Uncovering Dynamic Capabilities for Service Innovation: Conceptualization and Measurement

NARCIS (Netherlands)

Janssen, M.; Alexiev, A.S.; Castaldi, C.; Den Hertog, P.

2013-01-01

The dynamic capabilities view (DCV) is in need of a solid empirical grounding. Existing attempts to identify the organizational behaviour (or microfoundations) on which dynamic capabilities rely are largely biased towards manufacturing. Thereby, these conceptualizations overlook some of the aspects

Gendering dynamic capabilities in micro firms

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Yevgen Bogodistov

2017-05-01

Full Text Available Gender issues are well-researched in the general management literature, particular in studies on new ventures. Unfortunately, gender issues have been largely ignored in the dynamic capabilities litera­ture. We address this gap by analyzing the effects of gender diversity on dynamic capabilities among micro firms. We consider the gender of managers and personnel in 124 Ukrainian tourism micro firms. We examine how a manager’s gender affects the firm’s sensing capacities and investigate how it moderates team gender diversity’s impact on sensing capacities. We also investigate how person­nel composition impacts seizing and reconfiguration capacities. We find that female managers have several shortcomings concerning a firm’s sensing capacity but that personnel gender diversity increa­ses this capacity. Team gender diversity has positive effects on a firm’s seizing and reconfiguration abilities. Our study advances research on gender diversity and its impact on firm capabilities and illustrates its relevance for staffing practices in micro firms.

Dynamic capabilities, creative action, and poetics

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Donald MacLean

2017-05-01

Full Text Available Research on dynamic capabilities explores how businesses change enables enterprises to remain competitive. However, theory on dynamic capabilities still struggles to capture novelty, the essence of change. This study argues that a full understanding of strategic change requires us to sharpen our focus on real people and experiences; in turn, we must incorporate other faculties, which almost always operate alongside our logical ones, into our theory. We must pay more attention to the “non­-rational” sides of ourselves—including, but not limited to, our imaginations, intuitions, attractions, biographies, preferences, and aesthetic faculties and capabilities. We argue that all such faculties, on the one hand, are central to our abilities to comprehend and cope with complexity and, on the other hand, foster novel understandings, potential responses, and social creativity. This study intro­duces the possibility of an alternative form of inquiry that highlights the role of poetic faculties in strategic behavior and change.

Blind spots of dynamic capabilities: A systems theoretic perspective

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Robert Burisch

2016-05-01

Full Text Available Dynamic capabilities remain one of the most popular, but also one of the most controversial topics in current knowledge and innovation research. This study exposes strengths and weaknesses of existing conceptualizations of dynamic capabilities by using a systems theoretic lens. Systems theory suggests that organizations operate in environments they cannot fully understand. Thus, organizational action patterns inevitably involve simplification, selectivity and uncertainty leading to inherent blind spots in every kind of strategic action. As the resulting insight, fully flexible organizational capabilities might not be achievable and continuous adaptation to every kind of environmental change cannot be possible from a systems theoretic perspective. Accordingly, this work discusses empirical difficulties that derive from the preceding argumentation and outlines a corresponding re-conceptualization of the dynamic capabilities concept.

Dual spinal lesion paradigm in the cat: evolution of the kinematic locomotor pattern.

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Barrière, Grégory; Frigon, Alain; Leblond, Hugues; Provencher, Janyne; Rossignol, Serge

2010-08-01

The recovery of voluntary quadrupedal locomotion after an incomplete spinal cord injury can involve different levels of the CNS, including the spinal locomotor circuitry. The latter conclusion was reached using a dual spinal lesion paradigm in which a low thoracic partial spinal lesion is followed, several weeks later, by a complete spinal transection (i.e., spinalization). In this dual spinal lesion paradigm, cats can express hindlimb walking 1 day after spinalization, a process that normally takes several weeks, suggesting that the locomotor circuitry within the lumbosacral spinal cord had been modified after the partial lesion. Here we detail the evolution of the kinematic locomotor pattern throughout the dual spinal lesion paradigm in five cats to gain further insight into putative neurophysiological mechanisms involved in locomotor recovery after a partial spinal lesion. All cats recovered voluntary quadrupedal locomotion with treadmill training (3-5 days/wk) over several weeks. After the partial lesion, the locomotor pattern was characterized by several left/right asymmetries in various kinematic parameters, such as homolateral and homologous interlimb coupling, cycle duration, and swing/stance durations. When no further locomotor improvement was observed, cats were spinalized. After spinalization, the hindlimb locomotor pattern rapidly reappeared, but left/right asymmetries in swing/stance durations observed after the partial lesion could disappear or reverse. It is concluded that, after a partial spinal lesion, the hindlimb locomotor pattern was actively maintained by new dynamic interactions between spinal and supraspinal levels but also by intrinsic changes within the spinal cord.

Dynamic capabilities and innovation: a Multiple-Case Study

OpenAIRE

Bravo Ibarra, Edna Rocío; Mundet Hiern, Joan; Suñé Torrents, Albert

2009-01-01

After a detailed survey of the scientific literature, it was found that several characteristics of dynamic capabilities were similar to those of innovation capability. Therefore, with a deeper study of the first ones, it could be possible to design a model aimed to structure innovation capability. Thus, this work presents a conceptual model, where the innovation capability is shown as result of three processes: knowledge absorption and creation capability, knowledge integration and knowledge ...

Dynamic capabilities from an institutionalist viewpoint

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José Bonfim Albuquerque Filho

Full Text Available Abstract The purpose of this paper is to elucidate the effects of strategic, technical and institutional response, in the perspective of dynamic capability facing environmental changes, considering that the literature has few references on how institutional factors contribute to a firm’s dynamic capabilities. A case study was conducted on the oldest journalistic enterprise in Brazil. It was found that the organizational practices with dynamic capabilities were conditioned by mechanisms and factors that have extrapolated intentions, expectations, and planning skills of the firm’s own Board of Directors. The new social structure found in the organization is based on the interpretations of the journalists themselves, regarding the social reality of the field of journalism, was supported by the coherent interpretative schemata of some managers in order to reduce the uncertainty caused by institutional demands of the rapidly changing reading habits of people. The study revealed that strategic practices such as making the newspaper known at schools, development of a digital newspaper, showed the influence of institutions as a new normative order, social responsibility, greater legitimacy, and at the same time, a higher capacity of the organization to adapt to its business environment. These aspects, reflect a cultural structure that is reproduced at the company in its practices for the continuous use of new technologies and new social demands.

Either brain-derived neurotrophic factor or neurotrophin-3 only neurotrophin-producing grafts promote locomotor recovery in untrained spinalized cats.

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Ollivier-Lanvin, Karen; Fischer, Itzhak; Tom, Veronica; Houlé, John D; Lemay, Michel A

2015-01-01

Background. Transplants of cellular grafts expressing a combination of 2 neurotrophic factors, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) have been shown to promote and enhance locomotor recovery in untrained spinalized cats. Based on the time course of recovery and the absence of axonal growth through the transplants, we hypothesized that recovery was due to neurotrophin-mediated plasticity within the existing locomotor circuitry of the lumbar cord. Since BDNF and NT-3 have different effects on axonal sprouting and synaptic connectivity/strengthening, it becomes important to ascertain the contribution of each individual neurotrophins to recovery. Objective. We studied whether BDNF or NT-3 only producing cellular grafts would be equally effective at restoring locomotion in untrained spinal cats. Methods. Rat fibroblasts secreting one of the 2 neurotrophins were grafted into the T12 spinal transection site of adult cats. Four cats in each group (BDNF alone or NT-3 alone) were evaluated. Locomotor recovery was tested on a treadmill at 3 and 5 weeks post-transection/grafting. Results. Animals in both groups were capable of plantar weight-bearing stepping at speed up to 0.8 m/s as early as 3 weeks and locomotor capabilities were similar at 3 and 5 weeks for both types of graft. Conclusions. Even without locomotor training, either BDNF or NT-3 only producing grafts promote locomotor recovery in complete spinal animals. More clinically applicable delivery methods need to be developed. © The Author(s) 2014.

“Coupled processes” as dynamic capabilities in systems integration

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Milton de Freitas Chagas Jr.

2017-05-01

Full Text Available The dynamics of innovation in complex systems industries is becoming an independent research stream. Apart from conventional uncertainties related to commerce and technology, complex-system industries must cope with systemic uncertainty. This paper’s objective is to analyze evolving technological paths from one product generation to the next through two case studies in the Brazilian aerospace indus­try, considering systems integration as an empirical instantiation of dynamic capabilities. A proposed “coupled processes” model intertwines two organizational processes regarded as two levels of dynamic capabilities: new product and technological developments. The model addresses the role of emergent properties in shaping a firm’s technological base. Moreover, it uses a technology readiness level to unveil systems integration business tricks and as a decision-making yardstick. The “coupled processes” model is revealed as a set of dynamic capabilities presenting ambidexterity in complex systems indus­tries, a finding that may be relevant for newly industrialized economies.

Mechanism of supply chain coordination cased on dynamic capability framework-the mediating role of manufacturing capabilities

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Tiantian Gao

2014-10-01

Full Text Available Purpose: A critical issue has been absent from the conversation on supply chain coordination: how supply chain coordination influence the enterprise performance. This research proposes a new vision to research the performance mechanism of supply chain coordination capability as a dynamic capability. Manufacturing capabilities are existed as mediating role. Design/methodology/approach: Data from International Manufacturing Strategy Survey in 2009 is used to verify the mediating model by hierarchical regression analysis. Findings: The results show that supply chain coordination impacts the enterprise performance positively and indirect impacts the enterprise performance through quality, cost, flexibility. Research implications: This study presents an overview of the impact of supply chain coordination and manufacturing capabilities on enterprise performance, giving grasp for further research of the relationships that exist between them. Originality/value: This finding integrates insights from previous research in dynamic capability framework and supply chain management into a generalization and extension of the performance mechanism in manufacturing enterprises.

Dynamic Capabilities and Firm Performance: A Case of Two SMEs in Pakistan

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Qazi Muhammad Moinuddin Abro

2011-07-01

Full Text Available This paper investigates the inter-relationship among entrepreneurship, dynamic capabilities and innovation. Entrepreneur\\'s foresights and insights of ICT (Information and Communication Technologies tend to affect their choices of resources and development of dynamic capabilities, leading to different results of innovation. Based on the literature of business innovation and dynamic capabilities, this paper provides a model addressing the links between leadership, with insights and foresights for technology exploration and exploitation, and organizational capabilities of resource integration, learning and transformation to accelerate innovation. A comparative analysis of the two textile manufacturers in Pakistan revealed a cyclical process between the leadership decisions and dynamic capabilities of leveraging ICT for sustained competitiveness in these two SMEs (Small and Medium Sized Enterprises. The result suggests that to build strong capabilities for continuous innovation in today\\'s dynamic business environment, firms need to have leadership with both the attitude and behavior of entrepreneurship, combining the foresight to capture opportunities through ICT and the insight to guide and manage internal resources to achieve ICT-enabled innovation.

Fractional-Order Information in the Visual Control of Lateral Locomotor Interception

NARCIS (Netherlands)

Bootsma, Reinoud J.; Ledouit, Simon; Casanova, Remy; Zaal, Frank T. J. M.

Previous work on locomotor interception of a target moving in the transverse plane has suggested that interception is achieved by maintaining the target's bearing angle (often inadvertently confused and/or confounded with the target heading angle) at a constant value. However, dynamics-based model

An Analytical Framework for Miles and Snow Typology and Dynamic Capabilities

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Tomas Sparano Martins

2014-03-01

Full Text Available The literature on dynamic capabilities is confusing, full of overlapping definitions, and contradictions. The theoretical and practical importance of developing and applying dynamic capabilities to sustain competitive advantage in complex external environment is central in studies about strategy nowadays. In this paper, we offer a definition of dynamic capabilities under two aspects: first, it refers to the shifting character of the environment; second, it emphasizes the key role of strategic management in appropriately adapting, integrating, and re-configuring internal and external organizational skills, resources, and functional competences towards a changing environment. This paper aims to clarify the concept of dynamic capabilities, propose an analytical framework that connects this “new” concept to a well known and recognized generic strategic model (Miles and Snow, 1978 and to the concept of sustainable competitive advantage and evolutionary fit. DOI:10.5585/riae.v13i1.1934

[Age-specific dynamics of mental working capacity in different regimens of locomotor activity].

Science.gov (United States)

Miakotnykh, V V; Khodasevich, L S

2012-01-01

The present study included a total of 392 practically healthy men aged between 40 and 79 years differing in the character of routine locomotor activity and the training status (from masters of sport of international grade to the subjects who had never been engaged in sporting activities). They were divided into 4 groups each comprised of subjects ranged by age with a ten-year interval. Their mental working capacity was estimated from the results of the correction test. The study demonstrated that the subjects characterized by a high level of day-to-day locomotor activity have higher indices of attention intensity and information processing speed compared with the age-matched ones leading a relatively sedentary lifestyle. Moreover, they have better chances to retain the mental working capacity up to the age of 70 years.

Locomotor circumvention strategies are altered by stroke: I. Obstacle clearance.

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Darekar, Anuja; Lamontagne, Anouk; Fung, Joyce

2017-06-15

Functional locomotion requires the ability to adapt to environmental challenges such as the presence of stationary or moving obstacles. Difficulties in obstacle circumvention often lead to restricted community ambulation in individuals with stroke. The objective of this study was to contrast obstacle circumvention strategies between post-stroke (n = 12) and healthy individuals (n = 12) performing locomotor and perceptuomotor (joystick navigation) tasks with different obstacle approaches. Participants walked and navigated with a joystick towards a central target, in a virtual environment simulating a large room, while avoiding an obstacle that either remained stationary at the pre-determined point of intersection or moved from head-on or diagonally 30° left/right. The outcome measures included dynamic clearance (DC), instantaneous distance from obstacle at crossing (IDC), number of collisions and preferred side of circumvention. These measures were compared between groups (stroke vs. healthy), obstacle parameter (stationary vs. moving head-on) and direction of approach (left/paretic vs. right/non-paretic). DC was significantly larger when circumventing a moving obstacle that approached head-on as compared to a stationary obstacle for both groups during both tasks, while not significantly different in either diagonal approach in either group. IDC was smaller in the stroke group while walking and larger in both groups during joystick navigation when avoiding moving as compared to stationary obstacle. IDC was significantly larger in the stroke group compared to controls for diagonal approaches during walking, wherein two different strategies emerged amongst individuals with stroke: circumventing to the same (V same n = 6) or opposite (V opp n = 4) side of obstacle approach. This behavior was not seen in the perceptuomotor task, wherein post-stroke participants circumvented to opposite side of the obstacle approach as seen in healthy participants. In the

DYNAMIC CAPABILITIES AND CREATING ORGANIZATIONAL KNOWLEDGE: IMPORTANT LINKAGE FOR BUILDING COMPETITIVE ADVANTAGE

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Sugiono A.

2017-08-01

Full Text Available As a concept derived from the resource-based view, dynamic capabilities essentially have an important linkage with activities related to the creation of organizational knowledge. Using literature study method, this paper aims to discuss the linkage between the creation of dynamic knowledge capabilities and the creation of knowledge company. The study shows that the discussion of dynamic capabilities creation finally puts both learning and knowledge in an important position. Correspondingly, the relationship between a growth strategy that is generally chosen by the organization brings a consequence that the creation of organizational knowledge becomes something that can not be ignored. In order to make the process of knowledge creation in line with dynamic capabilities creation within a growth strategy creation framework, we need a dynamic process of knowledge creation. Among the various models of knowledge creation, SECI model still becomes a relevant model within organizational knowledge creation framework. In general, this study is still theoretical, therefore, more empirical subsequent discussions are expected.

Enhanced persistency of resting and active periods of locomotor activity in schizophrenia.

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Wataru Sano

Full Text Available Patients with schizophrenia frequently exhibit behavioral abnormalities associated with its pathological symptoms. Therefore, a quantitative evaluation of behavioral dynamics could contribute to objective diagnoses of schizophrenia. However, such an approach has not been fully established because of the absence of quantitative biobehavioral measures. Recently, we studied the dynamical properties of locomotor activity, specifically how resting and active periods are interwoven in daily life. We discovered universal statistical laws ("behavioral organization" and their alterations in patients with major depressive disorder. In this study, we evaluated behavioral organization of schizophrenic patients (n = 19 and healthy subjects (n = 11 using locomotor activity data, acquired by actigraphy, to investigate whether the laws could provide objective and quantitative measures for a possible diagnosis and assessment of symptoms. Specifically, we evaluated the cumulative distributions of resting and active periods, defined as the periods with physical activity counts successively below and above a predefined threshold, respectively. Here we report alterations in the laws governing resting and active periods; resting periods obeyed a power-law cumulative distribution with significantly lower parameter values (power-law scaling exponents, whereas active periods followed a stretched exponential distribution with significantly lower parameter values (stretching exponents, in patients. Our findings indicate enhanced persistency of both lower and higher locomotor activity periods in patients with schizophrenia, probably reflecting schizophrenic pathophysiology.

The use of dynamic capabilities to boost innovation in a Brazilian Chemical Company

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Cristiane Froehlich

Full Text Available Abstract Dynamic capabilities seek to explain how competitive advantages can be built in rapidly changing environments. This study aims to assess how the application of dynamic capabilities can contribute to the expansion of innovation capabilities. Data was collected on ten semi-structured interviews with executives from a chemical company, and analyzed using qualitative content analysis. Results indicate that the application of dynamic capabilities contributes to the development of innovation capabilities through the consolidation of the first dynamic capability (sensing, which fosters innovation. Sensing can be considered an organizational capability, resulting from the integration between organizational strategies and the innovation practices of the organization as a whole. This study brings the following contributions the need to include a new microfoundation in the sensing capability, which in this study is called ‘processes to manage innovation on a strategic level' and the need to adapt another microfoundation related to the sensing capability, called ‘processes oriented toward collaboration with suppliers to complement and stimulate innovations within the company'. It is suggested that these processes should be reassessed in terms of their potential to generate and complement organizational innovation.

Locomotor adaptation to a soleus EMG-controlled antagonistic exoskeleton.

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Gordon, Keith E; Kinnaird, Catherine R; Ferris, Daniel P

2013-04-01

Locomotor adaptation in humans is not well understood. To provide insight into the neural reorganization that occurs following a significant disruption to one's learned neuromuscular map relating a given motor command to its resulting muscular action, we tied the mechanical action of a robotic exoskeleton to the electromyography (EMG) profile of the soleus muscle during walking. The powered exoskeleton produced an ankle dorsiflexion torque proportional to soleus muscle recruitment thus limiting the soleus' plantar flexion torque capability. We hypothesized that neurologically intact subjects would alter muscle activation patterns in response to the antagonistic exoskeleton by decreasing soleus recruitment. Subjects practiced walking with the exoskeleton for two 30-min sessions. The initial response to the perturbation was to "fight" the resistive exoskeleton by increasing soleus activation. By the end of training, subjects had significantly reduced soleus recruitment resulting in a gait pattern with almost no ankle push-off. In addition, there was a trend for subjects to reduce gastrocnemius recruitment in proportion to the soleus even though only the soleus EMG was used to control the exoskeleton. The results from this study demonstrate the ability of the nervous system to recalibrate locomotor output in response to substantial changes in the mechanical output of the soleus muscle and associated sensory feedback. This study provides further evidence that the human locomotor system of intact individuals is highly flexible and able to adapt to achieve effective locomotion in response to a broad range of neuromuscular perturbations.

Locomotor adaptation to a soleus EMG-controlled antagonistic exoskeleton

Science.gov (United States)

Kinnaird, Catherine R.; Ferris, Daniel P.

2013-01-01

Locomotor adaptation in humans is not well understood. To provide insight into the neural reorganization that occurs following a significant disruption to one's learned neuromuscular map relating a given motor command to its resulting muscular action, we tied the mechanical action of a robotic exoskeleton to the electromyography (EMG) profile of the soleus muscle during walking. The powered exoskeleton produced an ankle dorsiflexion torque proportional to soleus muscle recruitment thus limiting the soleus' plantar flexion torque capability. We hypothesized that neurologically intact subjects would alter muscle activation patterns in response to the antagonistic exoskeleton by decreasing soleus recruitment. Subjects practiced walking with the exoskeleton for two 30-min sessions. The initial response to the perturbation was to “fight” the resistive exoskeleton by increasing soleus activation. By the end of training, subjects had significantly reduced soleus recruitment resulting in a gait pattern with almost no ankle push-off. In addition, there was a trend for subjects to reduce gastrocnemius recruitment in proportion to the soleus even though only the soleus EMG was used to control the exoskeleton. The results from this study demonstrate the ability of the nervous system to recalibrate locomotor output in response to substantial changes in the mechanical output of the soleus muscle and associated sensory feedback. This study provides further evidence that the human locomotor system of intact individuals is highly flexible and able to adapt to achieve effective locomotion in response to a broad range of neuromuscular perturbations. PMID:23307949

The Locomotor Capabilities Index; validity and reliability of the Swedish version in adults with lower limb amputation

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Andersson Ingemar H

2009-05-01

Full Text Available Abstract Background The Locomotor Capabilities Index (LCI is a validated measure of lower-limb amputees' ability to perform activities with prosthesis. We have developed the LCI Swedish version and evaluated its validity and reliability. Methods Cross-cultural adaptation to Swedish included forward/backward translations and field testing. The Swedish LCI was then administered to 144 amputees (55 women, mean age 74 (40–93 years, attending post-rehabilitation prosthetic training. Construct validity was assessed by examining the relationship between the LCI and Timed "Up-and-Go" (TUG test and between the LCI and EQ-5D health utility index in 2 subgroups of 40 and 20 amputees, respectively. Discriminative validity was assessed by comparing scores in different age groups and in unilateral and bilateral amputees. Test-retest reliability (1–2 weeks was evaluated in 20 amputees (14 unilateral. Results The Swedish LCI showed good construct convergent validity, with high correlation with the TUG (r = -0.75 and the EQ-5D (r = 0.84, and discriminative validity, with significantly worse mean scores for older than younger and for bilateral than unilateral amputees (p Conclusion The Swedish version of the LCI demonstrated good validity and internal consistency in adult amputees. Test-retest reliability in a small subsample appears to be acceptable. The high ceiling effect of the LCI may imply that it would be most useful in assessing amputees with low to moderate functional abilities.

Predictive Measures of Locomotor Performance on an Unstable Walking Surface

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Bloomberg, J. J.; Peters, B. T.; Mulavara, A. P.; Caldwell, E. E.; Batson, C. D.; De Dios, Y. E.; Gadd, N. E.; Goel, R.; Wood, S. J.; Cohen, H. S.;

Dynamic capabilities and network benefits

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Helge Svare

2017-01-01

Full Text Available The number of publicly funded initiatives to establish or strengthen networks and clusters, in order to enhance innovation, has been increasing. Returns on such investments vary, and the aim of this study is to explore to what extent the variation in benefits for firms participating in networks or clusters can be explained by their dynamic capabilities (DC. Based on survey data from five Norwegian networks, the results suggest that firms with higher DC are more successful in harvesting the potential benefits of being member of a network.

The Influence of Industry Characteristics and Dynamic Capabilities on Firms’ Profitability

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Maja Pervan

2017-12-01

Full Text Available The aim of this research was to explore one of the most intriguing dimensions of every firm’s business—its performance. Aside from analysing the influence of industry’s characteristics on the firm’s performance, the authors addressed the characteristics of dynamic capabilities and their role in contribution to the firm’s ultimate success. The analysis was conducted on a sample of 118 small Croatian manufacturing companies. The application of the Structural Equation Modelling (SEM approach revealed a statistically significant influence of both the industry’s characteristics (represented by Porter’s five forces framework and dynamic capabilities (based on Teece’s theory on the firm’s performance, where the influence of dynamic capabilities is proven to be larger than that of the industry.

Dynamic capabilities for cooperation in Brazilian multinational and factors determining its management

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Priscila Rezende da Costa

2015-05-01

Full Text Available In the context of emerging companies’ growth, current challenges depend on the local generation of product and process innovations, as well as dynamic capability to generate innovative solutions cooperatively and new globe business models. The objective of this study is to analyse the determining managerial factors for the dynamic capability of cooperation in Brazilian multinationals (BMNs. A survey was conducted with a sample of 60 BMNs, and a structured questionnaire and statistical tests with factorial analysis and Cronbach's alpha were used. The aggregate analysis of the results indicates that BMNs are going through a transitional process between the operational capability of cooperation and the capability for dynamic cooperation, which are relevant to the continuous adaptation of already-established cooperative management routines and the evaluation and incorporation of the relational capability of management practices that consider systemic flows, open innovation and integrate strategic intentionality into cooperative processes.

Internationalisation of construction business and e-commerce: Innovation, integration and dynamic capabilities

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Thayaparan Gajendran

2013-06-01

Full Text Available Despite the role of internet and web based applications in delivering competitive advantage through e-business process is widely acknowledged, little is done by way of research to use the dynamic capability framework, in exploring the role of ecommerce in the construction business internationalisation. The aim of this paper is to present a literature based theoretical exploration using dynamic capability view to discuss internationalising construction businesses through electronic commerce (e-commerce platforms. This paper contextualises the opportunities for internationalising construction, using a mix of supply chain paradigms, embedded with e-commerce platforms. The paper concludes by identifying the potential of dynamic capabilities of a firm, exploiting the innovation and integration potential of different e-business systems, in contributing to the internationalisation of construction businesses. It proposes that contracting firms with developed dynamic capabilities, has the potential to exploit e-commerce platforms to channel upstream activities to an international destination, and also offers the firm’s products/services to international markets.

Stimulation of the mesencephalic locomotor region for gait recovery after stroke.

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Fluri, Felix; Malzahn, Uwe; Homola, György A; Schuhmann, Michael K; Kleinschnitz, Christoph; Volkmann, Jens

2017-11-01

One-third of all stroke survivors are unable to walk, even after intensive physiotherapy. Thus, other concepts to restore walking are needed. Because electrical stimulation of the mesencephalic locomotor region (MLR) is known to elicit gait movements, this area might be a promising target for restorative neurostimulation in stroke patients with gait disability. The present study aims to delineate the effect of high-frequency stimulation of the MLR (MLR-HFS) on gait impairment in a rodent stroke model. Male Wistar rats underwent photothrombotic stroke of the right sensorimotor cortex and chronic implantation of a stimulating electrode into the right MLR. Gait was assessed using clinical scoring of the beam-walking test and video-kinematic analysis (CatWalk) at baseline and on days 3 and 4 after experimental stroke with and without MLR-HFS. Kinematic analysis revealed significant changes in several dynamic and static gait parameters resulting in overall reduced gait velocity. All rats exhibited major coordination deficits during the beam-walking challenge and were unable to cross the beam. Simultaneous to the onset of MLR-HFS, a significantly higher walking speed and improvements in several dynamic gait parameters were detected by the CatWalk system. Rats regained the ability to cross the beam unassisted, showing a reduced number of paw slips and misses. MLR-HFS can improve disordered locomotor function in a rodent stroke model. It may act by shielding brainstem and spinal locomotor centers from abnormal cortical input after stroke, thus allowing for compensatory and independent action of these circuits. Ann Neurol 2017;82:828-840. © 2017 American Neurological Association.

Dynamic capability in an under-researched cultural environment

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Fatemeh Rezaee

2016-02-01

Full Text Available During the past few years, dynamic capability (DC has been considered as an important issue in banking industry. This paper presents a survey on dynamic capability and its role on reaching sustainable competitive advantage (SCA within Mellat bank of Iran (MBI. A valid research instrument is utilized to conduct a survey among 150 managers from MBI. The study utilizes structural equation modelling to examine different hypotheses based on an integrated model of DC and SCA. According to literature studies, expert opinions and exploratory factor analysis, DC is classified into sensing, learning, reconfiguration, and coordination. Furthermore, SCA of the banking industry is classified into three dimensions: market, customer, and financial performance. The results indicate that DC had the greatest effect on the market centered, while it had the least influence on the customer centered.

Disruption of locomotor adaptation with repetitive transcranial magnetic stimulation over the motor cortex

DEFF Research Database (Denmark)

Choi, Julia Tsok Lam; Bouyer, Laurent J; Nielsen, Jens Bo

2015-01-01

Locomotor patterns are adapted on a trial-and-error basis to account for predictable dynamics. Once a walking pattern is adapted, the new calibration is stored and must be actively de-adapted. Here, we tested the hypothesis that storage of newly acquired ankle adaptation in walking is dependent...

Dynamic Capabilities of Universities in the Knowledge Economy

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Ruxandra BEJINARU

2017-12-01

Full Text Available The purpose of this paper is to analyze how universities can develop dynamic capabilities based on their strategic resources in order to increase their competitiveness in the knowledge economy. ”Dynamic capabilities” is a concept introduced by Teece, Pisano, and Shuen (1997 to emphasize the managerial capacity of a given organization of using efficiently its strategic resources in transforming opportunities in business success. They reflect the capacity of the organization to sense, seize, adapt to the changing environment. For a university, the most important strategic resources are information, knowledge, and ideas which constitute its intellectual capital. The present paper is analyzing critically these strategic resources of a university and the necessary conditions to develop dynamic capabilities in order to use efficiently these resources in a turbulent economic environment. Universities are in the knowledge economy the most important hubs for knowledge creation and its transfer to the students, as well as to their communities. At the same time, professors contribute to the development of the generic thinking skills of their students to help them for employability in a future with many new jobs and new business activities.

FES-assisted Cycling Improves Aerobic Capacity and Locomotor Function Postcerebrovascular Accident.

Science.gov (United States)

Aaron, Stacey E; Vanderwerker, Catherine J; Embry, Aaron E; Newton, Jennifer H; Lee, Samuel C K; Gregory, Chris M

2018-03-01

After a cerebrovascular accident (CVA) aerobic deconditioning contributes to diminished physical function. Functional electrical stimulation (FES)-assisted cycling is a promising exercise paradigm designed to target both aerobic capacity and locomotor function. This pilot study aimed to evaluate the effects of an FES-assisted cycling intervention on aerobic capacity and locomotor function in individuals post-CVA. Eleven individuals with chronic (>6 months) post-CVA hemiparesis completed an 8-wk (three times per week; 24 sessions) progressive FES-assisted cycling intervention. V˙O2peak, self-selected, and fastest comfortable walking speeds, gait, and pedaling symmetry, 6-min walk test (6MWT), balance, dynamic gait movements, and health status were measured at baseline and posttraining. Functional electrical stimulation-assisted cycling significantly improved V˙O2peak (12%, P = 0.006), self-selected walking speed (SSWS, 0.05 ± 0.1 m·s, P = 0.04), Activities-specific Balance Confidence scale score (12.75 ± 17.4, P = 0.04), Berg Balance Scale score (3.91 ± 4.2, P = 0.016), Dynamic Gait Index score (1.64 ± 1.4, P = 0.016), and Stroke Impact Scale participation/role domain score (12.74 ± 16.7, P = 0.027). Additionally, pedal symmetry, represented by the paretic limb contribution to pedaling (paretic pedaling ratio [PPR]) significantly improved (10.09% ± 9.0%, P = 0.016). Although step length symmetry (paretic step ratio [PSR]) did improve, these changes were not statistically significant (-0.05% ± 0.1%, P = 0.09). Exploratory correlations showed moderate association between change in SSWS and 6-min walk test (r = 0.74), and moderate/strong negative association between change in PPR and PSR. These results support FES-assisted cycling as a means to improve both aerobic capacity and locomotor function. Improvements in SSWS, balance, dynamic walking movements, and participation in familial and societal roles are important targets for rehabilitation of individuals

Dopamine and the Brainstem Locomotor Networks: From Lamprey to Human

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Dimitri Ryczko

2017-05-01

Full Text Available In vertebrates, dopamine neurons are classically known to modulate locomotion via their ascending projections to the basal ganglia that project to brainstem locomotor networks. An increased dopaminergic tone is associated with increase in locomotor activity. In pathological conditions where dopamine cells are lost, such as in Parkinson's disease, locomotor deficits are traditionally associated with the reduced ascending dopaminergic input to the basal ganglia. However, a descending dopaminergic pathway originating from the substantia nigra pars compacta was recently discovered. It innervates the mesencephalic locomotor region (MLR from basal vertebrates to mammals. This pathway was shown to increase locomotor output in lampreys, and could very well play an important role in mammals. Here, we provide a detailed account on the newly found dopaminergic pathway in lamprey, salamander, rat, monkey, and human. In lampreys and salamanders, dopamine release in the MLR is associated with the activation of reticulospinal neurons that carry the locomotor command to the spinal cord. Dopamine release in the MLR potentiates locomotor movements through a D1-receptor mechanism in lampreys. In rats, stimulation of the substantia nigra pars compacta elicited dopamine release in the pedunculopontine nucleus, a known part of the MLR. In a monkey model of Parkinson's disease, a reduced dopaminergic innervation of the brainstem locomotor networks was reported. Dopaminergic fibers are also present in human pedunculopontine nucleus. We discuss the conserved locomotor role of this pathway from lamprey to mammals, and the hypothesis that this pathway could play a role in the locomotor deficits reported in Parkinson's disease.

Assessing the origins, evolution and prospects of the literature on dynamic capabilities: A bibliometric analysis

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Gema Albort-Morant

2018-01-01

Full Text Available The purpose of this study is to serve as orientation and guidance to academics that are starting or currently developing their research within the field of dynamic capabilities, in order to enhance their knowledge about which are the key scientific journals, authors and articles shaping this topic. This paper presents a bibliometric analysis on dynamic capabilities, making use of the Web of Science database to perform it. This analysis comprises fundamental issues such as (i the number of studies published per year, (ii the countries with the highest rate of productivity, (iii the most prolific and influential authors, (iv assessment of studies citing dynamic capabilities, and (v the most productive journals on dynamic capabilities and recent studies on this topic. Results reveal an exponential growth in the number of publications on dynamic capabilities for the 2000–2012 period. Although, since 2012 this growth has decelerated, the number of publications on this topic remains noteworthy. This study brings useful information for those academics and practitioners attempting to analyze and deepen within this particular field of research, at the same time that provides some insights concerning the future development and progress of the dynamic capabilities topic in the management, business and economics academic literature.

Dynamic Primitives in the Control of Locomotion

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Neville eHogan

2013-06-01

Full Text Available Humans achieve locomotor dexterity that far exceeds the capability of modern robots, yet this is achieved despite slower actuators, imprecise sensors and vastly slower communication. We propose that this spectacular performance arises from encoding motor commands in terms of dynamic primitives. We propose three primitives as a foundation for a comprehensive theoretical framework that can embrace a wide range of upper- and lower-limb behaviors. Building on previous work that suggested discrete and rhythmic movements as elementary dynamic behaviors, we define submovements and oscillations: As discrete movements cannot be combined with sufficient flexibility, we argue that suitably-defined submovements are primitives. As the term rhythmic may be ambiguous, we define oscillations as the corresponding class of primitives. We further propose mechanical impedances as a third class of dynamic primitives, necessary for interaction with the physical environment. Combination of these three classes of primitive requires care. One approach is through a generalized equivalent network: a virtual trajectory composed of simultaneous and/or sequential submovements and/or oscillations that interacts with mechanical impedances to produce observable forces and motions. Reliable experimental identification of these dynamic primitives presents challenges: Identification of mechanical impedances is exquisitely sensitive to assumptions about their dynamic structure; identification of submovements and oscillations is sensitive to their assumed form and to details of the algorithm used to extract them. Some methods to address these challenges are presented. Some implications of this theoretical framework for locomotor rehabilitation are considered.

Dynamic primitives in the control of locomotion.

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Hogan, Neville; Sternad, Dagmar

2013-01-01

Humans achieve locomotor dexterity that far exceeds the capability of modern robots, yet this is achieved despite slower actuators, imprecise sensors, and vastly slower communication. We propose that this spectacular performance arises from encoding motor commands in terms of dynamic primitives. We propose three primitives as a foundation for a comprehensive theoretical framework that can embrace a wide range of upper- and lower-limb behaviors. Building on previous work that suggested discrete and rhythmic movements as elementary dynamic behaviors, we define submovements and oscillations: as discrete movements cannot be combined with sufficient flexibility, we argue that suitably-defined submovements are primitives. As the term "rhythmic" may be ambiguous, we define oscillations as the corresponding class of primitives. We further propose mechanical impedances as a third class of dynamic primitives, necessary for interaction with the physical environment. Combination of these three classes of primitive requires care. One approach is through a generalized equivalent network: a virtual trajectory composed of simultaneous and/or sequential submovements and/or oscillations that interacts with mechanical impedances to produce observable forces and motions. Reliable experimental identification of these dynamic primitives presents challenges: identification of mechanical impedances is exquisitely sensitive to assumptions about their dynamic structure; identification of submovements and oscillations is sensitive to their assumed form and to details of the algorithm used to extract them. Some methods to address these challenges are presented. Some implications of this theoretical framework for locomotor rehabilitation are considered.

PROBLEMAS LOCOMOTORES EM FRANGOS DE CORTE - REVISÃO. / LOCOMOTOR PROBLEMS IN BROILER CHICKENS - A REVIEW.

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IBIARA CORREIA DE LIMA ALMEIDA PAZ

2008-12-01

Full Text Available O bem estar animal é, sem dúvida, um dos pontos em que os produtores de aves devem se atentar para conseguir melhor rentabilidade e colocação no mercado externo. No entanto, é necessário ter uma ampla idéia de que alguns pontos impostos por mercados importadores, muitas vezes não tem fundamento científico e tratam-se mais de barreiras não tarifárias que de problemas de produção propriamente ditos. Dentre os vários fatores que afetam o bem estar animal pode-se destacar a incidência de problemas locomotores, principalmente em animais confinados. Estes distúrbios podem acarretar em perdas de até 6% em lotes comercias de frangos de corte, além de outras perdas não mensuráveis em linhas de abate, por fraturas e hematomas. Existem diversas metodologias para diagnosticar problemas locomotores, entretanto, a mais difundida na indústria avícola é o Gait Score, por sua facilidade de aplicação e por englobar os diferentes tipos de problemas locomotores. Sabe-se, contudo que esta metodologia é bastante subjetiva e pode inferir  em  diferentes  níveis  de  avaliação  dependendo  do método  utilizado. Os  problemas locomotores devem ser prevenidos já que depois de estabelecidos as perdas são inevitáveis.

Locomotor activity: A distinctive index in morphine self-administration in rats.

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Zhang, Jian-Jun; Kong, Qingyao

2017-01-01

Self-administration of addictive drugs is a widely used tool for studying behavioral, neurobiological, and genetic factors in addiction. However, how locomotor activity is affected during self-administration of addictive drugs has not been extensively studied. In our present study, we tested the locomotor activity levels during acquisition, extinction and reinstatement of morphine self-administration in rats. We found that compared with saline self-administration (SA), rats that trained with morphine SA had higher locomotor activity. Rats that successfully acquired SA also showed higher locomotor activity than rats that failed in acquiring SA. Moreover, locomotor activity was correlated with the number of drug infusions but not with the number of inactive pokes. We also tested the locomotor activity in the extinction and the morphine-primed reinstatement session. Interestingly, we found that in the first extinction session, although the number of active pokes did not change, the locomotor activity was significantly lower than in the last acquisition session, and this decrease can be maintained for at least six days. Finally, morphine priming enhanced the locomotor activity during the reinstatement test, regardless of if the active pokes were significantly increased or not. Our results clearly suggest that locomotor activity, which may reflect the pharmacological effects of morphine, is different from drug seeking behavior and is a distinctive index in drug self-administration.

Locomotor activity: A distinctive index in morphine self-administration in rats

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Kong, Qingyao

2017-01-01

Self-administration of addictive drugs is a widely used tool for studying behavioral, neurobiological, and genetic factors in addiction. However, how locomotor activity is affected during self-administration of addictive drugs has not been extensively studied. In our present study, we tested the locomotor activity levels during acquisition, extinction and reinstatement of morphine self-administration in rats. We found that compared with saline self-administration (SA), rats that trained with morphine SA had higher locomotor activity. Rats that successfully acquired SA also showed higher locomotor activity than rats that failed in acquiring SA. Moreover, locomotor activity was correlated with the number of drug infusions but not with the number of inactive pokes. We also tested the locomotor activity in the extinction and the morphine-primed reinstatement session. Interestingly, we found that in the first extinction session, although the number of active pokes did not change, the locomotor activity was significantly lower than in the last acquisition session, and this decrease can be maintained for at least six days. Finally, morphine priming enhanced the locomotor activity during the reinstatement test, regardless of if the active pokes were significantly increased or not. Our results clearly suggest that locomotor activity, which may reflect the pharmacological effects of morphine, is different from drug seeking behavior and is a distinctive index in drug self-administration. PMID:28380023

Differential housing and novelty response: Protection and risk from locomotor sensitization.

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Garcia, Erik J; Haddon, Tara N; Saucier, Donald A; Cain, Mary E

2017-03-01

High novelty seeking increases the risk for drug experimentation and locomotor sensitization. Locomotor sensitization to psychostimulants is thought to reflect neurological adaptations that promote the transition to compulsive drug taking. Rats reared in enrichment (EC) show less locomotor sensitization when compared to rats reared in isolation (IC) or standard conditions (SC). The current research study was designed to test if novelty response contributed locomotor sensitization and more importantly, if the different housing environments could change the novelty response to protect against the development of locomotor sensitization in both adolescence and adulthood. Experiment 1: rats were tested for their response to novelty using the inescapable novelty test (IEN) and pseudorandomly assigned to enriched (EC), isolated (IC), or standard (SC) housing conditions for 30days. After housing, they were tested with IEN. Rats were then administered amphetamine (0.5mg/kg) or saline and locomotor activity was measured followed by a sensitization test 14days later. Experiment 2: rats were tested in the IEN test early adulthood and given five administrations of amphetamine (0.3mg/kg) or saline and then either stayed in or switched housing environments for 30days. Rats were then re-tested in the IEN test in late adulthood and administered five more injections of their respective treatments and tested for locomotor sensitization. Results indicate that IC and SC increased the response to novelty. EC housing decreased locomotor response to amphetamine and saline, and SC housing increased the locomotor response to amphetamine. Mediation results indicated that the late adult novelty response fully mediates the locomotor response to amphetamine and saline, while the early adulthood novelty response did not. Differential housing changes novelty and amphetamine locomotor response. Novelty response is altered into adulthood and provides evidence that enrichment can be used to reduce

Architecture of firm dynamic capabilities across inter-organizational activities: Explaining innovativeness in the context of nanotechnology

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Petricevic, Olga

In this dissertation I first develop a theoretical framework that explores different components of dynamic capabilities related to firm's boundary-spanning linkages across two different types of inter-organizational activities---alliances and networks. I argue that there are four different subsets of dynamic capabilities simultaneously at work: alliance opportunity-sensing, alliance opportunity-seizing, network opportunity-sensing and network opportunity-seizing. Furthermore, I argue that there are significant interaction effects between these distinctive subsets driving the firm's overall effectiveness in sensing and seizing of novel and innovative external opportunities. In order to explore potential interdependencies and draw distinctions among different dynamic capability subsets I integrate concepts from the two theoretical perspectives that often neglect the emphasis of the other---the dynamic capability view and the social network perspective. I then test the hypothesized relationships in the context of firms actively patenting in nanotechnology. Nanotechnology innovations are multidisciplinary in nature and require search and discovery across multiple inter-organizational, scientific, geographic, industry, or technological domains by a particular firm. The findings offer support for the conceptualizations of dynamic capabilities as consisting of distinct subsets of capabilities for the sensing and the seizing of external new-knowledge opportunities. The findings suggest that firm's innovativeness in an interdisciplinary scientific field such as nanotechnology is the function of the vector of multi-dimensional dynamic capabilities that are context-specific. Furthermore, the findings also suggest that there are inherent trade-offs embedded in different dimensions of dynamic capabilities when deployed across a wide range of inter-organizational relationships.

Altered Patterns of Reflex Excitability, Balance, and Locomotion Following Spinal Cord Injury (SCI and Locomotor Training.

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Prodip K Bose

2012-07-01

Full Text Available Spasticity is an important problem that complicates daily living in many individuals with SCI. While previous studies in human and animals revealed significant improvements in locomotor ability with treadmill locomotor training, it is not known to what extent locomotor training influences spasticity. In addition, it would be of considerable practical interest to know how the more ergonomically feasible cycle training compares with treadmill training as therapy to manage SCI-induced spasticity and to improve locomotor function. Our present studies were initiated to evaluate the influence of different types of locomotor training on measures of limb spasticity, gait, and reflex components that contribute to locomotion. For these studies, thirty animals received midthoracic SCI using the standard MASCIS protocol (10 g 2.5 cm weight drop. They were divided randomly into three equal groups: control (contused untrained, contused treadmill trained, and contused cycle trained. Velocity-dependent ankle torque was tested across a wide range of velocities (612 – 49 deg/sec to permit quantitation of tonic (low velocity and dynamic (high velocity contributions to lower limb spasticity. Treadmill and cycle training were started on post-injury day 8. By post-injury weeks 4 and 6, the untrained group revealed significant velocity-dependent ankle extensor spasticity, compared to pre-surgical control values. At these post-injury time points, spasticity was not observed in either of the two training groups. Instead, a significantly milder form of velocity dependent spasticity was detected at postcontusion week 8 through 12 in both treadmill and bicycle training groups at the four fastest ankle rotation velocities (350 - 612 deg/sec. Locomotor training using treadmill or bicycle also produced significant increase in the rate of recovery of limb placement measures (limb axis, base of support, and BBB and reflex rate depression, a quantitative assessment of

Modular diversification of the locomotor system in damselfishes (Pomacentridae).

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Aguilar-Medrano, Rosalía; Frédérich, Bruno; Barber, Paul H

2016-05-01

As fish move and interact with their aquatic environment by swimming, small morphological variations of the locomotor system can have profound implications on fitness. Damselfishes (Pomacentridae) have inhabited coral reef ecosystems for more than 50 million years. As such, habitat preferences and behavior could significantly constrain the morphology and evolvability of the locomotor system. To test this hypothesis, we used phylogenetic comparative methods on morphometric, ecological and behavioral data. While body elongation represented the primary source of variation in the locomotor system of damselfishes, results also showed a diverse suite of morphological combinations between extreme morphologies. Results show clear associations between behavior, habitat preferences, and morphology, suggesting ecological constraints on shape diversification of the locomotor system. In addition, results indicate that the three modules of the locomotor system are weakly correlated, resulting in versatile and independent characters. These results suggest that Pomacentridae is shape may result from the interaction between (1) integrated parts of morphological variation that maintain overall swimming ability and (2) relatively independent parts of the morphology that facilitate adaptation and diversification. © 2016 Wiley Periodicals, Inc.

Organizational reputation risk management as a component of the dynamic capabilities management process1

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Krzakiewicz Kazimierz

2015-05-01

Full Text Available Intangible assets, such as reputation, brand value, strategic position, alliances, knowledge, human capital, play an increasingly important role in shaping the market value of an organization. At the same time, in the literature it is emphasized that the attribute of intangibility translates into an increased risk of destruction or impairment of assets. Thus, the research problem associated with the analysis of organizational reputation risk management as a component of the dynamic capabilities management process should be considered important from the point of view of management science. The study attempts to outline the concept of dynamic capabilities, define the concept of risk and subsequently discuss the relationship between dynamic capabilities and organizational reputation risk management.

Locomotor sensitization to ethanol: Contribution of b-Endorphin

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Stephani eDempsey

2012-08-01

Full Text Available Alcohol use disorders, like all drug addictions, involve a constellation of adaptive changes throughout the brain. Neural activity underlying changes in the rewarding properties of alcohol reflect changes in dopamine transmission in mesolimbic and nigrostriatal pathways and these effects are modulated by endogenous opioids such as b-Endorphin. In order to study the role of b-Endorphin in the development of locomotor sensitization to repeated EtOH exposure, we tested transgenic mice that vary in their capacity to synthesize this peptide as a result of constitutive modification of the Pomc gene. Our results indicate that mice deficient in b-Endorphin show attenuated locomotor activation following an acute injection of EtOH (2 g/kg and, in contrast to wildtype mice, fail to demonstrate locomotor sensitization after 12 days of repeated EtOH injections. These data support the idea that b-Endorphin modulates the locomotor effects of EtOH and contributes to the neuroadaptive changes associated with chronic use.

Predictive and Reactive Locomotor Adaptability in Healthy Elderly: A Systematic Review and Meta-Analysis.

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Bohm, Sebastian; Mademli, Lida; Mersmann, Falk; Arampatzis, Adamantios

2015-12-01

Locomotor adaptability is based on the implementation of error-feedback information from previous perturbations to predictively adapt to expected perturbations (feedforward) and to facilitate reactive responses in recurring unexpected perturbations ('savings'). The effect of aging on predictive and reactive adaptability is yet unclear. However, such understanding is fundamental for the design and application of effective interventions targeting fall prevention. We systematically searched the Web of Science, MEDLINE, Embase and Science Direct databases as well as the reference lists of the eligible articles. A study was included if it addressed an investigation of the locomotor adaptability in response to repeated mechanical movement perturbations of healthy older adults (≥60 years). The weighted average effect size (WAES) of the general adaptability (adaptive motor responses to repeated perturbations) as well as predictive (after-effects) and reactive adaptation (feedback responses to a recurring unexpected perturbation) was calculated and tested for an overall effect. A subgroup analysis was performed regarding the factor age group [i.e., young (≤35 years) vs. older adults]. Furthermore, the methodological study quality was assessed. The review process yielded 18 studies [1009 participants, 613 older adults (70 ± 4 years)], which used various kinds of locomotor tasks and perturbations. The WAES for the general locomotor adaptability was 1.21 [95% confidence interval (CI) 0.68-1.74, n = 11] for the older and 1.39 (95% CI 0.90-1.89, n = 10) for the young adults with a significant (p locomotor adaptability in general and predictive and reactive adaptation in particular remain highly effective in the elderly, showing only minor, not statistically significant age-related deficits. Consequently, interventions which use adaptation and learning paradigms including the application of the mechanisms responsible for an effective predictive and reactive dynamic stability

Development of Testing Methodologies to Evaluate Postflight Locomotor Performance

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Mulavara, A. P.; Peters, B. T.; Cohen, H. S.; Richards, J. T.; Miller, C. A.; Brady, R.; Warren, L. E.; Bloomberg, J. J.

2006-01-01

Crewmembers experience locomotor and postural instabilities during ambulation on Earth following their return from space flight. Gait training programs designed to facilitate recovery of locomotor function following a transition to a gravitational environment need to be accompanied by relevant assessment methodologies to evaluate their efficacy. The goal of this paper is to demonstrate the operational validity of two tests of locomotor function that were used to evaluate performance after long duration space flight missions on the International Space Station (ISS).

Locomotor adaptability in persons with unilateral transtibial amputation.

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Darter, Benjamin J; Bastian, Amy J; Wolf, Erik J; Husson, Elizabeth M; Labrecque, Bethany A; Hendershot, Brad D

2017-01-01

Locomotor adaptation enables walkers to modify strategies when faced with challenging walking conditions. While a variety of neurological injuries can impair locomotor adaptability, the effect of a lower extremity amputation on adaptability is poorly understood. Determine if locomotor adaptability is impaired in persons with unilateral transtibial amputation (TTA). The locomotor adaptability of 10 persons with a TTA and 8 persons without an amputation was tested while walking on a split-belt treadmill with the parallel belts running at the same (tied) or different (split) speeds. In the split condition, participants walked for 15 minutes with the respective belts moving at 0.5 m/s and 1.5 m/s. Temporal spatial symmetry measures were used to evaluate reactive accommodations to the perturbation, and the adaptive/de-adaptive response. Persons with TTA and the reference group of persons without amputation both demonstrated highly symmetric walking at baseline. During the split adaptation and tied post-adaptation walking both groups responded with the expected reactive accommodations. Likewise, adaptive and de-adaptive responses were observed. The magnitude and rate of change in the adaptive and de-adaptive responses were similar for persons with TTA and those without an amputation. Furthermore, adaptability was no different based on belt assignment for the prosthetic limb during split adaptation walking. Reactive changes and locomotor adaptation in response to a challenging and novel walking condition were similar in persons with TTA to those without an amputation. Results suggest persons with TTA have the capacity to modify locomotor strategies to meet the demands of most walking conditions despite challenges imposed by an amputation and use of a prosthetic limb.

A neurorobotic platform for locomotor prosthetic development in rats and mice

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von Zitzewitz, Joachim; Asboth, Leonie; Fumeaux, Nicolas; Hasse, Alexander; Baud, Laetitia; Vallery, Heike; Courtine, Grégoire

2016-04-01

Objectives. We aimed to develop a robotic interface capable of providing finely-tuned, multidirectional trunk assistance adjusted in real-time during unconstrained locomotion in rats and mice. Approach. We interfaced a large-scale robotic structure actuated in four degrees of freedom to exchangeable attachment modules exhibiting selective compliance along distinct directions. This combination allowed high-precision force and torque control in multiple directions over a large workspace. We next designed a neurorobotic platform wherein real-time kinematics and physiological signals directly adjust robotic actuation and prosthetic actions. We tested the performance of this platform in both rats and mice with spinal cord injury. Main Results. Kinematic analyses showed that the robotic interface did not impede locomotor movements of lightweight mice that walked freely along paths with changing directions and height profiles. Personalized trunk assistance instantly enabled coordinated locomotion in mice and rats with severe hindlimb motor deficits. Closed-loop control of robotic actuation based on ongoing movement features enabled real-time control of electromyographic activity in anti-gravity muscles during locomotion. Significance. This neurorobotic platform will support the study of the mechanisms underlying the therapeutic effects of locomotor prosthetics and rehabilitation using high-resolution genetic tools in rodent models.

Role of spared pathways in locomotor recovery after body-weight-supported treadmill training in contused rats.

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Singh, Anita; Balasubramanian, Sriram; Murray, Marion; Lemay, Michel; Houle, John

2011-12-01

Body-weight-supported treadmill training (BWSTT)-related locomotor recovery has been shown in spinalized animals. Only a few animal studies have demonstrated locomotor recovery after BWSTT in an incomplete spinal cord injury (SCI) model, such as contusion injury. The contribution of spared descending pathways after BWSTT to behavioral recovery is unclear. Our goal was to evaluate locomotor recovery in contused rats after BWSTT, and to study the role of spared pathways in spinal plasticity after BWSTT. Forty-eight rats received a contusion, a transection, or a contusion followed at 9 weeks by a second transection injury. Half of the animals in the three injury groups were given BWSTT for up to 8 weeks. Kinematics and the Basso-Beattie-Bresnahan (BBB) test assessed behavioral improvements. Changes in Hoffmann-reflex (H-reflex) rate depression property, soleus muscle mass, and sprouting of primary afferent fibers were also evaluated. BWSTT-contused animals showed accelerated locomotor recovery, improved H-reflex properties, reduced muscle atrophy, and decreased sprouting of small caliber afferent fibers. BBB scores were not improved by BWSTT. Untrained contused rats that received a transection exhibited a decrease in kinematic parameters immediately after the transection; in contrast, trained contused rats did not show an immediate decrease in kinematic parameters after transection. This suggests that BWSTT with spared descending pathways leads to neuroplasticity at the lumbar spinal level that is capable of maintaining locomotor activity. Discontinuing training after the transection in the trained contused rats abolished the improved kinematics within 2 weeks and led to a reversal of the improved H-reflex response, increased muscle atrophy, and an increase in primary afferent fiber sprouting. Thus continued training may be required for maintenance of the recovery. Transected animals had no effect of BWSTT, indicating that in the absence of spared pathways this

Ontogenetic scaling of locomotor kinetics and kinematics of the ostrich (Struthio camelus).

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Smith, Nicola C; Jespers, Karin J; Wilson, Alan M

2010-04-01

Kinematic and kinetic parameters of running gait were investigated through growth in the ostrich, from two weeks up to 10 months of age, in order to investigate the effects of increasing body size. Ontogenetic scaling relationships were compared with published scaling relationships found to exist with increasing body size between species to determine whether dynamic similarity is maintained during growth. During the study, ostrich mass (M(b)) ranged from 0.7 kg to 108.8 kg. Morphological measurements showed that lengths scaled with positive allometry during growth (hip height proportional to M(b)(0.40); foot segment length proportional to M(b)(0.40); tarsometatarsus length proportional to M(b)(0.41); tibiotarsus length proportional to M(b)(0.38); femur length proportional to M(b)(0.37)), significantly exceeding the close to geometric scaling observed between mammalian and avian species of increasing body size. Scaling of kinematic variables largely agreed with predicted scaling for increasing size and demonstrated relationships close to dynamic similarity and, as such, ontogenetic scaling of locomotor parameters was similar to that observed with increasing body mass between species. However, the ways in which these scaling trends were achieved were very different, with ontogenetic scaling of locomotor mechanics largely resulting from simple scaling of the limb segments rather than postural changes, likely to be due to developmental constraints. Small deviations from dynamic similarity of kinematic parameters and a reduction in the predicted scaling of limb stiffness (proportional to M(b)(0.59)) were found to be accounted for by the positive allometric scaling of the limb during growth.

Distinct sets of locomotor modules control the speed and modes of human locomotion

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Yokoyama, Hikaru; Ogawa, Tetsuya; Kawashima, Noritaka; Shinya, Masahiro; Nakazawa, Kimitaka

2016-01-01

Although recent vertebrate studies have revealed that different spinal networks are recruited in locomotor mode- and speed-dependent manners, it is unknown whether humans share similar neural mechanisms. Here, we tested whether speed- and mode-dependence in the recruitment of human locomotor networks exists or not by statistically extracting locomotor networks. From electromyographic activity during walking and running over a wide speed range, locomotor modules generating basic patterns of muscle activities were extracted using non-negative matrix factorization. The results showed that the number of modules changed depending on the modes and speeds. Different combinations of modules were extracted during walking and running, and at different speeds even during the same locomotor mode. These results strongly suggest that, in humans, different spinal locomotor networks are recruited while walking and running, and even in the same locomotor mode different networks are probably recruited at different speeds. PMID:27805015

How dynamic capabilities drive performance in the Indian IT industry

DEFF Research Database (Denmark)

Holzweber, Markus; Mattsson, Jan; Chadee, Doren

2012-01-01

This study examines key issues and effects of capability management on a fast-growing area of knowledge-intensive global business services – IT outsourcing and offshoring. An exploratory study of Indian companies providing complex process-oriented offshore IT services to their global customers...... is undertaken. The analysis of the data related to the service provider side shows that developing dynamic capabilities is strongly driven by management and top-clients and results in the development of business processes and in establishing a strategic partnership with the client organization. Key findings...

How do dynamic capabilities transform external technologies into firms’ renewed technological resources? – A mediation model

DEFF Research Database (Denmark)

Li-Ying, Jason; Wang, Yuandi; Ning, Lutao

2016-01-01

microfoundations of dynamic technological capabilities, mediate the relationship between external technology breadth and firms’ technological innovation performance, based on the resource-based view and dynamic capability view. Using a sample of listed Chinese licensee firms, we find that firms must broadly......How externally acquired resources may become valuable, rare, hard-to-imitate, and non-substitute resource bundles through the development of dynamic capabilities? This study proposes and tests a mediation model of how firms’ internal technological diversification and R&D, as two distinctive...... explore external technologies to ignite the dynamism in internal technological diversity and in-house R&D, which play their crucial roles differently to transform and reconfigure firms’ technological resources....

IT-enabled dynamic capability on performance: An empirical study of BSC model

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Adilson Carlos Yoshikuni

2017-05-01

Full Text Available ew studies have investigated the influence of “information capital,” through IT-enabled dynamic capability, on corporate performance, particularly in economic turbulence. Our study investigates the causal relationship between performance perspectives of the balanced scorecard using partial least squares path modeling. Using data on 845 Brazilian companies, we conduct a quantitative empirical study of firms during an economic crisis and observe the following interesting results. Operational and analytical IT-enabled dynamic capability had positive effects on business process improvement and corporate performance. Results pertaining to mediation (endogenous variables and moderation (control variables clarify IT’s role in and benefits for corporate performance.

How Overall Logistics Strategy Mediates The Influence Of Market Attractiveness And Dynamic Capability On Strategic Competitive Response

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Febriyanto

2015-08-01

Full Text Available This research is conducted to examine the influence of market attractiveness and dynamic capability on strategic competitive response through overall logistics strategies of logistics service providers LSPs. Involving 266 LSPs SEM-LISREL is applied to test the hypotheses. The findings reveal that the market attractiveness and the dynamic capability positively affect the overall logistics strategy. Additionally the market attractiveness and the dynamic capability positively affect the strategic competitive response. Indirectly the market attractiveness and the dynamic capability positively affect the performance through strategic competitive response of LSPs. Obviously overall logistics strategy strengthen the influence of both market attractiveness and dynamic capability on strategic competitive response. There are five alternatives to optimize the overall logistics strategy of LSPs market intensification integration focus collaboration and strengthening value proposition. The involvement of overall logistics strategy as mediating variable is new paradigm in the strategic management discourses especially in logistics industry. Further research needs to be performed by involving the size of business as control variable and LSPs perception on Governments policies.

Locomotor training improves premotoneuronal control after chronic spinal cord injury.

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Knikou, Maria; Mummidisetty, Chaithanya K

2014-06-01

Spinal inhibition is significantly reduced after spinal cord injury (SCI) in humans. In this work, we examined if locomotor training can improve spinal inhibition exerted at a presynaptic level. Sixteen people with chronic SCI received an average of 45 training sessions, 5 days/wk, 1 h/day. The soleus H-reflex depression in response to low-frequency stimulation, presynaptic inhibition of soleus Ia afferent terminals following stimulation of the common peroneal nerve, and bilateral EMG recovery patterns were assessed before and after locomotor training. The soleus H reflexes evoked at 1.0, 0.33, 0.20, 0.14, and 0.11 Hz were normalized to the H reflex evoked at 0.09 Hz. Conditioned H reflexes were normalized to the associated unconditioned H reflex evoked with subjects seated, while during stepping both H reflexes were normalized to the maximal M wave evoked after the test H reflex at each bin of the step cycle. Locomotor training potentiated homosynaptic depression in all participants regardless the type of the SCI. Presynaptic facilitation of soleus Ia afferents remained unaltered in motor complete SCI patients. In motor incomplete SCIs, locomotor training either reduced presynaptic facilitation or replaced presynaptic facilitation with presynaptic inhibition at rest. During stepping, presynaptic inhibition was modulated in a phase-dependent manner. Locomotor training changed the amplitude of locomotor EMG excitability, promoted intralimb and interlimb coordination, and altered cocontraction between knee and ankle antagonistic muscles differently in the more impaired leg compared with the less impaired leg. The results provide strong evidence that locomotor training improves premotoneuronal control after SCI in humans at rest and during walking. Copyright © 2014 the American Physiological Society.

The Exploration of Design Driven Innovation as a Dynamic Capability

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Philips Kembaren

2012-01-01

Full Text Available Innovation enables companies to attain consistent organic growth that brings benefits to stakeholders. Designthinking approach in innovation has been emergent to be an alternative to technological development path inorder to generate competitive and successful product or service in the market place. Design driven innovationcombines functional and semantic dimensions of products or services in the marketplace. Previous researchhas recently revealed practices of design driven innovation in various industries. However, little is known tothe extent that companies in Indonesia practicing design driven innovation. A theoretical framework withperspective from dynamic capability theoretical lens and guided by Dubin’s theory building methodology isproposed to explain the constructs and role of design in the process of innovation. The research is expected tocontribute a new construct to the existing framework, namely construct that related to how we could assessthe value of the design-driven innovation output, perceived by the costumers.Keywords: design driven innovation, dynamic capabilities, theory building

Footwear and locomotor skill performance in preschoolers.

Science.gov (United States)

Robinson, Leah E; Rudisill, Mary E; Weimar, Wendi H; Breslin, Casey M; Shroyer, Justin F; Morera, Maria

2011-10-01

The effect of footwear on locomotor skill performance was examined. 12 children (4 boys, 8 girls; M age = 56.3 mo., SD = 3.3) served as participants. Participants were randomly assigned to perform the locomotor subscale of Ulrich's Test of Gross Motor Development in two shoe conditions (Condition 1: Stride Rite athletic shoes, and Condition 2: flip flop sandals). Children scored significantly higher when wearing athletic shoes than flip-flop sandals. This finding is relevant for motor performance and safety in physical education and movement programs.

The anatomy and physiology of the locomotor system.

Science.gov (United States)

Farley, Alistair; McLafferty, Ella; Hendry, Charles

Mobilisation is one of the activities of living. The term locomotor system refers to those body tissues and organs responsible for movement. Nurses and healthcare workers should be familiar with the body structures that enable mobilisation to assist those in their care with this activity. This article outlines the structure and function of the locomotor system, including the skeleton, joints, muscles and muscle attachments. Two common bone disorders, osteoporosis and osteoarthritis, are also considered.

Does the Size Matter for Dynamics Capabilities? A Study on Absorptive Capacity

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Marlon Fernandes Rodrigues Alves

2016-10-01

Full Text Available The objective of this study is to understand how organizational size influences dynamic capabilities in Brazil. To arrive at this understanding, structural equation modeling analysis was performed using the Brazilian Innovation Survey (PINTEC database to test for differences between SMEs and large companies in respect to the relationship between absorptive capacity (AC dimensions and innovation performance. The results show that in large companies, Potential AC and Realized AC impact innovation performance, whereas in small and medium-sized enterprises (SMEs, only Realized AC has an influence. In addition, SMEs are, in fact, better at converting Realized AC into innovation performance than large companies, probably due to their flexibility and agility. These findings reveal that organizational sizes influence the impact of dynamic capabilities on performance.

Effects of caffeine on locomotor activity in streptozotocin-induced diabetic rats.

Science.gov (United States)

Bădescu, S V; Tătaru, C P; Kobylinska, L; Georgescu, E L; Zahiu, D M; Zăgrean, A M; Zăgrean, L

2016-01-01

Diabetes mellitus modifies the expression of adenosine receptors in the brain. Caffeine acts as an antagonist of A1 and A2A adenosine receptors and was shown to have a dose-dependent biphasic effect on locomotion in mice. The present study investigated the link between diabetes and locomotor activity in an animal model of streptozotocin-induced diabetes, and the effects of a low-medium dose of caffeine in this relation. The locomotor activity was investigated by using Open Field Test at 6 weeks after diabetes induction and after 2 more weeks of chronic caffeine administration. Diabetes decreased locomotor activity (total distance moved and mobility time). Chronic caffeine exposure impaired the locomotor activity in control rats, but not in diabetic rats. Our data suggested that the medium doses of caffeine might block the A2A receptors, shown to have an increased density in the brain of diabetic rats, and improve or at least maintain the locomotor activity, offering a neuroprotective support in diabetic rats. Abbreviations : STZ = streptozotocin, OFT = Open Field Test.

Sex differences in the acute locomotor response to methamphetamine in BALB/c mice.

Science.gov (United States)

Ohia-Nwoko, Odochi; Haile, Colin N; Kosten, Therese A

2017-06-01

Women use methamphetamine more frequently than men and are more vulnerable to its negative psychological effects. Rodent models have been an essential tool for evaluating the sex-dependent effects of psychostimulants; however, evidence of sex differences in the behavioral responses to methamphetamine in mice is lacking. In the present study, we investigated acute methamphetamine-induced (1mg/kg and 4mg/kg) locomotor activation in female and male BALB/c mice. We also evaluated whether basal locomotor activity was associated with the methamphetamine-induced locomotor response. The results indicated that female BALB/c mice displayed enhanced methamphetamine-induced locomotor activity compared to males, while basal locomotor activity was positively correlated with methamphetamine-induced activity in males, but not females. This study is the first to show sex-dependent locomotor effects of methamphetamine in BALB/c mice. Our observations emphasize the importance of considering sex when assessing behavioral responses to methamphetamine. Copyright © 2017 Elsevier B.V. All rights reserved.

Capabilities for Strategic Adaptation

DEFF Research Database (Denmark)

Distel, Andreas Philipp

This dissertation explores capabilities that enable firms to strategically adapt to environmental changes and preserve competitiveness over time – often referred to as dynamic capabilities. While dynamic capabilities being a popular research domain, too little is known about what these capabiliti...

Limitations to the Generality of Cocaine Locomotor Sensitization

OpenAIRE

Marusich, Julie A.; Branch, Marc N.; Dallery, Jesse

2008-01-01

Repeated exposure to cocaine often leads to tolerance to effects on operant behavior, whereas sensitization often develops to effects on locomotor activity. The purpose of the present set of experiments was to examine if locomotor sensitization to cocaine would develop in the presence or absence of an operant contingency in rats. In Experiment 1, rats lever pressed on an FR schedule of reinforcement, and were administered chronic cocaine. Tolerance to effects of cocaine on lever pressing deve...

High Throughput Measurement of Locomotor Sensitization to Volatilized Cocaine in Drosophila melanogaster.

Science.gov (United States)

Filošević, Ana; Al-Samarai, Sabina; Andretić Waldowski, Rozi

2018-01-01

Drosophila melanogaster can be used to identify genes with novel functional roles in neuronal plasticity induced by repeated consumption of addictive drugs. Behavioral sensitization is a relatively simple behavioral output of plastic changes that occur in the brain after repeated exposures to drugs of abuse. The development of screening procedures for genes that control behavioral sensitization has stalled due to a lack of high-throughput behavioral tests that can be used in genetically tractable organism, such as Drosophila . We have developed a new behavioral test, FlyBong, which combines delivery of volatilized cocaine (vCOC) to individually housed flies with objective quantification of their locomotor activity. There are two main advantages of FlyBong: it is high-throughput and it allows for comparisons of locomotor activity of individual flies before and after single or multiple exposures. At the population level, exposure to vCOC leads to transient and concentration-dependent increase in locomotor activity, representing sensitivity to an acute dose. A second exposure leads to further increase in locomotion, representing locomotor sensitization. We validate FlyBong by showing that locomotor sensitization at either the population or individual level is absent in the mutants for circadian genes period (per) , Clock (Clk) , and cycle (cyc) . The locomotor sensitization that is present in timeless (tim) and pigment dispersing factor (pdf) mutant flies is in large part not cocaine specific, but derived from increased sensitivity to warm air. Circadian genes are not only integral part of the neural mechanism that is required for development of locomotor sensitization, but in addition, they modulate the intensity of locomotor sensitization as a function of the time of day. Motor-activating effects of cocaine are sexually dimorphic and require a functional dopaminergic transporter. FlyBong is a new and improved method for inducing and measuring locomotor sensitization

High Throughput Measurement of Locomotor Sensitization to Volatilized Cocaine in Drosophila melanogaster

Directory of Open Access Journals (Sweden)

Ana Filošević

2018-02-01

Full Text Available Drosophila melanogaster can be used to identify genes with novel functional roles in neuronal plasticity induced by repeated consumption of addictive drugs. Behavioral sensitization is a relatively simple behavioral output of plastic changes that occur in the brain after repeated exposures to drugs of abuse. The development of screening procedures for genes that control behavioral sensitization has stalled due to a lack of high-throughput behavioral tests that can be used in genetically tractable organism, such as Drosophila. We have developed a new behavioral test, FlyBong, which combines delivery of volatilized cocaine (vCOC to individually housed flies with objective quantification of their locomotor activity. There are two main advantages of FlyBong: it is high-throughput and it allows for comparisons of locomotor activity of individual flies before and after single or multiple exposures. At the population level, exposure to vCOC leads to transient and concentration-dependent increase in locomotor activity, representing sensitivity to an acute dose. A second exposure leads to further increase in locomotion, representing locomotor sensitization. We validate FlyBong by showing that locomotor sensitization at either the population or individual level is absent in the mutants for circadian genes period (per, Clock (Clk, and cycle (cyc. The locomotor sensitization that is present in timeless (tim and pigment dispersing factor (pdf mutant flies is in large part not cocaine specific, but derived from increased sensitivity to warm air. Circadian genes are not only integral part of the neural mechanism that is required for development of locomotor sensitization, but in addition, they modulate the intensity of locomotor sensitization as a function of the time of day. Motor-activating effects of cocaine are sexually dimorphic and require a functional dopaminergic transporter. FlyBong is a new and improved method for inducing and measuring locomotor

Locomotor problems among rural elderly population in a District of Aligarh, North India.

Science.gov (United States)

Maroof, Mohd; Ahmad, Anees; Khalique, Najam; Ansari, M Athar

2017-01-01

Locomotor functions decline with the age along with other physiological changes. This results in deterioration of the quality of life with decreased social and economic role in the society, as well as increased dependency, for the health care and other basic services. The demographic transition resulting in increased proportion of elderly may pose a burden to the health system. To find the prevalence of locomotor problems among the elderly population, and related sociodemographic factors. The study was a community-based cross-sectional study done at field practice area of Rural Health Training Centre, JN Medical College, AMU, Aligarh, Uttar Pradesh, India. A sample of 225 was drawn from 1018 elderly population aged 60 years and above using systematic random sampling with probability proportionate to size. Sociodemographic characteristics were obtained using pretested and predesigned questionnaire. Locomotor problems were assessed using the criteria used by National Sample Survey Organization. Data were analyzed using SPSS version 20. Chi-square test was used to test relationship of locomotor problems with sociodemographic factors. P locomotor problems among the elderly population was 25.8%. Locomotor problems were significantly associated with age, gender, and working status whereas no significant association with literacy status and marital status was observed. The study concluded that approximately one-fourth of the elderly population suffered from locomotor problems. The sociodemographic factors related to locomotor problems needs to be addressed properly to help them lead an independent and economically productive life.

An Integrated Gait and Balance Analysis System to Define Human Locomotor Control

Science.gov (United States)

2016-04-29

test hypotheses they developed about how people walk. An Integrated Gait and Balance Analysis System to define Human Locomotor Control W911NF-14-R-0009...An Integrated Gait and Balance Analysis System to Define Human Locomotor Control Walking is a complicated task that requires the motor coordination...Gait and Balance Analysis System to Define Human Locomotor Control Report Title Walking is a complicated task that requires the motor coordination across

Anatomía del Aparato Locomotor, 2010-11

OpenAIRE

Juanes Méndez, Juan Antonio

2010-01-01

I. Materiales de clase: 1.Sistema Oseo. Las Articulaciones: definición, clasificaciones; 2.Esqueleto Axial; 3.Esqueleto Apendicular; 4. Organización del sistema nervioso periférico. Inervación del Aparato Locomotor; 5. Sistema muscular. II. Bibliografía y atlas Establecer la correlación morfofuncional del aparato locomotor necesaria para la deducción deficitaria derivada de las alteraciones de la dinámica osteoarticular. Esta asignatura se imparte en el primer curso del Grado en Terapia Oc...

Using Tests Designed to Measure Individual Sensorimotor Subsystem Perfomance to Predict Locomotor Adaptability

Science.gov (United States)

Peters, B. T.; Caldwell, E. E.; Batson, C. D.; Guined, J. R.; DeDios, Y. E.; Stepanyan, V.; Gadd, N. E.; Szecsy, D. L.; Mulavara, A. P.; Seidler, R. D.;

[The formation of the self-maintenance skills in the pre-school children presenting with locomotor and coordination disorders].

Science.gov (United States)

Poletaeva-Dubrovina, N A; Burkova, A M

2016-01-01

The Ministry of Health of the Russian Federation acknowledges the sharp rise in the prevalence of congenital malformation in this country during the past 30 years. In 2010-2011, this pathology was estimated to occur in 3% of the children. It includes a variety of locomotor and coordination disorders of which the most widespread are infantile cerebral paralysis, ataxia, consequences of perinatal lesions of the central nervous system, etc. This article contains a detailed description of these locomotor and coordination disorders. The objective of the present work was to elaborate and evaluate the program for the formation of the self-maintenance skills in the pre-school children presenting with locomotor and coordination disorders under conditions of family guidance and education. The study was carried out from September 2013 till May 2014 based at MUP DOD "Semeiny klub Nadezhda" ("The Hope Family Club", Municipal unitary facility for children's additional education) and supported by B.N. El'tsin Ural Federal University. It included 10 children suffering from locomotor and coordination disorders of different severity and members of their families. The following methods were used: the self-service skills scorecard , monitoring formation of the motor skills, and Wilcoxon's T-test. The use of the program based on the cooperation with the children's families allowed to achieve positive dynamics in the patients' conditions. Moreover, 30% of them acquired the full scope of the self-maintenance skills. The most pronounced changes in the motor abilities were apparent in the movements of the upper and lower extremitis, walking, and motion in space. The proposed program for the formation of the self-maintenance skills in the pre-school children presenting with locomotor and coordination disorders proved to be highly efficacious. The study has demonstrated the importance of the parents' involvement in the process of formation of the self-maintenance skills and motor abilities

A stochastic locomotor control model for the nurse shark, Ginglymostoma cirratum.

Science.gov (United States)

Gerald, K B; Matis, J H; Kleerekoper, H

1978-06-12

The locomotor behavior of the nurse shark (Ginglymostoma cirratum) is characterized by 17 variables (frequency and ratios of left, right, and total turns; their radians; straight paths (steps); distance travelled; and velocity) Within each of these variables there is an internal time dependency the structure of which was elaborated together with an improved statistical model predicting their behavior within 90% confidence limits. The model allows for the sensitive detection of subtle locomotor response to sensory stimulation as values of variables may exceed the established confidence limits within minutes after onset of the stimulus. The locomotor activity is well described by an autoregression time series model and can be predicted by only seven variables. Six of these form two independently operating clusters. The first one consists of: the number of right turns, the distance travelled and the mean velocity; the second one of: the mean size of right turns, of left turns, and of all turns. The same clustering is obtained independently by a cluster analysis of cross-sections of the seven time series. It is apparent that, among a total of 17 locomotor variables, seven behave as individually independent agents, presumably controlled by seven separate and independent centers. The output of each center can only be predicted by its own behavior. In spite of the individual of the seven variables, their internal structure is similar in important aspects which may result from control by a common command center. The shark locomotor model differs in important aspects from the previously constructed for the goldfish. The interdependence of the locomotor variables in both species may be related to the control mechanisms postulated by von Holst for the coordination of rhythmic fin movements in fishes. A locomotor control model for the nurse shark is proposed.

Acetylcholinesterase inhibition and altered locomotor behavior in the carabid beetle pterostichus

DEFF Research Database (Denmark)

Jensen, Charlotte S.; Krause-Jensen, Lone; Baatrup, Erik

1997-01-01

-aided video tracking, whereupon the whole body AChE activity was measured in the individual beetle. AChE inhibition was strongly correlated with dimethoate dose in both sexes. Alterations in the locomotor behavior were directly correlated with AChE inhibition in male beetles, which responded by reducing...... to locomotor behavior, representing a general effect biomarker at the organismal level. Both sexes of the carabid beetle Pterostichus cupreus were intoxicated with three doses of the organophosphorous insecticide dimethoate. Five elements of their locomotor behavior were measured for 4 h employing computer...... the time in locomotion, average velocity, and path length and by increasing the turning rate and frequency of stops. Females responded similarly at the two highest doses, whereas their locomotor behavior was not significantly different from the control group at the lowest dimethoate dose, suggesting a sex...

Oxytocin decreases cocaine taking, cocaine seeking, and locomotor activity in female rats.

Science.gov (United States)

Leong, Kah-Chung; Zhou, Luyi; Ghee, Shannon M; See, Ronald E; Reichel, Carmela M

2016-02-01

Oxytocin has been shown to decrease cocaine taking and seeking in male rats, suggesting potential treatment efficacy for drug addiction. In the present study, we extended these findings to the assessment of cocaine seeking and taking in female rats. Further, we made direct comparisons of oxytocin's impact on cocaine induced locomotor activity in both males and females. In females, systemic oxytocin (0.3, 1.0, 3.0 mg/kg) attenuated lever pressing for cocaine during self-administration and oxytocin (1.0 mg/kg) attenuated cue-induced cocaine seeking following extinction. Cocaine increased baseline locomotor activity to a greater degree in females relative to males. Oxytocin (0.1, 0.3, 1.0, and 3.0 mg/kg) reduced cocaine-induced locomotor activity in females, but not significantly in males. These data illustrate sex similarities in oxytocin's attenuation of cocaine seeking, but sex differences in cocaine-induced locomotor effects. While reductions in cocaine seeking cannot be attributed to a reduction in locomotor activity in males, attenuation of locomotor function cannot be entirely ruled out as an explanation for a decrease in cocaine seeking in females suggesting that oxytocin's effect on cocaine seeking may be mediated by different mechanisms in male and females. PsycINFO Database Record (c) 2016 APA, all rights reserved.

Modular Diversification of the Locomotor System in Damselfishes (Pomacentridae)

OpenAIRE

Aguilar-Medrano, Rosalia; Frederich, Bruno; Barber, Paul H.

2016-01-01

As fish move and interact with their aquatic environment by swimming, small morphological variations of the locomotor system can have profound implications on fitness. Damselfishes (Pomacentridae) have inhabited coral reef ecosystems for more than 50 million years. As such, habitat preferences and behavior could significantly constrain the morphology and evolvability of the locomotor system. To test this hypothesis, we used phylogenetic comparative methods on morphometric, ecological and beha...

Optic flow improves adaptability of spatiotemporal characteristics during split-belt locomotor adaptation with tactile stimulation

OpenAIRE

Anthony Eikema, Diderik Jan A.; Chien, Jung Hung; Stergiou, Nicholas; Myers, Sara A.; Scott-Pandorf, Melissa M.; Bloomberg, Jacob J.; Mukherjee, Mukul

2015-01-01

Human locomotor adaptation requires feedback and feed-forward control processes to maintain an appropriate walking pattern. Adaptation may require the use of visual and proprioceptive input to decode altered movement dynamics and generate an appropriate response. After a person transfers from an extreme sensory environment and back, as astronauts do when they return from spaceflight, the prolonged period required for re-adaptation can pose a significant burden. In our previous paper, we showe...

Human neural stem cells differentiate and promote locomotor recovery in an early chronic spinal cord injury NOD-scid mouse model.

Directory of Open Access Journals (Sweden)

Desirée L Salazar

2010-08-01

Full Text Available Traumatic spinal cord injury (SCI results in partial or complete paralysis and is characterized by a loss of neurons and oligodendrocytes, axonal injury, and demyelination/dysmyelination of spared axons. Approximately 1,250,000 individuals have chronic SCI in the U.S.; therefore treatment in the chronic stages is highly clinically relevant. Human neural stem cells (hCNS-SCns were prospectively isolated based on fluorescence-activated cell sorting for a CD133(+ and CD24(-/lo population from fetal brain, grown as neurospheres, and lineage restricted to generate neurons, oligodendrocytes and astrocytes. hCNS-SCns have recently been transplanted sub-acutely following spinal cord injury and found to promote improved locomotor recovery. We tested the ability of hCNS-SCns transplanted 30 days post SCI to survive, differentiate, migrate, and promote improved locomotor recovery.hCNS-SCns were transplanted into immunodeficient NOD-scid mice 30 days post spinal cord contusion injury. hCNS-SCns transplanted mice demonstrated significantly improved locomotor recovery compared to vehicle controls using open field locomotor testing and CatWalk gait analysis. Transplanted hCNS-SCns exhibited long-term engraftment, migration, limited proliferation, and differentiation predominantly to oligodendrocytes and neurons. Astrocytic differentiation was rare and mice did not exhibit mechanical allodynia. Furthermore, differentiated hCNS-SCns integrated with the host as demonstrated by co-localization of human cytoplasm with discrete staining for the paranodal marker contactin-associated protein.The results suggest that hCNS-SCns are capable of surviving, differentiating, and promoting improved locomotor recovery when transplanted into an early chronic injury microenvironment. These data suggest that hCNS-SCns transplantation has efficacy in an early chronic SCI setting and thus expands the "window of opportunity" for intervention.

Effect of thermal acclimation on locomotor energetics and locomotor performance in a lungless salamander, Desmognathus ochrophaeus.

Science.gov (United States)

Feder, M E

1986-03-01

To determine the effects of thermal acclimation upon locomotor performance and the rate of oxygen consumption (MO2) during activity, small (less than 3 g), lungless salamanders, Desmognathus ochrophaeus Cope, were acclimated to three temperatures (5, 13 and 21 degrees C) and exercised at various controlled speeds within an exercise wheel while their MO2 was measured. MO2 increased with speed at low speeds (less than 14 cm min-1). Although animals could sustain greater speeds, MO2 did not increase further. These small, exclusively skin-breathing salamanders could increase their MO2 9-11 times during exercise and could sustain nearly half of the oxygen flux expected across a similar surface area of the mammalian lung. However, their maximum aerobic speed was remarkably slow (14 cm min-1) and their net cost of transport remarkably large (15-17 ml O2 g-1 km-1). Thermal acclimation affected MO2 during activity, the maximum sustainable speed and locomotor stamina in different ways. During exercise at 13 degrees C, cold-acclimated animals had a significantly greater MO2 than warm-acclimated animals, but did not differ in stamina or the maximum sustainable speed. During exercise at 21 degrees C, cold acclimation did not affect the MO2 significantly, but it decreased the stamina and increased the rate of lactate accumulation. Thus, these results suggest that thermal acclimation of the MO2 is not tightly coupled to thermal acclimation of locomotor performance in salamanders.

Locomotor Sub-functions for Control of Assistive Wearable Robots

Directory of Open Access Journals (Sweden)

Maziar A. Sharbafi

2017-09-01

Full Text Available A primary goal of comparative biomechanics is to understand the fundamental physics of locomotion within an evolutionary context. Such an understanding of legged locomotion results in a transition from copying nature to borrowing strategies for interacting with the physical world regarding design and control of bio-inspired legged robots or robotic assistive devices. Inspired from nature, legged locomotion can be composed of three locomotor sub-functions, which are intrinsically interrelated: Stance: redirecting the center of mass by exerting forces on the ground. Swing: cycling the legs between ground contacts. Balance: maintaining body posture. With these three sub-functions, one can understand, design and control legged locomotory systems with formulating them in simpler separated tasks. Coordination between locomotor sub-functions in a harmonized manner appears then as an additional problem when considering legged locomotion. However, biological locomotion shows that appropriate design and control of each sub-function simplifies coordination. It means that only limited exchange of sensory information between the different locomotor sub-function controllers is required enabling the envisioned modular architecture of the locomotion control system. In this paper, we present different studies on implementing different locomotor sub-function controllers on models, robots, and an exoskeleton in addition to demonstrating their abilities in explaining humans' control strategies.

Locomotor Sub-functions for Control of Assistive Wearable Robots.

Science.gov (United States)

Sharbafi, Maziar A; Seyfarth, Andre; Zhao, Guoping

2017-01-01

A primary goal of comparative biomechanics is to understand the fundamental physics of locomotion within an evolutionary context. Such an understanding of legged locomotion results in a transition from copying nature to borrowing strategies for interacting with the physical world regarding design and control of bio-inspired legged robots or robotic assistive devices. Inspired from nature, legged locomotion can be composed of three locomotor sub-functions, which are intrinsically interrelated: Stance : redirecting the center of mass by exerting forces on the ground. Swing : cycling the legs between ground contacts. Balance : maintaining body posture. With these three sub-functions, one can understand, design and control legged locomotory systems with formulating them in simpler separated tasks. Coordination between locomotor sub-functions in a harmonized manner appears then as an additional problem when considering legged locomotion. However, biological locomotion shows that appropriate design and control of each sub-function simplifies coordination. It means that only limited exchange of sensory information between the different locomotor sub-function controllers is required enabling the envisioned modular architecture of the locomotion control system. In this paper, we present different studies on implementing different locomotor sub-function controllers on models, robots, and an exoskeleton in addition to demonstrating their abilities in explaining humans' control strategies.

The ventromedial hypothalamus oxytocin induces locomotor behavior regulated by estrogen.

Science.gov (United States)

Narita, Kazumi; Murata, Takuya; Matsuoka, Satoshi

2016-10-01

Our previous studies demonstrated that excitation of neurons in the rat ventromedial hypothalamus (VMH) induced locomotor activity. An oxytocin receptor (Oxtr) exists in the VMH and plays a role in regulating sexual behavior. However, the role of Oxtr in the VMH in locomotor activity is not clear. In this study we examined the roles of oxytocin in the VMH in running behavior, and also investigated the involvement of estrogen in this behavioral change. Microinjection of oxytocin into the VMH induced a dose-dependent increase in the running behavior in male rats. The oxytocin-induced running activity was inhibited by simultaneous injection of Oxtr-antagonist, (d(CH2)5(1), Try(Me)(2), Orn(8))-oxytocin. Oxytocin injection also induced running behavior in ovariectomized (OVX) female rats. Pretreatment of the OVX rats with estrogen augmented the oxytocin-induced running activity twofold, and increased the Oxtr mRNA in the VMH threefold. During the estrus cycle locomotor activity spontaneously increased in the dark period of proestrus. The Oxtr mRNA was up-regulated in the proestrus afternoon. Blockade of oxytocin neurotransmission by its antagonist before the onset of the dark period of proestrus decreased the following nocturnal locomotor activity. These findings demonstrate that Oxtr in the VMH is involved in the induction of running behavior and that estrogen facilitates this effect by means of Oxtr up-regulation, suggesting the involvement of oxytocin in the locomotor activity of proestrus female rats. Copyright © 2016 Elsevier Inc. All rights reserved.

Building Dynamic Capabilities in Web Startups: An Empirical Study of Norwegian Web Startups

OpenAIRE

Sahlen, Martin Abelson; Gran-Jansen, Sigurd; Rygh, Mathias

2014-01-01

Purpose: This thesis explores how web startups operating in a crowded, fast-moving and highly competitive marketplace can gain competitive advantage through building dynamic capabilities and what these capabilities consist of. Design/methodology/approach: Firstly, insight was obtained through reviewing key themes within classic resource based theory and entrepreneurship theory. Newer empirical research on entrepreneurial success factors, as well as popular science and advice given by expert w...

Comparative limb proportions reveal differential locomotor morphofunctions of alligatoroids and crocodyloids

Science.gov (United States)

Iijima, Masaya; Kubo, Tai; Kobayashi, Yoshitsugu

2018-03-01

Although two major clades of crocodylians (Alligatoroidea and Crocodyloidea) were split during the Cretaceous period, relatively few morphological and functional differences between them have been known. In addition, interaction of multiple morphofunctional systems that differentiated their ecology has barely been assessed. In this study, we examined the limb proportions of crocodylians to infer the differences of locomotor functions between alligatoroids and crocodyloids, and tested the correlation of locomotor and feeding morphofunctions. Our analyses revealed crocodyloids including Gavialis have longer stylopodia (humerus and femur) than alligatoroids, indicating that two groups may differ in locomotor functions. Fossil evidence suggested that alligatoroids have retained short stylopodia since the early stage of their evolution. Furthermore, rostral shape, an indicator of trophic function, is correlated with limb proportions, where slender-snouted piscivorous taxa have relatively long stylopodia and short overall limbs. In combination, trophic and locomotor functions might differently delimit the ecological opportunity of alligatoroids and crocodyloids in the evolution of crocodylians.

Dynamic Resource Allocation and QoS Control Capabilities of the Japanese Academic Backbone Network

Directory of Open Access Journals (Sweden)

Michihiro Aoki

2010-08-01

Full Text Available Dynamic resource control capabilities have become increasingly important for academic networks that must support big scientific research projects at the same time as less data intensive research and educational activities. This paper describes the dynamic resource allocation and QoS control capabilities of the Japanese academic backbone network, called SINET3, which supports a variety of academic applications with a wide range of network services. The article describes the network architecture, networking technologies, resource allocation, QoS control, and layer-1 bandwidth on-demand services. It also details typical services developed for scientific research, including the user interface, resource control, and management functions, and includes performance evaluations.

Neuromodulation of the lumbar spinal locomotor circuit.

Science.gov (United States)

AuYong, Nicholas; Lu, Daniel C

2014-01-01

The lumbar spinal cord contains the necessary circuitry to independently drive locomotor behaviors. This function is retained following spinal cord injury (SCI) and is amenable to rehabilitation. Although the effectiveness of task-specific training and pharmacologic modulation has been repeatedly demonstrated in animal studies, results from human studies are less striking. Recently, lumbar epidural stimulation (EDS) along with locomotor training was shown to restore weight-bearing function and lower-extremity voluntary control in a chronic, motor-complete human SCI subject. Related animal studies incorporating EDS as part of the therapeutic regiment are also encouraging. EDS is emerging as a promising neuromodulatory tool for SCI. Copyright © 2014 Elsevier Inc. All rights reserved.

V3 spinal neurons establish a robust and balanced locomotor rhythm during walking.

Science.gov (United States)

Zhang, Ying; Narayan, Sujatha; Geiman, Eric; Lanuza, Guillermo M; Velasquez, Tomoko; Shanks, Bayle; Akay, Turgay; Dyck, Jason; Pearson, Keir; Gosgnach, Simon; Fan, Chen-Ming; Goulding, Martyn

2008-10-09

A robust and well-organized rhythm is a key feature of many neuronal networks, including those that regulate essential behaviors such as circadian rhythmogenesis, breathing, and locomotion. Here we show that excitatory V3-derived neurons are necessary for a robust and organized locomotor rhythm during walking. When V3-mediated neurotransmission is selectively blocked by the expression of the tetanus toxin light chain subunit (TeNT), the regularity and robustness of the locomotor rhythm is severely perturbed. A similar degeneration in the locomotor rhythm occurs when the excitability of V3-derived neurons is reduced acutely by ligand-induced activation of the allatostatin receptor. The V3-derived neurons additionally function to balance the locomotor output between both halves of the spinal cord, thereby ensuring a symmetrical pattern of locomotor activity during walking. We propose that the V3 neurons establish a regular and balanced motor rhythm by distributing excitatory drive between both halves of the spinal cord.

Interpreting locomotor biomechanics from the morphology of human footprints.

Science.gov (United States)

Hatala, Kevin G; Wunderlich, Roshna E; Dingwall, Heather L; Richmond, Brian G

2016-01-01

Fossil hominin footprints offer unique direct windows to the locomotor behaviors of our ancestors. These data could allow a clearer understanding of the evolution of human locomotion by circumventing issues associated with indirect interpretations of habitual locomotor patterns from fossil skeletal material. However, before we can use fossil hominin footprints to understand better the evolution of human locomotion, we must first develop an understanding of how locomotor biomechanics are preserved in, and can be inferred from, footprint morphologies. In this experimental study, 41 habitually barefoot modern humans created footprints under controlled conditions in which variables related to locomotor biomechanics could be quantified. Measurements of regional topography (depth) were taken from 3D models of those footprints, and principal components analysis was used to identify orthogonal axes that described the largest proportions of topographic variance within the human experimental sample. Linear mixed effects models were used to quantify the influences of biomechanical variables on the first five principal axes of footprint topographic variation, thus providing new information on the biomechanical variables most evidently expressed in the morphology of human footprints. The footprint's overall depth was considered as a confounding variable, since biomechanics may be linked to the extent to which a substrate deforms. Three of five axes showed statistically significant relationships with variables related to both locomotor biomechanics and substrate displacement; one axis was influenced only by biomechanics and another only by the overall depth of the footprint. Principal axes of footprint morphological variation were significantly related to gait type (walking or running), kinematics of the hip and ankle joints and the distribution of pressure beneath the foot. These results provide the first quantitative framework for developing hypotheses regarding the

Cocaine locomotor activation, sensitization and place preference in six inbred strains of mice

Science.gov (United States)

2011-01-01

Background The expanding set of genomics tools available for inbred mouse strains has renewed interest in phenotyping larger sets of strains. The present study aims to explore phenotypic variability among six commonly-used inbred mouse strains to both the rewarding and locomotor stimulating effects of cocaine in a place conditioning task, including several strains or substrains that have not yet been characterized for some or all of these behaviors. Methods C57BL/6J (B6), BALB/cJ (BALB), C3H/HeJ (C3H), DBA/2J (D2), FVB/NJ (FVB) and 129S1/SvImJ (129) mice were tested for conditioned place preference to 20 mg/kg cocaine. Results Place preference was observed in most strains with the exception of D2 and 129. All strains showed a marked increase in locomotor activity in response to cocaine. In BALB mice, however, locomotor activation was context-dependent. Locomotor sensitization to repeated exposure to cocaine was most significant in 129 and D2 mice but was absent in FVB mice. Conclusions Genetic correlations suggest that no significant correlation between conditioned place preference, acute locomotor activation, and locomotor sensitization exists among these strains indicating that separate mechanisms underlie the psychomotor and rewarding effects of cocaine. PMID:21806802

Quaternary naltrexone reverses radiogenic and morphine-induced locomotor hyperactivity

Energy Technology Data Exchange (ETDEWEB)

Mickley, G.A.; Stevens, K.E.; Galbraith, J.A.; White, G.A.; Gibbs, G.L.

1984-04-01

The present study attempted to determine the relative role of the peripheral and central nervous system in the production of morphine-induced or radiation-induced locomotor hyperactivity of the mouse. Toward this end, we used a quaternary derivative of an opiate antagonist (naltrexone methobromide), which presumably does not cross the blood-brain barrier. Quaternary naltrexone was used to challenge the stereotypic locomotor response observed in these mice after either an i.p. injection of morphine or exposure to 1500 rads /sup 60/Co. The quaternary derivative of naltrexone reversed the locomotor hyperactivity normally observed in the C57BL/6J mouse after an injection of morphine. It also significantly attenuated radiation-induced locomotion. The data reported here support the hypothesis of endorphin involvement in radiation-induced and radiogenic behaviors. However, these conclusions are contingent upon further research which more fully evaluates naltrexone methobromide's capacity to cross the blood-brain barrier.

Delineating the Diversity of Spinal Interneurons in Locomotor Circuits.

Science.gov (United States)

Gosgnach, Simon; Bikoff, Jay B; Dougherty, Kimberly J; El Manira, Abdeljabbar; Lanuza, Guillermo M; Zhang, Ying

2017-11-08

Locomotion is common to all animals and is essential for survival. Neural circuits located in the spinal cord have been shown to be necessary and sufficient for the generation and control of the basic locomotor rhythm by activating muscles on either side of the body in a specific sequence. Activity in these neural circuits determines the speed, gait pattern, and direction of movement, so the specific locomotor pattern generated relies on the diversity of the neurons within spinal locomotor circuits. Here, we review findings demonstrating that developmental genetics can be used to identify populations of neurons that comprise these circuits and focus on recent work indicating that many of these populations can be further subdivided into distinct subtypes, with each likely to play complementary functions during locomotion. Finally, we discuss data describing the manner in which these populations interact with each other to produce efficient, task-dependent locomotion. Copyright © 2017 the authors 0270-6474/17/3710835-07$15.00/0.

Visual and kinesthetic locomotor imagery training integrated with auditory step rhythm for walking performance of patients with chronic stroke.

Science.gov (United States)

Kim, Jin-Seop; Oh, Duck-Won; Kim, Suhn-Yeop; Choi, Jong-Duk

2011-02-01

To compare the effect of visual and kinesthetic locomotor imagery training on walking performance and to determine the clinical feasibility of incorporating auditory step rhythm into the training. Randomized crossover trial. Laboratory of a Department of Physical Therapy. Fifteen subjects with post-stroke hemiparesis. Four locomotor imagery trainings on walking performance: visual locomotor imagery training, kinesthetic locomotor imagery training, visual locomotor imagery training with auditory step rhythm and kinesthetic locomotor imagery training with auditory step rhythm. The timed up-and-go test and electromyographic and kinematic analyses of the affected lower limb during one gait cycle. After the interventions, significant differences were found in the timed up-and-go test results between the visual locomotor imagery training (25.69 ± 16.16 to 23.97 ± 14.30) and the kinesthetic locomotor imagery training with auditory step rhythm (22.68 ± 12.35 to 15.77 ± 8.58) (P kinesthetic locomotor imagery training exhibited significantly increased activation in a greater number of muscles and increased angular displacement of the knee and ankle joints compared with the visual locomotor imagery training, and these effects were more prominent when auditory step rhythm was integrated into each form of locomotor imagery training. The activation of the hamstring during the swing phase and the gastrocnemius during the stance phase, as well as kinematic data of the knee joint, were significantly different for posttest values between the visual locomotor imagery training and the kinesthetic locomotor imagery training with auditory step rhythm (P kinesthetic locomotor imagery training than in the visual locomotor imagery training. The auditory step rhythm together with the locomotor imagery training produces a greater positive effect in improving the walking performance of patients with post-stroke hemiparesis.

Technological Dynamics and Social Capability

DEFF Research Database (Denmark)

Fagerberg, Jan; Feldman, Maryann; Srholec, Martin

2014-01-01

for the sample as a whole between 1998 and 2008. The results indicate that social capabilities, such as well-developed public knowledge infrastructure, an egalitarian distribution of income, a participatory democracy and prevalence of public safety condition the growth of technological capabilities. Possible...

Developing the content of a locomotor disability scale for adults in Bangladesh: a qualitative study.

Science.gov (United States)

Mahmud, Ilias; Clarke, Lynda; Ploubidis, George B

2017-01-01

Bangladesh has an estimated 17 million adults with disabilities. A significant proportion of them are believed to have locomotor disabilities. There are over 300 non-governmental organizations providing different types of rehabilitation services to them. However, there is no locally developed and validated locomotor disability measurement scale in Bangladesh. The purpose of this study was to develop a locomotor disability scale with disability indicators suitable for adults in Bangladesh. Semi-structured interviews were conducted with 25 purposively selected adults with locomotor disabilities to generate scale items. At the second stage, cognitive interviews were conducted with 12 purposively selected adults with locomotor disabilities in order to refine the measurement questions and response categories. Data were analysed using the framework technique- identifying, abstracting, charting and matching themes across the interviews. For a locomotor disability scale, 70 activities (disability indicators) were identified: 37 mobility activities, 9 activities of daily living, 17 work/productivity activities and 7 leisure activities. Cognitive interviews revealed that when asking the respondents to rate their difficulty in performing the activities, instead of just mentioning the activity name, such as taking a bath or shower, a detailed description of the activity and response options were necessary to ensure consistent interpretation of the disability indicators and response options across all respondents. Identifying suitable disability indicators was the first step in developing a locomotor disability scale for adults in Bangladesh. Interviewing adults with locomotor disabilities in Bangladesh ensured that the locomotor disability scale is of relevance to them and consequently it has excellent content validity. Further research is needed to evaluate the psychometric properties of this scale.

Effects of cholestasis on learning and locomotor activity in bile duct ligated rats.

Science.gov (United States)

Hosseini, Nasrin; Alaei, Hojjatallah; Nasehi, Mohammad; Radahmadi, Maryam; Mohammad Reza, Zarrindast

2014-01-01

Cognitive functions are impaired in patients with liver disease. Bile duct ligation causes cholestasis that impairs liver function. This study investigated the impact of cholestasis progression on the acquisition and retention times in the passive avoidance test and on the locomotor activity of rats. Cholestasis was induced in male Wistar rats by ligating the main bile duct. Locomotor activity, learning and memory were assessed by the passive avoidance learning test at day 7, day 14, and day 21 post-bile duct ligation. The serum levels of bilirubin, alanine aminotransferase, and alkaline phosphatase were measured. The results showed that acquisition time and locomotor activity were not affected at day 7 and day 14, but they were significantly (P locomotor activity were impaired at 21 days after bile duct ligation following the progression of cholestasis.

Gossiping Capabilities

DEFF Research Database (Denmark)

Mogensen, Martin; Frey, Davide; Guerraoui, Rachid

Gossip-based protocols are now acknowledged as a sound basis to implement collaborative high-bandwidth content dissemination: content location is disseminated through gossip, the actual contents being subsequently pulled. In this paper, we present HEAP, HEterogeneity Aware gossip Protocol, where...... nodes dynamically adjust their contribution to gossip dissemination according to their capabilities. Using a continuous, itself gossip-based, approximation of relative capabilities, HEAP dynamically leverages the most capable nodes by (a) increasing their fanouts (while decreasing by the same proportion...... declare a high capability in order to augment their perceived quality without contributing accordingly. We evaluate HEAP in the context of a video streaming application on a 236 PlanetLab nodes testbed. Our results shows that HEAP improves the quality of the streaming by 25% over a standard gossip...

Start-up’s Performance: An Empirical Study on Dynamic Capabilities Under The Contributions of Bricolage and Social Capital

OpenAIRE

Huynh, Thanh; Patton, Dean

2016-01-01

Objectives: Dynamic capabilities studies have emphasised how firms determine, integrate, build and reconfigure internal and external resources to adapt to rapidly changing business environment (Teece et al., 1997). Dynamic capabilities are described as routines to learn routines, resource integration consists of product development routines and strategic decision making, resource reconfiguration, and resource gain and release which include knowledge creation, alliance and acquisition routines...

Woodlouse locomotor behavior in the assessment of clean and contaminated field sites

Energy Technology Data Exchange (ETDEWEB)

Bayley, M.; Baatrup, E. [Aarhus Univ. (Denmark). Inst. of Biological Sciences; Bjerregaard, P. [Odense Univ. (Denmark). Inst. of Biology

1997-11-01

Specimens of the woodlouse Oniscus asellus were collected at four clean field sites and from a recently closed iron foundry heavily contaminated with zinc, lead, chromium, and nickel. Each of the 30 woodlice per group was housed individually and acclimatized to laboratory conditions for 2 d on a humid plaster of paris substrate. Thereafter, the locomotor behavior of each animal was measured for 4 h employing automated computer-aided video tracking. Linear discriminant analysis of five locomotor parameters revealed average velocity and path length as the principle components separating the polluted site and control animals. Post hoc analysis of the discriminant variable for animals from all five sites showed that the animals from the polluted site where significantly hyperactive when compared to all controls. Further, control animals collected from sites separated by several hundred kilometers were remarkably similar in their locomotor behavior. This preliminary study highlights the potential utility of quantitative analysis of animal locomotor behavior in environmental monitoring.

Dynamic behavioral fingerprinting': What drives the deployment of environmental information and communication capabilities?

NARCIS (Netherlands)

Bremmers, H.J.; Haverkamp, D.J.; Omta, S.W.F.

2009-01-01

This article investigates the impact of organizational drivers for the implementation of business process and network information and communication capabilities (ICCs) supporting cleaner production in the Dutch food and beverage industry. We do so with the intention to promote `dynamic behavioral

Dynamic managerial capability of technology-based international new ventures

DEFF Research Database (Denmark)

Altshuler, Liliya

2014-01-01

case study of a technology-based INV conducted over the period of 3.5 years, starting 8 years into the firm’s history. This unique design has enabled close observation of the specific events and challenges the firm has been facing after its initial success, and of the aspects in the firm’s management...... to resource availability. The study takes the dynamic capability perspective and focuses on INVs’ management, which are seen as founders and builders of the processes, rules and structures that lay the basis for long-term competitive advantage for such firms. Based on the findings, specific aspects...

A wider pelvis does not increase locomotor cost in humans, with implications for the evolution of childbirth.

Directory of Open Access Journals (Sweden)

Anna G Warrener

Full Text Available The shape of the human female pelvis is thought to reflect an evolutionary trade-off between two competing demands: a pelvis wide enough to permit the birth of large-brained infants, and narrow enough for efficient bipedal locomotion. This trade-off, known as the obstetrical dilemma, is invoked to explain the relative difficulty of human childbirth and differences in locomotor performance between men and women. The basis for the obstetrical dilemma is a standard static biomechanical model that predicts wider pelves in females increase the metabolic cost of locomotion by decreasing the effective mechanical advantage of the hip abductor muscles for pelvic stabilization during the single-leg support phase of walking and running, requiring these muscles to produce more force. Here we experimentally test this model against a more accurate dynamic model of hip abductor mechanics in men and women. The results show that pelvic width does not predict hip abductor mechanics or locomotor cost in either women or men, and that women and men are equally efficient at both walking and running. Since a wider birth canal does not increase a woman's locomotor cost, and because selection for successful birthing must be strong, other factors affecting maternal pelvic and fetal size should be investigated in order to help explain the prevalence of birth complications caused by a neonate too large to fit through the birth canal.

Engagement of the Rat Hindlimb Motor Cortex across Natural Locomotor Behaviors.

Science.gov (United States)

DiGiovanna, Jack; Dominici, Nadia; Friedli, Lucia; Rigosa, Jacopo; Duis, Simone; Kreider, Julie; Beauparlant, Janine; van den Brand, Rubia; Schieppati, Marco; Micera, Silvestro; Courtine, Grégoire

2016-10-05

Contrary to cats and primates, cortical contribution to hindlimb locomotor movements is not critical in rats. However, the importance of the motor cortex to regain locomotion after neurological disorders in rats suggests that cortical engagement in hindlimb motor control may depend on the behavioral context. To investigate this possibility, we recorded whole-body kinematics, muscle synergies, and hindlimb motor cortex modulation in freely moving rats performing a range of natural locomotor procedures. We found that the activation of hindlimb motor cortex preceded gait initiation. During overground locomotion, the motor cortex exhibited consistent neuronal population responses that were synchronized with the spatiotemporal activation of hindlimb motoneurons. Behaviors requiring enhanced muscle activity or skilled paw placement correlated with substantial adjustment in neuronal population responses. In contrast, all rats exhibited a reduction of cortical activity during more automated behavior, such as stepping on a treadmill. Despite the facultative role of the motor cortex in the production of locomotion in rats, these results show that the encoding of hindlimb features in motor cortex dynamics is comparable in rats and cats. However, the extent of motor cortex modulations appears linked to the degree of volitional engagement and complexity of the task, reemphasizing the importance of goal-directed behaviors for motor control studies, rehabilitation, and neuroprosthetics. We mapped the neuronal population responses in the hindlimb motor cortex to hindlimb kinematics and hindlimb muscle synergies across a spectrum of natural locomotion behaviors. Robust task-specific neuronal population responses revealed that the rat motor cortex displays similar modulation as other mammals during locomotion. However, the reduced motor cortex activity during more automated behaviors suggests a relationship between the degree of engagement and task complexity. This relationship

Capabilities for innovation

DEFF Research Database (Denmark)

Nielsen, Peter; Nielsen, Rene Nesgaard; Bamberger, Simon Grandjean

2012-01-01

is a survey that collected information from 601 firms belonging to the private urban sector in Denmark. The survey was carried out in late 2010. Keywords: dynamic capabilities/innovation/globalization/employee/employer cooperation/Nordic model Acknowledgment: The GOPA study was financed by grant 20080053113......Technological developments combined with increasing levels of competition related to the ongoing globalization imply that firms find themselves in dynamic, changing environments that call for dynamic capabilities. This challenges the internal human and organizational resources of firms in general...

Using a Split-belt Treadmill to Evaluate Generalization of Human Locomotor Adaptation.

Science.gov (United States)

Vasudevan, Erin V L; Hamzey, Rami J; Kirk, Eileen M

2017-08-23

Understanding the mechanisms underlying locomotor learning helps researchers and clinicians optimize gait retraining as part of motor rehabilitation. However, studying human locomotor learning can be challenging. During infancy and childhood, the neuromuscular system is quite immature, and it is unlikely that locomotor learning during early stages of development is governed by the same mechanisms as in adulthood. By the time humans reach maturity, they are so proficient at walking that it is difficult to come up with a sufficiently novel task to study de novo locomotor learning. The split-belt treadmill, which has two belts that can drive each leg at a different speed, enables the study of both short- (i.e., immediate) and long-term (i.e., over minutes-days; a form of motor learning) gait modifications in response to a novel change in the walking environment. Individuals can easily be screened for previous exposure to the split-belt treadmill, thus ensuring that all experimental participants have no (or equivalent) prior experience. This paper describes a typical split-belt treadmill adaptation protocol that incorporates testing methods to quantify locomotor learning and generalization of this learning to other walking contexts. A discussion of important considerations for designing split-belt treadmill experiments follows, including factors like treadmill belt speeds, rest breaks, and distractors. Additionally, potential but understudied confounding variables (e.g., arm movements, prior experience) are considered in the discussion.

The Effects of Sex-Ratio and Density on Locomotor Activity in the House Fly, Musca domestica

Science.gov (United States)

Bahrndorff, Simon; Kjærsgaard, Anders; Pertoldi, Cino; Loeschcke, Volker; Schou, Toke M.; Skovgård, Henrik; Hald, Birthe

2012-01-01

Although locomotor activity is involved in almost all behavioral traits, there is a lack of knowledge on what factors affect it. This study examined the effects of sex—ratio and density on the circadian rhythm of locomotor activity of adult Musca domestica L. (Diptera: Muscidae) using an infra—red light system. Sex—ratio significantly affected locomotor activity, increasing with the percentage of males in the vials. In accordance with other studies, males were more active than females, but the circadian rhythm of the two sexes was not constant over time and changed during the light period. There was also an effect of density on locomotor activity, where males at intermediate densities showed higher activity. Further, the predictability of the locomotor activity, estimated as the degree of autocorrelation of the activity data, increased with the number of males present in the vials both with and without the presence of females. Overall, this study demonstrates that locomotor activity in M. domestica is affected by sex—ratio and density. Furthermore, the predictability of locomotor activity is affected by both sex—ratio, density, and circadian rhythm. These results add to our understanding of the behavioral interactions between houseflies and highlight the importance of these factors when designing behavioral experiments using M. domestica.

Cross-Sector Partnerships and the Co-creation of Dynamic Capabilities for Stakeholder Orientation

NARCIS (Netherlands)

Dentoni, D.; Bitzer, V.C.; Pascucci, S.

2016-01-01

This paper explores the relationship between business experience in cross-sector partnerships (CSPs) and the co-creation of what we refer to as ‘dynamic capabilities for stakeholder orientation,’ consisting of the four dimensions of (1) sensing, (2) interacting with, (3) learning from and (4)

Ankle voluntary movement enhancement following robotic-assisted locomotor training in spinal cord injury.

Science.gov (United States)

Varoqui, Deborah; Niu, Xun; Mirbagheri, Mehdi M

2014-03-31

In incomplete spinal cord injury (iSCI), sensorimotor impairments result in severe limitations to ambulation. To improve walking capacity, physical therapies using robotic-assisted locomotor devices, such as the Lokomat, have been developed. Following locomotor training, an improvement in gait capabilities-characterized by increases in the over-ground walking speed and endurance-is generally observed in patients. To better understand the mechanisms underlying these improvements, we studied the effects of Lokomat training on impaired ankle voluntary movement, known to be an important limiting factor in gait for iSCI patients. Fifteen chronic iSCI subjects performed twelve 1-hour sessions of Lokomat training over the course of a month. The voluntary movement was qualified by measuring active range of motion, maximal velocity peak and trajectory smoothness for the spastic ankle during a movement from full plantar-flexion (PF) to full dorsi-flexion (DF) at the patient's maximum speed. Dorsi- and plantar-flexor muscle strength was quantified by isometric maximal voluntary contraction (MVC). Clinical assessments were also performed using the Timed Up and Go (TUG), the 10-meter walk (10MWT) and the 6-minute walk (6MWT) tests. All evaluations were performed both before and after the training and were compared to a control group of fifteen iSCI patients. After the Lokomat training, the active range of motion, the maximal velocity, and the movement smoothness were significantly improved in the voluntary movement. Patients also exhibited an improvement in the MVC for their ankle dorsi- and plantar-flexor muscles. In terms of functional activity, we observed an enhancement in the mobility (TUG) and the over-ground gait velocity (10MWT) with training. Correlation tests indicated a significant relationship between ankle voluntary movement performance and the walking clinical assessments. The improvements of the kinematic and kinetic parameters of the ankle voluntary movement

Determinants of locomotor disability in people aged 55 years and over: The Rotterdam study

International Nuclear Information System (INIS)

Odding, Else; Valkenburg, Hans A.; Stam, Hendrik J.; Hofman, Albert

2001-01-01

Locomotor disability, as defined by difficulties in activities of daily living related to lower limb function, can be the consequence of diseases and impairments of the cardiovascular, pulmonary, nervous, sensory and musculoskeletal system. We estimated the associations between specific diseases and impairments and locomotor disability, and the proportion of disability attributable to each condition, controlling for age and comorbidity. The Rotterdam Study is a prospective follow-up study among people aged 55 years and over in the general population. Locomotor disability in 1219 men and 1856 women was assessed with the Stanford Health Assessment Questionnaire. Diseases and impairments were radiological osteoarthritis, pain of the hips and knees, morning stiffness, fractures, hypertension, vascular disease, ischemic heart disease, stroke, heart failure, chronic obstructive pulmonary disease (COPD), depression, Parkinson's disease, osteoporosis, diabetes mellitus, overweight, and low vision. Adjusted odds ratios, etiologic and attributable fractions were calculated for locomotor disability. The occurrence of locomotor disability can partly be ascribed to joint pain, COPD, morning stiffness, diabetes and heart failure in both men and women. In addition in women osteoarthritis, osteoporosis, low vision, fractures, stroke and Parkinson's disease are significant etiologic fractions. In men with morning stiffness, joint pain, heart failure, diabetes mellitus, and COPD a significant proportion of their disability is attributable to this impairment. In women this was the case for Parkinson's disease, morning stiffness, low vision, heart failure, joint pain, diabetes, radiological osteoarthritis, stroke, COPD, osteoporosis, and fractures of the lower limbs, in that order. We conclude that locomotor complaints, heart failure, COPD and diabetes mellitus contribute considerably to locomotor disability in non-institutionalized elderly people

Vestibular lesion-induced developmental plasticity in spinal locomotor networks during Xenopus laevis metamorphosis.

Science.gov (United States)

Beyeler, Anna; Rao, Guillaume; Ladepeche, Laurent; Jacques, André; Simmers, John; Le Ray, Didier

2013-01-01

During frog metamorphosis, the vestibular sensory system remains unchanged, while spinal motor networks undergo a massive restructuring associated with the transition from the larval to adult biomechanical system. We investigated in Xenopus laevis the impact of a pre- (tadpole stage) or post-metamorphosis (juvenile stage) unilateral labyrinthectomy (UL) on young adult swimming performance and underlying spinal locomotor circuitry. The acute disruptive effects on locomotion were similar in both tadpoles and juvenile frogs. However, animals that had metamorphosed with a preceding UL expressed restored swimming behavior at the juvenile stage, whereas animals lesioned after metamorphosis never recovered. Whilst kinematic and electrophysiological analyses of the propulsive system showed no significant differences in either juvenile group, a 3D biomechanical simulation suggested that an asymmetry in the dynamic control of posture during swimming could account for the behavioral restoration observed in animals that had been labyrinthectomized before metamorphosis. This hypothesis was subsequently supported by in vivo electromyography during free swimming and in vitro recordings from isolated brainstem/spinal cord preparations. Specifically, animals lesioned prior to metamorphosis at the larval stage exhibited an asymmetrical propulsion/posture coupling as a post-metamorphic young adult. This developmental alteration was accompanied by an ipsilesional decrease in propriospinal coordination that is normally established in strict left-right symmetry during metamorphosis in order to synchronize dorsal trunk muscle contractions with bilateral hindlimb extensions in the swimming adult. Our data thus suggest that a disequilibrium in descending vestibulospinal information during Xenopus metamorphosis leads to an altered assembly of adult spinal locomotor circuitry. This in turn enables an adaptive compensation for the dynamic postural asymmetry induced by the vestibular imbalance

Locomotor activity: A distinctive index in morphine self-administration in rats

OpenAIRE

Zhang, Jian-Jun; Kong, Qingyao

2017-01-01

Self-administration of addictive drugs is a widely used tool for studying behavioral, neurobiological, and genetic factors in addiction. However, how locomotor activity is affected during self-administration of addictive drugs has not been extensively studied. In our present study, we tested the locomotor activity levels during acquisition, extinction and reinstatement of morphine self-administration in rats. We found that compared with saline self-administration (SA), rats that trained with ...

Cell phone-generated radio frequency electromagnetic field effects on the locomotor behaviors of the fishes Poecilia reticulata and Danio rerio.

Science.gov (United States)

Lee, David; Lee, Joshua; Lee, Imshik

2015-01-01

The locomotor behavior of small fish was characterized under a cell phone-generated radio frequency electromagnetic field (RF EMF). The trajectory of movement of 10 pairs of guppy (Poecilia reticulate) and 15 pairs of Zebrafish (Danio rerio) in a fish tank was recorded and tracked under the presence of a cell phone-generated RF EMF. The measures were based on spatial and temporal distributions. A time-series trajectory was utilized to emphasize the dynamic nature of locomotor behavior. Fish movement was recorded in real-time. Their spatial, velocity, turning angle and sinuosity distribution were analyzed in terms of F(v,x), P[n(x,t)], P(v), F (θ) and F(s), respectively. In addition, potential temperature elevation caused by a cellular phone was also examined. We demonstrated that a cellular phone-induced temperature elevation was not relevant, and that our measurements reflected RF EMF-induced effects on the locomotor behavior of Poecilia reticulata and Danio rerio. Fish locomotion was observed under normal conditions, in the visual presence of a cell phone, after feeding, and under starvation. Fish locomotor behavior was random both in normal conditions and in the presence of an off-signaled cell phone. However, there were significant changes in the locomotion of the fish after feeding under the RF EMF. The locomotion of the fed fish was affected in terms of changes in population and velocity distributions under the presence of the RF EMF emitted by the cell phone. There was, however, no significant difference in angular distribution.

Effect of thiamethoxam on cockroach locomotor activity is associated with its metabolite clothianidin.

Science.gov (United States)

Benzidane, Yassine; Touinsi, Sarra; Motte, Emilie; Jadas-Hécart, Alain; Communal, Pierre-Yves; Leduc, Lionel; Thany, Steeve H

2010-12-01

In the present study, the effect of thiamethoxam and clothianidin on the locomotor activity of American cockroach, Periplaneta americana (L.), was evaluated. Because it has been proposed that thiamethoxam is metabolised to clothianidin, high-performance liquid chromatography coupled with mass spectrometry was used to evaluate the amount of clothianidin on thiamethoxam-treated cockroaches. One hour after neonicotinoid treatment, the time spent in the open-field-like apparatus significantly increased, suggesting a decrease in locomotor activity. The percentage of cockroaches displaying locomotor activity was significantly reduced 1 h after haemolymph application of 1 nmol g(-1) neonicotinoid, while no significant effect was found after topical and oral administration. However, at 24 and 48 h, all neonicotinoids were able to reduce locomotor activity, depending on their concentrations and the way they were applied. Interestingly, it was found that thiamethoxam was converted to clothianidin 1 h after application, but the amount of clothianidin did not rise proportionately to thiamethoxam, especially after oral administration. The data suggest that the effect of thiamethoxam on cockroach locomotor activity is due in part to clothianidin action because (1) thiamethoxam levels remained persistent 48 h after application and (2) the amount of clothianidin in cockroach tissues was consistent with the toxicity of thiamethoxam. Copyright © 2010 Society of Chemical Industry.

Locomotor Tests Predict Community Mobility in Children and Youth with Cerebral Palsy

Science.gov (United States)

Ferland, Chantale; Moffet, Helene; Maltais, Desiree

2012-01-01

Ambulatory children and youth with cerebral palsy have limitations in locomotor capacities and in community mobility. The ability of three locomotor tests to predict community mobility in this population (N = 49, 27 boys, 6-16 years old) was examined. The tests were a level ground walking test, the 6-min-Walk-Test (6MWT), and two tests of advanced…

Nuclear Hybrid Energy System Modeling: RELAP5 Dynamic Coupling Capabilities

Energy Technology Data Exchange (ETDEWEB)

Piyush Sabharwall; Nolan Anderson; Haihua Zhao; Shannon Bragg-Sitton; George Mesina

2012-09-01

The nuclear hybrid energy systems (NHES) research team is currently developing a dynamic simulation of an integrated hybrid energy system. A detailed simulation of proposed NHES architectures will allow initial computational demonstration of a tightly coupled NHES to identify key reactor subsystem requirements, identify candidate reactor technologies for a hybrid system, and identify key challenges to operation of the coupled system. This work will provide a baseline for later coupling of design-specific reactor models through industry collaboration. The modeling capability addressed in this report focuses on the reactor subsystem simulation.

Neuropharmacology of light-induced locomotor activation.

Science.gov (United States)

Amato, Davide; Pum, Martin E; Groos, Dominik; Lauber, Andrea C; Huston, Joseph P; Carey, Robert J; de Souza Silva, Maria A; Müller, Christian P

2015-08-01

Presentation of non-aversive light stimuli for several seconds was found to reliably induce locomotor activation and exploratory-like activity. Light-induced locomotor activity (LIA) can be considered a convenient simple model to study sensory-motor activation. LIA was previously shown to coincide with serotonergic and dopaminergic activation in specific cortical areas in freely moving and anesthetized animals. In the present study we explore the neuropharmacology of LIA using a receptor antagonist/agonist approach in rats. The non-selective 5-HT2-receptor antagonist ritanserin (1.5-6 mg/kg, i.p.) dose-dependently reduced LIA. Selective antagonism of either the 5-HT2A-receptor by MDL 11,939 (0.1-0.4 mg/kg, i.p.), or the 5-HT2C-receptor by SDZ SER 082 (0.125-0.5 mg/kg, i.p.), alone or in combination, had no significant influence on LIA. Also the selective 5-HT1A-receptor antagonist, WAY 100635 (0.4 mg/kg, i.p.) did not affect LIA. Neither did the preferential dopamine D2-receptor antagonist, haloperidol (0.025-0.1 mg/kg, i.p.) nor the D2/D3-receptor agonist, quinpirole (0.025-0.5 mg/kg, i.p.) affect the expression of LIA. However, blocking the glutamatergic NMDA-receptor with phencyclidine (PCP, 1.5-6 mg/kg, i.p.) dose-dependently reduced LIA. This effect was also observed with ketamine (10 mg/kg, i.p.). These findings suggest that serotonin and dopamine receptors abundantly expressed in the cortex do not mediate light-stimulus triggered locomotor activity. PCP and ketamine effects, however, suggest an important role of NMDA receptors in LIA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Engagement of the Rat Hindlimb Motor Cortex across Natural Locomotor Behaviors

OpenAIRE

DiGiovanna, J.; Dominici, N.; Friedli, L.; Rigosa, J.; Duis, S.; Kreider, J.; Beauparlant, J.; van den Brand, R.; Schieppati, M.; Micera, S.; Courtine, G.

2016-01-01

Contrary to cats and primates, cortical contribution to hindlimb locomotor movements is not critical in rats. However, the importance of the motor cortex to regain locomotion after neurological disorders in rats suggests that cortical engagement in hindlimb motor control may depend on the behavioral context. To investigate this possibility, we recorded whole-body kinematics, muscle synergies, and hindlimb motor cortex modulation in freely moving rats performing a range of natural locomotor pr...

Inward Internationalization of African-Ethnic Restaurants: The Role of Managerial Dynamic Capabilities

Directory of Open Access Journals (Sweden)

Samson Omuudu OTENGEI

2016-12-01

Full Text Available This paper empirically tests the link between cultural orientation, market orientation, service innovation capabilities of owner-managers and the level of inward internationalisation of African-ethnic restaurants. Data were obtained from 201 African-ethnic restaurants. A twostep approach was used, i.e. (i a confirmatory factor analysis (CFA to generate a measurement model; and (ii a structural equation model (SEM to test the hypotheses. All the predictor variables are positively and significantly related to the degree of inward internationalisation and the relationship is strong enough to cause a 41 per cent variance. Since it is cross-sectional in design, the study cannot be fully relied upon to draw inferences regarding causality among the variables. The results suggest that owner-managers who develop the three capabilities succeed in enhancing inward internationalisation. The current study could be among the very few to propose a framework that brings together major managerial (dynamic capabilities that are presumed to be vital in enhancing inward internationalisation.

Locomotor Muscle Fatigue Does Not Alter Oxygen Uptake Kinetics during High-Intensity Exercise.

Science.gov (United States)

Hopker, James G; Caporaso, Giuseppe; Azzalin, Andrea; Carpenter, Roger; Marcora, Samuele M

2016-01-01

The [Formula: see text] slow component ([Formula: see text]) that develops during high-intensity aerobic exercise is thought to be strongly associated with locomotor muscle fatigue. We sought to experimentally test this hypothesis by pre-fatiguing the locomotor muscles used during subsequent high-intensity cycling exercise. Over two separate visits, eight healthy male participants were asked to either perform a non-metabolically stressful 100 intermittent drop-jumps protocol (pre-fatigue condition) or rest for 33 min (control condition) according to a random and counterbalanced order. Locomotor muscle fatigue was quantified with 6-s maximal sprints at a fixed pedaling cadence of 90 rev·min -1 . Oxygen kinetics and other responses (heart rate, capillary blood lactate concentration and rating of perceived exertion, RPE) were measured during two subsequent bouts of 6 min cycling exercise at 50% of the delta between the lactate threshold and [Formula: see text] determined during a preliminary incremental exercise test. All tests were performed on the same cycle ergometer. Despite significant locomotor muscle fatigue ( P = 0.03), the [Formula: see text] was not significantly different between the pre-fatigue (464 ± 301 mL·min -1 ) and the control (556 ± 223 mL·min -1 ) condition ( P = 0.50). Blood lactate response was not significantly different between conditions ( P = 0.48) but RPE was significantly higher following the pre-fatiguing exercise protocol compared with the control condition ( P locomotor muscle fatigue does not significantly alter the [Formula: see text] kinetic response to high intensity aerobic exercise, and challenge the hypothesis that the [Formula: see text] is strongly associated with locomotor muscle fatigue.

Potential contributions of training intensity on locomotor performance in individuals with chronic stroke.

Science.gov (United States)

Holleran, Carey L; Rodriguez, Kelly S; Echauz, Anthony; Leech, Kristan A; Hornby, T George

2015-04-01

Many interventions can improve walking ability of individuals with stroke, although the training parameters that maximize recovery are not clear. For example, the contribution of training intensity has not been well established and may contribute to the efficacy of many locomotor interventions. The purpose of this preliminary study was to evaluate the effects of locomotor training intensity on walking outcomes in individuals with gait deficits poststroke. Using a randomized cross-over design, 12 participants with chronic stroke (>6-month duration) performed either high-intensity (70%-80% of heart rate reserve; n = 6) or low-intensity (30%-40% heart rate reserve; n = 6) locomotor training for 12 or fewer sessions over 4 to 5 weeks. Four weeks following completion, the alternate training intervention was performed. Training intensity was manipulated by adding loads or applying resistance during walking, with similar speeds, durations, and amount of stepping practice between conditions. Greater increases in 6-Minute Walk Test performance were observed following high-intensity training compared with low-intensity training. A significant interaction of intensity and order was also observed for 6-Minute Walk Test and peak treadmill speed, with the largest changes in those who performed high-intensity training first. Moderate correlations were observed between locomotor outcomes and measures of training intensity. This study provides the first evidence that the intensity of locomotor practice may be an important independent determinant of walking outcomes poststroke. In the clinical setting, the intensity of locomotor training can be manipulated in many ways, although this represents only 1 parameter to consider.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A90).

Locomotor muscle fatigue does not alter oxygen uptake kinetics during high-intensity exercise

Directory of Open Access Journals (Sweden)

James Hopker

2016-10-01

Full Text Available The slow component (VO2sc that develops during high-intensity aerobic exercise is thought to be strongly associated with locomotor muscle fatigue. We sought to experimentally test this hypothesis by pre-fatiguing the locomotor muscles used during subsequent high-intensity cycling exercise. Over two separate visits, eight healthy male participants were asked to either perform a non-metabolically stressful 100 intermittent drop-jumps protocol (pre fatigue condition or rest for 33 minutes (control condition according to a random and counterbalanced order. Locomotor muscle fatigue was quantified with 6-second maximal sprints at a fixed pedaling cadence of 90 rev·min-1. Oxygen kinetics and other responses (heart rate, capillary blood lactate concentration and rating of perceived exertion, RPE were measured during two subsequent bouts of 6 min cycling exercise at 50% of the delta between the lactate threshold and VO2max determined during a preliminary incremental exercise test. All tests were performed on the same cycle ergometer. Despite significant locomotor muscle fatigue (P = 0.03, the VO2sc was not significantly different between the pre fatigue (464 ± 301 mL·min-1 and the control (556 ± 223 mL·min-1 condition (P = 0.50. Blood lactate response was not significantly different between conditions (P = 0.48 but RPE was significantly higher following the pre-fatiguing exercise protocol compared with the control condition (P < 0.01 suggesting higher muscle recruitment. These results demonstrate experimentally that locomotor muscle fatigue does not significantly alter the VO2 kinetic response to high intensity aerobic exercise, and challenge the hypothesis that the VO2sc is strongly associated with locomotor muscle fatigue.

Global dynamics, capabilities and the crisis

Czech Academy of Sciences Publication Activity Database

Fagerberg, J.; Srholec, Martin

2016-01-01

Roč. 26, č. 4 (2016), s. 765-784 ISSN 0936-9937 Institutional support: PRVOUK-P23 Keywords : technological capabilities * social capabilities * competitiveness Subject RIV: AH - Economics Impact factor: 0.862, year: 2016

The Role Of Dynamic Capability In Supporting Transformation And Sustainability Of Permodalan Nasional Madani Ltd

Directory of Open Access Journals (Sweden)

Harry Sutanto

2015-08-01

Full Text Available This research is motivated by the empirical facts that although the Micro Small Medium Enterprises and despite getting optimal support the Indonesian government in recognition of the significance of its role in supporting the nations economy has experienced stagnation of business growth reflected by lower vertical mobility in the form of small industrial upgrading into secondary industries than medium industrial decline into a small industry. Permodalan Nasional Madani Lt.d the company with a status and legal domicile as a financial state owned enterprise to support Micro Small Medium Enterprises through financing as a financial solution and coaching as a solution of non-financial to form a strong independent and be able to create new jobs.In the period 2009-2013 the company has implemented Transformation First in response to the dynamic changes facing as well as an increase in competence fluctuations in economic conditions and other related matters that put the company in a sharp business complexity. The success of the company carrying out the First Transformation 2009-2013 both in a significant improvement and performance management of the company became the starting point in the implementation of the Second Transformation 2014-2019 and further measures to achieve organization sustainability.The phenomenon of the companys success in implementing the 2009-2013 First Transformation considered highly supported by the formulation and implementation of dynamic capability approach strategy so as to change the paradigm of management of the company from its original direction as financial state owned enterprise with the full support of the government into business-oriented institution to the achievement of sustainable advantage sustainable profit and supported by governance governance good company. This research is in the areas of change management and strategic management more specifically on the development of the concept of dynamic capabilities in

Feedback and feedforward locomotor adaptations to ankle-foot load in people with incomplete spinal cord injury.

Science.gov (United States)

Gordon, Keith E; Wu, Ming; Kahn, Jennifer H; Schmit, Brian D

2010-09-01

Humans with spinal cord injury (SCI) modulate locomotor output in response to limb load. Understanding the neural control mechanisms responsible for locomotor adaptation could provide a framework for selecting effective interventions. We quantified feedback and feedforward locomotor adaptations to limb load modulations in people with incomplete SCI. While subjects airstepped (stepping performed with kinematic assistance and 100% bodyweight support), a powered-orthosis created a dorisflexor torque during the "stance phase" of select steps producing highly controlled ankle-load perturbations. When given repetitive, stance phase ankle-load, the increase in hip extension work, 0.27 J/kg above baseline (no ankle-load airstepping), was greater than the response to ankle-load applied during a single step, 0.14 J/kg (P = 0.029). This finding suggests that, at the hip, subjects produced both feedforward and feedback locomotor modulations. We estimate that, at the hip, the locomotor response to repetitive ankle-load was modulated almost equally by ongoing feedback and feedforward adaptations. The majority of subjects also showed after-effects in hip kinetic patterns that lasted 3 min in response to repetitive loading, providing additional evidence of feedforward locomotor adaptations. The magnitude of the after-effect was proportional to the response to repetitive ankle-foot load (R(2) = 0.92). In contrast, increases in soleus EMG amplitude were not different during repetitive and single-step ankle-load exposure, suggesting that ankle locomotor modulations were predominately feedback-based. Although subjects made both feedback and feedforward locomotor adaptations to changes in ankle-load, between-subject variations suggest that walking function may be related to the ability to make feedforward adaptations.

V1 spinal neurons regulate the speed of vertebrate locomotor outputs

DEFF Research Database (Denmark)

Gosgnach, Simon; Lanuza, Guillermo M.; Butt, Simon J B

2006-01-01

The neuronal networks that generate vertebrate movements such as walking and swimming are embedded in the spinal cord1-3. These networks, which are referred to as central pattern generators (CPGs), are ideal systems for determining how ensembles of neurons generate simple behavioural outputs...... for inhibition in regulating the frequency of the locomotor CPG rhythm, and also suggest that V1 neurons may have an evolutionarily conserved role in controlling the speed of vertebrate locomotor movements....

Oxidized trilinoleate and tridocosahexaenoate induce pica behavior and change locomotor activity.

Science.gov (United States)

Kitamura, Fuki; Watanabe, Hiroyuki; Umeno, Aya; Yoshida, Yasukazu; Kurata, Kenji; Gotoh, Naohiro

2013-01-01

Pica behavior, a behavior that is characterized by eating a nonfood material such as kaolin and relates to the degree of discomfort in animals, and the variations of locomotor activity of rats after eating deteriorated fat and oil extracted from instant noodles were examined in our previous study. The result shows that oxidized fat and oil with at least 100 meq/kg in peroxide value (PV) increase pica behavior and decrease locomotor activity. In the present study, the same two behaviors were measured using autoxidized trilinoleate (tri-LA) and tridocosahexaenoate (tri-DHA) as a model of vegetable and fish oil, respectively, to compare fatty acid differences against the induction of two behaviors. The oxidized levels of tri-LA and tri-DHA were analyzed with PV and p-anisidine value (AnV), the method to analyze secondary oxidized products. The oxidation levels of respective triacylglycerol (TAG) samples were carefully adjusted to make them having almost the same PV and AnV. As the results, 600 or more meq/kg in PV of both TAGs significantly increased the consumption of kaolin pellets compared to the control group. Furthermore, 300 or more meq/kg in PV of tri-LA and 200 or more meq/kg in PV of tri-DHA demonstrated significant decrease in locomotor activity compared to control group. These results would indicate that the oxidized TAG having the same PV and/or AnV would induce the same type of pica behavior and locomotor activity. Furthermore, that the structure of oxidized products might not be important and the amount of hydroperoxide group and/or aldehyde group in deteriorated fats and oils might affect the pica behavior and locomotor activity were thought.

The effects of long-term dopaminergic treatment on locomotor behavior in rats.

Science.gov (United States)

Oliveira de Almeida, Welinton Alessandro; Maculano Esteves, Andrea; Leite de Almeida-Júnior, Canuto; Lee, Kil Sun; Kannebley Frank, Miriam; Oliveira Mariano, Melise; Frussa-Filho, Roberto; Tufik, Sergio; Tulio de Mello, Marco

2014-12-01

Long-term treatments with dopaminergic agents are associated with adverse effects, including augmentation. Augmentation consists of an exacerbation of restless legs syndrome (a sleep-related movement disorder) symptoms during treatment compared to those experienced during the period before therapy was initiated. The objective of this study was to examine locomotor activity in rats after long-term dopaminergic treatment and its relationship with expression of the D2 receptor, in addition to demonstrating possible evidence of augmentation. The rats were divided into control (CTRL) and drug (Pramipexole-PPX) groups that received daily saline vehicle and PPX treatments, respectively, for 71 days. The locomotor behavior of the animals was evaluated weekly in the Open Field test for 71 days. The expression of the dopamine D2 receptor was evaluated by Western Blot analysis. The animals that received the PPX demonstrated a significant reduction in locomotor activity from day 1 to day 57 and a significant increase in immobility time from day 1 to day 64 relative to baseline values, but these values had returned to baseline levels at 71 days. No changes in the expression of the D2 receptor were demonstrated after treatment with a dopaminergic agonist. This study suggests changes in locomotor activity in rats after long-term PPX treatment that include an immediate reduction of locomotion and an increase in immobilization, and after 64 days, these values returned to baseline levels without evidence of augmentation. In addition, it was not possible to demonstrate a relationship between locomotor activity and the expression of D2 receptors under these conditions.

The effects of long-term dopaminergic treatment on locomotor behavior in rats

Science.gov (United States)

Oliveira de Almeida, Welinton Alessandro; Maculano Esteves, Andrea; Leite de Almeida-Júnior, Canuto; Lee, Kil Sun; Kannebley Frank, Miriam; Oliveira Mariano, Melise; Frussa-Filho, Roberto; Tufik, Sergio; Tulio de Mello, Marco

2014-01-01

Long-term treatments with dopaminergic agents are associated with adverse effects, including augmentation. Augmentation consists of an exacerbation of restless legs syndrome (a sleep-related movement disorder) symptoms during treatment compared to those experienced during the period before therapy was initiated. The objective of this study was to examine locomotor activity in rats after long-term dopaminergic treatment and its relationship with expression of the D2 receptor, in addition to demonstrating possible evidence of augmentation. The rats were divided into control (CTRL) and drug (Pramipexole—PPX) groups that received daily saline vehicle and PPX treatments, respectively, for 71 days. The locomotor behavior of the animals was evaluated weekly in the Open Field test for 71 days. The expression of the dopamine D2 receptor was evaluated by Western Blot analysis. The animals that received the PPX demonstrated a significant reduction in locomotor activity from day 1 to day 57 and a significant increase in immobility time from day 1 to day 64 relative to baseline values, but these values had returned to baseline levels at 71 days. No changes in the expression of the D2 receptor were demonstrated after treatment with a dopaminergic agonist. This study suggests changes in locomotor activity in rats after long-term PPX treatment that include an immediate reduction of locomotion and an increase in immobilization, and after 64 days, these values returned to baseline levels without evidence of augmentation. In addition, it was not possible to demonstrate a relationship between locomotor activity and the expression of D2 receptors under these conditions. PMID:26483930

The effects of long-term dopaminergic treatment on locomotor behavior in rats

Directory of Open Access Journals (Sweden)

Welinton Alessandro Oliveira de Almeida

2014-12-01

Full Text Available Long-term treatments with dopaminergic agents are associated with adverse effects, including augmentation. Augmentation consists of an exacerbation of restless legs syndrome (a sleep-related movement disorder symptoms during treatment compared to those experienced during the period before therapy was initiated. The objective of this study was to examine locomotor activity in rats after long-term dopaminergic treatment and its relationship with expression of the D2 receptor, in addition to demonstrating possible evidence of augmentation. The rats were divided into control (CTRL and drug (Pramipexole—PPX groups that received daily saline vehicle and PPX treatments, respectively, for 71 days. The locomotor behavior of the animals was evaluated weekly in the Open Field test for 71 days. The expression of the dopamine D2 receptor was evaluated by Western Blot analysis. The animals that received the PPX demonstrated a significant reduction in locomotor activity from day 1 to day 57 and a significant increase in immobility time from day 1 to day 64 relative to baseline values, but these values had returned to baseline levels at 71 days. No changes in the expression of the D2 receptor were demonstrated after treatment with a dopaminergic agonist. This study suggests changes in locomotor activity in rats after long-term PPX treatment that include an immediate reduction of locomotion and an increase in immobilization, and after 64 days, these values returned to baseline levels without evidence of augmentation. In addition, it was not possible to demonstrate a relationship between locomotor activity and the expression of D2 receptors under these conditions.

AMBIDEXTER Dynamics and Self-Regulation Capability

International Nuclear Information System (INIS)

Oh, Se Kee; Lee, Young Joon; Ham, Tae Kyu; Seo, Myung Hwan; Hong, Sung Taek; Kwon, Tae An

2009-01-01

Safety-related events in a nuclear reactor system are mostly incurred by sudden imbalance between their heat source and sink behaviors. Controllability and resiliency are assessed if the system be safely recoverable from the imbalance. Inherent safety characteristics of the reactor should be an ideal design philosophy in this aspect. The AMBIDEXTER safety design was explored with maximum reliance on counteractive responses by the system itself. As for the realization, negative reactivity feedback and fail-safe criteria are the fundamental considerations. Details of how to implement them in the design can be found in the paper accompanied. the reactor and the primary heat exchanger are integrated into a closed loop in the vessel. The fuel salt flows downwardly in the outer core region, gains fission heat and then, rises upwardly through the central inner core region where resonance absorbers face better conversion chance. In the primary heat exchanger, heat transfer between the tube-side fuel salt and the shell-side coolant salt is made. For chemical processing, part of the fuel salt flow is discharged from the heat exchanger and returns to the reactor through bypass line. This paper examines the dynamic performances of the AMBIDEXTER reactor system to investigate the range of its self-regulation capability and safety impacts

Objective and quantitative equilibriometric evaluation of individual locomotor behaviour in schizophrenia: Translational and clinical implications.

Science.gov (United States)

Haralanov, Svetlozar; Haralanova, Evelina; Milushev, Emil; Shkodrova, Diana; Claussen, Claus-Frenz

2018-04-17

Psychiatry is the only medical specialty that lacks clinically applicable biomarkers for objective evaluation of the existing pathology at a single-patient level. On the basis of an original translational equilibriometric method for evaluation of movement patterns, we have introduced in the everyday clinical practice of psychiatry an easy-to-perform computerized objective quantification of the individual locomotor behaviour during execution of the Unterberger stepping test. For the last 20 years, we have gradually collected a large database of more than 1000 schizophrenic patients, their relatives, and matched psychiatric, neurological, and healthy controls via cross-sectional and longitudinal investigations. Comparative analyses revealed transdiagnostic locomotor similarities among schizophrenic patients, high-risk schizotaxic individuals, and neurological patients with multiple sclerosis and cerebellar ataxia, thus suggesting common underlying brain mechanisms. In parallel, intradiagnostic dissimilarities were revealed, which allow to separate out subclinical locomotor subgroups within the diagnostic categories. Prototypical qualitative (dysmetric and ataxic) locomotor abnormalities in schizophrenic patients were differentiated from 2 atypical quantitative ones, manifested as either hypolocomotion or hyperlocomotion. Theoretical analyses suggested that these 3 subtypes of locomotor abnormalities could be conceived as objectively measurable biomarkers of 3 schizophrenic subgroups with dissimilar brain mechanisms, which require different treatment strategies. Analogies with the prominent role of locomotor measures in some well-known animal models of mental disorders advocate for a promising objective translational research in the so far over-subjective field of psychiatry. Distinctions among prototypical, atypical, and diagnostic biomarkers, as well as between neuromotor and psychomotor locomotor abnormalities, are discussed. Conclusions are drawn about the

Early-life risperidone enhances locomotor responses to amphetamine during adulthood.

Science.gov (United States)

Lee Stubbeman, Bobbie; Brown, Clifford J; Yates, Justin R; Bardgett, Mark E

2017-10-05

Antipsychotic drug prescriptions for pediatric populations have increased over the past 20 years, particularly the use of atypical antipsychotic drugs such as risperidone. Most antipsychotic drugs target forebrain dopamine systems, and early-life antipsychotic drug exposure could conceivably reset forebrain neurotransmitter function in a permanent manner that persists into adulthood. This study determined whether chronic risperidone administration during development modified locomotor responses to the dopamine/norepinephrine agonist, D-amphetamine, in adult rats. Thirty-five male Long-Evans rats received an injection of one of four doses of risperidone (vehicle, .3, 1.0, 3.0mg/kg) each day from postnatal day 14 through 42. Locomotor activity was measured for 1h on postnatal days 46 and 47, and then for 24h once a week over the next two weeks. Beginning on postnatal day 75, rats received one of four doses of amphetamine (saline, .3, 1.0, 3.0mg/kg) once a week for four weeks. Locomotor activity was measured for 27h after amphetamine injection. Rats administered risperidone early in life demonstrated increased activity during the 1 and 24h test sessions conducted prior to postnatal day 75. Taking into account baseline group differences, these same rats exhibited significantly more locomotor activity in response to the moderate dose of amphetamine relative to controls. These results suggest that early-life treatment with atypical antipsychotic drugs, like risperidone, permanently alters forebrain catecholamine function and increases sensitivity to drugs that target such function. Copyright © 2017 Elsevier B.V. All rights reserved.

Global dynamics, capabilities and the crisis

Czech Academy of Sciences Publication Activity Database

Fagerberg, J.; Srholec, Martin

2016-01-01

Roč. 26, č. 4 (2016), s. 765-784 ISSN 0936-9937 R&D Projects: GA ČR GAP402/10/2310 Institutional support: RVO:67985998 Keywords : technological capabilities * social capabilities * competitiveness Subject RIV: AH - Economics Impact factor: 0.862, year: 2016

Locomotor recovery after spinal cord contusion injury in rats is improved by spontaneous exercise

NARCIS (Netherlands)

Gispen, W.H.; Meeteren, N.L. van; Eggers, L.; Lankhorst, A.J.; Hamers, F.P.

2003-01-01

We have recently shown that enriched environment (EE) housing significantly enhances locomotor recovery following spinal cord contusion injury (SCI) in rats. As the type and intensity of locomotor training with EE housing are rather poorly characterized, we decided to compare the effectiveness of EE

Towards a dynamic concept of alliance capability

OpenAIRE

SLUYTS, Kim; MARTENS, Rudy; MATTHYSSENS, Paul

2008-01-01

This paper has a threefold purpose. First, we offer a literature review on alliance capability based on strategic and competence based management literature. Second, we extend existing literature on alliance capability by breaking this concept down into five sub capabilities, which are each linked to a stage of the alliance life cycle. Finally, we suggest how firms can support these capabilities through structural, technological and people-related tools and techniques. We argue that current l...

EphA4 defines a class of excitatory locomotor-related interneurons

DEFF Research Database (Denmark)

Butt, S. J B; Lundfald, Line; Kiehn, Ole

2005-01-01

of these interneurons provide direct excitation to ipsilateral motor neurons as determined by spike-triggered averaging of the local ventral root DC trace. Our findings substantiate the role of EphA4-positive interneurons as significant components of the ipsilateral locomotor network and describe a group of putative...... of the role of these cells in the network. One such marker is the EphA4 axon guidance receptor. EphA4-null mice display an abnormal rabbit-like hopping gait that is thought to be the result of synchronization of the normally alternating, bilateral locomotor network via aberrant crossed connections....... In this study, we have performed whole-cell patch clamp on EphA4-positive interneurons in the flexor region (L2) of the locomotor network. We provide evidence that although EphA4 positive interneurons are not entirely a homogeneous population, most of them fire in a rhythmic manner. Moreover, a subset...

Run don't walk: locomotor performance of geckos on wet substrates.

Science.gov (United States)

Stark, Alyssa Y; Ohlemacher, Jocelyn; Knight, Ashley; Niewiarowski, Peter H

2015-08-01

The gecko adhesive system has been under particular scrutiny for over a decade, as the field has recently attracted attention for its application to bio-inspired design. However, little is known about how the adhesive system behaves in ecologically relevant conditions. Geckos inhabit a variety of environments, many of which are characterized by high temperature, humidity and rain. The van der Waals-based gecko adhesive system should be particularly challenged by wet substrates because water can disrupt the intimate contact necessary for adhesion. While a few previous studies have focused on the clinging ability of geckos on wet substrates, we tested a dynamic performance characteristic, sprint velocity. To better understand how substrate wettability and running orientation affect locomotor performance of multiple species on wet substrates, we measured average sprint velocity of five species of gecko on substrates that were either hydrophilic or intermediately wetting and oriented either vertically or horizontally. Surprisingly, we found no indication that wet substrates impact average sprint velocity over 1 m, and rather, in some species, sprint velocity was increased on wet substrates rather than reduced. When investigating physical characteristics and behavior that may be associated with running on wet substrates, such as total number of stops, slips and wet toes at the completion of a race, we found that there may be habitat-related differences between some species. Our results show that in general, unlike clinging and walking, geckos running along wet substrates suffer no significant loss in locomotor performance over short distances. © 2015. Published by The Company of Biologists Ltd.

Plasticity of locomotor sensorimotor interactions after peripheral and/or spinal lesions

DEFF Research Database (Denmark)

Rossignol, Serge; Barrière, Grégory; Frigon, Alain

2008-01-01

The present paper reviews aspects of locomotor sensorimotor interactions by focussing on work performed in spinal cats. We provide a brief overview of spinal locomotion and describe the effects of various types of sensory deprivations (e.g. rhizotomies, and lesions of muscle and cutaneous nerves......) to highlight the spinal neuroplasticity necessary for adapting to sensory loss. Recent work on plastic interactions between reflex pathways that could be responsible for such plasticity, in particular changes in proprioceptive and cutaneous pathways that occur during locomotor training of spinal cats...

Injections of the selective adenosine A2A antagonist MSX-3 into the nucleus accumbens core attenuate the locomotor suppression induced by haloperidol in rats.

Science.gov (United States)

Ishiwari, Keita; Madson, Lisa J; Farrar, Andrew M; Mingote, Susana M; Valenta, John P; DiGianvittorio, Michael D; Frank, Lauren E; Correa, Merce; Hockemeyer, Jörg; Müller, Christa; Salamone, John D

2007-03-28

There is considerable evidence of interactions between adenosine A2A receptors and dopamine D2 receptors in striatal areas, and antagonists of the A2A receptor have been shown to reverse the motor effects of DA antagonists in animal models. The D2 antagonist haloperidol produces parkinsonism in humans, and also induces motor effects in rats, such as suppression of locomotion. The present experiments were conducted to study the ability of the adenosine A2A antagonist MSX-3 to reverse the locomotor effects of acute or subchronic administration of haloperidol in rats. Systemic (i.p.) injections of MSX-3 (2.5-10.0 mg/kg) were capable of attenuating the suppression of locomotion induced by either acute or repeated (i.e., 14 day) administration of 0.5 mg/kg haloperidol. Bilateral infusions of MSX-3 directly into the nucleus accumbens core (2.5 microg or 5.0 microg in 0.5 microl per side) produced a dose-related increase in locomotor activity in rats treated with 0.5 mg/kg haloperidol either acutely or repeatedly. There were no overall significant effects of MSX-3 infused directly into the dorsomedial nucleus accumbens shell or the ventrolateral neostriatum. These results indicate that antagonism of adenosine A2A receptors can attenuate the locomotor suppression produced by DA antagonism, and that this effect may be at least partially mediated by A2A receptors in the nucleus accumbens core. These studies suggest that adenosine and dopamine systems interact to modulate the locomotor and behavioral activation functions of nucleus accumbens core.

Dissociation of corticotropin-releasing factor receptor subtype involvement in sensitivity to locomotor effects of methamphetamine and cocaine.

Science.gov (United States)

Giardino, William J; Mark, Gregory P; Stenzel-Poore, Mary P; Ryabinin, Andrey E

2012-02-01

Enhanced sensitivity to the euphoric and locomotor-activating effects of psychostimulants may influence an individual's predisposition to drug abuse and addiction. While drug-induced behaviors are mediated by the actions of several neurotransmitter systems, past research revealed that the corticotropin-releasing factor (CRF) system is important in driving the acute locomotor response to psychostimulants. We previously reported that genetic deletion of the CRF type-2 receptor (CRF-R2), but not the CRF type-1 receptor (CRF-R1) dampened the acute locomotor stimulant response to methamphetamine (1 mg/kg). These results contrasted with previous studies implicating CRF-R1 in the locomotor effects of psychostimulants. Since the majority of previous studies focused on cocaine, rather than methamphetamine, we set out to test the hypothesis that these drugs differentially engage CRF-R1 and CRF-R2. We expanded our earlier findings by first replicating our previous experiments at a higher dose of methamphetamine (2 mg/kg), and by assessing the effects of the CRF-R1-selective antagonist CP-376,395 (10 mg/kg) on methamphetamine-induced locomotor activity. Next, we used both genetic and pharmacological tools to examine the specific components of the CRF system underlying the acute locomotor response to cocaine (5-10 mg/kg). While genetic deletion of CRF-R2 dampened the locomotor response to methamphetamine (but not cocaine), genetic deletion and pharmacological blockade of CRF-R1 dampened the locomotor response to cocaine (but not methamphetamine). These findings highlight the differential involvement of CRF receptors in acute sensitivity to two different stimulant drugs of abuse, providing an intriguing basis for the development of more targeted therapeutics for psychostimulant addiction.

Initial locomotor sensitivity to cocaine varies widely among inbred mouse strains.

Science.gov (United States)

Wiltshire, T; Ervin, R B; Duan, H; Bogue, M A; Zamboni, W C; Cook, S; Chung, W; Zou, F; Tarantino, L M

2015-03-01

Initial sensitivity to psychostimulants can predict subsequent use and abuse in humans. Acute locomotor activation in response to psychostimulants is commonly used as an animal model of initial drug sensitivity and has been shown to have a substantial genetic component. Identifying the specific genetic differences that lead to phenotypic differences in initial drug sensitivity can advance our understanding of the processes that lead to addiction. Phenotyping inbred mouse strain panels are frequently used as a first step for studying the genetic architecture of complex traits. We assessed locomotor activation following a single, acute 20 mg/kg dose of cocaine (COC) in males from 45 inbred mouse strains and observed significant phenotypic variation across strains indicating a substantial genetic component. We also measured levels of COC, the active metabolite, norcocaine and the major inactive metabolite, benzoylecgonine, in plasma and brain in the same set of inbred strains. Pharmacokinetic (PK) and behavioral data were significantly correlated, but at a level that indicates that PK alone does not account for the behavioral differences observed across strains. Phenotypic data from this reference population of inbred strains can be utilized in studies aimed at examining the role of psychostimulant-induced locomotor activation on drug reward and reinforcement and to test theories about addiction processes. Moreover, these data serve as a starting point for identifying genes that alter sensitivity to the locomotor stimulatory effects of COC. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Efficacy of Static Magnetic Field for Locomotor Activity of Experimental Osteopenia

Directory of Open Access Journals (Sweden)

Norimasa Taniguchi

2007-01-01

Full Text Available In order to examine the effectiveness of applying a static magnetic field (SMF for increasing bone mineral density (BMD, we assessed the degree of osteopenia by dual-energy X-ray absorptiometry (DEXA, the metabolism measuring system, and histological examination of bone tissue in an ovariectomized (OVX rat model. Thirty-six female Wistar rats (8 weeks old, 160–180 g were divided into three groups. The rats in the OVX-M group were exposed to SMF for 12 weeks after ovariectomy. The ovariectomized rats in the OVX-D group were not exposed to SMF as a control. The rats in the normal group received neither ovariectomy nor exposure to SMF. Twelve-week exposure to SMF in the OVX-M group inhibited the reduction in BMD that was observed in the OVX-D group. Moreover, in the OVX rats, before exposure to SMF, there was no clear difference in the level of locomotor activity between the active and resting phases, and the pattern of locomotor activity was irregular. After exposure of OVX rats to SMF, the pattern of locomotor activity became diphasic with clear active and resting phases, as was observed in the normal group. In the OVX-M group, the continuity of the trabecular bone was maintained more favorably and bone mass was higher than the respective parameters in the OVX-D group. These results demonstrate that exposure to SMF increased the level of locomotor activity in OVX rats, thereby increasing BMD.

The Effects of Sex-Ratio and Density on Locomotor Activity in the House Fly, Musca domestica

OpenAIRE

Bahrndorff, Simon; Kjærsgaard, Anders; Pertoldi, Cino; Loeschcke, Volker; Schou, Toke M.; Skovgård, Henrik; Hald, Birthe

2012-01-01

Although locomotor activity is involved in almost all behavioral traits, there is a lack of knowledge on what factors affect it. This study examined the effects of sex-ratio and density on the circadian rhythm of locomotor activity of adult Musca domestica L. (Diptera: Muscidae) using an infra-red light system. Sex-ratio significantly affected locomotor activity, increasing with the percentage of males in the vials. In accordance with other studies, males were more active than females, but th...

Training Delivery Methods as Source of Dynamic Capabilities: The Case of Sports' Organisations

Science.gov (United States)

Arraya, Marco António Mexia; Porfírio, Jose António

2017-01-01

Purpose: Training as an important source of dynamic capabilities (DC) is important to the performance of sports' organisations (SO) both to athletes and to non-athletic staff. There are a variety of training delivery methods (TDMs). The purpose of this study is to determine from a set of six TDMs which one is considered to be the most suitable to…

Osteological postcranial traits in hylid anurans indicate a morphological continuum between swimming and jumping locomotor modes.

Science.gov (United States)

Soliz, Mónica; Tulli, Maria J; Abdala, Virginia

2017-03-01

Anurans exhibit a particularly wide range of locomotor modes that result in wide variations in their skeletal structure. This article investigates the possible correlation between morphological aspects of the hylid postcranial skeleton and their different locomotor modes and habitat use. To do so, we analyzed 18 morphometric postcranial variables in 19 different anuran species representative of a variety of locomotor modes (jumper, hopper, walker, and swimmer) and habitat uses (arboreal, bush, terrestrial, and aquatic). Our results show that the evolution of the postcranial hylid skeleton cannot be explained by one single model, as for example, the girdles suggest modular evolution while the vertebral column suggests other evolutionary modules. In conjunction with data from several other studies, we were able to show a relationship between hylid morphology and habitat use; offering further evidence that the jumper/swimmer and walker/hopper locomotor modes exhibit quite similar morphological architecture. This allowed us to infer that new locomotor modalities are, in fact, generated along a morphological continuum. J. Morphol. 278:403-417, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

CRFR1 in the ventromedial caudate putamen modulates acute stress-enhanced expression of cocaine locomotor sensitization.

Science.gov (United States)

Liu, Shuli; Wang, Zhiyan; Li, Yijing; Sun, Xiaowei; Ge, Feifei; Yang, Mingda; Wang, Xinjuan; Wang, Na; Wang, Junkai; Cui, Cailian

2017-07-15

Repeated exposure to psychostimulants induces a long-lasting enhancement of locomotor activity called behavioral sensitization, which is often reinforced by stress after drug withdrawal. The mechanisms underlying these phenomena remain elusive. Here we explored the effects of acute stress 3 or 14 days after the cessation of chronic cocaine treatment on the expression of locomotor sensitization induced by a cocaine challenge in rats and the key brain region and molecular mechanism underlying the phenomenon. A single session of forced swimming, as an acute stress (administered 2 days after the cessation of cocaine), significantly enhanced the expression of cocaine locomotor sensitization 14 days after the final cocaine injection (challenge at 12 days after acute stress) but not 3 days after the cessation of cocaine (challenge at 1 day after acute stress). The result indicated that acute stress enhanced the expression of cocaine locomotor sensitization after incubation for 12 days rather than 1 day after the last cocaine injection. Moreover, the enhancement in locomotor sensitization was paralleled by a selective increase in the number of the c-Fos + cells, the level of CRFR1 mRNA in the ventromedial caudate putamen (vmCPu). Furthermore, the enhancement was significantly attenuated by CRFR1 antagonist NBI-27914 into the vmCPu, implying that the up-regulation of CRFR1 in the vmCPu seems to be critical in the acute stress-enhanced expression of cocaine locomotor sensitization. The findings demonstrate that the long-term effect of acute stress on the expression of cocaine locomotor sensitization is partially mediated by CRFR1 in the vmCPu. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Development and functional organization of spinal locomotor circuits

DEFF Research Database (Denmark)

Kiehn, Ole

2011-01-01

The coordination and timing of muscle activities during rhythmic movements, like walking and swimming, are generated by intrinsic spinal motor circuits. Such locomotor networks are operational early in development and are found in all vertebrates. This review outlines and compares recent advances...

Motor unit recruitment patterns 1: responses to changes in locomotor velocity and incline.

Science.gov (United States)

Hodson-Tole, Emma F; Wakeling, James M

2008-06-01

Mammalian skeletal muscles are composed of a mixture of motor unit types, which contribute a range of mechanical and physiological properties to the muscle. For a muscle to effectively contribute to smooth, co-ordinated movement it must activate an appropriate number and combination of motor units to generate the required force over a suitable time period. Much evidence exists indicating that motor units are activated in an orderly fashion, from the slowest through to the fastest. A growing body of evidence, however, indicates that such a recruitment strategy does not always hold true. Here we investigate how motor unit recruitment patterns were influenced by changes in locomotor velocity and incline. Kinematics data and myoelectric signals were collected from three rat ankle extensor muscles during running on a treadmill at nine velocity and incline combinations. Wavelet and principal component analysis were used to simultaneously decompose the signals into time and frequency space. The relative frequency components of the signals were quantified during 20 time windows of a stride from each locomotor condition. Differences in signal frequency components existed between muscles and locomotor conditions. Faster locomotor velocities led to a relative increase in high frequency components, whereas greater inclines led to a relative increase in the low frequency components. These data were interpreted as representing changes in motor unit recruitment patterns in response to changes in the locomotor demand. Motor units were not always recruited in an orderly manner, indicating that recruitment is a multi-factorial phenomenon that is not yet fully understood.

Ankle voluntary movement enhancement following robotic-assisted locomotor training in spinal cord injury

OpenAIRE

Varoqui, Deborah; Niu, Xun; Mirbagheri, Mehdi M

2014-01-01

Background In incomplete spinal cord injury (iSCI), sensorimotor impairments result in severe limitations to ambulation. To improve walking capacity, physical therapies using robotic-assisted locomotor devices, such as the Lokomat, have been developed. Following locomotor training, an improvement in gait capabilities—characterized by increases in the over-ground walking speed and endurance—is generally observed in patients. To better understand the mechanisms underlying these improvements, we...

Differences in the locomotor-activating effects of indirect serotonin agonists in habituated and non-habituated rats.

Science.gov (United States)

Halberstadt, Adam L; Buell, Mahálah R; Price, Diana L; Geyer, Mark A

2012-07-01

The indirect serotonin (5-HT) agonist 3,4-methylenedioxymethamphetamine (MDMA) produces a distinct behavioral profile in rats consisting of locomotor hyperactivity, thigmotaxis, and decreased exploration. The indirect 5-HT agonist α-ethyltryptamine (AET) produces a similar behavioral profile. Using the Behavioral Pattern Monitor (BPM), the present investigation examined whether the effects of MDMA and AET are dependent on the novelty of the testing environment. These experiments were conducted in Sprague-Dawley rats housed on a reversed light cycle and tested during the dark phase of the light/dark cycle. We found that racemic MDMA (RS-MDMA; 3 mg/kg, SC) increased locomotor activity in rats tested in novel BPM chambers, but had no effect on locomotor activity in rats habituated to the BPM chambers immediately prior to testing. Likewise, AET (5 mg/kg, SC) increased locomotor activity in non-habituated animals but not in animals habituated to the test chambers. These results were unexpected because previous reports indicate that MDMA has robust locomotor-activating effects in habituated animals. To further examine the influence of habituation on MDMA-induced locomotor activity, we conducted parametric studies with S-(+)-MDMA (the more active enantiomer) in habituated and non-habituated rats housed on a standard or reversed light cycle. Light cycle was included as a variable due to reported differences in sensitivity to serotonergic ligands during the dark and light phases. In confirmation of our initial studies, rats tested during the dark phase and habituated to the BPM did not show an S-(+)-MDMA (3 mg/kg, SC)-induced increase in locomotor activity, whereas non-habituated rats did. By contrast, in rats tested during the light phase, S-(+)-MDMA increased locomotor activity in both non-habituated and habituated rats, although the response in habituated animals was attenuated. The finding that habituation and light cycle interact to influence MDMA- and AET

Error signals driving locomotor adaptation

DEFF Research Database (Denmark)

Choi, Julia T; Jensen, Peter; Nielsen, Jens Bo

2016-01-01

Locomotor patterns must be adapted to external forces encountered during daily activities. The contribution of different sensory inputs to detecting perturbations and adapting movements during walking is unclear. Here we examined the role of cutaneous feedback in adapting walking patterns to force...... walking (Choi et al. 2013). Sensory tests were performed to measure cutaneous touch threshold and perceptual threshold of force perturbations. Ankle movement were measured while subjects walked on the treadmill over three periods: baseline (1 min), adaptation (1 min) and post-adaptation (3 min). Subjects...

The evolution of locomotor rhythmicity in tetrapods.

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Ross, Callum F; Blob, Richard W; Carrier, David R; Daley, Monica A; Deban, Stephen M; Demes, Brigitte; Gripper, Janaya L; Iriarte-Diaz, Jose; Kilbourne, Brandon M; Landberg, Tobias; Polk, John D; Schilling, Nadja; Vanhooydonck, Bieke

2013-04-01

Differences in rhythmicity (relative variance in cycle period) among mammal, fish, and lizard feeding systems have been hypothesized to be associated with differences in their sensorimotor control systems. We tested this hypothesis by examining whether the locomotion of tachymetabolic tetrapods (birds and mammals) is more rhythmic than that of bradymetabolic tetrapods (lizards, alligators, turtles, salamanders). Species averages of intraindividual coefficients of variation in cycle period were compared while controlling for gait and substrate. Variance in locomotor cycle periods is significantly lower in tachymetabolic than in bradymetabolic animals for datasets that include treadmill locomotion, non-treadmill locomotion, or both. When phylogenetic relationships are taken into account the pooled analyses remain significant, whereas the non-treadmill and the treadmill analyses become nonsignificant. The co-occurrence of relatively high rhythmicity in both feeding and locomotor systems of tachymetabolic tetrapods suggests that the anatomical substrate of rhythmicity is in the motor control system, not in the musculoskeletal components. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Manipulation of dopamine metabolism contributes to attenuating innate high locomotor activity in ICR mice.

Science.gov (United States)

Yamaguchi, Takeshi; Nagasawa, Mao; Ikeda, Hiromi; Kodaira, Momoko; Minaminaka, Kimie; Chowdhury, Vishwajit S; Yasuo, Shinobu; Furuse, Mitsuhiro

2017-06-15

Attention-deficit hyperactivity disorder (ADHD) is defined as attention deficiency, restlessness and distraction. The main characteristics of ADHD are hyperactivity, impulsiveness and carelessness. There is a possibility that these abnormal behaviors, in particular hyperactivity, are derived from abnormal dopamine (DA) neurotransmission. To elucidate the mechanism of high locomotor activity, the relationship between innate activity levels and brain monoamines and amino acids was investigated in this study. Differences in locomotor activity between ICR, C57BL/6J and CBA/N mice were determined using the open field test. Among the three strains, ICR mice showed the greatest amount of locomotor activity. The level of striatal and cerebellar DA was lower in ICR mice than in C57BL/6J mice, while the level of L-tyrosine (L-Tyr), a DA precursor, was higher in ICR mice. These results suggest that the metabolic conversion of L-Tyr to DA is lower in ICR mice than it is in C57BL/6J mice. Next, the effects of intraperitoneal injection of (6R)-5, 6, 7, 8-tetrahydro-l-biopterin dihydrochloride (BH 4 ) (a co-enzyme for tyrosine hydroxylase) and L-3,4-dihydroxyphenylalanine (L-DOPA) on DA metabolism and behavior in ICR mice were investigated. The DA level in the brain was increased by BH 4 administration, but the increased DA did not influence behavior. However, L-DOPA administration drastically lowered locomotor activity and increased DA concentration in several parts of the brain. The reduced locomotor activity may have been a consequence of the overproduction of DA. In conclusion, the high level of locomotor activity in ICR mice may be explained by a strain-specific DA metabolism. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of respiratory muscle work on respiratory and locomotor blood flow during exercise.

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Dominelli, Paolo B; Archiza, Bruno; Ramsook, Andrew H; Mitchell, Reid A; Peters, Carli M; Molgat-Seon, Yannick; Henderson, William R; Koehle, Michael S; Boushel, Robert; Sheel, A William

2017-11-01

What is the central question of this study? Does manipulation of the work of breathing during high-intensity exercise alter respiratory and locomotor muscle blood flow? What is the main finding and its importance? We found that when the work of breathing was reduced during exercise, respiratory muscle blood flow decreased, while locomotor muscle blood flow increased. Conversely, when the work of breathing was increased, respiratory muscle blood flow increased, while locomotor muscle blood flow decreased. Our findings support the theory of a competitive relationship between locomotor and respiratory muscles during intense exercise. Manipulation of the work of breathing (WOB) during near-maximal exercise influences leg blood flow, but the effects on respiratory muscle blood flow are equivocal. We sought to assess leg and respiratory muscle blood flow simultaneously during intense exercise while manipulating WOB. Our hypotheses were as follows: (i) increasing the WOB would increase respiratory muscle blood flow and decrease leg blood flow; and (ii) decreasing the WOB would decrease respiratory muscle blood flow and increase leg blood flow. Eight healthy subjects (n = 5 men, n = 3 women) performed a maximal cycle test (day 1) and a series of constant-load exercise trials at 90% of peak work rate (day 2). On day 2, WOB was assessed with oesophageal balloon catheters and was increased (via resistors), decreased (via proportional assist ventilation) or unchanged (control) during the trials. Blood flow was assessed using near-infrared spectroscopy optodes placed over quadriceps and the sternocleidomastoid muscles, coupled with a venous Indocyanine Green dye injection. Changes in WOB were significantly and positively related to changes in respiratory muscle blood flow (r = 0.73), whereby increasing the WOB increased blood flow. Conversely, changes in WOB were significantly and inversely related to changes in locomotor blood flow (r = 0.57), whereby decreasing the

A Model of Locomotor-Respiratory Coupling in Quadrupeds

Science.gov (United States)

Giuliodori,, Mauricio J.; Lujan, Heidi L.; Briggs, Whitney S.; DiCarlo, Stephen E.

2009-01-01

Locomotion and respiration are not independent phenomena in running mammals because locomotion and respiration both rely on cyclic movements of the ribs, sternum, and associated musculature. Thus, constraints are imposed on locomotor and respiratory function by virtue of their linkage. Specifically, locomotion imposes mechanical constraints on…

Locomotor differences in Mongolian gerbils with the effects of ...

African Journals Online (AJOL)

Locomotor differences in Mongolian gerbils with the effects of midazolam ... African Health Sciences ... We subjected the gerbils to an adapted “Open Field” to determine the possible effects on central nervous system of midazolam. Gerbils ...

Decrease of GSK3β phosphorylation in the rat nucleus accumbens core enhances cocaine-induced hyper-locomotor activity.

Science.gov (United States)

Kim, Wha Y; Jang, Ju K; Lee, Jung W; Jang, Hyunduk; Kim, Jeong-Hoon

2013-06-01

Glycogen synthase kinase 3β (GSK3β), which is abundantly present in the brain, is known to contribute to psychomotor stimulant-induced locomotor behaviors. However, most studies have been focused in showing that GSK3β is able to attenuate psychomotor stimulants-induced hyperactivity by increasing its phosphorylation levels in the nucleus accumbens (NAcc). So, here we examined in the opposite direction about the effects of decreased phosphorylation of GSK3β in the NAcc core on both basal and cocaine-induced locomotor activity by a bilateral microinjection into this site of an artificially synthesized peptide, S9 (0.5 or 5.0 μg/μL), which contains sequences around N-terminal serine 9 residue of GSK3β. We found that decreased levels of GSK3β phosphorylation in the NAcc core enhance cocaine-induced hyper-locomotor activity, while leaving basal locomotor activity unchanged. This is the first demonstration, to our knowledge, that the selective decrease of GSK3β phosphorylation levels in the NAcc core may contribute positively to cocaine-induced locomotor activity, while this is not sufficient for the generation of locomotor behavior by itself without cocaine. Taken together, these findings importantly suggest that GSK3β may need other molecular targets which are co-activated (or deactivated) by psychomotor stimulants like cocaine to contribute to generation of locomotor behaviors. © 2013 International Society for Neurochemistry.

Shared human-chimpanzee pattern of perinatal femoral shaft morphology and its implications for the evolution of hominin locomotor adaptations.

Directory of Open Access Journals (Sweden)

Naoki Morimoto

Full Text Available Acquisition of bipedality is a hallmark of human evolution. How bipedality evolved from great ape-like locomotor behaviors, however, is still highly debated. This is mainly because it is difficult to infer locomotor function, and even more so locomotor kinematics, from fossil hominin long bones. Structure-function relationships are complex, as long bone morphology reflects phyletic history, developmental programs, and loading history during an individual's lifetime. Here we discriminate between these factors by investigating the morphology of long bones in fetal and neonate great apes and humans, before the onset of locomotion.Comparative morphometric analysis of the femoral diaphysis indicates that its morphology reflects phyletic relationships between hominoid taxa to a greater extent than taxon-specific locomotor adaptations. Diaphyseal morphology in humans and chimpanzees exhibits several shared-derived features, despite substantial differences in locomotor adaptations. Orangutan and gorilla morphologies are largely similar, and likely represent the primitive hominoid state.These findings are compatible with two possible evolutionary scenarios. Diaphyseal morphology may reflect retained adaptive traits of ancestral taxa, hence human-chimpanzee shared-derived features may be indicative of the locomotor behavior of our last common ancestor. Alternatively, diaphyseal morphology might reflect evolution by genetic drift (neutral evolution rather than selection, and might thus be more informative about phyletic relationships between taxa than about locomotor adaptations. Both scenarios are consistent with the hypothesis that knuckle-walking in chimpanzees and gorillas resulted from convergent evolution, and that the evolution of human bipedality is unrelated to extant great ape locomotor specializations.

Hesperidin effects on behavior and locomotor activity of diabetic ...

African Journals Online (AJOL)

Tuoyo Aghomotsegin

2016-11-09

Nov 9, 2016 ... Author(s) agree that this article remains permanently open access under the terms of the Creative ... diabetes in animals and patients with type1 (Northam et ... measured were, locomotor activities, standing position, the time of.

Locomotor performance of cane toads differs between native-range and invasive populations.

Science.gov (United States)

Kosmala, Georgia; Christian, Keith; Brown, Gregory; Shine, Richard

2017-07-01

Invasive species provide a robust opportunity to evaluate how animals deal with novel environmental challenges. Shifts in locomotor performance-and thus the ability to disperse-(and especially, the degree to which it is constrained by thermal and hydric extremes) are of special importance, because they might affect the rate that an invader can spread. We studied cane toads ( Rhinella marina ) across a broad geographical range: two populations within the species' native range in Brazil, two invasive populations on the island of Hawai'i and eight invasive populations encompassing the eastern, western and southern limits of the toad invasion in Australia. A toad's locomotor performance on a circular raceway was strongly affected by both its temperature and its hydration state, but the nature and magnitude of those constraints differed across populations. In their native range, cane toads exhibited relatively low performance (even under optimal test conditions) and a rapid decrease in performance at lower temperatures and hydration levels. At the other extreme, performance was high in toads from southern Australia, and virtually unaffected by desiccation. Hawai'ian toads broadly resembled their Brazilian conspecifics, plausibly reflecting similar climatic conditions. The invasion of Australia has been accompanied by a dramatic enhancement in the toads' locomotor abilities, and (in some populations) by an ability to maintain locomotor performance even when the animal is cold and/or dehydrated. The geographical divergences in performance among cane toad populations graphically attest to the adaptability of invasive species in the face of novel abiotic challenges.

Kokkos' Task DAG Capabilities.

Energy Technology Data Exchange (ETDEWEB)

Edwards, Harold C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ibanez, Daniel Alejandro [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-09-01

This report documents the ASC/ATDM Kokkos deliverable "Production Portable Dy- namic Task DAG Capability." This capability enables applications to create and execute a dynamic task DAG ; a collection of heterogeneous computational tasks with a directed acyclic graph (DAG) of "execute after" dependencies where tasks and their dependencies are dynamically created and destroyed as tasks execute. The Kokkos task scheduler executes the dynamic task DAG on the target execution resource; e.g. a multicore CPU, a manycore CPU such as Intel's Knights Landing (KNL), or an NVIDIA GPU. Several major technical challenges had to be addressed during development of Kokkos' Task DAG capability: (1) portability to a GPU with it's simplified hardware and micro- runtime, (2) thread-scalable memory allocation and deallocation from a bounded pool of memory, (3) thread-scalable scheduler for dynamic task DAG, (4) usability by applications.

The peacock train does not handicap cursorial locomotor performance

Science.gov (United States)

Thavarajah, Nathan K.; Tickle, Peter G.; Nudds, Robert L.; Codd, Jonathan R.

2016-01-01

Exaggerated traits, like the peacock train, are recognized as classic examples of sexual selection. The evolution of sexual traits is often considered paradoxical as, although they enhance reproductive success, they are widely presumed to hinder movement and survival. Many exaggerated traits represent an additional mechanical load that must be carried by the animal and therefore may influence the metabolic cost of locomotion and constrain locomotor performance. Here we conducted respirometry experiments on peacocks and demonstrate that the exaggerated sexually selected train does not compromise locomotor performance in terms of the metabolic cost of locomotion and its kinematics. Indeed, peacocks with trains had a lower absolute and mass specific metabolic cost of locomotion. Our findings suggest that adaptations that mitigate any costs associated with exaggerated morphology are central in the evolution of sexually selected traits. PMID:27805067

GABAB Receptor Stimulation Accentuates the Locomotor Effects of Morphine in Mice Bred for Extreme Sensitivity to the Stimulant Effects of Ethanol

OpenAIRE

Holstein, Sarah E.; Phillips, Tamara J.

2006-01-01

Mice selectively bred for divergent sensitivity to the locomotor stimulant effects of ethanol (FAST and SLOW) also differ in their locomotor response to morphine. The GABAB receptor has been implicated in the mediation of locomotor stimulation to both ethanol and morphine, and a reduction in ethanol-induced stimulation has been found with the GABAB receptor agonist baclofen in FAST mice. We hypothesized that GABAB receptor activation would also attenuate the locomotor stimulant responses to m...

Training Enhances Both Locomotor and Cognitive Adaptability to a Novel Sensory Environment

Science.gov (United States)

Bloomberg, J. J.; Peters, B. T.; Mulavara, A. P.; Brady, R. A.; Batson, C. D.; Ploutz-Snyder, R. J.; Cohen, H. S.

2010-01-01

During adaptation to novel gravitational environments, sensorimotor disturbances have the potential to disrupt the ability of astronauts to perform required mission tasks. The goal of this project is to develop a sensorimotor adaptability (SA) training program to facilitate rapid adaptation. We have developed a unique training system comprised of a treadmill placed on a motion-base facing a virtual visual scene that provides an unstable walking surface combined with incongruent visual flow designed to enhance sensorimotor adaptability. The goal of our present study was to determine if SA training improved both the locomotor and cognitive responses to a novel sensory environment and to quantify the extent to which training would be retained. Methods: Twenty subjects (10 training, 10 control) completed three, 30-minute training sessions during which they walked on the treadmill while receiving discordant support surface and visual input. Control subjects walked on the treadmill but did not receive any support surface or visual alterations. To determine the efficacy of training all subjects performed the Transfer Test upon completion of training. For this test, subjects were exposed to novel visual flow and support surface movement, not previously experienced during training. The Transfer Test was performed 20 minutes, 1 week, 1, 3 and 6 months after the final training session. Stride frequency, auditory reaction time, and heart rate data were collected as measures of postural stability, cognitive effort and anxiety, respectively. Results: Using mixed effects regression methods we determined that subjects who received SA training showed less alterations in stride frequency, auditory reaction time and heart rate compared to controls. Conclusion: Subjects who received SA training improved performance across a number of modalities including enhanced locomotor function, increased multi-tasking capability and reduced anxiety during adaptation to novel discordant sensory

Organization of left-right coordination in the mammalian locomotor network

DEFF Research Database (Denmark)

Butt, S. J B; Lebret, James M.; Kiehn, Ole

2002-01-01

in the spinal cords of a number of aquatic vertebrates including the Xenopus tadpole and the lamprey. However, their function in left-right coordination of limb movements in mammals is poorly understood. In this review we describe the present understanding of commissural pathways in the functioning of spinal......Neuronal circuits involved in left-right coordination are a fundamental feature of rhythmic locomotor movements. These circuits necessarily include commissural interneurons (CINs) that have axons crossing the midline of the spinal cord. The properties of CINs have been described in some detail....... Spinal CINs play an important role in the generation of locomotor output. Increased knowledge as to their function in producing locomotion is likely to provide valuable insights into the spinal networks required for postural control and walking....

Descending propriospinal neurons mediate restoration of locomotor function following spinal cord injury

Science.gov (United States)

Benthall, Katelyn N.; Hough, Ryan A.

2016-01-01

Following spinal cord injury (SCI) in the lamprey, there is virtually complete recovery of locomotion within a few weeks, but interestingly, axonal regeneration of reticulospinal (RS) neurons is mostly limited to short distances caudal to the injury site. To explain this situation, we hypothesize that descending propriospinal (PS) neurons relay descending drive from RS neurons to indirectly activate spinal central pattern generators (CPGs). In the present study, the contributions of PS neurons to locomotor recovery were tested in the lamprey following SCI. First, long RS neuron projections were interrupted by staggered spinal hemitransections on the right side at 10% body length (BL; normalized from the tip of the oral hood) and on the left side at 30% BL. For acute recovery conditions (≤1 wk) and before axonal regeneration, swimming muscle burst activity was relatively normal, but with some deficits in coordination. Second, lampreys received two spaced complete spinal transections, one at 10% BL and one at 30% BL, to interrupt long-axon RS neuron projections. At short recovery times (3–5 wk), RS and PS neurons will have regenerated their axons for short distances and potentially established a polysynaptic descending command pathway. At these short recovery times, swimming muscle burst activity had only minor coordination deficits. A computer model that incorporated either of the two spinal lesions could mimic many aspects of the experimental data. In conclusion, descending PS neurons are a viable mechanism for indirect activation of spinal locomotor CPGs, although there can be coordination deficits of locomotor activity. NEW & NOTEWORTHY In the lamprey following spinal lesion-mediated interruption of long axonal projections of reticulospinal (RS) neurons, sensory stimulation still elicited relatively normal locomotor muscle burst activity, but with some coordination deficits. Computer models incorporating the spinal lesions could mimic many aspects of the

Descending propriospinal neurons mediate restoration of locomotor function following spinal cord injury.

Science.gov (United States)

Benthall, Katelyn N; Hough, Ryan A; McClellan, Andrew D

2017-01-01

Following spinal cord injury (SCI) in the lamprey, there is virtually complete recovery of locomotion within a few weeks, but interestingly, axonal regeneration of reticulospinal (RS) neurons is mostly limited to short distances caudal to the injury site. To explain this situation, we hypothesize that descending propriospinal (PS) neurons relay descending drive from RS neurons to indirectly activate spinal central pattern generators (CPGs). In the present study, the contributions of PS neurons to locomotor recovery were tested in the lamprey following SCI. First, long RS neuron projections were interrupted by staggered spinal hemitransections on the right side at 10% body length (BL; normalized from the tip of the oral hood) and on the left side at 30% BL. For acute recovery conditions (≤1 wk) and before axonal regeneration, swimming muscle burst activity was relatively normal, but with some deficits in coordination. Second, lampreys received two spaced complete spinal transections, one at 10% BL and one at 30% BL, to interrupt long-axon RS neuron projections. At short recovery times (3-5 wk), RS and PS neurons will have regenerated their axons for short distances and potentially established a polysynaptic descending command pathway. At these short recovery times, swimming muscle burst activity had only minor coordination deficits. A computer model that incorporated either of the two spinal lesions could mimic many aspects of the experimental data. In conclusion, descending PS neurons are a viable mechanism for indirect activation of spinal locomotor CPGs, although there can be coordination deficits of locomotor activity. In the lamprey following spinal lesion-mediated interruption of long axonal projections of reticulospinal (RS) neurons, sensory stimulation still elicited relatively normal locomotor muscle burst activity, but with some coordination deficits. Computer models incorporating the spinal lesions could mimic many aspects of the experimental results

Flexibility in the patterning and control of axial locomotor networks in lamprey.

Science.gov (United States)

Buchanan, James T

2011-12-01

In lower vertebrates, locomotor burst generators for axial muscles generally produce unitary bursts that alternate between the two sides of the body. In lamprey, a lower vertebrate, locomotor activity in the axial ventral roots of the isolated spinal cord can exhibit flexibility in the timings of bursts to dorsally-located myotomal muscle fibers versus ventrally-located myotomal muscle fibers. These episodes of decreased synchrony can occur spontaneously, especially in the rostral spinal cord where the propagating body waves of swimming originate. Application of serotonin, an endogenous spinal neurotransmitter known to presynaptically inhibit excitatory synapses in lamprey, can promote decreased synchrony of dorsal-ventral bursting. These observations suggest the possible existence of dorsal and ventral locomotor networks with modifiable coupling strength between them. Intracellular recordings of motoneurons during locomotor activity provide some support for this model. Pairs of motoneurons innervating myotomal muscle fibers of similar ipsilateral dorsoventral location tend to have higher correlations of fast synaptic activity during fictive locomotion than do pairs of motoneurons innervating myotomes of different ipsilateral dorsoventral locations, suggesting their control by different populations of premotor interneurons. Further, these different motoneuron pools receive different patterns of excitatory and inhibitory inputs from individual reticulospinal neurons, conveyed in part by different sets of premotor interneurons. Perhaps, then, the locomotor network of the lamprey is not simply a unitary burst generator on each side of the spinal cord that activates all ipsilateral body muscles simultaneously. Instead, the burst generator on each side may comprise at least two coupled burst generators, one controlling motoneurons innervating dorsal body muscles and one controlling motoneurons innervating ventral body muscles. The coupling strength between these two

A single exercise bout and locomotor learning after stroke: physiological, behavioural, and computational outcomes.

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Charalambous, Charalambos C; Alcantara, Carolina C; French, Margaret A; Li, Xin; Matt, Kathleen S; Kim, Hyosub E; Morton, Susanne M; Reisman, Darcy S

2018-05-15

Previous work demonstrated an effect of a single high-intensity exercise bout coupled with motor practice on the retention of a newly acquired skilled arm movement, in both neurologically intact and impaired adults. In the present study, using behavioural and computational analyses we demonstrated that a single exercise bout, regardless of its intensity and timing, did not increase the retention of a novel locomotor task after stroke. Considering both present and previous work, we postulate that the benefits of exercise effect may depend on the type of motor learning (e.g. skill learning, sensorimotor adaptation) and/or task (e.g. arm accuracy-tracking task, walking). Acute high-intensity exercise coupled with motor practice improves the retention of motor learning in neurologically intact adults. However, whether exercise could improve the retention of locomotor learning after stroke is still unknown. Here, we investigated the effect of exercise intensity and timing on the retention of a novel locomotor learning task (i.e. split-belt treadmill walking) after stroke. Thirty-seven people post stroke participated in two sessions, 24 h apart, and were allocated to active control (CON), treadmill walking (TMW), or total body exercise on a cycle ergometer (TBE). In session 1, all groups exercised for a short bout (∼5 min) at low (CON) or high (TMW and TBE) intensity and before (CON and TMW) or after (TBE) the locomotor learning task. In both sessions, the locomotor learning task was to walk on a split-belt treadmill in a 2:1 speed ratio (100% and 50% fast-comfortable walking speed) for 15 min. To test the effect of exercise on 24 h retention, we applied behavioural and computational analyses. Behavioural data showed that neither high-intensity group showed greater 24 h retention compared to CON, and computational data showed that 24 h retention was attributable to a slow learning process for sensorimotor adaptation. Our findings demonstrated that acute exercise

The possible interaction of dopamine system in nucleus accumbens shell and glutamate system of prelimbic region on locomotor activity in rat

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Hatam Ahmadi

2013-06-01

Full Text Available Background: Nucleus accumbens (NAc and prefrontal cortex (PFC dopaminergic and glutamatergic systems are involved in regulating of locomotor activity behaviors. This study has investigated the interaction of NAc shell dopaminergic system and prelimbic glutamatergic systems in regulating locomotor activity and related parameters. Methods: The aim of this study was the effect the drugs injection interaction in the brain of male Wistar rats on locomotor activity and related parameters, in the order of this purpose, open field apparatus that automatically recorded locomotor activity was employed. Unilateral intra-cerebral injection of drugs was done. Results: Unilateral intra-prelimbic injection of D-AP7 (N-methyl-D-aspartic acid= NMDA receptor antagonist; 0.25, 0.5 and 1μg/μl did not alter locomotor activity behaviors. However, infusion of NMDA (0.9μg/μl in this region increased locomotor activity (P<0.01, whereas decreased rearing (P<0.01 and grooming (P<0.01 which was blocked by D-AP7 (0.25μg/μl (P<0.01. Moreover, unilateral infusion of SCH23390 (dopamine D1 receptor antagonist; 0.25, 0.5 and 1μg/μl into the left NAc shell did not alter locomotor activity. However, injection of SKF38393 (dopamine D1 receptor agonist; 4μg/μl into the left NAc shell increased locomotor activity (P<0.05 which was blocked by SCH23390 (0.25μg/μl (P<0.01. Furthermore, the subthreshold dose infusion of SCH23390 (0.25μg/μl into the left NAc shell reduced the effect of intra- prelimbic NMDA on locomotor activity (P<0.01. In addition, intra-NAc shell administration of the subthreshold dose of SKF38393 (1μg/μl potentiated the middle dose (P<0.05, whereas decreased the higher dose of intra-left prelimbic NMDA response (P<0.05 on locomotor activity. Conclusion: The results suggested a modulatory effect of the NAc shell dopaminergic system on increased locomotor activity by activating glutamate system in prelimbic.

Results of clinical and radiologic mass-screening tests of the locomotor system of miners in Hungary

Energy Technology Data Exchange (ETDEWEB)

Bene, E.; Temesvary, P.; Szilagyi, M.; Pera, F.

Clinical and radiological screening tests on the locomotor system of 250 workers being active in mines were accomplished by the authors. The test results of 125 miners working underground were compared with those of a control group consisting of equally 125 workers of the same age category, but engaged in open mining. As a result of the investigation it could be stated that miners working in underground mines were affected by diseases of the organs of motion at a very early stage, and in a greater proportion. The most serious deformations were observed with development irregularities and development variations. The development of degenerative locomotor diseases is promoted in Hungary by the working conditions prevailing underground. The completion of the examination procedure of fitness for work by clinical and radiological examinations of the locomotor system is important and highly recommended. The investigation carried out by the authors may serve as a model for the screening tests to be made on the locomotor system of industrial workers.

Effect of Environmental Conditions and Toxic Compounds on the Locomotor Activity of Pediculus humanus capitis (Phthiraptera: Pediculidae).

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Ortega-Insaurralde, I; Toloza, A C; Gonzalez-Audino, P; Mougabure-Cueto, G A; Alvarez-Costa, A; Roca-Acevedo, G; Picollo, M I

2015-09-01

In this work, we evaluated the effect of environmental variables such as temperature, humidity, and light on the locomotor activity of Pediculus humanus capitis. In addition, we used selected conditions of temperature, humidity, and light to study the effects of cypermethrin and N,N-diethyl-3-methylbenzamide (DEET) on the locomotor activity of head lice. Head lice increased their locomotor activity in an arena at 30°C compared with activity at 20°C. When we tested the influence of the humidity level, the locomotor activity of head lice showed no significant differences related to humidity level, both at 30°C and 20°C. Concerning light influence, we observed that the higher the intensity of light, the slower the movement of head lice. We also demonstrated that sublethal doses of toxics may alter locomotor activity in adults of head lice. Sublethal doses of cypermethrin induced hyperactivated responses in adult head lice. Sublethal doses of DEET evocated hypoactivated responses in head lice. The observation of stereotyped behavior in head lice elicited by toxic compounds proved that measuring locomotor activity in an experimental set-up where environmental conditions are controlled would be appropriate to evaluate compounds of biological importance, such as molecules involved in the host-parasite interaction and intraspecific relationships. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Organizational flexibility as a strategic option: fostering dynamic capabilities of hospitals.

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Dias, Casimiro; Escoval, Ana

2014-01-01

The main purpose of this article is to examine how the internal and external dimensions of organizational flexibility impact hospital performance. Results reveal that matching internal and external flexibilities contributes to the development of capabilities to adopt new strategic options. Such interactions have a significant impact in terms of hospital performance. A cluster of dynamic hospitals, which is characterised by high levels of both internal and external flexibilities, (instead of that have high levels of both internal and external flexibilities) was found to have the double level of performance compared with other clusters. The implications for research and managerial practice are discussed. Copyright © 2014 Longwoods Publishing.

A Dynamic Behaviour Analysis on the Frequency Control Capability of Electric Vehicles

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Zarogiannis, Athanasios; Marinelli, Mattia; Træholt, Chresten

2014-01-01

The paper presents results of a study on the dynamic response of Electric Vehicle’s (EV) when participating in frequency control of an islanded system. The following cases were considered: when there is no EV performing frequency control, when the EV participates in primary frequency control...... and when the EV participates in both primary and secondary frequency control. Different parameters are tested in various combinations, and their influence on frequency deviation as well as power and energy provided by the EV with vehicle-to-grid (V2G) capability is shown....

Integrated Locomotor Function Tests for Countermeasure Evaluation

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Bloomberg, J. J.; Mulavara, A. P.; Peters, B. T.; Cohen, H. S.; Landsness, E. C.; Black, F. O.

2005-01-01

Following spaceflight crewmembers experience locomotor dysfunction due to inflight adaptive alterations in sensorimotor function. Countermeasures designed to mitigate these postflight gait alterations need to be assessed with a new generation of tests that evaluate the interaction of various sensorimotor sub-systems central to locomotor control. The goal of the present study was to develop new functional tests of locomotor control that could be used to test the efficacy of countermeasures. These tests were designed to simultaneously examine the function of multiple sensorimotor systems underlying the control of locomotion and be operationally relevant to the astronaut population. Traditionally, gaze stabilization has been studied almost exclusively in seated subjects performing target acquisition tasks requiring only the involvement of coordinated eye-head movements. However, activities like walking involve full-body movement and require coordination between lower limbs and the eye-head-trunk complex to achieve stabilized gaze during locomotion. Therefore the first goal of this study was to determine how the multiple, interdependent, full-body sensorimotor gaze stabilization subsystems are functionally coordinated during locomotion. In an earlier study we investigated how alteration in gaze tasking changes full-body locomotor control strategies. Subjects walked on a treadmill and either focused on a central point target or read numeral characters. We measured: temporal parameters of gait, full body sagittal plane segmental kinematics of the head, trunk, thigh, shank and foot, accelerations along the vertical axis at the head and the shank, and the vertical forces acting on the support surface. In comparison to the point target fixation condition, the results of the number reading task showed that compensatory head pitch movements increased, peak head acceleration was reduced and knee flexion at heel-strike was increased. In a more recent study we investigated the

Classification of rhythmic locomotor patterns in electromyographic signals using fuzzy sets

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Thrasher Timothy A

2011-12-01

Full Text Available Abstract Background Locomotor control is accomplished by a complex integration of neural mechanisms including a central pattern generator, spinal reflexes and supraspinal control centres. Patterns of muscle activation during walking exhibit an underlying structure in which groups of muscles seem to activate in united bursts. Presented here is a statistical approach for analyzing Surface Electromyography (SEMG data with the goal of classifying rhythmic "burst" patterns that are consistent with a central pattern generator model of locomotor control. Methods A fuzzy model of rhythmic locomotor patterns was optimized and evaluated using SEMG data from a convenience sample of four able-bodied individuals. As well, two subjects with pathological gait participated: one with Parkinson's Disease, and one with incomplete spinal cord injury. Subjects walked overground and on a treadmill while SEMG was recorded from major muscles of the lower extremities. The model was fit to half of the recorded data using non-linear optimization and validated against the other half of the data. The coefficient of determination, R2, was used to interpret the model's goodness of fit. Results Using four fuzzy burst patterns, the model was able to explain approximately 70-83% of the variance in muscle activation during treadmill gait and 74% during overground gait. When five burst functions were used, one function was found to be redundant. The model explained 81-83% of the variance in the Parkinsonian gait, and only 46-59% of the variance in spinal cord injured gait. Conclusions The analytical approach proposed in this article is a novel way to interpret multichannel SEMG signals by reducing the data into basic rhythmic patterns. This can help us better understand the role of rhythmic patterns in locomotor control.

Mephedrone interactions with cocaine: prior exposure to the 'bath salt' constituent enhances cocaine-induced locomotor activation in rats.

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Gregg, Ryan A; Tallarida, Christopher S; Reitz, Allen B; Rawls, Scott M

2013-12-01

Concurrent use of mephedrone (4-methylmethcathinone; MEPH) and established drugs of abuse is now commonplace, but knowledge about interactions between these drugs is sparse. The present study was designed to test the hypothesis that prior MEPH exposure enhances the locomotor-stimulant effects of cocaine and methamphetamine (METH). For cocaine experiments, rats pretreated with saline, cocaine (15 mg/kg), or MEPH (15 mg/kg) for 5 days were injected with cocaine after 10 days of drug absence. For METH experiments, rats pretreated with saline, METH (2 mg/kg), or MEPH (15 mg/kg) were injected with METH after 10 days of drug absence. Cocaine challenge produced greater locomotor activity after pretreatment with cocaine or MEPH than after pretreatment with saline. METH challenge produced greater locomotor activity after METH pretreatment than after saline pretreatment; however, locomotor activity in rats pretreated with MEPH or saline and then challenged with METH was not significantly different. The locomotor response to MEPH (15 mg/kg) was not significantly affected by pretreatment with cocaine (15 mg/kg) or METH (0.5, 2 mg/kg). The present demonstration that cocaine-induced locomotor activation is enhanced by prior MEPH exposure suggests that MEPH cross-sensitizes to cocaine and increases cocaine efficacy. Interestingly, MEPH cross-sensitization was not bidirectional and did not extend to METH, suggesting that the phenomenon is sensitive to specific psychostimulants.

Slow Versus Fast Robot-Assisted Locomotor Training After Severe Stroke: A Randomized Controlled Trial.

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Rodrigues, Thais Amanda; Goroso, Daniel Gustavo; Westgate, Philip M; Carrico, Cheryl; Batistella, Linamara R; Sawaki, Lumy

2017-10-01

Robot-assisted locomotor training on a bodyweight-supported treadmill is a rehabilitation intervention that compels repetitive practice of gait movements. Standard treadmill speed may elicit rhythmic movements generated primarily by spinal circuits. Slower-than-standard treadmill speed may elicit discrete movements, which are more complex than rhythmic movements and involve cortical areas. Compare effects of fast (i.e., rhythmic) versus slow (i.e., discrete) robot-assisted locomotor training on a bodyweight-supported treadmill in subjects with chronic, severe gait deficit after stroke. Subjects (N = 18) were randomized to receive 30 sessions (5 d/wk) of either fast or slow robot-assisted locomotor training on a bodyweight-supported treadmill in an inpatient setting. Functional ambulation category, time up and go, 6-min walk test, 10-m walk test, Berg Balance Scale, and Fugl-Meyer Assessment were administered at baseline and postintervention. The slow group had statistically significant improvement on functional ambulation category (first quartile-third quartile, P = 0.004), 6-min walk test (95% confidence interval [CI] = 1.8 to 49.0, P = 0.040), Berg Balance Scale (95% CI = 7.4 to 14.8, P locomotor training on a bodyweight-supported treadmill after severe stroke, slow training targeting discrete movement may yield greater benefit than fast training.

Usability evaluation of a locomotor therapy device considering different strategies

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Langthaler Sonja

2016-09-01

Full Text Available Usability of medical devices is one of the main determining factors in preventing use errors in treatment and strongly correlates to patient safety and quality of treatment. This thesis demonstrates the usability testing and evaluation of a prototype for locomotor therapy of infants. Therefore, based on the normative requirements of the EN 62366, a concept combined of evaluation procedures and assessing methods was created to enable extensive testing and analysis of the different aspects of usability. On the basis of gathered information weak points were identified and appropriate measures were presented to increase the usability and operating safety of the locomotor prototype. The overall outcome showed an usability value of 77.4% and an evaluation score of 6.99, which can be interpreted as “satisfactory”.

Locomotion dynamics of hunting in wild cheetahs.

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Wilson, A M; Lowe, J C; Roskilly, K; Hudson, P E; Golabek, K A; McNutt, J W

2013-06-13

Although the cheetah is recognised as the fastest land animal, little is known about other aspects of its notable athleticism, particularly when hunting in the wild. Here we describe and use a new tracking collar of our own design, containing a combination of Global Positioning System (GPS) and inertial measurement units, to capture the locomotor dynamics and outcome of 367 predominantly hunting runs of five wild cheetahs in Botswana. A remarkable top speed of 25.9 m s(-1) (58 m.p.h. or 93 km h(-1)) was recorded, but most cheetah hunts involved only moderate speeds. We recorded some of the highest measured values for lateral and forward acceleration, deceleration and body-mass-specific power for any terrestrial mammal. To our knowledge, this is the first detailed locomotor information on the hunting dynamics of a large cursorial predator in its natural habitat.

[Disorders of locomotor system and effectiveness of physiotherapy in coal miners].

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Bilski, Bartosz; Bednarek, Agata

2003-01-01

The aim of the survey was to analyze the efficacy of physiotherapy applied in coal miners as well as to assess their locomotor system load and the effects of working conditions in mines. The questionnaire survey covered a group of 51 miners, aged 28-76 years (mean, 54 years), undergoing physiotherapeutic procedures in the mine out-patient clinic during the first quarter of 2003. The survey revealed that lumbosacral disorders were the most frequent locomotor system complaints reported by miners, especially those who work in a bending down position. According to the clinical data, spondylosis and allied disorders were the main reasons for pain in this part of the body. Having analyzed the relationship between age and occurrence of back pains, the majority of complaints were found in the 46-55 age group (two complaints per one respondent). The analysis of the association between back pains and duration of employment revealed that the complaints for the locomotor system occurred already after a five-year employment. The survey showed that the application of physiotherapeutic procedures diminished the back pain in the study group by 2.83 on average on the 0-10 scale. It was also found that magnetotherapy proved to be the most effective method in treating the spinal degenerative changes.

Improved gait after repetitive locomotor training in children with cerebral palsy.

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Smania, Nicola; Bonetti, Paola; Gandolfi, Marialuisa; Cosentino, Alessandro; Waldner, Andreas; Hesse, Stefan; Werner, Cordula; Bisoffi, Giulia; Geroin, Christian; Munari, Daniele

2011-02-01

The aim of this study was to evaluate the effectiveness of repetitive locomotor training with an electromechanical gait trainer in children with cerebral palsy. In this randomized controlled trial, 18 ambulatory children with diplegic or tetraplegic cerebral palsy were randomly assigned to an experimental group or a control group. The experimental group received 30 mins of repetitive locomotor training with an applied technology (Gait Trainer GT I) plus 10 mins of passive joint mobilization and stretching exercises. The control group received 40 mins of conventional physiotherapy. Each subject underwent a total of 10 treatment sessions over a 2-wk period. Performance on the 10-m walk test, 6-min walk test, WeeFIM scale, and gait analysis was evaluated by a blinded rater before and after treatment and at 1-mo follow-up. The experimental group showed significant posttreatment improvement on the 10-m walk test, 6-min walk test, hip kinematics, gait speed, and step length, all of which were maintained at the 1-mo follow-up assessment. No significant changes in performance parameters were observed in the control group. Repetitive locomotor training with an electromechanical gait trainer may improve gait velocity, endurance, spatiotemporal, and kinematic gait parameters in patients with cerebral palsy.

Experiential knowledge of expert coaches can help identify informational constraints on performance of dynamic interceptive actions.

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Greenwood, Daniel; Davids, Keith; Renshaw, Ian

2014-01-01

Coordination of dynamic interceptive movements is predicated on cyclical relations between an individual's actions and information sources from the performance environment. To identify dynamic informational constraints, which are interwoven with individual and task constraints, coaches' experiential knowledge provides a complementary source to support empirical understanding of performance in sport. In this study, 15 expert coaches from 3 sports (track and field, gymnastics and cricket) participated in a semi-structured interview process to identify potential informational constraints which they perceived to regulate action during run-up performance. Expert coaches' experiential knowledge revealed multiple information sources which may constrain performance adaptations in such locomotor pointing tasks. In addition to the locomotor pointing target, coaches' knowledge highlighted two other key informational constraints: vertical reference points located near the locomotor pointing target and a check mark located prior to the locomotor pointing target. This study highlights opportunities for broadening the understanding of perception and action coupling processes, and the identified information sources warrant further empirical investigation as potential constraints on athletic performance. Integration of experiential knowledge of expert coaches with theoretically driven empirical knowledge represents a promising avenue to drive future applied science research and pedagogical practice.

Cocaine-induced locomotor activity in rats selectively bred for low and high voluntary running behavior.

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Brown, Jacob D; Green, Caroline L; Arthur, Ian M; Booth, Frank W; Miller, Dennis K

2015-02-01

The rewarding effects of physical activity and abused drugs are caused by stimulation of similar brain pathways. Low (LVR) and high (HVR) voluntary running lines were developed by selectively breeding Wistar rats on running distance performance on postnatal days 28-34. We hypothesized that LVR rats would be more sensitive to the locomotor-activating effects of cocaine than HVR rats due to their lower motivation for wheel running. We investigated how selection for LVR or HVR behavior affects inherited activity responses: (a) open field activity levels, (b) habituation to an open field environment, and (c) the locomotor response to cocaine. Open field activity was measured for 80 min on three successive days (days 1-3). Data from the first 20 min were analyzed to determine novelty-induced locomotor activity (day 1) and the habituation to the environment (days 1-3). On day 3, rats were acclimated to the chamber for 20 min and then received saline or cocaine (10, 20, or 30 mg/kg) injection. Dopamine transporter (DAT) protein in the nucleus accumbens was measured via Western blot. Selecting for low and high voluntary running behavior co-selects for differences in inherent (HVR > LVR) and cocaine-induced (LVR > HVR) locomotor activity levels. The differences in the selected behavioral measures do not appear to correlate with DAT protein levels. LVR and HVR rats are an intriguing physical activity model for studying the interactions between genes related to the motivation to run, to use drugs of abuse, and to exhibit locomotor activity.

Evidence for a role of orexin/hypocretin system in vestibular lesion-induced locomotor abnormalities in rats

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Leilei Pan

2016-07-01

Full Text Available Vestibular damage can induce locomotor abnormalities in both animals and humans. Rodents with bilateral vestibular loss showed vestibular deficits syndrome such as circling, opisthotonus as well as locomotor and exploratory hyperactivity. Previous studies have investigated the changes in the dopamine system after vestibular loss, but the results are inconsistent and inconclusive. Numerous evidences indicate that the orexin system is implicated in central motor control. We hypothesized that orexin may be potentially involved in vestibular loss-induced motor disorders. In this study, we examined the effects of arsanilate- or 3, 3′-iminodipropionitrile (IDPN-induced vestibular lesion (AVL or IVL on the orexin-A (OXA labeling in rat hypothalamus using immunohistochemistry. The vestibular lesion-induced locomotor abnormalities were recorded and verified using a histamine H4 receptor antagonist JNJ7777120 (20 mg/kg, i.p.. The effects of the orexin receptor type 1 antagonist SB334867 (16 μg, i.c.v. on these behavior responses were also investigated. At 72 h post-AVL and IVL, animals exhibited vestibular deficit syndrome and locomotor hyperactivity in the home cages. These responses were significantly alleviated by JNJ7777120 which also eliminated AVL-induced increases in exploratory behavior in an open field. The numbers of OXA-labeled neurons in the hypothalamus were significantly increased in the AVL animals at 72 h post-AVL and in the IVL animals at 24, 48 and 72 h post-IVL. SB334867 significantly attenuated the vestibular deficit syndrome and locomotor hyperactivity at 72 h post-AVL and IVL. It also decreased exploratory behavior in the AVL animals. These results suggested that the alteration of OXA expression might contribute to locomotor abnormalities after acute vestibular lesion. The orexin receptors might be the potential therapeutic targets for vestibular disorders.

Effects of scallop shell extract on scopolamine-induced memory impairment and MK801-induced locomotor activity.

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Hasegawa, Yasushi; Inoue, Tatsuro; Kawaminami, Satoshi; Fujita, Miho

2016-07-01

To evaluate the neuroprotective effects of the organic components of scallop shells (scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibenzo (a,d) cyclohepten-5,10-imine (MK801). Effect of the scallop shell extract on memory impairment and locomotor activity was investigated using the Y-maze test, the Morris water maze test, and the open field test. Scallop shell extract significantly reduced scopolamine-induced short-term memory impairment and partially reduced scopolamine-induced spatial memory impairment in the Morris water maze test. Scallop shell extract suppressed scopolamine-induced elevation of acetylcholine esterase activity in the cerebral cortex. Treatment with scallop shell extract reversed the increase in locomotor activity induced by scopolamine. Scallop shell extract also suppressed the increase in locomotor activity induced by MK801. Our results provide initial evidence that scallop shell extract reduces scopolamine-induced memory impairment and suppresses MK-801-induced hyperlocomotion. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

Effects of sex pheromones and sexual maturation on locomotor activity in female sea lamprey (Petromyzon marinus)

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Walaszczyk, Erin J.; Johnson, Nicholas S.; Steibel, Juan Pedro; Li, Weiming

2013-01-01

Synchronization of male and female locomotor rhythmicity can play a vital role in ensuring reproductive success. Several physiological and environmental factors alter these locomotor rhythms. As sea lamprey, Petromyzon marinus, progress through their life cycle, their locomotor activity rhythm changes multiple times. The goal of this study was to elucidate the activity patterns of adult female sea lamprey during the sexual maturation process and discern the interactions of these patterns with exposure to male pheromones. During these stages, preovulated and ovulated adult females are exposed to sex pheromone compounds, which are released by spermiated males and attract ovulated females to the nest for spawning. The locomotor behavior of adult females was monitored in a natural stream with a passive integrated tag responder system as they matured, and they were exposed to a sex pheromone treatment (spermiated male washings) or a control (prespermiated male washings). Results showed that, dependent on the hour of day, male sex pheromone compounds reduce total activity (p reproductive synchrony of mature adults, thus increasing reproductive success in this species.

Glutamatergic mechanisms for speed control and network operation in the rodent locomotor CPG

DEFF Research Database (Denmark)

Talpalar, Adolfo E.; Kiehn, Ole

2010-01-01

in mammals have produced conflicting results regarding the necessity and role of the different ionotropic glutamate receptors (GluRs) in the CPG function. Here, we use electrophysiological and pharmacological techniques in the in vitro neonatal mouse lumbar spinal cord to investigate the role of a broad...... mechanisms acting at various network levels. AMPA and kainate receptors are necessary for generating the highest locomotor frequencies. For coordination, NMDARs are more important than non-NMDARs for conveying the rhythmic signal from the network to the motor neurons during long-lasting and steady locomotor...

The effects of sex-ratio and density on locomotor activity in the house fly, Musca domestica

DEFF Research Database (Denmark)

Bahrndorff, Simon; Kjaersgaard, Anders; Pertoldi, Cino

2012-01-01

Although locomotor activity is involved in almost all behavioral traits, there is a lack of knowledge on what factors affect it. This study examined the effects of sex-ratio and density on the circadian rhythm of locomotor activity of adult Musca domestica L. (Diptera: Muscidae) using an infra......-red light system. Sex-ratio significantly affected locomotor activity, increasing with the percentage of males in the vials. In accordance with other studies, males were more active than females, but the circadian rhythm of the two sexes was not constant over time and changed during the light period...... of the behavioral interactions between houseflies and highlight the importance of these factors when designing behavioral experiments using M. domestica....

Drosophila Clock Is Required in Brain Pacemaker Neurons to Prevent Premature Locomotor Aging Independently of Its Circadian Function.

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Alexandra Vaccaro

2017-01-01

Full Text Available Circadian clocks control many self-sustained rhythms in physiology and behavior with approximately 24-hour periodicity. In many organisms, oxidative stress and aging negatively impact the circadian system and sleep. Conversely, loss of the clock decreases resistance to oxidative stress, and may reduce lifespan and speed up brain aging and neurodegeneration. Here we examined the effects of clock disruptions on locomotor aging and longevity in Drosophila. We found that lifespan was similarly reduced in three arrhythmic mutants (ClkAR, cyc0 and tim0 and in wild-type flies under constant light, which stops the clock. In contrast, ClkAR mutants showed significantly faster age-related locomotor deficits (as monitored by startle-induced climbing than cyc0 and tim0, or than control flies under constant light. Reactive oxygen species accumulated more with age in ClkAR mutant brains, but this did not appear to contribute to the accelerated locomotor decline of the mutant. Clk, but not Cyc, inactivation by RNA interference in the pigment-dispersing factor (PDF-expressing central pacemaker neurons led to similar loss of climbing performance as ClkAR. Conversely, restoring Clk function in these cells was sufficient to rescue the ClkAR locomotor phenotype, independently of behavioral rhythmicity. Accelerated locomotor decline of the ClkAR mutant required expression of the PDF receptor and correlated to an apparent loss of dopaminergic neurons in the posterior protocerebral lateral 1 (PPL1 clusters. This neuronal loss was rescued when the ClkAR mutation was placed in an apoptosis-deficient background. Impairing dopamine synthesis in a single pair of PPL1 neurons that innervate the mushroom bodies accelerated locomotor decline in otherwise wild-type flies. Our results therefore reveal a novel circadian-independent requirement for Clk in brain circadian neurons to maintain a subset of dopaminergic cells and avoid premature locomotor aging in Drosophila.

Age-Related Changes in Locomotor Performance Reveal a Similar Pattern for Caenorhabditis elegans, Mus domesticus, Canis familiaris, Equus caballus, and Homo sapiens.

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Marck, Adrien; Berthelot, Geoffroy; Foulonneau, Vincent; Marc, Andy; Antero-Jacquemin, Juliana; Noirez, Philippe; Bronikowski, Anne M; Morgan, Theodore J; Garland, Theodore; Carter, Patrick A; Hersen, Pascal; Di Meglio, Jean-Marc; Toussaint, Jean-François

2017-04-01

Locomotion is one of the major physiological functions for most animals. Previous studies have described aging mechanisms linked to locomotor performance among different species. However, the precise dynamics of these age-related changes, and their interactions with development and senescence, are largely unknown. Here, we use the same conceptual framework to describe locomotor performances in Caenorhabditis elegans, Mus domesticus, Canis familiaris, Equus caballus, and Homo sapiens. We show that locomotion is a consistent biomarker of age-related changes, with an asymmetrical pattern throughout life, regardless of the type of effort or its duration. However, there is variation (i) among species for the same mode of locomotion, (ii) within species for different modes of locomotion, and (iii) among individuals of the same species for the same mode of locomotion. Age-related patterns are modulated by genetic (such as selective breeding) as well as environmental conditions (such as temperature). However, in all cases, the intersection of the rising developmental phase and the declining senescent phase reveals neither a sharp transition nor a plateau, but a smooth transition, emphasizing a crucial moment: the age at peak performance. This transition may define a specific target for future investigations on the dynamics of such biological interactions. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Locomotor therapy with extended-release crystalline glucocorticoids

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Vladimir Vasilyevich Badokin

2013-01-01

Full Text Available Topical glucocorticoid (GC therapy for locomotor diseases is an extremely important component of a comprehensive program to treat inflammatory and, to a lesser extent, degenerative diseases. It reduces the time of hospitalization by 5—10 days in this category of patients, has a prompt and potent anti-inflammatory effect, and shows predictable efficiency. This therapy shows good tolerability and high safety and prevents serious adverse reactions to GC treatment.

Functional reorganization of the locomotor network in Parkinson patients with freezing of gait.

Directory of Open Access Journals (Sweden)

Brett W Fling

Full Text Available Freezing of gait (FoG is a transient inability to initiate or maintain stepping that often accompanies advanced Parkinson's disease (PD and significantly impairs mobility. The current study uses a multimodal neuroimaging approach to assess differences in the functional and structural locomotor neural network in PD patients with and without FoG and relates these findings to measures of FoG severity. Twenty-six PD patients and fifteen age-matched controls underwent resting-state functional magnetic resonance imaging and diffusion tensor imaging along with self-reported and clinical assessments of FoG. After stringent movement correction, fifteen PD patients and fourteen control participants were available for analysis. We assessed functional connectivity strength between the supplementary motor area (SMA and the following locomotor hubs: 1 subthalamic nucleus (STN, 2 mesencephalic and 3 cerebellar locomotor region (MLR and CLR, respectively within each hemisphere. Additionally, we quantified structural connectivity strength between locomotor hubs and assessed relationships with metrics of FoG. FoG+ patients showed greater functional connectivity between the SMA and bilateral MLR and between the SMA and left CLR compared to both FoG- and controls. Importantly, greater functional connectivity between the SMA and MLR was positively correlated with i clinical, ii self-reported and iii objective ratings of freezing severity in FoG+, potentially reflecting a maladaptive neural compensation. The current findings demonstrate a re-organization of functional communication within the locomotor network in FoG+ patients whereby the higher-order motor cortex (SMA responsible for gait initiation communicates with the MLR and CLR to a greater extent than in FoG- patients and controls. The observed pattern of altered connectivity in FoG+ may indicate a failed attempt by the CNS to compensate for the loss of connectivity between the STN and SMA and may reflect a

Sound stabilizes locomotor-respiratory coupling and reduces energy cost.

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Charles P Hoffmann

Full Text Available A natural synchronization between locomotor and respiratory systems is known to exist for various species and various forms of locomotion. This Locomotor-Respiratory Coupling (LRC is fundamental for the energy transfer between the two subsystems during long duration exercise and originates from mechanical and neurological interactions. Different methodologies have been used to compute LRC, giving rise to various and often diverging results in terms of synchronization, (de-stabilization via information, and associated energy cost. In this article, the theory of nonlinear-coupled oscillators was adopted to characterize LRC, through the model of the sine circle map, and tested it in the context of cycling. Our specific focus was the sound-induced stabilization of LRC and its associated change in energy consumption. In our experimental study, participants were instructed during a cycling exercise to synchronize either their respiration or their pedaling rate with an external auditory stimulus whose rhythm corresponded to their individual preferential breathing or cycling frequencies. Results showed a significant reduction in energy expenditure with auditory stimulation, accompanied by a stabilization of LRC. The sound-induced effect was asymmetrical, with a better stabilizing influence of the metronome on the locomotor system than on the respiratory system. A modification of the respiratory frequency was indeed observed when participants cycled in synchrony with the tone, leading to a transition toward more stable frequency ratios as predicted by the sine circle map. In addition to the classical mechanical and neurological origins of LRC, here we demonstrated using the sine circle map model that information plays an important modulatory role of the synchronization, and has global energetic consequences.

Activity of Renshaw cells during locomotor-like rhythmic activity in the isolated spinal cord of neonatal mice

DEFF Research Database (Denmark)

Nishimaru, Hiroshi; Restrepo, Carlos E.; Kiehn, Ole

2006-01-01

% of the recorded RCs fired in-phase with the ipsilateral L2 flexor-related rhythm, whereas the rest fired in the extensor phase. Each population of RCs fired throughout the corresponding locomotor phase. All RCs received both excitatory and inhibitory synaptic inputs during the locomotor-like rhythmic activity...

Applying a multi-replication framework to support dynamic situation assessment and predictive capabilities

Science.gov (United States)

Lammers, Craig; McGraw, Robert M.; Steinman, Jeffrey S.

2005-05-01

Technological advances and emerging threats reduce the time between target detection and action to an order of a few minutes. To effectively assist with the decision-making process, C4I decision support tools must quickly and dynamically predict and assess alternative Courses Of Action (COAs) to assist Commanders in anticipating potential outcomes. These capabilities can be provided through the faster-than-real-time predictive simulation of plans that are continuously re-calibrating with the real-time picture. This capability allows decision-makers to assess the effects of re-tasking opportunities, providing the decision-maker with tremendous freedom to make time-critical, mid-course decisions. This paper presents an overview and demonstrates the use of a software infrastructure that supports DSAP capabilities. These DSAP capabilities are demonstrated through the use of a Multi-Replication Framework that supports (1) predictivie simulations using JSAF (Joint Semi-Automated Forces); (2) real-time simulation, also using JSAF, as a state estimation mechanism; and, (3) real-time C4I data updates through TBMCS (Theater Battle Management Core Systems). This infrastructure allows multiple replications of a simulation to be executed simultaneously over a grid faster-than-real-time, calibrated with live data feeds. A cost evaluator mechanism analyzes potential outcomes and prunes simulations that diverge from the real-time picture. In particular, this paper primarily serves to walk a user through the process for using the Multi-Replication Framework providing an enhanced decision aid.

Dynamic Analytical Capability to Better Understand and Anticipate Extremist Shifts Within Populations under Authoritarian Regimes.

Energy Technology Data Exchange (ETDEWEB)

Bernard, Michael Lewis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-11-01

The purpose of this work is to create a generalizable data- and theory-supported capability to better understand and anticipate (with quantifiable uncertainty): 1) how the dynamics of allegiance formations between various groups and society are impacted by active conflict and by third-party interventions and 2) how/why extremist allegiances co-evolve over time due to changing geopolitical, sociocultural, and military conditions.

Comparison of locomotor behaviour between white-headed langurs Trachypithecus leucocephalus and François’ langurs T. françoisi in Fusui, China

OpenAIRE

Jinrong XIONG; Shihua GONG; Chenggang QIU; Zhaoyuan LI

2009-01-01

We studied the locomotor behaviour of white-headed langurs Trachypithecus leucocephalus and François’ langurs T.françoisi to test two hypotheses: (1) these monkeys have evolved locomotor ability to support their activities on limestone hills, and (2) François’ langurs have evolved more diverse locomotor skills than white-headed langurs. Data were collected from 1996–1998 and in 2005 in Fusui Nature Reserve, Guangxi, and showed that the two species had similar locomotor types, but François’ l...

Efffects of vigabatrin on spontaneous locomotor activity of rats

NARCIS (Netherlands)

Bouwman, B.M.; Rijn, C.M. van; Willems-van Bree, P.C.M.; Coenen, A.M.L.

2003-01-01

Effects of vigibatrin (saline, 125, 250, or 500 mg/kg i.p.) on spontaneous locomotor activity in Wistar rats were investigated. There was a dose dependent decrease in amount of locomotion for doses up to 250 mg/kg. This decrease was measurable 2-4 hours after injection and still became more

Adaptation of a ladder beam walking task to assess locomotor recovery in mice following spinal cord injury

Science.gov (United States)

Cummings, Brian J.; Engesser-Cesar, Christie; Anderson, Aileen J.

2007-01-01

Locomotor impairments after spinal cord injury (SCI) are often assessed using open-field rating scales. These tasks have the advantage of spanning the range from complete paralysis to normal walking; however, they lack sensitivity at specific levels of recovery. Additionally, most supplemental assessments were developed in rats, not mice. For example, the horizontal ladder beam has been used to measure recovery in the rat after SCI. This parametric task results in a videotaped archival record of the event, is easily administered, and is unambiguously scored. Although a ladder beam apparatus for mice is available, its use in the assessment of recovery in SCI mice is rare, possibly because normative data for uninjured mice and the type of step misplacements injured mice exhibit is lacking. We report the development of a modified ladder beam instrument and scoring system to measure hindlimb recovery in vertebral T9 contusion spinal cord injured mice. The mouse ladder beam allows for the use of standard parametric statistical tests to assess locomotor recovery. Ladder beam performance is consistent across four strains of mice, there are no sex differences, and inter-rater reliability between observers is high. The ladder beam score is proportional to injury severity and can be used to easily separate mice capable of weight-supported stance up to mice with consistent forelimb to hindlimb coordination. Critically, horizontal ladder beam testing discriminates between mice that score identically in terms of stepping frequency in open-field testing. PMID:17197044

Adaptation of a ladder beam walking task to assess locomotor recovery in mice following spinal cord injury.

Science.gov (United States)

Cummings, Brian J; Engesser-Cesar, Christie; Cadena, Gilbert; Anderson, Aileen J

2007-02-27

Locomotor impairments after spinal cord injury (SCI) are often assessed using open-field rating scales. These tasks have the advantage of spanning the range from complete paralysis to normal walking; however, they lack sensitivity at specific levels of recovery. Additionally, most supplemental assessments were developed in rats, not mice. For example, the horizontal ladder beam has been used to measure recovery in the rat after SCI. This parametric task results in a videotaped archival record of the event, is easily administered, and is unambiguously scored. Although a ladder beam apparatus for mice is available, its use in the assessment of recovery in SCI mice is rare, possibly because normative data for uninjured mice and the type of step misplacements injured mice exhibit is lacking. We report the development of a modified ladder beam instrument and scoring system to measure hindlimb recovery in vertebral T9 contusion spinal cord injured mice. The mouse ladder beam allows for the use of standard parametric statistical tests to assess locomotor recovery. Ladder beam performance is consistent across four strains of mice, there are no sex differences, and inter-rater reliability between observers is high. The ladder beam score is proportional to injury severity and can be used to easily separate mice capable of weight-supported stance up to mice with consistent forelimb to hindlimb coordination. Critically, horizontal ladder beam testing discriminates between mice that score identically in terms of stepping frequency in open-field testing.

Effect of temporal organization of the visuo-locomotor coupling on the predictive steering

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Yves Philippe Rybarczyk

2012-07-01

Full Text Available Studies on the direction of a driver’s gaze while taking a bend show that the individual looks towards the tangent-point of the inside curve. Mathematically, the direction of this point in relation to the car enables the driver to predict the curvature of the road. In the same way, when a person walking in the street makes a turn at the corner, his/her gaze anticipates the rotation of the body. A current explanation for the visuo-motor anticipation over the locomotion would be that the brain, involved in a steering behaviour, executes an internal model of the trajectory that anticipates the path completion, and not the contrary. This paper proposes to test this hypothesis by studying the effect of an artificial manipulation of the visuo-locomotor coupling on the trajectory prediction. In this experiment, subjects remotely control a mobile robot with a pan-tilt camera. This experimental paradigm is chosen to easily and precisely manipulate the temporal organization of the visuo-locomotor coupling. Results show that only the visuo-locomotor coupling organized from the visual sensor to the locomotor organs enables i a significant smoothness of the trajectory and ii a velocity-curvature relationship that follows the 2/3 Power Law. These findings are consistent with the theory of an anticipatory construction of an internal model of the trajectory. This mental representation used by the brain as a forward prediction of the path formation seems conditioned by the motor program. The overall results are discussed in terms of the sensorimotor scheme bases of the predictive coding.

A cable-driven locomotor training system for restoration of gait in human SCI.

Science.gov (United States)

Wu, Ming; Hornby, T George; Landry, Jill M; Roth, Heidi; Schmit, Brian D

2011-02-01

A novel cable-driven robotic locomotor training system was developed to provide compliant assistance/resistance forces to the legs during treadmill training in patients with incomplete spinal cord injury (SCI). Eleven subjects with incomplete SCI were recruited to participate in two experiments to test the feasibility of the robotic gait training system. Specifically, 10 subjects participated in one experimental session to test the characteristics of the robotic gait training system and one subject participated in repeated testing sessions over 8 weeks with the robotic device to test improvements in locomotor function. Limb kinematics were recorded in one experiment to evaluate the system characteristics of the cable-driven locomotor trainer and the overground gait speed and 6 min walking distance were evaluated at pre, 4 and 8 weeks post treadmill training of a single subject as well. The results indicated that the cable driven robotic gait training system improved the kinematic performance of the leg during treadmill walking and had no significant impact on the variability of lower leg trajectory, suggesting a high backdrivability of the cable system. In addition, results from a patient with incomplete SCI indicated that prolonged robotic gait training using the cable robot improved overground gait speed. Results from this study suggested that a cable driven robotic gait training system is effective in improving leg kinematic performance, yet allows variability of gait kinematics. Thus, it seems feasible to improve the locomotor function in human SCI using this cable driven robotic system, warranting testing with a larger group of patients. Copyright © 2010 Elsevier B.V. All rights reserved.

Anxiolytics may promote locomotor function recovery in spinal cord injury patients

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Pierre A Guertin

2008-09-01

Full Text Available Pierre A GuertinNeuroscience Unit, Laval University Medical Center (CHUL, Quebec City, CanadaAbstract: Recent findings in animal models of paraplegia suggest that specific nonbenzodiazepine anxiolytics may temporarily restore locomotor functions after spinal cord injury (SCI. Experiments using in vitro models have revealed, indeed, that selective serotonin receptor (5-HTR ligands such as 5-HTR1A agonists, known as relatively safe anxiolytics, can acutely elicit episodes of rhythmic neuronal activity refered to as fictive locomotion in isolated spinal cord preparations. Along the same line, in vivo studies have recently shown that this subclass of anxiolytics can induce, shortly after systemic administration (eg, orally or subcutaneously, some locomotor-like hindlimb movements during 45–60 minutes in completely spinal cord-transected (Tx rodents. Using ‘knock-out’ mice (eg, 5-HTR7-/- and selective antagonists, it has been clearly established that both 5-HTR1A and 5-HTR7 were critically involved in mediating the pro-locomotor effects induced by 8-OH-DPAT (typically referred to as a 5-HTR1A agonist in Tx animals. Taken together, these in vitro and in vivo data strongly support the idea that 5-HTR1A agonists may eventually become constitutive elements of a novel first-in-class combinatorial treatment aimed at periodically inducing short episodes of treadmill stepping in SCI patients.Keywords: 5-HT agonists, anxiolytics, locomotion, SCI

Olanzapine affects locomotor activity and meal size in male rats

NARCIS (Netherlands)

van der Zwaal, Esther M.; Luijendijk, Mieneke C. M.; Evers, Simon S.; la Fleur, Susanne E.; Adan, Roger A. H.

2010-01-01

Olanzapine is an antipsychotic drug that frequently induces weight gain accompanied by increased fat deposition as a side effect. To investigate how olanzapine affects different aspects of energy balance, we used male rats to determine effects on meal patterns, food preference, locomotor activity

Effect of physical exercise prelabyrinthectomy on locomotor balance compensation in the squirrel monkey

Science.gov (United States)

Igarashi, M.; Ohashi, K.; Yoshihara, T.; MacDonald, S.

1989-01-01

This study examines the effectiveness of physical exercise, during a prepathology state, on locomotor balance compensation after subsequent unilateral labyrinthectomy in squirrel monkeys. An experimental group underwent 3 hr. of daily running exercise on a treadmill for 3 mo. prior to the surgery, whereas a control group was not exercised. Postoperatively, the locomotor balance function of both groups was tested for 3 mo. There was no significant difference in gait deviation counts in the acute phase of compensation. However, in the chronic compensation maintenance phase, the number of gait deviation counts was fewer in the exercise group, which showed significantly better performance stability.

Distributed plasticity of locomotor pattern generators in spinal cord injured patients.

Science.gov (United States)

Grasso, Renato; Ivanenko, Yuri P; Zago, Myrka; Molinari, Marco; Scivoletto, Giorgio; Castellano, Vincenzo; Macellari, Velio; Lacquaniti, Francesco

2004-05-01

Recent progress with spinal cord injured (SCI) patients indicates that with training they can recover some locomotor ability. Here we addressed the question of whether locomotor responses developed with training depend on re-activation of the normal motor patterns or whether they depend on learning new motor patterns. To this end we recorded detailed kinematic and EMG data in SCI patients trained to step on a treadmill with body-weight support (BWST), and in healthy subjects. We found that all patients could be trained to step with BWST in the laboratory conditions, but they used new coordinative strategies. Patients with more severe lesions used their arms and body to assist the leg movements via the biomechanical coupling of limb and body segments. In all patients, the phase-relationship of the angular motion of the different lower limb segments was very different from the control, as was the pattern of activity of most recorded muscles. Surprisingly, however, the new motor strategies were quite effective in generating foot motion that closely matched the normal in the laboratory conditions. With training, foot motion recovered the shape, the step-by-step reproducibility, and the two-thirds power relationship between curvature and velocity that characterize normal gait. We mapped the recorded patterns of muscle activity onto the approximate rostrocaudal location of motor neuron pools in the human spinal cord. The reconstructed spatiotemporal maps of motor neuron activity in SCI patients were quite different from those of healthy subjects. At the end of training, the locomotor network reorganized at both supralesional and sublesional levels, from the cervical to the sacral cord segments. We conclude that locomotor responses in SCI patients may not be subserved by changes localized to limited regions of the spinal cord, but may depend on a plastic redistribution of activity across most of the rostrocaudal extent of the spinal cord. Distributed plasticity underlies

Locomotor skills and balance strategies in adolescents idiopathic scoliosis.

Science.gov (United States)

Mallau, Sophie; Bollini, Gérard; Jouve, Jean-Luc; Assaiante, Christine

2007-01-01

Locomotor balance control assessment was performed to study the effect of idiopathic scoliosis on head-trunk coordination in 17 patients with adolescent idiopathic scoliosis (AIS) and 16 control subjects. The aim of this study was to explore the functional effects of structural spinal deformations like idiopathic scoliosis on the balance strategies used during locomotion. Up to now, the repercussion of the idiopathic scoliosis on head-trunk coordination and balance strategies during locomotion is relatively unknown. Seventeen patients with AIS (mean age 14 years 3 months, 10 degrees 30 degrees) and 16 control subjects (mean age 14 years 1 month) were tested during various locomotor tasks: walking on the ground, walking on a line, and walking on a beam. Balance control was examined in terms of rotation about the vertical axis (yaw) and on a frontal plane (roll). Kinematics of foot, pelvis, trunk, shoulder, and head rotations were measured with an automatic optical TV image processor in order to calculate angular dispersions and segmental stabilizations. Decreasing the walking speed is the main adaptive strategy used in response to balance problems in control subjects as well as patients with AIS. However, patients with AIS performed walking tasks more slowly than normal subjects (around 15%). Moreover, the pelvic stabilization is preserved, despite the structural changes affecting the spine. Lastly, the biomechanical defect resulting from idiopathic scoliosis mainly affects the yaw head stabilization during locomotion. Patients with AIS show substantial similarities with control subjects in adaptive strategies relative to locomotor velocity as well as balance control based on segmental stabilization. In contrast, the loss of the yaw head stabilization strategies, mainly based on the use of vestibular information, probably reflects the presence of vestibular deficits in the patients with AIS.

S-phenylpiracetam, a selective DAT inhibitor, reduces body weight gain without influencing locomotor activity.

Science.gov (United States)

Zvejniece, Liga; Svalbe, Baiba; Vavers, Edijs; Makrecka-Kuka, Marina; Makarova, Elina; Liepins, Vilnis; Kalvinsh, Ivars; Liepinsh, Edgars; Dambrova, Maija

2017-09-01

S-phenylpiracetam is an optical isomer of phenotropil, which is a clinically used nootropic drug that improves physical condition and cognition. Recently, it was shown that S-phenylpiracetam is a selective dopamine transporter (DAT) inhibitor that does not influence norepinephrine (NE) or serotonin (5-HT) receptors. The aim of the present study was to study the effects of S-phenylpiracetam treatment on body weight gain, blood glucose and leptin levels, and locomotor activity. Western diet (WD)-fed mice and obese Zucker rats were treated daily with peroral administration of S-phenylpiracetam for 8 and 12weeks, respectively. Weight gain and plasma metabolites reflecting glucose metabolism were measured. Locomotor activity was detected in an open-field test. S-phenylpiracetam treatment significantly decreased body weight gain and fat mass increase in the obese Zucker rats and in the WD-fed mice. In addition, S-phenylpiracetam reduced the plasma glucose and leptin concentration and lowered hyperglycemia in a glucose tolerance test in both the mice and the rats. S-phenylpiracetam did not influence locomotor activity in the obese Zucker rats or in the WD-fed mice. The results demonstrate that S-phenylpiracetam reduces body weight gain and improves adaptation to hyperglycemia without stimulating locomotor activity. Our findings suggest that selective DAT inhibitors, such as S-phenylpiracetam, could be potentially useful for treating obesity in patients with metabolic syndrome with fewer adverse health consequences compared to other anorectic agents. Copyright © 2017. Published by Elsevier Inc.

Selective brain lesions reduce morphine- and radiation-induced locomotor hyperactivity of the C57BL/6J mouse

International Nuclear Information System (INIS)

Mickley, G.A.; Stevens, K.E.; White, G.A.; Gibbs, G.L.

1984-01-01

The apparent resemblance between the stereotypic locomotor hyperactivity observed after either an injection of morphine or irradiation of the C57BL/6J mouse has suggested the possibility of similar biochemical and neuroanatomical substrates of these behaviors. In this study the authors made selective brain lesions in an attempt to reverse the locomotor response observed after morphine (30 mg/kg) or radiation (1500 rads /sup 60/Co) treatments. Lesions impinging on both the dorso-medial caudate and lateral septal nuclei caused a significant decrease in morphine-induced and radiogenic locomotion. Lesions of the individual brain areas did not significantly alter the opiate locomotor response. This reduction in locomotion could not be attributed to a generalized post-surgical lethargy since other brain lesions of similar size did not significantly suppress these behaviors. These data suggest the possibility of some common central nervous system mechanisms which may support the stereotypic locomotor hyperactivity observed in the C57BL/6J mouse after either morphine or radiation treatment

Olanzapine affects locomotor activity and meal size in male rats

NARCIS (Netherlands)

van der Zwaal, Esther M.; Luijendijk, Mieneke C. M.; Evers, Simon S.; la Fleur, Susanne E.; Adan, Roger A. H.

2010-01-01

Olanzapine is an antipsychotic drug that frequently induces weight gain accompanied by increased fat deposition as a side effect To investigate how olanzapine affects different aspects of energy balance we used male rats to determine effects on meal patterns food preference locomotor activity and

Cognitive Performance and Locomotor Adaptation in Persons With Anterior Cruciate Ligament Reconstruction.

Science.gov (United States)

Stone, Amanda E; Roper, Jaimie A; Herman, Daniel C; Hass, Chris J

2018-05-01

Persons with anterior cruciate ligament reconstruction (ACLR) show deficits in gait and neuromuscular control following rehabilitation. This altered behavior extends to locomotor adaptation and learning, however the contributing factors to this observed behavior have yet to be investigated. The purpose of this study was to assess differences in locomotor adaptation and learning between ACLR and controls, and identify underlying contributors to motor adaptation in these individuals. Twenty ACLR individuals and 20 healthy controls (CON) agreed to participate in this study. Participants performed four cognitive and dexterity tasks (local version of Trail Making Test, reaction time test, electronic pursuit rotor test, and the Purdue pegboard). Three-dimensional kinematics were also collected while participants walked on a split-belt treadmill. ACLR individuals completed the local versions of Trails A and Trails B significantly faster than CON. During split-belt walking, ACLR individuals demonstrated smaller step length asymmetry during EARLY and LATE adaptation, smaller double support asymmetry during MID adaptation, and larger stance time asymmetry during DE-ADAPT compared with CON. ACLR individuals performed better during tasks that required visual attention and task switching and were less perturbed during split-belt walking compared to controls. Persons with ACLR may use different strategies than controls, cognitive or otherwise, to adapt locomotor patterns.

Effects of noradrenaline on locomotor rhythm-generating networks in the isolated neonatal rat spinal cord

DEFF Research Database (Denmark)

Kiehn, O; Sillar, K T; Kjaerulff, O

1999-01-01

locomotor-like rhythm, in which activity alternated between the left and right sides, and between rostral and caudal roots on the same side. As shown previously, stable locomotor activity could be induced by bath application of N-methyl-D-aspartate (NMDA; 4-8.5 microM) and/or serotonin (5-HT; 4-20 micro......M). NA modulated this activity by decreasing the cycle frequency and increasing the ventral root burst duration. These effects were dose dependent in the concentration range 1-5 microM. In contrast, at no concentration tested did NA have consistent effects on burst amplitudes or on the background...... activity of the ongoing rhythm. Moreover, NA did not obviously affect the left/right and rostrocaudal alternation of the NMDA/5-HT rhythm. The NMDA/5-HT locomotor rhythm sometimes displayed a time-dependent breakdown in coordination, ultimately resulting in tonic ventral root activity. However...

Sleep pattern and locomotor activity are impaired by doxorubicin in non-tumor-bearing rats.

Science.gov (United States)

Lira, Fabio Santos; Esteves, Andrea Maculano; Pimentel, Gustavo Duarte; Rosa, José Cesar; Frank, Miriam Kannebley; Mariano, Melise Oliveira; Budni, Josiane; Quevedo, João; Santos, Ronaldo Vagner Dos; de Mello, Marco Túlio

2016-01-01

We sought explore the effects of doxorubicin on sleep patterns and locomotor activity. To investigate these effects, two groups were formed: a control group and a Doxorubicin (DOXO) group. Sixteen rats were randomly assigned to either the control or DOXO groups. The sleep patterns were examined by polysomnographic recording and locomotor activity was evaluated in an open-field test. In the light period, the total sleep time and slow wave sleep were decreased, while the wake after sleep onset and arousal were increased in the DOXO group compared with the control group (plocomotor activity.

Asymmetric operation of the locomotor central pattern generator in the neonatal mouse spinal cord

DEFF Research Database (Denmark)

Endo, Toshiaki; Kiehn, Ole

2008-01-01

The rhythmic voltage oscillations in motor neurons (MNs) during locomotor movements reflect the operation of the pre-MN central pattern generator (CPG) network. Recordings from MNs can thus be used as a method to deduct the organization of CPGs. Here, we use continuous conductance measurements...... of locomotor CPG. The extracted excitatory and inhibitory synaptic conductances varied between 2 and 56% of the mean total conductance. Analysis of the phase tuning of the extracted synaptic conductances in flexor and extensor MNs in the rostral lumbar cord showed that the flexor-phase-related synaptic...

MRT of the locomotor system. 4. rev. and enl. ed.

International Nuclear Information System (INIS)

Vahlensieck, Martin; Reiser, Maximilian

2015-01-01

The book on MRT of the locomotor system covers the following topics: relevant NMT imaging techniques, spinal cord, shoulder, elbows, wrist and fingers, hip region, knee, lower leg - ankle - foot, temporomandibular joint, skeletal muscles, bone marrow, bone and soft tissue tumors, osteoporosis, sacroiliac joint, jaw and periodontium.

NeuroRecovery Network provides standardization of locomotor training for persons with incomplete spinal cord injury.

Science.gov (United States)

Morrison, Sarah A; Forrest, Gail F; VanHiel, Leslie R; Davé, Michele; D'Urso, Denise

2012-09-01

To illustrate the continuity of care afforded by a standardized locomotor training program across a multisite network setting within the Christopher and Dana Reeve Foundation NeuroRecovery Network (NRN). Single patient case study. Two geographically different hospital-based outpatient facilities. This case highlights a 25-year-old man diagnosed with C4 motor incomplete spinal cord injury with American Spinal Injury Association Impairment Scale grade D. Standardized locomotor training program 5 sessions per week for 1.5 hours per session, for a total of 100 treatment sessions, with 40 sessions at 1 center and 60 at another. Ten-meter walk test and 6-minute walk test were assessed at admission and discharge across both facilities. For each of the 100 treatment sessions percent body weight support, average, and maximum treadmill speed were evaluated. Locomotor endurance, as measured by the 6-minute walk test, and overground gait speed showed consistent improvement from admission to discharge. Throughout training, the patient decreased the need for body weight support and was able to tolerate faster treadmill speeds. Data indicate that the patient continued to improve on both treatment parameters and walking function. Standardization across the NRN centers provided a mechanism for delivering consistent and reproducible locomotor training programs across 2 facilities without disrupting training or recovery progression. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

Energy Technology Data Exchange (ETDEWEB)

Zago, A. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Leão, R.M.; Carneiro-de-Oliveira, P.E. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos/Universidade Estadual de São Paulo, Araraquara, SP (Brazil); Marin, M.T.; Cruz, F.C. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Planeta, C.S. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos/Universidade Estadual de São Paulo, Araraquara, SP (Brazil)

2011-11-18

Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although crosssensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9% NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

International Nuclear Information System (INIS)

Zago, A.; Leão, R.M.; Carneiro-de-Oliveira, P.E.; Marin, M.T.; Cruz, F.C.; Planeta, C.S.

2011-01-01

Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although crosssensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9% NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

Directory of Open Access Journals (Sweden)

A. Zago

2012-01-01

Full Text Available Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although cross-sensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P 28-37 and adult (P60-67 rats received nicotine (0.4 mg/kg, sc or saline (0.9% NaCl, sc and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

A study on the multiple dynamic wavelength distribution for gigabit capable passive optical networks

Directory of Open Access Journals (Sweden)

Gustavo Adolfo Puerto Leguizamón

2014-04-01

Full Text Available This paper presents a data traffic based study aiming at evaluating the impact of dynamic wavelength allocation on a Gigabit capable Passive Optical Network (GPON. In Passive Optical Networks (PON, an Optical Line Terminal (OLT feeds different PONs in such a way that a given wavelength channel is evenly distributed between the Optical Network Units (ONU at each PON. However, PONs do not specify any kind of dynamic behavior on the way the wavelengths are allocated in the network, a completely static distribution is implemented instead. In thispaper we evaluate the network performance in terms of packet losses and throughput for a number of ONUs being out-of-profile while featuring a given percentage of traffic in excess for a fixed wavelength distribution and for multiple dynamic wavelength allocation. Results show that for a multichannel operation with four wavelengths, the network throughput increases up to a rough value of 19% while the packet losses drop from 22 % to 1.8 % as compared with a static wavelength distribution.

Local field potentials in the ventral tegmental area during cocaine-induced locomotor activation: Measurements in freely moving rats.

Science.gov (United States)

Harris Bozer, Amber L; Li, Ai-Ling; Sibi, Jiny E; Bobzean, Samara A M; Peng, Yuan B; Perrotti, Linda I

2016-03-01

The ventral tegmental area (VTA) has been established as a critical nucleus for processing behavioral changes that occur during psychostimulant use. Although it is known that cocaine induced locomotor activity is initiated in the VTA, not much is known about the electrical activity in real time. The use of our custom-designed wireless module for recording local field potential (LFP) activity provides an opportunity to confirm and identify changes in neuronal activity within the VTA of freely moving rats. The purpose of this study was to investigate the changes in VTA LFP activity in real time that underlie cocaine induced changes in locomotor behavior. Recording electrodes were implanted in the VTA of rats. Locomotor behavior and LFP activity were simultaneously recorded at baseline, and after saline and cocaine injections. Results indicate that cocaine treatment caused increases in both locomotor behavior and LFP activity in the VTA. Specifically, LFP activity was highest during the first 30 min following the cocaine injection and was most robust in Delta and Theta frequency bands; indicating the role of low frequency VTA activity in the initiation of acute stimulant-induced locomotor behavior. Our results suggest that LFP recording in freely moving animals can be used in the future to provide valuable information pertaining to drug induced changes in neural activity. Copyright © 2016 Elsevier Inc. All rights reserved.

Do social networks and technological capabilities help knowledge management?

Directory of Open Access Journals (Sweden)

Encarnación García-Sánchez

2017-12-01

Full Text Available Dynamic capabilities are currently becoming an important extension of the theory of resources and capabilities that enables companies to adapt better in the current competitive environment. This paper examines how knowledge management, a dynamic function related to management or administration of a set of knowledge flows, develops thanks to the greater dynamism of social networks. It then shows how this relationship is especially strengthened by different technological capabilities. To achieve these goals, the paper examines the main tools that permit companies to develop an ability to achieve competitive advantage relative to the technological capabilities of managers and workers, social networks and knowledge management.

Inbreeding affects locomotor activity in Drosophila melanogaster at different ages

DEFF Research Database (Denmark)

Manenti, Tommaso; Pertoldi, Cino; Nasiri Moghadam, Neda

2015-01-01

The ability to move is essential for many behavioural traits closely related to fitness. Here we studied the effect of inbreeding on locomotor activity (LA) of Drosophila melanogaster at different ages under both dark and light regimes. We expected to find a decreased LA in inbred lines compared...

Perceptual-motor regulation in locomotor pointing while approaching a curb.

Science.gov (United States)

Andel, Steven van; Cole, Michael H; Pepping, Gert-Jan

2018-02-01

Locomotor pointing is a task that has been the focus of research in the context of sport (e.g. long jumping and cricket) as well as normal walking. Collectively, these studies have produced a broad understanding of locomotor pointing, but generalizability has been limited to laboratory type tasks and/or tasks with high spatial demands. The current study aimed to generalize previous findings in locomotor pointing to the common daily task of approaching and stepping on to a curb. Sixteen people completed 33 repetitions of a task that required them to walk up to and step onto a curb. Information about their foot placement was collected using a combination of measures derived from a pressure-sensitive walkway and video data. Variables related to perceptual-motor regulation were analyzed on an inter-trial, intra-step and inter-step level. Similar to previous studies, analysis of the foot placements showed that, variability in foot placement decreased as the participants drew closer to the curb. Regulation seemed to be initiated earlier in this study compared to previous studies, as shown by a decreasing variability in foot placement as early as eight steps before reaching the curb. Furthermore, it was shown that when walking up to the curb, most people regulated their walk in a way so as to achieve minimal variability in the foot placement on top of the curb, rather than a placement in front of the curb. Combined, these results showed a strong perceptual-motor coupling in the task of approaching and stepping up a curb, rendering this task a suitable test for perceptual-motor regulation in walking. Copyright © 2017 Elsevier B.V. All rights reserved.

Locomotor Activity and Body Temperature Patterns over a Temperature Gradient in the Highveld Mole-Rat (Cryptomys hottentotus pretoriae).

Science.gov (United States)

Haupt, Meghan; Bennett, Nigel C; Oosthuizen, Maria K

2017-01-01

African mole-rats are strictly subterranean mammals that live in extensive burrow systems. High humidity levels in the burrows prevent mole-rats from thermoregulating using evaporative cooling. However, the relatively stable environment of the burrows promotes moderate temperatures and small daily temperature fluctuations. Mole-rats therefore display a relatively wide range of thermoregulation abilities. Some species cannot maintain their body temperatures at a constant level, whereas others employ behavioural thermoregulation. Here we test the effect of ambient temperature on locomotor activity and body temperature, and the relationship between the two parameters, in the highveld mole-rat. We exposed mole-rats to a 12L:12D and a DD light cycle at ambient temperatures of 30°C, 25°C and 20°C while locomotor activity and body temperature were measured simultaneously. In addition, we investigated the endogenous rhythms of locomotor activity and body temperature at different ambient temperatures. Mole-rats displayed nocturnal activity at all three ambient temperatures and were most active at 20°C, but least active at 30°C. Body temperature was highest at 30°C and lowest at 20°C, and the daily cycle was highly correlated with locomotor activity. We show that the mole-rats have endogenous rhythms for both locomotor activity and body temperature. However, the endogenous body temperature rhythm appears to be less robust compared to the locomotor activity rhythm. Female mole-rats appear to be more sensitive to temperature changes than males, increased heterothermy is evident at lower ambient temperatures, whilst males show smaller variation in their body temperatures with changing ambient temperatures. Mole-rats may rely more heavily on behavioural thermoregulation as it is more energy efficient in an already challenging environment.

Effects of nutmeg consumption on the open field locomotor activities ...

African Journals Online (AJOL)

... was a steady significant difference (p < 0.05) in the behaviours of line crossing and walling. There was no much significant changes (P<0.05) in the behaviours of hinding, grooming and defeacation between the Treatments and Control groups of animals. Keywords: Nutmeg, Wistar rats, Open field, Locomotor activities ...

Selection towards different adaptive optima drove the early diversification of locomotor phenotypes in the radiation of Neotropical geophagine cichlids.

Science.gov (United States)

Astudillo-Clavijo, Viviana; Arbour, Jessica H; López-Fernández, Hernán

2015-05-01

Simpson envisaged a conceptual model of adaptive radiation in which lineages diversify into "adaptive zones" within a macroevolutionary adaptive landscape. However, only a handful of studies have empirically investigated this adaptive landscape and its consequences for our interpretation of the underlying mechanisms of phenotypic evolution. In fish radiations the evolution of locomotor phenotypes may represent an important dimension of ecomorphological diversification given the implications of locomotion for feeding and habitat use. Neotropical geophagine cichlids represent a newly identified adaptive radiation and provide a useful system for studying patterns of locomotor diversification and the implications of selective constraints on phenotypic divergence in general. We use multivariate ordination, models of phenotypic evolution and posterior predictive approaches to investigate the macroevolutionary adaptive landscape and test for evidence of early divergence of locomotor phenotypes in Geophagini. The evolution of locomotor phenotypes was characterized by selection towards at least two distinct adaptive peaks and the early divergence of modern morphological disparity. One adaptive peak included the benthic and epibenthic invertivores and was characterized by fishes with deep, laterally compressed bodies that optimize precise, slow-swimming manoeuvres. The second adaptive peak resulted from a shift in adaptive optima in the species-rich ram-feeding/rheophilic Crenicichla-Teleocichla clade and was characterized by species with streamlined bodies that optimize fast starts and rapid manoeuvres. Evolutionary models and posterior predictive approaches favoured an early shift to a new adaptive peak over decreasing rates of evolution as the underlying process driving the early divergence of locomotor phenotypes. The influence of multiple adaptive peaks on the divergence of locomotor phenotypes in Geophagini is compatible with the expectations of an ecologically driven

Locomotor Performance During Rehabilitation of People With Lower Limb Amputation and Prosthetic Nonuse 12 Months After Discharge.

Science.gov (United States)

Roffman, Caroline E; Buchanan, John; Allison, Garry T

2016-07-01

It is recognized that multifactorial assessments are needed to evaluate balance and locomotor function in people with lower limb amputation. There is no consensus on whether a single screening tool could be used to identify future issues with locomotion or prosthetic use. The purpose of this study was to determine whether different tests of locomotor performance during rehabilitation were associated with significantly greater risk of prosthetic abandonment at 12 months postdischarge. This was a retrospective cohort study. Data for descriptive variables and locomotor tests (ie, 10-Meter Walk Test [10MWT], Timed "Up & Go" Test [TUGT], Six-Minute Walk Test [6MWT], and Four Square Step Test [FSST]) were abstracted from the medical records of 201 consecutive participants with lower limb amputation. Participants were interviewed and classified as prosthetic users or nonusers at 12 months postdischarge. The Mann-Whitney U test was used to analyze whether there were differences in locomotor performance. Receiver operating characteristic curves were generated to determine performance thresholds, and relative risk (RR) was calculated for nonuse. At 12 months postdischarge, 18% (n=36) of the participants had become prosthetic nonusers. Performance thresholds, area under the curve (AUC), and RR of nonuse (95% confidence intervals [CI]) were: for the 10MWT, if walking speed was ≤0.44 ms(-1) (AUC=0.743), RR of nonuse=2.76 (95% CI=1.83, 3.79; PLocomotor performance during rehabilitation may predict future risk of prosthetic nonuse. It may be implied that the 10MWT has the greatest clinical utility as a single screening tool for prosthetic nonuse, given the highest proportion of participants were able to perform this test early in rehabilitation. However, as locomotor skills improve, other tests (in particular, the 6MWT) have specific clinical utility. To fully enable implementation of these locomotor criteria for prosthetic nonuse into clinical practice, validation is warranted

Effects of cocaine on norepinephrine stimulated phosphoinositide hydrolysis and locomotor activity in rat

International Nuclear Information System (INIS)

Mosaddeghi, M.

1989-01-01

The function of α 1 -adrenoceptors was determined by stimulating cortical tissue slices, which were pre-labeled with [ 3 H]inositol, with norepinephrine (NE) in the presence of 8 mM LiCl. Results of in vitro studies showed that cocaine 10 μM potentiated maximal NE-stimulated PI hydrolysis by 30%. In addition, the EC 50 was decreased from 3.93 ± 0.42 to 1.91 ± 0.31 μM NE. Concentrations of 0.1-100 μM and 0.1-10 μM cocaine enhanced PI hydrolysis stimulated by 0.3 and 3 μM NE, respectively. The concentration-effect curves for NE-stimulated PI hydrolysis were shifted to the right 100-fold in the presence of 0.1 μM prazosin. Cocaine (10 μM) did not potentiate NE-stimulated PI hydrolysis in the presence of 0.1 μM prazosin. [ 3 H]Prazosin saturation and NE [ 3 H]prazosin competition binding studies using crude membrane preparations showed that 10 μM cocaine did not alter binding parameters B max , K d , Hill slope, and IC 50 . Together, these results implied that cocaine in vitro potentiated NE-stimulated PI hydrolysis by blocking NE reuptake. For in vivo studies, the locomotor activity was determined after an acute or chronic injections of either cocaine or saline. Cocaine or saline-treated rats were killed after measurement of the locomotor activity, and NE-stimulated PI hydrolysis was measured. Acute administration of cocaine 3.2-42 mg/kg (i.p.) produced an inverted U shaped dose-response curve on locomotor activity. The peak increase in locomotor activity was at 32 mg/kg cocaine. A dose of 42 mg/kg cocaine produced a significant depression of maximal NE-stimulated PI hydrolysis

Rapid recovery and altered neurochemical dependence of locomotor central pattern generation following lumbar neonatal spinal cord injury.

Science.gov (United States)

Züchner, Mark; Kondratskaya, Elena; Sylte, Camilla B; Glover, Joel C; Boulland, Jean-Luc

2018-01-15

Spinal compression injury targeted to the neonatal upper lumbar spinal cord, the region of highest hindlimb locomotor rhythmogenicity, leads to an initial paralysis of the hindlimbs. Behavioural recovery is evident within a few days and approaches normal function within about 3 weeks. Fictive locomotion in the isolated injured spinal cord cannot be elicited by a neurochemical cocktail containing NMDA, dopamine and serotonin 1 day post-injury, but can 3 days post-injury as readily as in the uninjured spinal cord. Low frequency coordinated rhythmic activity can be elicited in the isolated uninjured spinal cord by NMDA + dopamine (without serotonin), but not in the isolated injured spinal cord. In both the injured and uninjured spinal cord, eliciting bona fide fictive locomotion requires the additional presence of serotonin. Following incomplete compression injury in the thoracic spinal cord of neonatal mice 1 day after birth (P1), we previously reported that virtually normal hindlimb locomotor function is recovered within about 3 weeks despite substantial permanent thoracic tissue loss. Here, we asked whether similar recovery occurs following lumbar injury that impacts more directly on the locomotor central pattern generator (CPG). As in thoracic injuries, lumbar injuries caused about 90% neuronal loss at the injury site and increased serotonergic innervation below the injury. Motor recovery was slower after lumbar than thoracic injury, but virtually normal function was attained by P25 in both cases. Locomotor CPG status was tested by eliciting fictive locomotion in isolated spinal cords using a widely used neurochemical cocktail (NMDA, dopamine, serotonin). No fictive locomotion could be elicited 1 day post-injury, but could within 3 days post-injury as readily as in age-matched uninjured control spinal cords. Burst patterning and coordination were largely similar in injured and control spinal cords but there were differences. Notably, in both groups there

Volumetric changes in the aging rat brain and its impact on cognitive and locomotor functions.

Science.gov (United States)

Hamezah, Hamizah Shahirah; Durani, Lina Wati; Ibrahim, Nor Faeizah; Yanagisawa, Daijiro; Kato, Tomoko; Shiino, Akihiko; Tanaka, Sachiko; Damanhuri, Hanafi Ahmad; Ngah, Wan Zurinah Wan; Tooyama, Ikuo

2017-12-01

Impairments in cognitive and locomotor functions usually occur with advanced age, as do changes in brain volume. This study was conducted to assess changes in brain volume, cognitive and locomotor functions, and oxidative stress levels in middle- to late-aged rats. Forty-four male Sprague-Dawley rats were divided into four groups: 14, 18, 23, and 27months of age. 1 H magnetic resonance imaging (MRI) was performed using a 7.0-Tesla MR scanner system. The volumes of the lateral ventricles, medial prefrontal cortex (mPFC), hippocampus, striatum, cerebellum, and whole brain were measured. Open field, object recognition, and Morris water maze tests were conducted to assess cognitive and locomotor functions. Blood was taken for measurements of malondialdehyde (MDA), protein carbonyl content, and antioxidant enzyme activity. The lateral ventricle volumes were larger, whereas the mPFC, hippocampus, and striatum volumes were smaller in 27-month-old rats than in 14-month-old rats. In behavioral tasks, the 27-month-old rats showed less exploratory activity and poorer spatial learning and memory than did the 14-month-old rats. Biochemical measurements likewise showed increased MDA and lower glutathione peroxidase (GPx) activity in the 27-month-old rats. In conclusion, age-related increases in oxidative stress, impairment in cognitive and locomotor functions, and changes in brain volume were observed, with the most marked impairments observed in later age. Copyright © 2017. Published by Elsevier Inc.

Effects of scallop shell extract on scopolamine-induced memory impairment and MK801-induced locomotor activity

OpenAIRE

HASEGAWA, Yasushi; INOUE, Tatsuro; KAWAMINAMI, Satoshi; FUJITA, Miho

2016-01-01

ObjectiveTo evaluate the neuroprotective effects of the organic components of scallop shells (scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibenzo (a,d) cyclohepten-5,10-imine (MK801).MethodsEffect of the scallop shell extract on memory impairment and locomotor activity was investigated using the Y-maze test, the Morris water maze test, and the open field test.ResultsScallop shell extract significantly reduced scopolami...

Three-axis optical force plate for studies in small animal locomotor mechanics

International Nuclear Information System (INIS)

Hsieh, S. Tonia

2006-01-01

The use of force plates to measure whole-body locomotor mechanics is a well-established technique. However, commercially available force plates are not sensitive enough for use on small-bodied vertebrates or invertebrates. The standard design for single- and multiple-axis, high-sensitivity force plates built by individual research groups uses semiconductor foil strain gauges to measure deflections; yet foil strain gauges are highly temperature and position sensitive, resulting in a drifting base line and nonlinear responses. I present here a design for a three-axis optical force plate that was successfully calibrated to measure forces as small as 1.5 mN and is capable of determining the position of center of pressure with a mean error of 0.07 cm along the X axis and 0.13 cm along the Y axis. Using optical sensors instead of foil strain gauges to measure deflection, this force plate is not subject to temperature-related drift and is more robust against slight positioning inaccuracies. This force plate was used to measure forces produced by amphibious fishes weighing less than 2 g as they jumped off the force platform

The thermal dependency of locomotor performance evolves rapidly within an invasive species.

Science.gov (United States)

Kosmala, Georgia K; Brown, Gregory P; Christian, Keith A; Hudson, Cameron M; Shine, Richard

2018-05-01

Biological invasions can stimulate rapid shifts in organismal performance, via both plasticity and adaptation. We can distinguish between these two proximate mechanisms by rearing offspring from populations under identical conditions and measuring their locomotor abilities in standardized trials. We collected adult cane toads ( Rhinella marina ) from invasive populations that inhabit regions of Australia with different climatic conditions. We bred those toads and raised their offspring under common-garden conditions before testing their locomotor performance. At high (but not low) temperatures, offspring of individuals from a hotter location (northwestern Australia) outperformed offspring of conspecifics from a cooler location (northeastern Australia). This disparity indicates that, within less than 100 years, thermal performance in cane toads has adapted to the novel abiotic challenges that cane toads have encountered during their invasion of tropical Australia.

Effects of opioid drugs on dopamine mediated locomotor activity in rats

Energy Technology Data Exchange (ETDEWEB)

Leathern, L L

1986-01-01

Opioid drugs influence various behavioural parameters including locomotor activity in experimental animals. The interaction between the opioid and dopaminergic systems is one possible explanation for the effect of opioid drugs on locomotor activity. In this study behavioural and biochemical assays were done to investigate the interaction between the opioid and dopaminergic systems. Behavioural studies were done by measurement of locomotor activity (LA) of rats after acute or chronic pretreatment with opioid andor dopaminergic drugs. Biochemical studies were in the form of radioligand binding assays, the effect on the number (Bmax) and affinity (K/sub D/) of receptors was measured after chronic pretreatment with opioid andor dopaminergic drugs. The opioid drugs used are morphine, nalbuphine and naloxone. Dopaminergic drugs used included: agonists-apomorphine and piribedil; antagonists-pimozide, haloperidol, chlorpromazine. In the acute situation increased LA was obtained with morphine and the DA agonists. A correlation between the behavioural and biochemical assays was found. Chronic pretreatment with morphine enhanced apomorphine induced LA, this supersensitivity was also measured as an increased receptor density (Bmax) of D2 receptors in the striatum. Chronic morphine pretreatment caused a decrease in morphine induced LA, while this subsensitivity was not apparent in the ligand binding assays - where no change in receptor number was observed. Chronic naloxone pretreatment enhanced morphine induced LA, as well as increased the Bmax of opioid receptors in the whole brain. It is concluded that an interaction between the opioid and dopaminergic systems does exist, and may account for the mechanism of action of the opioids.

Mechanisms of Left-Right Coordination in Mammalian Locomotor Pattern Generation Circuits: A Mathematical Modeling View

Science.gov (United States)

Talpalar, Adolfo E.; Rybak, Ilya A.

2015-01-01

The locomotor gait in limbed animals is defined by the left-right leg coordination and locomotor speed. Coordination between left and right neural activities in the spinal cord controlling left and right legs is provided by commissural interneurons (CINs). Several CIN types have been genetically identified, including the excitatory V3 and excitatory and inhibitory V0 types. Recent studies demonstrated that genetic elimination of all V0 CINs caused switching from a normal left-right alternating activity to a left-right synchronized “hopping” pattern. Furthermore, ablation of only the inhibitory V0 CINs (V0D subtype) resulted in a lack of left-right alternation at low locomotor frequencies and retaining this alternation at high frequencies, whereas selective ablation of the excitatory V0 neurons (V0V subtype) maintained the left–right alternation at low frequencies and switched to a hopping pattern at high frequencies. To analyze these findings, we developed a simplified mathematical model of neural circuits consisting of four pacemaker neurons representing left and right, flexor and extensor rhythm-generating centers interacting via commissural pathways representing V3, V0D, and V0V CINs. The locomotor frequency was controlled by a parameter defining the excitation of neurons and commissural pathways mimicking the effects of N-methyl-D-aspartate on locomotor frequency in isolated rodent spinal cord preparations. The model demonstrated a typical left-right alternating pattern under control conditions, switching to a hopping activity at any frequency after removing both V0 connections, a synchronized pattern at low frequencies with alternation at high frequencies after removing only V0D connections, and an alternating pattern at low frequencies with hopping at high frequencies after removing only V0V connections. We used bifurcation theory and fast-slow decomposition methods to analyze network behavior in the above regimes and transitions between them. The model

Transforming organizational capabilities in strategizing

DEFF Research Database (Denmark)

Jørgensen, Claus; Friis, Ole Uhrskov; Koch, Christian

2014-01-01

Offshored and networked enterprises are becoming an important if not leading organizational form and this development seriously challenges their organizational capabilities. More specifically, over the last years, SMEs have commenced entering these kinds of arrangements. As the organizational...... capabilities of SMEs are limited at the outset, even more emphasis is needed regarding the issues of developing relevant organizational capabilities. This paper aims at investigating how capabilities evolve during an offshoring process of more than 5 years in two Danish SMEs, i.e. not only short- but long......-term evolvements within the companies. We develop our framework of understanding organizational capabilities drawing on dynamic capability, relational capability and strategy as practice concepts, appreciating the performative aspects of developing new routines. Our two cases are taken from one author’s Ph...

Plateau properties in mammalian spinal interneurons during transmitter-induced locomotor activity

DEFF Research Database (Denmark)

Kiehn, O.; Johnson, B. R.; Raastad, M.

1996-01-01

We examined the organization of spinal networks controlling locomotion in the isolated spinal cord of the neonatal rat, and in this study we provide the first demonstration of plateau and bursting mechanisms in mammalian interneurons that show locomotor-related activity. Using tight-seal whole...

Engagement of the Rat Hindlimb Motor Cortex across Natural Locomotor Behaviors

NARCIS (Netherlands)

DiGiovanna, J.; Dominici, N.; Friedli, L.; Rigosa, J.; Duis, S.; Kreider, J.; Beauparlant, J.; van den Brand, R.; Schieppati, M.; Micera, S.; Courtine, G.

2016-01-01

Contrary to cats and primates, cortical contribution to hindlimb locomotor movements is not critical in rats. However, the importance of the motor cortex to regain locomotion after neurological disorders in rats suggests that cortical engagement in hindlimb motor control may depend on the behavioral

Low dose radiation enhances the Locomotor activity of D. melanogaster

Energy Technology Data Exchange (ETDEWEB)

Seong, Ki Moon; Lee, Buyng Sub; Nam Seon Young; Kim, Ji Young; Yang, Kwang Hee; Choi, Tae In; Kim, Cha Soon [Radiation Effect Research Team, Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., Gyeongju (Korea, Republic of)

2013-04-15

Mild stresses at low level including radiation can induce the beneficial effects in many vertebrate and invertebrate species. However, a large amount of studies in radiation biology have focused on the detrimental effects of high dose radiation (HDR) such as the increased incidence of cancers and developmental diseases. Low dose radiation (LDR) induces biologically favorable effects in diverse fields, for example, cancer development, genomic instability, immune response, and longevity. Our previous data indicated that LDR promotes cells proliferation of which degree is not much but significant, and microarray data explained that LDR irradiated fruit flies showing the augmented immunity significantly changed the program for gene expression of many genes in Gene Ontology (GO) categories related to metabolic process. Metabolic process in development one of major contributors in organism growth, interbreeding, motility, and aging. Therefore, it is valuable to examine whether LDR change the physiological parameters related to metabolism, and how LDR regulates the metabolism in D. melanogaster. In this study, to investigate that LDR influences change of the metabolism, a representative parameter, locomotor activity. In addition, the activation of several cellular signal molecules was determined to investigate the specific molecular mechanism of LDR effects on the metabolism. We explored whether ionizing radiation affects the motility activity. We performed the RING assays to evaluate the locomotor activity, a representative parameter presenting motility of fruit flies. HDR dramatically decreased the motor activity of irradiated flies. Surprisingly, the irradiated flies at low dose radiation in both acute and chronic showed the significantly increased locomotor activity, compared to non-irradiated flies. Irradiation would induce change of the several signal pathways for flies to respond to it. The activation of some proteins involved in the cells proliferation and stress

Dentate gyrus neurogenesis ablation via cranial irradiation enhances morphine self-administration and locomotor sensitization.

Science.gov (United States)

Bulin, Sarah E; Mendoza, Matthew L; Richardson, Devon R; Song, Kwang H; Solberg, Timothy D; Yun, Sanghee; Eisch, Amelia J

2018-03-01

Adult dentate gyrus (DG) neurogenesis is important for hippocampal-dependent learning and memory, but the role of new neurons in addiction-relevant learning and memory is unclear. To test the hypothesis that neurogenesis is involved in the vulnerability to morphine addiction, we ablated adult DG neurogenesis and examined morphine self-administration (MSA) and locomotor sensitization. Male Sprague-Dawley rats underwent hippocampal-focused, image-guided X-ray irradiation (IRR) to eliminate new DG neurons or sham treatment (Sham). Six weeks later, rats underwent either MSA (Sham = 16, IRR = 15) or locomotor sensitization (Sham = 12, IRR = 12). Over 21 days of MSA, IRR rats self-administered ~70 percent more morphine than Sham rats. After 28 days of withdrawal, IRR rats pressed the active lever 40 percent more than Sham during extinction. This was not a general enhancement of learning or locomotion, as IRR and Sham groups had similar operant learning and inactive lever presses. For locomotor sensitization, both IRR and Sham rats sensitized, but IRR rats sensitized faster and to a greater extent. Furthermore, dose-response revealed that IRR rats were more sensitive at a lower dose. Importantly, these increases in locomotor activity were not apparent after acute morphine administration and were not a byproduct of irradiation or post-irradiation recovery time. Therefore, these data, along with other previously published data, indicate that reduced hippocampal neurogenesis confers vulnerability for multiple classes of drugs. Thus, therapeutics to specifically increase or stabilize hippocampal neurogenesis could aid in preventing initial addiction as well as future relapse. © 2017 Society for the Study of Addiction.

Capabilities for managing service innovation: towards a conceptual framework

NARCIS (Netherlands)

den Hertog, P.; van der Aa, W.; de Jong, M.W.

2010-01-01

Purpose - The purpose of this paper is to identify and reflect on a set of dynamic capabilities for managing service innovation and applies a dynamic capabilities view (DCV) of firms for managing service innovation. Design/methodology/approach - This theoretical paper offers a conceptual framework

Prenatal Iron Deficiency in Guinea Pigs Increases Locomotor Activity but Does Not Influence Learning and Memory

OpenAIRE

Fiset, Catherine; Rioux, France M.; Surette, Marc E.; Fiset, Sylvain

2015-01-01

The objective of the current study was to determine whether prenatal iron deficiency induced during gestation in guinea pigs affected locomotor activity and learning and memory processes in the progeny. Dams were fed either iron-deficient anemic or iron-sufficient diets throughout gestation and lactation. After weaning, all pups were fed an iron-sufficient diet. On postnatal day 24 and 40, the pups' locomotor activity was observed within an open-field test, and from postnatal day 25 to 40, th...

Improved fault ride through capability of DFIG based wind turbines using synchronous reference frame control based dynamic voltage restorer.

Science.gov (United States)

Rini Ann Jerin, A; Kaliannan, Palanisamy; Subramaniam, Umashankar

2017-09-01

Fault ride through (FRT) capability in wind turbines to maintain the grid stability during faults has become mandatory with the increasing grid penetration of wind energy. Doubly fed induction generator based wind turbine (DFIG-WT) is the most popularly utilized type of generator but highly susceptible to the voltage disturbances in grid. Dynamic voltage restorer (DVR) based external FRT capability improvement is considered. Since DVR is capable of providing fast voltage sag mitigation during faults and can maintain the nominal operating conditions for DFIG-WT. The effectiveness of the DVR using Synchronous reference frame (SRF) control is investigated for FRT capability in DFIG-WT during both balanced and unbalanced fault conditions. The operation of DVR is confirmed using time-domain simulation in MATLAB/Simulink using 1.5MW DFIG-WT. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Efficacy of Stochastic Vestibular Stimulation to Improve Locomotor Performance in a Discordant Sensory Environment

Science.gov (United States)

Temple, D. R.; De Dios, Y. E.; Layne, C. S.; Bloomberg, J. J.; Mulavara, A. P.

2016-01-01

Astronauts exposed to microgravity face sensorimotor challenges incurred when readapting to a gravitational environment. Sensorimotor Adaptability (SA) training has been proposed as a countermeasure to improve locomotor performance during re-adaptation, and it is suggested that the benefits of SA training may be further enhanced by improving detection of weak sensory signals via mechanisms such as stochastic resonance when a non-zero level of stochastic white noise based electrical stimulation is applied to the vestibular system (stochastic vestibular stimulation, SVS). The purpose of this study was to test the efficacy of using SVS to improve short-term adaptation in a sensory discordant environment during performance of a locomotor task.

Influence of temperature on daily locomotor activity in the crab Uca pugilator.

Directory of Open Access Journals (Sweden)

Audrey M Mat

Full Text Available Animals living in the intertidal zone are exposed to prominent temperature changes. To cope with the energetic demands of environmental thermal challenges, ectotherms rely mainly on behavioral responses, which may change depending on the time of the day and seasonally. Here, we analyze how temperature shapes crabs' behavior at 2 different times of the year and show that a transition from constant cold (13.5°C to constant warm (17.5°C water temperature leads to increased locomotor activity levels throughout the day in fiddler crabs (Uca pugilator collected during the summer. In contrast, the same transition in environmental temperature leads to a decrease in the amplitude of the daily locomotor activity rhythm in crabs collected during the winter. In other words, colder temperatures during the cold season favor a more prominent diurnal behavior. We interpret this winter-summer difference in the response of daily locomotor activity to temperature changes within the framework of the circadian thermoenergetics hypothesis, which predicts that a less favorable energetic balance would promote a more diurnal activity pattern. During the winter, when the energetic balance is likely less favorable, crabs would save energy by being more active during the expected high-temperature phase of the day-light phase-and less during the expected low-temperature phase of the day-dark phase. Our results suggest that endogenous rhythms in intertidal ectotherms generate adaptive behavioral programs to cope with thermoregulatory demands of the intertidal habitat.

Locomotor Sub-functions for Control of Assistive Wearable Robots

OpenAIRE

Sharbafi, Maziar A.; Seyfarth, Andre; Zhao, Guoping

2017-01-01

A primary goal of comparative biomechanics is to understand the fundamental physics of locomotion within an evolutionary context. Such an understanding of legged locomotion results in a transition from copying nature to borrowing strategies for interacting with the physical world regarding design and control of bio-inspired legged robots or robotic assistive devices. Inspired from nature, legged locomotion can be composed of three locomotor sub-functions, which are intrinsically interrelated:...

Structural attributes contributing to locomotor performance in the ostrich

OpenAIRE

Schaller, Nina U.

2008-01-01

As the fastest long-endurance runner, the bipedal ostrich (Struthio camelus) was selected as a prime model organism to investigate the physical attributes underlying this advanced locomotor performance. A specific integrative approach combining morphological, morphometric, kinematic and pedobarographic methods was developed. The comparative morphometric analysis of the hind limbs of all ratite species revealed that leg segment ratios in the ostrich are the most specialised for efficient locom...

Muscle Spindles and Locomotor Control-An Unrecognized Falls Determinant?

OpenAIRE

Marks Ray

2015-01-01

BACKGROUND: Historically, evidence muscle spindles might be involved in locomotion was provided by their presence in tetrapod antigravity muscles associated with posture and locomotion. Later, Brodal (1962) noted muscle spindles in all muscles of locomotion. To unravel the complexity of the muscle spindle and its role in human locomotor control many investigators have since conducted lesion and/or anaesthesia studies in subhuman species and human contexts. QUESTIONS: How ...

Injury scores and locomotor disorders of Holstein cows in a free-stall facility with different beds

OpenAIRE

Cecchin, Daiane; Universidade Federal de Lavras - UFLA Lavras - MG; Campos, Alessandro Torres; Universidade Federal de Lavras - UFLA Lavras - MG; Pires, Maria de Fátima Ávila; Sousa, Francine Aparecida; Universidade Federal de Lavras - UFLA Lavras - MG; Amaral, Pedro Ivo Sodré; Universidade Federal de Lavras - UFLA Lavras - MG; Yanagi Junior, Tadayuki; Universidade Federal de Lavras - UFLA Lavras - MG; Ferreira, Suane Alves; Médica Veterinária – UNIPAC Juiz de Fora, MG.; Souza, Myriam Cristiane Morais; Graduanda em Medicina Veterinária – UNIPAC Juiz de Fora, MG.; Cecchin, Diego; Especialista em Gestão – UPF, Passo Fundo, RS

2015-01-01

The aim of the present study was to evaluate hock and knee injuries and locomotor disorders in 36 multiparous Holstein cows confined in a free-stall model system with two types of beds at Embrapa Dairy Cattle in the city of Coronel Pacheco / MG. Rubber composite beds and sand beds were compared and the hock and knee injuries and locomotor disorders were assessed for severity scores. There was no difference between the scores or hock lesions observed at the beginning and end of the trial perio...

The precision of locomotor odometry in humans.

Science.gov (United States)

Durgin, Frank H; Akagi, Mikio; Gallistel, Charles R; Haiken, Woody

2009-03-01

Two experiments measured the human ability to reproduce locomotor distances of 4.6-100 m without visual feedback and compared distance production with time production. Subjects were not permitted to count steps. It was found that the precision of human odometry follows Weber's law that variability is proportional to distance. The coefficients of variation for distance production were much lower than those measured for time production for similar durations. Gait parameters recorded during the task (average step length and step frequency) were found to be even less variable suggesting that step integration could be the basis for non-visual human odometry.

Human spinal locomotor control is based on flexibly organized burst generators

OpenAIRE

Danner, Simon M.; Hofstoetter, Ursula S.; Freundl, Brigitta; Binder, Heinrich; Mayr, Winfried; Rattay, Frank; Minassian, Karen

2015-01-01

Understanding the organisation of human spinal locomotor circuitry after severe CNS damage is essential for improving neurorehabilitation strategies. Danner et al. present evidence of flexibly organised burst-generating elements within the functionally isolated human lumbosacral spinal cord that generate rhythmic patterns in response to constant, repetitive epidural stimulation.

Self-Motion Perception during Locomotor Recalibration: More than Meets the Eye

Science.gov (United States)

Durgin, Frank H.; Pelah, Adar; Fox, Laura F.; Lewis, Jed; Kane, Rachel; Walley, Katherine A.

2005-01-01

Do locomotor after effects depend specifically on visual feedback? In 7 experiments, 116 college students were tested, with closed eyes, at stationary running or at walking to a previewed target after adaptation, with closed eyes, to treadmill locomotion. Subjects showed faster inadvertent drift during stationary running and increased distance…

The H2O2 scavenger ebselen decreases ethanol-induced locomotor stimulation in mice.

Science.gov (United States)

Ledesma, Juan Carlos; Font, Laura; Aragon, Carlos M G

2012-07-01

In the brain, the enzyme catalase by reacting with H(2)O(2) forms Compound I (catalase-H(2)O(2) system), which is the main system of central ethanol metabolism to acetaldehyde. Previous research has demonstrated that acetaldehyde derived from central-ethanol metabolism mediates some of the psychopharmacological effects produced by ethanol. Manipulations that modulate central catalase activity or sequester acetaldehyde after ethanol administration modify the stimulant effects induced by ethanol in mice. However, the role of H(2)O(2) in the behavioral effects caused by ethanol has not been clearly addressed. The present study investigated the effects of ebselen, an H(2)O(2) scavenger, on ethanol-induced locomotion. Swiss RjOrl mice were pre-treated with ebselen (0-50mg/kg) intraperitoneally (IP) prior to administration of ethanol (0-3.75g/kg; IP). In another experiment, animals were pre-treated with ebselen (0 or 25mg/kg; IP) before caffeine (15mg/kg; IP), amphetamine (2mg/kg; IP) or cocaine (10mg/kg; IP) administration. Following these treatments, animals were placed in an open field to measure their locomotor activity. Additionally, we evaluated the effect of ebselen on the H(2)O(2)-mediated inactivation of brain catalase activity by 3-amino-1,2,4-triazole (AT). Ebselen selectively prevented ethanol-induced locomotor stimulation without altering the baseline activity or the locomotor stimulating effects caused by caffeine, amphetamine and cocaine. Ebselen reduced the ability of AT to inhibit brain catalase activity. Taken together, these data suggest that a decline in H(2)O(2) levels might result in a reduction of the ethanol locomotor-stimulating effects, indicating a possible role for H(2)O(2) in some of the psychopharmacological effects produced by ethanol. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Effects of zacopride and BMY25801 (batanopride) on radiation-induced emesis and locomotor behavior in the ferret

International Nuclear Information System (INIS)

King, G.L.; Landauer, M.R.

1990-01-01

The antiemetic and locomotor effects of two substituted benzamides, zacopride and batanopride (BMY25801), were compared in ferrets after bilateral 60Co irradiation at 2, 4 or 6 Gy. Both zacopride and BMY25801 were effective against emesis and related signs. Zacopride, tested at several doses (0.003, 0.03 and 0.3 mg/kg), appeared to be more potent because it abolished emesis at 100-fold lower doses than did BMY25801 (3 mg/kg). The ED50 value for the antiemetic effect of zacopride was 0.026 mg/kg (confidence levels = 0.0095, 0.072 mg/kg). However, analysis of emetic parameters recorded from vomiting animals (e.g., latency to first emesis) demonstrated that BMY25801 provided greater antiemetic protection in this population than zacopride without any apparent side effects. Locomotor activity was significantly depressed by both radiation (all doses) and zacopride alone (0.03 mg/kg and 0.3 mg/kg). BMY25801 alone did not affect locomotor activity, and protected against the radiation-induced locomotor decrement. Although zacopride potentiated the locomotor decrement to radiation, no clear dose-response relationship was evident. Bilateral abdominal vagotomy significantly increased the latency to the first emetic episode and significantly reduced the number of retches, but did not alter the duration of the prodromal response to 4-Gy irradiation. Unilateral vagotomies had no effect. Zacopride (at 0.03 mg/kg and 0.3 mg/kg) remained an effective antiemetic in animals that received a bilateral vagotomy, abolishing emesis in four of eight and two of eight ferrets, respectively. These data suggest that the antiemetic action of zacopride does not fully depend on intact vagal innervation and also acts via other pathways

Human spinal locomotor control is based on flexibly organized burst generators.

Science.gov (United States)

Danner, Simon M; Hofstoetter, Ursula S; Freundl, Brigitta; Binder, Heinrich; Mayr, Winfried; Rattay, Frank; Minassian, Karen

2015-03-01

Constant drive provided to the human lumbar spinal cord by epidural electrical stimulation can cause local neural circuits to generate rhythmic motor outputs to lower limb muscles in people paralysed by spinal cord injury. Epidural spinal cord stimulation thus allows the study of spinal rhythm and pattern generating circuits without their configuration by volitional motor tasks or task-specific peripheral feedback. To reveal spinal locomotor control principles, we studied the repertoire of rhythmic patterns that can be generated by the functionally isolated human lumbar spinal cord, detected as electromyographic activity from the legs, and investigated basic temporal components shared across these patterns. Ten subjects with chronic, motor-complete spinal cord injury were studied. Surface electromyographic responses to lumbar spinal cord stimulation were collected from quadriceps, hamstrings, tibialis anterior, and triceps surae in the supine position. From these data, 10-s segments of rhythmic activity present in the four muscle groups of one limb were extracted. Such samples were found in seven subjects. Physiologically adequate cycle durations and relative extension- and flexion-phase durations similar to those needed for locomotion were generated. The multi-muscle activation patterns exhibited a variety of coactivation, mixed-synergy and locomotor-like configurations. Statistical decomposition of the electromyographic data across subjects, muscles and samples of rhythmic patterns identified three common temporal components, i.e. basic or shared activation patterns. Two of these basic patterns controlled muscles to contract either synchronously or alternatingly during extension- and flexion-like phases. The third basic pattern contributed to the observed muscle activities independently from these extensor- and flexor-related basic patterns. Each bifunctional muscle group was able to express both extensor- and flexor-patterns, with variable ratios across the

[INFLUENCE OF IONIZING RADIATION ON THE LOCOMOTOR ACTIVITY AND BODY WEIGHT OF RATS].

Science.gov (United States)

Saimova, A; Chaizhunusоva, N; Kairkhanova, Y; Uzbеkоv, D; Hоshi, М

2017-02-01

The aim of our study was to study influence of ionizing radiation on the locomotor activity and body weight of rats, for this animals was irradiated by via inhalation. Beta- emitter 56Mn was obtained by neutron activation of powdered MnО2 by using nuclear reactor IVG.1M (experimental facility «Baikal-1», Kurchatov, Kazakhstan). Exposure of rats to radioactive powder had two way, the first experiment was contained only air filter for animal's breathing and the second with the system of forced ventilation. Also we developed the method for observation of the locomotor activity of rats, based on quantitative data. The experiment was conducted on 8 «Wistar» breed white laboratory rats. Statistical analysis was performed using descriptive statistics and non-parametric test. Based on our data, we can say that our method has the advantage over the others is that there is no need to move about the animal out of the box in the test field. So we reduce animal stress factor, as the transfer of an animal from one to second place creates additional stress for him. The initial activity of the pulverized powder in both experiments were 2,74х108Bq, but in the second experiment when we used the system of forced ventilation, internal radiation doses were 0.041±0.0075 Gy, this didn't have effect on locomotor activity of rats (Z= -0,841, р=0,4). In the first experiment where we used only air filter for animal's breathing internal radiation doses were 0.15±0.025 Gr, that showed a decrease in locomotor activity in rats (Z=-6,653, р=0,001). After exposure to ionizing radiation changes in the mammals' weight were not found. Thus, based on our data we have made conclusion, that even after a single irradiation at low dose 0.15±0.025 Gr changes occur in the nervous system.

Dose and time relationships of the radioprotector WR-2721 on locomotor activity in mice

International Nuclear Information System (INIS)

Landauer, M.R.; Davis, H.D.; Dominitz, J.A.; Weiss, J.F.

1987-01-01

The effects of the radioprotector S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721) on locomotor activity were evaluated in CD2F1 male mice. Separate groups of animals (N = 10/group) received an IP injection of vehicle, 25, 50, 100, 200, or 400 mg/kg of WR-2721 immediately before testing. Horizontal and vertical activity were measured using a Digiscan automated animal activity monitor. The latency to onset and duration of action of each dose of the radioprotector were recorded. For both behavioral measures, a significant reduction was observed in activity at doses of 200 and 400 mg/kg. A dose of 200 mg/kg had a 12- to 14-min latency to onset and significantly reduced behavioral activity for 3 hr. Mice injected with 400 mg/kg exhibited locomotor deficits within 8-10 min and were affected for up to 9 hr. The ED50 for horizontal and vertical activities at 1 hr postinjection were determined to be 271 and 105 mg/kg, respectively. The results demonstrate that significant reductions in locomotor activity are exhibited at doses of 200 mg/kg or more and that vertical activity was more sensitive to the disruptive effects of WR-2721 than was horizontal activity

Effects of lipopolysaccharide and interleukin-6 on cataleptic immobility and locomotor activity in mice.

Science.gov (United States)

Bazovkina, Daria V; Tibeikina, Marina A; Kulikov, Alexander V; Popova, Nina K

2011-01-10

Catalepsy (animal hypnosis, tonic immobility) is a type of passive defensive behavior. Its exaggerated form is a syndrome of some psychopathological disorders. Numerous neurotransmitters have impact on the regulation of catalepsy. In this paper we demonstrated the involvement of interleukin-6 (IL-6) in the mechanism of cataleptic immobility. Effects of exogenous IL-6 treatment (7.5 and 10μg/kg, i.p) or stimulation of endogenous IL-6 secretion with lipopolysaccharide (LPS) administration (50, 100 and 200μg/kg, i.p.) on catalepsy and locomotor activity were studied in adult C57BL/6 male mice. IL-6 induced catalepsy in 70% (7.5μg/kg) or 72.7% (10μg/kg) of animals with no effect on locomotor activity. LPS administration reduced distance travelled and number of rears in the open field at any dose used, however, only high doses (100 or 200μg/kg) of the toxin induced catalepsy in 50% of mice. This result indicates that IL-6 is involved in the regulation of catalepsy, this effect is specific and does not arise from inhibition of locomotor activity. The study provides a new evidence on participation of IL-6 in mechanisms of abnormal behavior. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Evolving Capabilities for Virtual Globes

Science.gov (United States)

Glennon, A.

2006-12-01

Though thin-client spatial visualization software like Google Earth and NASA World Wind enjoy widespread popularity, a common criticism is their general lack of analytical functionality. This concern, however, is rapidly being addressed; standard and advanced geographic information system (GIS) capabilities are being developed for virtual globes--though not centralized into a single implementation or software package. The innovation is mostly originating from the user community. Three such capabilities relevant to the earth science, education, and emergency management communities are modeling dynamic spatial phenomena, real-time data collection and visualization, and multi-input collaborative databases. Modeling dynamic spatial phenomena has been facilitated through joining virtual globe geometry definitions--like KML--to relational databases. Real-time data collection uses short scripts to transform user-contributed data into a format usable by virtual globe software. Similarly, collaborative data collection for virtual globes has become possible by dynamically referencing online, multi-person spreadsheets. Examples of these functions include mapping flows within a karst watershed, real-time disaster assessment and visualization, and a collaborative geyser eruption spatial decision support system. Virtual globe applications will continue to evolve further analytical capabilities, more temporal data handling, and from nano to intergalactic scales. This progression opens education and research avenues in all scientific disciplines.

Increased amphetamine-induced locomotor activity, sensitization, and accumbal dopamine release in M5 muscarinic receptor knockout mice

DEFF Research Database (Denmark)

Schmidt, Lene S; Miller, Anthony D; Lester, Deranda B

2010-01-01

showed that M(5) receptor knockout (M (5) (-/-) ) mice are less sensitive to the reinforcing properties of addictive drugs. MATERIALS AND METHODS: Here, we investigate the role of M(5) receptors in the effects of amphetamine and cocaine on locomotor activity, locomotor sensitization, and dopamine release......-induced hyperactivity and dopamine release as well as amphetamine sensitization are enhanced in mice lacking the M(5) receptor. These results support the concept that the M(5) receptor modulates effects of addictive drugs....

Virus-mediated shRNA knockdown of prodynorphin in the rat nucleus accumbens attenuates depression-like behavior and cocaine locomotor sensitization.

Science.gov (United States)

Cohen, Ami; Whitfield, Timothy W; Kreifeldt, Max; Koebel, Pascale; Kieffer, Brigitte L; Contet, Candice; George, Olivier; Koob, George F

2014-01-01

Dynorphins, endogenous opioid peptides that arise from the precursor protein prodynorphin (Pdyn), are hypothesized to be involved in the regulation of mood states and the neuroplasticity associated with addiction. The current study tested the hypothesis that dynorphin in the nucleus accumbens (NAcc) mediates such effects. More specifically, we examined whether knockdown of Pdyn within the NAcc in rats would alter the expression of depressive-like and anxiety-like behavior, as well as cocaine locomotor sensitization. Wistar rats were injected with adeno-associated viral (AAV) vectors encoding either a Pdyn-specific short hairpin RNA (AAV-shPdyn) or a scrambled shRNA (AAV-shScr) as control. Four weeks later, rats were tested for anxiety-like behavior in the elevated plus maze test and depressive-like behavior in the forced swim test (FST). Finally, rats received one daily injection of saline or cocaine (20 mg/kg, i.p.), followed by assessment of locomotion for 4 consecutive days. Following 3 days of abstinence, the rats completed 2 additional daily cocaine/saline locomotor trials. Pdyn knockdown in the NAcc led to a significant reduction in depressive-like behavior in the FST, but had no effect on anxiety-like behavior in the elevated plus maze. Pdyn knockdown did not alter baseline locomotor behavior, the locomotor response to acute cocaine, or the initial sensitization of the locomotor response to cocaine over the first 4 cocaine treatment days. However, following 3 days abstinence the locomotor response to the cocaine challenge returned to their original levels in the AAV-shPdyn rats while remaining heightened in the AAV-shScr rats. These results suggest that dynorphin in a very specific area of the nucleus accumbens contributes to depressive-like states and may be involved in neuroadaptations in the NAcc that contribute to the development of cocaine addiction as a persistent and lasting condition.

Virus-mediated shRNA knockdown of prodynorphin in the rat nucleus accumbens attenuates depression-like behavior and cocaine locomotor sensitization.

Directory of Open Access Journals (Sweden)

Ami Cohen

Full Text Available Dynorphins, endogenous opioid peptides that arise from the precursor protein prodynorphin (Pdyn, are hypothesized to be involved in the regulation of mood states and the neuroplasticity associated with addiction. The current study tested the hypothesis that dynorphin in the nucleus accumbens (NAcc mediates such effects. More specifically, we examined whether knockdown of Pdyn within the NAcc in rats would alter the expression of depressive-like and anxiety-like behavior, as well as cocaine locomotor sensitization. Wistar rats were injected with adeno-associated viral (AAV vectors encoding either a Pdyn-specific short hairpin RNA (AAV-shPdyn or a scrambled shRNA (AAV-shScr as control. Four weeks later, rats were tested for anxiety-like behavior in the elevated plus maze test and depressive-like behavior in the forced swim test (FST. Finally, rats received one daily injection of saline or cocaine (20 mg/kg, i.p., followed by assessment of locomotion for 4 consecutive days. Following 3 days of abstinence, the rats completed 2 additional daily cocaine/saline locomotor trials. Pdyn knockdown in the NAcc led to a significant reduction in depressive-like behavior in the FST, but had no effect on anxiety-like behavior in the elevated plus maze. Pdyn knockdown did not alter baseline locomotor behavior, the locomotor response to acute cocaine, or the initial sensitization of the locomotor response to cocaine over the first 4 cocaine treatment days. However, following 3 days abstinence the locomotor response to the cocaine challenge returned to their original levels in the AAV-shPdyn rats while remaining heightened in the AAV-shScr rats. These results suggest that dynorphin in a very specific area of the nucleus accumbens contributes to depressive-like states and may be involved in neuroadaptations in the NAcc that contribute to the development of cocaine addiction as a persistent and lasting condition.

Physiological Costs of Repetitive Courtship Displays in Cockroaches Handicap Locomotor Performance

Science.gov (United States)

Mowles, Sophie L.; Jepson, Natalie M.

2015-01-01

Courtship displays are typically thought to have evolved via female choice, whereby females select mates based on the characteristics of a display that is expected to honestly reflect some aspect of the male’s quality. Honesty is typically enforced by mechanistic costs and constraints that limit the level at which a display can be performed. It is becoming increasingly apparent that these costs may be energetic costs involved in the production of dynamic, often repetitive displays. A female attending to such a display may thus be assessing the physical fitness of a male as an index of his quality. Such assessment would provide information on his current physical quality as well as his ability to carry out other demanding activities, qualities with which a choosy female should want to provision her offspring. In the current study we use courtship interactions in the Cuban burrowing cockroach, Byrsotria fumigata to directly test whether courtship is associated with a signaler’s performance capacity. Males that had produced courtship displays achieved significantly lower speeds and distances in locomotor trials than non-courting control males. We also found that females mated more readily with males that produced a more vigorous display. Thus, males of this species have developed a strategy where they produce a demanding courtship display, while females choose males based on their ability to produce this display. Courtship displays in many taxa often involve dynamic repetitive actions and as such, signals of stamina in courtship may be more widespread than previously thought. PMID:26606147

Speed-Dependent Modulation of the Locomotor Behavior in Adult Mice Reveals Attractor and Transitional Gaits.

Science.gov (United States)

Lemieux, Maxime; Josset, Nicolas; Roussel, Marie; Couraud, Sébastien; Bretzner, Frédéric

2016-01-01

Locomotion results from an interplay between biomechanical constraints of the muscles attached to the skeleton and the neuronal circuits controlling and coordinating muscle activities. Quadrupeds exhibit a wide range of locomotor gaits. Given our advances in the genetic identification of spinal and supraspinal circuits important to locomotion in the mouse, it is now important to get a better understanding of the full repertoire of gaits in the freely walking mouse. To assess this range, young adult C57BL/6J mice were trained to walk and run on a treadmill at different locomotor speeds. Instead of using the classical paradigm defining gaits according to their footfall pattern, we combined the inter-limb coupling and the duty cycle of the stance phase, thus identifying several types of gaits: lateral walk, trot, out-of-phase walk, rotary gallop, transverse gallop, hop, half-bound, and full-bound. Out-of-phase walk, trot, and full-bound were robust and appeared to function as attractor gaits (i.e., a state to which the network flows and stabilizes) at low, intermediate, and high speeds respectively. In contrast, lateral walk, hop, transverse gallop, rotary gallop, and half-bound were more transient and therefore considered transitional gaits (i.e., a labile state of the network from which it flows to the attractor state). Surprisingly, lateral walk was less frequently observed. Using graph analysis, we demonstrated that transitions between gaits were predictable, not random. In summary, the wild-type mouse exhibits a wider repertoire of locomotor gaits than expected. Future locomotor studies should benefit from this paradigm in assessing transgenic mice or wild-type mice with neurotraumatic injury or neurodegenerative disease affecting gait.

[Application of locomotor activity test to evaluate functional injury after global cerebral ischemia in C57BL/6 mice].

Science.gov (United States)

Zhang, Li-quan; Xu, Jia-ni; Wang, Zhen-zhen; Zeng, Li-jun; Ye, Yi-lu; Zhang, Wei-ping; Wei, Er-qing; Zhang, Qi

2014-05-01

To evaluate the application of locomotor activity test in functional injury after global cerebral ischemia (GCI) in C57BL/6 mice. GCI was induced by bilateral carotid arteries occlusion for 30 min in C57BL/6 mice. Mice were divided into sham group, GCI group and minocycline group. Saline or minocycline (45 mg/kg) was i.p. injected once daily for 6 d after ischemia. At Day 6 after ischemia, locomotor activity was recorded for 1 h in open field test. Total distance, central distance, central distance ratio, periphery distance, periphery distance ratio, central time and periphery time were used to evaluate the behavior characteristics of locomotor activity in C57BL/6 mice after ischemia. The survival neuron density was detected by Nissl staining in hippocampus, cortex and striatum. Compared with sham group, total distance, central distance and central time increased and periphery time decreased in C57BL/6 mice after GCI (PsLocomotor activity in open field test can objectively evaluate the behavior injury after GCI in mice. Central distance and central time can be used as indexes of quantitative assessment.

Motor hypertonia and lack of locomotor coordination in mutant mice lacking DSCAM.

Science.gov (United States)

Lemieux, Maxime; Laflamme, Olivier D; Thiry, Louise; Boulanger-Piette, Antoine; Frenette, Jérôme; Bretzner, Frédéric

2016-03-01

Down syndrome cell adherence molecule (DSCAM) contributes to the normal establishment and maintenance of neural circuits. Whereas there is abundant literature regarding the role of DSCAM in the neural patterning of the mammalian retina, less is known about motor circuits. Recently, DSCAM mutation has been shown to impair bilateral motor coordination during respiration, thus causing death at birth. DSCAM mutants that survive through adulthood display a lack of locomotor endurance and coordination in the rotarod test, thus suggesting that the DSCAM mutation impairs motor control. We investigated the motor and locomotor functions of DSCAM(2J) mutant mice through a combination of anatomical, kinematic, force, and electromyographic recordings. With respect to wild-type mice, DSCAM(2J) mice displayed a longer swing phase with a limb hyperflexion at the expense of a shorter stance phase during locomotion. Furthermore, electromyographic activity in the flexor and extensor muscles was increased and coactivated over 20% of the step cycle over a wide range of walking speeds. In contrast to wild-type mice, which used lateral walk and trot at walking speed, DSCAM(2J) mice used preferentially less coordinated gaits, such as out-of-phase walk and pace. The neuromuscular junction and the contractile properties of muscles, as well as their muscle spindles, were normal, and no signs of motor rigidity or spasticity were observed during passive limb movements. Our study demonstrates that the DSCAM mutation induces dystonic hypertonia and a disruption of locomotor gaits. Copyright © 2016 the American Physiological Society.

The effects of opioid drugs on dopamine mediated locomotor activity in rats

International Nuclear Information System (INIS)

Leathern, L.L.

1986-12-01

Opioid drugs influence various behavioural parameters including locomotor activity in experimental animals. The interaction between the opioid and dopaminergic systems is one possible explanation for the effect of opioid drugs on locomotor activity. In this study behavioural and biochemical assays were done to investigate the interaction between the opioid and dopaminergic systems. Behavioural studies were done by measurement of locomotor activity (LA) of rats after acute or chronic pretreatment with opioid and/or dopaminergic drugs. Biochemical studies were in the form of radioligand binding assays, the effect on the number (Bmax) and affinity (K D ) of receptors was measured after chronic pretreatment with opioid and/or dopaminergic drugs. The opioid drugs used are morphine, nalbuphine and naloxone. Dopaminergic drugs used included: agonists-apomorphine and piribedil; antagonists-pimozide, haloperidol, chlorpromazine. In the acute situation increased LA was obtained with morphine and the DA agonists. A correlation between the behavioural and biochemical assays was found. Chronic pretreatment with morphine enhanced apomorphine induced LA, this supersensitivity was also measured as an increased receptor density (Bmax) of D2 receptors in the striatum. Chronic morphine pretreatment caused a decrease in morphine induced LA, while this subsensitivity was not apparent in the ligand binding assays - where no change in receptor number was observed. Chronic naloxone pretreatment enhanced morphine induced LA, as well as increased the Bmax of opioid receptors in the whole brain. It is concluded that an interaction between the opioid and dopaminergic systems does exist, and may account for the mechanism of action of the opioids

The influence of an innovative locomotor strategy on the phenotypic diversification of triggerfish (family: Balistidae).

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Dornburg, Alex; Sidlauskas, Brian; Santini, Francesco; Sorenson, Laurie; Near, Thomas J; Alfaro, Michael E

2011-07-01

Innovations in locomotor morphology have been invoked as important drivers of vertebrate diversification, although the influence of novel locomotion strategies on marine fish diversification remains largely unexplored. Using triggerfish as a case study, we determine whether the evolution of the distinctive synchronization of enlarged dorsal and anal fins that triggerfish use to swim may have catalyzed the ecological diversification of the group. By adopting a comparative phylogenetic approach to quantify median fin and body shape integration and to assess the tempo of functional and morphological evolution in locomotor traits, we find that: (1) functional and morphological components of the locomotive system exhibit a strong signal of correlated evolution; (2) triggerfish partitioned locomotor morphological and functional spaces early in their history; and (3) there is no strong evidence that a pulse of lineage diversification accompanied the major episode of phenotypic diversification. Together these findings suggest that the acquisition of a distinctive mode of locomotion drove an early radiation of shape and function in triggerfish, but not an early radiation of species. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Development of sensory system s related with postural - locomotor function in toddler ́s age, possibilities of assessmen

OpenAIRE

Blažková, Markéta

2014-01-01

Bachelor's thesis "Development of sensory systems related with postural-locomotor function in toddler's age, possibilities of assessment" summarizes function of visual, vestibular and somatosensory system and maturation of these systems in toddler's age. Next part describes the development of postural- locomotor function related to maturation of sensory systems. The last part of the work deals with the issue of assessment in toddler's age. Three toddlers are described in the practical part of...

Voluntary locomotor activity mitigates oxidative damage associated with isolation stress in the prairie vole (Microtus ochrogaster).

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Fletcher, Kelsey L; Whitley, Brittany N; Treidel, Lisa A; Thompson, David; Williams, Annie; Noguera, Jose C; Stevenson, Jennie R; Haussmann, Mark F

2015-07-01

Organismal performance directly depends on an individual's ability to cope with a wide array of physiological challenges. For social animals, social isolation is a stressor that has been shown to increase oxidative stress. Another physiological challenge, routine locomotor activity, has been found to decrease oxidative stress levels. Because we currently do not have a good understanding of how diverse physiological systems like stress and locomotion interact to affect oxidative balance, we studied this interaction in the prairie vole (Microtus ochrogaster). Voles were either pair housed or isolated and within the isolation group, voles either had access to a moving wheel or a stationary wheel. We found that chronic periodic isolation caused increased levels of oxidative stress. However, within the vole group that was able to run voluntarily, longer durations of locomotor activity were associated with less oxidative stress. Our work suggests that individuals who demonstrate increased locomotor activity may be better able to cope with the social stressor of isolation. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Drugs that Target Dopamine Receptors: Changes in Locomotor Activity in Larval Zebrafish

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As part of an effort at the US Environmental Protection Agency to develop a rapid in vivo screen for prioritization of toxic chemicals, we have begun to characterize the locomotor activity of zebrafish (Danio rerio) larvae. This includes assessing the acute effects of drugs known...

Designing Functional Clothes for Persons with Locomotor Disabilities

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Curteza Antonela

2014-12-01

Full Text Available The life quality improvement issue is a problem of national and international interest. This acquires total different values when it is to refer to a series of disadvantaged categories, that is the persons with locomotor disabilities. It is an inevitable social responsibility to create equal opportunities for disabled people, to prevent any intentional or unintentional discrimination that they face and apply positive discrimination if necessary to improve their living standards and to let them have an equal share from social development as productive individuals of society.

Effect of injection of antisense oligodeoxynucleotides of GAD isozymes into rat ventromedial hypothalamus on food intake and locomotor activity.

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Bannai, M; Ichikawa, M; Nishihara, M; Takahashi, M

1998-02-16

In the ventromedial hypothalamus (VMH), gamma-aminobutyric acid (GABA) plays a role in regulating feeding and running behaviors. The GABA synthetic enzyme, glutamic acid decarboxylase (GAD), consists of two isozymes, GAD65 and GAD67. In the present study, the phosphorothioated antisense oligodeoxynucleotides (ODNs) of each GAD isozyme were injected bilaterally into the VMH of male rats, and food intake, body weight and locomotor activity were monitored. ODNs were incorporated in the water-absorbent polymer (WAP, 0.2 nmol/microliter) so that ODNs were retained at the injection site. Each antisense ODN of GAD65 or GAD67 tended to reduce food intake on day 1 (day of injection=day 0) though not significantly. An injection combining both antisense ODNs significantly decreased food intake only on day 1, but body weight remained significantly lower than the control for 5 days. This suppression of body weight gain could be attributed to a significant increase in locomotor activity between days 3 and 5. Individual treatment with either ODNs did not change locomotor activity. The increase in daily locomotor activity in the group receiving the combined antisense ODNs occurred mainly during the light phase. Neither vehicle (WAP) nor control ODN affected food intake, body weight and locomotor activity. Histological studies indicated that antisense ODN distributed within 800 micron from the edge of the area where WAP was located 24 h after the injection gradually disappeared within days, but still remained within 300 micron m distance even 7 days after the injection. Antisense ODN was effectively incorporated by all the cell types examined, i.e., neurons, astrocytes and microglias. Further, HPLC analysis revealed that antisense ODNs of GAD isozymes, either alone or combined, decreased the content of GABA by 50% in VMH 24 h after the injection. These results indicate that suppression of GABA synthesis by either of the GAD isozymes is synergistically involved in suppressing food

Agomelatine's effect on circadian locomotor rhythm alteration and depressive-like behavior in 6-OHDA lesioned rats.

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Souza, Leonardo C; Martynhak, Bruno J; Bassani, Taysa B; Turnes, Joelle de M; Machado, Meira M; Moura, Eric; Andreatini, Roberto; Vital, Maria A B F

2018-05-01

Parkinson's disease (PD) patients often suffer from circadian locomotor rhythms impairment and depression, important non-motor symptoms. It is known that toxin-based animal models of PD can reproduce these features. In a 6-hydroxydopamine (6-OHDA) intranigral model, we first investigated the possible disturbances on circadian rhythms of locomotor activity. The rats were divided into 6-OHDA and Sham groups. After a partial dopaminergic lesion, the 6-OHDA group showed slight alterations in different circadian locomotor rhythms parameters. In a second experiment, we hypothesized agomelatine, an melatoninergic antidepressant with potential to resynchronize disturbed rhythms, could prevent neuronal damage and rhythm alterations in the same 6-OHDA model. The animals were divided into four groups: 6-OHDA+vehicle, 6-OHDA+ago, Sham+vehicle and 6-OHDA+ago. However, the treated animals (agomelatine 50 mg/kg for 22 days) showed an impaired rhythm robustness, and agomelatine did not induce significant changes in the other circadian parameters nor neuroprotection. Finally, in a third experiment, we examined the effects of agomelatine in the 6-OHDA model regarding depressive-like behavior, evaluated by sucrose preference test. The animals were also divided into four groups: 6-OHDA+vehicle, 6-OHDA+ago, Sham+vehicle and 6-OHDA+ago. The toxin infused animals showed a decrease in sucrose preference in comparison with the vehicle infused animals, however, agomelatine did not prevent this decrease. Our findings indicate that agomelatine worsened circadian locomotor rhythm and was not able to reverse the depressive-like behavior of rats in the 6-OHDA PD model. Copyright © 2018. Published by Elsevier Inc.

NO INFLUENCE OF HYPOXIA ON COORDINATION BETWEEN RESPIRATORY AND LOCOMOTOR RHYTHMS DURING ROWING AT MODERATE INTENSITY

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Nicolas Fabre

2007-12-01

Full Text Available Besides neuro-mechanical constraints, chemical or metabolic stimuli have also been proposed to interfere with the coordination between respiratory and locomotor rhythms. In the light of the conflicting data observed in the literature, this study aimed to assess whether acute hypoxia modifies the degree of coordination between respiratory and locomotor rhythms during rowing exercises in order to investigate competitive interactions between neuro-mechanical (movement and chemical (hypoxia respiratory drives. Nine male healthy subjects performed one submaximal 6-min rowing exercise on a rowing ergometer in both normoxia (altitude: 304 m and acute hypoxia (altitude: 2877 m. The exercise intensity was about 40 % and 35 % (for normoxia and hypoxia conditions, respectively of the individual maximal power output measured during an incremental rowing test to volitional exhaustion carried out in normoxia. Metabolic rate and minute ventilation were continuously collected throughout exercise. Locomotor movement and breathing rhythms were continuously recorded and synchronized cycle-by-cycle. The degree of coordination was expressed as a percentage of breaths starting during the same phase of the locomotor cycle. For a same and a constant metabolic rate, acute hypoxia did not influence significantly the degree of coordination (mean ± SEM, normoxia: 20.0 ± 6.2 %, hypoxia: 21.3 ± 11.1 %, p > 0.05 while ventilation and breathing frequency were significantly greater in hypoxia. Our results may suggest that during rowing exercise at a moderate metabolic load, neuro-mechanical locomotion-linked respiratory stimuli appear "stronger" than peripheral chemoreceptors- linked respiratory stimuli induced by hypoxia, in the context of our study

The Application of Dynamic Capabilities in E-commerce Innovation Context : The Implications for Chinese E-commerce companies

OpenAIRE

Chen, YongJia; Liang, WeiMin

2007-01-01

This study mainly investigated how Chinese E-commerce companies should cope with E-commerce innovation with specific dynamic capabilities. E-commerce (Electronic Commerce) innovation includes three phases of innovation based on technology and time. They are web-based commerce, mobile commerce (M-commerce) and ubiquitous commerce (U-commerce). They caused not only technological changes but also organizational changes. To cope with E-commerce innovation, a prerequisite is to understand the impa...

Analysis of Indonesian Spice Essential Oil Compounds That Inhibit Locomotor Activity in Mice

Science.gov (United States)

Muchtaridi; Diantini, Adjeng; Subarnas, Anas

2011-01-01

Some fragrance components of spices used for cooking are known to have an effect on human behavior. The aim of this investigation was to examine the effect of the essential oils of basil (Ocimum formacitratum L.) leaves, lemongrass (Cymbopogon citrates L.) herbs, ki lemo (Litsea cubeba L.) bark, and laja gowah (Alpinia malaccencis Roxb.) rhizomes on locomotor activity in mice and identify the active component(s) that might be responsible for the activity. The effect of the essential oils was studied by a wheel cage method and the active compounds of the essential oils were identified by GC/MS analysis. The essential oils were administered by inhalation at doses of 0.1, 0.3, and 0.5 mL/cage. The results showed that the four essential oils had inhibitory effects on locomotor activity in mice. Inhalation of the essential oils of basil leaves, lemongrass herbs, ki lemo bark, and laja gowah rhizomes showed the highest inhibitory activity at doses of 0.5 (57.64%), 0.1 (55.72%), 0.5 (60.75%), and 0.1 mL/cage (47.09%), respectively. The major volatile compounds 1,8-cineole, α-terpineol, 4-terpineol, citronelol, citronelal, and methyl cinnamate were identified in blood plasma of mice after inhalation of the four oils. These compounds had a significant inhibitory effect on locomotion after inhalation. The volatile compounds of essential oils identified in the blood plasma may correlate with the locomotor-inhibiting properties of the oil when administered by inhalation.

A disparity between locomotor economy and territory-holding ability in male house mice.

Science.gov (United States)

Morris, Jeremy S; Ruff, James S; Potts, Wayne K; Carrier, David R

2017-07-15

Both economical locomotion and physical fighting are important performance traits to many species because of their direct influence on components of Darwinian fitness. Locomotion represents a substantial portion of the total daily energy budget of many animals. Fighting performance often determines individual reproductive fitness through the means of resource control, social dominance and access to mates. However, phenotypic traits that improve either locomotor economy or fighting ability may diminish performance in the other. Here, we tested for a predicted disparity between locomotor economy and competitive ability in wild-derived house mice ( Mus musculus ). We used 8 week social competition trials in semi-natural enclosures to directly measure male competitive ability through territorial control and female occupancy within territories. We also measured oxygen consumption during locomotion for each mouse using running trials in an enclosed treadmill and open-flow respirometry. Our results show that territory-holding males have higher absolute and mass-specific oxygen consumption when running (i.e. reduced locomotor economy) compared with males that do not control territories. This relationship was present both before and after 8 week competition trials in semi-natural enclosures. This disparity between physical competitive ability and economical locomotion may impose viability costs on males in species for which competition over mates is common and may constrain the evolution of behavioral and phenotypic diversity, particularly in natural settings with environmental and resource variability. © 2017. Published by The Company of Biologists Ltd.

Digestive and locomotor capacity show opposing responses to changing food availability in an ambush predatory fish.

Science.gov (United States)

Fu, Shi-Jian; Peng, Jing; Killen, Shaun S

2018-06-14

Metabolic rates vary widely within species, but little is known about how variation in the 'floor' [i.e. standard metabolic rate (SMR) in ectotherms] and 'ceiling' [maximum metabolic rate (MMR)] for an individual's aerobic scope (AS) are linked with digestive and locomotor function. Any links among metabolic traits and aspects of physiological performance may also be modulated by fluctuations in food availability. This study followed changes in SMR, MMR, and digestive and locomotor capacity in southern catfish ( Silurus meridionalis ) throughout 15 days of food deprivation and 15 days of refeeding. Individuals downregulated SMR during food deprivation and showed only a 10% body mass decrease during this time. Whereas critical swim speed ( U crit ) was robust to food deprivation, digestive function decreased after fasting with a reduced peak oxygen uptake during specific dynamic action (SDA) and prolonged SDA duration. During refeeding, individuals displayed rapid growth and digestive function recovered to pre-fasting levels. However, refed fish showed a lower U crit than would be expected for their increased body length and in comparison to measures at the start of the study. Reduced swimming ability may be a consequence of compensatory growth: growth rate was negatively correlated with changes in U crit during refeeding. Southern catfish downregulate digestive function to reduce energy expenditure during food deprivation, but regain digestive capacity during refeeding, potentially at the cost of decreased swimming performance. The plasticity of maintenance requirements suggests that SMR is a key fitness trait for in this ambush predator. Shifts in trait correlations with food availability suggest that the potential for correlated selection may depend on context. © 2018. Published by The Company of Biologists Ltd.

Balance and ambulation improvements in individuals with chronic incomplete spinal cord injury using locomotor training-based rehabilitation.

Science.gov (United States)

Harkema, Susan J; Schmidt-Read, Mary; Lorenz, Douglas J; Edgerton, V Reggie; Behrman, Andrea L

2012-09-01

To evaluate the effects of intensive locomotor training on balance and ambulatory function at enrollment and discharge during outpatient rehabilitation after incomplete SCI. Prospective observational cohort. Seven outpatient rehabilitation centers from the Christopher and Dana Reeve Foundation NeuroRecovery Network (NRN). Patients (N=196) with American Spinal Injury Association Impairment Scale (AIS) grade C or D SCI who received at least 20 locomotor training treatment sessions in the NRN. Intensive locomotor training, including step training using body-weight support and manual facilitation on a treadmill followed by overground assessment and community integration. Berg Balance Scale; Six-Minute Walk Test; 10-Meter Walk Test. Outcome measures at enrollment showed high variability between patients with AIS grades C and D. Significant improvement from enrollment to final evaluation was observed in balance and walking measures for patients with AIS grades C and D. The magnitude of improvement significantly differed between AIS groups for all measures. Time since SCI was not associated significantly with outcome measures at enrollment, but was related inversely to levels of improvement. Significant variability in baseline values of functional outcome measures is evident after SCI in individuals with AIS grades C and D and significant functional recovery can continue to occur even years after injury when provided with locomotor training. These results indicate that rehabilitation, which provides intensive activity-based therapy, can result in functional improvements in individuals with chronic incomplete SCI. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

NEW GROWTH PLATFORM FRAMEWORK FOR SWISS ACUTE HOSPITALS - AN EMPIRICAL STUDY FOR THE DEVELOPMENT OF DYNAMIC CAPABILITIES

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Zoran Alimpic

2013-11-01

Full Text Available Swiss health care is confronted with fundamental changes. On the one hand, there are increasing costs in patient treatments, caused by innovative technology with new high-capacity medical devices, and a lack of effectiveness and efficiency in the organisation of a hospital. On the other hand, hospitals do have decreasing revenues with the introduction of the new patient classification and tariff system DRG (Diagnosis Related Groups by 2012. For every DRG, hospitals will receive a fixed price, separate from the actual costs of the patient treatment. In this paper it was explored the case of 13 successful Swiss private acute hospitals which are also confronted with these pressures to reduce their costs of patient treatment and therefore to optimise their processes of care. This research focuses on dynamic capabilitie of the hospitals. Although dynamic capabilities are idiosyncratic in their details and path dependent in their emergence, they have significant ‘best practise’ across firms (Eisenhardt and Martin, 2000. The research is started with the evaluation of new trends, key customers’ needs, and capabilities, with questionnaires for attending physicians and hospital managers. The NGP approach gives hospital managers the enough crucial information for a strategy formulation in fundamental changing environments, which is the key contribution of this manuscript.

The effects of the novel DA D3 receptor antagonist SR 21502 on cocaine reward, cocaine seeking and cocaine-induced locomotor activity in rats.

Science.gov (United States)

Galaj, E; Ananthan, S; Saliba, M; Ranaldi, Robert

2014-02-01

There is a focus on developing D3 receptor antagonists as cocaine addiction treatments. We investigated the effects of a novel selective D3 receptor antagonist, SR 21502, on cocaine reward, cocaine-seeking, food reward, spontaneous locomotor activity and cocaine-induced locomotor activity in rats. In Experiment 1, rats were trained to self-administer cocaine under a progressive ratio (PR) schedule of reinforcement and tested with vehicle or one of three doses of SR 21502. In Experiment 2, animals were trained to self-administer cocaine under a fixed ratio schedule of reinforcement followed by extinction of the response. Then, animals were tested with vehicle or one of the SR 21502 doses on cue-induced reinstatement of responding. In Experiment 3, animals were trained to lever press for food under a PR schedule and tested with vehicle or one dose of the compound. In Experiments 4 and 5, in separate groups of animals, the vehicle and three doses of SR 21502 were tested on spontaneous or cocaine (10 mg/kg, IP)-induced locomotor activity, respectively. SR 21502 produced significant, dose-related (3.75, 7.5 and 15 mg/kg) reductions in breakpoint for cocaine self-administration, cue-induced reinstatement (3.75, 7.5 and 15 mg/kg) and cocaine-induced locomotor activity (3.75, 7.5 and 15 mg/kg) but failed to reduce food self-administration and spontaneous locomotor activity. SR 21502 decreases cocaine reward, cocaine-seeking and locomotor activity at doses that have no effect on food reward or spontaneous locomotor activity. These data suggest SR 21502 may selectively inhibit cocaine's rewarding, incentive motivational and stimulant effects.

An Intensive Locomotor Training Paradigm Improves Neuropathic Pain following Spinal Cord Compression Injury in Rats.

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Dugan, Elizabeth A; Sagen, Jacqueline

2015-05-01

Spinal cord injury (SCI) is often associated with both locomotor deficits and sensory dysfunction, including debilitating neuropathic pain. Unfortunately, current conventional pharmacological, physiological, or psychological treatments provide only marginal relief for more than two-thirds of patients, highlighting the need for improved treatment options. Locomotor training is often prescribed as an adjunct therapy for peripheral neuropathic pain but is rarely used to treat central neuropathic pain. The goal of this study was to evaluate the potential anti-nociceptive benefits of intensive locomotor training (ILT) on neuropathic pain consequent to traumatic SCI. Using a rodent SCI model for central neuropathic pain, ILT was initiated either 5 d after injury prior to development of neuropathic pain symptoms (the "prevention" group) or delayed until pain symptoms fully developed (∼3 weeks post-injury, the "reversal" group). The training protocol consisted of 5 d/week of a ramping protocol that started with 11 m/min for 5 min and increased in speed (+1 m/min/week) and time (1-4 minutes/week) to a maximum of two 20-min sessions/d at 15 m/min by the fourth week of training. ILT prevented and reversed the development of heat hyperalgesia and cold allodynia, as well as reversed developed tactile allodynia, suggesting analgesic benefits not seen with moderate levels of locomotor training. Further, the analgesic benefits of ILT persisted for several weeks once training had been stopped. The unique ability of an ILT protocol to produce robust and sustained anti-nociceptive effects, as assessed by three distinct outcome measures for below-level SCI neuropathic pain, suggests that this adjunct therapeutic approach has great promise in a comprehensive treatment strategy for SCI pain.

Syngeneic B16F10 Melanoma Causes Cachexia and Impaired Skeletal Muscle Strength and Locomotor Activity in Mice

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Fabrício A. Voltarelli

2017-09-01

Full Text Available Muscle wasting has been emerging as one of the principal components of cancer cachexia, leading to progressive impairment of work capacity. Despite early stages melanomas rarely promotes weight loss, the appearance of metastatic and/or solid tumor melanoma can leads to cachexia development. Here, we investigated the B16F10 tumor-induced cachexia and its contribution to muscle strength and locomotor-like activity impairment. C57BL/6 mice were subcutaneously injected with 5 × 104 B16F10 melanoma cells or PBS as a Sham negative control. Tumor growth was monitored during a period of 28 days. Compared to Sham mice, tumor group depicts a loss of skeletal muscle, as well as significantly reduced muscle grip strength and epididymal fat mass. This data are in agreement with mild to severe catabolic host response promoted by elevated serum tumor necrosis factor-alpha (TNF-α, interleukin-6 (IL-6 and lactate dehydrogenase (LDH activity. Tumor implantation has also compromised general locomotor activity and decreased exploratory behavior. Likewise, muscle loss, and elevated inflammatory interleukin were associated to muscle strength loss and locomotor activity impairment. In conclusion, our data demonstrated that subcutaneous B16F10 melanoma tumor-driven catabolic state in response to a pro-inflammatory environment that is associated with impaired skeletal muscle strength and decreased locomotor activity in tumor-bearing mice.

Exploring the impact of dynamic capabilities on sustainable supply chain firm's performance using Grey-Analytical Hierarchy Process

DEFF Research Database (Denmark)

Govindan, Kannan; Mathivathanan, Deepak; Haq, A. Noorul

2017-01-01

Dynamic capabilities (DCs) are the inherent capabilities developed by firms through the implementation of Sustainable Supply Chain practices. These DCs serve as a backbone for the firms to achieve competitive advantages in contemporary ever-changing markets. The present study focuses on exploring...... industrial managers to identify specific influential DCs for each performance measure category by overcoming the limitations of few experts through the application of the grey multi criteria decision making system. Identifying and prioritizing performance-specific DCs allow sustainable supply chain oriented...... performance measures identified from the literature. First, through a questionnaire survey with industrial experts from south India as respondents, the initial list of 77 DCs is confined to a list of 40 essential DCs. Second, the shortlisted 40 DCs are grouped under six performance measures; a logical...

Effects of insemination and blood-feeding on locomotor activity of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) females under laboratory conditions.

Science.gov (United States)

Lima-Camara, Tamara Nunes; Lima, José Bento Pereira; Bruno, Rafaela Vieira; Peixoto, Alexandre Afranio

2014-07-02

Dengue is an arbovirus disease transmitted by two Aedes mosquitoes: Ae. aegypti and Ae. albopictus. Virgin females of these two species generally show a bimodal and diurnal pattern of activity, with early morning and late afternoon peaks. Although some studies on the flight activity of virgin, inseminated and blood-fed Ae. aegypti females have been carried out under laboratory conditions, little is known about the effects of such physiological states on the locomotor activity of Ae. albopictus and Ae. aegypti females. The aim of this study was to analyze, under laboratory conditions, the effects of insemination and blood-feeding on the locomotor activity of Ae. albopictus and Ae. aegypti females under LD 12:12, at 25°C. Both Ae. albopictus and Ae. aegypti females were obtained from established laboratory colonies. Control groups were represented by virgin/unfed Ae. albopictus and Ae. aegypti females. Experiments were conducted under laboratory conditions, using an activity monitor that registers individual activity every thirty minutes. Virgin/unfed Ae. albopictus and Ae. aegypti females showed a diurnal and bimodal pattern of locomotor activity, with peaks at early morning and late afternoon. Insemination and blood-feeding significantly decreased the locomotor activity of Ae. aegypti females, but inseminated/blood-fed Ae. aegypti and Ae. albopictus females showed a similar significant decrease on the locomotor activity compared to virgin/unfed females. This study is the first demonstration of the effects of insemination and blood-feeding on the locomotor activity of Ae. albopictus and Ae. aegypti females under artificial conditions. Data suggest that Ae. albopictus and Ae. aegypti females respond in different ways to physiological status changes and such divergence between these two dengue vectors, associated with several ecological differences, could be related to the greater dengue vectorial capacity of Ae. aegypti in Americas in comparison to Ae. albopictus.

Circadian Clock Protein Content and Daily Rhythm of Locomotor Activity Are Altered after Chronic Exposure to Lead in Rat

Science.gov (United States)

Sabbar, Mariam; Dkhissi-Benyahya, Ouria; Benazzouz, Abdelhamid; Lakhdar-Ghazal, Nouria

2017-01-01

Lead exposure has been reported to produce many clinical features, including parkinsonism. However, its consequences on the circadian rhythms are still unknown. Here we aimed to examine the circadian rhythms of locomotor activity following lead intoxication and investigate the mechanisms by which lead may induce alterations of circadian rhythms in rats. Male Wistar rats were injected with lead or sodium acetate (10 mg/kg/day, i.p.) during 4 weeks. Both groups were tested in the “open field” to quantify the exploratory activity and in the rotarod to evaluate motor coordination. Then, animals were submitted to continuous 24 h recordings of locomotor activity under 14/10 Light/dark (14/10 LD) cycle and in complete darkness (DD). At the end of experiments, the clock proteins BMAL1, PER1-2, and CRY1-2 were assayed in the suprachiasmatic nucleus (SCN) using immunohistochemistry. We showed that lead significantly reduced the number of crossing in the open field, impaired motor coordination and altered the daily locomotor activity rhythm. When the LD cycle was advanced by 6 h, both groups adjusted their daily locomotor activity to the new LD cycle with high onset variability in lead-intoxicated rats compared to controls. Lead also led to a decrease in the number of immunoreactive cells (ir-) of BMAL1, PER1, and PER2 without affecting the number of ir-CRY1 and ir-CRY2 cells in the SCN. Our data provide strong evidence that lead intoxication disturbs the rhythm of locomotor activity and alters clock proteins expression in the SCN. They contribute to the understanding of the mechanism by which lead induce circadian rhythms disturbances. PMID:28970786

The influence of company’s dynamic capabilities on achieving a competitive advantage as the new management paradigm

Directory of Open Access Journals (Sweden)

Ilona Penc-Pietrzak

2014-12-01

Full Text Available The paper presents the most important conceptions of achieving a company’s competitive advantage: Porter’s five forces model based on the SCP paradigm; the conception of strategic conflict, which uses the tools of game theory; resource-based perspective, which emphasizes the distinctive resources and skills of a company and the dynamic capabilities approach, which is very useful in turbulent environment. The last conception is correctly treated as the new management paradigm.

Conditioned Place Preference to Acetone Inhalation and the Effects on Locomotor Behavior and 18FDG Uptake

Energy Technology Data Exchange (ETDEWEB)

Pai, J.C.; Dewey, S.L.; Schiffer, W.; Lee, D.

2006-01-01

Acetone is a component in many inhalants that have been widely abused. While other solvents have addictive potential, such as toluene, it is unclear whether acetone alone contains addictive properties. The locomotor, relative glucose metabolism and abusive effects of acetone inhalation were studied in animals using the conditioned place preference (CPP) paradigm and [18F]2-fluorodeoxy-D-glucose (18FDG) imaging. The CPP apparatus contains two distinct conditioning chambers and a middle adaptation chamber, each lined with photocells to monitor locomotor activity. Adolescent Sprague-Dawley rats (n=16; 90-110 g) were paired with acetone in least preferred conditioning chamber, determined on the pretest day. The animals were exposed to a 10,000 ppm dose for an hour, alternating days with air. A CPP test was conducted after the 3rd, 6th and 12th pairing. In these same animals, the relative glucose metabolism effects were determined using positron emission tomography (PET) imaging with 18FDG. Following the 3rd pairing, there was a significant aversion to the acetone paired chamber (190.9 ± 13.7 sec and 241.7 ± 16.9 sec, acetone and air, respectively). After the 6th pairing, there was no significant preference observed with equal time spent in each chamber (222 ± 21 sec and 207 ± 20 sec, acetone and air-paired, respectively). A similar trend was observed after the 12th pairing (213 ± 21 sec and 221 ± 22 sec, acetone and air-paired, respectively). Locomotor analysis indicated a significant decrease (p<0.05) from air pairings to acetone pairings on the first and sixth pairings. The observed locomotor activity was characteristic of central nervous system (CNS) depressants, without showing clear abusive effects in this CPP model. In these studies, acetone vapors were not as reinforcing as other solvents, shown by overall lack of preference for the acetone paired side of the chamber. PET imaging indicated a regionally specific distribution of 18FDG uptake following

A rapid enhancement of locomotor sensitization to amphetamine by estradiol in female rats.

Science.gov (United States)

Zovkic, Iva B; McCormick, Cheryl M

2017-11-14

Estradiol moderates the effects of drugs of abuse in both humans and rodents. Estradiol's enhancement of behavioral effects resulting from high (>2.5mg/kg) doses of amphetamine is established in rats; there is less evidence for the role of estradiol in locomotor effects elicited by lower doses, which are less aversive, increase incentive motivation, involve different neural mechanisms than higher doses, and often more readily reveal group differences than do higher doses. Further, the extent to which estradiol is required for the induction versus the expression of sensitization is unknown. To establish a protocol, we replicated the effects of estradiol on locomotor sensitization to amphetamine reported in a previous study that involved a high locomotor-activating dose (1.5mg/kg) of amphetamine, but with a lower dose. Ovariectomized female rats received 5μg of estradiol benzoate (EB) or OIL 30min before each of 5 treatments of 1.0mg/kg amphetamine or saline; all received a 0.5mg/kg challenge dose three days later. Compared with results for OIL, EB enhanced the locomotor-activating effects of repeated 1.0mg/kg amphetamine across treatment days. In contrast, on challenge day, there was no difference between EB-saline and EB-amphetamine to the lower dose (i.e., no sensitization). Experiments 2 and 3 involved a shorter induction (2days) and a lengthier withdrawal (9days) before the challenge test for the expression of sensitization to better differentiate the induction phase from the expression phase. In Expt2, EB-, and not OIL-, treated rats showed sensitization to 0.5mg/kg amphetamine; neither group showed sensitization to 1.5mg/kg amphetamine (ceiling effect?). In Expt3, rats were treated with EB either in both the induction and expression phases, in one of the phases only, or in neither phase. There was an effect of hormone treatment on challenge day and not on induction day; rats given EB on Challenge day showed sensitization to 0.5mg/kg amphetamine; OIL rats did

Effect of clozapine on locomotor activity and anxiety-related behavior in the neonatal mice administered MK-801.

Science.gov (United States)

Pınar, Neslihan; Akillioglu, Kubra; Sefil, Fatih; Alp, Harun; Sagir, Mustafa; Acet, Ahmet

2015-08-11

Atypical antipsychotics have been used to treat fear and anxiety disturbance that are highly common in schizophrenic patients. It is suggested that disruptions of N-methyl-d-aspartate (NMDA)-mediated transmission of glutamate may underlie the pathophysiology of schizophrenia. The present study was conducted to analyze the effectiveness of clozapine on the anxiety-related behavior and locomotor function of the adult brain, which had previously undergone NMDA receptor blockade during a developmental period. In order to block the NMDA receptor, male mice were administered 0.25 mg/kg of MK-801 on days 7 to 10 postnatal. In adulthood, they were administered intraperitoneally 0.5 mg/kg of clozapine and tested with open-field and elevated plus maze test, to assess their emotional behavior and locomotor activity. In the group receiving MK-801 in the early developmental period the elevated plus maze test revealed a reduction in the anxiety-related behavior (ptest indicated a decrease in locomotor activity (plocomotor activity and anxiety-related behavior, induced by administration of the MK-801 in neonatal period.

Quantitative inferences on the locomotor behaviour of extinct species applied to Simocyon batalleri (Ailuridae, Late Miocene, Spain)

Science.gov (United States)

Fabre, Anne-Claire; Salesa, Manuel J.; Cornette, Raphael; Antón, Mauricio; Morales, Jorge; Peigné, Stéphane

2015-06-01

Inferences of function and ecology in extinct taxa have long been a subject of interest because it is fundamental to understand the evolutionary history of species. In this study, we use a quantitative approach to investigate the locomotor behaviour of Simocyon batalleri, a key taxon related to the ailurid family. To do so, we use 3D surface geometric morphometric approaches on the three long bones of the forelimb of an extant reference sample. Next, we test the locomotor strategy of S. batalleri using a leave-one-out cross-validated linear discriminant analysis. Our results show that S. batalleri is included in the morphospace of the living species of musteloids. However, each bone of the forelimb appears to show a different functional signal suggesting that inferring the lifestyle or locomotor behaviour of fossils can be difficult and dependent on the bone investigated. This highlights the importance of studying, where possible, a maximum of skeletal elements to be able to make robust inferences on the lifestyle of extinct species. Finally, our results suggest that S. batalleri may be more arboreal than previously suggested.

Anxiolytic-Like Effects and Increase in Locomotor Activity Induced by Infusions of NMDA into the Ventral Hippocampus in Rat: Interaction with GABAergic System.

Science.gov (United States)

Bina, Payvand; Rezvanfard, Mehrnaz; Ahmadi, Shamseddin; Zarrindast, Mohammad Reza

2014-10-01

In this study, we investigated the role of N-Methyl-D-Aspartate (NMDA) receptors in the ventral hippocampus (VH) and their possible interactions with GABAA system on anxiety-like behaviors. We used an elevated-plus maze test (EPM) to assess anxiety-like behaviors and locomotor activity in male Wistar rats. The results showed that intra-VH infusions of different doses of NMDA (0.25 and 0.5 μg/rat) increased locomotor activity, and also induced anxiolytic-like behaviors, as revealed by a tendency to increase percentage of open arm time (%OAT), and a significant increase in percentage of open arm entries (%OAE). The results also showed that intra-VH infusions of muscimol (0.5 and 1 μg/rat) or bicuculline (0.5 and 1 μg/rat) did not significantly affect anxiety-like behaviors, but bicuculline at dose of 1 μg/rat increased locomotor activity. Intra-VH co-infusions of muscimol (0.5 μg/rat) along with low doses of NMDA (0.0625 and 0.125 μg/rat) showed a tendency to increase %OAT, %OAE and locomotor activity; however, no interaction was observed between the drugs. Interestingly, intra-VH co-infusions of bicuculline (0.5 μg/rat) along with effective doses of NMDA (0.25 and 0.5 μg/rat) decreased %OAT, %OAE and locomotor activity, and a significant interaction between two drugs was observed. It can be concluded that GABAergic system may mediate the anxiolytic-like effects and increase in locomotor activity induced by NMDA in the VH.

Optimizing learning of a locomotor task: amplifying errors as needed.

Science.gov (United States)

Marchal-Crespo, Laura; López-Olóriz, Jorge; Jaeger, Lukas; Riener, Robert

2014-01-01

Research on motor learning has emphasized that errors drive motor adaptation. Thereby, several researchers have proposed robotic training strategies that amplify movement errors rather than decrease them. In this study, the effect of different robotic training strategies that amplify errors on learning a complex locomotor task was investigated. The experiment was conducted with a one degree-of freedom robotic stepper (MARCOS). Subjects were requested to actively coordinate their legs in a desired gait-like pattern in order to track a Lissajous figure presented on a visual display. Learning with three different training strategies was evaluated: (i) No perturbation: the robot follows the subjects' movement without applying any perturbation, (ii) Error amplification: existing errors were amplified with repulsive forces proportional to errors, (iii) Noise disturbance: errors were evoked with a randomly-varying force disturbance. Results showed that training without perturbations was especially suitable for a subset of initially less-skilled subjects, while error amplification seemed to benefit more skilled subjects. Training with error amplification, however, limited transfer of learning. Random disturbing forces benefited learning and promoted transfer in all subjects, probably because it increased attention. These results suggest that learning a locomotor task can be optimized when errors are randomly evoked or amplified based on subjects' initial skill level.

Thoracic Hemisection in Rats Results in Initial Recovery Followed by a Late Decrement in Locomotor Movements, with Changes in Coordination Correlated with Serotonergic Innervation of the Ventral Horn

Science.gov (United States)

Leszczyńska, Anna N.; Majczyński, Henryk; Wilczyński, Grzegorz M.; Sławińska, Urszula; Cabaj, Anna M.

2015-01-01

Lateral thoracic hemisection of the rodent spinal cord is a popular model of spinal cord injury, in which the effects of various treatments, designed to encourage locomotor recovery, are tested. Nevertheless, there are still inconsistencies in the literature concerning the details of spontaneous locomotor recovery after such lesions, and there is a lack of data concerning the quality of locomotion over a long time span after the lesion. In this study, we aimed to address some of these issues. In our experiments, locomotor recovery was assessed using EMG and CatWalk recordings and analysis. Our results showed that after hemisection there was paralysis in both hindlimbs, followed by a substantial recovery of locomotor movements, but even at the peak of recovery, which occurred about 4 weeks after the lesion, some deficits of locomotion remained present. The parameters that were abnormal included abduction, interlimb coordination and speed of locomotion. Locomotor performance was stable for several weeks, but about 3–4 months after hemisection secondary locomotor impairment was observed with changes in parameters, such as speed of locomotion, interlimb coordination, base of hindlimb support, hindlimb abduction and relative foot print distance. Histological analysis of serotonergic innervation at the lumbar ventral horn below hemisection revealed a limited restoration of serotonergic fibers on the ipsilateral side of the spinal cord, while on the contralateral side of the spinal cord it returned to normal. In addition, the length of these fibers on both sides of the spinal cord correlated with inter- and intralimb coordination. In contrast to data reported in the literature, our results show there is not full locomotor recovery after spinal cord hemisection. Secondary deterioration of certain locomotor functions occurs with time in hemisected rats, and locomotor recovery appears partly associated with reinnervation of spinal circuitry by serotonergic fibers. PMID

Low-energy extracorporeal shock wave therapy promotes vascular endothelial growth factor expression and improves locomotor recovery after spinal cord injury.

Science.gov (United States)

Yamaya, Seiji; Ozawa, Hiroshi; Kanno, Haruo; Kishimoto, Koshi N; Sekiguchi, Akira; Tateda, Satoshi; Yahata, Kenichiro; Ito, Kenta; Shimokawa, Hiroaki; Itoi, Eiji

2014-12-01

Extracorporeal shock wave therapy (ESWT) is widely used for the clinical treatment of various human diseases. Recent studies have demonstrated that low-energy ESWT upregulates the expression of vascular endothelial growth factor (VEGF) and promotes angiogenesis and functional recovery in myocardial infarction and peripheral artery disease. Many previous reports suggested that VEGF produces a neuroprotective effect to reduce secondary neural tissue damage after spinal cord injury (SCI). The purpose of the present study was to investigate whether low-energy ESWT promotes VEGF expression and neuroprotection and improves locomotor recovery after SCI. Sixty adult female Sprague-Dawley rats were randomly divided into 4 groups: sham group (laminectomy only), sham-SW group (low-energy ESWT applied after laminectomy), SCI group (SCI only), and SCI-SW group (low-energy ESWT applied after SCI). Thoracic spinal cord contusion injury was inflicted using an impactor. Low-energy ESWT was applied to the injured spinal cord 3 times a week for 3 weeks. Locomotor function was evaluated using the Basso, Beattie, and Bresnahan (BBB) Scale (open field locomotor score) at different time points over 42 days after SCI. Hematoxylin and eosin staining was performed to assess neural tissue damage in the spinal cord. Neuronal loss was investigated by immunostaining for NeuN. The mRNA expressions of VEGF and its receptor, Flt-1, in the spinal cord were assessed using real-time polymerase chain reaction. Immunostaining for VEGF was performed to evaluate VEGF protein expression in the spinal cord. In both the sham and sham-SW groups, no animals showed locomotor impairment on BBB scoring. Histological analysis of H & E and NeuN stainings in the sham-SW group confirmed that no neural tissue damage was induced by the low-energy ESWT. Importantly, animals in the SCI-SW group demonstrated significantly better locomotor improvement than those in the SCI group at 7, 35, and 42 days after injury (p

Technological dynamics and social capability: US states and European nations

Czech Academy of Sciences Publication Activity Database

Fagerberg, J.; Feldman, M.; Srholec, Martin

2014-01-01

Roč. 14, č. 2 (2014), s. 313-337 ISSN 1468-2702 Institutional support: PRVOUK-P23 Keywords : innovation * technological capability * social capability Subject RIV: AH - Economics Impact factor: 2.494, year: 2014

Competencies, Capabilities and the Neoschumpeterian Tradition

DEFF Research Database (Denmark)

Augier, Mie-Sophia; Teece, David J.

2004-01-01

In this paper, Mie Augier and David Teece outline the history and development of the ideas underlying an emerging approach within strategic management research: the dynamic capabili-ties framework. The framework was first outlined by Teece and Pisano (1994), and in the pre-sent paper elaborated...... theory of the firm) and Nelson and Winter (an evolutionary theory of economic change). In the dynamic capability framework firms and markets co-evolve. Managers are now allowed to perform distinct strate-gic roles in shaping both firms and their markets, e.g. through asset- selection and orchestra...... into a topic for further discussion. For example, Augier and Teece identify not only the merits but also the limitations of transaction costs eco-nomics. In this way, the authors pave the way for a more dynamic framework while drawing upon organization theory and scholars like Cyert and March (a behavioral...

Analysis of Indonesian Spice Essential Oil Compounds That Inhibit Locomotor Activity in Mice

Directory of Open Access Journals (Sweden)

Anas Subarnas

2011-04-01

Full Text Available Some fragrance components of spices used for cooking are known to have an effect on human behavior. The aim of this investigation was to examine the effect of the essential oils of basil (Ocimum formacitratum L. leaves, lemongrass (Cymbopogon citrates L. herbs, ki lemo (Litsea cubeba L. bark, and laja gowah (Alpinia malaccencis Roxb. rhizomes on locomotor activity in mice and identify the active component(s that might be responsible for the activity. The effect of the essential oils was studied by a wheel cage method and the active compounds of the essential oils were identified by GC/MS analysis. The essential oils were administered by inhalation at doses of 0.1, 0.3, and 0.5 mL/cage. The results showed that the four essential oils had inhibitory effects on locomotor activity in mice. Inhalation of the essential oils of basil leaves, lemongrass herbs, ki lemo bark, and laja gowah rhizomes showed the highest inhibitory activity at doses of 0.5 (57.64%, 0.1 (55.72%, 0.5 (60.75%, and 0.1 mL/cage (47.09%, respectively. The major volatile compounds 1,8-cineole, α-terpineol, 4-terpineol, citronelol, citronelal, and methyl cinnamate were identified in blood plasma of mice after inhalation of the four oils. These compounds had a significant inhibitory effect on locomotion after inhalation. The volatile compounds of essential oils identified in the blood plasma may correlate with the locomotor-inhibiting properties of the oil when administered by inhalation.

Methodical aspects of radionuclide study of locomotor system in patients with systemic diseases of connective tissue with single photon emission computed tomography

International Nuclear Information System (INIS)

Potsibyina, V.V.; Oderyij, Je.A.

1998-01-01

The original technique was used to examine 427 patients aged 18-64 with systemic diseases of locomotor system connective tissue and 65 controls. In addition to clinical studies, radionuclide signs of locomotor system lesions was investigated with NUCLETRON APEX SP-6 CT unit using labeled with Tc-99m and osteotropic radiopharmaceuticals

Temperature and Population Density Effects on Locomotor Activity of Musca domestica (Diptera: Muscidae)

DEFF Research Database (Denmark)

Schou, T. M.; Faurby, S.; Kjærsgaard, A.

2013-01-01

The behavior of ectotherm organisms is affected by both abiotic and biotic factors. However, a limited number of studies have investigated the synergistic effects on behavioral traits. This study examined the effect of temperature and density on locomotor activity of Musca domestica (L.). Locomot...

Locomotor activity and discriminative stimulus effects of a novel series of synthetic cathinone analogs in mice and rats.

Science.gov (United States)

Gatch, Michael B; Dolan, Sean B; Forster, Michael J

2017-04-01

Recent years have seen an increase in the recreational use of novel, synthetic psychoactive substances. There are little or no data on the abuse liability of many of the newer compounds. The current study investigated the discriminative stimulus and locomotor effects of a series of synthetic analogs of cathinone: α-pyrrolidinopropiophenone (α-PPP), α-pyrrolidinohexiophenone (α-PHP), α-pyrrolidinopentiothiophenone (α-PVT), 3,4-methylenedioxybutiophenone (MDPBP), and ethylone. Locomotor activity was assessed in an open-field assay using Swiss-Webster mice. Discriminative stimulus effects were assessed in Sprague-Dawley rats trained to discriminate either cocaine or methamphetamine from vehicle. Each of the compounds produced an inverted-U dose-effect on locomotor activity. Maximal effects were similar among the test compounds, but potencies varied with relative potencies of MDPBP > α-PPP = α-PHP > ethylone > α-PVT. Each of the test compounds substituted fully for the discriminative stimulus effects of methamphetamine. α-PPP, α-PHP, and ethylone fully substituted for cocaine. α-PVT produced a maximum of 50% cocaine-appropriate responding, and MDPBP produced an inverted-U-shaped dose-effect curve with maximum effects of 67%. These data provide initial evidence that these structurally similar, emerging novel psychoactive substances demonstrate potential for abuse and may be utilized for their stimulant-like effects, given their ability to stimulate locomotor activity and their substitution for the discriminative stimulus effects of the classical psychostimulants cocaine and/or methamphetamine.

The Evolving Dynamics of Organizational Capabilities

DEFF Research Database (Denmark)

Augier, Mie-Sophia

2004-01-01

In this paper, Mie Augier provides a rich description of the intellectual traditions, the signifi-cant people and academic institutions that in some way or another made a difference to Davis Teece's own intellectual development. In this sense, it is a dynamic account of the emerging career...

Technological dynamics and social capability: US states and European nations

Czech Academy of Sciences Publication Activity Database

Fagerberg, J.; Feldman, M.; Srholec, Martin

2014-01-01

Roč. 14, č. 2 (2014), s. 313-337 ISSN 1468-2702 R&D Projects: GA ČR GAP402/10/2310 Institutional support: RVO:67985998 Keywords : innovation * technological capability * social capability Subject RIV: AH - Economics Impact factor: 2.494, year: 2014

Low doses of ivermectin cause sensory and locomotor disorders in dung beetles

Science.gov (United States)

Verdú, José R.; Cortez, Vieyle; Ortiz, Antonio J.; González-Rodríguez, Estela; Martinez-Pinna, Juan; Lumaret, Jean-Pierre; Lobo, Jorge M.; Numa, Catherine; Sánchez-Piñero, Francisco

2015-09-01

Ivermectin is a veterinary pharmaceutical generally used to control the ecto- and endoparasites of livestock, but its use has resulted in adverse effects on coprophilous insects, causing population decline and biodiversity loss. There is currently no information regarding the direct effects of ivermectin on dung beetle physiology and behaviour. Here, based on electroantennography and spontaneous muscle force tests, we show sub-lethal disorders caused by ivermectin in sensory and locomotor systems of Scarabaeus cicatricosus, a key dung beetle species in Mediterranean ecosystems. Our findings show that ivermectin decreases the olfactory and locomotor capacity of dung beetles, preventing them from performing basic biological activities. These effects are observed at concentrations lower than those usually measured in the dung of treated livestock. Taking into account that ivermectin acts on both glutamate-gated and GABA-gated chloride ion channels of nerve and muscle cells, we predict that ivermectin’s effects at the physiological level could influence many members of the dung pat community. The results indicate that the decline of dung beetle populations could be related to the harmful effects of chemical contamination in the dung.

A simple behavioral test for locomotor function after brain injury in mice.

Science.gov (United States)

Tabuse, Masanao; Yaguchi, Masae; Ohta, Shigeki; Kawase, Takeshi; Toda, Masahiro

2010-11-01

To establish a simple and reliable test for assessing locomotor function in mice with brain injury, we developed a new method, the rotarod slip test, in which the number of slips of the paralytic hind limb from a rotarod is counted. Brain injuries of different severity were created in adult C57BL/6 mice, by inflicting 1-point, 2-point and 4-point cryo-injuries. These mice were subjected to the rotarod slip test, the accelerating rotarod test and the elevated body swing test (EBST). Histological analyses were performed to assess the severity of the brain damage. Significant and consistent correlations between test scores and severity were observed for the rotarod slip test and the EBST. Only the rotarod slip test detected the mild hindlimb paresis in the acute and sub-acute phase after injury. Our results suggest that the rotarod slip test is the most sensitive and reliable method for assessing locomotor function after brain damage in mice. Copyright © 2010 Elsevier Ltd. All rights reserved.

MRT of the locomotor system. 4. rev. and enl. ed.; MRT des Bewegungsapparats

Energy Technology Data Exchange (ETDEWEB)

Vahlensieck, Martin [Praxisnetz Radiologie und Nuklearmedizin Bonn Bad Godesberg - RheinSieg, Bonn (Germany); Reiser, Maximilian (ed.) [Klinikum Grosshadern, Muenchen (Germany). Inst. fuer Klinische Radiologie

2015-02-01

The book on MRT of the locomotor system covers the following topics: relevant NMT imaging techniques, spinal cord, shoulder, elbows, wrist and fingers, hip region, knee, lower leg - ankle - foot, temporomandibular joint, skeletal muscles, bone marrow, bone and soft tissue tumors, osteoporosis, sacroiliac joint, jaw and periodontium.

Age and egg-sac loss determine maternal behaviour and locomotor activity of wolf spiders (Araneae, Lycosidae).

Science.gov (United States)

Ruhland, Fanny; Chiara, Violette; Trabalon, Marie

2016-11-01

Wolf spiders' (Lycosidae) maternal behaviour includes a specific phase called "egg brooding" which consists of guarding and carrying an egg-sac throughout the incubation period. The transport of an egg-sac can restrict mothers' exploratory and locomotor activity, in particular when foraging. The present study details the ontogeny of maternal behaviour and assesses the influence of age of egg-sac (or embryos' developmental stage) on vagrant wolf spider Pardosa saltans females' exploration and locomotion. We observed these spiders' maternal behaviour in the laboratory and evaluated their locomotor activity using a digital activity recording device. Our subjects were virgin females (without egg-sac) and first time mothers (with her egg-sac) who were divided into three groups. The first group of mothers were tested on the day the egg-sac was built (day 0), and the females of the other two groups were tested 10 or 15days after they had built their egg-sac. We evaluated the effects of the presence and the loss of egg-sac on mothers' activity. Pardosa saltans females' behaviour depended on mothers' physiological state and/or age of egg-sac (developmental stage of embryos). Virgin females' behaviour was not modified by the presence of an egg-sac in their environment. Mothers' reactions to the presence, the loss and the recovery of their egg-sac varied during the maternal cycle. Maternal behaviour changed with age of egg-sac, but the levels of locomotor activity of mothers with egg-sacs was similar to those of virgin females. Loss of egg-sac modified the maternal behaviour and locomotor activity of all mothers; these modifications were greater on "day 15" when embryos had emerged from eggs. All mothers were able to retrieve their egg-sacs and to re-attach them to their spinnerets. Copyright © 2016 Elsevier B.V. All rights reserved.

Novelty response and 50 kHz ultrasonic vocalizations: Differential prediction of locomotor and affective response to amphetamine in Sprague-Dawley rats.

Science.gov (United States)

Garcia, Erik J; Cain, Mary E

2016-02-01

Novelty and sensation seeking (NSS) predisposes humans and rats to experiment with psychostimulants. In animal models, different tests of NSS predict different phases of drug dependence. Ultrasonic vocalizations (USVs) are evoked by psychomotor stimulants and measure the affective/motivation response to stimuli, yet the role NSS has on USVs in response to amphetamine is not determined. The aim of the present study was to determine if individual differences in NSS and USVs can predict locomotor and USV response to amphetamine (0.0, 0.3, and 1.0 mg/kg) after acute and chronic exposure. Thirty male rats were tested for their response to novelty (IEN), choice to engage in novelty (NPP), and heterospecific play (H-USV). Rats were administered non-contingent amphetamine or saline for seven exposures, and USVs and locomotor activity were measured. After a 14-day rest, rats were administered a challenge dose of amphetamine. Regression analyses indicated that amphetamine dose-dependently increased locomotor activity and the NPP test negatively predicted treatment-induced locomotor activity. The H-USV test predicted treatment-induced frequency-modulated (FM) USVs, but the strength of prediction depended on IEN response. Results provide evidence that locomotor activity and FM USVs induced by amphetamine represent different behavioral responses. The prediction of amphetamine-induced FM USVs by the H-USV screen was changed by the novelty response, indicating that the affective value of amphetamine-measured by FM USVs-depends on novelty response. This provides evidence that higher novelty responders may develop a tolerance faster and may escalate intake faster.

Limitations imposed by wearing armour on Medieval soldiers' locomotor performance

OpenAIRE

Askew, Graham N.; Formenti, Federico; Minetti, Alberto E.

2011-01-01

In Medieval Europe, soldiers wore steel plate armour for protection during warfare. Armour design reflected a trade-off between protection and mobility it offered the wearer. By the fifteenth century, a typical suit of field armour weighed between 30 and 50 kg and was distributed over the entire body. How much wearing armour affected Medieval soldiers' locomotor energetics and biomechanics is unknown. We investigated the mechanics and the energetic cost of locomotion in armour, and determined...

The number of postsynaptic currents necessary to produce locomotor- related cyclic information in neurons in the neonatal rat spinal cord

DEFF Research Database (Denmark)

Raastad, Morten; Johnson, Bruce R.; Kiehn, Ole

1996-01-01

To understand better how synaptic signaling contributes to network activity, we analyzed the potential contribution of putative unitary postsynaptic currents (PSCs) to locomotor-related information received by spinal interneurons in neonatal rats. The average cyclic modulation of the whole-cell c......-5) of the synapses contributing to the cyclic information need to be active simultaneously. This suggests that individual presynaptic cells in a central locomotor network can have a powerful influence on other neurons....

Analysis of stationary fuel cell dynamic ramping capabilities and ultra capacitor energy storage using high resolution demand data

Science.gov (United States)

Meacham, James R.; Jabbari, Faryar; Brouwer, Jacob; Mauzey, Josh L.; Samuelsen, G. Scott

Current high temperature fuel cell (HTFC) systems used for stationary power applications (in the 200-300 kW size range) have very limited dynamic load following capability or are simply base load devices. Considering the economics of existing electric utility rate structures, there is little incentive to increase HTFC ramping capability beyond 1 kWs -1 (0.4% s -1). However, in order to ease concerns about grid instabilities from utility companies and increase market adoption, HTFC systems will have to increase their ramping abilities, and will likely have to incorporate electrical energy storage (EES). Because batteries have low power densities and limited lifetimes in highly cyclic applications, ultra capacitors may be the EES medium of choice. The current analyses show that, because ultra capacitors have a very low energy storage density, their integration with HTFC systems may not be feasible unless the fuel cell has a ramp rate approaching 10 kWs -1 (4% s -1) when using a worst-case design analysis. This requirement for fast dynamic load response characteristics can be reduced to 1 kWs -1 by utilizing high resolution demand data to properly size ultra capacitor systems and through demand management techniques that reduce load volatility.

A Locomotor Deficit Induced by Sublethal Doses of Pyrethroid and Neonicotinoid Insecticides in the Honeybee Apis mellifera.

Science.gov (United States)

Charreton, Mercédès; Decourtye, Axel; Henry, Mickaël; Rodet, Guy; Sandoz, Jean-Christophe; Charnet, Pierre; Collet, Claude

2015-01-01

The toxicity of pesticides used in agriculture towards non-targeted organisms and especially pollinators has recently drawn the attention from a broad scientific community. Increased honeybee mortality observed worldwide certainly contributes to this interest. The potential role of several neurotoxic insecticides in triggering or potentiating honeybee mortality was considered, in particular phenylpyrazoles and neonicotinoids, given that they are widely used and highly toxic for insects. Along with their ability to kill insects at lethal doses, they can compromise survival at sublethal doses by producing subtle deleterious effects. In this study, we compared the bee's locomotor ability, which is crucial for many tasks within the hive (e.g. cleaning brood cells, feeding larvae…), before and after an acute sublethal exposure to one insecticide belonging to the two insecticide classes, fipronil and thiamethoxam. Additionally, we examined the locomotor ability after exposure to pyrethroids, an older chemical insecticide class still widely used and known to be highly toxic to bees as well. Our study focused on young bees (day 1 after emergence) since (i) few studies are available on locomotion at this stage and (ii) in recent years, pesticides have been reported to accumulate in different hive matrices, where young bees undergo their early development. At sublethal doses (SLD48h, i.e. causing no mortality at 48 h), three pyrethroids, namely cypermethrin (2.5 ng/bee), tetramethrin (70 ng/bee), tau-fluvalinate (33 ng/bee) and the neonicotinoid thiamethoxam (3.8 ng/bee) caused a locomotor deficit in honeybees. While the SLD48h of fipronil (a phenylpyrazole, 0.5 ng/bee) had no measurable effect on locomotion, we observed high mortality several days after exposure, an effect that was not observed with the other insecticides. Although locomotor deficits observed in the sublethal range of pyrethroids and thiamethoxam would suggest deleterious effects in the field, the case of

A Locomotor Deficit Induced by Sublethal Doses of Pyrethroid and Neonicotinoid Insecticides in the Honeybee Apis mellifera.

Directory of Open Access Journals (Sweden)

Mercédès Charreton

Full Text Available The toxicity of pesticides used in agriculture towards non-targeted organisms and especially pollinators has recently drawn the attention from a broad scientific community. Increased honeybee mortality observed worldwide certainly contributes to this interest. The potential role of several neurotoxic insecticides in triggering or potentiating honeybee mortality was considered, in particular phenylpyrazoles and neonicotinoids, given that they are widely used and highly toxic for insects. Along with their ability to kill insects at lethal doses, they can compromise survival at sublethal doses by producing subtle deleterious effects. In this study, we compared the bee's locomotor ability, which is crucial for many tasks within the hive (e.g. cleaning brood cells, feeding larvae…, before and after an acute sublethal exposure to one insecticide belonging to the two insecticide classes, fipronil and thiamethoxam. Additionally, we examined the locomotor ability after exposure to pyrethroids, an older chemical insecticide class still widely used and known to be highly toxic to bees as well. Our study focused on young bees (day 1 after emergence since (i few studies are available on locomotion at this stage and (ii in recent years, pesticides have been reported to accumulate in different hive matrices, where young bees undergo their early development. At sublethal doses (SLD48h, i.e. causing no mortality at 48 h, three pyrethroids, namely cypermethrin (2.5 ng/bee, tetramethrin (70 ng/bee, tau-fluvalinate (33 ng/bee and the neonicotinoid thiamethoxam (3.8 ng/bee caused a locomotor deficit in honeybees. While the SLD48h of fipronil (a phenylpyrazole, 0.5 ng/bee had no measurable effect on locomotion, we observed high mortality several days after exposure, an effect that was not observed with the other insecticides. Although locomotor deficits observed in the sublethal range of pyrethroids and thiamethoxam would suggest deleterious effects in the field

Locomotor Anatomy and Behavior of Patas Monkeys (Erythrocebus patas with Comparison to Vervet Monkeys (Cercopithecus aethiops

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Adrienne L. Zihlman

2013-01-01

Full Text Available Patas monkeys (Erythrocebus patas living in African savanna woodlands and grassland habitats have a locomotor system that allows them to run fast, presumably to avoid predators. Long fore- and hindlimbs, long foot bones, short toes, and a digitigrade foot posture were proposed as anatomical correlates with speed. In addition to skeletal proportions, soft tissue and whole body proportions are important components of the locomotor system. To further distinguish patas anatomy from other Old World monkeys, a comparative study based on dissection of skin, muscle, and bone from complete individuals of patas and vervet monkeys (Cercopithecus aethiops was undertaken. Analysis reveals that small adjustments in patas skeletal proportions, relative mass of limbs and tail, and specific muscle groups promote efficient sagittal limb motion. The ability to run fast is based on a locomotor system adapted for long distance walking. The patas’ larger home range and longer daily range than those of vervets give them access to highly dispersed, nutritious foods, water, and sleeping trees. Furthermore, patas monkeys have physiological adaptations that enable them to tolerate and dissipate heat. These features all contribute to the distinct adaptation that is the patas monkeys’ basis for survival in grassland and savanna woodland areas.

Locomotor activity and tissue levels following acute administration of lambda- and gamma-cyhalothrin in rats

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Moser, Virginia C., E-mail: Moser.ginger@epa.gov [Toxicity Assessment Division, National Health Effects and Environmental Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC (United States); Liu, Zhiwei [FMC Corporation, 701 Princeton South Corporate Center, Ewing, NJ (United States); Schlosser, Christopher [Health Effects Division, Office of Pesticide Programs, Office of Chemical Safety and Pollution Prevention, US Environmental Protection Agency, Washington, DC (United States); Spanogle, Terri L.; Chandrasekaran, Appavu [FMC Corporation, 701 Princeton South Corporate Center, Ewing, NJ (United States); McDaniel, Katherine L. [Toxicity Assessment Division, National Health Effects and Environmental Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC (United States)

2016-12-15

Pyrethroids produce neurotoxicity that depends, in part, on the chemical structure. Common behavioral effects include locomotor activity changes and specific toxic syndromes (types I and II). In general these neurobehavioral effects correlate well with peak internal dose metrics. Products of cyhalothrin, a type II pyrethroid, include mixtures of isomers (e.g., λ-cyhalothrin) as well as enriched active isomers (e.g., γ-cyhalothrin). We measured acute changes in locomotor activity in adult male rats and directly correlated these changes to peak brain and plasma concentrations of λ- and γ-cyhalothrin using a within-subject design. One-hour locomotor activity studies were conducted 1.5 h after oral gavage dosing, and immediately thereafter plasma and brains were collected for analyzing tissue levels using LC/MS/MS methods. Both isomers produced dose-related decreases in activity counts, and the effective dose range for γ-cyhalothrin was lower than for λ-cyhalothrin. Doses calculated to decrease activity by 50% were 2-fold lower for the γ-isomer (1.29 mg/kg) compared to λ-cyhalothrin (2.65 mg/kg). Salivation, typical of type II pyrethroids, was also observed at lower doses of γ-cyhalothrin. Administered dose correlated well with brain and plasma concentrations, which furthermore showed good correlations with activity changes. Brain and plasma levels were tightly correlated across doses. While γ-cyhalothrin was 2-fold more potent based on administered dose, the differences based on internal concentrations were less, with γ-cyhalothrin being 1.3- to 1.6-fold more potent than λ-cyhalothrin. These potency differences are consistent with the purity of the λ-isomer (approximately 43%) compared to the enriched isomer γ-cyhalothrin (approximately 98%). Thus, administered dose as well as differences in cyhalothrin isomers is a good predictor of behavioral effects. - Highlights: • Acute changes in locomotor activity were produced by λ- and γ-cyhalothrin. • �

Conditioned place preference and locomotor activity in response to methylphenidate, amphetamine and cocaine in mice lacking dopamine D4 receptors

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Thanos, P.K.; Thanos, P.K.; Bermeo, C.; Rubinstein, M.; Suchland, K.L.; Wang, G.-J.; Grandy, D.K.; Volkow, N.D.

2010-05-01

Methylphenidate (MP) and amphetamine (AMPH) are the most frequently prescribed medications for the treatment of attention-deficit/hyperactivity disorder (ADHD). Both drugs are believed to derive their therapeutic benefit by virtue of their dopamine (DA)-enhancing effects, yet an explanation for the observation that some patients with ADHD respond well to one medication but not to the other remains elusive. The dopaminergic effects of MP and AMPH are also thought to underlie their reinforcing properties and ultimately their abuse. Polymorphisms in the human gene that codes for the DA D4 receptor (D4R) have been repeatedly associated with ADHD and may correlate with the therapeutic as well as the reinforcing effects of responses to these psychostimulant medications. Conditioned place preference (CPP) for MP, AMPH and cocaine were evaluated in wild-type (WT) mice and their genetically engineered littermates, congenic on the C57Bl/6J background, that completely lack D4Rs (knockout or KO). In addition, the locomotor activity in these mice during the conditioning phase of CPP was tested in the CPP chambers. D4 receptor KO and WT mice showed CPP and increased locomotor activity in response to each of the three psychostimulants tested. D4R differentially modulates the CPP responses to MP, AMPH and cocaine. While the D4R genotype affected CPP responses to MP (high dose only) and AMPH (low dose only) it had no effects on cocaine. Inasmuch as CPP is considered an indicator of sensitivity to reinforcing responses to drugs these data suggest a significant but limited role of D4Rs in modulating conditioning responses to MP and AMPH. In the locomotor test, D4 receptor KO mice displayed attenuated increases in AMPH-induced locomotor activity whereas responses to cocaine and MP did not differ. These results suggest distinct mechanisms for D4 receptor modulation of the reinforcing (perhaps via attenuating dopaminergic signalling) and locomotor properties of these stimulant drugs

Leveraging marketing capabilities into competitive advantage and export performance.

OpenAIRE

Tan, Q.; Sousa, C. M. P.

2015-01-01

Purpose – By using the dynamic capabilities (DC) theory and the theory of competitive advantage, the purpose of this paper is to develop a framework to investigate the role of marketing capabilities on the firm’s export performance. Specifically, this framework depicts the consequences of marketing capabilities and focuses on the relationships among marketing capabilities, competitive advantage, and export performance. Design/methodology/approach – The authors conduct a meta-analysis of ...

Locomotor sensory organization test: a novel paradigm for the assessment of sensory contributions in gait.

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Chien, Jung Hung; Eikema, Diderik-Jan Anthony; Mukherjee, Mukul; Stergiou, Nicholas

2014-12-01

Feedback based balance control requires the integration of visual, proprioceptive and vestibular input to detect the body's movement within the environment. When the accuracy of sensory signals is compromised, the system reorganizes the relative contributions through a process of sensory recalibration, for upright postural stability to be maintained. Whereas this process has been studied extensively in standing using the Sensory Organization Test (SOT), less is known about these processes in more dynamic tasks such as locomotion. In the present study, ten healthy young adults performed the six conditions of the traditional SOT to quantify standing postural control when exposed to sensory conflict. The same subjects performed these six conditions using a novel experimental paradigm, the Locomotor SOT (LSOT), to study dynamic postural control during walking under similar types of sensory conflict. To quantify postural control during walking, the net Center of Pressure sway variability was used. This corresponds to the Performance Index of the center of pressure trajectory, which is used to quantify postural control during standing. Our results indicate that dynamic balance control during locomotion in healthy individuals is affected by the systematic manipulation of multisensory inputs. The sway variability patterns observed during locomotion reflect similar balance performance with standing posture, indicating that similar feedback processes may be involved. However, the contribution of visual input is significantly increased during locomotion, compared to standing in similar sensory conflict conditions. The increased visual gain in the LSOT conditions reflects the importance of visual input for the control of locomotion. Since balance perturbations tend to occur in dynamic tasks and in response to environmental constraints not present during the SOT, the LSOT may provide additional information for clinical evaluation on healthy and deficient sensory processing.

Functional organization of V2a-related locomotor circuits in the rodent spinal cord

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Dougherty, Kimberly J.; Kiehn, Ole

2010-01-01

Studies of mammalian locomotion have been greatly facilitated by the use of the isolated rodent spinal cord preparation that retains the locomotor circuits needed to execute the movement. Physiological and molecular genetic experiments in this preparation have started to unravel the basic circuit...

Modulation of spontaneous locomotor and respiratory drives to hindlimb motoneurons temporally related to sympathetic drives as revealed by Mayer waves.

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Wienecke, Jacob; Enríquez Denton, Manuel; Stecina, Katinka; Kirkwood, Peter A; Hultborn, Hans

2015-01-01

In this study we investigated how the networks mediating respiratory and locomotor drives to lumbar motoneurons interact and how this interaction is modulated in relation to periodic variations in blood pressure (Mayer waves). Seven decerebrate cats, under neuromuscular blockade, were used to study central respiratory drive potentials (CRDPs, usually enhanced by added CO2) and spontaneously occurring locomotor drive potentials (LDPs) in hindlimb motoneurons, together with hindlimb and phrenic nerve discharges. In four of the cats both drives and their voltage-dependent amplification were absent or modest, but in the other three, one or other of these drives was common and the voltage-dependent amplification was frequently strong. Moreover, in these three cats the blood pressure showed marked periodic variation (Mayer waves), with a slow rate (periods 9-104 s, mean 39 ± 17 SD). Profound modulation, synchronized with the Mayer waves was seen in the occurrence and/or in the amplification of the CRDPs or LDPs. In one animal, where CRDPs were present in most cells and the amplification was strong, the CRDP consistently triggered sustained plateaux at one phase of the Mayer wave cycle. In the other two animals, LDPs were common, and the occurrence of the locomotor drive was gated by the Mayer wave cycle, sometimes in alternation with the respiratory drive. Other interactions between the two drives involved respiration providing leading events, including co-activation of flexors and extensors during post-inspiration or a locomotor drive gated or sometimes entrained by respiration. We conclude that the respiratory drive in hindlimb motoneurons is transmitted via elements of the locomotor central pattern generator. The rapid modulation related to Mayer waves suggests the existence of a more direct and specific descending modulatory control than has previously been demonstrated.

Modulation of spontaneous locomotor and respiratory drives to hindlimb motoneurons temporally related to sympathetic drives as revealed by Mayer waves

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Katinka eStecina

2015-02-01

Full Text Available In this study we investigated how the networks mediating respiratory and locomotor drives to lumbar motoneurons interact and how this interaction is modulated in relation to periodic variations in blood pressure (Mayer waves. Seven decerebrate cats, under neuromuscular blockade, were used to study central respiratory drive potentials (CRDPs, usually enhanced by added CO2 and spontaneously occurring locomotor drive potentials (LDPs in hindlimb motoneurons, together with hindlimb and phrenic nerve discharges. In four of the cats both drives and their voltage-dependent amplification were absent or modest, but in the other three, one or other of these drives was common and the voltage-dependent amplification was frequently strong. Moreover, in these three cats the blood pressure showed marked periodic variation (Mayer waves, with a slow rate (periods 9 - 104 s, mean 39 ± 17 SD. Profound modulation, synchronized with the Mayer waves was seen in the occurrence and/or in the amplification of the CRDPs or LDPs. In one animal, where CRDPs were present in most cells and the amplification was strong, the CRDP consistently triggered sustained plateaux at one phase of the Mayer wave cycle. In the other two animals, LDPs were common, and the occurrence of the locomotor drive was gated by the Mayer wave cycle, sometimes in alternation with the respiratory drive. Other interactions between the two drives involved respiration providing leading events, including co-activation of flexors and extensors during post-inspiration or a locomotor drive gated or sometimes entrained by respiration. We conclude that the respiratory drive in hindlimb motoneurons is transmitted via elements of the locomotor central pattern generator. The rapid modulation related to Mayer waves suggests the existence of a more direct and specific descending modulatory control than has previously been demonstrated.

Sex differences in locomotor effects of morphine in the rat

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Craft, Rebecca M.; Clark, James L.; Hart, Stephen P.; Pinckney, Megan K.

2006-01-01

Sex differences in reinforcing, analgesic and other effects of opioids have been demonstrated; however, the extent to which sex differences in motoric effects of opioids contribute to apparent sex differences in their primary effects is not known. The goal of this study was to compare the effects of the prototypic mu opioid agonist morphine on locomotor activity in male vs. female rats. Saline or morphine (1-10 mg/kg) was administered s.c. to adult Sprague-Dawley rats, which were placed into ...

Capabilities and Equality of Health II

DEFF Research Database (Denmark)

Keiding, Hans

The concept of capabilities, introduced originally by Sen, has inspired many researchers but has not found any simple formal representation which might be instrumental in the construction of a comprehensive theory of equality. In a previous paper (Keiding, 2005), we investigated whether preferences...... of the capability approach to questions of health or equality. In the present paper we extend the notion of rationalizing orderings of capabilities to a dynamical context, in the sense that the utility function is not yet revealed to the individual at the time when the capabilities are ordered. It turns out...... over capabilities as sets of functionings can be rationalized by maximization of a suitable utility function over the set of functionings. Such a rationalization turned out to be possible only in cases which must be considered exceptional and which do not allowfor interesting applications...

InfoSymbiotics/DDDAS - The power of Dynamic Data Driven Applications Systems for New Capabilities in Environmental -, Geo-, and Space- Sciences

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Darema, F.

2016-12-01

InfoSymbiotics/DDDAS embodies the power of Dynamic Data Driven Applications Systems (DDDAS), a concept whereby an executing application model is dynamically integrated, in a feed-back loop, with the real-time data-acquisition and control components, as well as other data sources of the application system. Advanced capabilities can be created through such new computational approaches in modeling and simulations, and in instrumentation methods, and include: enhancing the accuracy of the application model; speeding-up the computation to allow faster and more comprehensive models of a system, and create decision support systems with the accuracy of full-scale simulations; in addition, the notion of controlling instrumentation processes by the executing application results in more efficient management of application-data and addresses challenges of how to architect and dynamically manage large sets of heterogeneous sensors and controllers, an advance over the static and ad-hoc ways of today - with DDDAS these sets of resources can be managed adaptively and in optimized ways. Large-Scale-Dynamic-Data encompasses the next wave of Big Data, and namely dynamic data arising from ubiquitous sensing and control in engineered, natural, and societal systems, through multitudes of heterogeneous sensors and controllers instrumenting these systems, and where opportunities and challenges at these "large-scales" relate not only to data size but the heterogeneity in data, data collection modalities, fidelities, and timescales, ranging from real-time data to archival data. In tandem with this important dimension of dynamic data, there is an extended view of Big Computing, which includes the collective computing by networked assemblies of multitudes of sensors and controllers, this range from the high-end to the real-time seamlessly integrated and unified, and comprising the Large-Scale-Big-Computing. InfoSymbiotics/DDDAS engenders transformative impact in many application domains

Complexity, fractal dynamics and determinism in treadmill ambulation: Implications for clinical biomechanists.

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Hollman, John H; Watkins, Molly K; Imhoff, Angela C; Braun, Carly E; Akervik, Kristen A; Ness, Debra K

2016-08-01

Reduced inter-stride complexity during ambulation may represent a pathologic state. Evidence is emerging that treadmill training for rehabilitative purposes may constrain the locomotor system and alter gait dynamics in a way that mimics pathological states. The purpose of this study was to examine the dynamical system components of gait complexity, fractal dynamics and determinism during treadmill ambulation. Twenty healthy participants aged 23.8 (1.2) years walked at preferred walking speeds for 6min on a motorized treadmill and overground while wearing APDM 6 Opal inertial monitors. Stride times, stride lengths and peak sagittal plane trunk velocities were measured. Mean values and estimates of complexity, fractal dynamics and determinism were calculated for each parameter. Data were compared between overground and treadmill walking conditions. Mean values for each gait parameter were statistically equivalent between overground and treadmill ambulation (P>0.05). Through nonlinear analyses, however, we found that complexity in stride time signals (P<0.001), and long-range correlations in stride time and stride length signals (P=0.005 and P=0.024, respectively), were reduced on the treadmill. Treadmill ambulation induces more predictable inter-stride time dynamics and constrains fluctuations in stride times and stride lengths, which may alter feedback from destabilizing perturbations normally experienced by the locomotor control system during overground ambulation. Treadmill ambulation, therefore, may provide less opportunity for experiencing the adaptability necessary to successfully ambulate overground. Investigators and clinicians should be aware that treadmill ambulation will alter dynamic gait characteristics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Immature spinal locomotor output in children with Cerebral Palsy

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Germana Cappellini

2016-10-01

Full Text Available Detailed descriptions of gait impairments have been reported in cerebral palsy (CP, but it is still unclear how maturation of the spinal motoneuron output is affected. Spatiotemporal alpha-motoneuron activation during walking can be assessed by mapping the electromyographic activity profiles from several, simultaneously recorded muscles onto the anatomical rostrocaudal location of the motoneuron pools in the spinal cord, and by means of factor analysis of the muscle activity profiles. Here, we analysed gait kinematics and EMG activity of 11 pairs of bilateral muscles with lumbosacral innervation in 35 children with CP (19 diplegic, 16 hemiplegic, 2-12 years and 33 typically developing (TD children (1-12 years. TD children showed a progressive reduction of EMG burst durations and a gradual reorganization of the spatiotemporal motoneuron output with increasing age. By contrast, children with CP showed very limited age-related changes of EMG durations and motoneuron output, as well as of limb intersegmental coordination and foot trajectory control (on both sides for diplegic children and the affected side for hemiplegic children. Factorization of the EMG signals revealed a comparable structure of the motor output in children with CP and TD children, but significantly wider temporal activation patterns in children with CP, resembling the patterns of much younger TD infants. A similar picture emerged when considering the spatiotemporal maps of alpha-motoneuron activation. Overall, the results are consistent with the idea that early injuries to developing motor regions of the brain substantially affect the maturation of the spinal locomotor output and consequently the future locomotor behaviour.

The locomotor activity of soccer players based on playing positions during the 2010 World Cup.

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Soroka, Andrzej

2018-06-01

The aim of this study was to define the locomotor activity of footballer players during the 2010 World Cup and to assess what differences existed among different playing positions. Research was conducted using research material collected from the Castrol Performance Index, a kinematic game analysis system that records player movements during a game by use of semi-automatic cameras. A total of 599 players who participated in the championships were analyzed. The results were evaluated using one-way analysis of variance (ANOVA) and a post-hoc test that calculated the Honestly Significant Difference (HSD) in order to determine which mean values significantly differed among the player positions. It was found that midfielders covered on average the largest distance during a match (10,777.6 m, Plocomotor activity at high and sprint intensities (2936.8 m and 108.4 m, respectively). Additionally, midfielders also spent the largest amount of time at performing at a high intensity (10.6%). Strikers also featured high levels of the above parameters; the total length of distance covered with high intensities was found to be on average 2586.7 m, the distance covered at sprint intensity was 105 m. The footballers, playing at the championship level feature excellent locomotor preparation. This fact is undoubtedly supported by the aerobic training of high intensity. Such training allows footballers to extend the distance they cover during the match, increase the intensity of locomotor activities and sprint speed distance.

Catalase inhibition in the Arcuate nucleus blocks ethanol effects on the locomotor activity of rats.

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Sanchis-Segura, Carles; Correa, Mercé; Miquel, Marta; Aragon, Carlos M G

2005-03-07

Previous studies have demonstrated that there is a bidirectional modulation of ethanol-induced locomotion produced by drugs that regulate brain catalase activity. In the present study we have assessed the effect in rats of intraperitoneal, intraventricular or intracraneal administration of the catalase inhibitor sodium azide in the locomotor changes observed after ethanol (1 g/kg) administration. Our results show that sodium azide prevents the effects of ethanol in rats locomotion not only when sodium azide was systemically administered but also when it was intraventricularly injected, then confirming that the interaction between catalase and ethanol takes place in Central Nervous System (CNS). Even more interestingly, the same results were observed when sodium azide administration was restricted to the hypothalamic Arcuate nucleus (ARC), a brain region which has one of the highest levels of expression of catalase. Therefore, the results of the present study not only confirm a role for brain catalase in the mediation of ethanol-induced locomotor changes in rodents but also point to the ARC as a major neuroanatomical location for this interaction. These results are in agreement with our reports showing that ethanol-induced locomotor changes are clearly dependent of the ARC integrity and, especially of the POMc-synthesising neurons of this nucleus. According to these data we propose a model in which ethanol oxidation via catalase could produce acetaldehyde into the ARC and to promote a release of beta-endorphins that would activate opioid receptors to produce locomotion and other ethanol-induced neurobehavioural changes.

Locomotor activity and tissue levels following acute administration of lambda- and gamma-cyhalothrin in rats

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Pyrethroids produce neurotoxicity that depends, in part, on the chemical structure. Common behavioral effects include locomotor activity changes and specific toxic syndromes (types I and II). In general these neurobehavioral effects correlate well with peak internal dose metric...

Dynamic Positioning Capability Analysis for Marine Vessels Based on A DPCap Polar Plot Program

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Wang, Lei; Yang, Jian-min; Xu, Sheng-wen

2018-03-01

Dynamic positioning capability (DPCap) analysis is essential in the selection of thrusters, in their configuration, and during preliminary investigation of the positioning ability of a newly designed vessel dynamic positioning system. DPCap analysis can help determine the maximum environmental forces, in which the DP system can counteract in given headings. The accuracy of the DPCap analysis is determined by the precise estimation of the environmental forces as well as the effectiveness of the thrust allocation logic. This paper is dedicated to developing an effective and efficient software program for the DPCap analysis for marine vessels. Estimation of the environmental forces can be obtained by model tests, hydrodynamic computation and empirical formulas. A quadratic programming method is adopted to allocate the total thrust on every thruster of the vessel. A detailed description of the thrust allocation logic of the software program is given. The effectiveness of the new program DPCap Polar Plot (DPCPP) was validated by a DPCap analysis for a supply vessel. The present study indicates that the developed program can be used in the DPCap analysis for marine vessels. Moreover, DPCap analysis considering the thruster failure mode might give guidance to the designers of vessels whose thrusters need to be safer.

"COUPLED PROCESSES" AS DYNAMIC CAPABILITIES IN SYSTEMS INTEGRATION

OpenAIRE

Chagas Jr, Milton de Freitas; Leite, Dinah Eluze Sales; Jesus, Gabriel Torres de

2017-01-01

ABSTRACT The dynamics of innovation in complex systems industries is becoming an independent research stream. Apart from conventional uncertainties related to commerce and technology, complex-system industries must cope with systemic uncertainty. This paper's objective is to analyze evolving technological paths from one product generation to the next through two case studies in the Brazilian aerospace industry, considering systems integration as an empirical instantiation of dynamic capabilit...

Individual differences in circadian locomotor parameters correlate with anxiety- and depression-like behavior.

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Jeffrey Anyan

Full Text Available Disrupted circadian rhythms are a core feature of mood and anxiety disorders. Circadian rhythms are coordinated by a light-entrainable master clock located in the suprachiasmatic nucleus. Animal models of mood and anxiety disorders often exhibit blunted rhythms in locomotor activity and clock gene expression. Interestingly, the changes in circadian rhythms correlate with mood-related behaviours. Although animal models of depression and anxiety exhibit aberrant circadian rhythms in physiology and behavior, it is possible that the methodology being used to induce the behavioral phenotype (e.g., brain lesions, chronic stress, global gene deletion affect behavior independently of circadian system. This study investigates the relationship between individual differences in circadian locomotor parameters and mood-related behaviors in healthy rats. The circadian phenotype of male Lewis rats was characterized by analyzing wheel running behavior under standard 12h:12h LD conditions, constant dark, constant light, and rate of re-entrainment to a phase advance. Rats were then tested on a battery of behavioral tests: activity box, restricted feeding, elevated plus maze, forced swim test, and fear conditioning. Under 12h:12h LD conditions, percent of daily activity in the light phase and variability in activity onset were associated with longer latency to immobility in the forced swim test. Variability in onset also correlated positively with anxiety-like behavior in the elevated plus maze. Rate of re-entrainment correlated positively with measures of anxiety in the activity box and elevated plus maze. Lastly, we found that free running period under constant dark was associated with anxiety-like behaviors in the activity box and elevated plus maze. Our results provide a previously uncharacterized relationship between circadian locomotor parameters and mood-related behaviors in healthy rats and provide a basis for future examination into circadian clock

Transgenic APP expression during postnatal development causes persistent locomotor hyperactivity in the adult.

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Rodgers, Shaefali P; Born, Heather A; Das, Pritam; Jankowsky, Joanna L

2012-06-18

Transgenic mice expressing disease-associated proteins have become standard tools for studying human neurological disorders. Transgenes are often expressed using promoters chosen to drive continuous high-level expression throughout life rather than temporal and spatial fidelity to the endogenous gene. This approach has allowed us to recapitulate diseases of aging within the two-year lifespan of the laboratory mouse, but has the potential for creating aberrant phenotypes by mechanisms unrelated to the human disorder. We show that overexpression of the Alzheimer's-related amyloid precursor protein (APP) during early postnatal development leads to severe locomotor hyperactivity that can be significantly attenuated by delaying transgene onset until adulthood. Our data suggest that exposure to transgenic APP during maturation influences the development of neuronal circuits controlling motor activity. Both when matched for total duration of APP overexpression and when matched for cortical amyloid burden, animals exposed to transgenic APP as juveniles are more active in locomotor assays than animals in which APP overexpression was delayed until adulthood. In contrast to motor activity, the age of APP onset had no effect on thigmotaxis in the open field as a rough measure of anxiety, suggesting that the interaction between APP overexpression and brain development is not unilateral. Our findings indicate that locomotor hyperactivity displayed by the tet-off APP transgenic mice and several other transgenic models of Alzheimer's disease may result from overexpression of mutant APP during postnatal brain development. Our results serve as a reminder of the potential for unexpected interactions between foreign transgenes and brain development to cause long-lasting effects on neuronal function in the adult. The tet-off APP model provides an easy means of avoiding developmental confounds by allowing transgene expression to be delayed until the mice reach adulthood.

Early application of tail nerve electrical stimulation-induced walking training promotes locomotor recovery in rats with spinal cord injury.

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Zhang, S-X; Huang, F; Gates, M; Shen, X; Holmberg, E G

2016-11-01

This is a randomized controlled prospective trial with two parallel groups. The objective of this study was to determine whether early application of tail nerve electrical stimulation (TANES)-induced walking training can improve the locomotor function. This study was conducted in SCS Research Center in Colorado, USA. A contusion injury to spinal cord T10 was produced using the New York University impactor device with a 25 -mm height setting in female, adult Long-Evans rats. Injured rats were randomly divided into two groups (n=12 per group). One group was subjected to TANES-induced walking training 2 weeks post injury, and the other group, as control, received no TANES-induced walking training. Restorations of behavior and conduction were assessed using the Basso, Beattie and Bresnahan open-field rating scale, horizontal ladder rung walking test and electrophysiological test (Hoffmann reflex). Early application of TANES-induced walking training significantly improved the recovery of locomotor function and benefited the restoration of Hoffmann reflex. TANES-induced walking training is a useful method to promote locomotor recovery in rats with spinal cord injury.

Using step width to compare locomotor biomechanics between extinct, non-avian theropod dinosaurs and modern obligate bipeds.

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Bishop, P J; Clemente, C J; Weems, R E; Graham, D F; Lamas, L P; Hutchinson, J R; Rubenson, J; Wilson, R S; Hocknull, S A; Barrett, R S; Lloyd, D G

2017-07-01

How extinct, non-avian theropod dinosaurs locomoted is a subject of considerable interest, as is the manner in which it evolved on the line leading to birds. Fossil footprints provide the most direct evidence for answering these questions. In this study, step width-the mediolateral (transverse) distance between successive footfalls-was investigated with respect to speed (stride length) in non-avian theropod trackways of Late Triassic age. Comparable kinematic data were also collected for humans and 11 species of ground-dwelling birds. Permutation tests of the slope on a plot of step width against stride length showed that step width decreased continuously with increasing speed in the extinct theropods ( p < 0.001), as well as the five tallest bird species studied ( p < 0.01). Humans, by contrast, showed an abrupt decrease in step width at the walk-run transition. In the modern bipeds, these patterns reflect the use of either a discontinuous locomotor repertoire, characterized by distinct gaits (humans), or a continuous locomotor repertoire, where walking smoothly transitions into running (birds). The non-avian theropods are consequently inferred to have had a continuous locomotor repertoire, possibly including grounded running. Thus, features that characterize avian terrestrial locomotion had begun to evolve early in theropod history. © 2017 The Author(s).

Effects of pregnancy on body temperature and locomotor performance of velvet geckos.

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Dayananda, Buddhi; Ibargüengoytía, Nora; Whiting, Martin J; Webb, Jonathan K

2017-04-01

Pregnancy is a challenging period for egg laying squamates. Carrying eggs can encumber females and decrease their locomotor performance, potentially increasing their risk of predation. Pregnant females can potentially reduce this handicap by selecting higher temperatures to increase their sprint speed and ability to escape from predators, or to speed up embryonic development and reduce the period during which they are burdened with eggs ('selfish mother' hypothesis). Alternatively, females might select more stable body temperatures during pregnancy to enhance offspring fitness ('maternal manipulation hypothesis'), even if the maintenance of such temperatures compromises a female's locomotor performance. We investigated whether pregnancy affects the preferred body temperatures and locomotor performance of female velvet geckos Amalosia lesueurii. We measured running speed of females during late pregnancy, and one week after they laid eggs at four temperatures (20°, 25°, 30° and 35°C). Preferred body temperatures of females were measured in a cost-free thermal gradient during late pregnancy and one week after egg-laying. Females selected higher and more stable set-point temperatures when they were pregnant (mean =29.0°C, T set =27.8-30.5°C) than when they were non-pregnant (mean =26.2°C, T set =23.7-28.7°C). Pregnancy was also associated with impaired performance; females sprinted more slowly at all four test temperatures when burdened with eggs. Although females selected higher body temperatures during late pregnancy, this increase in temperature did not compensate for their impaired running performance. Hence, our results suggest that females select higher temperatures during pregnancy to speed up embryogenesis and reduce the period during which they have reduced performance. This strategy may decrease a female's probability of encountering predatory snakes that use the same microhabitats for thermoregulation. Selection of stable temperatures by pregnant

Runners maintain locomotor-respiratory coupling following isocapnic voluntary hyperpnea to task failure.

Science.gov (United States)

Stickford, Abigail S L; Stickford, Jonathon L; Tanner, David A; Stager, Joel M; Chapman, Robert F

2015-11-01

Evidence has long suggested that mammalian ventilatory and locomotor rhythms are linked, yet determinants and implications of locomotor-respiratory coupling (LRC) continue to be investigated. Anecdotally, respiratory muscle fatigue seen at the end of heavy exercise may result in an uncoupling of movement-ventilation rhythms; however, there is no scientific evidence to substantiate this claim. We sought to determine whether or not fatigue of the respiratory muscles alters locomotor-respiratory coupling patterns typically observed in highly trained individuals while running. A related query was to examine the relationship between the potential changes in LRC and measures of running economy. Twelve male distance runners ran at four submaximal workloads (68-89 % VO2peak) on two separate days while LRC was quantified. One LRC trial served as a control (CON), while the other was performed following an isocapnic voluntary hyperpnea to task failure to induce respiratory muscle fatigue (FT+). LRC was assessed as stride-to-breathing frequency ratios (SF/fB) and degree of LRC (percentage of breaths occurring during the same decile of the step cycle). Hyperpnea resulted in significant declines in maximal voluntary inspiratory (MIP) and expiratory (MEP) mouth pressures (ΔMIP = -10 ± 12 cm H2O; ΔMEP = -6 ± 9 cm H2O). There were no differences in minute ventilation between CON and FT+ (CON, all speeds pooled = 104 ± 25 L min(-1); FT+ pooled = 106 ± 23 L min(-1)). Stride frequency was not different between trials; however, breathing frequency was significantly greater during FT+ compared to CON at all speeds (CON pooled = 47 ± 10 br min(-1); FT+ pooled = 52 ± 9 br min(-1)), resulting in smaller corresponding SF/fB. Yet, the degree of LRC was the same during CON and FT+ (CON pooled = 63 ± 15 %; FT+ pooled = 64 ± 18 %). The results indicate that trained runners are able to continue entraining breath and step cycles, despite marked changes in exercise breathing frequency

The Nicotine-Evoked Locomotor Response: A Behavioral Paradigm for Toxicity Screening in Zebrafish (Danio rerio Embryos and Eleutheroembryos Exposed to Methylmercury.

Directory of Open Access Journals (Sweden)

Francisco X Mora-Zamorano

Full Text Available This study is an adaptation of the nicotine-evoked locomotor response (NLR assay, which was originally utilized for phenotype-based neurotoxicity screening in zebrafish embryos. Zebrafish embryos do not exhibit spontaneous swimming until roughly 4 days post-fertilization (dpf, however, a robust swimming response can be induced as early as 36 hours post-fertilization (hpf by means of acute nicotine exposure (30-240μM. Here, the NLR was tested as a tool for early detection of locomotor phenotypes in 36, 48 and 72 hpf mutant zebrafish embryos of the non-touch-responsive maco strain; this assay successfully discriminated mutant embryos from their non-mutant siblings. Then, methylmercury (MeHg was used as a proof-of-concept neurotoxicant to test the effectiveness of the NLR assay as a screening tool in toxicology. The locomotor effects of MeHg were evaluated in 6 dpf wild type eleutheroembryos exposed to waterborne MeHg (0, 0.01, 0.03 and 0.1μM. Afterwards, the NLR assay was tested in 48 hpf embryos subjected to the same MeHg exposure regimes. Embryos exposed to 0.01 and 0.03μM of MeHg exhibited significant increases in locomotion in both scenarios. These findings suggest that similar locomotor phenotypes observed in free swimming fish can be detected as early as 48 hpf, when locomotion is induced with nicotine.

The Protective Effect of Quince (Cydonia oblonga Miller Leaf Extract on Locomotor Activity and Anxiety-Like Behaviors in a Ketamine Model of Schizophrenia

Directory of Open Access Journals (Sweden)

Akbar Hajizadeh Moghaddam

2016-08-01

Full Text Available Abstract Background: Schizophrenia is a chronic debilitating psychiatric disorder affecting 1% of the population worldwide. As for key role of free radicals in the development of this disease and that Quince leaf is a natural source of antioxidant substances, this study was aimed to evaluate the protective effects of Quince leaf extract on locomotor activity and anxiety-like behaviors by an intraperitoneal injection of ketamine in male mice in a ketamine model of schizophrenia. Materials and Methods: In the experimental research, male adult mice were divided into six groups including: control, Sham (received water orally and saline intraperitoneally, psychosis group (received 10 mg/kg/day ketamine i.p. for 10 days and treated psychosis groups (received 50, 100 and 150 mg/kg/day. Treated groups received hydroalcoholic Quince leaf extract orally for 3 weeks before injection of ketamine. Extract gavages continue for 5 days after the last ketamine injection. Locomotor activity and anxiety-like behavioral changes were measured in the open-field test. Results: The results showed that chronic administration of ketamine increases horizontal locomotor activity and anxiety like behaviors (p≤0.001 and pretreatment of Quince leaf extract effectively decreases horizontal locomotor activity (p<0.001 and increases duration that spends in middle area of Open field (p<0.01 and vertical ocomotor activity(p<0.001. Conclusion: The results of this research showed that chronic administration of Quince leaf extract improves locomotor disorder and induced anxiety-like behaviors by having antioxidant properties in a ketamine model of schizophrenia.

Locomotor Adaptation Improves Balance Control, Multitasking Ability and Reduces the Metabolic Cost of Postural Instability

Science.gov (United States)

Bloomberg, J. J.; Peters, B. T.; Mulavara, A. P.; Brady, R. A.; Batson, C. D.; Miller, C. A.; Ploutz-Snyder, R. J.; Guined, J. R.; Buxton, R. E.; Cohen, H. S.

2011-01-01

During exploration-class missions, sensorimotor disturbances may lead to disruption in the ability to ambulate and perform functional tasks during the initial introduction to a novel gravitational environment following a landing on a planetary surface. The overall goal of our current project is to develop a sensorimotor adaptability training program to facilitate rapid adaptation to these environments. We have developed a unique training system comprised of a treadmill placed on a motion-base facing a virtual visual scene. It provides an unstable walking surface combined with incongruent visual flow designed to enhance sensorimotor adaptability. Greater metabolic cost incurred during balance instability means more physical work is required during adaptation to new environments possibly affecting crewmembers? ability to perform mission critical tasks during early surface operations on planetary expeditions. The goal of this study was to characterize adaptation to a discordant sensory challenge across a number of performance modalities including locomotor stability, multi-tasking ability and metabolic cost. METHODS: Subjects (n=15) walked (4.0 km/h) on a treadmill for an 8 -minute baseline walking period followed by 20-minutes of walking (4.0 km/h) with support surface motion (0.3 Hz, sinusoidal lateral motion, peak amplitude 25.4 cm) provided by the treadmill/motion-base system. Stride frequency and auditory reaction time were collected as measures of locomotor stability and multi-tasking ability, respectively. Metabolic data (VO2) were collected via a portable metabolic gas analysis system. RESULTS: At the onset of lateral support surface motion, subj ects walking on our treadmill showed an increase in stride frequency and auditory reaction time indicating initial balance and multi-tasking disturbances. During the 20-minute adaptation period, balance control and multi-tasking performance improved. Similarly, throughout the 20-minute adaptation period, VO2 gradually

Elevated copper levels during larval development cause altered locomotor behavior in the adult carabid beetle Pterostichus cupreus L. (Coleoptera: Carbidae)

DEFF Research Database (Denmark)

Bayley, M; Baatrup, E; Heimbach, U

1995-01-01

It is generally believed that copper causes changes in carabid communities indirectly by reducing food availability, because these animals are frequently found to have only slightly elevated metal contents even close to pollution sources. Using computer-centered video tracking, the locomotor......, but not to effect the emergence weights of adults of either sex. This toxic effect on the larvae was preserved through pupation to the surviving adults, which were normal in size and appearance, but displayed a dramatically depressed locomotor behavior. Copper analysis of these adults revealed that copper levels...

Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice

DEFF Research Database (Denmark)

Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

2011-01-01

these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three...... to that of wild-type mice. The use of telemetric devices to measure circadian locomotor activity, temperature, and heart rate, together with the classical determination of circadian rhythms of wheel-running activity, raises questions about how representative wheel-running activity may be of other behavioral...

Phenotypic characterization of speed-associated gait changes in mice reveals modular organization of locomotor networks

DEFF Research Database (Denmark)

Bellardita, Carmelo; Kiehn, Ole

2015-01-01

behavioral outcomes expressed at different speeds of locomotion. Here, we use detailed kinematic analyses to search for signatures of a modular organization of locomotor circuits in intact and genetically modified mice moving at different speeds of locomotion. We show that wild-type mice display three...... distinct gaits: two alternating, walk and trot, and one synchronous, bound. Each gait is expressed in distinct ranges of speed with phenotypic inter-limb and intra-limb coordination. A fourth gait, gallop, closely resembled bound in most of the locomotor parameters but expressed diverse inter......-limb coordination. Genetic ablation of commissural V0V neurons completely removed the expression of one alternating gait, trot, but left intact walk, gallop, and bound. Ablation of commissural V0V and V0D neurons led to a loss of walk, trot, and gallop, leaving bound as the default gait. Our study provides...

Dynamics of vendor innovation capability: Evidence from the Electronics Manufacturing Services industry

DEFF Research Database (Denmark)

Perunovic, Zoran; Mefford, Robert; Christoffersen, Mads

2012-01-01

and innovation. The first is the realization that vendor capabilities have been recognized as one of the most important factors for the success of outsourcing. The second refers to the fact that, even though innovation capability is required, vendors are still being selected, and their performance evaluated......, by traditional manufacturing capabilities, such as cost, quality, delivery, and flexibility. Taking a vendor’s perspective in outsourcing, we develop and present a conceptual framework for studying vendor innovation capability. We propose to test this framework in the Electronic Manufacturing Services Industry....

Impaired terrestrial and arboreal locomotor performance in the western fence lizard (Sceloporus occidentalis) after exposure to an AChE-inhibiting pesticide

International Nuclear Information System (INIS)

DuRant, Sarah E.; Hopkins, William A.; Talent, Larry G.

2007-01-01

We examined the effects of a commonly used AChE-inhibiting pesticide on terrestrial and arboreal sprint performance, important traits for predator avoidance and prey capture, in the western fence lizard (Sceloporus occidentalis). Lizards were exposed to carbaryl (2.5, 25, and 250 μg/g) and were raced before and 4, 24, and 96 h after dosing. In the terrestrial setting, exposure to low concentrations of carbaryl had stimulatory effects on performance, but exposure to the highest concentration was inhibitory. No stimulatory effects of carbaryl were noted in the arboreal environment and performance in lizards was reduced after exposure to both the medium and highest dose of carbaryl. Our findings suggest that acute exposure to high concentrations of carbaryl can have important sublethal consequences on fitness-related traits in reptiles and that arboreal locomotor performance is a more sensitive indicator of AChE-inhibiting pesticide poisoning than terrestrial locomotor performance. - Exposure to an acetylcholinesterase-inhibiting pesticide alters locomotor performance in western fence lizards

Impaired terrestrial and arboreal locomotor performance in the western fence lizard (Sceloporus occidentalis) after exposure to an AChE-inhibiting pesticide

Energy Technology Data Exchange (ETDEWEB)

DuRant, Sarah E. [Wildlife Ecotoxicology and Physiological Ecology Program, Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, 444 Latham Hall, Blacksburg, VA 24061 (United States); University of Georgia, Savannah River Ecology Laboratory, PO Drawer E, Aiken, SC 29802 (United States); Hopkins, William A. [Wildlife Ecotoxicology and Physiological Ecology Program, Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, 444 Latham Hall, Blacksburg, VA 24061 (United States) and University of Georgia, Savannah River Ecology Laboratory, PO Drawer E, Aiken, SC 29802 (United States)]. E-mail: hopkinsw@vt.edu; Talent, Larry G. [Department of Zoology, Oklahoma State University, Stillwater, OK 74078 (United States)

2007-09-15

We examined the effects of a commonly used AChE-inhibiting pesticide on terrestrial and arboreal sprint performance, important traits for predator avoidance and prey capture, in the western fence lizard (Sceloporus occidentalis). Lizards were exposed to carbaryl (2.5, 25, and 250 {mu}g/g) and were raced before and 4, 24, and 96 h after dosing. In the terrestrial setting, exposure to low concentrations of carbaryl had stimulatory effects on performance, but exposure to the highest concentration was inhibitory. No stimulatory effects of carbaryl were noted in the arboreal environment and performance in lizards was reduced after exposure to both the medium and highest dose of carbaryl. Our findings suggest that acute exposure to high concentrations of carbaryl can have important sublethal consequences on fitness-related traits in reptiles and that arboreal locomotor performance is a more sensitive indicator of AChE-inhibiting pesticide poisoning than terrestrial locomotor performance. - Exposure to an acetylcholinesterase-inhibiting pesticide alters locomotor performance in western fence lizards.

Glucosamine-containing supplement improves locomotor functions in subjects with knee pain: a randomized, double-blind, placebo-controlled study.

Science.gov (United States)

Kanzaki, Noriyuki; Ono, Yoshiko; Shibata, Hiroshi; Moritani, Toshio

2015-01-01

The aim of this study was to investigate the ability of a glucosamine-containing supplement to improve locomotor functions in subjects with knee pain. A randomized, double-blind, placebo-controlled, parallel-group comparative study was conducted for 16 weeks in 100 Japanese subjects (age, 51.8±0.8 years) with knee pain. Subjects were randomly assigned to one of the two supplements containing 1) 1,200 mg of glucosamine hydrochloride, 60 mg of chondroitin sulfate, 45 mg of type II collagen peptides, 90 mg of quercetin glycosides, 10 mg of imidazole peptides, and 5 μg of vitamin D per day (GCQID group, n=50) or 2) a placebo (placebo group, n=50). Japanese Knee Osteoarthritis Measure, visual analog scale score, normal walking speed, and knee-extensor strength were measured to evaluate the effects of the supplement on knee-joint functions and locomotor functions. In subjects eligible for efficacy assessment, there was no significant group × time interaction, and there were improvements in knee-joint functions and locomotor functions in both groups, but there was no significant difference between the groups. In subjects with mild-to-severe knee pain at baseline, knee-extensor strength at week 8 (104.6±5.0% body weight vs 92.3±5.5% body weight, P=0.030) and the change in normal walking speed at week 16 (0.11±0.03 m/s vs 0.05±0.02 m/s, P=0.038) were significantly greater in the GCQID group than in the placebo group. Further subgroup analysis based on Kellgren-Lawrence (K-L) grade showed that normal walking speed at week 16 (1.36±0.05 m/s vs 1.21±0.02 m/s, Pknee pain, GCQID supplementation was effective for relieving knee pain and improving locomotor functions.

Impairment of locomotor activity induced by the novel N-acylhydrazone derivatives LASSBio-785 and LASSBio-786 in mice

Directory of Open Access Journals (Sweden)

G.A.P. Silva

Full Text Available The N-acylhydrazone (NAH analogues N-methyl 2-thienylidene 3,4-benzoylhydrazine (LASSBio-785 and N-benzyl 2-thienylidene 3,4-benzoylhydrazine (LASSBio-786 were prepared from 2-thienylidene 3,4-methylenedioxybenzoylhydrazine (LASSBio-294. The ability of LASSBio-785 and LASSBio-786 to decrease central nervous system activity was investigated in male Swiss mice. LASSBio-785 or LASSBio-786 (30 mg/kg, ip reduced locomotor activity from 209 ± 26 (control to 140 ± 18 (P < 0.05 or 146 ± 15 crossings/min (P < 0.05, respectively. LASSBio-785 (15 or 30 mg/kg, iv also reduced locomotor activity from 200 ± 15 to 116 ± 29 (P < 0.05 or 60 ± 16 crossings/min (P < 0.01, respectively. Likewise, LASSBio-786 (15 or 30 mg/kg, iv reduced locomotor activity from 200 ± 15 to 127 ± 10 (P < 0.01 or 96 ± 14 crossings/min (P < 0.01, respectively. Pretreatment with flumazenil (20 mg/kg, ip prevented the locomotor impairment induced by NAH analogues (15 mg/kg, iv, providing evidence that the benzodiazepine (BDZ receptor is involved. This finding was supported by the structural similarity of NAH analogues to midazolam. However, LASSBio-785 showed weak binding to the BDZ receptor. LASSBio-785 or LASSBio-786 (30 mg/kg, ip, n = 10 increased pentobarbital-induced sleeping time from 42 ± 5 (DMSO to 66 ± 6 (P < 0.05 or 75 ± 4 min (P < 0.05, respectively. The dose required to achieve 50% hypnosis (HD50 following iv injection of LASSBio-785 or LASSBio-786 was 15.8 or 9.5 mg/kg, respectively. These data suggest that both NAH analogues might be useful for the development of new neuroactive drugs for the treatment of insomnia or for use in conjunction with general anesthesia.

Impairment of locomotor activity induced by the novel N-acylhydrazone derivatives LASSBio-785 and LASSBio-786 in mice

Energy Technology Data Exchange (ETDEWEB)

Silva, G.A.P. [Programa de Desenvolvimento de Fármacos, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Kummerle, A.E. [Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio), Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Antunes, F. [Programa de Desenvolvimento de Fármacos, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Fraga, C.A.M.; Barreiro, E.J. [Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio), Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Zapata-Sudo, G.; Sudo, R.T. [Programa de Desenvolvimento de Fármacos, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

2013-03-19

The N-acylhydrazone (NAH) analogues N-methyl 2-thienylidene 3,4-benzoylhydrazine (LASSBio-785) and N-benzyl 2-thienylidene 3,4-benzoylhydrazine (LASSBio-786) were prepared from 2-thienylidene 3,4-methylenedioxybenzoylhydrazine (LASSBio-294). The ability of LASSBio-785 and LASSBio-786 to decrease central nervous system activity was investigated in male Swiss mice. LASSBio-785 or LASSBio-786 (30 mg/kg, ip) reduced locomotor activity from 209 ± 26 (control) to 140 ± 18 (P < 0.05) or 146 ± 15 crossings/min (P < 0.05), respectively. LASSBio-785 (15 or 30 mg/kg, iv) also reduced locomotor activity from 200 ± 15 to 116 ± 29 (P < 0.05) or 60 ± 16 crossings/min (P < 0.01), respectively. Likewise, LASSBio-786 (15 or 30 mg/kg, iv) reduced locomotor activity from 200 ± 15 to 127 ± 10 (P < 0.01) or 96 ± 14 crossings/min (P < 0.01), respectively. Pretreatment with flumazenil (20 mg/kg, ip) prevented the locomotor impairment induced by NAH analogues (15 mg/kg, iv), providing evidence that the benzodiazepine (BDZ) receptor is involved. This finding was supported by the structural similarity of NAH analogues to midazolam. However, LASSBio-785 showed weak binding to the BDZ receptor. LASSBio-785 or LASSBio-786 (30 mg/kg, ip, n = 10) increased pentobarbital-induced sleeping time from 42 ± 5 (DMSO) to 66 ± 6 (P < 0.05) or 75 ± 4 min (P < 0.05), respectively. The dose required to achieve 50% hypnosis (HD{sub 50}) following iv injection of LASSBio-785 or LASSBio-786 was 15.8 or 9.5 mg/kg, respectively. These data suggest that both NAH analogues might be useful for the development of new neuroactive drugs for the treatment of insomnia or for use in conjunction with general anesthesia.

Impairment of locomotor activity induced by the novel N-acylhydrazone derivatives LASSBio-785 and LASSBio-786 in mice

International Nuclear Information System (INIS)

Silva, G.A.P.; Kummerle, A.E.; Antunes, F.; Fraga, C.A.M.; Barreiro, E.J.; Zapata-Sudo, G.; Sudo, R.T.

2013-01-01

The N-acylhydrazone (NAH) analogues N-methyl 2-thienylidene 3,4-benzoylhydrazine (LASSBio-785) and N-benzyl 2-thienylidene 3,4-benzoylhydrazine (LASSBio-786) were prepared from 2-thienylidene 3,4-methylenedioxybenzoylhydrazine (LASSBio-294). The ability of LASSBio-785 and LASSBio-786 to decrease central nervous system activity was investigated in male Swiss mice. LASSBio-785 or LASSBio-786 (30 mg/kg, ip) reduced locomotor activity from 209 ± 26 (control) to 140 ± 18 (P < 0.05) or 146 ± 15 crossings/min (P < 0.05), respectively. LASSBio-785 (15 or 30 mg/kg, iv) also reduced locomotor activity from 200 ± 15 to 116 ± 29 (P < 0.05) or 60 ± 16 crossings/min (P < 0.01), respectively. Likewise, LASSBio-786 (15 or 30 mg/kg, iv) reduced locomotor activity from 200 ± 15 to 127 ± 10 (P < 0.01) or 96 ± 14 crossings/min (P < 0.01), respectively. Pretreatment with flumazenil (20 mg/kg, ip) prevented the locomotor impairment induced by NAH analogues (15 mg/kg, iv), providing evidence that the benzodiazepine (BDZ) receptor is involved. This finding was supported by the structural similarity of NAH analogues to midazolam. However, LASSBio-785 showed weak binding to the BDZ receptor. LASSBio-785 or LASSBio-786 (30 mg/kg, ip, n = 10) increased pentobarbital-induced sleeping time from 42 ± 5 (DMSO) to 66 ± 6 (P < 0.05) or 75 ± 4 min (P < 0.05), respectively. The dose required to achieve 50% hypnosis (HD 50 ) following iv injection of LASSBio-785 or LASSBio-786 was 15.8 or 9.5 mg/kg, respectively. These data suggest that both NAH analogues might be useful for the development of new neuroactive drugs for the treatment of insomnia or for use in conjunction with general anesthesia

Buoyancy under control: underwater locomotor performance in a deep diving seabird suggests respiratory strategies for reducing foraging effort.

Directory of Open Access Journals (Sweden)

Timothée R Cook

Full Text Available BACKGROUND: Because they have air stored in many body compartments, diving seabirds are expected to exhibit efficient behavioural strategies for reducing costs related to buoyancy control. We study the underwater locomotor activity of a deep-diving species from the Cormorant family (Kerguelen shag and report locomotor adjustments to the change of buoyancy with depth. METHODOLOGY/PRINCIPAL FINDINGS: Using accelerometers, we show that during both the descent and ascent phases of dives, shags modelled their acceleration and stroking activity on the natural variation of buoyancy with depth. For example, during the descent phase, birds increased swim speed with depth. But in parallel, and with a decay constant similar to the one in the equation explaining the decrease of buoyancy with depth, they decreased foot-stroke frequency exponentially, a behaviour that enables birds to reduce oxygen consumption. During ascent, birds also reduced locomotor cost by ascending passively. We considered the depth at which they started gliding as a proxy to their depth of neutral buoyancy. This depth increased with maximum dive depth. As an explanation for this, we propose that shags adjust their buoyancy to depth by varying the amount of respiratory air they dive with. CONCLUSIONS/SIGNIFICANCE: Calculations based on known values of stored body oxygen volumes and on deep-diving metabolic rates in avian divers suggest that the variations of volume of respiratory oxygen associated with a respiration mediated buoyancy control only influence aerobic dive duration moderately. Therefore, we propose that an advantage in cormorants--as in other families of diving seabirds--of respiratory air volume adjustment upon diving could be related less to increasing time of submergence, through an increased volume of body oxygen stores, than to reducing the locomotor costs of buoyancy control.

Gait quality is improved by locomotor training in individuals with SCI regardless of training approach

NARCIS (Netherlands)

Nooijen, C.F.J.; ter Hoeve, N.; Field-Fote, E.C.

2009-01-01

Background: While various body weight supported locomotor training (BWSLT) approaches are reported in the literature for individuals with spinal cord injury (SCI), none have evaluated outcomes in terms of gait quality. The purpose of this study was to compare changes in measures of gait quality

Competing on capabilities: the new rules of corporate strategy.

Science.gov (United States)

Stalk, G; Evans, P; Shulman, L E

1992-01-01

In the 1980s, companies discovered time as a new source of competitive advantage. In the 1990s, they will discover that time is only one piece of a more far-reaching transformation in the logic of competition. Using examples from Wal-Mart and other highly successful companies, Stalk, Evans, and Shulman of the Boston Consulting Group provide managers with a guide to the new world of "capabilities-based competition." In today's dynamic business environment, strategy too must become dynamic. Competition is a "war of movement" in which success depends on anticipation of market trends and quick response to changing customer needs. In such an environment, the essence of strategy is not the structure of a company's products and markets but the dynamics of its behavior. To succeed, a company must weave its key business processes into hard-to-imitate strategic capabilities that distinguish it from its competitors in the eyes of customers. A capability is a set of business processes strategically understood--for example, Wal-Mart's expertise in inventory replenishment, Honda's skill at dealer management, or Banc One's ability to "out-local the national banks and out-national the local banks." Such capabilities are collective and cross-functional--a small part of many people's jobs, not a large part of a few. Finally, competing on capabilities requires strategic investments in support systems that span traditional SBUs and functions and go far beyond what traditional cost-benefit metrics can justify. A CEO's success in building and managing a company's capabilities will be the chief test of management skill in the 1990s. The prize: companies that combine scale and flexibility to outperform the competition.

Effects of repeated exposure to malathion on growth, food consumption, and locomotor performance of the western fence lizard (Sceloporus occidentalis)

International Nuclear Information System (INIS)

Holem, Ryan R.; Hopkins, William A.; Talent, Larry G.

2008-01-01

Effects of repeated pollutant exposure on growth, locomotor performance, and behavior have rarely been evaluated in reptiles. We administered three doses of malathion (2.0, 20, or 100 mg/kg body weight) to western fence lizards (Sceloporus occidentalis) over an 81 day period. Eight and 23% mortality occurred at 20 and 100 mg/kg (p = 0.079) and 85% of lizards in the 100 mg/kg group exhibited clinical symptoms of poisoning. Growth, food consumption, body condition index, and terrestrial locomotor performance were not significantly influenced by malathion. However, arboreal sprint velocity was significantly reduced in lizards receiving 100 mg/kg. Fifty percent of lizards in the 100 mg/kg group also refused to sprint in the arboreal setting (p = 0.085). Based on these results, arboreal locomotor performance was the most sensitive metric of exposure we evaluated. Further study of compounds such as malathion is warranted due to highly variable application rates and exposure scenarios. - Repeated exposure of western fence lizards to malathion caused reduced arboreal performance and some mortality but growth, food consumption, and terrestrial performance were not affected

Effects of repeated exposure to malathion on growth, food consumption, and locomotor performance of the western fence lizard (Sceloporus occidentalis)

Energy Technology Data Exchange (ETDEWEB)

Holem, Ryan R. [University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29801 (United States); ENTRIX, Inc., Okemos, MI 48864 (United States); Hopkins, William A. [University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29801 (United States); Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)], E-mail: hopkinsw@vt.edu; Talent, Larry G. [Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK 74078 (United States)

2008-03-15

Effects of repeated pollutant exposure on growth, locomotor performance, and behavior have rarely been evaluated in reptiles. We administered three doses of malathion (2.0, 20, or 100 mg/kg body weight) to western fence lizards (Sceloporus occidentalis) over an 81 day period. Eight and 23% mortality occurred at 20 and 100 mg/kg (p = 0.079) and 85% of lizards in the 100 mg/kg group exhibited clinical symptoms of poisoning. Growth, food consumption, body condition index, and terrestrial locomotor performance were not significantly influenced by malathion. However, arboreal sprint velocity was significantly reduced in lizards receiving 100 mg/kg. Fifty percent of lizards in the 100 mg/kg group also refused to sprint in the arboreal setting (p = 0.085). Based on these results, arboreal locomotor performance was the most sensitive metric of exposure we evaluated. Further study of compounds such as malathion is warranted due to highly variable application rates and exposure scenarios. - Repeated exposure of western fence lizards to malathion caused reduced arboreal performance and some mortality but growth, food consumption, and terrestrial performance were not affected.

Capabilities, innovation, and overall performance in Brazilian export firms.

Directory of Open Access Journals (Sweden)

José Ednilson de Oliveira Cabral

2015-06-01

Full Text Available This article extends the current research on innovation by investigating the relationship between innovative capabilities and export firms’ overall performance. From the perspectives of the resource-based view (RBV and dynamic capability, we examine the differential and interactive effects of exploration and exploitation capabilities in product innovation for external markets and overall performance (direct and mediated by a new product. In addition, we test the moderating effect of market dynamism and the controlling effect of firm size on these relationships. Hence, the main contribution of this article is developing and empirically testing an original model, by combining these constructs that address new relationships, in an emerging country. This model was tested with data from 498 Brazilian export firms, distributed throughout all Brazilian manufacturing sectors, by firm size, and in states. The analysis was made with application of the structural equation modeling (SEM. As a result, we found support for the assumptions that exploitation capabilities influence product innovation and overall performance, whereas exploration capabilities and their interaction to exploitation capabilities influence overall performance, but not product innovation. Additionally, the relationship between exploitation capabilities and overall performance is mediated by product innovation. Unlike hypothesized, market dynamism does not moderate the relationship between product innovation and overall performance. Furthermore, firm size works as a controlling variable in the relationships analyzed. Regarding the implications for theory, this study contributes to grasp that exploitation capabilities influences a firm’s overall performance, both directly and indirectly (via product innovation, and highlights the various direct and mediatory effects of innovation on overall performance. These insights show the importance of considering the role of mediating and

Activation of the GABAB receptor prevents nicotine-induced locomotor stimulation in mice

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Carla eLobina

2011-12-01

Full Text Available Recent studies demonstrated that activation of the GABAB receptor, either by means of orthosteric agonists or positive allosteric modulators (PAMs, inhibited different nicotine-related behaviors, including intravenous self-administration and conditioned place preference, in rodents. The present study investigated whether the anti-nicotine effects of the GABAB receptor agonist, baclofen, and GABAB PAMs, CGP7930 and GS39783, extend to nicotine stimulant effects. To this end, CD1 mice were initially treated with baclofen (0, 1.25, and 2.5 mg/kg, i.p., CGP7930 (0, 25, and 50 mg/kg, i.g., or GS39783 (0, 25, and 50 mg/kg, i.g., then treated with nicotine (0 and 0.05 mg/kg, s.c., and finally exposed to an automated apparatus for recording of locomotor activity. Pretreatment with doses of baclofen, CGP7930, or GS39783 that did not alter locomotor activity when given with nicotine vehicle fully prevented hyperlocomotion induced by 0.05 mg/kg nicotine. These data extend to nicotine stimulant effects the capacity of baclofen and GABAB PAMs to block the reinforcing, motivational, and rewarding properties of nicotine. These data strengthen the hypothesis that activation of the GABAB receptor may represent a potentially useful, anti-smoking therapeutic strategy.

Regulation by orexin of feeding behaviour and locomotor activity in the goldfish.

Science.gov (United States)

Nakamachi, T; Matsuda, K; Maruyama, K; Miura, T; Uchiyama, M; Funahashi, H; Sakurai, T; Shioda, S

2006-04-01

Orexin is a hypothalamic neuropeptide that is implicated in the regulation of feeding behaviour and the sleep-wakefulness cycle in mammals. However, in spite of a growing body of knowledge concerning orexin in mammals, the orexin system and its function have not been well studied in lower vertebrates. In the present study, we first examined the effect of feeding status on the orexin-like immunoreactivity (orexin-LI) and the expression of orexin mRNA in the goldfish brain. The number of cells showing orexin-LI in the hypothalamus of goldfish brain showed a significant increase in fasted fish and a significant decrease in glucose-injected fish. The expression level of orexin mRNA in the brains of fasted fish increased compared to that of fed fish. We also examined the effect of an i.c.v. injection of orexin or an anti-orexin serum on food intake and locomotor activity in the goldfish. Administration of orexin by i.c.v. injection induced a significant increase of food intake and locomotor activity, whereas i.p. injection of glucose or i.c.v. injection of anti-orexin serum decreased food consumption. These results indicate that the orexin functions as an orexigenic factor in the goldfish brain.

Dynamic Capabilities Associated with a Firm’s Growth in Developing Countries. A Comparative Study of Argentinean SMEs in the Software and Tourism Industries

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Claudia D’Annunzio

2015-01-01

Full Text Available Although recent evidence suggests that the development of dynamic capabilities (DC is a key factor to gain and sustain competitive advantages to promote firm ́s growth, the question of how SMEs create, identify, and seize opportunities for growth have not been fully explored, particularly in developing countries with scarce resources. The aim of this study is to shed light on how SMEs develop capabilities to grow in the specific context of developing countries with resources constraints. To achieve a detailed description of the processes involved, this study applies a qualitative methodology based on a comparative case study of eight SMEs within the software and tourism industries in Argentine, which have been previously identified as dynamic sectors with high growth potential. Our findings suggest that SMEs develop DC mainly through an emerging process of iterative experimentation rather than through strategic planning. This process involves the coordination of organizational actions and resources, with managers playing a key role.

Effects of Resveratrol on Daily Rhythms of Locomotor Activity and Body Temperature in Young and Aged Grey Mouse Lemurs

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Fabien Pifferi

2013-01-01

Full Text Available In several species, resveratrol, a polyphenolic compound, activates sirtuin proteins implicated in the regulation of energy balance and biological clock processes. To demonstrate the effect of resveratrol on clock function in an aged primate, young and aged mouse lemurs (Microcebus murinus were studied over a 4-week dietary supplementation with resveratrol. Spontaneous locomotor activity and daily variations in body temperature were continuously recorded. Reduction in locomotor activity onset and changes in body temperature rhythm in resveratrol-supplemented aged animals suggest an improved synchronisation on the light-dark cycle. Resveratrol could be a good candidate to restore the circadian rhythms in the elderly.

Locomotor sequence learning in visually guided walking

DEFF Research Database (Denmark)

Choi, Julia T; Jensen, Peter; Nielsen, Jens Bo

2016-01-01

walking. In addition, we determined how age (i.e., healthy young adults vs. children) and biomechanical factors (i.e., walking speed) affected the rate and magnitude of locomotor sequence learning. The results showed that healthy young adults (age 24 ± 5 years, N = 20) could learn a specific sequence...... of step lengths over 300 training steps. Younger children (age 6-10 years, N = 8) have lower baseline performance, but their magnitude and rate of sequence learning was the same compared to older children (11-16 years, N = 10) and healthy adults. In addition, learning capacity may be more limited...... to modify step length from one trial to the next. Our sequence learning paradigm is derived from the serial reaction-time (SRT) task that has been used in upper limb studies. Both random and ordered sequences of step lengths were used to measure sequence-specific and sequence non-specific learning during...

Effects of Lactuca sativa extract on exploratory behavior pattern, locomotor activity and anxiety in mice

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S.N. Harsha

2012-05-01

Full Text Available Objective: To evaluate antianxiety property of Lactuca sativa, an important and commonly used leafy vegetable known for its medicinal properties belongs to Asteraceae family. Methods: Elevated plus maze (EPM, open field test (OFT, rat exposure test, hyponeophagia and marble burying test were performed in mice models to assess the exploratory behaviour and to assess anxiolytic property of hydro-alcohol extract of Lactuca sativa. Diazepam (1 mg/kg body wt. served as the standard anxiolytic agent for all the tests. The dried extract of the plant leaf in doses of 100, 200 and 400 mg/kg body weight was administered orally to mice for duration of 15 or 30 days and evaluated exploratory behaviour, locomotor and anxiolytic activities. Results: Time spent and number of entries into the open arm was measured in EPM followed by total locomotor activity in OFT and latency to enter the food zone in hyponeophagia. Conclusions: The study suggested that hydro-alcohol extract of Lactuca sativa leaves possess potent anxiolytic property.

Sexual differences in post-hatching Saunders's gulls: size, locomotor activity, and foraging skill.

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Yoon, Jongmin; Lee, Seung-Hee; Joo, Eun-Jin; Na, Ki-Jeong; Park, Shi-Ryong

2013-04-01

Various selection pressures induce the degree and direction of sexual size dimorphism in animals. Selection favors either larger males for contests over mates or resources, or smaller males are favored for maneuverability; whereas larger females are favored for higher fecundity, or smaller females for earlier maturation for reproduction. In the genus of Larus (seagulls), adult males are generally known to be larger in size than adult females. However, the ontogeny of sexual size dimorphism is not well understood, compared to that in adults. The present study investigates the ontogeny of sexual size dimorphism in Saunders's gulls (Larus saundersi) in captivity. We artificially incubated fresh eggs collected in Incheon, South Korea, and measured body size, locomotor activity, and foraging skill in post-hatching chicks in captivity. Our results indicated that the sexual differences in size and locomotor activity occurred with the post-hatching development. Also, larger males exhibited greater foraging skills for food acquisition than smaller females at 200 days of age. Future studies should assess how the adaptive significance of the sexual size dimorphism in juveniles is linked with sexual divergence in survival rates, intrasexual contests, or parental effort in sexes.

Sherlock Holmes and the Curious Case of the Human Locomotor Central Pattern Generator.

Science.gov (United States)

Klarner, Taryn; Zehr, E Paul

2018-03-14

Evidence first described in reduced animal models over 100 years ago led to deductions about the control of locomotion through spinal locomotor central pattern generating (CPG) networks. These discoveries in nature were contemporaneous with another form of deductive reasoning found in popular culture-that of Arthur Conan Doyle's detective "Sherlock Holmes". Since the invasive methods used in reduced non-human animal preparations are not amenable to study in humans, we are left instead with deducing from other measures and observations. Using the deductive reasoning approach of Sherlock Holmes as a metaphor for framing research into human CPGs, we speculate and weigh the evidence that should be observable in humans based on knowledge from other species. This review summarizes indirect inference to assess "observable evidence" of pattern generating activity which leads to the logical deduction of CPG contributions to arm and leg activity during locomotion in humans. The question of where a CPG may be housed in the human nervous system remains incompletely resolved at this time. Ongoing understanding, elaboration and application of functioning locomotor CPGs in humans is important for gait rehabilitation strategies in those with neurological injuries.

Enkephalin and dynorphin neuropeptides are differently correlated with locomotor hypersensitivity and levodopa-induced dyskinesia in parkinsonian rats.

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Sgroi, Stefania; Capper-Loup, Christine; Paganetti, Paolo; Kaelin-Lang, Alain

2016-06-01

The opioidergic neuropeptides dynorphin (DYN) and enkephalin (ENK) and the D1 and D2 dopaminergic receptors (D1R, D2R) are involved in the striatal control of motor and behavioral function. In Parkinson's disease, motor disturbances such as "on-off" motor fluctuations and involuntary movements (dyskinesia) are severe complications that often arise after chronic l-dihydroxyphenylalanine (l-DOPA) treatment. Changes in the striatal expression of preproENK (PPENK), proDYN (PDYN), D1R, and D2R mRNA have been observed in parkinsonian animals treated with l-DOPA. Enhanced opioidergic transmission has been found in association with l-DOPA-induced dyskinesia, but the connection of PPENK, PDYN, D1R, and D2R mRNA expression with locomotor activity remains unclear. In this study, we measured PPENK, PDYN, D1R and D2R mRNA levels by in situ hybridization in the striatum of 6-OHDA hemi-parkinsonian rats treated with l-DOPA (PD+l-DOPA group), along with two control groups (PD+saline and naive+l-DOPA). We found different levels of expression of PPENK, PDYN, D1R and D2R mRNA across the experimental groups and correlated the changes in mRNA expression with dyskinesia and locomotor variables assessed by open field test during several phases of l-DOPA treatment. Both PDYN and PPENK mRNA levels were correlated with the severity of dyskinesia, while PPENK mRNA levels were also correlated with the frequency of contralateral rotational movements and with locomotor variables. Moreover, a strong correlation was found between D1R mRNA expression and D2R mRNA expression in the PD+l-DOPA group. These findings suggest that, in parkinsonian animals treated with l-DOPA, high levels of PPENK are a prerequisite for a locomotor sensitization to l-DOPA treatment, while PDYN overexpression is responsible only for the development of dyskinesia. Copyright © 2016 Elsevier Inc. All rights reserved.

Swing Boat: Inducing and Recording Locomotor Activity in a Drosophila melanogaster Model of Alzheimer’s Disease

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Johannes Berlandi

2017-08-01

Full Text Available Recent studies indicate that physical activity can slow down progression of neurodegeneration in humans. To date, automated ways to induce activity have been predominantly described in rodent models. To study the impact of activity on behavior and survival in adult Drosophila melanogaster, we aimed to develop a rotating tube device “swing boat” which is capable of monitoring activity and sleep patterns as well as survival rates of flies. For the purpose of a first application, we tested our device on a transgenic fly model of Alzheimer’s disease (AD. Activity of flies was recorded in a climate chamber using the Drosophila Activity Monitoring (DAM System connected to data acquisition software. Locomotor activity was induced by a rotating tube device “swing boat” by repetitively tilting the tubes for 30 min per day. A non-exercising group of flies was used as control and activity and sleep patterns were obtained. The GAL4-/UAS system was used to drive pan-neuronal expression of human Aβ42 in flies. Immunohistochemical stainings for Aβ42 were performed on paraffin sections of adult fly brains. Daily rotation of the fly tubes evoked a pronounced peak of activity during the 30 min exercise period. Pan-neuronal expression of human Aβ42 in flies caused abnormalities in locomotor activity, reduction of life span and elevated sleep fragmentation in comparison to wild type flies. Furthermore, the formation of amyloid accumulations was observed in the adult fly brain. Gently induced activity over 12 days did not evoke prominent effects in wild type flies but resulted in prolongation of median survival time by 7 days (32.6% in Aβ42-expressing flies. Additionally, restoration of abnormally decreased night time sleep (10% and reduced sleep fragmentation (28% were observed compared to non-exercising Aβ42-expressing flies. On a structural level no prominent effects regarding prevalence of amyloid aggregations and Aβ42 RNA expression were

Adjustment of the dynamic weight distribution as a sensitive parameter for diagnosis of postural alteration in a rodent model of vestibular deficit.

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Brahim Tighilet

Full Text Available Vestibular disorders, by inducing significant posturo-locomotor and cognitive disorders, can significantly impair the most basic tasks of everyday life. Their precise diagnosis is essential to implement appropriate therapeutic countermeasures. Monitoring their evolution is also very important to validate or, on the contrary, to adapt the undertaken therapeutic actions. To date, the diagnosis methods of posturo-locomotor impairments are restricted to examinations that most often lack sensitivity and precision. In the present work we studied the alterations of the dynamic weight distribution in a rodent model of sudden and complete unilateral vestibular loss. We used a system of force sensors connected to a data analysis system to quantify in real time and in an automated way the weight bearing of the animal on the ground. We show here that sudden, unilateral, complete and permanent loss of the vestibular inputs causes a severe alteration of the dynamic ground weight distribution of vestibulo lesioned rodents. Characteristics of alterations in the dynamic weight distribution vary over time and follow the sequence of appearance and disappearance of the various symptoms that compose the vestibular syndrome. This study reveals for the first time that dynamic weight bearing is a very sensitive parameter for evaluating posturo-locomotor function impairment. Associated with more classical vestibular examinations, this paradigm can considerably enrich the methods for assessing and monitoring vestibular disorders. Systematic application of this type of evaluation to the dizzy or unstable patient could improve the detection of vestibular deficits and allow predicting better their impact on posture and walk. Thus it could also allow a better follow-up of the therapeutic approaches for rehabilitating gait and balance.

Adjustment of the dynamic weight distribution as a sensitive parameter for diagnosis of postural alteration in a rodent model of vestibular deficit.

Science.gov (United States)

Tighilet, Brahim; Péricat, David; Frelat, Alais; Cazals, Yves; Rastoldo, Guillaume; Boyer, Florent; Dumas, Olivier; Chabbert, Christian

2017-01-01

Vestibular disorders, by inducing significant posturo-locomotor and cognitive disorders, can significantly impair the most basic tasks of everyday life. Their precise diagnosis is essential to implement appropriate therapeutic countermeasures. Monitoring their evolution is also very important to validate or, on the contrary, to adapt the undertaken therapeutic actions. To date, the diagnosis methods of posturo-locomotor impairments are restricted to examinations that most often lack sensitivity and precision. In the present work we studied the alterations of the dynamic weight distribution in a rodent model of sudden and complete unilateral vestibular loss. We used a system of force sensors connected to a data analysis system to quantify in real time and in an automated way the weight bearing of the animal on the ground. We show here that sudden, unilateral, complete and permanent loss of the vestibular inputs causes a severe alteration of the dynamic ground weight distribution of vestibulo lesioned rodents. Characteristics of alterations in the dynamic weight distribution vary over time and follow the sequence of appearance and disappearance of the various symptoms that compose the vestibular syndrome. This study reveals for the first time that dynamic weight bearing is a very sensitive parameter for evaluating posturo-locomotor function impairment. Associated with more classical vestibular examinations, this paradigm can considerably enrich the methods for assessing and monitoring vestibular disorders. Systematic application of this type of evaluation to the dizzy or unstable patient could improve the detection of vestibular deficits and allow predicting better their impact on posture and walk. Thus it could also allow a better follow-up of the therapeutic approaches for rehabilitating gait and balance.

Extending the Capabilities of the Mooring Analysis Program: A Survey of Dynamic Mooring Line Theories for Integration into FAST: Preprint

Energy Technology Data Exchange (ETDEWEB)

Masciola, M.; Jonkman, J.; Robertson, A.

2014-03-01

Techniques to model dynamic mooring lines come in various forms. The most widely used models include either a heuristic representation of the physics (such as a Lumped-Mass, LM, system), a Finite-Element Analysis (FEA) discretization of the lines (discretized in space), or a Finite-Difference (FD) model (which is discretized in both space and time). In this paper, we explore the features of the various models, weigh the advantages of each, and propose a plan for implementing one dynamic mooring line model into the open-source Mooring Analysis Program (MAP). MAP is currently used as a module for the FAST offshore wind turbine computer-aided engineering (CAE) tool to model mooring systems quasi-statically, although dynamic mooring capabilities are desired. Based on the exploration in this manuscript, the lumped-mass representation is selected for implementation in MAP based on its simplicity, computational cost, and ability to provide similar physics captured by higher-order models.

Limb Bone Structural Proportions and Locomotor Behavior in A.L. 288-1 ("Lucy".

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Christopher B Ruff

Full Text Available While there is broad agreement that early hominins practiced some form of terrestrial bipedality, there is also evidence that arboreal behavior remained a part of the locomotor repertoire in some taxa, and that bipedal locomotion may not have been identical to that of modern humans. It has been difficult to evaluate such evidence, however, because of the possibility that early hominins retained primitive traits (such as relatively long upper limbs of little contemporaneous adaptive significance. Here we examine bone structural properties of the femur and humerus in the Australopithecus afarensis A.L. 288-1 ("Lucy", 3.2 Myr that are known to be developmentally plastic, and compare them with other early hominins, modern humans, and modern chimpanzees. Cross-sectional images were obtained from micro-CT scans of the original specimens and used to derive section properties of the diaphyses, as well as superior and inferior cortical thicknesses of the femoral neck. A.L. 288-1 shows femoral/humeral diaphyseal strength proportions that are intermediate between those of modern humans and chimpanzees, indicating more mechanical loading of the forelimb than in modern humans, and by implication, a significant arboreal locomotor component. Several features of the proximal femur in A.L. 288-1 and other australopiths, including relative femoral head size, distribution of cortical bone in the femoral neck, and cross-sectional shape of the proximal shaft, support the inference of a bipedal gait pattern that differed slightly from that of modern humans, involving more lateral deviation of the body center of mass over the support limb, which would have entailed increased cost of terrestrial locomotion. There is also evidence consistent with increased muscular strength among australopiths in both the forelimb and hind limb, possibly reflecting metabolic trade-offs between muscle and brain development during hominin evolution. Together these findings imply

Dynamic Boiler Performance

DEFF Research Database (Denmark)

Sørensen, Kim

Traditionally, boilers have been designed mainly focussing on the static operation of the plant. The dynamic capability has been given lower priority and the analysis has typically been limited to assuring that the plant was not over-stressed due to large temperature gradients. New possibilities...... developed. Analyzing boilers for dynamic operation gives rise to a number of opposing aims: shrinking and swelling, steam quality, stress levels, control system/philosophy, pressurization etc. Common for these opposing aims is that an optimum can be found for selected operation conditions. The framework has...... for buying and selling energy has increased the focus on the dynamic operation capability, efciency, emissions etc. For optimizing the design of boilers for dynamic operation a quantication of the dynamic capability is needed. A framework for optimizing design of boilers for dynamic operation has been...

Conceptualizing innovation capabilities: A contingency perspective

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Tor Helge Aas

2017-01-01

Full Text Available Empirical research has confirmed that a positive relationship exists between the implementation of innovation activities and the future performance of organizations. Firms utilize resources and capabilities to develop innovations in the form of new products, services or processes. Some firms prove to be better at reproducing innovation success than others, and the capacity to do so is referred to as innovation capability. However, the term innovation capability is ambiguously treated in extant literature. There are several different definitions of the concept and the distinction between innovation capabilities and other types of capabilities, such as dynamic capabilities, is neither explicitly stated, nor is the relationship between the concept and other resource- and capability-based concepts within strategy theory established. Although innovation is increasingly identified as crucial for a firm’s sustainable competitiveness in contemporary volatile and complex markets, the strategy-innovation link is underdeveloped in extant research. To overcome this challenge this paper raises the following research question: What type of innovation capabilities are required to innovate successfully? Due to the status of the extant research, we chose a conceptual research design to answer our research question and the paper contributes with a conceptual framework to discuss what innovation capabilities firms need to reproduce innovation success. Based on careful examination of current literature on innovation capability specifically, and the strategy-innovation link in general, we suggest that innovation capability must be viewed along two dimensions – innovation novelty and market characteristics. This framework enables the identification of four different contexts for innovation capabilities in a two-bytwo matrix. We discuss the types of innovation capabilities necessary within the four different contexts. This novel framework contributes to the

Poststroke Hemiparesis Impairs the Rate but not Magnitude of Adaptation of Spatial and Temporal Locomotor Features

Science.gov (United States)

Savin, Douglas N.; Tseng, Shih-Chiao; Whitall, Jill; Morton, Susanne M.

2015-01-01

Background Persons with stroke and hemiparesis walk with a characteristic pattern of spatial and temporal asymmetry that is resistant to most traditional interventions. It was recently shown in nondisabled persons that the degree of walking symmetry can be readily altered via locomotor adaptation. However, it is unclear whether stroke-related brain damage affects the ability to adapt spatial or temporal gait symmetry. Objective Determine whether locomotor adaptation to a novel swing phase perturbation is impaired in persons with chronic stroke and hemiparesis. Methods Participants with ischemic stroke (14) and nondisabled controls (12) walked on a treadmill before, during, and after adaptation to a unilateral perturbing weight that resisted forward leg movement. Leg kinematics were measured bilaterally, including step length and single-limb support (SLS) time symmetry, limb angle center of oscillation, and interlimb phasing, and magnitude of “initial” and “late” locomotor adaptation rates were determined. Results All participants had similar magnitudes of adaptation and similar initial adaptation rates both spatially and temporally. All 14 participants with stroke and baseline asymmetry temporarily walked with improved SLS time symmetry after adaptation. However, late adaptation rates poststroke were decreased (took more strides to achieve adaptation) compared with controls. Conclusions Mild to moderate hemiparesis does not interfere with the initial acquisition of novel symmetrical gait patterns in both the spatial and temporal domains, though it does disrupt the rate at which “late” adaptive changes are produced. Impairment of the late, slow phase of learning may be an important rehabilitation consideration in this patient population. PMID:22367915

Circadian locomotor rhythms in the cricket, Gryllodes sigillatus. I. Localization of the pacemaker and the photoreceptor.

Science.gov (United States)

Abe, Y; Ushirogawa, H; Tomioka, K

1997-10-01

Circadian locomotor rhythm and its underlying mechanism were investigated in the cricket, Gryllodes sigillatus. Adult male crickets showed a nocturnal locomotor rhythm peaking early in the dark phase of a light to dark cycle. This rhythm persisted under constant darkness (DD) with a free-running period averaging 23.1 +/- 0.3 hr. Although constant bright light made most animals arrhythmic, about 40% of the animals showed free-running rhythms with a period longer than 24 hr under constant dim light condition. On transfer to DD, all arrhythmic animals restored the locomotor rhythm. Bilateral optic nerve severance resulted in free-running of the rhythm even under light-dark cycles. The free-running period of the optic nerve severed animals was significantly longer than sham operated crickets in DD, suggesting that the compound eye plays some role in determining the free-running period. Removal of bilateral lamina-medulla portion of the optic lobe abolished the rhythm under DD. These results demonstrate that the photoreceptor for entrainment is the compound eye and the optic lobe is indispensable for persistence of the rhythm. However, 75% and 54% of the optic lobeless animals showed aberrant rhythms with a period very close to 24 hr under light and temperature cycles, respectively, suggesting that there are neural and/or humoral mechanisms for the aberrant rhythms outside of the optic lobe. Since ocelli removal did not affect the photoperiodically induced rhythm, it is likely that the photoreception for the rhythm is performed through an extraretinal photoreceptor.

The Rewarding and Locomotor-Sensitizing Effects of Repeated Cocaine Administration are Distinct and Separable in Mice

Science.gov (United States)

Riday, Thorfinn T.; Kosofsky, Barry E.; Malanga, C.J.

2011-01-01

Repeated psychostimulant exposure progressively increases their potency to stimulate motor activity in rodents. This behavioral or locomotor sensitization is considered a model for some aspects of drug addiction in humans, particularly drug craving during abstinence. However, the role of increased motor behavior in drug reward remains incompletely understood. Intracranial self-stimulation (ICSS) was measured concurrently with locomotor activity to determine if acute intermittent cocaine administration had distinguishable effects on motor behavior and perception of brain stimulation-reward (BSR) in the same mice. Sensitization is associated with changes in neuronal activity and glutamatergic neurotransmission in brain reward circuitry. Expression of AMPA receptor subunits (GluR1 and GluR2) and CRE binding protein (CREB) was measured in the ventral tegmental area (VTA), dorsolateral striatum (STR) and nucleus accumbens (NAc) before and after a sensitizing regimen of cocaine, with and without ICSS. Repeated cocaine administration sensitized mice to its locomotor stimulating effects but not its ability to potentiate BSR. ICSS increased GluR1 in the VTA but not NAc or STR, demonstrating selective changes in protein expression with electrical stimulation of discrete brain structures. Repeated cocaine reduced GluR1, GluR2 and CREB expression in the NAc, and reductions of GluR1 and GluR2 but not CREB were further enhanced by ICSS. These data suggest that the effects of repeated cocaine exposure on reward and motor processes are dissociable in mice, and that reduction of excitatory neurotransmission in the NAc may predict altered motor function independently from changes in reward perception. PMID:22197517

The Interface of IT Capabilities and Disruptive Innovations

DEFF Research Database (Denmark)

Baiyere, Abayomi

2017-01-01

The occurrence of disruptive innovations tends to challenge the fabric, structure and capability that define firms facing their threat. Prior research indicates that the capacity of a firm to restructure and reconfigure its resources to face/leverage such turbulent situations is dependent on how...... well it can orchestrate its capabilities. Although IT capability has been identified as one of the essential capability of today’s organisations, managers as well as researchers are yet to uncover the dynamics through which an organisation’s IT capability can be leveraged in disruptive innovation...... situations. This paper contributes to our understanding in this direction by conceptually exploring the different roles of an organisation's IT capabilitiy in disruptive innovation scenarios. The paper provides a synthesis of the current state of knowledge about both concepts and extends this to highlight...

The glucagon-like peptide 1 analogue Exendin-4 attenuates the nicotine-induced locomotor stimulation, accumbal dopamine release, conditioned place preference as well as the expression of locomotor sensitization in mice.

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Emil Egecioglu

Full Text Available The gastrointestinal peptide glucagon-like peptide 1 (GLP-1 is known to regulate consummatory behavior and is released in response to nutrient ingestion. Analogues of this peptide recently emerged as novel pharmacotherapies for treatment of type II diabetes since they reduce gastric emptying, glucagon secretion as well as enhance glucose-dependent insulin secretion. The findings that GLP-1 targets reward related areas including mesolimbic dopamine areas indicate that the physiological role of GLP-1 extends beyond food intake and glucose homeostasis control to include reward regulation. The present series of experiments was therefore designed to investigate the effects of the GLP-1 receptor agonist, Exendin-4 (Ex4, on established nicotine-induced effects on the mesolimbic dopamine system in mice. Specifically, we show that treatment with Ex4, at a dose with no effect per se, attenuate nicotine-induced locomotor stimulation, accumbal dopamine release as well as the expression of conditioned place preference in mice. In accordance, Ex4 also blocks nicotine-induced expression of locomotor sensitization in mice. Given that development of nicotine addiction largely depends on the effects of nicotine on the mesolimbic dopamine system these findings indicate that the GLP-1 receptor may be a potential target for the development of novel treatment strategies for nicotine cessations in humans.

The morphological development of the locomotor and cardiac muscles of the migratory barnacle goose (Branta leucopsis)

NARCIS (Netherlands)

Bishop, CM; Butler, PJ; ElHaj, AJ; Egginton, S; Loonen, MJJE

The masses of the locomotor and cardiac muscles of wild barnacle goose goslings, from a migratory population, were examined systematically during development and their values compared to those of pre-migratory geese. Pre-flight development was typified by approximately linear increases of body, leg,

The correspondence between proximal phalanx morphology and locomotion: implications for inferring the locomotor behavior of fossil catarrhines.

Science.gov (United States)

Rein, Thomas R

2011-11-01

Phalanges are considered to be highly informative in the reconstruction of extinct primate locomotor behavior since these skeletal elements directly interact with the substrate during locomotion. Variation in shaft curvature and relative phalangeal length has been linked to differences in the degree of suspension and overall arboreal locomotor activities. Building on previous work, this study investigated these two skeletal characters in a comparative context to analyze function, while taking evolutionary relationships into account. This study examined the correspondence between proportions of suspension and overall substrate usage observed in 17 extant taxa and included angle of curvature and relative phalangeal length. Predictive models based on these traits are reported. Published proportions of different locomotor behaviors were regressed against each phalangeal measurement and a size proxy. The relationship between each behavior and skeletal trait was investigated using ordinary least-squares, phylogenetic generalized least-squares (pGLS), and two pGLS transformation methods to determine the model of best-fit. Phalangeal curvature and relative length had significant positive relationships with both suspension and overall arboreal locomotion. Cross-validation analyses demonstrated that relative length and curvature provide accurate predictions of relative suspensory behavior and substrate usage in a range of extant species when used together in predictive models. These regression equations provide a refined method to assess the amount of suspensory and overall arboreal locomotion characterizing species in the catarrhine fossil record. Copyright © 2011 Wiley-Liss, Inc.

Effects of Innovative WALKBOT Robotic-Assisted Locomotor Training on Balance and Gait Recovery in Hemiparetic Stroke: A Prospective, Randomized, Experimenter Blinded Case Control Study With a Four-Week Follow-Up.

Science.gov (United States)

Kim, Soo-Yeon; Yang, Li; Park, In Jae; Kim, Eun Joo; JoshuaPark, Min Su; You, Sung Hyun; Kim, Yun-Hee; Ko, Hyun-Yoon; Shin, Yong-Il

2015-07-01

The present clinical investigation was to ascertain whether the effects of WALKBOT-assisted locomotor training (WLT) on balance, gait, and motor recovery were superior or similar to the conventional locomotor training (CLT) in patients with hemiparetic stroke. Thirty individuals with hemiparetic stroke were randomly assigned to either WLT or CLT. WLT emphasized on a progressive, conventional locomotor retraining practice (40 min) combined with the WALKBOT-assisted, haptic guidance and random variable locomotor training (40 min) whereas CLT involved conventional physical therapy alone (80 min). Both intervention dosages were standardized and provided for 80 min, five days/week for four weeks. Clinical outcomes included function ambulation category (FAC), Berg balance scale (BBS), Korean modified Barthel index (K-MBI), modified Ashworth scale (MAS), and EuroQol-5 dimension (EQ-5D) before and after the four-week program as well as at follow-up four weeks after the intervention. Two-way repeated measure ANOVA showed significant interaction effect (time × group) for FAC (p=0.02), BBS (p=0.03) , and K-MBI (p=0.00) across the pre-training, post-training, and follow-up tests, indicating that WLT was more beneficial for balance, gait and daily activity function than CLT alone. However, no significant difference in other variables was observed. This is the first clinical trial that highlights the superior, augmented effects of the WALKBOT-assisted locomotor training on balance, gait and motor recovery when compared to the conventional locomotor training alone in patients with hemiparetic stroke.

Membrana amniótica preservada em glicerina no reparo de feridas cutâneas de membros locomotores de eqüinos

OpenAIRE

Oliveira,Valdemir Alves de; Alvarenga,José de

1998-01-01

Neste estudo experimental, avaliou-se o uso de membrana amniótica eqüina preservada em glicerina 98%, à temperatura ambiente, em feridas com cura por segunda intenção, nos membros locomotores de eqüinos. Foram provocadas cirurgicamente feridas de 9,6cm² na face lateral da articulação metacarpo-falangeana, face medial do terço proximal do metacarpo e face lateral do terço médio do metatarso de ambos os membros locomotores de cinco eqüinos adultos, perfazendo total de trinta feridas. Foram cons...

Locomotor Training and Strength and Balance Exercises for Walking Recovery After Stroke: Response to Number of Training Sessions.

Science.gov (United States)

Rose, Dorian K; Nadeau, Stephen E; Wu, Samuel S; Tilson, Julie K; Dobkin, Bruce H; Pei, Qinglin; Duncan, Pamela W

2017-11-01

Evidence-based guidelines are needed to inform rehabilitation practice, including the effect of number of exercise training sessions on recovery of walking ability after stroke. The objective of this study was to determine the response to increasing number of training sessions of 2 interventions-locomotor training and strength and balance exercises-on poststroke walking recovery. This is a secondary analysis of the Locomotor Experience Applied Post-Stroke (LEAPS) randomized controlled trial. Six rehabilitation sites in California and Florida and participants' homes were used. Participants were adults who dwelled in the community (N=347), had had a stroke, were able to walk at least 3 m (10 ft) with assistance, and had completed the required number of intervention sessions. Participants received 36 sessions (3 times per week for 12 weeks), 90 minutes in duration, of locomotor training (gait training on a treadmill with body-weight support and overground training) or strength and balance training. Talking speed, as measured by the 10-Meter Walk Test, and 6-minute walking distance were assessed before training and following 12, 24, and 36 intervention sessions. Participants at 2 and 6 months after stroke gained in gait speed and walking endurance after up to 36 sessions of treatment, but the rate of gain diminished steadily and, on average, was very low during the 25- to 36-session epoch, regardless of treatment type or severity of impairment. Results may not generalize to people who are unable to initiate a step at 2 months after stroke or people with severe cardiac disease. In general, people who dwelled in the community showed improvements in gait speed and walking distance with up to 36 sessions of locomotor training or strength and balance exercises at both 2 and 6 months after stroke. However, gains beyond 24 sessions tended to be very modest. The tracking of individual response trajectories is imperative in planning treatment. Published by Oxford University

Oxytocin decreases cocaine taking, cocaine seeking, and locomotor activity in female rats

OpenAIRE

Leong, Kah-Chung; Zhou, Luyi; Ghee, Shannon M.; See, Ronald E.; Reichel, Carmela M.

2016-01-01

Oxytocin has been shown to decrease cocaine taking and seeking in male rats, suggesting potential treatment efficacy for drug addiction. In the present study, we extended these findings to the assessment of cocaine seeking and taking in female rats. Further, we made direct comparisons of oxytocin’s impact on cocaine induced locomotor activity in both males and females. In females, systemic oxytocin (0.3, 1.0, 3.0 mg/kg) attenuated lever pressing for cocaine during self-administration and oxyt...

Studies of evolutionary temperature adaptation: muscle function and locomotor performance in Antarctic fish.

Science.gov (United States)

Franklin, C E

1998-09-01

1. Studies of evolutionary temperature adaptation of muscle and locomotor performance in fish are reviewed with a focus on the Antarctic fauna living at subzero temperatures. 2. Only limited data are available to compare the sustained and burst swimming kinematics and performance of Antarctic, temperate and tropical species. Available data indicate that low temperatures limit maximum swimming performance and this is especially evident in fish larvae. 3. In a recent study, muscle performance in the Antarctic rock cod Notothenia coriiceps at 0 degree C was found to be sufficient to produce maximum velocities during burst swimming that were similar to those seen in the sculpin Myoxocephalus scorpius at 10 degrees C, indicating temperature compensation of muscle and locomotor performance in the Antarctic fish. However, at 15 degrees C, sculpin produce maximum swimming velocities greater than N. coriiceps at 0 degree C. 4. It is recommended that strict hypothesis-driven investigations using ecologically relevant measures of performance are undertaken to study temperature adaptation in Antarctic fish. Recent detailed phylogenetic analyses of the Antarctic fish fauna and their temperate relatives will allow a stronger experimental approach by helping to separate what is due to adaptation to the cold and what is due to phylogeny alone.

Open field locomotor activity and anxiety-related behaviors in mucopolysaccharidosis type IIIA mice.

Science.gov (United States)

Lau, Adeline A; Crawley, Allison C; Hopwood, John J; Hemsley, Kim M

2008-08-05

Mucopolysaccharidosis (MPS) IIIA, or Sanfilippo syndrome, is a lysosomal storage disorder characterized by severe and progressive neuropathology. Following an asymptomatic period, patients may present with sleep disturbances, cognitive decline, aggressive tendencies and hyperactivity. A naturally-occurring mouse model of MPS IIIA also exhibits many of these behavioral features and has been recently back-crossed onto a C57BL/6 genetic background. To more thoroughly characterize the behavioral phenotype of congenic MPS IIIA mice, we assessed exploratory activity and unconditioned anxiety-related behavior in the elevated plus maze (EPM) and open field locomotor activity. Although MPS IIIA male mice were less active in the EPM at 18 and 20 weeks of age, they were more likely to explore the open arms than their normal counter-parts suggesting reduced anxiety. Repeated EPM testing reduced exploration of the open arms in MPS IIIA mice. In the open field test, significant reductions in activity were evident in naïve-tested male MPS IIIA mice from 10 weeks of age. Female normal and MPS IIIA mice displayed similar exploratory activity in the open field test. These differences in anxiety and locomotor activity will allow us to evaluate the efficacy of therapeutic regimes for MPS IIIA as a forerunner to developing safe and effective therapies for Sanfilippo patients.

A framework for offshore vendor capability development

Science.gov (United States)

Yusuf Wibisono, Yogi; Govindaraju, Rajesri; Irianto, Dradjad; Sudirman, Iman

2016-02-01

Offshore outsourcing is a common practice conducted by companies, especially in developed countries, by relocating one or more their business processes to other companies abroad, especially in developing countries. This practice grows rapidly owing to the ease of accessing qualified vendors with a lower cost. Vendors in developing countries compete more intensely to acquire offshore projects. Indonesia is still below India, China, Malaysia as main global offshore destinations. Vendor capability is among other factors that contribute to the inability of Indonesian vendor in competing with other companies in the global market. Therefore, it is essential to study how to increase the vendor's capability in Indonesia, in the context of global offshore outsourcing. Previous studies on the vendor's capability mainly focus on capabilities without considering the dynamic of capabilities due to the environmental changes. In order to be able to compete with competitors and maintain the competitive advantage, it is necessary for vendors to develop their capabilities continuously. The purpose of this study is to develop a framework that describes offshore vendor capability development along the client-vendor relationship stages. The framework consists of three main components, i.e. the stages of client-vendor relationship, the success of each stage, and the capabilities of vendor at each stage.

Limited interlimb transfer of locomotor adaptations to a velocity-dependent force field during unipedal walking.

Science.gov (United States)

Houldin, Adina; Chua, Romeo; Carpenter, Mark G; Lam, Tania

2012-08-01

Several studies have demonstrated that motor adaptations to a novel task environment can be transferred between limbs. Such interlimb transfer of motor commands is consistent with the notion of centrally driven strategies that can be generalized across different frames of reference. So far, studies of interlimb transfer of locomotor adaptations have yielded disparate results. Here we sought to determine whether locomotor adaptations in one (trained) leg show transfer to the other (test) leg during a unipedal walking task. We hypothesized that adaptation in the test leg to a velocity-dependent force field previously experienced by the trained leg will be faster, as revealed by faster recovery of kinematic errors and earlier onset of aftereffects. Twenty able-bodied adults walked unipedally in the Lokomat robotic gait orthosis, which applied velocity-dependent resistance to the legs. The amount of resistance was scaled to 10% of each individual's maximum voluntary contraction of the hip flexors. Electromyography and kinematics of the lower limb were recorded. All subjects were right-leg dominant and were tested for transfer of motor adaptations from the right leg to the left leg. Catch trials, consisting of unexpected removal of resistance, were presented after the first step with resistance and after a period of adaptation to test for aftereffects. We found no significant differences in the sizes of the aftereffects between the two legs, except for peak hip flexion during swing, or in the rate at which peak hip flexion adapted during steps against resistance between the two legs. Our results indicate that interlimb transfer of these types of locomotor adaptation is not a robust phenomenon. These findings add to our current understanding of motor adaptations and provide further evidence that generalization of adaptations may be dependent on the movement task.

Design Management Capability and Product Innovation in SMEs

OpenAIRE

Fernández-Mesa, Ana Isabel; ALEGRE VIDAL, JOAQUIN; CHIVA GOMEZ, RICARDO; Gutiérrez Gracia, Antonio

2013-01-01

[EN] Purpose The aim of this paper is to present design management as a dynamic capability and to analyze its mediating role between organizational learning capability and product innovation performance in small and medium enterprises (SMEs). Design/methodology/approach Structural equation modeling is used to test the research hypotheses based on data from the Italian and Spanish ceramic tile industries. The data are derived from the responses of 182 companies (50 percent of the targ...

Locomotor inhibition in adults horses faced to stressors: a single postpartum experience may be enough!

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Virginie eDurier

2012-10-01

Full Text Available Despite the number of postpartum handling that a newborn experiences, few studies focus on their long-term consequences. In rats, regular long separations from the mother, during the early life, led to modifications of the locomotor activity when the animal is confronted to a stressor. In horses, one component of the behavioural response to stressful situation is active locomotion. We wondered if the routine postpartum handling undergone by foals, would affect their level of reactivity or the way they express their stress, when older. One single prolonged bout of handling just after birth clearly affected later adult expression of stress reactivity. In social separation associated with novelty, handled and unhandled horses produced an equal amount of whinnies, showing a similar vocal response to stress. However, both groups differed in their locomotor response to the situations. Early-handled foals expressed less of the active forms of locomotion than the control group. Our findings highlight the need of further reflections on long-term effects of routine handlings procedures close to birth.

Differences in Monoamine Oxidase Activity in the Brain of Wistar and August Rats with High and Low Locomotor Activity: A Cytochemical Study.

Science.gov (United States)

Sergutina, A V; Rakhmanova, V I

2016-06-01

Monoamine oxidase activity was quantitatively assessed by cytochemical method in brain structures (layers III and V of the sensorimotor cortex, caudate nucleus, nucleus accumbens, hippocampal CA3 field) of rats of August line and Wistar population with high and low locomotor activity in the open fi eld test. Monoamine oxidase activity (substrate tryptamine) predominated in the nucleus accumbens of Wistar rats with high motor activity in comparison with rats with low locomotor activity. In August rats, enzyme activity (substrates tryptamine and serotonin) predominated in the hippocampus of animals with high motor activity. Comparison of August rats with low locomotor activity and Wistar rats with high motor activity (i.e. animals demonstrating maximum differences in motor function) revealed significantly higher activity of the enzyme (substrates tryptamine and serotonin) in the hippocampus of Wistar rats. The study demonstrates clear-cut morphochemical specificity of monoaminergic metabolism based on the differences in the cytochemical parameter "monoamine oxidase activity", in the studied brain structures, responsible for the formation and realization of goal-directed behavior in Wistar and August rats.

Qualification of spontaneous undirected locomotor behavior of fish for sublethal toxicity testing. Part 2. Variability of measurement parameters under toxicant-induced stress

Energy Technology Data Exchange (ETDEWEB)

Grillitsch, B.; Vogl, C.; Wytek, R.

1999-12-01

Spontaneous locomotor behavior of semiadult zebra fish (Brachydanio rerio) was recorded under sublethal short-term exposure to the anionic technical surfactant, linear alkylbenzene sulfonate (C{sub 10-13}-LAS) and cadmium in single compound tests using an automated video-monitoring and object-tracing system. Vertical position and swimming velocity in the horizontal and vertical directions were used as behavioral measurement parameters. Data were analyzed by different statistical methods. In pairwise comparisons, consistent, statistically significant, and toxicant-induced alterations of locomotor behavior were observed only for test concentrations, which also caused aspectoric symptoms of intoxication. This comparatively low sensitivity of the behavioral indication criteria was related to high variation in the measurement parameters and corresponding high, minimum detectable, statistically significant, and toxicant-induced deviations. In contrast, results obtained by regression analysis showed significant trends in locomotor activity over the range of toxicant concentrations tested. Thus, the findings support the inappropriateness of no observed effect concentrations and the lowest observed effect concentrations as summary measures of toxicity and indicate that the regression analysis approach is superior to the analysis of variance approach.

Effect of ambient temperature on the thermoregulatory and locomotor stimulant effects of 4-methylmethcathinone in Wistar and Sprague-Dawley rats.

Directory of Open Access Journals (Sweden)

M Jerry Wright

Full Text Available The drug 4-methylmethcathinone (4-MMC; aka, mephedrone, MMCAT, "plant food", "bath salts" is a recent addition to the list of popular recreational psychomotor-stimulant compounds. Relatively little information about this drug is available in the scientific literature, but popular media reports have driven recent drug control actions in the UK and several US States. Online user reports of subjective similarity to 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy" prompted the current investigation of the thermoregulatory and locomotor effects of 4-MMC. Male Wistar and Sprague-Dawley rats were monitored after subcutaneous administration of 4-MMC (1-10 mg/kg using an implantable radiotelemetry system under conditions of low (23°C and high (27°C ambient temperature. A reliable reduction of body temperature was produced by 4-MMC in Wistar rats at 23°C or 27°C with only minimal effect in Sprague-Dawley rats. Increased locomotor activity was observed after 4-MMC administration in both strains with significantly more activity produced in the Sprague-Dawley strain. The 10 mg/kg s.c. dose evoked greater increase in extracellular serotonin, compared with dopamine, in the nucleus accumbens. Follow-up studies confirmed that the degree of locomotor stimulation produced by 10 mg/kg 4-MMC was nearly identical to that produced by 1 mg/kg d-methamphetamine in each strain. Furthermore, hypothermia produced by the serotonin 1(A/7 receptor agonist 8-hydroxy-N,N-dipropyl-2-aminotetralin (8-OH-DPAT was similar in each strain. These results show that the cathinone analog 4-MMC exhibits thermoregulatory and locomotor properties that are distinct from those established for methamphetamine or MDMA in prior work, despite recent evidence of neuropharmacological similarity with MDMA.

Locomotor-like leg movements evoked by rhythmic arm movements in humans.

Directory of Open Access Journals (Sweden)

Francesca Sylos-Labini

Full Text Available Motion of the upper limbs is often coupled to that of the lower limbs in human bipedal locomotion. It is unclear, however, whether the functional coupling between upper and lower limbs is bi-directional, i.e. whether arm movements can affect the lumbosacral locomotor circuitry. Here we tested the effects of voluntary rhythmic arm movements on the lower limbs. Participants lay horizontally on their side with each leg suspended in an unloading exoskeleton. They moved their arms on an overhead treadmill as if they walked on their hands. Hand-walking in the antero-posterior direction resulted in significant locomotor-like movements of the legs in 58% of the participants. We further investigated quantitatively the responses in a subset of the responsive subjects. We found that the electromyographic (EMG activity of proximal leg muscles was modulated over each cycle with a timing similar to that of normal locomotion. The frequency of kinematic and EMG oscillations in the legs typically differed from that of arm oscillations. The effect of hand-walking was direction specific since medio-lateral arm movements did not evoke appreciably leg air-stepping. Using externally imposed trunk movements and biomechanical modelling, we ruled out that the leg movements associated with hand-walking were mainly due to the mechanical transmission of trunk oscillations. EMG activity in hamstring muscles associated with hand-walking often continued when the leg movements were transiently blocked by the experimenter or following the termination of arm movements. The present results reinforce the idea that there exists a functional neural coupling between arm and legs.

The relationship between hippocampal EEG theta activity and locomotor behaviour in freely moving rats: effects of vigabatrin.

Science.gov (United States)

Bouwman, B M; van Lier, H; Nitert, H E J; Drinkenburg, W H I M; Coenen, A M L; van Rijn, C M

2005-01-30

The relationship between hippocampal electroencephalogram (EEG) theta activity and locomotor speed in both spontaneous and forced walking conditions was studied in rats after vigabatrin injection (500 mg/kg i.p.). Vigabatrin increased the percentage of time that rats spent being immobile. During spontaneous walking in the open field, the speed of locomotion was increased by vigabatrin, while theta peak frequency was decreased. Vigabatrin also reduced the theta peak frequency during forced (speed controlled) walking. There was only a weak positive correlation (r=0.22) between theta peak frequency and locomotor speed for the saline condition. Furthermore, vigabatrin abolishes the weak relationship between speed of locomotion and theta peak frequency. Vigabatrin and saline did not differ in the slope of the regression line, but showed different offset points at the theta peak frequency axis. Thus, other factors than speed of locomotion seem to be involved in determination of the theta peak frequency.

Neonatal programming with testosterone propionate reduces dopamine transporter expression in nucleus accumbens and methylphenidate-induced locomotor activity in adult female rats.

Science.gov (United States)

Dib, Tatiana; Martínez-Pinto, Jonathan; Reyes-Parada, Miguel; Torres, Gonzalo E; Sotomayor-Zárate, Ramón

2018-07-02

Research in programming is focused on the study of stimuli that alters sensitive periods in development, such as prenatal and neonatal stages, that can produce long-term deleterious effects. These effects can occur in various organs or tissues such as the brain, affecting brain circuits and related behaviors. Our laboratory has demonstrated that neonatal programming with sex hormones affects the mesocorticolimbic circuitry, increasing the synthesis and release of dopamine (DA) in striatum and nucleus accumbens (NAcc). However, the behavioral response to psychostimulant drugs such as methylphenidate and the possible mechanism(s) involved have not been studied in adult rats exposed to sex hormones during the first hours of life. Thus, the aim of this study was to examine the locomotor activity induced by methylphenidate (5mg/kg i.p.) and the expression of the DA transporter (DAT) in NAcc of adult rats exposed to a single dose of testosterone propionate (TP: 1mg/50μLs.c.) or estradiol valerate (EV: 0.1mg/50μLs.c.) at postnatal day 1. Our results demonstrated that adult female rats treated with TP have a lower methylphenidate-induced locomotor activity compared to control and EV-treated adult female rats. This reduction in locomotor activity is related with a lower NAcc DAT expression. However, neither methylphenidate-induced locomotor activity nor NAcc DAT expression was affected in EV or TP-treated adult male rats. Our results suggest that early exposure to sex hormones affects long-term dopaminergic brain areas involved in the response to psychostimulants, which could be a vulnerability factor to favor the escalating doses of drugs of abuse. Copyright © 2017 Elsevier B.V. All rights reserved.

Are Hydrostatic Models Still Capable of Simulating Oceanic Fronts

Science.gov (United States)

2016-11-10

Hydrostatic Models Still Capable of Simulating Oceanic Fronts Yalin Fan Zhitao Yu Ocean Dynamics and Prediction Branch Oceanography Division FengYan Shi...OF PAGES 17. LIMITATION OF ABSTRACT Are Hydrostatic Models Still Capable of Simulating Oceanic Fronts? Yalin Fan, Zhitao Yu, and, Fengyan Shi1 Naval...mixed layer and thermocline simulations as well as large scale circulations. Numerical experiments are conducted using hydrostatic (HY) and

Effects of ketamine on the unconditioned and conditioned locomotor activity of preadolescent and adolescent rats: impact of age, sex, and drug dose.

Science.gov (United States)

McDougall, Sanders A; Moran, Andrea E; Baum, Timothy J; Apodaca, Matthew G; Real, Vanessa

2017-09-01

Ketamine is used by preadolescent and adolescent humans for licit and illicit purposes. The goal of the present study was to determine the effects of acute and repeated ketamine treatment on the unconditioned behaviors and conditioned locomotor activity of preadolescent and adolescent rats. To assess unconditioned behaviors, female and male rats were injected with ketamine (5-40 mg/kg), and distance traveled was measured on postnatal day (PD) 21-25 or PD 41-45. To assess conditioned activity, male and female rats were injected with saline or ketamine in either a novel test chamber or the home cage on PD 21-24 or PD 41-44. One day later, rats were injected with saline and conditioned activity was assessed. Ketamine produced a dose-dependent increase in the locomotor activity of preadolescent and adolescent rats. Preadolescent rats did not exhibit sex differences, but ketamine-induced locomotor activity was substantially stronger in adolescent females than males. Repeated ketamine treatment neither caused a day-dependent increase in locomotor activity nor produced conditioned activity in preadolescent or adolescent rats. The activity-enhancing effects of ketamine are consistent with the actions of an indirect dopamine agonist, while the inability of ketamine to induce conditioned activity is unlike what is observed after repeated cocaine or amphetamine treatment. This dichotomy could be due to ketamine's ability to both enhance DA neurotransmission and antagonize N-methyl-D-aspartate (NMDA) receptors. Additional research will be necessary to parse out the relative contributions of DA and NMDA system functioning when assessing the behavioral effects of ketamine during early ontogeny.

Impact of Organizational Inertia and Dynamic Capabilities on Educational Performance of the Charitable Societies and Its Impact on Mathematical Performance of Elementary At-Risk Students

Science.gov (United States)

Amiripour, Parvaneh; Dossey, John A.; Shahvarani, Ahmad

2017-01-01

This study is an adjunct to a research effort focused on a mathematical curricular innovation in four non-governmental schools in Tehran, Iran. This study queried balanced, random sample of 100 educational personnel from the schools concerning dynamic capabilities associated with change (sensing opportunities, seizing opportunities, and…

Functional Independence and Quality of Life for Persons with Locomotor Disabilities in Institutional Based Rehabilitation and Community Based Rehabilitation - A Comparative Study

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A Amarnath

2012-12-01

Full Text Available Purpose: To compare the functional independence and quality of life of persons with locomotor disabilities who undergo Institutional Based Rehabilitation (IBR and similar persons who undergo Community Based Rehabilitation (CBR. Methods: Purposive sampling was done. Thirty males with locomotor disabilities -15 from IBR and 15 from CBR- were selected. Both the groups were first administered the Functional Independence Measure (FIM questionnaire, followed by the Quality of Life (WHOQOL-BREF questionnaire.Results: There were no significant differencse between IBR and CBR with regard to functional independence  (t value = -1.810, P doi: 10.5463/dcid.v23i3.147

A Drosophila systems model of pentylenetetrazole induced locomotor plasticity responsive to antiepileptic drugs

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Singh Priyanka

2009-01-01

Full Text Available Abstract Background Rodent kindling induced by PTZ is a widely used model of epileptogenesis and AED testing. Overlapping pathophysiological mechanisms may underlie epileptogenesis and other neuropsychiatric conditions. Besides epilepsy, AEDs are widely used in treating various neuropsychiatric disorders. Mechanisms of AEDs' long term action in these disorders are poorly understood. We describe here a Drosophila systems model of PTZ induced locomotor plasticity that is responsive to AEDs. Results We empirically determined a regime in which seven days of PTZ treatment and seven days of subsequent PTZ discontinuation respectively cause a decrease and an increase in climbing speed of Drosophila adults. Concomitant treatment with NaVP and LEV, not ETH, GBP and VGB, suppressed the development of locomotor deficit at the end of chronic PTZ phase. Concomitant LEV also ameliorated locomotor alteration that develops after PTZ withdrawal. Time series of microarray expression profiles of heads of flies treated with PTZ for 12 hrs (beginning phase, two days (latent phase and seven days (behaviorally expressive phase showed only down-, not up-, regulation of genes; expression of 23, 2439 and 265 genes were downregulated, in that order. GO biological process enrichment analysis showed downregulation of transcription, neuron morphogenesis during differentiation, synaptic transmission, regulation of neurotransmitter levels, neurogenesis, axonogenesis, protein modification, axon guidance, actin filament organization etc. in the latent phase and of glutamate metabolism, cell communication etc. in the expressive phase. Proteomic interactome based analysis provided further directionality to these events. Pathway overrepresentation analysis showed enrichment of Wnt signaling and other associated pathways in genes downregulated by PTZ. Mining of available transcriptomic and proteomic data pertaining to established rodent models of epilepsy and human epileptic

Development Of A Dynamic Radiographic Capability Using High-Speed Video

Science.gov (United States)

Bryant, Lawrence E.

1985-02-01

High-speed video equipment can be used to optically image up to 2,000 full frames per second or 12,000 partial frames per second. X-ray image intensifiers have historically been used to image radiographic images at 30 frames per second. By combining these two types of equipment, it is possible to perform dynamic x-ray imaging of up to 2,000 full frames per second. The technique has been demonstrated using conventional, industrial x-ray sources such as 150 Kv and 300 Kv constant potential x-ray generators, 2.5 MeV Van de Graaffs, and linear accelerators. A crude form of this high-speed radiographic imaging has been shown to be possible with a cobalt 60 source. Use of a maximum aperture lens makes best use of the available light output from the image intensifier. The x-ray image intensifier input and output fluors decay rapidly enough to allow the high frame rate imaging. Data are presented on the maximum possible video frame rates versus x-ray penetration of various thicknesses of aluminum and steel. Photographs illustrate typical radiographic setups using the high speed imaging method. Video recordings show several demonstrations of this technique with the played-back x-ray images slowed down up to 100 times as compared to the actual event speed. Typical applications include boiling type action of liquids in metal containers, compressor operation with visualization of crankshaft, connecting rod and piston movement and thermal battery operation. An interesting aspect of this technique combines both the optical and x-ray capabilities to observe an object or event with both external and internal details with one camera in a visual mode and the other camera in an x-ray mode. This allows both kinds of video images to appear side by side in a synchronized presentation.

Development of a dynamic radiographic capability using high-speed video

International Nuclear Information System (INIS)

Bryant, L.E. Jr.

1984-01-01

High-speed video equipment can be used to optically image up to 2000 full frames per second or 12,000 partial frames per second. X-ray image intensifiers have historically been used to image radiographic images at 30 frames per second. By combining these two types of equipment, it is possible to perform dynamic x-ray imaging of up to 2,000 full frames per second. The technique has been demonstrated using conventional, industrial x-ray sources such as 150 kV and 300 kV constant potential x-ray generators, 2.5 MeV Van de Graaffs, and linear accelerators. A crude form of this high-speed radiographic imaging has been shown to be possible with a cobalt 60 source. Use of a maximum aperture lens makes best use of the available light output from the image intensifier. The x-ray image intensifier input and output fluors decay rapidly enough to allow the high frame rate imaging. Data are presented on the maximum possible video frame rates versus x-ray penetration of various thicknesses of aluminum and steel. Photographs illustrate typical radiographic setups using the high speed imaging method. Video recordings show several demonstrations of this technique with the played-back x-ray images slowed down up to 100 times as compared to the actual event speed. Typical applications include boiling type action of liquids in metal containers, compressor operation with visualization of crankshaft, connecting rod and piston movement and thermal battery operation. An interesting aspect of this technique combines both the optical and x-ray capabilities to observe an object or event with both external and internal details with one camera in a visual mode and the other camera in an x-ray mode. This allows both kinds of video images to appear side by side in a synchronized presentation

Spinal cord injury: overview of experimental approaches used to restore locomotor activity.

Science.gov (United States)

Fakhoury, Marc

2015-01-01

Spinal cord injury affects more than 2.5 million people worldwide and can lead to paraplegia and quadriplegia. Anatomical discontinuity in the spinal cord results in disruption of the impulse conduction that causes temporary or permanent changes in the cord's normal functions. Although axonal regeneration is limited, damage to the spinal cord is often accompanied by spontaneous plasticity and axon regeneration that help improve sensory and motor skills. The recovery process depends mainly on synaptic plasticity in the preexisting circuits and on the formation of new pathways through collateral sprouting into neighboring denervated territories. However, spontaneous recovery after spinal cord injury can go on for several years, and the degree of recovery is very limited. Therefore, the development of new approaches that could accelerate the gain of motor function is of high priority to patients with damaged spinal cord. Although there are no fully restorative treatments for spinal injury, various rehabilitative approaches have been tested in animal models and have reached clinical trials. In this paper, a closer look will be given at the potential therapies that could facilitate axonal regeneration and improve locomotor recovery after injury to the spinal cord. This article highlights the application of several interventions including locomotor training, molecular and cellular treatments, and spinal cord stimulation in the field of rehabilitation research. Studies investigating therapeutic approaches in both animal models and individuals with injured spinal cords will be presented.

Proprioceptive input resets central locomotor rhythm in the spinal cat

DEFF Research Database (Denmark)

Conway, B. A.; Hultborn, H.; Kiehn, O.

1987-01-01

The reflex regulation of stepping is an important factor in adapting the step cycle to changes in the environment. The present experiments have examined the influence of muscle proprioceptors on centrally generated rhythmic locomotor activity in decerebrate unanesthetized cats with a spinal...... fictive locomotion in a coordinated fashion. An extensor group I volley delivered during a flexor burst would abruptly terminate the flexor activity and initiate an extensor burst. The same stimulus given during an extensor burst prolonged the extensor activity while delaying the appearance...... afferents. Thus an increased load of limb extensors during the stance phase would enhance and prolong extensor activity while simultaneously delaying the transition to the swing phase of the step cycle....

Distribution of networks generating and coordinating locomotor activity in the neonatal rat spinal cord in vitro: a lesion study

DEFF Research Database (Denmark)

Kjaerulff, O; Kiehn, O

1996-01-01

The isolated spinal cord of the newborn rat contains networks that are able to create a patterned motor output resembling normal locomotor movements. In this study, we sought to localize the regions of primary importance for rhythm and pattern generation using specific mechanical lesions. We used...... ventral root recordings to monitor neuronal activity and tested the ability of various isolated parts of the caudal thoraciclumbar cord to generate rhythmic bursting in a combination of 5-HT and NMDA. In addition, pathways mediating left/right and rostrocaudal burst alternation were localized. We found......, these pathways were distributed along the lumbar enlargement. Both lateral and ventral funiculi were sufficient to coordinate activity in the rostral and caudal regions. We conclude that the networks organizing locomotor-related activity in the spinal cord of the newborn rat are distributed....

Improving the forming capability of laser dynamic forming by using rubber as a forming medium

Science.gov (United States)

Shen, Zongbao; Liu, Huixia; Wang, Xiao; Wang, Cuntang

2016-04-01

Laser dynamic forming (LDF) is a novel high velocity forming technique, which employs laser-generated shock wave to load the sample. The forming velocity induced by the high energy laser pulse may exceed the critical forming velocity, resulting in the occurrence of premature fracture. To avoid the above premature fracture, rubber is introduced in LDF as a forming medium to prolong the loading duration in this paper. Laser induced shock wave energy is transferred to the sample in different forming stages, so the forming velocity can be kept below the critical forming velocity when the initial laser energy is high for fracture. Bulge forming experiments with and without rubber were performed to study the effect of rubber on loading duration. The experimental results show that, the shock wave energy attenuates during the propagation through the rubber layer, the rubber can avoid the premature fracture. So the plastic deformation can continue, the forming capability of LDF is improved. Due to the severe plastic deformation under rubber compression, adiabatic shear bands (ASB) occur in LDF with rubber. The material softening in ASB leads to the irregular fracture, which is different from the premature fracture pattern (regular fracture) in LDF without rubber. To better understand this deformation behavior, Johnson-Cook model is used to simulate the dynamic response and the evolution of ASB of copper sample. The simulation results also indicate the rubber can prolong the loading duration.

Trace Amine-Associated Receptor 1 Modulates the Locomotor and Sensitization Effects of Nicotine

Science.gov (United States)

Sukhanov, Ilya; Dorofeikova, Mariia; Dolgorukova, Antonina; Dorotenko, Artem; Gainetdinov, Raul R.

2018-01-01

Trace amine-associated receptor 1 (TAAR1) has emerged as a promising target for addiction treatments because it affects dopamine transmission in the mesolimbic pathway. TAAR1 is involved in the effects of addictive drugs, such as amphetamines, cocaine and ethanol, but the impact of TAAR1 on the effects of nicotine, the psychoactive drug responsible for the development and maintenance of tobacco smoking, has not yet been studied. This study was performed to investigate the possible modulatory action of TAAR1 on the effects of nicotine on locomotor behaviors in rats and mice. Pretreatment with the TAAR1 agonist RO5263397 dose-dependently decreased nicotine-induced hyperlocomotion in rats habituated to locomotor boxes, prevented the development of nicotine sensitization and blocked hypermotility in nicotine-sensitized rats at the highest tested dose (10 mg/kg). The lack of TAAR1 failed to affect the effects of nicotine on the locomotion of mutant mice. Based on the results of the present study, TAAR1 activation attenuates the locomotion-stimulating effects of nicotine on rats. These results further support the previously proposed hypothesis that TAAR1 is a promising target for the prevention and treatment of drug addiction. Further studies aimed at analyzing the effects of TAAR1 agonists on animal models of nicotine addiction are warranted. PMID:29681856

Trace Amine-Associated Receptor 1 Modulates the Locomotor and Sensitization Effects of Nicotine

Directory of Open Access Journals (Sweden)

Ilya Sukhanov

2018-04-01

Full Text Available Trace amine-associated receptor 1 (TAAR1 has emerged as a promising target for addiction treatments because it affects dopamine transmission in the mesolimbic pathway. TAAR1 is involved in the effects of addictive drugs, such as amphetamines, cocaine and ethanol, but the impact of TAAR1 on the effects of nicotine, the psychoactive drug responsible for the development and maintenance of tobacco smoking, has not yet been studied. This study was performed to investigate the possible modulatory action of TAAR1 on the effects of nicotine on locomotor behaviors in rats and mice. Pretreatment with the TAAR1 agonist RO5263397 dose-dependently decreased nicotine-induced hyperlocomotion in rats habituated to locomotor boxes, prevented the development of nicotine sensitization and blocked hypermotility in nicotine-sensitized rats at the highest tested dose (10 mg/kg. The lack of TAAR1 failed to affect the effects of nicotine on the locomotion of mutant mice. Based on the results of the present study, TAAR1 activation attenuates the locomotion-stimulating effects of nicotine on rats. These results further support the previously proposed hypothesis that TAAR1 is a promising target for the prevention and treatment of drug addiction. Further studies aimed at analyzing the effects of TAAR1 agonists on animal models of nicotine addiction are warranted.

Locomotor Stability in a Model Swimmer: Coupling Fluid Dynamics, Neurophysiology and Muscle Mechanics

Science.gov (United States)

2017-07-05

SECURITY CLASSIFICATION OF: We use multiscale modeling and computational fluid dynamics to examine the stability of a swimming organism in the face of...information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and

Developmental Deltamethrin Exposure Causes Persistent Changes in Dopaminergic Gene Expression, Neurochemistry, and Locomotor Activity in Zebrafish.

Science.gov (United States)

Kung, Tiffany S; Richardson, Jason R; Cooper, Keith R; White, Lori A

2015-08-01

Pyrethroids are commonly used insecticides that are considered to pose little risk to human health. However, there is an increasing concern that children are more susceptible to the adverse effects of pesticides. We used the zebrafish model to test the hypothesis that developmental exposure to low doses of the pyrethroid deltamethrin results in persistent alterations in dopaminergic gene expression, neurochemistry, and locomotor activity. Zebrafish embryos were treated with deltamethrin (0.25-0.50 μg/l), at concentrations below the LOAEL, during the embryonic period [3-72 h postfertilization (hpf)], after which transferred to fresh water until the larval stage (2-weeks postfertilization). Deltamethrin exposure resulted in decreased transcript levels of the D1 dopamine (DA) receptor (drd1) and increased levels of tyrosine hydroxylase at 72 hpf. The reduction in drd1 transcripts persisted to the larval stage and was associated with decreased D2 dopamine receptor transcripts. Larval fish, exposed developmentally to deltamethrin, had increased levels of homovanillic acid, a DA metabolite. Since the DA system is involved in locomotor activity, we measured the swim activity of larval fish following a transition to darkness. Developmental exposure to deltamethrin significantly increased larval swim activity which was attenuated by concomitant knockdown of the DA transporter. Acute exposure to methylphenidate, a DA transporter inhibitor, increased swim activity in control larva, while reducing swim activity in larva developmentally exposed to deltamethrin. Developmental exposure to deltamethrin causes locomotor deficits in larval zebrafish, which is likely mediated by dopaminergic dysfunction. This highlights the need to understand the persistent effects of low-dose neurotoxicant exposure during development. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Stakeholder Alignment and Changing Geospatial Information Capabilities

Science.gov (United States)

Winter, S.; Cutcher-Gershenfeld, J.; King, J. L.

2015-12-01

Changing geospatial information capabilities can have major economic and social effects on activities such as drought monitoring, weather forecasts, agricultural productivity projections, water and air quality assessments, the effects of forestry practices and so on. Whose interests are served by such changes? Two common mistakes are assuming stability in the community of stakeholders and consistency in stakeholder behavior. Stakeholder communities can reconfigure dramatically as some leave the discussion, others enter, and circumstances shift — all resulting in dynamic points of alignment and misalignment . New stakeholders can bring new interests, and existing stakeholders can change their positions. Stakeholders and their interests need to be be considered as geospatial information capabilities change, but this is easier said than done. New ways of thinking about stakeholder alignment in light of changes in capability are presented.

Continuous exposure to a novel stressor based on water aversion induces abnormal circadian locomotor rhythms and sleep-wake cycles in mice.

Directory of Open Access Journals (Sweden)

Koyomi Miyazaki

Full Text Available Psychological stressors prominently affect diurnal rhythms, including locomotor activity, sleep, blood pressure, and body temperature, in humans. Here, we found that a novel continuous stress imposed by the perpetual avoidance of water on a wheel (PAWW affected several physiological diurnal rhythms in mice. One week of PAWW stress decayed robust circadian locomotor rhythmicity, while locomotor activity was evident even during the light period when the mice are normally asleep. Daytime activity was significantly upregulated, whereas nighttime activity was downregulated, resulting in a low amplitude of activity. Total daily activity gradually decreased with increasing exposure to PAWW stress. The mice could be exposed to PAWW stress for over 3 weeks without adaptation. Furthermore, continuous PAWW stress enhanced food intake, but decreased body weight and plasma leptin levels, indicating that sleep loss and PAWW stress altered the energy balance in these mice. The diurnal rhythm of corticosterone levels was not severely affected. The body temperature rhythm was diurnal in the stressed mice, but significantly dysregulated during the dark period. Plasma catecholamines were elevated in the stressed mice. Continuous PAWW stress reduced the duration of daytime sleep, especially during the first half of the light period, and increased nighttime sleepiness. Continuous PAWW stress also simultaneously obscured sleep/wake and locomotor activity rhythms compared with control mice. These sleep architecture phenotypes under stress are similar to those of patients with insomnia. The stressed mice could be entrained to the light/dark cycle, and when they were transferred to constant darkness, they exhibited a free-running circadian rhythm with a timing of activity onset predicted by the phase of their entrained rhythms. Circadian gene expression in the liver and muscle was unaltered, indicating that the peripheral clocks in these tissues remained intact.

Neuronal activity in the isolated mouse spinal cord during spontaneous deletions in fictive locomotion: insights into locomotor central pattern generator organization

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Zhong, Guisheng; Shevtsova, Natalia A; Rybak, Ilya A; Harris-Warrick, Ronald M

2012-01-01

We explored the organization of the spinal central pattern generator (CPG) for locomotion by analysing the activity of spinal interneurons and motoneurons during spontaneous deletions occurring during fictive locomotion in the isolated neonatal mouse spinal cord, following earlier work on locomotor deletions in the cat. In the isolated mouse spinal cord, most spontaneous deletions were non-resetting, with rhythmic activity resuming after an integer number of cycles. Flexor and extensor deletions showed marked asymmetry: flexor deletions were accompanied by sustained ipsilateral extensor activity, whereas rhythmic flexor bursting was not perturbed during extensor deletions. Rhythmic activity on one side of the cord was not perturbed during non-resetting spontaneous deletions on the other side, and these deletions could occur with no input from the other side of the cord. These results suggest that the locomotor CPG has a two-level organization with rhythm-generating (RG) and pattern-forming (PF) networks, in which only the flexor RG network is intrinsically rhythmic. To further explore the neuronal organization of the CPG, we monitored activity of motoneurons and selected identified interneurons during spontaneous non-resetting deletions. Motoneurons lost rhythmic synaptic drive during ipsilateral deletions. Flexor-related commissural interneurons continued to fire rhythmically during non-resetting ipsilateral flexor deletions. Deletion analysis revealed two classes of rhythmic V2a interneurons. Type I V2a interneurons retained rhythmic synaptic drive and firing during ipsilateral motor deletions, while type II V2a interneurons lost rhythmic synaptic input and fell silent during deletions. This suggests that the type I neurons are components of the RG, whereas the type II neurons are components of the PF network. We propose a computational model of the spinal locomotor CPG that reproduces our experimental results. The results may provide novel insights into the

Acetylcholinesterase inhibition and locomotor function after motor-sensory cortex impact injury.

Science.gov (United States)

Holschneider, Daniel P; Guo, Yumei; Roch, Margareth; Norman, Keith M; Scremin, Oscar U

2011-09-01

Traumatic brain injury (TBI) induces transient or persistent dysfunction of gait and balance. Enhancement of cholinergic transmission has been reported to accelerate recovery of cognitive function after TBI, but the effects of this intervention on locomotor activity remain largely unexplored. The hypothesis that enhancement of cholinergic function by inhibition of acetylcholinesterase (AChE) improves locomotion following TBI was tested in Sprague-Dawley male rats after a unilateral controlled cortical impact (CCI) injury of the motor-sensory cortex. Locomotion was tested by time to fall on the constant speed and accelerating Rotarod, placement errors and time to cross while walking through a horizontal ladder, activity monitoring in the home cages, and rearing behavior. Assessments were performed the 1st and 2nd day and the 1st, 2nd, and 3rd week after TBI. The AChE inhibitor physostigmine hemisulfate (PHY) was administered continuously via osmotic minipumps implanted subcutaneously at the rates of 1.6-12.8 μmol/kg/day. All measures of locomotion were impaired by TBI and recovered to initial levels between 1 and 3 weeks post-TBI, with the exception of the maximum speed achievable on the accelerating Rotarod, as well as rearing in the open field. PHY improved performance in the accelerating Rotarod at 1.6 and 3.2 μmol/kg/day (AChE activity 95 and 78% of control, respectively), however, higher doses induced progressive deterioration. No effect or worsening of outcomes was observed at all PHY doses for home cage activity, rearing, and horizontal ladder walking. Potential benefits of cholinesterase inhibition on locomotor function have to be weighed against the evidence of the narrow range of useful doses.

Cosmopolitan capabilities in the HE classroom

Directory of Open Access Journals (Sweden)

Veronica Crosbie

2014-04-01

Full Text Available This study, concerning the development of cosmopolitan citizenship, draws on theories of human development and capabilities (Sen 1999; Nussbaum 2000 from a social justice perspective, where individual wellbeing is articulated as having the freedom to live a life of one’s choosing. In the context of an English to Speakers of Other Languages (ESOL classroom this involves paying attention to pedagogical strategies, power dynamics and curriculum content as a means of developing valued beings and doings (or capabilities and functionings as they are described in the literature. Sample activities are presented and evaluated to see to what extent they achieve the desired end. These include critical pedagogical interventions, students’ artefacts and extracts from focus group interviews, class reports and reflective journals.  Results from the textual data offer research evidence of successful curriculum change, demonstrating that the learning that takes place there can make a difference: in terms of the learners’ identity development, capability enhancement and cosmopolitan citizenship.

Development of an Aeroelastic Modeling Capability for Transient Nozzle Side Load Analysis

Science.gov (United States)

Wang, Ten-See; Zhao, Xiang; Zhang, Sijun; Chen, Yen-Sen

2013-01-01

Lateral nozzle forces are known to cause severe structural damage to any new rocket engine in development during test. While three-dimensional, transient, turbulent, chemically reacting computational fluid dynamics methodology has been demonstrated to capture major side load physics with rigid nozzles, hot-fire tests often show nozzle structure deformation during major side load events, leading to structural damages if structural strengthening measures were not taken. The modeling picture is incomplete without the capability to address the two-way responses between the structure and fluid. The objective of this study is to develop a coupled aeroelastic modeling capability by implementing the necessary structural dynamics component into an anchored computational fluid dynamics methodology. The computational fluid dynamics component is based on an unstructured-grid, pressure-based computational fluid dynamics formulation, while the computational structural dynamics component is developed in the framework of modal analysis. Transient aeroelastic nozzle startup analyses of the Block I Space Shuttle Main Engine at sea level were performed. The computed results from the aeroelastic nozzle modeling are presented.

What Is Being Trained? How Divergent Forms of Plasticity Compete To Shape Locomotor Recovery after Spinal Cord Injury.

Science.gov (United States)

Huie, J Russell; Morioka, Kazuhito; Haefeli, Jenny; Ferguson, Adam R

2017-05-15

Spinal cord injury (SCI) is a devastating syndrome that produces dysfunction in motor and sensory systems, manifesting as chronic paralysis, sensory changes, and pain disorders. The multi-faceted and heterogeneous nature of SCI has made effective rehabilitative strategies challenging. Work over the last 40 years has aimed to overcome these obstacles by harnessing the intrinsic plasticity of the spinal cord to improve functional locomotor recovery. Intensive training after SCI facilitates lower extremity function and has shown promise as a tool for retraining the spinal cord by engaging innate locomotor circuitry in the lumbar cord. As new training paradigms evolve, the importance of appropriate afferent input has emerged as a requirement for adaptive plasticity. The integration of kinematic, sensory, and loading force information must be closely monitored and carefully manipulated to optimize training outcomes. Inappropriate peripheral input may produce lasting maladaptive sensory and motor effects, such as central pain and spasticity. Thus, it is important to closely consider the type of afferent input the injured spinal cord receives. Here we review preclinical and clinical input parameters fostering adaptive plasticity, as well as those producing maladaptive plasticity that may undermine neurorehabilitative efforts. We differentiate between passive (hindlimb unloading [HU], limb immobilization) and active (peripheral nociception) forms of aberrant input. Furthermore, we discuss the timing of initiating exposure to afferent input after SCI for promoting functional locomotor recovery. We conclude by presenting a candidate rapid synaptic mechanism for maladaptive plasticity after SCI, offering a pharmacological target for restoring the capacity for adaptive spinal plasticity in real time.

Locomotor training with body weight support in SCI: EMG improvement is more optimally expressed at a low testing speed.

Science.gov (United States)

Meyns, P; Van de Crommert, H W A A; Rijken, H; van Kuppevelt, D H J M; Duysens, J

2014-12-01

Case series. To determine the optimal testing speed at which the recovery of the EMG (electromyographic) activity should be assessed during and after body weight supported (BWS) locomotor training. Tertiary hospital, Sint Maartenskliniek, Nijmegen, The Netherlands. Four participants with incomplete chronic SCI were included for BWS locomotor training; one AIS-C and three AIS-D (according to the ASIA (American Spinal Injury Association) Impairment Scale or AIS). All were at least 5 years after injury. The SCI participants were trained three times a week for a period of 6 weeks. They improved their locomotor function in terms of higher walking speed, less BWS and less assistance needed. To investigate which treadmill speed for EMG assessment reflects the functional improvement most adequately, all participants were assessed weekly using the same two speeds (0.5 and 1.5 km h(-1), referred to as low and high speed, respectively) for 6 weeks. The change in root mean square EMG (RMS EMG) was assessed in four leg muscles; biceps femoris, rectus femoris, gastrocnemius medialis and tibialis anterior. The changes in RMS EMG occurred at similar phases of the step cycle for both walking conditions, but these changes were larger when the treadmill was set at a low speed (0.5 km h(-1)). Improvement in gait is feasible with BWS treadmill training even long after injury. The EMG changes after treadmill training are more optimally expressed using a low rather than a high testing treadmill speed.

Running behavior and its energy cost in mice selectively bred for high voluntary locomotor activity.

Science.gov (United States)

Rezende, Enrico L; Gomes, Fernando R; Chappell, Mark A; Garland, Theodore

2009-01-01

Locomotion is central to behavior and intrinsic to many fitness-critical activities (e.g., migration, foraging), and it competes with other life-history components for energy. However, detailed analyses of how changes in locomotor activity and running behavior affect energy budgets are scarce. We quantified these effects in four replicate lines of house mice that have been selectively bred for high voluntary wheel running (S lines) and in their four nonselected control lines (C lines). We monitored wheel speeds and oxygen consumption for 24-48 h to determine daily energy expenditure (DEE), resting metabolic rate (RMR), locomotor costs, and running behavior (bout characteristics). Daily running distances increased roughly 50%-90% in S lines in response to selection. After we controlled for body mass effects, selection resulted in a 23% increase in DEE in males and a 6% increase in females. Total activity costs (DEE - RMR) accounted for 50%-60% of DEE in both S and C lines and were 29% higher in S males and 5% higher in S females compared with their C counterparts. Energetic costs of increased daily running distances differed between sexes because S females evolved higher running distances by running faster with little change in time spent running, while S males also spent 40% more time running than C males. This increase in time spent running impinged on high energy costs because the majority of running costs stemmed from "postural costs" (the difference between RMR and the zero-speed intercept of the speed vs. metabolic rate relationship). No statistical differences in these traits were detected between S and C females, suggesting that large changes in locomotor behavior do not necessarily effect overall energy budgets. Running behavior also differed between sexes: within S lines, males ran with more but shorter bouts than females. Our results indicate that selection effects on energy budgets can differ dramatically between sexes and that energetic constraints in S

See and be seen: Infant-caregiver social looking during locomotor free play.

Science.gov (United States)

Franchak, John M; Kretch, Kari S; Adolph, Karen E

2017-10-26

Face-to-face interaction between infants and their caregivers is a mainstay of developmental research. However, common laboratory paradigms for studying dyadic interaction oversimplify the act of looking at the partner's face by seating infants and caregivers face to face in stationary positions. In less constrained conditions when both partners are freely mobile, infants and caregivers must move their heads and bodies to look at each other. We hypothesized that face looking and mutual gaze for each member of the dyad would decrease with increased motor costs of looking. To test this hypothesis, 12-month-old crawling and walking infants and their parents wore head-mounted eye trackers to record eye movements of each member of the dyad during locomotor free play in a large toy-filled playroom. Findings revealed that increased motor costs decreased face looking and mutual gaze: Each partner looked less at the other's face when their own posture or the other's posture required more motor effort to gain visual access to the other's face. Caregivers mirrored infants' posture by spending more time down on the ground when infants were prone, perhaps to facilitate face looking. Infants looked more at toys than at their caregiver's face, but caregivers looked at their infant's face and at toys in equal amounts. Furthermore, infants looked less at toys and faces compared to studies that used stationary tasks, suggesting that the attentional demands differ in an unconstrained locomotor task. Taken together, findings indicate that ever-changing motor constraints affect real-life social looking. © 2017 John Wiley & Sons Ltd.

Supporting Dynamic Ad hoc Collaboration Capabilities

CERN Document Server

Agarwal, D

2003-01-01

Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively. Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment.

Supporting Dynamic Ad hoc Collaboration Capabilities

International Nuclear Information System (INIS)

Agarwal, Deborah A.; Berket, Karlo

2003-01-01

Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively. Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment

Elevated copper levels during larval development cause altered locomotor behavior in the adult carabid beetle Pterostichus cupreus L. (Coleoptera: Carbidae)

DEFF Research Database (Denmark)

Bayley, M; Baatrup, E; Heimbach, U

1995-01-01

behavior of adult Pterostichus cupreus carabid beetles was quantified after being raised on copper-contaminated food and soil during larval development. Copper was found to have an acute toxic effect measured in larval mortality, to cause a slight increase in the developmental period of males......It is generally believed that copper causes changes in carabid communities indirectly by reducing food availability, because these animals are frequently found to have only slightly elevated metal contents even close to pollution sources. Using computer-centered video tracking, the locomotor......, but not to effect the emergence weights of adults of either sex. This toxic effect on the larvae was preserved through pupation to the surviving adults, which were normal in size and appearance, but displayed a dramatically depressed locomotor behavior. Copper analysis of these adults revealed that copper levels...

Locomotor training with body weight support in SCI : EMG improvement is more optimally expressed at a low testing speed

NARCIS (Netherlands)

Meyns, P.; Van de Crommert, H. W. A. A.; Rijken, H.; van Kuppevelt, D. H. J. M.; Duysens, J.

2014-01-01

Study design: Case series. Objectives: To determine the optimal testing speed at which the recovery of the EMG (electromyographic) activity should be assessed during and after body weight supported (BWS) locomotor training. Setting: Tertiary hospital, Sint Maartenskliniek, Nijmegen, The Netherlands.

A three-dimensional morphometric analysis of upper forelimb morphology in the enigmatic tapir (Perissodactyla: Tapirus) hints at subtle variations in locomotor ecology.

Science.gov (United States)

MacLaren, Jamie A; Nauwelaerts, Sandra

2016-11-01

Forelimb morphology is an indicator for terrestrial locomotor ecology. The limb morphology of the enigmatic tapir (Perissodactyla: Tapirus) has often been compared to that of basal perissodactyls, despite the lack of quantitative studies comparing forelimb variation in modern tapirs. Here, we present a quantitative assessment of tapir upper forelimb osteology using three-dimensional geometric morphometrics to test whether the four modern tapir species are monomorphic in their forelimb skeleton. The shape of the upper forelimb bones across four species (T. indicus; T. bairdii; T. terrestris; T. pinchaque) was investigated. Bones were laser scanned to capture surface morphology and 3D landmark analysis was used to quantify shape. Discriminant function analyses were performed to reveal features which could be used for interspecific discrimination. Overall our results show that the appendicular skeleton contains notable interspecific differences. We demonstrate that upper forelimb bones can be used to discriminate between species (>91% accuracy), with the scapula proving the most diagnostic bone (100% accuracy). Features that most successfully discriminate between the four species include the placement of the cranial angle of the scapula, depth of the humeral condyle, and the caudal deflection of the olecranon. Previous studies comparing the limbs of T. indicus and T. terrestris are corroborated by our quantitative findings. Moreover, the mountain tapir T. pinchaque consistently exhibited the greatest divergence in morphology from the other three species. Despite previous studies describing tapirs as functionally mediportal in their locomotor style, we find osteological evidence suggesting a spectrum of locomotor adaptations in the tapirs. We conclude that modern tapir forelimbs are neither monomorphic nor are tapirs as conserved in their locomotor habits as previously described. J. Morphol. 277:1469-1485, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals

Effect and reporting bias of RhoA/ROCK-blockade intervention on locomotor recovery after spinal cord injury: a systematic review and meta-analysis.

Science.gov (United States)

Watzlawick, Ralf; Sena, Emily S; Dirnagl, Ulrich; Brommer, Benedikt; Kopp, Marcel A; Macleod, Malcolm R; Howells, David W; Schwab, Jan M

2014-01-01

Blockade of small GTPase-RhoA signaling pathway is considered a candidate translational strategy to improve functional outcome after spinal cord injury (SCI) in humans. Pooling preclinical evidence by orthodox meta-analysis is confounded by missing data (publication bias). To conduct a systematic review and meta-analysis of RhoA/Rho-associated coiled-coil containing protein kinase (ROCK) blocking approaches to (1) analyze the impact of bias that may lead to inflated effect sizes and (2) determine the normalized effect size of functional locomotor recovery after experimental thoracic SCI. We conducted a systematic search of PubMed, EMBASE, and Web of Science and hand searched related references. Studies were selected if they reported the effect of RhoA/ROCK inhibitors (C3-exoenzmye, fasudil, Y-27632, ibuprofen, siRhoA, and p21) in experimental spinal cord hemisection, contusion, or transection on locomotor recovery measured by the Basso, Beattie, and Bresnahan score or the Basso Mouse Scale for Locomotion. Two investigators independently assessed the identified studies. Details of individual study characteristics from each publication were extracted and effect sizes pooled using a random effects model. We assessed risk for bias using a 9-point-item quality checklist and calculated publication bias with Egger regression and the trim and fill method. A stratified meta-analysis was used to assess the impact of study characteristics on locomotor recovery. Thirty studies (725 animals) were identified. RhoA/ROCK inhibition was found to improve locomotor outcome by 21% (95% CI, 16.0-26.6). Assessment of publication bias by the trim and fill method suggested that 30% of experiments remain unpublished. Inclusion of these theoretical missing studies suggested a 27% overestimation of efficacy, reducing the overall efficacy to a 15% improvement in locomotor recovery. Low study quality was associated with larger estimates of neurobehavioral outcome. Taking into account

Service-Oriented Architecture Afloat: A Capabilities-Based Prioritization Scheme

Science.gov (United States)

2013-04-01

to “information superiority,” ultimately enhancing warfighting capability. Introduction The Program Executive Office for Command, Control...gateway architecture for IP satellite networks with dynamic resource mangement and DiffServ QoS provision. International Journal of Satellite

Regulation of Akt-mTOR, ubiquitin-proteasome and autophagy-lysosome pathways in locomotor and respiratory muscles during experimental sepsis in mice.

Science.gov (United States)

Morel, Jérome; Palao, Jean-Charles; Castells, Josiane; Desgeorges, Marine; Busso, Thierry; Molliex, Serge; Jahnke, Vanessa; Del Carmine, Peggy; Gondin, Julien; Arnould, David; Durieux, Anne Cécile; Freyssenet, Damien

2017-09-07

Sepsis induced loss of muscle mass and function contributes to promote physical inactivity and disability in patients. In this experimental study, mice were sacrificed 1, 4, or 7 days after cecal ligation and puncture (CLP) or sham surgery. When compared with diaphragm, locomotor muscles were more prone to sepsis-induced muscle mass loss. This could be attributed to a greater activation of ubiquitin-proteasome system and an increased myostatin expression. Thus, this study strongly suggests that the contractile activity pattern of diaphragm muscle confers resistance to atrophy compared to the locomotor gastrocnemius muscle. These data also suggest that a strategy aimed at preventing the activation of catabolic pathways and preserving spontaneous activity would be of interest for the treatment of patients with sepsis-induced neuromyopathy.

Differential neurotoxic effects of in utero and lactational exposure to hydroxylated polychlorinated biphenyl (OH-PCB 106) on spontaneous locomotor activity and motor coordination in young adult male mice.

Science.gov (United States)

Haijima, Asahi; Lesmana, Ronny; Shimokawa, Noriaki; Amano, Izuki; Takatsuru, Yusuke; Koibuchi, Noriyuki

2017-01-01

We investigated whether in utero or lactational exposure to 4-hydroxy-2',3,3',4',5'-pentachlorobiphenyl (OH-PCB 106) affects spontaneous locomotor activity and motor coordination in young adult male mice. For in utero exposure, pregnant C57BL/6J mice received 0.05 or 0.5 mg/kg body weight of OH-PCB 106 or corn oil vehicle via gavage every second day from gestational day 10 to 18. For lactational exposure, the different groups of dams received 0.05 or 0.5 mg/kg body weight of OH-PCB 106 or corn oil vehicle via gavage every second day from postpartum day 3 to 13. At 6-7 weeks of age, the spontaneous locomotor activities of male offspring were evaluated for a 24-hr continuous session in a home cage and in an open field for 30-min. Motor coordination function on an accelerating rotarod was also measured. Mice exposed prenatally to OH-PCB 106 showed increased spontaneous locomotor activities during the dark phase in the home cage and during the first 10-min in the open field compared with control mice. Mice exposed lactationally to OH-PCB 106, however, did not show a time-dependent decrease in locomotor activity in the open field. Instead, their locomotor activity increased significantly during the second 10-min block. In addition, mice exposed lactationally to OH-PCB 106 displayed impairments in motor coordination in the rotarod test. These results suggest that perinatal exposure to OH-PCB 106 affects motor behaviors in young adult male mice. Depending on the period of exposure, OH-PCB 106 may have different effects on neurobehavioral development.

Improvements in bladder, bowel and sexual outcomes following task-specific locomotor training in human spinal cord injury.

Directory of Open Access Journals (Sweden)

Charles H Hubscher

Full Text Available Locomotor training (LT as a therapeutic intervention following spinal cord injury (SCI is an effective rehabilitation strategy for improving motor outcomes, but its impact on non-locomotor functions is unknown. Given recent results of our labs' pre-clinical animal SCI LT studies and existing overlap of lumbosacral spinal circuitries controlling pelvic-visceral and locomotor functions, we addressed whether LT can improve bladder, bowel and sexual function in humans at chronic SCI time-points (> two years post-injury.Prospective cohort study; pilot trial with small sample size.Eight SCI research participants who were undergoing 80 daily one-hour sessions of LT on a treadmill using body-weight support, or one-hour of LT and stand training on alternate days, as part of another research study conducted at the Kentucky Spinal Cord Injury Research Center, University of Louisville, were enrolled in this pilot trial. Urodynamic assessments were performed and International Data Set questionnaire forms completed for bladder, bowel and sexual functions at pre-and post-training time points. Four usual care (non-trained; regular at-home routine research participants were also enrolled in this study and had the same assessments collected twice, at least 3 months apart.Filling cystometry documented significant increases in bladder capacity, voiding efficiency and detrusor contraction time as well as significant decreases in voiding pressure post-training relative to baseline. Questionnaires revealed a decrease in the frequency of nocturia and urinary incontinence for several research participants as well as a significant decrease in time required for defecation and a significant increase in sexual desire post-training. No significant differences were found for usual care research participants.These results suggest that an appropriate level of sensory information provided to the spinal cord, generated through task-specific stepping and/or loading, can positively

Integration of Descending Command Systems for the Generation of Context-Specific Locomotor Behaviors

Directory of Open Access Journals (Sweden)

Linda H. Kim

2017-10-01

Full Text Available Over the past decade there has been a renaissance in our understanding of spinal cord circuits; new technologies are beginning to provide key insights into descending circuits which project onto spinal cord central pattern generators. By integrating work from both the locomotor and animal behavioral fields, we can now examine context-specific control of locomotion, with an emphasis on descending modulation arising from various regions of the brainstem. Here we examine approach and avoidance behaviors and the circuits that lead to the production and arrest of locomotion.

Gait Dynamics and Locomotor Metabolism

Science.gov (United States)

2014-12-01

26 47. Taylor CR, Heglund NC, Maloiy GMO . Energetics and mechanics of terrestrial locomotion. I. Metabolic energy consumption as a function of...San Diego, CA: Academic Press, 1994. 110 47. Taylor CR, Heglund NC, Maloiy GMO . Energetics and mechanics of terrestrial locomotion. I. Metabolic

[The experience with the application of the selective electro-stimulation impacts in the children presenting with the disturbances of the locomotor function].

Science.gov (United States)

Vlasenko, A V; Mikhnovich, V I; Machanskaya, A V; Pogodina, A V; Bugun, O V; Rychkova, L V; Astakhova, T A

2017-12-28

The objective of the present study was the improvement of the effectiveness of medical rehabilitation of the children presenting with the disturbances of the locomotor function using a «LymphaVision» apparatus for the selective electrical stimulation. The study included 42 patients with movement disorders divided into two groups depending on the method of non-drug therapy. The main group was comprised of the patients receiving the treatment by electrical stimulation with the use of the «LymphaVision» apparatus while the remaining patients made up the group of comparison (they were treated with by means of Vermel electrophoresis with the use of a 1% sodium bromide solution). The increase of the muscular strength evaluated based on the scoring system and the number of motor skills were used as the criteria of the effectiveness of the treatment. The applied Statistica for Windows package, version 6.0 («StatSoft», USA). Was employed for the statistical analysis of the data obtained. The significance and number of differences between two independent samples of the quantitative features were assessed using the Mann-Whitney U test. The Wilcoxon matched pairs test was used to compare the two matched groups. The children comprising the group treated by means of selective exposure to electrical stimulation with the use of the «LymphaVision» apparatus in the course of the rehabilitation process exhibited a significant increase in the strength of the muscles of the lower extremities and the trunk over the baseline values (p=0.003 and p=0.04 respectively) and acquired a significantly greater number of the new motor skills (p=0.02). The application of the proposed method is characterized by the highly pronounced clinical efficiency. This approach is pathogenetically well-substantiated for the treatment of the children presenting with the locomotor disorders developing as the consequences of perinatal lesions in the central nervous system and promotes the restoration of

Control of locomotor stability in stabilizing and destabilizing environments.

Science.gov (United States)

Wu, Mengnan/Mary; Brown, Geoffrey; Gordon, Keith E

2017-06-01

To develop effective interventions targeting locomotor stability, it is crucial to understand how people control and modify gait in response to changes in stabilization requirements. Our purpose was to examine how individuals with and without incomplete spinal cord injury (iSCI) control lateral stability in haptic walking environments that increase or decrease stabilization demands. We hypothesized that people would adapt to walking in a predictable, stabilizing viscous force field and unpredictable destabilizing force field by increasing and decreasing feedforward control of lateral stability, respectively. Adaptations in feedforward control were measured using after-effects when fields were removed. Both groups significantly (pfeedforward adaptions to increase control of lateral stability. In contrast, in the destabilizing field, non-impaired subjects increased movement variability (p0.05). When the destabilizing field was removed, increases in movement variability persisted (pfeedforward decreases in resistance to perturbations. Published by Elsevier B.V.

A Multiposture Locomotor Training Device with Force-Field Control

Directory of Open Access Journals (Sweden)

Jianfeng Sui

2014-11-01

Full Text Available This paper introduces a multiposture locomotor training device (MPLTD with a closed-loop control scheme based on joint angle feedback, which is able to overcome various difficulties resulting from mechanical vibration and the weight of trainer to achieve higher accuracy trajectory. By introducing the force-field control scheme used in the closed-loop control, the device can obtain the active-constrained mode including the passive one. The MPLTD is mainly composed of three systems: posture adjusting and weight support system, lower limb exoskeleton system, and control system, of which the lower limb exoskeleton system mainly includes the indifferent equilibrium mechanism with two degrees of freedom (DOF and the driving torque is calculated by the Lagrangian function. In addition, a series of experiments, the weight support and the trajectory accuracy experiment, demonstrate a good performance of mechanical structure and the closed-loop control.

Chronic low-level arsenic exposure causes gender-specific alterations in locomotor activity, dopaminergic systems, and thioredoxin expression in mice

International Nuclear Information System (INIS)

Bardullas, U.; Limon-Pacheco, J.H.; Giordano, M.; Carrizales, L.; Mendoza-Trejo, M.S.; Rodriguez, V.M.

2009-01-01

Arsenic (As) is a toxic metalloid widely present in the environment. Human exposure to As has been associated with the development of skin and internal organ cancers and cardiovascular disorders, among other diseases. A few studies report decreases in intelligence quotient (IQ), and sensory and motor alterations after chronic As exposure in humans. On the other hand, studies of rodents exposed to high doses of As have found alterations in locomotor activity, brain neurochemistry, behavioral tasks, and oxidative stress. In the present study both male and female C57Bl/6J mice were exposed to environmentally relevant doses of As such as 0.05, 0.5, 5.0, or 50 mg As/L of drinking water for 4 months, and locomotor activity was assessed every month. Male mice presented hyperactivity in the group exposed to 0.5 mg As/L and hypoactivity in the group exposed to 50 mg As/L after 4 months of As exposure, whereas female mice exposed to 0.05, 0.5, and 5.0 mg As/L exhibited hyperactivity in every monthly test during As exposure. Furthermore, striatal and hypothalamic dopamine content was decreased only in female mice. Also decreases in tyrosine hydroxylase (TH) and cytosolic thioredoxin (Trx-1) mRNA expression in striatum and nucleus accumbens were observed in male and female mice, respectively. These results indicate that chronic As exposure leads to gender-dependent alterations in dopaminergic markers and spontaneous locomotor activity, and down-regulation of the antioxidant capacity of the brain.

Organizational knowledge and capabilities in healthcare: Deconstructing and integrating diverse perspectives

Science.gov (United States)

Evans, Jenna M; Brown, Adalsteinn; Baker, G Ross

2017-01-01

Diverse concepts and bodies of work exist in the academic literature to guide research and practice on organizational knowledge and capabilities. However, these concepts have largely developed in parallel with minimal cross-fertilization, particularly in the healthcare domain. This contributes to confusion regarding conceptual boundaries and relationships, and to a lack of application of potentially useful evidence. The aim of this article is to assess three concepts associated with organizational knowledge content—intellectual capital, organizational core competencies, and dynamic capabilities—and to propose an agenda for future research. We conducted a literature review to identify and synthesize papers that apply the concepts of intellectual capital, organizational core competencies, and dynamic capabilities in healthcare settings. We explore the meaning of these concepts, summarize and critique associated healthcare research, and propose a high-level framework for conceptualizing how the concepts are related to each other. To support application of the concepts in practice, we conducted a case study of a healthcare organization. Through document review and interviews with current and former leaders, we identify and describe the organization’s intellectual capital, organizational core competencies, and dynamic capabilities. The review demonstrates that efforts to identify, understand, and improve organizational knowledge have been limited in health services research. In the literature on healthcare, we identified 38 papers on intellectual capital, 4 on core competencies, and 5 on dynamic capabilities. We link these disparate fields of inquiry by conceptualizing the three concepts as distinct, but overlapping concepts influenced by broader organizational learning and knowledge management processes. To aid healthcare researchers in studying and applying a knowledge-based view of organizational performance, we propose an agenda for future research involving

Modern principles of prevention of anophthalmic syndrome: formation of the locomotor stump, the types of orbital implants

Directory of Open Access Journals (Sweden)

I. V. Zapuskalov

2017-01-01

Full Text Available This article analyzes the current state of the problem of the correction of anophthalmic syndrome. Evaluated various methods of formation of the locomotor stump after removal of the eyeball, gave a detailed description of different types of materials for the fabrication of orbital implant, as well as reflect the basic principles of prevention of complications.

Neural network fusion capabilities for efficient implementation of tracking algorithms

Science.gov (United States)

Sundareshan, Malur K.; Amoozegar, Farid

1997-03-01

The ability to efficiently fuse information of different forms to facilitate intelligent decision making is one of the major capabilities of trained multilayer neural networks that is now being recognized. While development of innovative adaptive control algorithms for nonlinear dynamical plants that attempt to exploit these capabilities seems to be more popular, a corresponding development of nonlinear estimation algorithms using these approaches, particularly for application in target surveillance and guidance operations, has not received similar attention. We describe the capabilities and functionality of neural network algorithms for data fusion and implementation of tracking filters. To discuss details and to serve as a vehicle for quantitative performance evaluations, the illustrative case of estimating the position and velocity of surveillance targets is considered. Efficient target- tracking algorithms that can utilize data from a host of sensing modalities and are capable of reliably tracking even uncooperative targets executing fast and complex maneuvers are of interest in a number of applications. The primary motivation for employing neural networks in these applications comes from the efficiency with which more features extracted from different sensor measurements can be utilized as inputs for estimating target maneuvers. A system architecture that efficiently integrates the fusion capabilities of a trained multilayer neural net with the tracking performance of a Kalman filter is described. The innovation lies in the way the fusion of multisensor data is accomplished to facilitate improved estimation without increasing the computational complexity of the dynamical state estimator itself.

Behavioral and Locomotor Measurements Using an Open Field Activity Monitoring System for Skeletal Muscle Diseases

OpenAIRE

Tatem, Kathleen S.; Quinn, James L.; Phadke, Aditi; Yu, Qing; Gordish-Dressman, Heather; Nagaraju, Kanneboyina

2014-01-01

The open field activity monitoring system comprehensively assesses locomotor and behavioral activity levels of mice. It is a useful tool for assessing locomotive impairment in animal models of neuromuscular disease and efficacy of therapeutic drugs that may improve locomotion and/or muscle function. The open field activity measurement provides a different measure than muscle strength, which is commonly assessed by grip strength measurements. It can also show how drugs may affect other body sy...

Eating high fat chow decreases dopamine clearance in adolescent and adult male rats but selectively enhances the locomotor stimulating effects of cocaine in adolescents.

Science.gov (United States)

Baladi, Michelle G; Horton, Rebecca E; Owens, William A; Daws, Lynette C; France, Charles P

2015-03-24

Feeding conditions can influence dopamine neurotransmission and impact behavioral and neurochemical effects of drugs acting on dopamine systems. This study examined whether eating high fat chow alters the locomotor effects of cocaine and dopamine transporter activity in adolescent (postnatal day 25) and adult (postnatal day 75) male Sprague-Dawley rats. Dose-response curves for cocaine-induced locomotor activity were generated in rats with free access to either standard or high fat chow or restricted access to high fat chow (body weight matched to rats eating standard chow). Compared with eating standard chow, eating high fat chow increased the sensitivity of adolescent, but not adult, rats to the acute effects of cocaine. When tested once per week, sensitization to the locomotor effects of cocaine was enhanced in adolescent rats eating high fat chow compared with adolescent rats eating standard chow. Sensitization to cocaine was not different among feeding conditions in adults. When adolescent rats that previously ate high fat chow ate standard chow, sensitivity to cocaine returned to normal. As measured by chronoamperometry, dopamine clearance rate in striatum was decreased in both adolescent and adult rats eating high fat chow compared with age-matched rats eating standard chow. These results suggest that high fat diet-induced reductions in dopamine clearance rate do not always correspond to increased sensitivity to the locomotor effects of cocaine, suggesting that mechanisms other than dopamine transporter might play a role. Moreover, in adolescent but not adult rats, eating high fat chow increases sensitivity to cocaine and enhances the sensitization that develops to cocaine. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Locomotor and Heart Rate Responses of Floaters During Small-Sided Games in Elite Soccer Players: Effect of Pitch Size and Inclusion of Goal Keepers.

Science.gov (United States)

Lacome, Mathieu; Simpson, Ben M; Cholley, Yannick; Buchheit, Martin

2017-09-27

To (1) compare the locomotor and heart rate responses between floaters and regular players during both small and large small sided games (SSGs) and (2) examine whether the type of game (i.e., game simulation vs possession game) affects the magnitude of the difference between floaters and regular players. Data were collected in 41 players belonging to an elite French football team during three consecutive seasons (2014-2017). 5-Hz GPS were used to collect all training data, with the Athletic Data Innovation analyser (v5.4.1.514, Sydney, Australia) used to derive total distance (m), high-speed distance (> 14.4 km.h -1 , m) and external mechanical load (MechL, a.u). All SSGs included exclusively one floater, and were divided into two main categories, according to the participation of goal-keepers (GK) (game simulation, GS) or not (possession games, PO) and then further divided into small and large (>100 m2/player) SSGs based on the area per player ratio. Locomotor activity and mechanical load performed were likely-to-most likely lower (moderate to large magnitude) in floaters compared with regular players, while differences in HR responses were unclear to possibly higher (small) in floaters. The magnitude of the difference in locomotor activity and MechL between floaters and regular players was substantially greater during GS compared with PO. Compared with regular players, floaters present decreased external load (both locomotor and MechL) despite unclear to possibly slightly higher HR responses during SSGs. Moreover, the responses of floaters compared with regular players are not consistent across different sizes of SSGs, with greater differences during GS than PO.

Cocaine- and amphetamine-regulated transcript peptide in the nucleus accumbens shell inhibits cocaine-induced locomotor sensitization to transient over-expression of α-Ca2+ /calmodulin-dependent protein kinase II.

Science.gov (United States)

Xiong, Lixia; Meng, Qing; Sun, Xi; Lu, Xiangtong; Fu, Qiang; Peng, Qinghua; Yang, Jianhua; Oh, Ki-Wan; Hu, Zhenzhen

2018-01-04

Cocaine- and amphetamine-regulated transcript (CART) peptide is a widely distributed neurotransmitter that attenuates cocaine-induced locomotor activity when injected into the nucleus accumbens (NAc). Our previous work first confirmed that the inhibitory mechanism of the CART peptide on cocaine-induced locomotor activity is related to a reduction in cocaine-enhanced phosphorylated Ca 2+ /calmodulin-dependent protein kinaseIIα (pCaMKIIα) and the enhancement of cocaine-induced D3R function. This study investigated whether CART peptide inhibited cocaine-induced locomotor activity via inhibition of interactions between pCaMKIIα and the D3 dopamine receptor (D3R). We demonstrated that lentivirus-mediated gene transfer transiently increased pCaMKIIα expression, which peaked at 10 days after microinjection into the rat NAc shell, and induced a significant increase in Ca 2+ influx along with greater behavioral sensitivity in the open field test after intraperitoneal injections of cocaine (15 mg/kg). However, western blot analysis and coimmunoprecipitation demonstrated that CART peptide treatment in lentivirus-transfected CaMKIIα-over-expressing NAc rat tissues or cells prior to cocaine administration inhibited the cocaine-induced Ca 2+ influx and attenuated the cocaine-increased pCaMKIIα expression in lentivirus-transfected CaMKIIα-over-expressing cells. CART peptide decreased the cocaine-enhanced phosphorylated cAMP response element binding protein (pCREB) expression via inhibition of the pCaMKIIα-D3R interaction, which may account for the prolonged locomotor sensitization induced by repeated cocaine treatment in lentivirus-transfected CaMKIIα-over-expressing cells. These results provide strong evidence for the inhibitory modulation of CART peptide in cocaine-induced locomotor sensitization. © 2018 International Society for Neurochemistry.

Clinical efficiency of roentgenopaque study of muscles in patients with disorders of locomotor system

International Nuclear Information System (INIS)

D'yachkova, G.V.

1996-01-01

Radiopaque studies of soft tissues in patients with disorders and diseases of locomotor system in the case of perosseous osteosynthesis were performed. To correct the diagnosis, control the soft tissue state during treatment, assess its results more than 1000 radiopaque studies of muscles were conducted. Application of the radiopaque studies of femur muscles in patients with extension contractures of knee joint permitted to specify the character of contracture, to determine the character of muscles changes in patients with immobilization and arthrogenetic contractures which depended on disease duration

Impairment of the organization of locomotor and exploratory behaviors in bile duct-ligated rats

DEFF Research Database (Denmark)

Leke, Renata; de Oliveira, Diogo L; Mussulini, Ben Hur M.

2012-01-01

Hepatic encephalopathy (HE) arises from acute or chronic liver diseases and leads to several problems, including motor impairment. Animal models of chronic liver disease have extensively investigated the mechanisms of this disease. Impairment of locomotor activity has been described in different...... female Wistar rats underwent common bile duct ligation (BDL rats) or the manipulation of common bile duct without ligation (control rats). Six weeks after surgery, control and BDL rats underwent open-field, plus-maze and foot-fault behavioral tasks. The BDL rats developed chronic liver failure...

Dissolution Dynamic Nuclear Polarization capability study with fluid path

DEFF Research Database (Denmark)

Malinowski, Ronja Maja; Lipsø, Hans Kasper Wigh; Lerche, Mathilde Hauge

2016-01-01

Signal enhancement by hyperpolarization is a way of overcoming the low sensitivity in magnetic resonance; MRI in particular. One of the most well-known methods, dissolution Dynamic Nuclear Polarization, has been used clinically in cancer patients. One way of ensuring a low bioburden of the hyperp......Signal enhancement by hyperpolarization is a way of overcoming the low sensitivity in magnetic resonance; MRI in particular. One of the most well-known methods, dissolution Dynamic Nuclear Polarization, has been used clinically in cancer patients. One way of ensuring a low bioburden...... of the hyperpolarized product is by use of a closed fluid path that constitutes a barrier to contamination. The fluid path can be filled with the pharmaceuticals, i.e. imaging agent and solvents, in a clean room, and then stored or immediately used at the polarizer. In this study, we present a method of filling...

Disentangling the effects of organizational capabilities, innovation and firm size on SME sales growth

NARCIS (Netherlands)

Uhlaner, Lorraine M.; van Stel, Andre; Duplat, Valerie; Zhou, Haibo

2013-01-01

This paper focuses on certain drivers of SME sales growth related to knowledge and innovation. Building on the dynamic capabilities literature, we test whether two organizational capabilities (external sourcing and employee involvement in renewal activities) predict sales growth, and if so, whether

Modulation of spontaneous locomotor and respiratory drives to hindlimb motoneurons temporally related to sympathetic drives as revealed by Mayer waves

DEFF Research Database (Denmark)

Wienecke, Jacob; Denton, Manuel Enríquez; Stecina, Katinka

2015-01-01

In this study we investigated how the networks mediating respiratory and locomotor drives to lumbar motoneurons interact and how this interaction is modulated in relation to periodic variations in blood pressure (Mayer waves). Seven decerebrate cats, under neuromuscular blockade, were used to stu...

Capturing Firms’ Heterogeneity through Marketing and IT Capabilities in SMEs

Directory of Open Access Journals (Sweden)

María A. Ramón-Jerónimo

2017-11-01

Full Text Available To achieve sustainability, firms capable of surviving economic recessions is of key relevance; the capabilities that firms need to face dynamic environments remain an open question. In this work, a new procedure is proposed to capture firms’ heterogeneity with regard to the capabilities they possess in operating efficiently in dynamic environments. This approach enables the identification of the classes of firms that develop efficiency with a specific integration of resources. While the literature has most often measured firm capabilities using subjective measures, this study suggests the use of Data Envelopment Analysis to capture the ability to transform resources into outcomes and of Latent Class Regression to capture differences across firms that explain firms’ heterogeneity in the way they perform. By combining these two techniques, this work presents a way to identify those firms that need to invest in and develop certain capabilities. This work analyses a large dataset of manufacturing Small Medium Enterprises (SMEs extracted from the Business and Strategy survey provided by Fundación de la Sociedad Estatal de Participaciones Industriales( SEPI in Spain. The dataset used enfolds 10,960 observations from 2048 firms during the period 1994–2011. The complete dataset has been employed to calculate manufacturing firms’ efficiency. In a second step, data were cleaned to eliminate outliers, and to identify SMEs and observations with records of IT capabilities. As a result, 329 manufacturing SMEs were analysed to capture their heterogeneity. The results contribute to the current literature by explaining how manufacturing SMEs show a different need in their development of capabilities to be efficient and adapt to environmental changes. While approximately 20% of firms analysed really take advantage of recessions through their investment in R&D, the remaining 80% need to adjust their size or invest in IT capabilities to become competitive

Comparative potentialities of X-ray and remote thermographic diagnosis of locomotor system diseases and injuries

International Nuclear Information System (INIS)

Rozenfel'd, L.G.; Ternovoj, N.K.; Samokhin, A.V.; Likhosherst, E.K.

1988-01-01

The advisability of applying remote infrared tomography to diagnoze locomotor system diseases and injuries is substantiated. 764 patients with different bone and tissue system diseases and injuries are examined. Thermosemiotics in the case of deforming arthrosis of knee and hip joints, inflammatory diseases of joints of various ethiologies, acute chronic osteomyelitis and its exacerbation, is described. The place of remote infrared thermography in the complecx diagnostic examination of a given contingent of patients, is determined. 6 refs.; 4 figs

Modeling spatial navigation in the presence of dynamic obstacles: a differential games approach.

Science.gov (United States)

Darekar, Anuja; Goussev, Valery; McFadyen, Bradford J; Lamontagne, Anouk; Fung, Joyce

2018-03-01

Obstacle circumvention strategies can be shaped by the dynamic interaction of an individual (evader) and an obstacle (pursuer). We have developed a mathematical model with predictive and emergent components, using experimental data from seven healthy young adults walking toward a target while avoiding collision with a stationary or moving obstacle (approaching head-on, or diagonally 30° left or right) in a virtual environment. Two linear properties from the predictive component enable the evader to predict the minimum distance between itself and the obstacle at all times, including the future intersection of trajectories. The emergent component uses the classical differential games model to solve for an optimal circumvention while reaching the target, wherein the locomotor strategy is influenced by the obstacle, target, and the evader velocity. Both model components were fitted to a different set of experimental data obtained from five poststroke and healthy participants to derive the minimum predicted distance (predictive component) and obstacle influence dimensions (emergent component) during circumvention. Minimum predicted distance between evader and pursuer was kept constant when the evader was closest to the obstacle in all participants. Obstacle influence dimensions varied depending on obstacle approach condition and preferred side of circumvention, reflecting differences in locomotor strategies between poststroke and healthy individuals. Additionally, important associations between model outputs and observed experimental outcomes were found. The model, supported by experimental data, suggests that both predictive and emergent processes can shape obstacle circumvention strategies in healthy and poststroke individuals. NEW & NOTEWORTHY Obstacle circumvention during goal-directed locomotion is modeled with a new mathematical approach comprising both predictive and emergent elements. The major novelty is using differential games solutions to illustrate the

Satisfaction and perceptions of long-term manual wheelchair users with a spinal cord injury upon completion of a locomotor training program with an overground robotic exoskeleton.

Science.gov (United States)

Gagnon, Dany H; Vermette, Martin; Duclos, Cyril; Aubertin-Leheudre, Mylène; Ahmed, Sara; Kairy, Dahlia

2017-12-19

The main objectives of this study were to quantify clients' satisfaction and perception upon completion of a locomotor training program with an overground robotic exoskeleton. A group of 14 wheelchair users with a spinal cord injury, who finished a 6-8-week locomotor training program with the robotic exoskeleton (18 training sessions), were invited to complete a web-based electronic questionnaire. This questionnaire encompassed 41 statements organized around seven key domains: overall satisfaction related to the training program, satisfaction related to the overground robotic exoskeleton, satisfaction related to the program attributes, perceived learnability, perceived health benefits and risks and perceived motivation to engage in physical activity. Each statement was rated using a visual analogue scale ranging from "0 = totally disagree" to "100 = completely agree". Overall, respondents unanimously considered themselves satisfied with the locomotor training program with the robotic exoskeleton (95.7 ± 0.7%) and provided positive feedback about the robotic exoskeleton itself (82.3 ± 6.9%), the attributes of the locomotor training program (84.5 ± 6.9%) and their ability to learn to perform sit-stand transfers and walk with the robotic exoskeleton (79.6 ± 17%). Respondents perceived some health benefits (67.9 ± 16.7%) and have reported no fear of developing secondary complications or of potential risk for themselves linked to the use of the robotic exoskeleton (16.7 ± 8.2%). At the end of the program, respondents felt motivated to engage in a regular physical activity program (91.3 ± 0.1%). This study provides new insights on satisfaction and perceptions of wheelchair users while also confirming the relevance to continue to improve such technologies, and informing the development of future clinical trials. Implications for Rehabilitation All long-term manual wheelchair users with a spinal cord injury who participated in the

Comparison of capability of dynamic O2-enhanced MRI and quantitative thin-section MDCT to assess COPD in smokers

International Nuclear Information System (INIS)

Ohno, Yoshiharu; Koyama, Hisanobu; Yoshikawa, Takeshi; Matsumoto, Keiko; Aoyama, Nobukazu; Onishi, Yumiko; Takenaka, Daisuke; Matsumoto, Sumiaki; Nishimura, Yoshihiro; Sugimura, Kazuro

2012-01-01

Purpose: The purpose of this study was to directly and prospectively compare the capability of dynamic O 2 -enhanced MRI and quantitatively assessed thin-section MDCT to assess smokers’ COPD in a large prospective cohort. Materials and methods: The GOLD criteria for smokers were used to classify 187 smokers into four clinical stage groups as follows: smokers without COPD (n = 56) and with mild (n = 54), moderate (n = 52) and severe or very severe COPD (n = 24). All smokers underwent dynamic O 2 -enhanced MRI, MDCT and pulmonary function tests. Mean relative enhancement ratio and mean wash-in time on MRI and CT-based functional lung volume (CT-based FLV) as well as the ratio of airway wall area to total airway area on MDCT were computationally calculated. Then, all indexes were significantly correlated with functional parameters. To determine the efficacy of all indexes for clinical stage classification, the indexes for the four clinical groups were statistically compared by using Tukey's honestly significant difference multiple comparison test. Results: All indexes had significant correlations with functional parameters (p 2 -enhanced MRI for assessment of COPD in smokers is potentially as efficacious as quantitatively assessed thin-section MDCT.

Improved clinical status, quality of life, and walking capacity in Parkinson's disease after body weight-supported high-intensity locomotor training

DEFF Research Database (Denmark)

Rose, Martin Høyer; Løkkegaard, Annemette; Sonne-Holm, Stig

2013-01-01

OBJECTIVE: To evaluate the effect of body weight-supported progressive high-intensity locomotor training in Parkinson's disease (PD) on (1) clinical status; (2) quality of life; and (3) gait capacity. DESIGN: Open-label, fixed sequence crossover study. SETTING: University motor control laboratory......±93 to 637±90m. CONCLUSIONS: Body weight-supported progressive high-intensity locomotor training is feasible and well tolerated by patients with PD. The training improved clinical status, quality of life, and gait capacity significantly....... were found in all outcome measures compared with the control period. Total MDS-UPDRS score changed from (mean ± 1SD) 58±18 to 47±18, MDS-UPDRS motor part score changed from 35±10 to 29±12, PDQ-39 summary index score changed from 22±13 to 13±12, and the six-minute walking distance changed from 576...

Power capability evaluation for lithium iron phosphate batteries based on multi-parameter constraints estimation

Science.gov (United States)

Wang, Yujie; Pan, Rui; Liu, Chang; Chen, Zonghai; Ling, Qiang

2018-01-01

The battery power capability is intimately correlated with the climbing, braking and accelerating performance of the electric vehicles. Accurate power capability prediction can not only guarantee the safety but also regulate driving behavior and optimize battery energy usage. However, the nonlinearity of the battery model is very complex especially for the lithium iron phosphate batteries. Besides, the hysteresis loop in the open-circuit voltage curve is easy to cause large error in model prediction. In this work, a multi-parameter constraints dynamic estimation method is proposed to predict the battery continuous period power capability. A high-fidelity battery model which considers the battery polarization and hysteresis phenomenon is presented to approximate the high nonlinearity of the lithium iron phosphate battery. Explicit analyses of power capability with multiple constraints are elaborated, specifically the state-of-energy is considered in power capability assessment. Furthermore, to solve the problem of nonlinear system state estimation, and suppress noise interference, the UKF based state observer is employed for power capability prediction. The performance of the proposed methodology is demonstrated by experiments under different dynamic characterization schedules. The charge and discharge power capabilities of the lithium iron phosphate batteries are quantitatively assessed under different time scales and temperatures.

Stereoselective Effects of Abused “Bath Salt” Constituent 3,4-Methylenedioxypyrovalerone in Mice: Drug Discrimination, Locomotor Activity, and Thermoregulation

Science.gov (United States)

Gannon, Brenda M.; Williamson, Adrian; Suzuki, Masaki; Rice, Kenner C.

2016-01-01

3,4-Methylenedioxypyrovalerone (MDPV) is a common constituent of illicit “bath salts” products. MDPV is a chiral molecule, but the contribution of each enantiomer to in vivo effects in mice has not been determined. To address this, mice were trained to discriminate 10 mg/kg cocaine from saline, and substitutions with racemic MDPV, S(+)-MDPV, and R(−)-MDPV were performed. Other mice were implanted with telemetry probes to monitor core temperature and locomotor responses elicited by racemic MDPV, S(+)-MDPV, and R(−)-MDPV under a warm (28°C) or cool (20°C) ambient temperature. Mice reliably discriminated the cocaine training dose from saline, and each form of MDPV fully substituted for cocaine, although marked potency differences were observed such that S(+)-MDPV was most potent, racemic MDPV was less potent than the S(+) enantiomer, and R(−)-MDPV was least potent. At both ambient temperatures, locomotor stimulant effects were observed after doses of S(+)-MDPV and racemic MDPV, but R(−)-MDPV did not elicit locomotor stimulant effects at any tested dose. Interestingly, significant increases in maximum core body temperature were only observed after administration of racemic MDPV in the warm ambient environment; neither MDPV enantiomer altered core temperature at any dose tested, at either ambient temperature. These studies suggest that all three forms of MDPV induce biologic effects, but R(−)-MDPV is less potent than S(+)-MDPV and racemic MDPV. Taken together, these data suggest that the S(+)-MDPV enantiomer is likely responsible for the majority of the biologic effects of the racemate and should be targeted in therapeutic efforts against MDPV overdose and abuse. PMID:26769917

Gender-specific alteration of energy balance and circadian locomotor activity in the Crtc1 knockout mouse model of depression

KAUST Repository

Rossetti, Clara

2017-12-06

Obesity and depression are major public health concerns, and there is increasing evidence that they share etiological mechanisms. CREB-regulated transcription coactivator 1 (CRTC1) participates in neurobiological pathways involved in both mood and energy balance regulation. Crtc1 -/- mice rapidly develop a depressive-like and obese phenotype in early adulthood, and are therefore a relevant animal model to explore possible common mechanisms underlying mood disorders and obesity. Here, the obese phenotype of male and female Crtc1 -/- mice was further characterized by investigating CRTC1\\'s role in the homeostatic and hedonic regulation of food intake, as well as its influence on daily locomotor activity. Crtc1 -/- mice showed a strong gender difference in the homeostatic regulation of energy balance. Mutant males were hyperphagic and rapidly developed obesity on normal chow diet, whereas Crtc1 -/- females exhibited mild late-onset obesity without hyperphagia. Overeating of mutant males was accompanied by alterations in the expression of several orexigenic and anorexigenic hypothalamic genes, thus confirming a key role of CRTC1 in the central regulation of food intake. No alteration in preference and conditioned response for saccharine was observed in Crtc1 -/- mice, suggesting that mutant males\\' hyperphagia was not due to an altered hedonic regulation of food intake. Intriguingly, mutant males exhibited a hyperphagic behavior only during the resting (diurnal) phase of the light cycle. This abnormal feeding behavior was associated with a higher diurnal locomotor activity indicating that the lack of CRTC1 may affect circadian rhythmicity. Collectively, these findings highlight the male-specific involvement of CRTC1 in the central control of energy balance and circadian locomotor activity.

Gender-specific alteration of energy balance and circadian locomotor activity in the Crtc1 knockout mouse model of depression

KAUST Repository

Rossetti, Clara; Sciarra, Daniel; Petit, Jean-Marie; Eap, Chin B.; Halfon, Olivier; Magistretti, Pierre J.; Boutrel, Benjamin; Cardinaux, Jean-René

2017-01-01

Obesity and depression are major public health concerns, and there is increasing evidence that they share etiological mechanisms. CREB-regulated transcription coactivator 1 (CRTC1) participates in neurobiological pathways involved in both mood and energy balance regulation. Crtc1 -/- mice rapidly develop a depressive-like and obese phenotype in early adulthood, and are therefore a relevant animal model to explore possible common mechanisms underlying mood disorders and obesity. Here, the obese phenotype of male and female Crtc1 -/- mice was further characterized by investigating CRTC1's role in the homeostatic and hedonic regulation of food intake, as well as its influence on daily locomotor activity. Crtc1 -/- mice showed a strong gender difference in the homeostatic regulation of energy balance. Mutant males were hyperphagic and rapidly developed obesity on normal chow diet, whereas Crtc1 -/- females exhibited mild late-onset obesity without hyperphagia. Overeating of mutant males was accompanied by alterations in the expression of several orexigenic and anorexigenic hypothalamic genes, thus confirming a key role of CRTC1 in the central regulation of food intake. No alteration in preference and conditioned response for saccharine was observed in Crtc1 -/- mice, suggesting that mutant males' hyperphagia was not due to an altered hedonic regulation of food intake. Intriguingly, mutant males exhibited a hyperphagic behavior only during the resting (diurnal) phase of the light cycle. This abnormal feeding behavior was associated with a higher diurnal locomotor activity indicating that the lack of CRTC1 may affect circadian rhythmicity. Collectively, these findings highlight the male-specific involvement of CRTC1 in the central control of energy balance and circadian locomotor activity.

Structural Capability of an Organization toward Innovation Capability

DEFF Research Database (Denmark)

Nielsen, Susanne Balslev; Momeni, Mostafa

2016-01-01

The scholars in the field of strategic management have developed two major approaches for attainment of competitive advantage: an approach based on environmental opportunities, and another one based on internal capabilities of an organization. Some investigations in the last two decades have...... indicated that the advantages relying on the internal capabilities of organizations may determine the competitive position of organizations better than environmental opportunities do. Characteristics of firms shows that one of the most internal capabilities that lead the organizations to the strongest...... competitive advantage in the organizations is the innovation capability. The innovation capability is associated with other organizational capabilities, and many organizations have focused on the need to identify innovation capabilities.This research focuses on recognition of the structural aspect...

"On the Fence" versus "All in": Insights from Turtles for the Evolution of Aquatic Locomotor Specializations and Habitat Transitions in Tetrapod Vertebrates.

Science.gov (United States)

Blob, Richard W; Mayerl, Christopher J; Rivera, Angela R V; Rivera, Gabriel; Young, Vanessa K H

2016-12-01

Though ultimately descended from terrestrial amniotes, turtles have deep roots as an aquatic lineage and are quite diverse in the extent of their aquatic specializations. Many taxa can be viewed as "on the fence" between aquatic and terrestrial realms, whereas others have independently hyperspecialized and moved "all in" to aquatic habitats. Such differences in specialization are reflected strongly in the locomotor system. We have conducted several studies to evaluate the performance consequences of such variation in design, as well as the mechanisms through which specialization for aquatic locomotion is facilitated in turtles. One path to aquatic hyperspecialization has involved the evolutionary transformation of the forelimbs from rowing, tubular limbs with distal paddles into flapping, flattened flippers, as in sea turtles. Prior to the advent of any hydrodynamic advantages, the evolution of such flippers may have been enabled by a reduction in twisting loads on proximal limb bones that accompanied swimming in rowing ancestors, facilitating a shift from tubular to flattened limbs. Moreover, the control of flapping movements appears related primarily to shifts in the activity of a single forelimb muscle, the deltoid. Despite some performance advantages, flapping may entail a locomotor cost in terms of decreased locomotor stability. However, other morphological specializations among rowing species may enhance swimming stability. For example, among highly aquatic pleurodiran turtles, fusion of the pelvis to the shell appears to dramatically reduce motions of the pelvis compared to freshwater cryptodiran species. This could contribute to advantageous increases in aquatic stability among predominantly aquatic pleurodires. Thus, even within the potential constraints of a body plan in which the body is encased by a shell, turtles exhibit diverse locomotor capacities that have enabled diversification into a wide range of aquatic habitats. © The Author 2016. Published

The hippocampus and appetitive Pavlovian conditioning: effects of excitotoxic hippocampal lesions on conditioned locomotor activity and autoshaping.

Science.gov (United States)

Ito, Rutsuko; Everitt, Barry J; Robbins, Trevor W

2005-01-01

The hippocampus (HPC) is known to be critically involved in the formation of associations between contextual/spatial stimuli and behaviorally significant events, playing a pivotal role in learning and memory. However, increasing evidence indicates that the HPC is also essential for more basic motivational processes. The amygdala, by contrast, is important for learning about the motivational significance of discrete cues. This study investigated the effects of excitotoxic lesions of the rat HPC and the basolateral amygdala (BLA) on the acquisition of a number of appetitive behaviors known to be dependent on the formation of Pavlovian associations between a reward (food) and discrete stimuli or contexts: (1) conditioned/anticipatory locomotor activity to food delivered in a specific context and (2) autoshaping, where rats learn to show conditioned discriminated approach to a discrete visual CS+. While BLA lesions had minimal effects on conditioned locomotor activity, hippocampal lesions facilitated the development of both conditioned activity to food and autoshaping behavior, suggesting that hippocampal lesions may have increased the incentive motivational properties of food and associated conditioned stimuli, consistent with the hypothesis that the HPC is involved in inhibitory processes in appetitive conditioning. (c) 2005 Wiley-Liss, Inc.

Tamoxifen and estradiol improved locomotor function and increased spared tissue in rats after spinal cord injury: their antioxidant effect and role of estrogen receptor alpha.

Science.gov (United States)

Mosquera, Laurivette; Colón, Jennifer M; Santiago, José M; Torrado, Aranza I; Meléndez, Margarita; Segarra, Annabell C; Rodríguez-Orengo, José F; Miranda, Jorge D

2014-05-02

17β-Estradiol is a multi-active steroid that imparts neuroprotection via diverse mechanisms of action. However, its role as a neuroprotective agent after spinal cord injury (SCI), or the involvement of the estrogen receptor-alpha (ER-α) in locomotor recovery, is still a subject of much debate. In this study, we evaluated the effects of estradiol and of Tamoxifen (an estrogen receptor mixed agonist/antagonist) on locomotor recovery following SCI. To control estradiol cyclical variability, ovariectomized female rats received empty or estradiol filled implants, prior to a moderate contusion to the spinal cord. Estradiol improved locomotor function at 7, 14, 21, and 28 days post injury (DPI), when compared to control groups (measured with the BBB open field test). This effect was ER-α mediated, because functional recovery was blocked with an ER-α antagonist. We also observed that ER-α was up-regulated after SCI. Long-term treatment (28 DPI) with estradiol and Tamoxifen reduced the extent of the lesion cavity, an effect also mediated by ER-α. The antioxidant effects of estradiol were seen acutely at 2 DPI but not at 28 DPI, and this acute effect was not receptor mediated. Rats treated with Tamoxifen recovered some locomotor activity at 21 and 28 DPI, which could be related to the antioxidant protection seen at these time points. These results show that estradiol improves functional outcome, and these protective effects are mediated by the ER-α dependent and independent-mechanisms. Tamoxifen׳s effects during late stages of SCI support the use of this drug as a long-term alternative treatment for this condition. Copyright © 2014 Elsevier B.V. All rights reserved.

Individual differences in object permanence performance at 8 months: locomotor experience and brain electrical activity.

Science.gov (United States)

Bell, M A; Fox, N A

1997-12-01

This work was designed to investigate individual differences in hands-and-knees crawling and frontal brain electrical activity with respect to object permanence performance in 76 eight-month-old infants. Four groups of infants (one prelocomotor and 3 with varying lengths of hands-and-knees crawling experience) were tested on an object permanence scale in a research design similar to that used by Kermoian and Campos (1988). In addition, baseline EEG was recorded and used as an indicator of brain development, as in the Bell and Fox (1992) longitudinal study. Individual differences in frontal and occipital EEG power and in locomotor experience were associated with performance on the object permanence task. Infants successful at A-not-B exhibited greater frontal EEG power and greater occipital EEG power than unsuccessful infants. In contrast to Kermoian and Campos (1988), who noted that long-term crawling experience was associated with higher performance on an object permanence scale, infants in this study with any amount of hands and knees crawling experience performed at a higher level on the object permanence scale than prelocomotor infants. There was no interaction among brain electrical activity, locomotor experience, and object permanence performance. These data highlight the value of electrophysiological research and the need for a brain-behavior model of object permanence performance that incorporates both electrophysiological and behavioral factors.

Circadian locomotor rhythms in the cricket, Gryllodes sigillatus. II. Interactions between bilaterally paired circadian pacemakers.

Science.gov (United States)

Ushirogawa, H; Abe, Y; Tomioka, K

1997-10-01

The optic lobe is essential for circadian locomotor rhythms in the cricket, Gryllodes sigillatus. We examined potential interactions between the bilaterally paired optic lobes in circadian rhythm generation. When one optic lobe was removed, the free-running period of the locomotor rhythm slightly but significantly lengthened. When exposed to light-dark cycles (LD) with 26 hr period, intact and sham operated animals were clearly entrained to the light cycle, but a large number of animals receiving unilateral optic nerve severance showed rhythm dissociation. In the dissociation, two rhythmic components appeared; one was readily entrained to the given LD and the other free-ran with a period shorter than 24 hr, and activity was expressed only when they were inphase. The period of the free-running component was significantly longer than that of the animals with a single blinded pacemaker kept in LD13:13, suggesting that the pacemaker on the intact side had some influence on the blinded pacemaker even in the dissociated state. The ratio of animals with rhythm dissociation was greater with the lower light intensity of the LD. The results suggest that the bilaterally distributed pacemakers are only weakly coupled to one another but strongly suppress the activity driven by the partner pacemaker during their subjective day. The strong suppression of activity would be advantageous to keep a stable nocturnality for this cricket living indoors.

“On the Fence” versus “All in”: Insights from Turtles for the Evolution of Aquatic Locomotor Specializations and Habitat Transitions in Tetrapod Vertebrates

Science.gov (United States)

Blob, Richard W.; Mayerl, Christopher J.; Rivera, Angela R. V.; Rivera, Gabriel; Young, Vanessa K. H.

2016-01-01

Though ultimately descended from terrestrial amniotes, turtles have deep roots as an aquatic lineage and are quite diverse in the extent of their aquatic specializations. Many taxa can be viewed as “on the fence” between aquatic and terrestrial realms, whereas others have independently hyperspecialized and moved “all in” to aquatic habitats. Such differences in specialization are reflected strongly in the locomotor system. We have conducted several studies to evaluate the performance consequences of such variation in design, as well as the mechanisms through which specialization for aquatic locomotion is facilitated in turtles. One path to aquatic hyperspecialization has involved the evolutionary transformation of the forelimbs from rowing, tubular limbs with distal paddles into flapping, flattened flippers, as in sea turtles. Prior to the advent of any hydrodynamic advantages, the evolution of such flippers may have been enabled by a reduction in twisting loads on proximal limb bones that accompanied swimming in rowing ancestors, facilitating a shift from tubular to flattened limbs. Moreover, the control of flapping movements appears related primarily to shifts in the activity of a single forelimb muscle, the deltoid. Despite some performance advantages, flapping may entail a locomotor cost in terms of decreased locomotor stability. However, other morphological specializations among rowing species may enhance swimming stability. For example, among highly aquatic pleurodiran turtles, fusion of the pelvis to the shell appears to dramatically reduce motions of the pelvis compared to freshwater cryptodiran species. This could contribute to advantageous increases in aquatic stability among predominantly aquatic pleurodires. Thus, even within the potential constraints of a body plan in which the body is encased by a shell, turtles exhibit diverse locomotor capacities that have enabled diversification into a wide range of aquatic habitats. PMID:27940619

Locomotor Sensory Organization Test: How Sensory Conflict Affects the Temporal Structure of Sway Variability During Gait.

Science.gov (United States)

Chien, Jung Hung; Mukherjee, Mukul; Siu, Ka-Chun; Stergiou, Nicholas

2016-05-01

When maintaining postural stability temporally under increased sensory conflict, a more rigid response is used where the available degrees of freedom are essentially frozen. The current study investigated if such a strategy is also utilized during more dynamic situations of postural control as is the case with walking. This study attempted to answer this question by using the Locomotor Sensory Organization Test (LSOT). This apparatus incorporates SOT inspired perturbations of the visual and the somatosensory system. Ten healthy young adults performed the six conditions of the traditional SOT and the corresponding six conditions on the LSOT. The temporal structure of sway variability was evaluated from all conditions. The results showed that in the anterior posterior direction somatosensory input is crucial for postural control for both walking and standing; visual input also had an effect but was not as prominent as the somatosensory input. In the medial lateral direction and with respect to walking, visual input has a much larger effect than somatosensory input. This is possibly due to the added contributions by peripheral vision during walking; in standing such contributions may not be as significant for postural control. In sum, as sensory conflict increases more rigid and regular sway patterns are found during standing confirming the previous results presented in the literature, however the opposite was the case with walking where more exploratory and adaptive movement patterns are present.

NWChem Meeting on Science Driven Petascale Computing and Capability Development at EMSL

Energy Technology Data Exchange (ETDEWEB)

De Jong, Wibe A.

2007-02-19

On January 25, and 26, 2007, an NWChem meeting was held that was attended by 65 scientists from 29 institutions including 22 universities and 5 national laboratories. The goals of the meeting were to look at major scientific challenges that could be addressed by computational modeling in environmental molecular sciences, and to identify the associated capability development needs. In addition, insights were sought into petascale computing developments in computational chemistry. During the meeting common themes were identified that will drive the need for the development of new or improved capabilities in NWChem. Crucial areas of development that the developer's team will be focusing on are (1) modeling of dynamics and kinetics in chemical transformations, (2) modeling of chemistry at interfaces and in the condensed phase, and (3) spanning longer time scales in biological processes modeled with molecular dynamics. Various computational chemistry methodologies were discussed during the meeting, which will provide the basis for the capability developments in the near or long term future of NWChem.

Improvements in bladder, bowel and sexual outcomes following task-specific locomotor training in human spinal cord injury

Science.gov (United States)

Williams, Carolyn S.; Montgomery, Lynnette R.; Willhite, Andrea M.; Angeli, Claudia A.; Harkema, Susan J.

2018-01-01

Objective Locomotor training (LT) as a therapeutic intervention following spinal cord injury (SCI) is an effective rehabilitation strategy for improving motor outcomes, but its impact on non-locomotor functions is unknown. Given recent results of our labs’ pre-clinical animal SCI LT studies and existing overlap of lumbosacral spinal circuitries controlling pelvic-visceral and locomotor functions, we addressed whether LT can improve bladder, bowel and sexual function in humans at chronic SCI time-points (> two years post-injury). Study design Prospective cohort study; pilot trial with small sample size. Methods Eight SCI research participants who were undergoing 80 daily one-hour sessions of LT on a treadmill using body-weight support, or one-hour of LT and stand training on alternate days, as part of another research study conducted at the Kentucky Spinal Cord Injury Research Center, University of Louisville, were enrolled in this pilot trial. Urodynamic assessments were performed and International Data Set questionnaire forms completed for bladder, bowel and sexual functions at pre-and post-training time points. Four usual care (non-trained; regular at-home routine) research participants were also enrolled in this study and had the same assessments collected twice, at least 3 months apart. Results Filling cystometry documented significant increases in bladder capacity, voiding efficiency and detrusor contraction time as well as significant decreases in voiding pressure post-training relative to baseline. Questionnaires revealed a decrease in the frequency of nocturia and urinary incontinence for several research participants as well as a significant decrease in time required for defecation and a significant increase in sexual desire post-training. No significant differences were found for usual care research participants. Conclusions These results suggest that an appropriate level of sensory information provided to the spinal cord, generated through task

Capability Building and Learning: An Emergent Behavior Approach

Directory of Open Access Journals (Sweden)

Andreu Rafael

2014-12-01

Full Text Available Economics-based models of firms typically overlook management acts and capability development. We propose a model that analyzes the aggregate behavior of a population of firms resulting from both specific management decisions and learning processes, that induce changes in companies’ capabilities. Decisions are made under imperfect information and bounded rationality, and managers may sacrifice short-term performance in exchange for qualitative outcomes that affect their firm’s future potential. The proposed model provides a structured setting in which these issues -often discussed only informally- can be systematically analyzed through simulation, producing a variety of hard-to-anticipate emergent behaviors. Economic performance is quite sensitive to managers’ estimates of their firms’ capabilities, and companies willing to sacrifice short-run results for future potential appear to be more stable than the rest. Also, bounded rationality can produce chaotic dynamics reminiscent of real life situations.

ORGANISATIONAL CAPABILITIES, COMPETITIVE ADVANTAGE AND PERFORMANCE IN SUPPORTING INDUSTRIES IN VIETNAM

Directory of Open Access Journals (Sweden)

Nham Phong Tuan

2010-01-01

Full Text Available This paper focuses on applying the resource-based view (RBV of firms to explain performance in supporting industries in Vietnam. Specifically, we based our research on the comprehensive framework of RBV and reviewed previous empirical researches before deciding on adopting a dynamic capabilities approach to test relationships among organisational capabilities, competitive advantage and performance. A multivariate analysis of survey responses of 102 firms belonging to supporting industries in Vietnam indicates that the organisational capabilities are related to the competitive advantage, that the competitive advantage is related to performance, and that the competitive advantage mediates the relationship between organizational capabilities and performance. These findings have considerable implications for academics as well as practitioners. Finally, this study also provides directions for future research.

Relationships between Lower Limb Muscle Strength and Locomotor Capacity in Children and Adolescents with Cerebral Palsy Who Walk Independently

Science.gov (United States)

Ferland, Chantale; Lepage, Celine; Moffet, Helene; Maltais, Desiree B.

2012-01-01

This study aimed to quantify relationships between lower limb muscle strength and locomotor capacity for children and adolescents with cerebral palsy (CP) to identify key muscle groups for strength training. Fifty 6- to 16-year-olds with CP (Gross Motor Function Classification System level I or II) participated. Isometric muscle strength of hip…

Comparative anatomy of the arm muscles of the Japanese monkey (Macaca fuscata) with some comments on locomotor mechanics and behavior.