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.     

Isothermal Titration Calorimetry and Fluorescence Spectroscopy Study of Asphaltene Self-Association in Toluene and Interaction with a Model Resin

This article collects the work performed by Isothermal Titration Calorimetry (ITC) in the study of the self-association of asphaltenes in toluene solutions. Calorimetric experiments show that asphaltenes start self-associating at very low concentrations and that the existence of a Critical Micellar Concentration is rather improbable. The influence of the water dissolved in the toluene has been studied but the difficulties in keeping the water concentration low hinder the discussion of the results. The calorimetry data have been treated with a simple dimer dissociation model and compared with the results of the titration of three model molecules: nonylphenol, which associates by means of hydrogen bond formation, and coronene and pyrene, which associates by stacking. The results obtained leave open the question about the model-stacking molecules, as it was not possible to elucidate whether they do not associate or the dilution effect does not break the aggregates. The fluorescence spectroscopy results support the results of calorimetry with respect to the self-association at low concentrations. ITC has been applied for the first time to the study of the interaction between asphaltenes and a model resin, namely nonylphenol.     

Calmodulin is essential for estrogen receptor interaction with its motif and activation of responsive promoter

Calmodulin (CaM) has been reported to have affinity for the estrogen receptor (ER). Observations reported here reveal a direct physical interaction between purified CaM and ER. This direct ER-CaM interaction may be an initial event preceding the assembly of ER plus auxiliary proteins into the active ER complex with its DNA motif, the estrogen response element. We demonstrate that CaM is an integral component of this complex by using a system reconstituted from purified ER and nuclear extract from ER-negative breast cancer cells and also with ER-depleted nuclear extract of an ER-positive breast cancer cell line. Although CaM is essential for formation of this complex, it is not sufficient, suggesting roles also of auxiliary proteins. CaM also is functionally required for activation of an ER-responsive promoter, in the 17beta-estradiol-ER pathway of hormone action and regulation of 17beta-estradiol-responsive gene expression that is associated with proliferation of mammary epithelial cells.     

The basic principles of the synapses federated healthcare record server

The NIGHTINGALE Project (NIGHTINGALE Project: HC1109 DGXIII Contract and Technical Annex, European Commission, December 1995) which started on the 1st of January, 1996, after the approval of the European Commission, has a 36 month duration. It is essential in planning and implementing a strategy in training the nursing profession in using and applying healthcare information systems. NIGHTINGALE contributes towards the appropriate use of the developed telematics infrastructure across Europe by educating and training nurses in a harmonious way across Europe in the upcoming field of nursing informatics. NIGHTINGALE develops courseware material based on the curriculum development process using multimedia technologies. Computer based training software packages in nursing informatics will be the basis of the training material and the corresponding courses. CD-ROM based training and reference material will also be provided in the courses whereas the traditional booklets, teaching material and textbooks can also play an adequate role in training. NIGHTINGALE will disseminate all information and courseware material freely to all interested parties through the publications of the proceedings of the conferences, through the establishment of the world wide web (WWW) server in nursing informatics for Europe (http://www.dn.uoa.gr/nightingale), which will become a depository of nursing information knowledge across Europe as well as a dissemination node of nursing informatics throughout the European members states for the benefit and welfare of the European citizen.