Nonlocal Games and Quantum Permutation Groups

We present a strong connection between quantum information and quantum permutation groups. Specifically, we define a notion of quantum isomorphisms of graphs based on quantum automorphisms from the theory of quantum groups, and then show that this is equivalent to the previously defined notion of quantum isomorphism corresponding to perfect quantum strategies to the isomorphism game. Moreover, we show that two connected graphs $X$ and $Y$ are quantum isomorphic if and only if there exists $x \in V(X)$ and $y \in V(Y)$ that are in the same orbit of the quantum automorphism group of the disjoint union of $X$ and $Y$. This connection links quantum groups to the more concrete notion of nonlocal games and physically observable quantum behaviours. We exploit this link by using ideas and results from quantum information in order to prove new results about quantum automorphism groups, and about quantum permutation groups more generally. In particular, we show that asymptotically almost surely all graphs have trivial quantum automorphism group. Furthermore, we use examples of quantum isomorphic graphs from previous work to construct an infinite family of graphs which are quantum vertex transitive but fail to be vertex transitive, answering a question from the quantum group literature. Our main tool for proving these results is the introduction of orbits and orbitals (orbits on ordered pairs) of quantum permutation groups. We show that the orbitals of a quantum permutation group form a coherent configuration/algebra, a notion from the field of algebraic graph theory. We then prove that the elements of this quantum orbital algebra are exactly the matrices that commute with the magic unitary defining the quantum group. We furthermore show that quantum isomorphic graphs admit an isomorphism of their quantum orbital algebras which maps the adjacency matrix of one graph to that of the other.Comment: 39 page

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Experimental muscle hyperalgesia modulates sensorimotor cortical excitability, which is partially altered by unaccustomed exercise

Impaired corticomotor function is reported in patients with lateral epicondylalgia, but the causal link to pain or musculotendinous overloading is unclear. In this study, sensorimotor cortical changes were investigated using a model of persistent pain combined with an overloading condition. In 24 healthy subjects, the effect of nerve growth factor (NGF)-induced pain, combined with delayed-onset muscle soreness (DOMS), was examined on pain perception, pressure pain sensitivity, maximal force, and sensorimotor cortical excitability. Two groups (NGF alone and NGF + DOMS) received injections of NGF into the extensor carpi radialis brevis (ECRB) muscle at day 0, day 2, and day 4. At day 4, the NGF + DOMS group undertook wrist eccentric exercise to induce DOMS in the ECRB muscle. Muscle soreness scores, pressure pain thresholds over the ECRB muscle, maximal grip force, transcranial magnetic stimulation mapping of the cortical ECRB muscle representation, and somatosensory-evoked potentials from radial nerve stimulation were recorded at day 0, day 4, and day 6. Compared with day 0, day 4 showed in both groups: (1) increased muscle soreness (P < 0.01); (2) reduced pressure pain thresholds (P < 0.01); (3) increased motor map volume (P < 0.01); and (4) decreased frontal N30 somatosensory-evoked potential. At day 6, compared with day 4, only the DOMS + NGF group showed: (1) increased muscle soreness score (P < 0.01); (2) decreased grip force (P < 0.01); and (3) decreased motor map volume (P < 0.05). The NGF group did not show any difference on the remaining outcomes from day 4 to day 6. These data suggest that sustained muscle pain modulates sensorimotor cortical excitability and that exercise-induced DOMS alters pain-related corticomotor adaptation

On Civil Education: Beginning A Dialogue

In his recent book, The End of Work, economist and political activist Jeremy Rifkin describes the dramatic shift the global economy is undergoing as we enter the next century. Rifkin documents the move from a mass worker economy to a high technology global economy that thrives on the innovations of labor-saving technology and corporate downsizing. In the agricultural, manufacturing, and service sectors, he writes, machines are quickly replacing human labor and promise an economy of near automated production by the mid-decades of the twenty-first century. Rifkin argues that government is also offering fewer employment opportunities, and that the rising high-tech industries are likely to increase the job pool only for a relatively small number of elite workers (1995)

High frequency repetitive transcranial magnetic stimulation to the left dorsolateral prefrontal cortex modulates sensorimotor cortex function in the transition to sustained muscle pain

Based on reciprocal connections between the dorsolateral prefrontal cortex (DLPFC) and basal-ganglia regions associated with sensorimotor cortical excitability, it was hypothesized that repetitive transcranial magnetic stimulation (rTMS) of the left DLPFC would modulate sensorimotor cortical excitability induced by muscle pain. Muscle pain was provoked by injections of nerve growth factor (end of Day-0 and Day-2) into the right extensor carpi radialis brevis (ECRB) muscle in two groups of 15 healthy participants receiving 5 daily sessions (Day-0 to Day-4) of active or sham rTMS. Muscle pain scores and pressure pain thresholds (PPTs) were collected (Day-0, Day-3, Day-5). Assessment of motor cortical excitability using TMS (mapping cortical ECRB muscle representation) and somatosensory evoked potentials (SEPs) from electrical stimulation of the right radial nerve were recorded at Day-0 and Day-5. At Day-0 versus Day-5, the sham compared to active group showed: Higher muscle pain scores and reduced PPTs (P < 0.04); decreased frontal N30 SEP (P < 0.01); increased TMS map volume (P < 0.03). These results indicate that muscle pain exerts modulatory effects on the sensorimotor cortical excitability and left DLPFC rTMS has analgesic effects and modulates pain-induced sensorimotor cortical adaptations. These findings suggest an important role of prefrontal to basal-ganglia function in sensorimotor cortical excitability and pain processing

Spider Web Graphs

Recent results from Chih-Scull show that the ×-homotopy relation on finite graphs can be expressed via a sequence of “spider moves” which shift a single vertex at a time. In this paper we study a “spider web graph” which encodes exactly these spider moves between graph homomorphisms. We show how composition of graph homomorphisms relate to the spider web, study the components of spider webs for bipartite and tree graphs, andfinish by giving an explicit description of the spider web for homomorphisms from a bipartite graph to a star graph

Materia optativa a distancia "Búsqueda, acceso y manejo de información científica" en la Biblioteca Central de la Facultad de Agronomía de la UBA : qué, cómo y cuándo

Describes the process that resulted in the development of an elective course "Search, access and management of scientific information" dictated by the Central Library of the School of Agronomy of the University of Buenos Aires. The information literacy program maintained by the Library for 12 years trained almost 4800 students and teachers. The program began as a "Training Program in the development of skills to access agronomic information" in 2006, based on the standards of the Association of College and Research Libraries (ACRL) of the American Library Association. (ACRL, 2008). This standard, replaced in 2016 by the "Framework for information literacy for higher education" (ACRL, 2016), has opened a new panorama in information literacy. In 2013, began a period of evaluation of the program, which has taken in consideration changes in the curricula of the careers that are offered in the School of Agriculture, the advances produced in distance learning, and new needs raised by students and teachers. The development of a distance learning optional course given by library staff, was the result of this process. The course has been offered for two years. The contents, the applied methodology and the digital educational materials developed with the support of the Distance Education Center of the School are presented here

Materia optativa a distancia "Búsqueda, acceso y manejo de información científica" en la Biblioteca Central de la Facultad de Agronomía de la UBA : qué, cómo y cuándo

Describes the process that resulted in the development of an elective course "Search, access and management of scientific information" dictated by the Central Library of the School of Agronomy of the University of Buenos Aires. The information literacy program maintained by the Library for 12 years trained almost 4800 students and teachers. The program began as a "Training Program in the development of skills to access agronomic information" in 2006, based on the standards of the Association of College and Research Libraries (ACRL) of the American Library Association. (ACRL, 2008). This standard, replaced in 2016 by the "Framework for information literacy for higher education" (ACRL, 2016), has opened a new panorama in information literacy. In 2013, began a period of evaluation of the program, which has taken in consideration changes in the curricula of the careers that are offered in the School of Agriculture, the advances produced in distance learning, and new needs raised by students and teachers. The development of a distance learning optional course given by library staff, was the result of this process. The course has been offered for two years. The contents, the applied methodology and the digital educational materials developed with the support of the Distance Education Center of the School are presented here