581 research outputs found

    Blue Ocean vs. Five Forces

    Get PDF
    The article reports on the authors' research in the Netherlands which focused on a profit model in Dutch retail stores and a so-called blue-ocean approach which requires a new market that attracts consumers and increases profits. Topics include the competitive strategy approach to increasing profits. The authors conclude that the blue-ocean strategy or innovation approach is sustainable

    Blue Ocean versus Competitive Strategy: Theory and Evidence

    Get PDF
    Blue ocean strategy seeks to turn strategic management on its head by replacing ‘competitive advantage’ with ‘value innovation’ as the primary goal where firms must create consumer demand and exploit untapped markets. Empirical analysis has been focused on case study evidence and so lacks generality to resolve the debate. We provide a methodological synthesis of the theories enabling us to bring statistical evidence to the debate. Our analysis finds that blue ocean and competitive strategies overlap and managers do not face a discrete either/or decision between each strategy. Our evidence for the Dutch retail industry indicates that blue ocean strategy has prevailed as a dominant long term viable strategy

    Industry Dynamics and Entrepreneurship: An Equilibrium Model

    Get PDF
    This paper conducts the first general equilibrium analysis of the role of entry, exit and profits in industry dynamics. The benefit of our model is twofold. First, to discriminate between entrantsïżœ role of performing the entrepreneurial function of creating disequilibrium and the conventional equilibrating role of moving the industry to a new equilibrium. Second, to discriminate between three aspects of industry dynamics: the effect of entry and exit on market equilibrium, duration of disequilibrium and patterns of adjustment. Using a rich data set of the retail industry, we construct a dynamic simultaneous equilibrium model of profits, entry and exit. We find that indeed entrants play an entrepreneurial function causing long periods of disequilibrium after which a new equilibrium is attained. Moreover, we find ample support for the statement that disequilibrium is the essence of economic progress

    The Dynamics of Entry and Exit

    Get PDF
    The relation between profits and the number of firms in a market is one of the essential topics in the field of industrial organization. Usually, the relation is modeled in an error-correction framework where profits and/or the number of firms respond to out-of-equilibrium situations. In an out-of-equilibrium situation one or both of these variables deviate from some long-term sustainable level. These models predict that in situations of equilibrium, the number of firms does not change and hence, entry equals exit. Moreover, in equilibrium entry and exit are expected to be equal to zero. These predictions are at odds with real life observations showing that entry and exit levels are significantly positive in all markets of substantial size and that entry and exit levels often differ drastically. In this paper we develop a new model for the relation between profit levels and the number of firms by specifying not only an equation for the equilibrium level of profits in a market but also equations for the equilibrium levels of entry and exit. In our empirical application we show that our entry and exit equations satisfy the usual errorcorrection conditions. We also find that a one-time positive shock to entry or profits has a small but permanent positive effect on both the number of firms and total industry profits

    Vale of York 3-D borehole interpretation and cross-sections study

    Get PDF
    The Vale of York between Doncaster and Scunthorpe in the south and York and Bugthorpe in the north is largely underlain by bedrock of the Sherwood Sandstone Group – one of the regions principal aquifers. Significant superficial deposits of Quaternary age overlie the Sherwood Sandstone. This study aims to investigate the nature of these superficial deposits with respect to their relationship with the underlying aquifer. The Vale of York project area represents a varied glaciated terrain, consisting of pro-glacial finegrained sediments, coarser glaciofluvilal sediments and extensive glacial tills. These diverse superficial units vary in thickness throughout the project area. The hydrogeological nature of the natural superficial sequence is consequently highly variable. Units may be considered as aquitards, while others may act as aquifers, providing a potential pathway to the underlying sandstone. The classification of lithologies as aquifer or aquitard is described in detail in this report. To investigate the hydrogeological nature of the superficial sequence, six east-west and three north-south lithostratigraphical cross-sections were constructed. A range of geoscientific information was considered, including existing geological mapping and over 3000 fully attributed and coded boreholes. The cross-sections show a subdivision of the superficial sequence into lithostratigraphical units. Each unit is described in detail in this report. In addition, a series of thematic maps were generated from the lithological component of the digital borehole data. Total superficial aquifer and superficial aquitard maps show how the lithological nature of the superficial sequence varies across the area. Rockhead elevation and superficial thickness maps indicate where the sandstone aquifer outcrops at the ground surface. In summary, four main lithostratigraphical units overlie the Sherwood Sandstone Group aquifer in the project area: a basal sequence of glaciofluvial sand and gravel (interpreted as a superficial aquifer), glaciolacustrine laminated silt & clay (aquitard), glacial till comprising sandy gravelly clay (aquitard), and a cover sequence of fluvial and aeolian sand, clay and peat (aquifer / aquitard). The correlations illustrate that in certain areas, superficial deposits are thin or absent and that in these areas the Sherwood Sandstone aquifer comes directly to ground surface

    Identifying the Irritability Dimension of ODD: Application of a Modified Bifactor Model Across Five Large Community Samples of Children

    Get PDF
    The importance of irritability, as measured among the symptoms of oppositional defiant disorder (ODD), has dramatically come to the fore in recent years. New diagnostic categories rely on the distinct clinical utility of irritability, and models of psychopathology suggest it plays a key role in explaining developmental pathways within and between disorders into adulthood. However, only a few studies have tested multidimensional models of ODD, and the results have been conflicting. Further, consensus has not been reached regarding which symptoms best identify irritability. The present analyses use 5 large community data sets with 5 different measures of parent-reported ODD, comprising 16,280 youth in total, to help resolve these questions. Across the samples, ages ranged from 5 to 18, and included both boys and girls. Confirmatory factor analyses demonstrated that a modified bifactor model showed the best fit in each data set. The structure of the model included 2 correlated specific factors (irritability and oppositional behavior) in addition to a general ODD factor. In 4 models, the best fit was obtained using the items “being touchy,” “angry,” and “often losing temper” as indicators of irritability. Given the structure of the models and the generally high correlation between the specific dimensions, the results suggest that irritability may not be sufficiently distinct from oppositional behavior to support an entirely independent diagnosis. Rather, irritability may be better understood as a dimension of psychopathology that can be distinguished within ODD, and which may be related to particular forms of psychopathology apart from ODD

    Population differentiation and historical demography of the threatened snowy plover Charadrius nivosus (Cassin, 1858)

    Get PDF
    Delineating conservation units is a complex and often controversial process that is particularly challenging for highly vagile species. Here, we reassess population genetic structure and identify those populations of highest conservation value in the threatened snowy plover (Charadrius nivosus, Cassin, 1858), a partial migrant shorebird endemic to the Americas. We use four categories of genetic data—mitochondrial DNA (mtDNA), microsatellites, Z-linked and autosomal single nucleotide polymorphisms (SNPs)—to: (1) assess subspecies delineation and examine population structure (2) compare the sensitivity of the different types of genetic data to detect spatial genetic patterns, and (3) reconstruct demographic history of the populations analysed. Delineation of two traditionally recognised subspecies was broadly supported by all data. In addition, microsatellite and SNPs but not mtDNA supported the recognition of Caribbean snowy plovers (C. n. tenuirostris) and Floridian populations (eastern C. n. nivosus) as distinct genetic lineage and deme, respectively. Low migration rates estimated from autosomal SNPs (m < 0.03) reflect a general paucity of exchange between genetic lineages. In contrast, we detected strong unidirectional migration (m = 0.26) from the western into the eastern nivosus deme. Within western nivosus, we found no genetic differentiation between coastal Pacific and inland populations. The correlation between geographic and genetic distances was weak but significant for all genetic data sets. All demes showed signatures of bottlenecks occurring during the past 1000 years. We conclude that at least four snowy plover conservation units are warranted: in addition to subspecies nivosus and occidentalis, a third unit comprises the Caribbean tenuirostris lineage and a fourth unit the distinct eastern nivosus deme

    Impact of active case finding for tuberculosis with mass chest X-ray screening in Glasgow, Scotland, 1950–1963: an epidemiological analysis of historical data

    Get PDF
    Background Community active case finding (ACF) for tuberculosis was widely implemented in Europe and North America between 1940 and 1970, when incidence was comparable to many present-day high-burden countries. Using an interrupted time series analysis, we analysed the effect of the 1957 Glasgow mass chest X-ray campaign to inform contemporary approaches to screening. Methods and findings Case notifications for 1950 to 1963 were extracted from public health records and linked to demographic data. We fitted Bayesian multilevel regression models to estimate annual relative case notification rates (CNRs) during and after a mass screening intervention implemented over 5 weeks in 1957 compared to the counterfactual scenario where the intervention had not occurred. We additionally estimated case detection ratios and incidence. From 11 March 1957 to 12 April 1957, 714,915 people (622,349 of 819,301 [76.0%] resident adults ≄15 years) were screened with miniature chest X-ray; 2,369 (0.4%) were diagnosed with tuberculosis. Pre-intervention (1950 to 1956), pulmonary CNRs were declining at 2.3% per year from a CNR of 222/100,000 in 1950. With the intervention in 1957, there was a doubling in the pulmonary CNR (RR: 1.95, 95% uncertainty interval [UI] [1.81, 2.11]) and 35% decline in the year after (RR: 0.65, 95% UI [0.59, 0.71]). Post-intervention (1958 to 1963) annual rates of decline (5.4% per year) were greater (RR: 0.77, 95% UI [0.69, 0.85]), and there were an estimated 4,599 (95% UI [3,641, 5,683]) pulmonary case notifications averted due to the intervention. Effects were consistent across all city wards and notifications declined in young children (0 to 5 years) with the intervention. Limitations include the lack of data in historical reports on microbiological testing for tuberculosis, and uncertainty in contributory effects of other contemporaneous interventions including slum clearances, introduction of BCG vaccination programmes, and the ending of postwar food rationing. Conclusions A single, rapid round of mass screening with chest X-ray (probably the largest ever conducted) likely resulted in a major and sustained reduction in tuberculosis case notifications. Synthesis of evidence from other historical tuberculosis screening programmes is needed to confirm findings from Glasgow and to provide insights into ongoing efforts to successfully implement ACF interventions in today’s high tuberculosis burden countries and with new screening tools and technologies

    Dynamic human MutSα–MutLα complexes compact mismatched DNA

    Get PDF
    DNA mismatch repair (MMR) corrects errors that occur during DNA replication. In humans, mutations in the proteins MutSα and MutLα that initiate MMR cause Lynch syndrome, the most common hereditary cancer. MutSα surveilles the DNA, and upon recognition of a replication error it undergoes adenosine triphosphate-dependent conformational changes and recruits MutLα. Subsequently, proliferating cell nuclear antigen (PCNA) activates MutLα to nick the error-containing strand to allow excision and resynthesis. The structure–function properties of these obligate MutSα–MutLα complexes remain mostly unexplored in higher eukaryotes, and models are predominately based on studies of prokaryotic proteins. Here, we utilize atomic force microscopy (AFM) coupled with other methods to reveal time- and concentration-dependent stoichiometries and conformations of assembling human MutSα–MutLα–DNA complexes. We find that they assemble into multimeric complexes comprising three to eight proteins around a mismatch on DNA. On the timescale of a few minutes, these complexes rearrange, folding and compacting the DNA. These observations contrast with dominant models of MMR initiation that envision diffusive MutS–MutL complexes that move away from the mismatch. Our results suggest MutSα localizes MutLα near the mismatch and promotes DNA configurations that could enhance MMR efficiency by facilitating MutLα nicking the DNA at multiple sites around the mismatch. In addition, such complexes may also protect the mismatch region from nucleosome reassembly until repair occurs, and they could potentially remodel adjacent nucleosomes

    Effect of First-Pass Reperfusion on Outcome After Endovascular Treatment for Ischemic Stroke

    Get PDF
    Background First-pass reperfusion (FPR) is associated with favorable outcome after endovascular treatment. It is unknown whether this effect is independent of patient characteristics and whether FPR has better outcomes compared with excellent reperfusion (Expanded Thrombolysis in Cerebral Infarction [eTICI] 2C-3) after multiple-passes reperfusion. We aimed to evaluate the association between FPR and outcome with adjustment for patient, imaging, and treatment characteristics to single out the contribution of FPR. Methods and Results FPR was defined as eTICI 2C-3 after 1 pass. Multivariable regression models were used to investigate characteristics associated with FPR and to investigate the effect of FPR on outcomes. We included 2686 patients of the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry. Factors associated with FPR were as follows: history of hyperlipidemia (adjusted odds ratio [OR], 1.05; 95% CI, 1.01-1.10), middle cerebral artery versus intracranial carotid artery occlusion (adjusted OR, 1.11; 95% CI, 1.06-1.16), and aspiration versus stent thrombectomy (adjusted OR, 1.07; 95% CI, 1.03-1.11). Interventionist experience increased the likelihood of FPR (adjusted OR, 1.03 per 50 patients previously treated; 95% CI, 1.01-1.06). Adjusted for patient, imaging, and treatment characteristics, FPR remained associated with a better 24-hour National Institutes of Health Stroke Scale (NIHSS) score (-37%; 95% CI, -43% to -31%) and a better modified Rankin Scale (mRS) score at 3 months (adjusted common OR, 2.16; 95% CI, 1.83-2.54) compared with no FPR (multiple-passes reperfusion+no excellent reperfusion), and compared with multiple-passes reperfusion alone (24-hour NIHSS score, (-23%; 95% CI, -31% to -14%), and mRS score (adjusted common OR, 1.45; 95% CI, 1.19-1.78)). Conclusions FPR compared with multiple-passes reperfusion is associated with favorable outcome, independently of patient, imaging, and treatment characteristics. Factors associated with FPR were the experience of the interventionist, history of hyperlipidemia, location of occluded artery, and use of an aspiration device compared with stent thrombectomy
    • 

    corecore