Endovascular interventions training and credentialing for vascular surgeons

This article reviews issues concerning the training and credentialing of vascular surgeons in the use of endovascular techniques in the peripheral vascular system. These guidelines update a prior document that was published in 1993. They have been rewritten to accommodate the rapid evolution that has occurred in the field and to provide the appropriate requirements that a vascular surgeon should fulfill to be competent in the basic skills needed to safely and effectively perform all presently accepted diagnostic and therapeutic endovascular procedures.     

Osteoporosis for the allergist

OBJECTIVE: This review is intended to be an authoritative summary of the pathogenesis of osteoporosis, a problem that may be encountered in allergy practice. It also provides an outline for identification of subjects at high risk and directions for their appropriate evaluation, management, and prevention of the disease. DATA SOURCES: References were obtained through a MEDLINE literature search as well as from previous reviews. Relevant articles were critically reviewed and their conclusions were included. RESULTS: Osteoporosis is a relatively common disease that is associated with significant morbidity and mortality. The management and prevention of osteoporosis have been improved by an increased awareness of the magnitude of the problem, a better understanding of the pathogenesis, development of a better technique for assessment of bone mineral density, and the availability of specific medications. With the increase in human life-span and the increasing use of glucocorticosteroids for a wide variety of diseases, the incidence of osteoporosis has been on the rise. CONCLUSION: Glucocorticosteroids are the most common medications that cause or contribute to the pathogenesis of osteoporosis and have been widely used in allergy practice. It is important for physicians to appreciate the current basic understanding of osteoporosis and to be able to identify patients at high risk for this serious disorder, and to initiate appropriate intervention at a sufficiently early time to be effective. Medications for treatment and prevention of osteoporosis include: calcium, vitamin D, estrogen, bisphosphonates, calcitonin, and others are reviewed in this article.     

Immunodiagnostic methods for detection of 5-enolpyruvylshikimate-3-phosphate synthase in Roundup Ready® soybeans

We have developed immunological-based detection methods to support labeling of protein-containing food fractions derived from Roundup Ready® soybeans. Western blotting and enzyme linked immunosorbent assay (ELISA) procedures were developed to measure the 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) protein derived from the Agrobacterium sp. strain CP4 in the major processed fractions derived from Roundup Ready soybean. Expression of the CP4 EPSPS protein confers tolerance to Roundup® herbicide. The western blotting method utilizes a polyclonal goat anti-CP4 EPSPS antibody which specifically binds to CP4 EPSPS followed by detection of bound goat antibody with biotinylated Protein-G. Detection of this complex is accomplished using horseradish-peroxidase (HRP) labeled NeutrAvidin™ and signal development by enhanced chemiluminesence. Data from western blot analyses of these fractions establish that stable epitopes remain after the seed has been subjected to processing conditions typically employed by the food industry, thereby enabling development of an ELISA method. The ELISA for measurement of CP4 EPSPS is a triple antibody sandwich procedure utilizing a monoclonal capture antibody and a polyclonal detection antibody followed by a third biotin labeled monoclonal anti-rabbit antibody. Sandwich formation is detected using HRP labeled NeutrAvidin™ with color development using TMB substrate. In the sandwich ELISA, the immunological activity of CP4 EPSPS was reduced by the extraction method required to solubilize CP4 EPSPS protein from processed fractions. Sensitivity of the CP4 EPSPS ELISA was sufficient to detect CP4 EPSPS protein in processed soybean fractions that contained 2% Roundup Ready soybean mixed with conventional processed soybean fractions, thereby making the ELISA an acceptable method to assess CP4 EPSPS protein in processed soybean fractions. Data on sensitivity, accuracy, precision and specificity, established that the western blot and ELISA methods are appropriate for compliance with the EC Novel Foods Regulation.     

Rasterkraftmikroskopie im Vakuum an plasmabehandeltem und metallisiertem Polycarbonat

Atomic force microscopy under UHV conditions on plasma etched and metallised polycarbonate The paper describes different AFM modes of operations (static ?contact”? mode and dynamic mode). The influence of ECR plasma treatment and Almetallisation is shown on polycarbonate. The plasma etching changes the surface morphology in the nm scale. Aluminum that exhibits low adhesion to the polycarbonate could be resolved only by AFM in the dynamic mode of operation.     

Can duplex scan arterial mapping replace contrast arteriography as the test of choice before infrainguinal revascularization?

PURPOSE: Arteriography is the diagnostic test of choice before lower extremity revascularization, because it is a means of pinpointing stenotic or occluded arteries and defining optimal sites for the origin and termination of bypass grafts. We evaluated whether a duplex ultrasound scan, used as an alternative to arteriography, could be used as a means of accurately predicting the proximal and distal anastomotic sites in patients requiring peripheral bypass grafts and, therefore, replace standard preoperative arteriography. METHODS: Forty-one patients who required infrainguinal bypass grafts underwent preoperative duplex arterial mapping (DAM). Based on these studies, an observer blinded to the operation performed predicted what operation the patient required and the best site for the proximal and distal anastomoses. These predictions were compared with the actual anastomotic sites chosen by the surgeon. RESULTS: Whether a femoropopliteal or an infrapopliteal bypass graft was required was predicted correctly by means of DAM in 37 patients (90%). In addition, both anastomotic sites in 18 of 20 patients (90%) who had femoropopliteal bypass grafts and 5 of 21 patients (24%) who had infrapopliteal procedures were correctly predicted by means of DAM. CONCLUSION: DAM is a reliable means of predicting whether patients will require femoropopliteal or infrapopliteal bypass grafts, and, when a patient requires a femoropopliteal bypass graft, the actual location of both anastomoses can also be accurately predicted. Therefore, DAM appears able to replace conventional preoperative arteriography in most patients found to require femoropopliteal reconstruction. Patients who are predicted by means of DAM to require crural or pedal bypass grafts should still undergo preoperative contrast studies to confirm these results and to more precisely locate the anastomotic sites.     

Estimating aboveground carbon in a catchment of the Siberian forest tundra: Combining satellite imagery and field inventory

This study was part of an interdisciplinary research project on soil carbon and phytomass dynamics of boreal and arctic permafrost landscapes. The 45 ha study area was a catchment located in the forest tundra in northern Siberia, approximately 100 km north of the Arctic Circle.The objective of this study was to estimate aboveground carbon (AGC) and assess and model its spatial variability. We combined multi-spectral high resolution remote sensing imagery and sample based field inventory data by means of the k-nearest neighbor (k-NN) technique and linear regression.Field data was collected by stratified systematic sampling in August 2006 with a total sample size of n = 31 circular nested sample plots of 154 m² for trees and shrubs and 1 m² for ground vegetation. Destructive biomass samples were taken on a sub-sample for fresh weight and moisture content. Species-specific allometric biomass models were constructed to predict dry biomass from diameter at breast height (dbh) for trees and from elliptic projection areas for shrubs.Quickbird data (standard imagery product), acquired shortly before the field campaign and archived ASTER data (Level-1B product) of 2001 were geo-referenced, converted to calibrated radiances at sensor and used as carrier data. Spectral information of the pixels which were located in the inventory plots were extracted and analyzed as reference set. Stepwise multiple linear regression was applied to identify suitable predictors from the set of variables of the original satellite bands, vegetation indices and texture metrics. To produce thematic carbon maps, carbon values were predicted for all pixels of the investigated satellite scenes. For this prediction, we compared the kNN distance-weighted classifier and multiple linear regression with respect to their predictions.The estimated mean value of aboveground carbon from stratified sampling in the field is 15.3 t/ha (standard error SE = 1.50 t/ha, SE% = 9.8%). Zonal prediction from the k-NN method for the Quickbird image as carrier is 14.7 t/ha with a root mean square error RMSE = 6.42 t/ha, RMSE_r = 44%) resulting from leave-one-out cross-validation. The k-NN-approach allows mapping and analysis of the spatial variability of AGC. The results show high spatial variability with AGC predictions ranging from 4.3 t/ha to 28.8 t/ha, reflecting the highly heterogeneous conditions in those permafrost-influenced landscapes. The means and totals of linear regression and k-NN predictions revealed only small differences but some regional distinctions were recognized in the maps.     

Online segmentation of time series based on polynomial least-squares approximations

The paper presents SwiftSeg, a novel technique for online time series segmentation and piecewise polynomial representation. The segmentation approach is based on a least-squares approximation of time series in sliding and/or growing time windows utilizing a basis of orthogonal polynomials. This allows the definition of fast update steps for the approximating polynomial, where the computational effort depends only on the degree of the approximating polynomial and not on the length of the time window. The coefficients of the orthogonal expansion of the approximating polynomial-obtained by means of the update steps-can be interpreted as optimal (in the least-squares sense) estimators for average, slope, curvature, change of curvature, etc., of the signal in the time window considered. These coefficients, as well as the approximation error, may be used in a very intuitive way to define segmentation criteria. The properties of SwiftSeg are evaluated by means of some artificial and real benchmark time series. It is compared to three different offline and online techniques to assess its accuracy and runtime. It is shown that SwiftSeg-which is suitable for many data streaming applications-offers high accuracy at very low computational costs.     

World lines

In this paper we present World Lines as a novel interactive visualization that provides complete control over multiple heterogeneous simulation runs. In many application areas, decisions can only be made by exploring alternative scenarios. The goal of the suggested approach is to support users in this decision making process. In this setting, the data domain is extended to a set of alternative worlds where only one outcome will actually happen. World Lines integrate simulation, visualization and computational steering into a single unified system that is capable of dealing with the extended solution space. World Lines represent simulation runs as causally connected tracks that share a common time axis. This setup enables users to interfere and add new information quickly. A World Line is introduced as a visual combination of user events and their effects in order to present a possible future. To quickly find the most attractive outcome, we suggest World Lines as the governing component in a system of multiple linked views and a simulation component. World Lines employ linking and brushing to enable comparative visual analysis of multiple simulations in linked views. Analysis results can be mapped to various visual variables that World Lines provide in order to highlight the most compelling solutions. To demonstrate this technique we present a flooding scenario and show the usefulness of the integrated approach to support informed decision making.