An in vitro model for toxin-mediated vascular leak syndrome: ricin toxin A chain increases the permeability of human endothelial cell monolayers

Vascular leak syndrome (VLS) is the dose-limiting toxicity observed in clinical trials of immunotoxins containing ricin toxin A chain (RTA). RTA itself is thought to cause VLS by damaging vascular endothelial cells, but the exact mechanism remains unclear. This is partially due to the paucity of appropriate models. To study VLS, we developed an in vitro model in which human umbilical vein-derived endothelial cells were first grown to confluence on microporous supports and then cultured under low pressure in the presence or absence of RTA. Endothelial cell barrier function was assessed by measuring the volume of fluid that passed through each monolayer per unit time. We found that RTA significantly increased monolayer permeability at times and concentrations consistent with the onset of VLS in patients treated with RTA-based immunotoxins. Scanning electron microscopy showed that intercellular gaps formed in endothelial monolayers exposed to RTA. Intercellular gap formation followed endothelial cell death caused by the enzymatic activity of RTA. We conclude that RTA is directly toxic to endothelial cells in vitro and speculate that this contributes to VLS in vivo.     

Review of The saturated self: Dilemmas of identity in contemporary life.

Reviews the book, The saturated self: Dilemmas of identity in contemporary life by Kenneth J. Gergen (see record 1991-97621-000). There is, perhaps, no other concept as seminal for psychology as the self. For this reason alone, Kenneth Gergen's book represents an important contribution to our understanding of this influential concept. However, Gergen's vision is so broad, his arguments so compelling, and the implications so revolutionary, that the work defies confinement exclusively within the walls of academia. In essence, Gergen is articulating his vision of a postmodern world, and he lays an invitation squarely before the reader to come and partake. The conception of the self as private and autonomous is the focus of Gergen's postmodern challenge. In his chapter, "Social Saturation and the Populated Self," Gergen postulates that technological innovation in contemporary society has made possible a rapid proliferation of relationships. This he refers to as the "process of social saturation." Gergen's book constitutes a substantive contribution to psychology's on going understanding of the self. Copious examples are provided throughout, drawing on and extending scholarly debates. Also included are anecdotes and evidences from such far ranging domains as art, film, music, literature, and architecture. These not only clarify and reinforce his arguments, but also illustrate the scope and practicality of the position he espouses. Although readers may not embrace the gestalt of Gergen's vision of a postmodern culture, they are certain to find this book to be a provocative and rewarding read. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phylogenetic analyses of the matrix and non-structural genes of equine influenza viruses

Matrix (M) and nonstructural (NS) genes of thirteen equine H3N8 and H7N7 influenza viruses were sequenced and analyzed from an evolutionary point of view. The M and NS genes of H3N8 viruses isolated between 1989 and 1993 evolved into two minor branch clusters, including isolates from Europe and the American continent, respectively. It was noteworthy to reveal that the nucleotide sequences of the M and NS genes of an earlier American strain showed highest homology to those of recent European viruses. "Frozen evolution" was observed in the M and NS genes of A/eq/LaPlata/1/88. It was also evident that the NS gene of an H7N7 virus from 1977 was very similar to that of a 1979-H3N8 virus, while the M gene was closest phylogenetically to that of the earliest H7N7 virus isolated in 1956. Furthermore, the M2 protein of A/eq/Newmarket/1/77 virus contained a carboxyl terminal deletion of three amino acids. The evolutionary rates of the M and NS genes of H3N8 equine influenza viruses were estimated to be 5.4 x 10(-4) and 5.1 x 10(-4) substitutions per site per year, respectively, which were slower than those of human viruses.     

Topological spines: a structure-preserving visual representation of scalar fields

We present topological spines--a new visual representation that preserves the topological and geometric structure of a scalar field. This representation encodes the spatial relationships of the extrema of a scalar field together with the local volume and nesting structure of the surrounding contours. Unlike other topological representations, such as contour trees, our approach preserves the local geometric structure of the scalar field, including structural cycles that are useful for exposing symmetries in the data. To obtain this representation, we describe a novel mechanism based on the extraction of extremum graphs--sparse subsets of the Morse-Smale complex that retain the important structural information without the clutter and occlusion problems that arise from visualizing the entire complex directly. Extremum graphs form a natural multiresolution structure that allows the user to suppress noise and enhance topological features via the specification of a persistence range. Applications of our approach include the visualization of 3D scalar fields without occlusion artifacts, and the exploratory analysis of high-dimensional functions.     

A DSS for integrated distribution of empty and full containers

A DSS integrating empty and full containers transshipment operations is presented, addressing the typically unbalanced export/import containers trading problem. The problem is modeled as a network, where nodes represent customers, leasing companies, harbors and warehouses, while arcs represent transportation routes. The underlying mathematical model operates in stages, first prioritizing and adjusting full containers demands considering available empty containers supplies, and then statically optimizing costs. Transportation routes are registered and dynamically controlled, cyclically, for a given time horizon. The DSS is flexible, allowing several parameters to be configured. Experimental examples using randomly generated parameters were conducted to evaluate the effectiveness of the system.     

Preparation and Certification of Hydrogen in Titanium Alloy Standard Reference Materials

A series of three hydrogen in titanium alloy Standard Reference Materials (SRMs 2452, 2453, and 2454) was prepared with hydrogen mass fractions bracketing the hydrogen specification limit of 125?mg/kg. Commercial titanium alloy Ti6Al4V (6?pct aluminum and 4?pct vanadium) was heated under vacuum in a furnace to remove native hydrogen, then it was doped with a measured quantity of hydrogen. Prompt gamma-ray activation analysis was used to determine hydrogen in the degassed material and finished SRMs. A combination of preparation data and PGAA measurement was used to certify the hydrogen mass fraction of each. The certified hydrogen mass fractions are 62.5?mg/kg?±?1.6?mg/kg for SRM 2452, 114?mg/kg?±?5?mg/kg for SRM 2453, and 211?mg/kg?±?4?mg/kg for SRM 2454.     

数字资源管理——无纸办公室成为现实

当个人电脑在20世纪70年代还完全是一种新玩意儿时,“无纸办公室”就很快成了一个时髦的说法。数字资源管理(Digital Asset Management,缩写为DAM)这一概念则在是20世纪90年代形成的,带有许多与无纸办公室相类似的含义。而且,这一概念刚出现时也同样被大肆炒作过,其变为现实的速度也同样不像预期的那样迅猛。那么,它是不是也会像无纸办公室那样遭遇同样的命运呢?     

Zipper: A compact connectivity data structure for triangle meshes

We propose Zipper, a compact representation of incidence and adjacency for manifold triangle meshes with fixed connectivity. Zipper uses on average only 6 bits per triangle, can be constructed in linear space and time, and supports all standard random-access and mesh traversal operators in constant time. Similarly to the previously proposed LR (Laced Ring) approach, the Zipper construction reorders vertices and triangles along a nearly Hamiltonian cycle called the ring. The 4.4× storage reduction of Zipper over LR results from three contributions. (1) For most triangles, Zipper stores a 2-bit delta (plus three additional bits) rather than a full 32-bit reference. (2) Zipper modifies the ring to reduce the number of exceptional triangles. (3) Zipper encodes the remaining exceptional triangles using 2.5× less storage. In spite of these large savings in storage, we show that Zipper offers comparable performance to LR and other data structures in mesh processing applications. Zipper may also serve as a compact indexed format for rendering meshes, and hence is valuable even in applications that do not require adjacency information.