677 research outputs found

    On predictive entrepreneurial action in uncertain, ill-structured conditions

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    Decision-making is at the heart of entrepreneurship. Unsurprisingly, entrepreneurship research has engaged with processes of entrepreneurial decision-making resulting, most importantly, in the notions of causation, effectuation, and enactment. Nevertheless, the range of processes delineated to date remains somewhat incomplete. Drawing on crucial insights from the analysis of decision problem structures reveals that entrepreneurship theory has lacked a process that both recognizes the ill-structuredness typically surrounding entrepreneurial decisions and places prognoses center stage. While effectuation implicitly addresses structural defects but denies prognoses a central role, causation emphasizes the importance of predictions while being associated with well-structured, risky environments, and thus, unaffected by structural defects. Theorizing about a combination thereof, that is, a process recognizing and considering the ill-structuredness of entrepreneurial environments yet building on predictions of the future is overdue. This paper, therefore, seeks to foster a more comprehensive yet nuanced understanding of entrepreneurial decision-making processes by outlining the intrinsic features of one such process that we term execution and relating it to existing processes

    From Knightian uncertainty to real‐structuredness: Further opening the judgment black box

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    Research Summary: Entrepreneurial judgment remains a concept that resembles a black box. This article attempts to further open that black box by developing a dimensionalization of types of judgment. To achieve this, it joins recent efforts to explicitly link entrepreneurship to Simonian themes by integrating the notion of decision problem structures into the judgment-based approach (JBA) to entrepreneurship. This article proposes a more comprehensive and nuanced approach to judgment in the face of decision problems we label “realstructured.” Extending the JBA comes with several important implications: It uncovers additional entrepreneurial knowledge problems, provides new insights for both economic organization and judgment communicability, and informs research on entrepreneurial success and failure. It also sheds new light on the controversy over the relationship between effectuation and judgment. Managerial Summary: When taking decisions, entrepreneurs cannot know how the future will pan out. Those decisions are made under conditions of uncertainty and only time will tell whether they prove astute or otherwise. The uncertainty of the future leads entrepreneurs to exercise judgment based on their individual beliefs and to act accordingly. The components of that entrepreneurial judgment remain rather underexplored. The purpose of this article is to dig deeper into, and thereby improve, the understanding of entrepreneurial judgment. The main result of this article is a four-part dimensionalization of judgment, covering entrepreneurial (sub-)judgments on the effects incurred by action, the appraisal of action alternatives, the goals underlying action, and resolving the decision problem

    Theory and Phenomenology of Vector Mesons in Medium

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    Electromagnetic probes promise to be direct messengers of (spectral properties of) hot and dense matter formed in heavy-ion collisions, even at soft momentum transfers essential for characterizing possible phase transitions. We examine how far we have progressed toward this goal by highlighting recent developments, and trying to establish connections between lattice QCD, effective hadronic models and phenomenology of dilepton production.Comment: 8 pages latex incl. 12 ps/eps files; invited plenary talk at Quark Matter 2006 conference, Shanghai (China), Nov. 14-20, 200

    Management of an Accessory Bile Duct Leak Following Pancreaticoduodenectomy: A Novel Approach Utilizing a Percutaneous and Endoscopic Rendezvous.

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    Biliary leaks are uncommon but morbid complications of pancreaticoduodenectomies, which have historically been managed with percutaneous drainage, reoperation, or a combination of both. We report a de novo percutaneous-endoscopic hepaticojejunostomy from an anomalous right hepatic duct injured during pancreaticoduodenectomy to the afferent bowel limb. The percutaneous-endoscopic hepaticojejunostomy was stented to allow for tract formation with successful stent removal after 5.5 months. One year after the creation of the percutaneous-endoscopic hepaticojejunostomy, the patient remains clinically well without evidence of biliary leak or obstruction

    Anhydrous Liquid Line of Descent of Yamato 980459 and Evolution of Martian Parental Magmas

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    Martian basalts represented by the shergottite meteorites reflect derivation from highly depleted mantle sources (high Nd, strong LREE depletions, low fO2)[1-3], with evidence of mixing with a much more enriched and oxidized reservoir, most likely a late-stage product of crystallization of an initial martian magma ocean [3-6]. The martian basaltic meteorites Yamato 980459 (Y98) and QUE 94201 (QUE) have bulk compositions that appear to represent bonafide liquids, rather than products of protracted crystallization. These two meteorites also represent the most primitive and evolved examples of the depleted basaltic shergottite suite. Magmatic liquids serve as effective probes of their source regions, and thus studying the potential relationship between magmas represented by Y98 and QUE can yield important information on the formation and evolution of martian basalts. Although the ages of these meteorites preclude that they are petrogenetically related to each other, they represent the best existing candidates for genuine liquids (other meteorites are suggested to represent liquid compositions, including LAR 06319 [7] and NWA 5789 [8], but only Y98 and QUE have been verified experimentally). They span much of the bulk-compositional range of martian basaltic meteorites, and represent end-member liquid compositions likely to arise from partial melting of the martian mantle. Recent efforts to model Y98-like parent liquid evolution by fractional crystallization using MELTS [6] produced a derivative liquid composition that closely matches QUE bulk composition, although it required a some-what unusual crystallization sequence. Experimental endeavours to verify this result at 1 bar have, however, been inconclusive [9]

    Transcriptome Analysis of Targeted Mouse Mutations Reveals the Topography of Local Changes in Gene Expression.

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    The unintended consequences of gene targeting in mouse models have not been thoroughly studied and a more systematic analysis is needed to understand the frequency and characteristics of off-target effects. Using RNA-seq, we evaluated targeted and neighboring gene expression in tissues from 44 homozygous mutants compared with C57BL/6N control mice. Two allele types were evaluated: 15 targeted trap mutations (TRAP); and 29 deletion alleles (DEL), usually a deletion between the translational start and the 3' UTR. Both targeting strategies insert a bacterial beta-galactosidase reporter (LacZ) and a neomycin resistance selection cassette. Evaluating transcription of genes in +/- 500 kb of flanking DNA around the targeted gene, we found up-regulated genes more frequently around DEL compared with TRAP alleles, however the frequency of alleles with local down-regulated genes flanking DEL and TRAP targets was similar. Down-regulated genes around both DEL and TRAP targets were found at a higher frequency than expected from a genome-wide survey. However, only around DEL targets were up-regulated genes found with a significantly higher frequency compared with genome-wide sampling. Transcriptome analysis confirms targeting in 97% of DEL alleles, but in only 47% of TRAP alleles probably due to non-functional splice variants, and some splicing around the gene trap. Local effects on gene expression are likely due to a number of factors including compensatory regulation, loss or disruption of intragenic regulatory elements, the exogenous promoter in the neo selection cassette, removal of insulating DNA in the DEL mutants, and local silencing due to disruption of normal chromatin organization or presence of exogenous DNA. An understanding of local position effects is important for understanding and interpreting any phenotype attributed to targeted gene mutations, or to spontaneous indels

    Editorial : The psychology of fake news on social media, who falls for it, who shares it, why, and can we help users detect it?

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    The proliferation of fake news on social media has become a major societal concern which has been shown to impact elections, referenda, and effective public health messaging (Lewandowsky et al., 2017). To combat this, there is now a growing body of research that focuses on the role of psychological and behavioural science in understanding and mitigating the spread of misinformation (Rapp & Salovich, 2018;Van Bavel et al., 2020). For example, research on belief revision has reported a 'continued influence effect' (CIE) where misinformation lingers in the mind of a person despite being categorically refuted (e.g., Ecker et al., 2010;Desai et al., 2020), simulations have attempted to replicate the seepage of misinformation in social networks (Lewandowsky et al., 2019), and inoculation theorists are building training tools to understand and enhance psychological resistance against misinformation. Such attempts have been conducted in the context of COVID-19 (Basol et al., 2021), political disinformation (Roozenbeek & van der Linden, 2020), and climate change (Maertens et al., 2020). While it is clear that important advances have been made in our understanding of the critical psychological functions that underpin how individuals seek out, process, and share misinformation -there is still much to do. Therefore, in this special topic, we are delighted to introduce six new papers which present novel, interesting, and engaging contributions to our understanding of the fake news phenomenon

    Pressures to Publish: Catalysts for the Loss of Scientific Writing Integrity?

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    Publishing research is the final step in the scientific process and is used as the primary means for disseminating research findings to the scientific community. Publishing can embody many personal motivations (e.g., gratification, seeing a finished product in print, desire to further science) for authors as well as professional benefits (e.g., promotion, tenure, future funding opportunities). As the scientific workforce and competition for jobs and funding increase, publishing productivity has become a driving factor for many authors, which may lead to writing practices that violate integrity. In this essay, we discuss writing actions that may be considered a violation of integrity in the context of traditional manuscript sections (introduction and discussion, methods, and results). We define “integrity” as consistency of actions that reflect honesty and truthfulness. Writing the introduction and discussion can be compared to an artistic creation because the rendition of the data may vary depending on the intentions and experience of the author. Some authors may be tempted to relate their research to a hot topic (e.g., climate change, model selection) in an attempt to increase publication success or maximize visibility in search engines, despite not having sufficient data to support their conclusions. Caution must be taken to not overextend the “story” beyond the bounds of the data. Modification of the methods and results sections contains the most extreme cases of scientific integrity violations (e.g., changing an alpha level, only presenting positive results, running numerous tests until desired outcome). Manipulation of methods or results is more difficult to detect by peer review. We believe that however destructive integrity violations may be, despite benefits to the author (e.g., accolades, publication, potential citations, promotion, etc.), the individual scientist should hold him- or herself accountable and to a high standard to avoid sacrificing integrity. Presión para publicar: catalizadores de la pérdida de integridad en la publicación científica Resume: La publicación es la etapa final del proceso científico y se utiliza como el medio principal para diseminar los hallazgos de una investigación. Para los autores, publicar puede implicar distintas motivaciones tanto personales (p.e. satisfacción, ver un producto final impreso, deseo de hacer más ciencia) como profesionales (p.e. promoción interna, basificación, oportunidades de financiamiento). A medida que se incrementa la fuerza laboral científica y la competencia por trabajo y financiamiento, la productividad en cuanto a las publicaciones se ha convertido en un factor determinante para muchos autores, lo cual puede dar pie a prácticas de publicación que comprometen la integridad. En este ensayo se discuten aquellas prácticas de publicación que se considera que comprometen la integridad en el contexto de las secciones habituales que conforman un artículo (introducción y discusión, métodos y resultados). Se define la integridad como la consistencia en acciones que reflejan honestidad y veracidad. Escribir la introducción y discusión se compara con una creación artística en cuanto a que la interpretación de los datos puede variar dependiendo de las intenciones y experiencia del autor. Algunos autores pueden estar tentados a relacionar su investigación a un tópico de actualidad (p.e. cambio climático, selección de modelos) en un intento por incrementar el éxito de la publicación y maximizar la posibilidad de ser encontrados mediante motores de búsqueda, a pesar de que no cuentan con suficientes datos como para apoyar sus conclusiones. Se debe tener cuidado para no extender la historia más allá de los límites que establecen los datos. La modificación de las secciones de métodos y resultados implica los casos más extremos de violaciones a la integridad (p.e. cambiar el nivel de alfa, presentar sólo resultados positivos, realizar numerosas pruebas hasta que salga el resultado esperado). La manipulación de los métodos o los resultados resulta particularmente difícil de detectar durante el proceso de revisión por pares. Creemos que no obstante lo destructivas que puedan ser las violaciones a la integridad y a pesar de los beneficios que obtengan los autores (p.e. premios, potencial de citación, promociones, etc.), el individuo científico debe mantener su sentido de responsabilidad y sus estándares en alto con el fin de evitar sacrificar su integridad

    Report of the panel on geopotential fields: Gravity field, section 8

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    The objective of the Geopotential Panel was to develop a program of data acquisition and model development for the Earth's gravity and magnetic fields that meet the basic science requirements of the solid Earth and ocean studies. Presented here are the requirements for gravity information and models through the end of the century, the present status of our knowledge, data acquisition techniques, and an outline of a program to meet the requirements

    Analysis and Control of Chain Mobility in Protein Hydrogels

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    Coiled-coil domains can direct the assembly of protein block copolymers into physically cross-linked, viscoelastic hydrogels. Here, we describe the use of fluorescence recovery after photobleaching (FRAP) to probe chain mobility in reversible hydrogels assembled from engineered proteins bearing terminal coiled-coil domains. We show that chain mobility can be related to the underlying dynamics of the coiled-coil domains by application of a three-state “hopping” model of chain migration. We further show that genetic programming allows the effective mobility of network chains to be varied 500-fold through modest changes in protein sequence. Destabilization of the coiled-coil domains by site-directed mutagenesis increases the effective diffusivity of probe chains. Conversely, probe mobility is reduced by expanding the hydrophobic surface area of the coiled-coil domains through introduction of the bulky leucine surrogate homoisoleucine. Predictions from the three-state model imply asymmetric sequential binding of the terminal domains. Brownian Dynamics simulations suggest that binding asymmetry is a general feature of reversible gels, arising from a loss in entropy as chains transition to a conformationally restricted bridged state
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