Stochastic Imitation in Finite Games

In this paper we model an evolutionary process with perpetual random shocks where individual behavior is determined by imitation. Every period an agent is randomly chosen from each of n finite populations to play a game. Each agent observes a sample of population-specific past strategy and payoff realizations. She thereafter imitates by choosing the strategy with highest average payoff in the sample. Occasionally the agents also experiment or make mistakes and choose a strategy at random. For finite n-player games we prove that in the limit, as the probability of experimentation tends to zero, only strategy-tuples in minimal sets closed under the better-reply graph will be played with positive probability. If the strategy-tuples in one such minimal set have strictly higher payoffs than all outside strategy-tuples, then the strategy-tuples in this set will be played with probability one in the limit, provided the minimal set is a product set. We also show that in 2x2 games the convergence in our model is faster than in other known models.Evolutionary game theory; bounded rationality; imitation; Markov chain; stochastic stability; better replies; Pareto dominance

Individual Learning in Construction Projects: Professions and their Approaches

New materials, use of sophisticatedtechnologies and increased customerdemands, in combination with growingcompetition among construction companies,have led to a high degree of specialization. Forsuccessful integration of the differentprofessional specialists, there is a need forshared learning between project co-workers.Based on twenty eight interviews in sixdifferent Swedish construction projects, thispaper illustrates strategies for individual andshared learning, among different actors andacross various organizational boundaries. Theresults indicate that personal networks are themost common source of learning for allprofessions. While clients, architects, anddesigners also engage in reading andattending courses, site managers and workersare less engaged in these activities.Experimenting and organizing for learningappear to be underutilized strategies by allprofessions. This leads to the conclusion thatattempts to increase learning have to addressthe differences in learning behaviors of thevarious groups. Further, focus onexperimenting and organizing for learning is apossibility to change the learning behaviorfrom learning as a consequence of problemsto learning for future improvement

Individual Learning in Construction Projects: Professions and their Approaches

New materials, use of sophisticated technologies and increased customer demands, in combination with growing competition among construction companies, have led to a high organizational boundaries. The results indicate that personal networks are the most common source of learning for all professions. While clients, architects, and designers also engage in reading and attending courses, site managers and workers are less engaged in these activities. Experimenting and organizing for learning appear to be underutilized strategies by all professions. This leads to the conclusion that attempts to increase learning have to address the differences in learning behaviours of the various groups. Further, focus on experimenting and organizing for learning is a possibility to change the learning behaviour from learning as a consequence of problems to learning for future improvement.degree of specialization. For successful integration of the different professional specialists, there is a need for shared learning between project co-workers. Based on twenty eight interviews in six different Swedish construction projects, this paper illustrates strategies for individual and shared learning, among different actors and across variou

Making Manifest : Grounding Islam

The Caveat For many reasons, names have had to be concealed within this document. The events depicted are real and the discussions true. This is an attempt to legitimize the informal, seemingly mundane and sometimes personal: the author’s experiences bringing a folly to the physical, while trespassing into a new world: Islam. This thesis documents a series of interventions at different scales within that world. There is a book, the chair, and the city of Makkah. The events themselves are superimposed onto the traditional language, or professional conventions, used to justify them. Here, they are relegated to the margins of each page. This is akin to how some of the first books were produced, by students in the confines of dark cloisters or hot desert temples, struggling to maintain historical integrity while fighting the natural tendencies of youth. Their master’s voices always looking over the gutter from the opposite page. The sketches for a new Makkah and a monumental demonstration in Canada unfold in parallel to a body of formal research. Together, as seemingly independently as they are, they paint the portrait of an Islam, while building a personality between the lines. That being said: there isn’t a correct way to read it

Probing Pseudogap by Josephson Tunneling

We propose here an experiment aimed to determine whether there are superconducting pairing fluctuations in the pseudogap regime of the high-$T_c$ materials. In the experimental setup, two samples above $T_c$ are brought into contact at a single point and the differential AC conductivity in the presence of a constant applied bias voltage between the samples, $V$, should be measured. We argue the the pairing fluctuations will produce randomly fluctuating Josephson current with zero mean, however the current-current correlator will have a characteristic frequency given by Josephson frequency $\omega_J = 2 e V /\hbar$. We predict that the differential AC conductivity should have a peak at the Josephson frequency with the width determined by the phase fluctuations time.Comment: 4 pages, 2 eps figure

Cooper Pair Shape in Normal-metal/Superconductor Junctions

In s-wave superconductors the Cooper pair wave function is isotropic in momentum space. This property may also be expected for Cooper pairs entering a normal metal from a superconductor due to the proximity effect. We show, however, that such a deduction is incorrect and the pairing function in a normal metal is surprisingly anisotropic because of quasiparticle interference. We calculate angle resolved quasiparticle density of states in NS bilayers which reflects such anisotropic shape of the pairing function. We also propose a magneto-tunneling spectroscopy experiment which could confirm our predictions

Use of a Single Hybrid Imaging Agent for Integration of Target Validation with In Vivo and Ex Vivo Imaging of Mouse Tumor Lesions Resembling Human DCIS

Screening of biomarker expression levels in tumor biopsy samples not only provides an assessment of prognostic and predictive factors, but may also be used for selection of biomarker-specific imaging strategies. To assess the feasibility of using a biopsy specimen for a personalized selection of an imaging agent, the chemokine receptor 4 (CXCR4) was used as a reference biomarker. Methods: A hybrid CXCR4 targeting peptide (MSAP-Ac-TZ14011) containing a fluorescent dye and a chelate for radioactive labeling was used to directly compare initial flow cytometry–based target validation in fresh tumor tissue to $in$ $vivo$ single photon emission computed tomography (SPECT) imaging and $in$ $vivo$ and $ex$ $vivo$ fluorescence imaging. Results: Flow cytometric analysis of mouse tumor derived cell suspensions enabled discrimination between 4T1 control tumor lesions (with low levels of CXCR4 expression) and CXCR4 positive early, intermediate and late stage MIN-O lesions based on their CXCR4 expression levels; CXCR4$^{basal}$, CXCR4$^+$ and CXCR4$^{++}$ cell populations could be accurately discriminated. Mean fluorescent intensity ratios between expression in MIN-O and 4T1 tissue found with flow cytometry were comparable to ratios obtained with in vivo SPECT/CT and fluorescence imaging, ex vivo fluorescence evaluation and standard immunohistochemistry. Conclusion: The hybrid nature of a targeting imaging agent like MSAP-Ac-TZ14011 enables integration of target selection, in vivo imaging and ex vivo validation using a single agent. The use of biopsy tissue for biomarker screening can readily be expanded to other targeting hybrid imaging agents and can possibly help increase the clinical applicability of tumor-specific imaging approaches

The role of intrinsic muscle mechanics in the neuromuscular control of stable running in the guinea fowl

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66308/1/jphysiol.2009.171017.pd

What can isolated skeletal muscle experiments tell us about the effects of caffeine on exercise performance?

Caffeine is an increasingly popular nutritional supplement due to the legal, significant improvements in sporting performance that it has been documented to elicit, with minimal side effects. Therefore, the effects of caffeine on human performance continue to be a popular area of research as we strive to improve our understanding of this drug and make more precise recommendations for its use in sport. Although variations in exercise intensity seems to affect its ergogenic benefits, it is largely thought that caffeine can induce significant improvements in endurance, power and strength-based activities. There are a number of limitations to testing caffeine-induced effects on human performance that can be better controlled when investigating its effects on isolated muscles under in vitro conditions. The hydrophobic nature of caffeine results in a post-digestion distribution to all tissues of the body making it difficult to accurately quantify its key mechanism of action. This review considers the contribution of evidence from isolated muscle studies to our understating of the direct effects of caffeine on muscle during human performance. The body of in vitro evidence presented suggests that caffeine can directly potentiate skeletal muscle force, work and power, which may be important contributors to the performance-enhancing effects seen in humans