Psychophysical evidence for a functional hierarchy of motion processing mechanisms

Current models of motion perception typically describe mechanisms that operate locally to extract direction and speed information. To deal with the movement of self or objects with respect to the environment, higher-level receptive fields are presumably assembled from the outputs of such local analyzers. We find that the apparent speed of gratings viewed through four spatial apertures depends on the interaction of motion directions among the apertures, even when the motion within each aperture is identical except for direction. Specifically, local motion consistent with a global pattern of radial motion appears 32% faster than that consistent with translational or rotational motion. The enhancement of speed is not reflected in detection thresholds and persists in spite of instructions to fixate a single local aperture and ignore the global configuration. We also find that a two-dimensional pattern of motion is necessary to elicit the effect and that motion contrast alone does not produce the enhancement. These results implicate at least two serial stages of motion-information processing: a mechanism to code the local direction and speed of motion, followed by a global mechanism that integrates such signals to represent meaningful patterns of movement, depending on the configuration of the local motions.     

A new non-random chromosomal translocation t(3;6)(q27;p21.3) associated with BCL6 rearrangement in two patients with non-Hodgkin's lymphoma

We describe two cases of non-Hodgkin's lymphoma associated with t(3;6)(q27;p21.3) and BCL6 rearrangement. The first case was in a 78-year old woman, whose performance status (PS) was 1, the serum lactate dehydrogenase (LDH) level was elevated, and the Ann Arbor stage was IIIA with no extra nodal lymphomatous site. The pathological diagnosis from a biopsy of the inguinal lymph node was 'malignant lymphoma (ML), follicular, small cleaved' according to the Working Formulation. Complete remission was achieved. Although she had relapse in 1992, remission was obtained again. The second case was in a 62-year old man, whose PS was 1, the serum LDH was normal, and Ann Arbor stage was IVA with the involvement of the small intestine. Histological diagnosis of the cervical lymph node was 'ML, diffuse, large cell'. Complete remission was obtained without relapse. The 3q27 translocations, found in 20-30% of non-Hodgkin's lymphoma, are unique in having multiple chromosomal translocation partners. Chromosome band 6p21.3 is one of these partner sites that may be the site of a novel gene. The two cases presented here show that this translocation is a non-random chromosomal change involving 3q27 and BCL6. Since t(3;6) was the sole karyotypic abnormality in one case, this translocation may play a role in lymphomagenesis.     

On the temporal relations between memory scanning and response preparation

Three experiments were conducted to investigate whether response processes can start before memory scanning has finished when both are required in the same task. In Experiment 1 the color of a stimulus letter determined which hand might respond, and the letter's memory set membership determined whether that response should be made or withheld. Electrophysiological data suggested that lateralized response preparation was not initiated until memory scanning finished. Experiment 2 replicated these results with a consistent stimulus-response mapping to make the scanning process easier. Experiment 3 tested for earlier response priming with a probe reaction time paradigm, and the results suggested that color information can be used to activate a response before memory scanning is finished. The results of Experiments 1-3 suggest that interference between memory scanning and response preparation precludes the concurrent operation of these processes.     

Design parameters and measured performance of the IRAM 30-mMillimeter Radio Telescope

The “Millimeter Radio Telescope” (MRT) is operated by the Institute for Radio Astronomy in the millimeter range (IRAM) and is located at 2850-m altitude in the Sierra Nevada, near Granada, Spain. It is a reflector antenna of 30-m diameter with a surface accuracy of 0.08 mm and a pointing accuracy of better than 2 arcsec. The telescope is equipped with sensitive receivers for the atmospheric windows between 0.8- and 7-mm wavelength. The authors describe the optics layout of the receiver and calibration system, which allows simultaneous observations at a number of frequencies. The special design aspects of the antenna, in particular the control of thermal deformations and the achievement of a high reflector and pointing accuracy are described. The authors compare the design computations with the characteristics of the telescope, derived from several years of operation and optimization. The success of the design is demonstrated by observational experience. The authors conclude the paper with a short review of some of the astronomical results obtained with the telescope     

Efficacy of arthroscopic lysis and lavage in patients with temporomandibular joint symptoms associated with generalized osteoarthritis or rheumatoid arthritis

PURPOSE: This study evaluated the efficacy of arthroscopic lysis and lavage in patients with temporomandibular joint (TMJ) symptoms and generalized osteoarthritis (GOA) or rheumatoid arthritis (RA). PATIENTS AND METHODS: Twenty-three GOA patients and 23 RA patients were evaluated after 1 year. RESULTS: Seventeen of 23 patients (74%) in the RA group improved after arthroscopic lysis and lavages compared with 10 of 23 (43%) of the GOA patients. Lateral joint tenderness, crepitation, maximal opening, and maximal protrusion showed most improvement in the RA group. CONCLUSIONS: On the basis of this short-term follow-up study, arthroscopic lysis and lavage seem to provide an effective treatment for TMJ pain and dysfunction in RA patients but not in GOA patients.     

The cache assignment problem and its application to database buffermanagement

Given N request streams and L⩽N LRU caches, the cache assignment problem asks to which cache each stream should be assigned in order to minimize the overall miss rate. An efficient solution to this problem is provided, based on characterizing each stream using the stack reference model and characterizing the interaction of the streams using a bursty stream model. It is shown that for Bernoulli (purely random) mixing of streams, the optimal cache assignment is to have one cache per stream. In practice streams are mixed in a way that is much “burstier” than can be represented by the Bernoulli model. Therefore a method is presented for superposition of bursty streams. The performance of the methods developed for bursty stream superposition and cache assignment are tested using trace data obtained from the database system DB2. The resulting cache assignment recommendations are then applied to the DB2 system, and considerable performance improvement is found to result     

Monitoring and control processes in the strategic regulation of memory accuracy.

When people are allowed freedom to volunteer or withhold information, they can enhance the accuracy of their memory reports substantially relative to forced-report performance. A theoretical framework addressing the strategic regulation of memory reporting is put forward that delineates the mediating role of metamemorial monitoring and control processes. Although the enhancement of memory accuracy is generally accompanied by a reduction in memory quantity, experimental and simulation results indicate that both of these effects depend critically on (a) accuracy incentive and ( b ) monitoring effectiveness. The results are discussed with regard to the contribution of metamemory processes to memory performance, and a general methodology is proposed that incorporates these processes into the assessment of memory-accuracy and memory-quantity performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early modifications of chemokine production and mRNA expression during rush venom immunotherapy

The mechanism by which specific immunotherapy exerts its beneficial effect remains unclear. Chemokines are implicated in inflammatory and allergic diseases, in particular via their ability to induce histamine release from basophils, a potential early target of rush venom immunotherapy (RVIT), In this study, the authors evaluated ex vivo regulated upon activation normal T-cell expressed and secreted (RANTES), interleukin 8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1) production and mRNA expression by mononuclear cells (MNC) from nine patients undergoing a 3.5-h ultra rush treatment, before treatment at Day 0 (D0), at the end of the 3.5-h of the rush at Day 4h (D4h), at Day 15 (D15) and Day 45 (D45) after treatment. Increased RANTES release and mRNA expression were observed in 24-h culture of peripheral blood MNC collected at D4h. This was followed by a decrease in the production of RANTES, IL-8 and MCP-1, 45 days after initiation of RVIT. The same pattern was observed after in vitro venom stimulation of MNC. At the mRNA level, similar profiles were observed except for IL-8 mRNA which inversely increased during RVIT. These results suggest that RVIT is associated with a general decrease in chemokines which may explain, in part, the clinical efficacy of specific immunotherapy.