Psychosocial rehabilitation of cranial trauma and stroke patients

This paper presents the results of a longitudinal psychosocial study of 22 cranial trauma patients and 14 stroke patients from the time preceding injury (using retrospective data), through a 4-5 month intensive rehabilitation programme, to a follow-up 1 year after completion of the programme. Although the two groups of patients differed on several demographic and medical characteristics, essentially similar patterns for psychosocial decline following injury and improvement following rehabilitation could be observed. For both groups, the proportion in marital or cohabitational relationships returned to pre-injury levels, and for both groups the proportion requiring assistance in their living situation declined following rehabilitation, as did use of the health services. Virtually all patients in both groups had been in employment or undergoing education at the time of the injury, and although this percentage declined in practice to a small minority of both groups post-injury, there was a significant increase in the proportions working or in education following the rehabilitation programme. Similarly, the pattern of leisure-time activities in both groups declined post-injury and was restored following rehabilitation. Since both groups entered the programme at over 2.5 years post-injury, these generally encouraging results seem less likely to reflect spontaneous recovery than a beneficial effect of the programme itself.     

Electron-Impact Cross Sections for Dipole- and Spin-Allowed Excitations of Hydrogen,Helium, and Lithium

Electron-impact excitation cross sections are presented for the dipole- and spin allowed transitions from the ground states to the np ²P states for hydrogen and lithium, and to the 1snp ¹P states for helium, n = 2 through 10. Two scaling formulas developed earlier by Kim [Phys. Rev. A 64, 032713 (2001)] for plane-wave Born cross sections are used. The scaled Born cross sections are in excellent agreement with available theoretical and experimental data.     

Selective interactions among the multiple connexin proteins expressed in the vertebrate lens: the second extracellular domain is a determinant of compatibility between connexins

Gap junctions are collections of intercellular channels composed of structural proteins called connexins (Cx). We have examined the functional interactions of the three rodent connexins present in the lens, Cx43, Cx46, and Cx50, by expressing them in paired Xenopus oocytes. Homotypic channels containing Cx43, Cx46, or Cx50 all developed high conductance. heterotypic channels composed of Cx46 paired with either Cx43 or Cx50 were also well coupled, whereas Cx50 did not form functional channels with Cx43. We also examined the functional response of homotypic and heterotypic channels to transjunctional voltage and cytoplasmic acidification. We show that all lens connexins exhibited sensitivity to cytoplasmic acidification as well as to voltage, and that voltage-dependent closure of heterotypic channels for a given connexin was dramatically influenced by its partner connexins in the adjacent cell. Based on the observation that Cx43 can discriminate between Cx46 and Cx50, we investigated the molecular determinants that specify compatibility by constructing chimeric connexins from portions of Cx46 and Cx50 and testing them for their ability to form channels with Cx43. When the second extracellular (E2) domain in Cx46 was replaced with the E2 of Cx50, the resulting chimera could no longer form heterotypic channels with Cx43. A reciprocal chimera, where the E2 of Cx46 was inserted into Cx50, acquired the ability to functionally interact with Cx43. Together, these results demonstrate that formation of intercellular channels is a selective process dependent on the identity of the connexins expressed in adjacent cells, and that the second extracellular domain is a determinant of heterotypic compatibility between connexins.     

Parallel implementation of large-scale structural optimization

Advances in computer technology and performance allow researchers to pose useful optimization problems that were previously too large for consideration. For example, NASA Langley Research Center is investigating the large structural optimization problems that arise in aircraft design. The total number of design variables and constraints for these nonlinear optimization problems is now an order of magnitude larger than anything previously reported. To find solutions in a reasonable amount of time, a coarse-grained parallel-processing algorithm is recommended. This paper studies the effects of problem size on sequential and parallel versions of this algorithm.For initial testing of this algorithm, a hub frame optimization problem is devised such that the size of the problem can be adjusted by adding members and load cases. Numerous convergence histories demonstrate that the algorithm performs correctly and in a robust manner. Timing profiles for a wide range of randomly generated problems highlight the changes in the subroutine timings that are caused by the increase in problem size. The potential benefits and drawbacks associated with the parallel approach are summarized.     

Using LADAR to characterize the 3-D shape of aggregates: Preliminary results

Previous publications have shown how a combination of X-ray computed tomography and spherical harmonic series could be used to characterize the 3-D shape of rocks used for aggregates in concrete. The X-ray computed tomography was used to obtain the raw 3-D numerical data for the coordinates of the aggregate surface. In this paper, we demonstrate how laser detection and ranging (LADAR) numerical data can replace X-ray computed tomography data and be used in conjunction with spherical harmonic series analysis to analyze the 3-D shape of aggregates.     

P2X3 is expressed by DRG neurons that terminate in inner lamina II

The P2X3 receptor subunit, a member of the P2X family of ATP-gated ion channels, is almost exclusively localized in sensory neurons. In the present study, we sought to gain insight into the role of P2X3 and P2X3-containing neurons in sensory transmission, using immunohistochemical approaches. In rat dorsal root ganglia (DRG), P2X3-immunoreactivity (-ir) was observed in small- and medium-sized neurons. Approximately 40% of DRG neuronal profiles in normal rats contained P2X3-ir. In rats that had received neonatal capsaicin treatment, the number of P2X3-positive neurons was decreased by approximately 70%. Analysis of the colocalization of P2X3-ir with cytochemical markers of DRG neurons indicated that approximately 94% of the P2X3-positive neuronal profiles were labelled by isolectin B4 from Bandeiraea simplicifolia, while only 3% contained substance P-ir, and 7% contained somatostatin-ir. In dorsal horn of rat spinal cord, P2X3-ir was observed in the inner portion of lamina II and was reduced subsequent to dorsal rhizotomy, as well as subsequent to neonatal capsaicin treatment. Finally, P2X3-ir accumulated proximal to the site of sciatic nerve ligation, and was seen in nerve fibres in skin and corneal epithelium. In summary, our results suggest that P2X3 is expressed by a functionally heterogeneous population of BSI-B4-binding sensory neurons, and is transported into both central and peripheral processes of these neurons.