIa2 and HvPhyIIb in Escherichia coli revealed that the MINPPs possessed a significant phytase activity with narrow substrate specificity for phytate. The pH and temperature optima for both enzymes were pH 4.5 and 65 °C, respectively, and the Km values for phytate were 246 and 334 µm for the wheat and barley recombinant enzymes, respectively. The enzymes were inhibited by several metal ions, in particular copper and zinc. The cDNAs showed significantly different temporal and tissue-specific expression patterns during seed development and germination. With the exception of TaPhyIIb, the cDNAs were present during late seed development and germination. We conclude that MINPPs constitute a significant part of the endogenous phytase potential of the developing and germinating barley and wheat seeds. [source] Examining the Mediators of Agenda Setting: A New Experimental Paradigm Reveals the Role of EmotionsPOLITICAL PSYCHOLOGY, Issue 6 2007Joanne M. Miller Over two decades ago, Maxwell McCombs (1981) called for serious investigation of the mediators and moderators of media effects. Without rich, theory-based understanding of why and when agenda setting happens, he said, we cannot truly appreciate the phenomenon or its implications. This manuscript reports the results of a new experimental paradigm to examine the cognitive mechanism(s) of agenda setting. Challenging the assumption that accessibility is responsible for shifts in importance judgments, the current research shows that the content of news stories is a primary determinant of agenda setting. Rather than solely relying on what is accessible in memory, people pay attention to the content of news stories,to the extent that the content arouses negative emotions, national importance judgments follow. [source] Success in Global New Product Development: Impact of Strategy and the Behavioral Environment of the FirmTHE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 2 2010Ulrike De Brentani Product innovation and the trend toward globalization are two important dimensions driving business today, and a firm's global new product development (NPD) strategy is a primary determinant of performance. Succeeding in this competitive and complex market arena calls for corporate resources and strategies by which firms can effectively tackle the challenges and opportunities associated with international NPD. Based on the resource-based view (RBV) and the entrepreneurial strategic posture (ESP) literature, the present study develops and tests a model that emphasizes the resources of the firm as primary determinants of competitive advantage and, thus, of superior performance through the strategic initiatives that these enable. In the study, global NPD programs are assessed in terms of three dimensions: (1) the organizational resources or behavioral environment of the firm relevant for international NPD,specifically, the global innovation culture of the firm and senior management involvement in the global NPD effort; (2) the global NPD strategies (i.e., global presence strategy and global product harmonization strategy) chosen for expanding and exploiting opportunities in international markets; and (3) global NPD program performance in terms of shorter- and longer-term outcome measures. These are modeled in antecedent terms, where the impact of the resources on performance is mediated by the NPD strategy of the firm. Based on data from 432 corporate global new product programs (North America and Europe, business-to-business, services and goods), a structural model testing for the hypothesized mediation effects was substantially supported. Specifically, having an organizational posture that, at once, values innovation plus globalization, as well as a senior management that is active in and supports the international NPD effort leads to strategic choices that are focused on making the firm truly global in terms of both market coverage and product offering. Further, the two strategies,global presence and global product harmonization,were found to be significant mediators of the firm's behavioral environment in terms of impact on performance of global NPD programs. [source] Upstream Solutions: Does the Supplemental Security Income Program Reduce Disability in the Elderly?THE MILBANK QUARTERLY, Issue 1 2008PAMELA HERD Context: The robust relationship between socioeconomic factors and health suggests that social and economic policies might substantially affect health, while other evidence suggests that medical care, the main focus of current health policy, may not be the primary determinant of population health. Income support policies are one promising avenue to improve population health. This study examines whether the federal cash transfer program to poor elderly, the Supplemental Security Income (SSI) program, affects old-age disability. Methods: This study uses the 1990 and 2000 censuses, employing state and year fixed-effect models, to test whether within-state changes in maximum SSI benefits over time lead to changes in disability among people aged sixty-five and older. Findings: Higher benefits are linked to lower disability rates. Among all single elderly individuals, 30 percent have mobility limitations, and an increase of $100 per month in the maximum SSI benefit caused the rate of mobility limitations to fall by 0.46 percentage points. The findings were robust to sensitivity analyses. First, analyses limited to those most likely to receive SSI produced larger effects, but analyses limited to those least likely to receive SSI produced no measurable effect. Second, varying the disability measure did not meaningfully alter the findings. Third, excluding the institutionalized, immigrants, individuals living in states with exceptionally large benefit changes, and individuals living in states with no SSI supplements did not change the substantive conclusions. Fourth, Medicaid did not confound the effects. Finally, these results were robust for married individuals. Conclusions: Income support policy may be a significant new lever for improving population health, especially that of lower-income persons. Even though the findings are robust, further analyses are needed to confirm their reliability. Future research should examine a variety of different income support policies, as well as whether a broader range of social and economic policies affect health. [source] Clinical progression in Parkinson disease and the neurobiology of axonsANNALS OF NEUROLOGY, Issue 6 2010Hsiao-Chun Cheng PhD Despite tremendous growth in recent years in our knowledge of the molecular basis of Parkinson disease (PD) and the molecular pathways of cell injury and death, we remain without therapies that forestall disease progression. Although there are many possible explanations for this lack of success, one is that experimental therapeutics to date have not adequately focused on an important component of the disease process, that of axon degeneration. It remains unknown what neuronal compartment, either the soma or the axon, is involved at disease onset, although some have proposed that it is the axons and their terminals that take the initial brunt of injury. Nevertheless, this concept has not been formally incorporated into many of the current theories of disease pathogenesis, and it has not achieved a wide consensus. More importantly, in view of growing evidence that the molecular mechanisms of axon degeneration are separate and distinct from the canonical pathways of programmed cell death that mediate soma destruction, the possibility of early involvement of axons in PD has not been adequately emphasized as a rationale to explore the neurobiology of axons for novel therapeutic targets. We propose that ongoing degeneration of axons, not cell bodies, is the primary determinant of clinically apparent progression of disease, and that future experimental therapeutics intended to forestall disease progression will benefit from a new focus on the distinct mechanisms of axon degeneration. ANN NEUROL 2010;67:715,725 [source] Home range and movements of male feral cats (Felis catus) in a semiarid woodland environment in central AustraliaAUSTRAL ECOLOGY, Issue 1 2001G. P. EDWARDS Abstract There is a paucity of data on the movement patterns of feral cats in Australia. Such data can be used to refine control strategies and improve track-based methods of monitoring populations of feral cats. In this study the home ranges and movements of male feral cats were examined over 3.5 years in a semiarid woodland environment in central Australia. Two home range estimators were used in the examination: (i) minimum convex polygon (MCP); and (ii) fixed kernel. The most widely used method of estimating home range in feral cats is MCP, while the fixed kernel method can be used to identify core areas within a home range. On the basis of the MCP method, the long-term home ranges of feral cats in central Australia were much larger than those recorded elsewhere (mean, 2210.5 ha). Twenty-four hour home ranges were much smaller (mean, 249.7 ha) and feral cats periodically shifted their 24 h ranges within the bounds of their long-term home ranges. Core area analysis indicated marked heterogeneity of space use by male feral cats. Several instances where feral cats moved large distances (up to 34 km) were recorded. These long distance movements may have been caused by nutritional stress. Using data from the literature, it is shown that prey availability is a primary determinant of long-term home range size in feral cats. The relevance of the results to the design of management strategies for feral cats in central Australia is also discussed. [source] Home range and movements of male feral cats (Felis catus) in a semiarid woodland environment in central AustraliaAUSTRAL ECOLOGY, Issue 1 2001G. P. Edwards Abstract There is a paucity of data on the movement patterns of feral cats in Australia. Such data can be used to refine control strategies and improve track-based methods of monitoring populations of feral cats. In this study the home ranges and movements of male feral cats were examined over 3.5 years in a semiarid woodland environment in central Australia. Two home range estimators were used in the examination: (i) minimum convex polygon (MCP); and (ii) fixed kernel. The most widely used method of estimating home range in feral cats is MCP, while the fixed kernel method can be used to identify core areas within a home range. On the basis of the MCP method, the long-term home ranges of feral cats in central Australia were much larger than those recorded elsewhere (mean, 2210.5 ha). Twenty-four hour home ranges were much smaller (mean, 249.7 ha) and feral cats periodically shifted their 24 h ranges within the bounds of their long-term home ranges. Core area analysis indicated marked heterogeneity of space use by male feral cats. Several instances where feral cats moved large distances (up to 34 km) were recorded. These long distance movements may have been caused by nutritional stress. Using data from the literature, it is shown that prey availability is a primary determinant of long-term home range size in feral cats. The relevance of the results to the design of management strategies for feral cats in central Australia is also discussed. [source] Gene Induction by Phenobarbital: An Update on an Old Question that Receives Key Novel Answers,BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 3 2001Laurent Corcos The drug is the representative of a myriad of lipophilic molecules able to evoke a pleiotropic response in the liver and also in prokaryotes and flies. A great deal of novel information has been obtained in recent years regarding the mechanism of cytochrome P450 (CYP) gene induction by phenobarbital. Most importantly, a nuclear orphan receptor, the constitutive androstane receptor has been identified as a primary determinant of the transcriptional activation of CYP genes in response to phenobarbital-like inducers in mammals. Another nuclear receptor, the pregnane X receptor can also mediate some of the phenobarbital response, but the functional overlap of the two inductive pathways is only partial. The response of mammalian CYP2B genes to phenobarbital was abolished in the liver of mice carrying a null allele of the constitutive androstane receptor gene, whereas that of CYP3A genes was lost in pregnane X receptor knock-out mice. [source] Polyethylenimine-coated albumin nanoparticles for BMP-2 deliveryBIOTECHNOLOGY PROGRESS, Issue 4 2008Sufeng Zhang Abstract Nanoparticle (NP)-based delivery has gained importance for improving the potency of therapeutic agents. The bovine serum albumin (BSA) NPs, obtained by a coacervation process, was modified by electrostatic adsorption of cationic polyethylenimine (PEI) to NP surfaces for delivery of bone-inducing growth factor, bone morphogenetic protein-2 (BMP-2). Different concentrations of PEI were utilized for coating BSA NPs to stabilize the colloidal system and to control the release of BMP-2. The NPs were characterized by size and zeta potential measurements, as well as by Scanning Electron Microscopy and Atomic Force Microscopy. The encapsulation efficiency was typically >90% in all NP preparations. In vitro release kinetics showed that the PEI concentration used for coating the NPs efficiently controlled the release of BMP-2, demonstrating a gradual slowing, sustained release pattern during a 10-day study period. The bioactivity of the encapsulated BMP-2 and the toxicity of the NPs were examined by the alkaline phosphatase (ALP) induction assay and the MTT assay, respectively, using C2C12 cells. The results indicated that PEI was the primary determinant of NP toxicities, and BSA NPs coated with 0.1 mg/mL PEI demonstrated tolerable toxicity, retained the bioactivity of BMP-2, and efficiently slowed the release rate of BMP-2. We conclude that BMP-2 encapsulated in BSA NPs might be an efficient way to deliver the protein for in vivo bone induction. [source] Abundance , occupancy relationships in macrofauna on exposed sandy beaches: patterns and mechanismsECOGRAPHY, Issue 5 2004Matthew T. Frost We studied the relationship between abundance and extent of occupancy of 158 species of macrofauna inhabiting 66 sandy beaches around the coast of Great Britain. We also used these data to test the predictions of two hypotheses proposed to explain positive abundance-occupancy relationships. We found a strong positive relationship between abundance and extent of occupancy; this pattern was apparent in taxonomic subsets of organisms which have contrasting reproductive and dispersal traits such as planktotrophic/lecithotrophic development in the plankton vs brood development under parental care. Moreover, the abundance-occupancy relationships in these taxonomic subsets had statistically indistinguishable slopes, and elevation. We propose that this lends support to the notion that differences in population structure such as the tendency to form metapopulations may not be primary determinants of the abundance-occupancy pattern in these taxa as proposed by the rescue/metapopulation hypothesis. To test the predictions of the niche-breadth hypothesis we derived values describing the range of sediment grain-sizes exploited by members of two taxonomic subgroups: amphipods and bivalves. We found a weak, statistically non-significant relationship between this niche-breadth measure and occupancy in bivalves which have been shown to respond to grain-size in previous studies, however this was negated after correction for possible artefacts of sampling effort. All other relationships between abundance or occupancy and grain-size range were non-significant. The consistency of the demonstrated abundance-occupancy relationship with those demonstrated in other studies of primarily terrestrial fauna indicates some shared mechanistic explanation, but our data fail to provide support for the two mechanistic hypotheses investigated. [source] Modelling the effect of buoyancy on the transport of anchovy (Engraulis capensis) eggs from spawning to nursery grounds in the southern Benguela: an IBM approachFISHERIES OCEANOGRAPHY, Issue 3 2003C. Parada Abstract An individual-based model (IBM) was used to investigate the effects of physical and biological variables on the transport via a jet current of anchovy (Engraulis capensis) eggs from spawning to the nursery grounds in the southern Benguela ecosystem. As transport of eggs and early larvae is considered to be one of the major factors impacting on anchovy recruitment success, this approach may be useful to understand further the recruitment variability in this economically and ecologically important species. By coupling the IBM to a 3D hydrodynamic model of the region called Plume, and by varying parameters such as the spatial and temporal location of spawning, particle buoyancy, and the depth range over which particles were released, we could assess the influences of these parameters on transport success. A sensitivity analysis using a General Linear Model identified the primary determinants of transport success in the various experimental simulations, and model outputs were examined and compared with patterns observed in field studies. Model outputs compared well with observed patterns of vertical and horizontal egg distribution. Particle buoyancy and area of particle release were the major single determinants of transport success, with an egg density of 1.025 g cm,3 maximizing average particle transport success and the western Agulhas Bank being the most successful spawning area. This IBM may be useful as a generic prototype for other upwelling ecosystems. [source] Environmental determinants of vascular plant species richness in the Austrian AlpsJOURNAL OF BIOGEOGRAPHY, Issue 7 2005Dietmar Moser Abstract Aim, To test predictions of different large-scale biodiversity hypotheses by analysing species richness patterns of vascular plants in the Austrian Alps. Location, The Austrian part of the Alps (c. 53,500 km2). Methods, Within the floristic inventory of Central Europe the Austrian part of the Alps were systematically mapped for vascular plants. Data collection was based on a rectangular grid of 5 × 3 arc minutes (34,35 km2). Emerging species richness patterns were correlated with several environmental factors using generalized linear models. Primary environmental variables like temperature, precipitation and evapotranspiration were used to test climate-related hypotheses of species richness. Additionally, spatial and temporal variations in climatic conditions were considered. Bedrock geology, particularly the amount of calcareous substrates, the proximity to rivers and lakes and secondary variables like topographic, edaphic and land-use heterogeneity were used as additional predictors. Model results were evaluated by correlating modelled and observed species numbers. Results, Our final multiple regression model explains c. 50% of the variance in species richness patterns. Model evaluation results in a correlation coefficient of 0.64 between modelled and observed species numbers in an independent test data set. Climatic variables like temperature and potential evapotranspiration (PET) proved to be by far the most important predictors. In general, variables indicating climatic favourableness like the maxima of temperature and PET performed better than those indicating stress, like the respective minima. Bedrock mineralogy, especially the amount of calcareous substrate, had some additional explanatory power but was less influential than suggested by comparable studies. The amount of precipitation does not have any effect on species richness regionally. Among the descriptors of heterogeneity, edaphic and land-use heterogeneity are more closely correlated with species numbers than topographic heterogeneity. Main conclusions, The results support energy-driven processes as primary determinants of vascular plant species richness in temperate mountains. Stressful conditions obviously decrease species numbers, but presence of favourable habitats has higher predictive power in the context of species richness modelling. The importance of precipitation for driving global species diversity patterns is not necessarily reflected regionally. Annual range of temperature, an indicator of short-term climatic stability, proved to be of minor importance for the determination of regional species richness patterns. In general, our study suggests environmental heterogeneity to be of rather low predictive value for species richness patterns regionally. However, it may gain importance at more local scales. [source] Identifying women with severe angiographic coronary diseaseJOURNAL OF INTERNAL MEDICINE, Issue 1 2010C. Kreatsoulas Abstract., Kreatsoulas C, Natarajan MK, Khatun R, Velianou JL, Anand SS (McMaster University; CARING Network, McMaster University; Population Health Research Institute, McMaster University and Hamilton Health Sciences; Interventional Cardiology, Hamilton Health Sciences; Eli Lilly Canada,May Cohen Chair in Women's Health, McMaster University; Michael G. DeGroote-Heart and Stroke Foundation of Ontario Chair in Population Health Research, McMaster University; Population Genomics Program, McMaster University; McMaster University, Hamilton, ON, Canada). Identifying women with severe angiographic coronary disease. J Intern Med 2010; 268:66,74. Objectives., To determine sex/gender differences in the distribution of risk factors according to age and identify factors associated with the presence of severe coronary artery disease (CAD). Design., We analysed 23 771 consecutive patients referred for coronary angiography from 2000 to 2006. Subjects., Patients did not have previously diagnosed CAD and were referred for first diagnostic angiography. Outcome measures., Patients were classified according to angiographic disease severity. Severe CAD was defined as left main stenosis ,50%, three-vessel disease with ,70% stenosis or two-vessel disease including proximal left anterior descending stenosis of ,70%. Univariate and multivariate logistic regression was used to assess the association between risk factors and angina symptoms with severe CAD. Results., Women were less likely to have severe CAD (22.3% vs. 36.5%) compared with men. Women were also significantly older (69.8 ± 10.6 vs. 66.3 ± 10.7 years), had higher rates of diabetes (35.0% vs. 26.6%), hypertension (74.8% vs. 63.3%) and Canadian Cardiovascular Society (CCS) class IV angina symptoms (56.7% vs. 47.8%). Men were more likely to be smokers (56.9% vs. 37.9%). Factors independently associated with severe CAD included age (OR = 1.05; 95% CI 1.05,1.05, P < 0.01), male sex (OR = 2.43; CI 2.26,2.62, P < 0.01), diabetes (OR = 2.00; CI 1.86,2.18, P < 0.01), hyperlipidaemia (OR = 1.50; CI 1.39,1.61, P < 0.01), smoking (OR = 1.10; CI 1.03,1.18, P = 0.06) and CCS class IV symptoms (OR = 1.43; CI 1.34,1.53, P < 0.01). CCS Class IV angina was a stronger predictor of severe CAD amongst women compared with men (women OR = 1.82; CI 1.61,2.04 vs. men OR = 1.28; CI 1.18,1.39, P < 0.01). Conclusions., Women referred for first diagnostic angiography have lower rates of severe CAD compared with men across all ages. Whilst conventional risk factors, age, sex, diabetes, smoking and hyperlipidaemia are primary determinants of CAD amongst women and men, CCS Class IV angina is more likely to be associated with severe CAD in women than men. [source] | |||||||||||||||||||||||||