95 research outputs found
Divergent Reactions to Convergent Strategies: Investor Beliefs and Analyst Reactions During Technological Change
An important outcome of technological change is industry âconvergence,â as a new technology spurs competition between established firms from different industries. We study the reactions of securities analysts, as important sources of institutional pressures for firms, to the similar product/market strategies undertaken by firms from different prior industries responding to industry convergence. Our empirical setting is the convergence between the wireline telecommunications and cable television industries in the period following the advent of voice over Internet protocol technology. Controlling for firm financial performance and capabilities, we find that analysts were consistently more positive toward the cable firms than toward the wireline telecom firms. Our findings further show that this divergence in reactions arises from differences in existing investor expectations and preferences concerning how firms create value; stocks owned by investors with a greater preference for growth receive more positive reactions than those owned by investors with a greater preference for margins. However, this divergence in reactions shrinks over time as convergence unfolds and as investors shift their shareholdings in response to misalignment between their preferences and firms\u27 strategic changes. Reactions from analystsâreflecting inertial expectations of investorsâmay persist for a time despite changes to firms\u27 strategies, thus creating challenges for some firms in responding to technological change and industry convergence while legitimating and enabling similar responses from their competitors
An expanded analysis framework for multivariate GWAS connects inflammatory biomarkers to functional variants and disease
Multivariate methods are known to increase the statistical power to detect associations in the case of shared genetic basis between phenotypes. They have, however, lacked essential analytic tools to follow-up and understand the biology underlying these associations. We developed a novel computational workflow for multivariate GWAS follow-up analyses, including fine-mapping and identification of the subset of traits driving associations (driver traits). Many follow-up tools require univariate regression coefficients which are lacking from multivariate results. Our method overcomes this problem by using Canonical Correlation Analysis to turn each multivariate association into its optimal univariate Linear Combination Phenotype (LCP). This enables an LCP-GWAS, which in turn generates the statistics required for follow-up analyses. We implemented our method on 12 highly correlated inflammatory biomarkers in a Finnish population-based study. Altogether, we identified 11 associations, four of which (F5, ABO, C1orf140 and PDGFRB) were not detected by biomarker-specific analyses. Fine-mapping identified 19 signals within the 11 loci and driver trait analysis determined the traits contributing to the associations. A phenome-wide association study on the 19 representative variants from the signals in 176,899 individuals from the FinnGen study revealed 53 disease associations (p <1 x 10(-4)). Several reported pQTLs in the 11 loci provided orthogonal evidence for the biologically relevant functions of the representative variants. Our novel multivariate analysis workflow provides a powerful addition to standard univariate GWAS analyses by enabling multivariate GWAS follow-up and thus promoting the advancement of powerful multivariate methods in genomics.Peer reviewe
Analyzing international medical graduate research productivity for application to US neurosurgery residency and beyond: A survey of applicants, program directors, and institutional experience
BackgroundThe authors investigated perceived discrepancies between the neurosurgical research productivity of international medical graduates (IMGs) and US medical graduates (USMGs) through the perspective of program directors (PDs) and successfully matched IMGs.MethodsResponses to 2 separate surveys on neurosurgical applicant research productivity in 115 neurosurgical programs and their PDs were analyzed. Neurosurgical research participation was analyzed using an IMG survey of residents who matched into neurosurgical residency within the previous 8 years. Productivity of IMGs conducting dedicated research at the study institution was also analyzed.ResultsThirty-two of 115 (28%) PDs responded to the first research productivity survey and 43 (37%) to the second IMG research survey. PDs expected neurosurgery residency applicants to spend a median of 12â24 months on research (Q1-Q3: 0â12 to 12â24; minimum time: 0â24; maximum time: 0â48) and publish a median of 5 articles (Q1-Q3: 2â5 to 5â10; minimum number: 0â10; maximum number: 4â20). Among 43 PDs, 34 (79%) ranked âresearch institution or associated personnelâ as the most important factor when evaluating IMGs' research. Forty-two of 79 (53%) IMGs responding to the IMG-directed survey reported a median of 30 months (Q1-Q3: 18â48; range: 4â72) of neurosurgical research and 12 published articles (Q1-Q3: 6â24; range: 1â80) before beginning neurosurgical residency. Twenty-two PDs (69%) believed IMGs complete more research than USMGs before residency. Of 20 IMGs conducting dedicated neuroscience/neurosurgery research at the study institution, 16 of 18 who applied matched or entered a US neurosurgical training program; 2 applied and entered a US neurosurgical clinical fellowship.ConclusionThe research work of IMGs compared to USMGs who apply to neurosurgery residency exceeds PDs' expectations regarding scientific output and research time. Many PDs perceive IMG research productivity before residency application as superior to USMGs. Although IMGs comprise a small percentage of trainees, they are responsible for a significant amount of US-published neurosurgical literature. Preresidency IMG research periods may be improved with dedicated mentoring and advising beginning before the research period, during the period, and within a neurosurgery research department, providing a formal structure such as a research fellowship or graduate program for IMGs aspiring to train in the US
The interpretation of systematic reviews with meta-analyses: an objective or subjective process?
<p>Abstract</p> <p>Background</p> <p>Discrepancies between the conclusions of different meta-analyses (quantitative syntheses of systematic reviews) are often ascribed to methodological differences. The objective of this study was to determine the discordance in interpretations when meta-analysts are presented with identical data.</p> <p>Methods</p> <p>We searched the literature for all randomized clinical trials (RCT) and review articles on the efficacy of intravenous magnesium in the early post-myocardial infarction period. We organized the articles chronologically and grouped them in packages. The first package included the first RCT, and a summary of the review articles published prior to first RCT. The second package contained the second and third RCT, a meta-analysis based on the data, and a summary of all review articles published prior to the third RCT. Similar packages were created for the 5<sup>th </sup>RCT, 10<sup>th </sup>RCT, 20<sup>th </sup>RCT and 23<sup>rd </sup>RCT (all articles). We presented the packages one at a time to eight different reviewers and asked them to answer three clinical questions after each package based solely on the information provided. The clinical questions included whether 1) they believed magnesium is now proven beneficial, 2) they believed magnesium will eventually be proven to be beneficial, and 3) they would recommend its use at this time.</p> <p>Results</p> <p>There was considerable disagreement among the reviewers for each package, and for each question. The discrepancies increased when the heterogeneity of the data increased. In addition, some reviewers became more sceptical of the effectiveness of magnesium over time, and some reviewers became less sceptical.</p> <p>Conclusion</p> <p>The interpretation of the results of systematic reviews with meta-analyses includes a subjective component that can lead to discordant conclusions that are independent of the methodology used to obtain or analyse the data.</p
The Accumulation of Organic Carbon in Mineral Soils by Afforestation of Abandoned Farmland
The afforestation of abandoned farmland significantly influences soil organic carbon (OC). However, the dynamics between OC inputs after afforestation and the original OC are not well understood. To learn more about soil OC dynamics after afforestation of farmland, we measured the soil OC content in paired forest and farmland plots in Shaanxi Province, China. The forest plots had been established on farmland 18, 24, 48, 100, and 200 yr previously. The natural 13C abundance of soil organic matter was also analyzed to distinguish between crop- and forest-derived C in the afforested soils. We observed a nonlinear accumulation of total OC in the 0â80 cm depth of the mineral soil across time. Total soil OC accumulated more rapidly under forest stands aged 18 to 48 yr than under forest stands aged 100 or 200 yrs. The rate of OC accumulation was also greater in the 0â10 cm depth than in the 10â80 cm depth. Forest-derived OC in afforested soils also accumulated nonlinearly across time, with the greatest increase in the 0â20 cm depth. Forest-derived OC in afforest soils accounted for 52â86% of the total OC in the 0â10 cm depth, 36â61% of the total OC in the 10â20 cm depth, and 11â50% of the total OC in the 20â80 cm depth. Crop-derived OC concentrations in the 0â20 cm depth decreased slightly after afforestation, but there was no change in crop-derived OC concentrations in the 20â80 cm depth. The results of our study support the claim that afforestation of farmland can sequester atmospheric CO2 by increasing soil OC stocks. Changes in the OC stocks of mineral soils after afforestation appear to be influenced mainly by the input of forest-derived C rather than by the loss of original OC
Ambidextrie â der organisationale Drahtseilakt. Synergie zwischen Exploration und Exploitation als Voraussetzung fĂŒr die digitale Transformation
Sich disruptiv verĂ€ndernde Rahmenbedingungen können dazu fĂŒhren, dass bisher erfolgreiche GeschĂ€ftsmodelle innert weniger Jahren obsolet werden. Geschuldet ist dies einer mangelnden AnpassungsfĂ€higkeit, deren Ursache unter anderem in der sogenannten PfadabhĂ€ngigkeit wurzeln kann. Die PfadabhĂ€ngigkeit bezeichnet eine Situation, in der die Auswirkungen von stark durch die Vergangenheit geprĂ€gten Entscheiden dazu fĂŒhren, dass die Möglichkeit bzw. Notwendigkeit neuer GeschĂ€ftsmodelle nicht erkannt, verpasst oder deren Chancen falsch eingeschĂ€tzt werden. Das Ausbrechen aus der PfadabhĂ€ngigkeit ist fĂŒr den Fortbestand von Unternehmen daher von zentraler Bedeutung. Das Konzept der organisationalen Ambidextrie widmet sich dieser Problemstellung. Ambidextrie beschreibt die FĂ€higkeit eines Unternehmens, einerseits das KerngeschĂ€ft stetig weiterzuentwickeln, gleichzeitig aber auch neue Wege und Denkweisen zu etablieren und so sicherzustellen, dass VerĂ€nderungen im Umsystem rechtzeitig erkannt und die sich dadurch bietenden Chancen fĂŒr die Zukunft genutzt werden. Eine FĂ€higkeit, die gerade im Zeitalter der Digitalisierung an Wichtigkeit gewinnt
Garotas de loja, histĂłria social e teoria social [Shop Girls, Social History and Social Theory]
Shop workers, most of them women, have made up a significant proportion of Britainâs labour force since the 1850s but we still know relatively little about their history. This article argues that there has been a systematic neglect of one of the largest sectors of female employment by historians and investigates why this might be. It suggests that this neglect is connected to framings of work that have overlooked the service sector as a whole as well as to a continuing unease with the consumer societyâs transformation of social life. One element of that transformation was the rise of new forms of aesthetic, emotional and sexualised labour. Certain kinds of âshop girlsâ embodied these in spectacular fashion. As a result, they became enduring icons of mass consumption, simultaneously dismissed as passive cultural dupes or punished as powerful agents of cultural destruction. This article interweaves the social history of everyday shop workers with shifting representations of the âshop girlâ, from Victorian music hall parodies, through modernist social theory, to the bizarre bombing of the Biba boutique in London by the Angry Brigade on May Day 1971. It concludes that progressive historians have much to gain by reclaiming these workers and the service economy that they helped create
Seed size variation: magnitude, distribution, and ecological correlates
We examined seed-mass variation in 39 species (46 populations) of plants in eastern-central Illinois, USA. The coefficient of variation of seed mass commonly exceeded 20%. Significant variation in mean seed mass occurred among conspecific plants in most species sampled (by hierarchical ANOVA), averaging 38% of total variance. For most species, within-plant variation was the larger component of total variance, averaging 62% of total variance. Variation in seed mass among fruits within crops was significant in most species tested.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42741/1/10682_2005_Article_BF02067274.pd
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