Response of electrostatic probes to ionized gas flows in a shock tube

In his excellent analysis of electrical measurements in shock tube flows, Hollyer(1) has demonstrated certain pitfalls in the application of conventional Langmuir probe techniques to the evaluation of charge densities in the moving stream of hot gas confined within the tube walls. The purpose of this note is to describe somewhat similar experiments which illustrate other eccentricities in probe behavior under these conditions

Cost-Benefit Analysis of Health Service

"Where my health is concerned, cost is no ob ject." The reply of the penniless man to an expensive spe cialist reflects a moral question. Should the costs of health services be a significant consideration in deciding upon gov ernmental health policies and programs? The answer in my opinion is yes. Costs ought to be used in deciding the level of health activities versus other social goods and services, and in planning which health programs to support. The truly moral problem is not to distinguish between good and evil but rather to select appropriately among alternative goods. After argu ing that consideration of cost is a moral imperative, the useful ness of cost-benefit analysis in framing the right questions and in improving the chances of moving in directions of social improvement is urged, and some limitations are noted. Fi nally, examples of the use of cost-effectiveness analysis in studying problems of disease control and maternal and child health are given.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66632/2/10.1177_000271627239900111.pd

Coplanar constant mean curvature surfaces

We consider constant mean curvature surfaces of finite topology, properly embedded in three-space in the sense of Alexandrov. Such surfaces with three ends and genus zero were constructed and completely classified by the authors in arXiv:math.DG/0102183. Here we extend the arguments to the case of an arbitrary number of ends, under the assumption that the asymptotic axes of the ends lie in a common plane: we construct and classify the entire family of these genus-zero coplanar constant mean curvature surfaces.Comment: 35 pages, 10 figures; minor revisions including one new figure; to appear in Comm. Anal. Geo

Triunduloids: Embedded constant mean curvature surfaces with three ends and genus zero

In 1841, Delaunay constructed the embedded surfaces of revolution with constant mean curvature (CMC); these unduloids have genus zero and are now known to be the only embedded CMC surfaces with two ends and finite genus. Here, we construct the complete family of embedded CMC surfaces with three ends and genus zero; they are classified using their asymptotic necksizes. We work in a class slightly more general than embedded surfaces, namely immersed surfaces which bound an immersed three-manifold, as introduced by Alexandrov.Comment: LaTeX, 22 pages, 2 figures (8 ps files); full version of our announcement math.DG/9903101; final version (minor revisions) to appear in Crelle's J. reine angew. Mat

Constant mean curvature surfaces with three ends

We announce the classification of complete, almost embedded surfaces of constant mean curvature, with three ends and genus zero: they are classified by triples of points on the sphere whose distances are the asymptotic necksizes of the three ends.Comment: LaTex, 4 pages, 1 postscript figur

Cell motility through plasma membrane blebbing

Plasma membrane blebs are dynamic cytoskeleton-regulated cell protrusions that have been implicated in apoptosis, cytokinesis, and cell movement. Influencing Rho–guanosine triphosphatase activities and subsequent actomyosin dynamics appears to constitute a core component for bleb formation. In this paper, we discuss recent evidence in support of a central role of nonapoptotic membrane blebbing for cell migration and cancer cell invasion as well as advances in our understanding of the underlying molecular mechanisms. Based on these studies, we propose that in a physiological context, bleb-associated cell motility reflects a cell's response to reduced substratum adhesion. The importance of blebbing as a functional protrusion is underscored by the existence of multiple molecular mechanisms that govern actin-mediated bleb retraction

Transforming growth factor-beta targets Formin-like 2 for Angiopoietin-like 4 secretion during the epithelial mesenchymal transition

Epithelial to Mesenchymal transition (EMT) is a highly dynamic process that plays a crucial role in tumor progression and metastasis. While remodelling of the actin cytoskeleton is a hallmark of EMT, the responsible actin regulating factors are less well understood. Formins are involved in numerous cellular mechanisms, ranging from cytokinesis to cell adhesion and motility. The Rho-GTPase effectors of the formin family compromise the largest group of actin nucleators and are emerging as relevant pharmacological targets. A critical role of Formin-like 2 (FMNL2) in the assembly of junctional actin at newly forming cell-cell contacts in a 3D matrix has been described. This activity originates downstream of Rac1 and is in line with a physical association of FMNL2 and components of the cadherin-catenin complex. FMNL2 was further recently implicated in β1-integrin trafficking as a direct PKC target required for cancer cell invasion. Here we found that transforming growth factor-beta (TGFβ)-driven EMT leads to an upregulation of PKC resulting in the phosphorylation and activation of FMNL2 in epithelial cells. Proteomic screening for TGFβ-mediated phospho-FMNL2 binding partners identified the tumor promotor ANGPTL4 as a specific binding partner. ANGPTL4 has important roles in cancer development and progression including promoting invasion and metastasis. We found that FMNL2 and ANGPTL4 directly interact under TGF-induced EMT. Our data show that FMNL2 is a critical regulator of ANGPTL4 secretion. Secretion of ANGPTL4 is diminished upon loss of FMNL2 and its phosphorylation. We further observed that ANGPTL4 is sequestered in the Golgi apparatus colocalizing with markers of the trans-Golgi network. Live imaging of vesicle secretion from the Golgi confirmed the transient co-localization of ANGPTL4 and FMNL2. Moreover, ANGPTL4 and FMNL2 modulate cell-cell contact integrity and ANGPTL4 silenced cells fail to disassemble their underlying cell-cell contacts to execute EMT. This effect was further enhanced upon FMNL2 knockout using FMNL2 CRISPR/Cas9 cell line. However, re-introduction of ANGPTL4 restored the mesenchymal phenotype and prompted the dissolution of cell-cell adhesions. Finally, we found that cellular invasion promoted by TGFβ depends on FMNL2 and is reduced upon ANGPTL4 silencing. Taken together, our data point towards a crucial role of FMNL2 for EMT via ANGPTL4 secretion

Emerging Properties and Functions of Actin and Actin Filaments Inside the Nucleus.

Peer reviewe