A calibrated Monte Carlo approach to quantify the impacts of misorientation and different driving forces on texture development

A calibrated Monte Carlo (cMC) approach, which quantifies grain boundary kinetics within a generic setting, is presented. The influence of misorientation is captured by adding a scaling coefficient in the spin flipping probability equation, while the contribution of different driving forces is weighted using a partition function. The calibration process relies on the established parametric links between Monte Carlo (MC) and sharp-interface models. The cMC algorithm quantifies microstructural evolution under complex thermomechanical environments and remedies some of the difficulties associated with conventional MC models. After validation, the cMC approach is applied to quantify the texture development of polycrystalline materials with influences of misorientation and inhomogeneous bulk energy across grain boundaries. The results are in good agreement with theory and experiments.     

Bücherschau

Ohne Zusammenfassung VDI     

The PUMILIO-RNA interaction: a single RNA-binding domain monomer recognizes a bipartite target sequence

Translational repression of hunchback (hb) mRNA in the posterior of the Drosophila embryo requires two copies of a bipartite sequence, the Nanos Response Element (NRE), located in the 3' untranslated region of the mRNA. The PUMILIO (PUM) protein is thought to bind the NREs and thereby repress hb translation. The RNA-binding domain of PUM defines an evolutionarily conserved family of RNA-binding proteins, the PUM-Homology Domain (PUM-HD) proteins, which have been identified in yeast, plants, and animals. The PUM RNA-binding domain, the Drosophila PUM-HD (DmPUM-HD), has been shown previously to recognize nucleotides in both the 5' and 3' halves of the NRE, suggesting that a dimer of PUM might recognize one NRE. Here, we analyze the RNA-binding affinity and stoichiometry of the DmPUM-HD and find that one DmPUM-HD monomer binds independently and with equal affinity to each NRE (KD approximately 0.5 nM). We detect no cooperative interactions between DmPUM-HD monomers bound at adjacent sites. Our results imply that a single DmPUM-HD protein recognizes nucleotides in both the 5' and 3' NRE half-sites. Based on our estimate of the intraembryonic concentration of PUM (>40 nM), we propose that in vivo nearly all NREs are occupied by a PUM monomer.     

Wireless Andrew: Building a High Speed, Campus-Wide Wireless Data Network

Carnegie Mellon University (CMU) has a major program to create a high speed wireless network, known as Wireless Andrew. The first Phase of this network has been operational for over a year and the second Phase, to upgrade this to IEEE 802.11 standard technology, has begun. The Wireless Andrew network uses wireless local area network technology, utilizing spread spectrum in the ISM band. The purpose is not only to support wireless research but also to create a campus-wide mobile computing laboratory.The paper shows the challenge of designing and managing large scale wireless networks. The examples show the differences experienced in wireless versus wireline networks due to the nature of mobility versus static components, the nature of RF propagation versus wireline connection, and the difference in sophistication of tools because of the different place in the product development cycle. The paper describes the lessons learned at completion of the first phase including: installation design issues, issues of RF interference and data throughput, the unique problems of wireless network management, and the release of the system. The paper goes on to describe lessons learned during the first year of operation of the research network. It then discusses experience so far in Phase Two, to create an operational utility for use of all students, faculty, and staff for educational, research, and administrative applications.     

Clinical, psychological, and psychophysiological characteristics of neurotic-functional, cardiovascular and neurotic-depressive syndromes

A total of ninety women classified into three groups (with cardiovascular, depressive, and other principal symptoms) according to clinical criteria were characterized by clinico-anamnestic, psychological, and psychophysiological data with the goal of arriving at a practically oriented differentiation of neurotic syndromes. The relevant variables were determined by means of a factor analysis. The physiological reaction patterns determined in experiments on psychically strained individuals proved unsuitable for the differentiation of the two syndromes. The problems associated with a symptom-oriented classification are discussed.     

EGF-R and PCNA expression in ovarian carcinomas--correlation with classic prognostic factors

Expression of the epidermal growth factor-receptor (EGF-R) and the proliferating cell nuclear antigen (PCNA) was immunohistochemically studied in 75 ovarian cancer samples using formalin-fixed, parafin-embedded tissue. Correlations between these factors and conventional histomorphologic factors were investigated. 44 (58.7%) tumors were EGF-R positive (> 10% positive cells). 18 tumors (24%) showed a weak EGF-R-expression (< or = 50% positivity) and 26 tumors (34.7%) had a strong EGF-R-expression. Expression of EGF-R did not correlate with any of the other prognostic factors investigated. The PCNA-proliferative fraction was classified using the median value (< or = 34%/ > 34%) and a categorization in three groups (< 20%/20%-50%/ > 50%). PCNA-expression showed no correlation with FIGO-stage, histologic tumor type, lymph node-status and EGF-R. However, both PCNA-classifications correlated with the size of the residual tumor (PCNA < or = 34%/ > 34%/p = 0.046; PCNA < 20%/20%-50%/ > 50%/p = 0.086) and the histologic grading (p = 0.076; p = 0.02 respectively). Thus, the PCNA-proliferative fraction might be an additional indicator for tumor aggressiveness and disease outcome.     

Ultrastructure of the glial cells after spinal cord compression in rabbits

Sump syndrome is a rare complication of biliary-enteric anastomosis. Classically, the distal bile duct becomes obstructed by gastrointestinal debris after choledochoduodenostomy, resulting in cholangitis or, less commonly pancreatitis. Obstruction of the biliary tree by gastrointestinal contents after Roux-en-Y choledochojejunostomy or hepaticojejunostomy has not been described in the English-language literature. This report details the diagnostic and operative management of the first patient with sump syndrome after hepaticojejunostomy. The presumed pathophysiology was reflux of vegetable matter up the efferent limb, resulting in hepatic duct obstruction and cholangitis. The patient ultimately required complex choledochoscopic drainage of the intrahepatic biliary tree and revision of the previous Roux-en-Y hepaticojejunostomy.     

Defect detection in multilayer ceramic capacitors

Cracks in Multilayer Capacitors are often latent defects, which are not recognized in production, but can cause substantial problems in field. Therefore it is important to find possibilities to detect those candidates before delivering electronic equipment.In this work, cracked capacitors were characterized by electrical parameter testing and by piezoelectric spectroscopy. As a new method, sound emission spectroscopy was employed as indicator for latent defects and correlated with electrical data and physical analysis. The results show that sound emission used on a statistical basis and piezoelectric response might be effective to screen latent defects in electronic control units.