Affordances, perceptual complexity, and the development of tool use.

Perceiving the affordance of a tool requires the integration of several complementary relationships among actor, tool, and target. Higher order affordance structures are introduced to deal with these forms of complex action from an ecological-realist point of view. The complexity of the higher order affordance structure was used to predict the difficulty of perceiving the tool function. Predictions were tested in 3 experiments involving children between 9 mo and 4 yrs old. In a classical tool use task dating back to W. K?hler (1921), a desirable target was obtained by using a hook as a tool. The relative positions of the hook and the target were systematically varied to obtain structures differing in complexity. The observed difficulty of the task was found essentially in accordance with the theoretical complexity of the higher order affordance structures involved in perceiving the tool function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rapid relief of anxiety in cancer patients with both alprazolam and placebo

This study evaluated 36 cancer patients who were enrolled in a randomized, double-blind, placebo-controlled trial conducted over a 4-week period to evaluate the efficacy of alprazolam in the treatment of anxiety associated with cancer. Hamilton Anxiety Scale scores declined significantly between baseline and the end of the first week of the study in both treatment groups. There was no significant difference in response between the patients receiving alprazolam and placebo. Similar results were obtained from other instruments. These results suggest that nondrug factors or spontaneous improvement may play a more important role than pharmacotherapy in the treatment of anxiety associated with cancer.     

Congenital pulmonary lymphangiectasis with chylothorax: a heterogeneous lymphatic vessel abnormality

We describe the generation of a new antipeptide antibody that binds to the centromeric region of human mitotic chromosomes. This antibody was raised against a synthetic peptide corresponding to the 481-493 amino acid sequence of the human CENP-B autoantigen. Immunofluorescence analysis revealed that this anti-CENP-B serum showed an identical pattern to the human CREST anticentromere autoantibody in both mitotic cells and interphase nuclei. Immunoblotting showed that this antibody reacts with the recombinant human CENP-B autoantigen, indicating that it is directed to the 80-kDa centromere polypeptide. We have used this serum to determine, by indirect immunofluorescence, whether CENP-B is conserved in different mammalian species. Surprisingly, the human antipeptide antibody does not react with the centromeric proteins of cultured mouse, hamster, or Indian muntjac cells. Because the CENP-B gene has been cloned in human and mouse, our results suggest that the CENP-B epitope used as an immunogen in this study is not ubiquitous in mammalian cells, and that we have most probably established a monospecific antibody to the human centromere.     

The C-terminus of c-ABL is required for proliferation and viability signaling in a c-ABL/erythropoietin receptor fusion protein

Activated ABL oncogenes cause B-cell leukemias in mice and chronic myelogenous leukemia in humans. However, the mechanism of transformation is complex and not well understood. A method to rapidly and reversibly activate c-ABL was created by fusing the extra-cytoplasmic and transmembrane domain of the erythropoietin (EPO) receptor with c-ABL (EPO R/ABL). When this chimeric receptor was expressed in Ba/F3 cells, the addition of EPO resulted in a dose-dependent activation of c-ABL tyrosine kinase and was strongly antiapoptotic and weakly mitogenic. To evaluate the contributions of various ABL domains to biochemical signaling and biological effects, chimeric receptors were constructed in which the ABL SH3 domain was deleted (triangle upSH3), the SH2 domain was deleted (triangle upSH2), the C-terminal actin-binding domain was deleted (triangle upABD), or kinase activity was eliminated by a point mutation, K290M (KD). The mutant receptors were stably expressed in Ba/F3 cells and analyzed for signaling defects, proliferation, viability, and EPO-induced leukemia in nude mice. When compared with the ability of the full-length EPO R/ABL receptor to induce proliferation and support viability in vitro, the triangle upSH3 mutant was equivalent, the triangle upSH2 mutant was moderately impaired, and the triangle upABD and KD mutants were profoundly impaired. None of these cell lines caused leukemia in mice in the absence of pharmacological doses of EPO. However, in mice treated with EPO (10 U/d), death from leukemia occurred rapidly with wild-type and triangle upSH3. However, time to death was prolonged by at least twofold for triangle upSH2 and greater than threefold for triangle upABD. This inducible model of ABL transformation provides a method to link specific signaling defects with specific biological defects and has shown an important role for the C-terminal actin-binding domain in proliferation and transformation in the context of this receptor/oncogene.     

Antiproteinuric effect predicts renal protection by angiotensin-converting enzyme inhibition in rats with established adriamycin nephrosis

1. The mechanism of renal protection by angiotensin-converting enzyme inhibition is still the subject of debate. Inhibition of proteinuria might play a role. If so, a good antiproteinuric response to angiotensin-converting enzyme inhibition should predict subsequent protection against renal structural damage. This hypothesis has not been tested in models where treatment is started after the renal disease is well established, i.e. models that mimic the clinical situation. 2. We therefore investigated this hypothesis in 96 male Wistar rats with established adriamycin nephrosis. Reduction of proteinuria was achieved by lisinopril (0, 2, 5 and 10 mg day-1 kg-1) on two different sodium diets (0.3% and 0.05% NaCl). Therapy started 6 weeks after adriamycin (at stable proteinuria) and was continued for 6 weeks. 3. Lisinopril reduced blood pressure by 32 +/- 4% and proteinuria by an average of 72 +/- 7%, with stabilization after 2 weeks. Considerable interindividual differences in antiproteinuric response was found. Glomerulosclerosis score was reduced by 15 +/- 5%. All the effects of angiotensin-converting enzyme inhibitors were enhanced by sodium depletion, but sodium depletion in itself did not affect blood pressure (124 +/- 4 mmHg), proteinuria (664 +/- 68 mg/day) or glomerulosclerosis score (30 +/- 5%). Interestingly, the more proteinuria was reduced initially in an individual rat, the less sclerosis was found in the long term in that rat. 4. In conclusion, angiotensin-converting enzyme inhibition lowers proteinuria and prevents glomerulosclerosis in established adriamycin nephrosis. These effects are enhanced by sodium depletion. The individual short-term antiproteinuric effect predicts the protection against ultimate glomerular damage. This is consistent with the hypothesis that reduction of proteinuria is a mechanism by which angiotensin-converting enzyme inhibitors exert renoprotection.     

Development of Bi(Pb)-2223/Ag pancake-shaped and solenoidal coils

High temperature superconducting (HTSC) multifilamentary (MT) Bi(Pb)-2223/Ag tapes with reproducible critical current density of between 15000 and 20000 A/cm² at 77 K in self field have been achieved using the standard flat-rolling method as the intermediate deformation between sintering periods. Long lengths of Bi(Pb)-2223/Ag MT tapes up to 43 m prepared by the conventional method of powder-in-tube (PIT) have been successfully produced on a laboratory scale. Several coils have been fabricated from sections of the long length tape, using the co-wound wind-and-react (W&R) procedure for the pancake-shaped and the singly-wound W&R as well as R&W procedure for the solenoidal coils. A novel W&R solenoidal coil (reaching ~973 ampere-turns) wound on an alumina ceramic tube generates a DC field of ~19 mT at 77 K and has been fabricated together with five pancake-shaped coils, each generating an average of ~5 mT at 77 K. These are destined for magnet construction with a possible combined calculated field of ~0.04 T at 77 K (with liquid nitrogen as a coolant)     

Power electronic converters for motion control

The historical development of power electronic converters to control electrical machines is traced up to the present state of the technology. The fundamental possibilities to control average power in a switching mode are considered and the concepts switching function, converter topology and converter structure defined. A systematic approach to developing more complicated topologies and structures for singular and composite converters is discussed and application to motion control systems given. A functional classification of motion control converters is also related to the switching nature of the power processing, illustrating the fundamental dilemma of this kind of highly efficient power control. The different control possibilities of using power electronic converters with electrical machines in motion control applications (DC drives, AC drives) are reviewed systematically. The paper does not attempt to compile a comprehensive list of all possible converter circuits and variations but focusses on generic issues and technologies. The switching technology in converters and its limitations is related to snubberless, snubbed, and resonant transition-type operation, with reference also to switch drive and converter protection technology. Some future generic possibilities related to electromagnetic integration of switching converters are discussed, also in relation to a motion control application     

On the hot-carrier-induced post-stress interface trap generation inn-channel MOS transistors

A continued fast interface trap generation is observed in n-channel MOS transistors after termination of the hot-carrier stress. The magnitude of this post-stress effect is strongly dependent on the conditions of the preceding stress, on the post-stress conditions and on the process parameters. For measurements at 293 K, a simple model is proposed which is based on the release of hydrogen by the thermal detrapping of holes, and which can explain the observed dependencies. The importance of the post-stress D_it-generation is illustrated for the case of dynamic stress conditions where it can lead to an apparently deviating degradation behavior     

Five new optimal ternary linear codes

Optimal ternary linear codes with parameters [29,5,18], [34,5,21], [43,5,27], [61,5,39], and [31,6,18] have been found. Codes with these parameters were not known until now