141 research outputs found

    Rethinking Invention: Cognition and the Economics of Technological Creativity

    Get PDF
    Economists have typically not devoted much attention to the act of invention. This paper attempts to redress this situation by exploring a form of cognition, analogical transfer, which is thought by some researchers to lie at the heart of successful creativity. An analogical transfer is said to have occurred when information and experiences from one known situation is retrieved and utilized in the search for the solution to an entirely different situation. This paper shows how such analogical thought can give rise to a theoretical framework, in which disparate factors pertaining to technological creativity can be pieced together to yield an explanation of the level of inventive output experienced.invention, technological change, technological creativity, problem solving, learning.

    COMPLACENT OR COMPETITIVE? BRITISH EXPORTERS AND THE DRIFT TO EMPIRE

    Get PDF
    The belief that Britain’s empire markets were soft is well entrenched in the literature. It is, however, a belief that has been largely untested. Indeed, the literature does not even offer an explicit definition of softness. This paper attempts to fill this gap by discussing the meaning of the term and, then, posing the question whether between 1870 and 1914 Britain’s fastest growing markets – Australasia and Canada – can in fact be reasonably labelled soft, as has often been assumed. The paper concludes that the demand for British imports in these markets were driven more by income and price considerations than by colonial sentiment or preference.Empire markets, soft markets, British exports, imperial sentiments

    A systematic model to predict transcriptional regulatory mechanisms based on overrepresentation of transcription factor binding profiles

    Get PDF
    An important aspect of understanding a biological pathway is to delineate the transcriptional regulatory mechanisms of the genes involved. Two important tasks are often encountered when studying transcription regulation, i.e., (1) the identification of common transcriptional regulators of a set of coexpressed genes; (2) the identification of genes that are regulated by one or several transcription factors. In this study, a systematic and statistical approach was taken to accomplish these tasks by establishing an integrated model considering all of the promoters and characterized transcription factors (TFs) in the genome. A promoter analysis pipeline (PAP) was developed to implement this approach. PAP was tested using coregulated gene clusters collected from the literature. In most test cases, PAP identified the transcription regulators of the input genes accurately. When compared with chromatin immunoprecipitation experiment data, PAP's predictions are consistent with the experimental observations. When PAP was used to analyze one published expression-profiling data set and two novel coregulated gene sets, PAP was able to generate biologically meaningful hypotheses. Therefore, by taking a systematic approach of considering all promoters and characterized TFs in our model, we were able to make more reliable predictions about the regulation of gene expression in mammalian organisms

    Phenotypic screening, transcriptional profiling, and comparative genomic analysis of an invasive and non-invasive strain of Candida albicans

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Invasion of host tissue by the human fungal pathogen <it>Candida albicans </it>is an important step during the development of candidosis. However, not all <it>C. albicans </it>strains possess the same invasive and virulence properties. For example, the two clinical isolates SC5314 and ATCC10231 differ in their ability to invade host tissue and cause experimental infections. Strain SC5314 is invasive whereas strain ATCC10231 is non-invasive and strongly attenuated in virulence compared to SC5314. In this study we compare the <it>in vitro </it>phenotypic, transcriptional and genomic profiles of these two widely used laboratory strains in order to determine the principal biological and genetic properties responsible for their differential virulence.</p> <p>Results</p> <p>In all media tested, the two strains showed the same metabolic flexibility, stress resistance, adhesion properties and hydrolytic enzyme secretion <it>in vitro</it>. However, differences were observed in response to cell-surface disturbing agents and alkaline pH. Furthermore, reduced hyphal formation in strain ATCC10231 under certain conditions correlated with reduced invasive properties in an <it>in vitro </it>invasion assay and a reduced ability to invade epithelial tissue. Despite these diverse phenotypic properties, no substantial genomic differences were detected by comparative genome hybridisation within the open reading frames. However, <it>in vitro </it>transcriptional profiling displayed major differences in the gene expression of these two strains, even under normal <it>in vitro </it>growth conditions.</p> <p>Conclusion</p> <p>Our data suggest that the reason for differential virulence of <it>C. albicans </it>strains is not due to the absence of specific genes, but rather due to differences in the expression, function or activity of common genes.</p

    Legally Irrelevant Factors in Judicial Decision-making: Battle Deaths and the Imposition of the Death Penalty in Nazi Germany

    Get PDF
    We study the effect of legally irrelevant events on the sentencing outcomes of around 2,500 individual defendants, heard before the People's Court in Nazi Germany. Our analysis exploits exogeneous variation in battle deaths and estimates their effect on the likelihood of receiving the death penalty. According to our results, higher German fatalities on the battlefield systematically increased the chances of receiving the death penalty. We show that decisions by experienced judges were less affected by battle deaths, while judges who were more ideologically committed to the regime were more likely to impose the death penalty in response to hearing news of higher German fatalities. Our results are not driven by particular types of offenses or defendants, time periods, or changes in arrest patterns and are robust to the use of major bombing raids of German cities instead of battle deaths. We also find some evidence that victories of the German national soccer team decreased the chances of capital punishment

    DESIGN AND DEVELOPMENT OF A BROILER MORTALITY REMOVAL ROBOT

    Get PDF
    Manual collection of broiler mortality is time-consuming, unpleasant, and laborious. The objectives of this research were: (1) to design and fabricate a broiler mortality removal robot from commercially available components to automatically collect dead birds; (2) to compare and evaluate deep learning models and image processing algorithms for detecting and locating dead birds; and (3) to examine detection and mortality pickup performance of the robot under different light intensities. The robot consisted of a two-finger gripper, a robot arm, a camera mounted on the robot’s arm, and a computer controller. The robot arm was mounted on a table, and 64 Ross 708 broilers between 7 and 14 days of age were used for the robot development and evaluation. The broiler shank was the target anatomical part for detection and mortality pickup. Deep learning models and image processing algorithms were embedded into the vision system and provided location and orientation of the shank of interest, so that the gripper could approach and position itself for precise pickup. Light intensities of 10, 20, 30, 40, 50, 60, 70, and 1000 lux were evaluated. Results indicated that the deep learning model “You Only Look Once (YOLO)” V4 was able to detect and locate shanks more accurately and efficiently than YOLO V3. Higher light intensities improved the performance of the deep learning model detection, image processing orientation identification, and final pickup performance. The final success rate for picking up dead birds was 90.0% at the 1000-lux light intensity. In conclusion, the developed system is a helpful tool towards automating broiler mortality removal from commercial housing, and contributes to further development of an integrated autonomous set of solutions to improve production and resource use efficiency in commercial broiler production, as well as to improve well-being of workers

    Legally Irrelevant Factors in Judicial Decision-making: Battle Deaths and the Imposition of the Death Penalty in Nazi Germany

    Get PDF
    We study the effect of legally irrelevant events on the sentencing outcomes of around 2,500 individual defendants, heard before the People's Court in Nazi Germany. Our analysis exploits exogeneous variation in battle deaths and estimates their effect on the likelihood of receiving the death penalty. According to our results, higher German fatalities on the battlefield systematically increased the chances of receiving the death penalty. We show that decisions by experienced judges were less affected by battle deaths, while judges who were more ideologically committed to the regime were more likely to impose the death penalty in response to hearing news of higher German fatalities. Our results are not driven by particular types of offenses or defendants, time periods, or changes in arrest patterns and are robust to the use of major bombing raids of German cities instead of battle deaths. We also find some evidence that victories of the German national soccer team decreased the chances of capital punishment

    The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

    Get PDF
    Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care
    • 

    corecore