Spatial and Timing Regulation of Upper-Limb Movements in Rhythmic Tasks

Rhythmic movement is vital to humans and a foundation of such activities as locomotion, handwriting, and repetitive tool use. The spatiotemporal regularity characterizing such movements reflects a level of automaticity and coordination that is believed to emerge from mutually inhibitory or other pattern generating neural networks in the central nervous system. Although many studies have provided descriptions of this regularity and have illuminated the types of sensory information that influence rhythmic behavior, an understanding of how the brain uses sensory feedback to regulate rhythmic behavior on a cycle-by-cycle basis has been elusive. This thesis utilizes the model task of paddle juggling, or vertical ball bouncing, to address how three types of feedback---visual, auditory, and haptic---contribute to spatial and temporal regulation of rhythmic upper-limb movements. We use a multi-level approach in accordance with the well-known dictum of Marr and Poggio. The crux of this thesis describes a method and suite of experiments to understand how the brain uses visual, audio, and haptic feedback to regulate spatial or timing regularity, and formulate acycle-by-cycle description of this control: to wit, the nature and algorithms of sensory-feedback guided regulation. Part I motivates our interest in this problem, by discussing the biological ``hardware'' that the nervous system putatively employs in these movements, and reviewing insights from previous studies of paddle juggling that suggest how the ``hardware'' may manifest itself in these behaviors. The central experimental approach of this thesis is to train participants to perform the paddle juggling task with spatiotemporal regularity (in other words, to achieve limit-cycle behavior), and then interrogate how the brain applies regulates closed-loop performance by perturbing task feedback. In Part II, we review the development of a novel hard-real-time virtual-reality juggling simulator that enabled precise spatial and temporal feedback perturbations. We then outline the central experimental approach, in which we perturb spatial feedback of the ball at apex phase (vision), and timing feedback of collision- (audio and haptic) and apex-phase events to understand spatial and timing regulation. Part III describes two experiments that yield the main research findings of this thesis. In Experiment 1, we use a sinusoidal-perturbation-based system identification approach to determine that spatial and timing feedback are used in two dissociable and complementary control processes: spatial error correction and temporal synchronization. In Experiment 2, a combination of sinusoidal and step perturbations is used to establish that these complementary processes obey different dynamics. Namely, spatial correction is a proportional-integral process based on a one-step memory of feedback, while temporal synchronization is a proportional process that is dependent only on the most recent feedback. We close in Part IV with a discussion of how insights and approaches from this thesis can lead to improved rehabilitation approaches and understanding of the physiological basis of rhythmic movement regulation

Book of abstracts of the 10th International Chemical and Biological Engineering Conference: CHEMPOR 2008

This book contains the extended abstracts presented at the 10th International Chemical and Biological Engineering Conference - CHEMPOR 2008, held in Braga, Portugal, over 3 days, from the 4th to the 6th of September, 2008. Previous editions took place in Lisboa (1975, 1889, 1998), Braga (1978), Póvoa de Varzim (1981), Coimbra (1985, 2005), Porto (1993), and Aveiro (2001). The conference was jointly organized by the University of Minho, “Ordem dos Engenheiros”, and the IBB - Institute for Biotechnology and Bioengineering with the usual support of the “Sociedade Portuguesa de Química” and, by the first time, of the “Sociedade Portuguesa de Biotecnologia”. Thirty years elapsed since CHEMPOR was held at the University of Minho, organized by T.R. Bott, D. Allen, A. Bridgwater, J.J.B. Romero, L.J.S. Soares and J.D.R.S. Pinheiro. We are fortunate to have Profs. Bott, Soares and Pinheiro in the Honor Committee of this 10th edition, under the high Patronage of his Excellency the President of the Portuguese Republic, Prof. Aníbal Cavaco Silva. The opening ceremony will confer Prof. Bott with a “Long Term Achievement” award acknowledging the important contribution Prof. Bott brought along more than 30 years to the development of the Chemical Engineering science, to the launch of CHEMPOR series and specially to the University of Minho. Prof. Bott’s inaugural lecture will address the importance of effective energy management in processing operations, particularly in the effectiveness of heat recovery and the associated reduction in greenhouse gas emission from combustion processes. The CHEMPOR series traditionally brings together both young and established researchers and end users to discuss recent developments in different areas of Chemical Engineering. The scope of this edition is broadening out by including the Biological Engineering research. One of the major core areas of the conference program is life quality, due to the importance that Chemical and Biological Engineering plays in this area. “Integration of Life Sciences & Engineering” and “Sustainable Process-Product Development through Green Chemistry” are two of the leading themes with papers addressing such important issues. This is complemented with additional leading themes including “Advancing the Chemical and Biological Engineering Fundamentals”, “Multi-Scale and/or Multi-Disciplinary Approach to Process-Product Innovation”, “Systematic Methods and Tools for Managing the Complexity”, and “Educating Chemical and Biological Engineers for Coming Challenges” which define the extended abstracts arrangements along this book. A total of 516 extended abstracts are included in the book, consisting of 7 invited lecturers, 15 keynote, 105 short oral presentations given in 5 parallel sessions, along with 6 slots for viewing 389 poster presentations. Full papers are jointly included in the companion Proceedings in CD-ROM. All papers have been reviewed and we are grateful to the members of scientific and organizing committees for their evaluations. It was an intensive task since 610 submitted abstracts from 45 countries were received. It has been an honor for us to contribute to setting up CHEMPOR 2008 during almost two years. We wish to thank the authors who have contributed to yield a high scientific standard to the program. We are thankful to the sponsors who have contributed decisively to this event. We also extend our gratefulness to all those who, through their dedicated efforts, have assisted us in this task. On behalf of the Scientific and Organizing Committees we wish you that together with an interesting reading, the scientific program and the social moments organized will be memorable for all.Fundação para a Ciência e a Tecnologia (FCT

Handbook of sociological science : contributions to rigorous sociology

22 of the 26 chapters are Open AccessThe Handbook of Sociological Science offers a refreshing, integrated perspective on research programs and ongoing developments in sociological science. It highlights key shared theoretical and methodological features, thereby contributing to progress and cumulative growth of sociological knowledge. Reflecting ‘unity in diversity’, chapters explore a wide variety of research fields, ranging from cultural capital, migration, social networks, gender inequality, historical sociology and ethnography to the intersection of sociology and the life sciences. Examining basic methodological standards for theory construction and empirical research, the Handbook exemplifies commonalities between research programmes within these fields. The contributors also explore rigorous sociology related to theory construction, empirical research, and methods, including statistical modelling and the integration of theoretical and empirical research. Forward-thinking and original, the Handbook concludes by illustrating the common core of rigorous sociology, how it can contribute to understanding societal problems and to policy making, and how research into sociological science can continue to thrive in the future. Accessible and engaging, this Handbook will be invaluable for scholars and researchers of sociology and sociological theory, research methods in sociology and social policy, and comparative social policy. Exploring new developments and applications, it will also act as a useful reference guide for policy makers. The Handbook will likewise be an important resource for teaching advanced courses and training graduate students.INTRODUCTION 1. Rigorous sociology 2, Werner Raub, Nan Dirk de Graaf, and Klarita Gërxhani PART I RESEARCH PROGRAMS 2. Order from chaos: sociology as a population science 21, Michelle Jackson 3. Analytical sociology 38, Gianluca Manzo 4. Computational approaches in rigorous sociology: agent-based computational, modeling and computational social science 57, Andreas Flache, Michael Mäs, and Marijn A. Keijzer 5. Stochastic network modeling as generative social science 73, Christian E.G. Steglich and Tom A.B. Snijders 6. Rational choice sociology: heuristic potential, applications, and limitations 100, Andreas Diekmann PART II NEW AND ONGOING DEVELOPMENTS IN SELECTED FIELDS 7. Cultural capital and educational inequality: an assessment of the state of the art 121, Mads Meier Jæger 8. Integration in migration societies 135, Frank Kalter 9. Social networks: effects and formation 154, Vincent Buskens, Rense Corten, and Werner Raub 10. Gender inequality, households, and work 176, Eva Jaspers, Tanja van der Lippe, and Marie Evertsson 11. Validation strategies in historical sociology (and beyond) 196, Ivan Ermakoff 12. Rigorous ethnography 215, Federico Varese 13. Evolution, biology, and society 232, Rosemary L. Hopcroft, Joseph Dippong, Hexuan Liu, and Rachel Kail 14. Sociogenomics: theoretical and empirical challenges of integrating molecular genetics into sociological thinking 250, Melinda C. Mills PART III METHODS 15. Causal inference with observational data 272, Richard Breen 16. Longitudinal designs and models for causal inference 287, Markus Gangl 17. Experimental sociology 309, Klarita Gërxhani and Luis Miller PART IV RIGOROUS SOCIOLOGY IN ACTION: SHOWCASES 18. Explaining educational differentials: towards a formal rational action theory 325, Richard Breen and John H. Goldthorpe 19. ‘Explaining educational differentials’ revisited: an evaluation of rigorous theoretical foundations and empirical findings 356, Rolf Becker 20. Structural holes and good ideas 372, Ronald S. Burt 21. Network mechanisms in innovation: borrowing and sparking ideas around structural holes 423, Balazs Vedres 22. Experimental study of inequality and unpredictability in an artificial cultural market 443, Matthew J. Salganik, Peter Sheridan Dodds, and Duncan J. Watts 23. Self-correcting dynamics in social influence processes 446, Arnout van de Rijt PART V FURTHER PERSPECTIVES 24. The climate crisis: what sociology can contribute 475, Dingeman Wiertz and Nan Dirk de Graaf 25. Roots of sociology as a science: some history of ideas 493, Thomas Voss 26. How to increase reproducibility and credibility of sociological research 512, Katrin Auspurg and Josef Brüderl -- Index 52