Identifying the mechanisms underpinning recognition of structured sequences of action

© 2012 The Experimental Psychology SocietyWe present three experiments to identify the specific information sources that skilled participants use to make recognition judgements when presented with dynamic, structured stimuli. A group of less skilled participants acted as controls. In all experiments, participants were presented with filmed stimuli containing structured action sequences. In a subsequent recognition phase, participants were presented with new and previously seen stimuli and were required to make judgements as to whether or not each sequence had been presented earlier (or were edited versions of earlier sequences). In Experiment 1, skilled participants demonstrated superior sensitivity in recognition when viewing dynamic clips compared with static images and clips where the frames were presented in a nonsequential, randomized manner, implicating the importance of motion information when identifying familiar or unfamiliar sequences. In Experiment 2, we presented normal and mirror-reversed sequences in order to distort access to absolute motion information. Skilled participants demonstrated superior recognition sensitivity, but no significant differences were observed across viewing conditions, leading to the suggestion that skilled participants are more likely to extract relative rather than absolute motion when making such judgements. In Experiment 3, we manipulated relative motion information by occluding several display features for the duration of each film sequence. A significant decrement in performance was reported when centrally located features were occluded compared to those located in more peripheral positions. Findings indicate that skilled participants are particularly sensitive to relative motion information when attempting to identify familiarity in dynamic, visual displays involving interaction between numerous features

REAÇÃO LEUCEMÓIDE ASSOCIADA À SARCOMA INDIFERENCIADO EM INTESTINO DELGADO DE CÃO

An eleven-year-old Poodle was carried to the Veterinary Hospital of the Universidade Federal do Paraná (UFPR) with a six-month history of weight loss and hiporexia. On physical examination the dog shows afebrile and had pale mucous membranes. Routine haematological examination revealed anemia, leucocytosis, marked mature neutrophilia left shift (101,200 cell/µL; 87,032 segmented/µL; 4,048 band//µL). Examination of bone marrow to the smears confirmed a marked leukemoid response, indicating myeloid hyperplasia without evidence of leukemia. Imagery showed a presence of a 3,43 cm diameter mass in the piloro-duodenal segment. The mass was surgically removed. Histologically, it revealed a malignancy suggestive of sarcoma. Post-operatively, the dogs appetite improved. On re- evaluation, routine haematology revealed a reduction in the mature and band neutrophils count (6,348 neutrophils/µL; 0 band/µL). This report describes a case of paraneoplastic leukemoid reaction with resolution of the abnormality following removal of the neoplasm.Um cão da raça Poodle, de 11 anos de idade foi encaminhado ao Hospital Veterinário da Universidade Federal do Paraná (UFPR), com histórico de hiporexia e emagrecimento há seis meses. No exame físico constatou-se caquexia, mucosas hipocoradas e ausência de febre. No hemograma observou-se anemia, leucocitose, neutrofilia extrema e desvio nuclear dos neutrófilos à esquerda (101.200 leucócitos/µL; 87.032 segmentados/µL; 4.048 bastonetes/µL). No exame da medula óssea observou-se hiperplasia mielóide sem evidências de leucemia, confirmando a ocorrência de reação leucemóide. A ultra-sonografia abdominal identificou estrutura de 3,43 cm em alças intestinais, sugestiva de neoplasia mural de segmento piloro-duodenal. Realizou-se a exérese cirúrgica. O tumor foi identificado como neoplasia maligna de origem mesenquimal no exame histopatológico. No pós-operatório observou-se apetite normal do cão e a resolução das anormalidades hematológicas (6.348 neutrófilos/µL; 0 bastonetes/µL). O presente trabalho descreve um caso de reação leucemóide paraneoplásica com resolução das anormalidades após a remoção da neoplasia

Neutrino Propagation in a Strongly Magnetized Medium

We derive general expressions at the one-loop level for the coefficients of the covariant structure of the neutrino self-energy in the presence of a constant magnetic field. The neutrino energy spectrum and index of refraction are obtained for neutral and charged media in the strong-field limit ($M_{W}\gg \sqrt{B}\gg m_{e},T,\mu ,| \mathbf{p}|$) using the lowest Landau level approximation. The results found within the lowest Landau level approximation are numerically validated, summing in all Landau levels, for strong $B\gg T^{2}$ and weakly-strong $B \gtrsim T^{2}$ fields. The neutrino energy in leading order of the Fermi coupling constant is expressed as the sum of three terms: a kinetic-energy term, a term of interaction between the magnetic field and an induced neutrino magnetic moment, and a rest-energy term. The leading radiative correction to the kinetic-energy term depends linearly on the magnetic field strength and is independent of the chemical potential. The other two terms are only present in a charged medium. For strong and weakly-strong fields, it is found that the field-dependent correction to the neutrino energy in a neutral medium is much larger than the thermal one. Possible applications to cosmology and astrophysics are considered.Comment: 23 pages, 4 figures. Corrected misprints in reference

Magnetic Catalysis: A Review

We give an overview of the magnetic catalysis phenomenon. In the framework of quantum field theory, magnetic catalysis is broadly defined as an enhancement of dynamical symmetry breaking by an external magnetic field. We start from a brief discussion of spontaneous symmetry breaking and the role of a magnetic field in its a dynamics. This is followed by a detailed presentation of the essential features of the phenomenon. In particular, we emphasize that the dimensional reduction plays a profound role in the pairing dynamics in a magnetic field. Using the general nature of underlying physics and its robustness with respect to interaction types and model content, we argue that magnetic catalysis is a universal and model-independent phenomenon. In support of this claim, we show how magnetic catalysis is realized in various models with short-range and long-range interactions. We argue that the general nature of the phenomenon implies a wide range of potential applications: from certain types of solid state systems to models in cosmology, particle and nuclear physics. We finish the review with general remarks about magnetic catalysis and an outlook for future research.Comment: 37 pages, to appear in Lect. Notes Phys. "Strongly interacting matter in magnetic fields" (Springer), edited by D. Kharzeev, K. Landsteiner, A. Schmitt, H.-U. Yee. Version 2: references adde

New Strong-Field QED Effects at ELI: Nonperturbative Vacuum Pair Production

Since the work of Sauter, and Heisenberg, Euler and K\"ockel, it has been understood that vacuum polarization effects in quantum electrodynamics (QED) predict remarkable new phenomena such as light-light scattering and pair production from vacuum. However, these fundamental effects are difficult to probe experimentally because they are very weak, and they are difficult to analyze theoretically because they are highly nonlinear and/or nonperturbative. The Extreme Light Infrastructure (ELI) project offers the possibility of a new window into this largely unexplored world. I review these ideas, along with some new results, explaining why quantum field theorists are so interested in this rapidly developing field of laser science. I concentrate on the theoretical tools that have been developed to analyze nonperturbative vacuum pair production.Comment: 20 pages, 9 figures; Key Lecture at the ELI Workshop and School on "Fundamental Physics with Ultra-High Fields", 29 Sept - 2 Oct. 2008, Frauenworth Monastery, Germany; v2: refs updated, English translations of reviews of Nikishov and Ritu