3,054 research outputs found

    Studying innovation ecosystems using ecology theory

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    This paper proposes a set of perspectives for studying innovation ecosystems that are based on ecological research. Our perspectives are based on fundamental similarities between natural and business systems. We suggest that innovation ecosystems can be defined as pathways of interlinked business models. Pathways are characterised by the flows they convey not the types of business model that support the flows. These pathways convey material and informational resources, as well as value. Like the nutrient and energy pathways in natural ecosystems. Pathways help to recycle scarce resources such as customer attention and customer-derived information. Business model descriptions are similar to an organism’s genome in that they describe limitations on sensing, acting and understanding. We conceptualise this as the ‘umwelt’; the self-world. These limitations have implications for how firms and customers interact with customers. They have other implications for how firms interact with each other in business model communities and how they accommodate each other. We illustrate and test these ecological perspectives using a case study of a healthcare smartphone app’s ecosystem. We find that our perspectives can be used as novel methods of studying interactions between business models; or to study ecosystem building

    A vision-based system for inspecting painted slates

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    Purpose – This paper describes the development of a novel automated vision system used to detect the visual defects on painted slates. Design/methodology/approach – The vision system that has been developed consists of two major components covering the opto-mechanical and algorithmical aspects of the system. The first component addresses issues including the mechanical implementation and interfacing the inspection system with the development of a fast image processing procedure able to identify visual defects present on the slate surface. Findings – The inspection system was developed on 400 slates to determine the threshold settings that give the best trade-off between no false positive triggers and correct defect identification. The developed system was tested on more than 300 fresh slates and the success rate for correct identification of acceptable and defective slates was 99.32 per cent for defect free slates based on 148 samples and 96.91 per cent for defective slates based on 162 samples. Practical implications – The experimental data indicates that automating the inspection of painted slates can be achieved and installation in a factory is a realistic target. Testing the devised inspection system in a factory-type environment was an important part of the development process as this enabled us to develop the mechanical system and the image processing algorithm able to perform slate inspection in an industrial environment. The overall performance of the system indicates that the proposed solution can be considered as a replacement for the existing manual inspection system. Originality/value – The development of a real-time automated system for inspecting painted slates proved to be a difficult task since the slate surface is dark coloured, glossy, has depth profile non-uniformities and is being transported at high speeds on a conveyor. In order to address these issues, the system described in this paper proposed a number of novel solutions including the illumination set-up and the development of multi-component image-processing inspection algorithm

    Factor analysis of treatment outcomes from a UK specialist addiction service:relationship between the Leeds Dependence Questionnaire, Social Satisfaction Questionnaire and 10-item Clinical Outcomes in Routine Evaluation

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    INTRODUCTION AND AIMS: To examine the relationship between three outcome measures used by a specialist addiction service (UK): the Leeds Dependence Questionnaire (LDQ), the Social Satisfaction Questionnaire (SSQ) and the 10-item Clinical Outcomes in Routine Evaluation (CORE-10). DESIGN AND METHOD: A clinical sample of 715 service user records was extracted from a specialist addiction service (2011) database. The LDQ (dependence), SSQ (social satisfaction) and CORE-10 (psychological distress) were routinely administered at the start of treatment and again between 3 and 12 months post-treatment. A mixed pre/post-treatment dataset of 526 service users was subjected to exploratory factor analysis. Parallel Analysis and the Hull method were used to suggest the most parsimonious factor solution. RESULTS: Exploratory factor analysis with three factors accounted for 66.2% of the total variance but Parallel Analysis supported two factors as sufficient to account for observed correlations among items. In the two-factor solution, LDQ items and nine of the 10 CORE-10 items loaded on the first factor >0.41, and the SSQ items on factor 2 with loadings >0.63. A two dimensional summary appears sufficient and clinically meaningful. DISCUSSION AND CONCLUSIONS: Among specialist addiction service users, social satisfaction appears to be a unique construct of addiction and is not the same as variation due to psychological distress or dependence. Our interpretation of the findings is that dependence is best thought of as a specific psychological condition subsumed under the construct psychological distress. [Fairhurst C, Böhnke JR, Gabe R, Croudace TJ, Tober G, Raistrick D. Factor analysis of treatment outcomes from a UK specialist addiction service: Relationship between the Leeds Dependence Questionnaire, Social Satisfaction Questionnaire and 10-item Clinical Outcomes in Routine Evaluation. Drug Alcohol Rev 2014;33:643–650

    Phasic Firing in Vasopressin Cells: Understanding Its Functional Significance through Computational Models

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    Vasopressin neurons, responding to input generated by osmotic pressure, use an intrinsic mechanism to shift from slow irregular firing to a distinct phasic pattern, consisting of long bursts and silences lasting tens of seconds. With increased input, bursts lengthen, eventually shifting to continuous firing. The phasic activity remains asynchronous across the cells and is not reflected in the population output signal. Here we have used a computational vasopressin neuron model to investigate the functional significance of the phasic firing pattern. We generated a concise model of the synaptic input driven spike firing mechanism that gives a close quantitative match to vasopressin neuron spike activity recorded in vivo, tested against endogenous activity and experimental interventions. The integrate-and-fire based model provides a simple physiological explanation of the phasic firing mechanism involving an activity-dependent slow depolarising afterpotential (DAP) generated by a calcium-inactivated potassium leak current. This is modulated by the slower, opposing, action of activity-dependent dendritic dynorphin release, which inactivates the DAP, the opposing effects generating successive periods of bursting and silence. Model cells are not spontaneously active, but fire when perturbed by random perturbations mimicking synaptic input. We constructed one population of such phasic neurons, and another population of similar cells but which lacked the ability to fire phasically. We then studied how these two populations differed in the way that they encoded changes in afferent inputs. By comparison with the non-phasic population, the phasic population responds linearly to increases in tonic synaptic input. Non-phasic cells respond to transient elevations in synaptic input in a way that strongly depends on background activity levels, phasic cells in a way that is independent of background levels, and show a similar strong linearization of the response. These findings show large differences in information coding between the populations, and apparent functional advantages of asynchronous phasic firing

    A new waist-to-height ratio predicts abdominal adiposity in adults

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    Our aim was to identify the best anthropometric index associated with waist adiposity. The six weight-status indices included body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHTR), and a new waist-by-height0.5 ratio (WHT.5R). The association between three waist skinfolds and the six anthropometric indices was conducted using ANCOVA, MANCOVA, allometric modelling and non-linear regression. The strongest predictors of waist adiposity were (1st) WHT.5R, (2nd) WHTR, (3rd) waist circumference (WC), (4th) BMI, (5th) WHR, and lastly (6th) a body shape index ABSI = WC/(BMI2/3 * height1/2). The allometric and non-linear regression analyses identified the optimal waist-to-height ratio associated with waist adiposity to be (waist * height -0.6). The 95% confidence intervals of the height exponents encompassed -0.5 but excluded -1.0 assumed by WHTR. Assuming that excess waist adiposity is an important cardiovascular risk factor, we recommend that the new WHT.5R be used to advise people how to maintain a “healthy” weight

    Quantifying invasion risk: the relationship between establishment probability and founding population size

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    1. Invasive species usually start out as small colonizing populations that are prone to extinction through demographic stochasticity and Allee effects, leading to a positive relationship between establishment probability and founding population size. However, establishment success also depends on the environment to which species are introduced: for a given species, some locations will be more favourable for establishment than others.2. We present equations for modelling the expected relationship between establishment probability and founding population size when demographic stochasticity, Allee effects and, for the first time, environmental heterogeneity are operating.3. We show that heterogeneity in environmental conditions can change the shape of the relationship between establishment probability and founding population size through a disproportionate decline in the probability of establishment in larger populations, the opposite of an Allee effect. This outcome is likely in most empirical data sets relating founding population size to establishment probability, and highlights that unfavourable environments are often the major cause of establishment failures. It also emphasizes the insights that can be gained from applying models with a theoretical underpinning

    Virginia High Schools: Academic and Social Climate Performance Measures and Black Public Secondary School Administrators

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    Data have consistently revealed a major problem with disproportionality in several academic and social climate measures for African American students compared to their White counterparts. Black students tend to have lower end-of-course (EOC) testing scores in mathematics and reading, a greater tendency to be suspended from school, lower average on-time graduation rates, and higher rates of absenteeism. The current investigative study examined the role of same race administrators and performance indicators among African American students. The findings demonstrated that significant differences between Black and White students existed in end-of-course testing in reading and math. The research also indicated significant relationships between race, school suspension, and attendance in schools with a Black administrative presence. Further qualitative and quantitative research investigating the variables that significantly indicate academic and social climate performance improvements, particularly among marginalized student groups, could be beneficial to students and education leaders alike. Data from this research study showed that student economic status predicted academic and social climate performance between Black and White students, regardless of the race of administrators. However, Black students in non-impoverished settings with a Black administrative presence outperformed their White counterparts in academic and social climate measures. This study could be a precursor to more expansive research on the ways in which improving economic conditions could improve Black student performance, especially with a more diverse administrative school presence

    Accredited qualifications for capacity development in disaster risk reduction and climate change adaptation

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    Increasingly practitioners and policy makers working across the globe are recognising the importance of bringing together disaster risk reduction and climate change adaptation. From studies across 15 Pacific island nations, a key barrier to improving national resilience to disaster risks and climate change impacts has been identified as a lack of capacity and expertise resulting from the absence of sustainable accredited and quality assured formal training programmes in the disaster risk reduction and climate change adaptation sectors. In the 2016 UNISDR Science and Technology Conference on the Implementation of the Sendai Framework for Disaster Risk Reduction 2015–2030, it was raised that most of the training material available are not reviewed either through a peer-to-peer mechanism or by the scientific community and are, thus, not following quality assurance standards. In response to these identified barriers, this paper focuses on a call for accredited formal qualifications for capacity development identified in the 2015 United Nations landmark agreements in DRR and CCA and uses the Pacific Islands Region of where this is now being implemented with the launch of the Pacific Regional Federation of Resilience Professionals, for DRR and CCA. A key issue is providing an accreditation and quality assurance mechanism that is shared across boundaries. This paper argues that by using the United Nations landmark agreements of 2015, support for a regionally accredited capacity development that ensures all countries can produce, access and effectively use scientific information for disaster risk reduction and climate change adaptation. The newly launched Pacific Regional Federation of Resilience Professionals who work in disaster risk reduction and climate change adaptation may offer a model that can be used more widely
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