151 research outputs found

    Acceleration and Deceleration in the Internationalization Process of the Firm

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    By adopting a processual and dynamic view on internationalization, we develop the concepts of acceleration and deceleration, providing analytical tools to enhance our understanding of the non-linearity and multidimensionality of internationalization. We argue that acceleration and deceleration are embedded in the internationalization process and are a consequence of the firm’s capability to absorb and integrate acquired knowledge, and to find and exploit opportunities. In addition, we advance the idea that changes in speed are further influenced by how the firm integrates and coordinates the resources it has deployed within and across various internationalization dimensions. Thus, it emerges that the overall evolution of commitment to internationalization is more complex than received theories tend to present; therefore, empirical studies should aim to include a wide set of international activities and processes embedded in time

    Impact of Dendritic Size and Dendritic Topology on Burst Firing in Pyramidal Cells

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    Neurons display a wide range of intrinsic firing patterns. A particularly relevant pattern for neuronal signaling and synaptic plasticity is burst firing, the generation of clusters of action potentials with short interspike intervals. Besides ion-channel composition, dendritic morphology appears to be an important factor modulating firing pattern. However, the underlying mechanisms are poorly understood, and the impact of morphology on burst firing remains insufficiently known. Dendritic morphology is not fixed but can undergo significant changes in many pathological conditions. Using computational models of neocortical pyramidal cells, we here show that not only the total length of the apical dendrite but also the topological structure of its branching pattern markedly influences inter- and intraburst spike intervals and even determines whether or not a cell exhibits burst firing. We found that there is only a range of dendritic sizes that supports burst firing, and that this range is modulated by dendritic topology. Either reducing or enlarging the dendritic tree, or merely modifying its topological structure without changing total dendritic length, can transform a cell's firing pattern from bursting to tonic firing. Interestingly, the results are largely independent of whether the cells are stimulated by current injection at the soma or by synapses distributed over the dendritic tree. By means of a novel measure called mean electrotonic path length, we show that the influence of dendritic morphology on burst firing is attributable to the effect both dendritic size and dendritic topology have, not on somatic input conductance, but on the average spatial extent of the dendritic tree and the spatiotemporal dynamics of the dendritic membrane potential. Our results suggest that alterations in size or topology of pyramidal cell morphology, such as observed in Alzheimer's disease, mental retardation, epilepsy, and chronic stress, could change neuronal burst firing and thus ultimately affect information processing and cognition

    Effects of a caregiver-inclusive assistive technology intervention: a randomized controlled trial

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    Background: The principal aim of this study was to investigate whether a caregiver-inclusive assistive technology intervention improved older care recipients’ functional autonomy and decreased the perceived burden of their family caregivers compared to customary care. Methods: The study was a single-blind, mixed-methods, randomized controlled trial with baseline data collection and follow-ups at 6-, 22-, and 58-weeks after baseline evaluation, which was prospectively registered (ClinicalTrials.gov Identifier: NCT01640470. Registered 11/21/2011). Dyads comprising a care recipient and family caregiver were randomly assigned to either a caregiver-inclusive experimental group (N = 44) or a customary-care comparison group (N = 46). Eligible care recipients were aged ≥55 years and had one or more limitations with mobility or daily activities, and family caregivers provided at least four hours per week of assistance. Outcome measures were administered to both groups at baseline and at the three follow-up time points. The data collectors were blinded regarding participants’ intervention group. The primary outcome measures were the Functional Autonomy Measurement System to assess care recipients’ functional performance, and the Caregiver Assistive Technology Outcome Measure to assess caregivers’ burden. Qualitative interviews examined participants’ perceptions of the caregiver-inclusive and customary care interventions. Results: The experimental intervention addressed significantly more dyad-identified problematic activities, but caregiver involvement was evident in both groups and outcomes were not significantly different over time. In both groups, care recipients’ functional autonomy declined significantly (P < .01), and caregivers’ activity-specific and overall burden decreased significantly (P < .01). Conclusions: Given the unintended congruence between the caregiver-inclusive and customary care interventions, the overall findings lend support for the provision of assistive technology to reduce caregiver burden.Medicine, Faculty ofOther UBCNon UBCOccupational Science and Occupational Therapy, Department ofReviewedFacult
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