97 research outputs found
Force transmission in migrating cells
No full textDuring cell migration, forces generated by the actin cytoskeleton are transmitted through adhesion complexes to the substrate. To investigate the mechanism of force generation and transmission, we analyzed the relationship between actin network velocity and traction forces at the substrate in a model system of persistently migrating fish epidermal keratocytes. Front and lateral sides of the cell exhibited much stronger coupling between actin motion and traction forces than the trailing cell body. Further analysis of the traction - velocity relationship suggested that the force transmission mechanisms were different in different cell regions: at the front, traction was generated by a gripping of the actin network to the substrate, whereas at the sides and back, it was produced by the network's slipping over the substrate. Treatment with inhibitors of the actin - myosin system demonstrated that the cell body translocation could be powered by either of the two different processes, actomyosin contraction or actin assembly, with the former associated with significantly larger traction forces than the latter. © 2010 Fournier et al.LC
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The Impact of Cloud Based Supply Chain Management on Supply Chain Resilience
No full textOn March 2011 a destructive 9.0-magnitude earthquake and tsunami along with nuclear explosions struck northeastern Japan; killing thousands of people, halting industry and crippling infrastructure. A large manufacturing company operating outside of Japan received the news in the middle of the night. Within a few hours of the tsunami hitting Japan, this manufacturer’s logistics team ran global materials management reports to communicate the precise status of the products originating from Japan to their entire global network of facilities. With this quick and far reaching communication the manufacturer was able to launch a successful contingency plan. Alternative suppliers, already existing as part of their global network, were evaluated and used to mitigate Japan’s disruptive impact. The resiliency of this manufacturer’s trusted network of supply chain trading partners allowed for minimum disruptions, saving countless money and maintaining continuity for its end-to-end supply chain. This manufacturer was part of a cloud-based supply chain that provided the catalyst to quickly shift its resources to allay the impact of no longer being able to receive product from Japan. Today's supply chains are global and complex networks of enterprises that aim to deliver products in the right quantity, in the right place, and at the right time in an increasingly volatile and unpredictable environment. To cope with internal and external supply chain instability and disruptions, supply chains need to be resilient to survive. A supply chain's ability to collaboratively share information with its supply chain partners is one of the most important factors that enhance a supply chain’s resilience. Cloud based supply chain management (SCM) creates a platform that enables collaborative information sharing that helps to identify, monitor and reduce supply chain risks, vulnerabilities and disruptions. However, supply chain academics and practitioners are at its infancy in understanding the capabilities of cloud based supply chains and its impact on resiliency. The goal of this dissertation is to explore how cloud based SCM make supply chains more resilient to disruptions. To achieve this goal the present research addresses the following fundamental research question: What is the impact of cloud based supply chain management (SCM) on supply chain resilience? To address this research question, this dissertation is comprised of three separate but interrelated essays. The first essay uses the systematically literature review (SLR) method to provide clear definitions of supporting constructs of supply chain resiliency (SCRES), classify the capabilities of SCRES, and identify existing research gaps and future SCRES research ideas. The second essay applies resource-based view (RBV) and dynamic capabilities as the theoretical lens to investigate the role of cloud based SCM in establishing SCRES. The second essay develops a theory-driven, conceptual model to illustrate and explain the relationships among cloud based SCM, SCRES, and the supply chain capabilities identified in the first essay. The third essay uses systems dynamics theory to develop two novel casual loop diagrams (CLD) and its equivalent systems dynamics (SD) models to quantitatively analyze the impact of cloud based information sharing on supply chain performance. A hospital supply chain is used as an illustrative example to show the positive impact on performance. Lead-time, inventory spend, and customer service levels are the comparative performance metrics used in this essay and are consistent with the findings of essays 1 and 2. One CLD and its equivalent SD model represent a traditional on-premise hospital supply chain information sharing platform and the other represent a cloud based hospital information sharing platform. The SD models simulate and compare the performance of the traditional and cloud based hospital supply chain platforms
Is automatic imitation a specialized form of stimulus–response compatibility? Dissociating imitative and spatial compatibilities
No full textIn recent years research on automatic imitation has received considerable attention because it represents an experimental platform for investigating a number of inter-related theories suggesting that the perception of action automatically activates corresponding motor programs. A key debate within this research centers on whether automatic imitation is any different than other long-term S-R associations, such as spatial stimulus-response compatibility. One approach to resolving this issue is to examine whether automatic imitation shows similar response characteristics as other classes of stimulus-response compatibility. This hypothesis was tested by comparing imitative and spatial compatibility effects with a two alternative forced-choice stimulus-response compatibility paradigm and two tasks: one that involved selecting a response to the stimulus (S-R) and one that involved selecting a response to the opposite stimulus (OS-R), i.e., the one not presented. The stimulus for both tasks was a left or right hand with either the index or middle finger tapping down. Speeded responses were performed with the index or middle finger of the right hand in response to the finger identity or the left-right spatial position of the fingers. Based on previous research and a connectionist model, we predicted standard compatibility effects for both spatial and imitative compatibility in the S-R task, and a reverse compatibility effect for spatial compatibility but not for imitative compatibility in the OS-R task. The results from the mean response times, mean percentage of errors, and response time distributions all converged to support these predictions. A second noteworthy result was that the recoding of the finger identity in the OS-R task required significantly more time than the recoding of the left-right spatial position, but the encoding time for the two stimuli in the S-R task was equivalent. In sum, this evidence suggests that the processing of spatial and imitative compatibility is dissociable with regard to two different processes in dual processing models of stimulus-response compatibility
Globalization of Higher Education: Transformation of Higher Education Institutions Through the Process of Internationalization
No full textGlobalization’s impact on higher education institutions in the United States, along with universities around the world, has been unprecedented. Internationalization—the process of infusing, implementing, and integrating an international dimension to the primary functions of higher education institutions—has been the general response. But internationalization is a dynamic and complex phenomenon, tempting some universities and colleges to recoil into their parochial cocoon. Institutions that have chosen this path of educational devolution have felt, are feeling, or will feel the consequences of an uncharted territory.
This study analyzed internationalization within institutions that transformed from having an inward focus to an outward focus. Case studies were conducted at Stanford University, Kalamazoo College, and Troy University to examine institutional transformation through the process of internationalization
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A Multi-Methodology Study of the Historic Impact of Soft Systems Methodology and Its Associated Data Visualization Approach in the Context of Operations and Business Strategy
No full textThe purpose of this three-essay dissertation was to expand knowledge and theory regarding soft systems methodologies (SSMs) and data visualization approaches in business, engineering, and other social sciences. The first essay depicts a bibliometric analysis study of the historic impacts of SSM from 1980-2018 on business, engineering, and other social sciences fields. This study found 285 articles that described or employed SSM for research and included outcomes such as top SSM authors, author citation impacts, common dissemination outlets, time-bound distribution of publications, and other relevant findings. This study provided a picture of who, what, why, when, and where SSM has had the greatest impact on academic thought and practice. The second essay presents research on the academic impact of Systemigrams, an associated data visualization approach, finding examples of conceptual or research development that employed Systemigrams to depict complex problem situations. Recommendations for improvement of designing these data visualizations to increase their field use resulted from this study. The final essay leverages a selection of the articles as use cases to produce a grounded theory study to identify phenomena that arose from the use of SSM for operations and firm strategy research. This study identified two broad themes including (i) scope, structure, and process challenges and (ii) performance and evaluation limitations. These themes were explained by six patterns that emerged from the publications. Each produced change recommendations for SSM process, practice, and reporting to support its continued viability and adoption in business and operations research
Enhancement of signal-to-noise ratio in Brillouin optical time domain analyzers by dual-probe detection
No full textWe demonstrate a simple technique to enhance the signal-to-noise ratio (SNR) in Brillouin optical time-domain analysis sensors by the addition of gain and loss processes. The technique is based on the shift of the pump pulse optical frequency in a double-sideband probe system, so that the gain and loss processes take place at different frequencies. In this manner, the loss and the gain do not cancel each other out, and it makes possible to take advantage of both informations at the same time, obtaining an improvement of 3 dB on the SNR. Furthermore, the technique does not need an optical filtering, so that larger improvement on SNR and a simplification of the setup are obtained. The method is experimentally demonstrated in a 101 km fiber spool, obtaining a measurement uncertainty of 2.6 MHz (2σ) at the worst-contrast position for 2 m spatial resolution. This leads, to the best of our knowledge, to the highest figure-of-merit in a BOTDA without using coding or raman amplification.The authors wish to acknowledge the financial support of the Spanish Ministerio de Economía y Competitividad
through the projects TEC2013-47264- C2-2-R and TEC2016-76021-C2-1-R, FEDER funds and the Universidad Pública de Navarra
Dynamic updating of distributed neural representations using forward models
No full textIn this paper, we present a continuous attractor network model that we hypothesize will give some suggestion of the mechanisms underlying several neural processes such as velocity tuning to visual stimulus, sensory discrimination, sensorimotor transformations, motor control, motor imagery, and imitation. All of these processes share the fundamental characteristic of having to deal with the dynamic integration of motor and sensory variables in order to achieve accurate sensory prediction and/or discrimination. Such principles have already been described in the literature by other high-level modeling studies (Decety and Sommerville in Trends Cogn Sci 7:527-533, 2003; Oztop etal. in Neural Netw 19(3):254-271, 2006; Wolpert etal. in Philos Trans R Soc 358:593-602, 2003). With respect to these studies, our work is more concerned with biologically plausible neural dynamics at a population level. Indeed, we show that a relatively simple extension of the classical neural field models can endow these networks with additional dynamic properties for updating their internal representation using external commands. Moreover, an analysis of the interactions between our model and external inputs also shows interesting properties, which we argue are relevant for a better understanding of the neural processes of the brai
The Influence of Organizational Values on Profitability
No full textOrganizational values have received increased attention in the literature. Research suggested that a relationship existed between organizational values and organizational performance (Alexander & Nagel, 1996; Cascio, 2006; Dobni, Ritchie, & Zerbe, 2000; Hitt, Hoskisson & Harrison, 1991; Van Beurden & Gossling, 2008; Wilkins & Ouchi, 1983; Wolfe, Parker, & Napier, 1994). Despite this belief and the increased attention organizational values have received in the literature, little empirical work has been directed at exploring specifically how this relationship is accomplished.
Pearson’s r product-moment correlations and HLM analyses were used to test the hypotheses and research questions in this study. Partial support was found for several hypotheses. Specifically, support was found for the relationship between values-based business practices and the level of companies’ reported organizational values for several values studied. The strongest support was found for hypothesis 4, which examined the relationship between organizational identity and several dimensions of employee behavior. Surprisingly, overall findings provided little support for the hypotheses and research questions studied. Despite several significant findings, due to the reliability issues with the scales and a small sample size, study findings should be interpreted with caution.
In general, the findings of this study can be used to facilitate the discussion on organizational values and organizational profitability. Specifically, additional research can further the discussion on the relationship between organizational values and organizational profitability. Future research can examine the intermediate factors that should be present to ensure organizational values are implemented in the organization, thus creating an opportunity for organizational values to influence organizational profitability. Implications of this study and future research are discussed
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