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Procedures Used (procedure + used)
Kinds of Procedures Used Selected AbstractsIMMIGRANTS FLEEING A DYING INDUSTRY: APPLYING RAPID ETHNOGRAPHIC ASSESSMENT PROCEDURES TO THE STUDY OF TOBACCO FARMWORKERSANNALS OF ANTHROPOLOGICAL PRACTICE, Issue 1 2009David GriffithArticle first published online: 13 JUL 200 Recent assaults on the tobacco industry have led to a decline in tobacco production across North Carolina, the largest tobacco producing state in the nation. Although a great deal of attention has been focused on tobacco farmers, considerably less work has been aimed at determining the effects of these changes on tobacco farmworkers, many of whom are Latinos. In this article, I discuss Rapid Ethnographic Assessment Procedures used to estimate the impact of changes in the tobacco industry on tobacco farmworkers. I find that the tobacco farm labor force is highly complex and that the effects of the economic downturns have had fewer effects on Latino farmworkers than on tobacco farm owners, in part because of the Latinization of the rural South. [source] A geomorphological framework for river characterization and habitat assessmentAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 5 2001J.R. Thomson Abstract 1.,Methods to assess the physical habitat available to aquatic organisms provide important tools for many aspects of river management, including river health monitoring, determination of river restoration/rehabilitation strategies, setting and evaluating environmental flows and as surrogates for biodiversity assessment. 2.,Procedures used to assess physical habitat need to be ecologically and geomorphologically meaningful, as well as practicable. A conceptual methodological procedure is presented that evaluates and links instream habitat and geomorphology. 3.,The heterogeneity of habitat potential is determined within geomorphic units (such as pools, runs, riffles) by assessing flow hydraulics and substrate character. These two variables are integrated as hydraulic units , patches of uniform flow and substrate. 4.,This methodology forms a logical extension of the River Styles framework that characterizes river form and behaviour at four inter-related scales: catchments, landscape units, River Styles (reaches) and geomorphic units. As geomorphic units constitute the basis to assess aquatic habitat availability, and they form the building blocks of river and floodplain systems, intact reaches of a particular River Style should have similar assemblages of instream and floodplain habitat. 5.,An application of the hydraulic unit procedure is demonstrated in gorge, partly-confined and alluvial River Styles from the Manning catchment in northern New South Wales, Australia. Copyright © 2001 John Wiley & Sons, Ltd. [source] Approach to procedures in neonatesDERMATOLOGIC THERAPY, Issue 2 2005Valerie B. Lyon ABSTRACT:, Physical constraints and metabolic differences in neonates require that special attention is given to performing procedures in this patient group. Neonates have a thinner dermis and a greater surface-to-weight ratio, allowing for easier invasion through the skin barrier. The enzymes for metabolism of agents and defense against organisms inside the body are not fully developed in infants. Very premature neonates also have less circulating albumin, making the effective concentration of circulating agent even greater. The infant is prone to unanticipated movement during procedures, such as rolling on the procedure table. The neonatal period is the most common time period for malformations to become manifest on the skin, and invasion of some of these lesions can produce morbidity. These and other factors affect the choice of the type of procedure used, the timing for intervention, and the approach to intervention in this age group. This article reviews the important considerations for approaching procedures and offers suggestions for safe and effective methods of reliably producing the intended outcome. [source] A rapid technique for assessing the suitability of areas for invasive species applied to New Zealand's riversDIVERSITY AND DISTRIBUTIONS, Issue 2 2008Cathy Kilroy ABSTRACT Early responses to incursions of non-indigenous species (NIS) into new areas include modelling and surveillance to define the organisms' potential and actual distributions. For well-studied invasive species, predictive models can be developed based on quantitative data describing environmental tolerances. In late 2004, an invasive freshwater diatom Didymosphenia geminata, an NIS for which we had no such quantitative data, was detected in a New Zealand river. We describe a procedure used to rapidly develop a classification of suitability for all New Zealand's rivers, based on two sources of information. First, from a review of the limited available literature and unpublished data, we determined that temperature, hydrological and substrate stability, light availability, and water pH were the most important environmental gradients determining D. geminata's broad-scale distribution and capacity for establishing and forming blooms in rivers. The second information source was a GIS-based river network developed for a national classification of New Zealand's rivers, with associated data describing environmental characteristics of each section of the network. We used six variables that were available for every section of the network as surrogates for the environmental gradients that determine suitability. We then determined the environmental distance of all the river sections in the network from our assessment of the optimal conditions conducive to D. geminata blooms. The analysis suggested that > 70% of New Zealand's river sections (stream order > 3) fell into the two highest suitability categories (on a five-point scale). At the time of writing, D. geminata had spread to 12 catchments, all of which were within these two categories. The technique is applicable in initial responses to incursions of NIS where quantitative information is limited, and makes optimal use of available qualitative information. Our assessment contributed to evaluations of the potential ecological, social, and economic impacts of D. geminata and is currently being used to stratify site selection for ongoing surveillance. [source] Technical basis for narcotic chemicals and polycyclic aromatic hydrocarbon criteria.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2000Abstract A method is presented for developing water quality criteria (WQC) for type I narcotic chemicals in general and PAHs in particular. The criteria can be applied to any individual or mixture of narcotic chemicals using only the chemical's octanol-water partition coefficient KOW. It is derived from a database of LC50s comprising 156 chemicals and 33 species, including fish, amphibians, arthropods, mollusks, polychaetes, coelenterates, and protozoans. A target lipid model is proposed that accounts for variations in toxicity due to differing species sensitivities and chemical differences. The model is based on the idea that a target lipid is the site of action in the organism. Further, it is assumed that target lipid has the same lipid-octanol linear free energy relationship for all species. This implies that the slope of the log(LC50),log(KOW) relationship is the same for all species. However, individual species may have varying target lipid body burdens that cause toxicity. The target lipid LC50 body burdens derived from concentration data in the water only are compared to measured total lipid LC50 body burdens for five species. They are essentially equal, indicating that the target lipid concentration is equal to the total extracted lipid concentration. The precise relationship between partitioning in target lipid and octanol is established. The species-specific body burdens are used to determine the WQC final acute value, i.e., the 95-percentile level of protection. An acute-to-chronic ratio is used to compute the body burden corresponding to the WQC final chronic value, which is the procedure used to derive the U.S. Environmental Protection Agency water quality criteria. The criteria are expressed either as dissolved concentrations in the water column or as tissue concentrations. [source] Treatment of the N0 neck during salvage surgery after radiotherapy of head and neck squamous cell carcinomaHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2005Stephane Temam MD Abstract Background. The morbidity and mortality rates of salvage surgery in patients with local recurrence of head and neck squamous cell carcinoma (HNSCC) after radiotherapy are high. The aim of this study was to determine the rate of occult neck node metastasis and the surgical morbidity of patients after salvage surgery for local relapse after definitive radiotherapy. Methods. Thirty patients who underwent salvage surgery with a simultaneous neck node dissection for a local relapse after definitive radiotherapy for HNSCC between 1992 and 2000 were included in this study. The primary tumor sites were oral cavity in six patients, oropharynx in 17, supraglottic larynx in three, and hypopharynx in four. Initially, seven patients had T2 disease, eight had T3, and 15 had T4. Results. Twelve patients (40%) experienced postoperative complications, including two deaths. There was no cervical lymph node metastasis (pN0) in 29 of the 30 patients. Fifteen patients (50%) had a recurrence after salvage surgery, including 11 new local recurrences and four patients with distant metastasis. Conclusions. The risk of neck node metastasis during salvage surgery for local recurrence in patients treated initially with radiation for N0 HNSCC is low. Neck dissection should be performed in only limited area, depending on the surgical procedure used for tumor resection. © 2005 Wiley Periodicals, Inc. Head Neck27: XXX,XXX, 2005 [source] Annual streamflow modelling with asymmetric distribution functionHYDROLOGICAL PROCESSES, Issue 17 2008Nermin Sarlak Abstract Classical autoregressive models (AR) have been used for forecasting streamflow data in spite of restrictive assumptions, such as the normality assumption for innovations. The main reason for making this assumption is the difficulties faced in finding model parameters for non-normal distribution functions. However, the modified maximum likelihood (MML) procedure used for estimating autoregressive model parameters assumes a non-normally distributed residual series. The aim in this study is to compare the performance of the AR(1) model with asymmetric innovations with that of the classical autoregressive model for hydrological annual data. The models considered are applied to annual streamflow data obtained from two streamflow gauging stations in K,z,l,rmak Basin, Turkey. Copyright © 2008 John Wiley & Sons, Ltd. [source] Grid-based density functional calculations of many-electron systemsINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 5 2008Amlan K. RoyArticle first published online: 10 DEC 200 Abstract Exploratory variational pseudopotential density functional calculations are performed for the electronic properties of many-electron systems in the 3D cartesian coordinate grid (CCG). The atom-centered localized gaussian basis set, electronic density, and the two-body potentials are set up in the 3D cubic box. The classical Hartree potential is calculated accurately and efficiently through a Fourier convolution technique. As a first step, simple local density functionals of homogeneous electron gas are used for the exchange-correlation potential, while Hay-Wadt-type effective core potentials are employed to eliminate the core electrons. No auxiliary basis set is invoked. Preliminary illustrative calculations on total energies, individual energy components, eigenvalues, potential energy curves, ionization energies, and atomization energies of a set of 12 molecules show excellent agreement with the corresponding reference values of atom-centered grid as well as the grid-free calculation. Results for three atoms are also given. Combination of CCG and the convolution procedure used for classical Coulomb potential can provide reasonably accurate and reliable results for many-electron systems. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 [source] Atrial Size Reduction as a Predictor of the Success of Radiofrequency Maze Procedure for Chronic Atrial Fibrillation in Patients Undergoing Concomitant Valvular SurgeryJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2001MIEN-CHENG CHEN M.D. Radiofrequency Maze Procedure and Atrial Size.Introduction: Previous studies showed that the surgical maze procedure can restore sinus rhythm and atrial transport function in patients with chronic atrial fibrillation (AF). However, no previous studies discussed the association of atrial size reduction and the success of sinus conversion by the radiofrequency (RF) maze procedure for chronic AF. Methods and Results: A total of 119 chronic AF patients undergoing valvular operations were included in this study. Sixty-one patients received RF and cryoablation to create lesions in both atria to simulate the surgical maze II or III procedure (RF maze II or RF maze III; 13 patients, group 1) or a modified maze pattern (RF maze "IV"; 48 patients, group 2). The other 58 patients who underwent valvular operations alone without the maze procedure served as control (group 3). At 3-month follow-up after operation, sinus rhythm was restored in 73%, 81%, and 11% of patients in groups 1, 2 and 3, respectively. Preoperative left and right atrial sizes were not statistically significant predictors of sinus conversion by the RF maze procedure. However, as a result of postoperative reduction of atrial sizes, postoperative left atrial diameter was significantly smaller in patients who had sinus conversion by the RF maze procedure than in patients who did not regain sinus rhythm (45.0 ± 7.0 mm vs 51.0 ± 8.0 mm; P = 0.03). Postoperative right atrial area of patients who had sinus conversion by the RF maze procedure also was significantly smaller than that of patients who did not regain sinus rhythm (18.1 ± 4.4 cm2 vs 28.5 ± 8.2 cm2; P = 0.008). Conclusion: Atrial size reduction appears to predict the success of sinus conversion with the RF maze procedure used in conjunction with valvular surgery. [source] Olive oil mill waste water as a replacement for fresh water in the manufacture of fired clay bricksJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2006Houda Mekki Abstract This paper describes the introduction of olive mill wastewater (OMW) to replace fresh water normally used in clay brick manufacture. OMW is recognised as the major agro-food industry pollutant in the Mediterranean/North African olive-growing region. The research involved adding OMW to laboratory-produced clay bricks following the same making procedure used at a collaborating Tunisian brick factory. The samples containing OMW were found to be comparable in forming/extrusion performance to a control product that used fresh water. If introduced at the factory scale, this innovation would allow a substantial volume of OMW to be recycled, saving on the fresh water currently used in the brick-forming process. During the subsequent brick drying operation, most of the OMW (,98% water) would be released as vapour. Once in the kiln, the remaining solids in the bricks (calorific value 21,23 MJ kg,1) would liberate additional heat, reducing the gross energy from fossil fuel currently required during firing. Copyright © 2006 Society of Chemical Industry [source] Bias-free results in the spectrophotometric determination of chemical oxygen demand in bleached textile mill effluentsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2002Francesc Torrades Abstract A calibration methodology that enables validation of the analytical procedure used in those cases where no placebo or standard reference material is available is applied here. The total Youden blank is used to eliminate the constant error component, and analytical measurements in the presence of the matrix at two different levels of the test portion, in order to avoid its interactive interference, are made. Moreover, the results obtained in the determination of chemical oxygen demand following a closed reflux spectrophotometric method are compared with those obtained when a definitive analytical method is applied, in order to show the absence of direct interference from the matrix. © 2002 Society of Chemical Industry [source] FLOW ANALYSIS OF LANDSLIDE DAMMED LAKE WATERSHEDS: A CASE STUDY1JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 6 2006Kwan Tun Lee Abstract: The Chi-Chi earthquake, which occurred on September 21, 1999, and had a magnitude of 7.3 on the Richter scale, resulted in an extensive landslide that blocked the Ching-Shui Creek in Taiwan, forming a large lake with a storage volume of 40 million m3. This paper describes an analytical procedure used to perform flow analysis of the Tsao-Ling watershed, which includes the new landslide dammed lake. In this study, a digital elevation model was applied to obtain the watershed geomorphic factors and stage-area storage function of the landslide dammed lake. Satellite images were used to identify the landslide area and the land cover change that occurred as a result of the earthquake. Two topography-based runoff models were applied for long term and short term streamflow analyses of the watershed because the watershed upstream of the landslide dam was ungauged. The simulated daily flow and storm runoff were verified using limited available measured data in the watershed, and good agreement was obtained. The proposed analytical procedure for flow analysis is considered promising for application to other landslide dammed lake watersheds. [source] Genetic analysis of functions involved in the late stages of biofilm development in Burkholderia cepacia H111MOLECULAR MICROBIOLOGY, Issue 2 2002Birgit Huber Summary Burkholderia cepacia and Pseudomonas aeruginosa often co-exist as mixed biofilms in the lungs of patients suffering from cystic fibrosis (CF). Here, we report the isolation of 13 random mini-Tn 5 insertion mutants of B. cepacia H111 that are defective in biofilm formation on a polystyrene surface. We show that the screening procedure used in this study is biased towards mutants defective in the late stages of biofilm development. A detailed quantitative analysis of the biofilm structures formed by wild-type and mutant strains revealed that the isolated mutants are impaired in their abilities to develop a typical three-dimensional biofilm structure. Molecular investigations showed that the genes required for biofilm maturation fall into several classes: (i) genes encoding for surface proteins; (ii) genes involved in the biogenesis and maintenance of an integral outer membrane; and (iii) genes encoding regulatory factors. It is shown that three of the regulatory mutants produce greatly reduced amounts of N -octanoylhomoserine lactone (C8-HSL). This compound serves as the major signal molecule of the cep quorum-sensing system. As this density-dependent regulatory system is involved in the regulation of biofilm maturation, we investigated the interplay between the three regulatory genes and the quorum-sensing cascade. The results of these investigations show that the identified genes encode for regulatory elements that are positioned upstream of the cep system, indicating that the quorum-sensing system of B. cepacia is a major checkpoint for biofilm formation. [source] Optical super-resolution using higher harmonics and different acquisition modes in an aperture tapping SNOMPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 8 2010Giovanni Longo Abstract Scanning near field optical microscopy (SNOM) is a well-established technique to obtain a sub-wavelength resolution optical characterization, together with nanometer-scale topography images, on any kind of biological or non-biological sample. Recently we have modified a classical SNOM unit to work in the tapping modality, ensuring stability, versatility and good optical resolution and signal to noise ratio. Exploiting the vertical tip movement, in particular, we were able to access two different optical detection modes: light modulation, which can be obtained by a mechanical chopper or by electronically switching the laser on and off; gap modulation in which the tip's vertical oscillation is used to produce, itself, a modulation of the collected light. Several biological and non-biological samples have been investigated and the data reveal that, despite the signal collected in gap-modulation is at least one order of magnitude smaller than in laser-modulation, resolution, and signal-to-noise ratio in the gap-modulated images is preferable. On the other hand, the higher intensity of the laser-modulation signal allows to deconvolve the optical information at higher harmonics of the tip oscillation frequency. This is a well-known procedure used in the apertureless-SNOM setup to enhance the near-field contribution of the scattered light and reduce the noise content. The interesting results obtained in this Aperture setup are described and commented. [source] Long-term performance of environmentally-friendly blown polyurethane foamsPOLYMER ENGINEERING & SCIENCE, Issue 3 2005M. Modesti We studied the long-term performance of new environmentally-friendly blowing agents for polyurethane foams. Several blowing agents, hydrofluorocarbons, hydrocarbons, and a possible hydrochlorofluorocarbon substitute (dimethoxymethane), as well as hydrochlorofluorocarbons, were analyzed. The determination of effective diffusion coefficients (knowledge of which is required to study long-term performance) was performed by means of a classical gas chromatographic technique and by a new method based on infrared spectroscopy. The reliability of the experimental procedure used is showed by comparing experimental and predicted aging, as the slope of the aging curve (i.e., thermal conductivity vs. time) depends only on effective diffusion coefficients. Our study of long-term performance of foams blown with alternative blowing agents shows that hydrofluorocarbons represent a proper alternative to hydrochlorofluorocarbons, as the foams show similar initial thermal conductivity and a slower aging rate (i.e., better long-term performance). POLYM. ENG. SCI. 45:260,270, 2005. © 2005 Society of Plastics Engineers. [source] Memory-based or afferent processes in mismatch negativity (MMN): A review of the evidencePSYCHOPHYSIOLOGY, Issue 1 2005Risto Näätänen Abstract The mismatch negativity (MMN) is an electromagnetic response to any discriminable change in regular auditory input. This response is usually interpreted as being generated by an automatic cortical change-detection process in which a difference is found between the current input and the representation of the regular aspects of the preceding auditory input. Recently, this interpretation was questioned by Jääskeläinen et al. (2004) who proposed that the MMN is a product of an N1 (N1a) difference wave emerging in the subtraction procedure used to visualize and quantify the MMN. We now evaluate this "adaptation hypothesis" of the MMN in the light of the available data. It is shown that the MMN cannot be accounted for by differential activation of the afferent N1 transient detectors by repetitive ("standard") stimuli and deviant ("novel") stimuli and that the presence of a memory representation of the standard is required for the elicitation of MMN. [source] Comparison of two new approaches to variable ordering for binary decision diagramsQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 3 2001L. M. Bartlett Abstract Fault tree analysis, FTA, is one of the most commonly used techniques for safety system analysis. There can be problems with the efficiency and accuracy of the approach when dealing with large tree structures. Recently the binary decision diagram (BDD) methodology has been introduced which significantly aids the analysis of the fault tree diagram. The approach has been shown to improve both the efficiency of determining the minimal cut sets of the fault tree, and also the accuracy of the calculation procedure used to quantify the top event parameters. To utilize the BDD technique the fault tree structure needs to be converted into the BDD format. Converting the fault tree is relatively straightforward but requires the basic events of the tree to be placed in an ordering. The ordering of the basic events is critical to the resulting size of the BDD, and ultimately affects the performance and benefits of this technique. There are a number of variable ordering heuristics in the literature, however the performance of each depends on the tree structure being analysed. These heuristic approaches do not yield a minimal BDD structure for all trees, some approaches generate orderings that are better for some trees but worse for others. Within this paper two approaches to the variable ordering problem have been discussed. The first is the pattern recognition approach of neural networks, which is used to select the best ordering heuristic for a given fault tree from a set of alternatives. The second examines a completely new heuristic approach of using the structural importance of a component to produce a ranked ordering. The merits of each are discussed and the results compared. Copyright © 2001 John Wiley & Sons, Ltd. [source] Implications of enzymatic, acidic and thermal hydrolysis of DNA on the occurrence of cross-linked melphalan DNA adductsRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 4 2005Bart Van den Driessche Calf thymus DNA was treated with melphalan, a nitrogen mustard, and the formation of melphalan cross-linked DNA adducts was investigated. These cross-linked adducts could not be detected either in the enzymatically or in the thermally generated DNA hydrolysates. However, a search for DNA cross-linked adducts in the hydrolysates obtained under acidic conditions revealed the presence of different types of cross-links, mainly containing an adenine moiety. These results are very important because they show that the detection of cross-links is dependent on the hydrolytic procedure used and that these cross-linked adducts are formed under totally different reaction conditions from those in in vivo situations. This can explain the very low abundance or even the absence of cross-linked adducts in nitrogen mustard treated animals. The generally accepted theory that the anti-cancer activity of bifunctional mustards such as melphalan is due to cross-linking of DNA strands remains therefore from our point of view questionable. Copyright © 2005 John Wiley & Sons, Ltd. [source] Changing patterns in interventional bronchoscopyRESPIROLOGY, Issue 4 2009Nikolaos ZIAS ABSTRACT Background and objective: Many interventional tools for airway disorders can now be delivered via flexible bronchoscopy (FB), including neodymium-yttrium aluminium garnet laser, electrocautery, argon plasma coagulation, cryotherapy, balloon dilatation and metal or hybrid stents. Comparison of outcomes for patients undergoing rigid bronchoscopy (RB) with those treated using FB highlights the usefulness of the FB approach. Methods: A retrospective medical record review of all interventional bronchoscopy procedures performed at Lahey Clinic over the past 8 years was conducted. Patients were categorized into two groups according to the procedure used, that is, RB (251 patients), and FB (161 patients) groups. Patients with malignancies were included as a separate subgroup, comprising 178 RB and 117 FB patients. For every procedure, the location of the lesion, patient survival from the first interventional procedure performed, and in patients with malignancy, additional treatments received such as chemotherapy and radiation were recorded. Results: Ninety per cent of RB procedures were performed in patients with tracheal or main stem lesions, while over half the patients undergoing FB had more distal lesions. A trend towards increasing use of FB for interventional procedures in recent years was noted. Conclusions: FB is a valuable alternative to RB for treating less advanced malignant disease or distal airway lesions. [source] Requesting a commitment to change: Conditions that produce behavioral or attitudinal commitmentTHE JOURNAL OF CONTINUING EDUCATION IN THE HEALTH PROFESSIONS, Issue 2 2008Githa Kanisin Overton PhD Abstract There is a lack of clarity in the conceptualization of commitment underlying the commitment to change (CTC) procedure used by organizers of continuing education in the health professions. This article highlights the two distinct conceptualizations of commitment that have emerged in the literature outside health care education and practice. The distinction is important because different antecedent conditions produce different types and dimensions of commitment. This article goes on to explore the antecedents of behavioral and attitudinal commitment and illustrates how different types of commitment may have been produced in previous CTC studies. As a result, the article also demonstrates the need for clarity in the conceptualization of commitment, especially to guide empirical research into the nature and strength of commitment produced by the variety of CTC strategies. Such research is relevant in increasing our understanding of how and why CTCs are able to influence practice change. [source] Persistence of volatility in futures marketsTHE JOURNAL OF FUTURES MARKETS, Issue 6 2006Zhiyao Chen This article examines the characteristics of key measures of volatility for different types of futures contracts to provide a better foundation for modeling volatility behavior and derivative values. Particular attention is focused on analyzing how different measures of volatility affect volatility persistence relationships. Intraday realized measures of volatility are found to be more persistent than daily measures, the type of GARCH procedure used for conditional volatility analysis is critical, and realized volatility persistence is not coherent with conditional volatility persistence. Specifically, although there is a good fit between the realized and conditional volatilities, no coherence exists between their degrees of persistence, a counterintuitive finding that shows realized and conditional volatility measures are not a substitute for one another. © 2006 Wiley Periodicals, Inc. Jrl Fut Mark 26:571,594, 2006 [source] Right hemicolectomy does not confer a survival advantage in patients with mucinous carcinoma of the appendix and peritoneal seedingBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 3 2004S. González-Moreno Background: Traditionally epithelial malignancies of the appendix with or without carcinomatosis have been treated by right hemicolectomy. Recent accumulation of a large number of patients with this disease has enabled a re-evaluation of this surgical judgement. Methods: Clinical data on 501 patients with epithelial malignancy of the appendix were collected prospectively. All patients had peritoneal seeding at the time of referral and were treated by cytoreductive surgery and perioperative intraperitoneal chemotherapy. The main independent variable for statistical analysis was the surgical procedure used to resect the primary cancer (appendicectomy alone versus right hemicolectomy). Nineteen other clinical and pathological variables were considered as control variables. The endpoint for all analyses was survival. Results: Median follow-up after the initial diagnosis was 4 years. The rate of regional lymph node positivity was 5·0 per cent. When the incidence of lymph node metastasis was determined by histological type, it was statistically significantly higher in intestinal (66·7 per cent) than in mucinous (4·2 per cent) tumours (P < 0·001). The presence of lymph node metastases had no influence on prognosis (P = 0·155). The surgical procedure (appendicectomy alone versus right hemicolectomy) had an influence on patient survival by univariate analysis (P < 0·001), but not by multivariate analysis (P = 0·258). Conclusion: Right hemicolectomy does not confer a survival advantage in patients with mucinous appendiceal tumours with peritoneal seeding. These data suggest that right hemicolectomy should be avoided unless metastatic involvement of the appendiceal or distal ileocolic lymph nodes is documented by biopsy, or the resection margin is inadequate. Copyright © 2004 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] Dynamic Modeling and Simulation of Steam Cracking FurnacesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 7 2007M. Ghashghaee Abstract The transient modeling of thermal cracking furnaces is developed. This representation is capable of describing and predicting the unsteady-state behavior of cracking furnaces during start-up. To accurately predict the heat transfer to the reactor tube, the fireside conditions are coupled with the process side. The mutual interaction of these two sections is found to be very stiff in terms of convergence of the computations. The two-dimensional transient zone model is developed for the radiative heat exchange calculation. A simplified model for the convection section is also used to predict the crossover temperature at each time increment. The main simulation outputs are the flue gas properties as well as the distributions of heat flux, refractory wall and coil skin temperatures versus time. The dynamic simulation is implemented for a conventional procedure used in the start-up run of the olefin furnaces. [source] Ridge alterations following tooth extraction with and without flap elevation: an experimental study in the dogCLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2009Mauricio G. Araújo Abstract Background: Different approaches were advocated to preserve or improve the dimension and contour of the ridge following tooth extraction. In some of studies, socket ,flapless extraction' apparently had a successful outcome. Aim: The objective of the present experiment was to compare hard tissue healing following tooth extraction with or without the prior elevation of mucosal full-thickness flaps. Material and methods: Five mongrel dogs were used. The two second mandibular premolars (2P2) were hemi-sected. The mesial roots were retained. By random selection the distal root in one side was removed after the elevation of full-thickness flaps while on the contralateral side, root extraction was performed in a flapless procedure. The soft tissue wound was closed with interrupted sutures. After 6 months of healing, the dogs were euthanized and biopsies were sampled. From each experimental site, four ground sections , two from the mesial root and two from the healed socket , were prepared, stained and examined in the microscope. Results: The data showed that the removal of a single tooth (root) during healing caused a marked change in the edentulous ridge. In the apical and middle portions of the socket site minor dimensional alterations occurred while in the coronal portion of the ridge the reduction of the hard tissue volume was substantial. Similar amounts of hard tissue loss occurred during healing irrespective of the procedure used to remove the tooth was, i.e. flapless or following flap elevation. Conclusion: Tooth loss (extraction) resulted in marked alterations of the ridge. The size of the alveolar process was reduced. The procedure used for tooth extraction , flapless or following flap elevation , apparently did not influence the more long-term outcome of healing. [source] Comparison of three different preparations of platelet concentrates for growth factor enrichmentCLINICAL ORAL IMPLANTS RESEARCH, Issue 5 2002Thorsten R. Appel Abstract: The aim of the present study was to compare three different systems for preparing platelet concentrates: two commercially available bed-side techniques (Curasan system and PCCS) and a procedure used routinely in transfusion medicine. Platelet concentrates were prepared from venous blood of 12 healthy male volunteers using the three different systems. Platelet and leucocyte counts were performed and platelet derived growth factor and transforming growth factor beta were assayed by enzyme linked immunoassay. Handling was also considered. The three systems were able to collect 19.0 ± 16.6% (laboratory system), 41.9 ± 9.7% (Curasan system) and 49.6 ± 21.0% (PCCS) of the absolute number of platelets which were originally in the venous blood volume within the platelet concentrate. Due to the amount of plasma which is left in the platelet concentrate portion, the platelet concentration could be increased between 1.4 ± 1.3 times (laboratory system), 5.0 ± 2.3 times (PCCS) and 11.7 ± 2.4 times (Curasan system) compared to the venous blood. The amount of growth factors correlated with the number of platelets within the platelet concentrates. The two systems for intraoperative use are similar in their effects on the platelets. The absolute gain of platelets seems to be the highest with the PCCS; the highest concentration of platelets per µL is gained with the Curasan system. The laboratory system may offer an alternative if an intraoperative system is not available. [source] Forks in the Road: Choices in Procedures for Designing Wildland LinkagesCONSERVATION BIOLOGY, Issue 4 2008PAUL BEIER análisis de sensibilidad; conectividad; corredor de vida silvestre; enlace; diseño de reservas Abstract:,Models are commonly used to identify lands that will best maintain the ability of wildlife to move between wildland blocks through matrix lands after the remaining matrix has become incompatible with wildlife movement. We offer a roadmap of 16 choices and assumptions that arise in designing linkages to facilitate movement or gene flow of focal species between 2 or more predefined wildland blocks. We recommend designing linkages to serve multiple (rather than one) focal species likely to serve as a collective umbrella for all native species and ecological processes, explicitly acknowledging untested assumptions, and using uncertainty analysis to illustrate potential effects of model uncertainty. Such uncertainty is best displayed to stakeholders as maps of modeled linkages under different assumptions. We also recommend modeling corridor dwellers (species that require more than one generation to move their genes between wildland blocks) differently from passage species (for which an individual can move between wildland blocks within a few weeks). We identify a problem, which we call the subjective translation problem, that arises because the analyst must subjectively decide how to translate measurements of resource selection into resistance. This problem can be overcome by estimating resistance from observations of animal movement, genetic distances, or interpatch movements. There is room for substantial improvement in the procedures used to design linkages robust to climate change and in tools that allow stakeholders to compare an optimal linkage design to alternative designs that minimize costs or achieve other conservation goals. Resumen:,Los modelos son utilizados comúnmente para identificar tierras que mantengan la habilidad de la vida silvestre para moverse entre bloques de tierras silvestres a través de una matriz de tierras que habían sido incompatibles con el movimiento de vida silvestre. Ofrecemos 16 opciones y supuestos que se originan en el diseño de enlaces para facilitar el movimiento o el flujo de genes de especies focales entre 2 o más bloques de tierras silvestres predefinidos. Recomendamos el diseño de enlaces que sirvan a múltiples (y solo a una) especies focales que funjan como una sombrilla colectiva para todas las especies nativas y los procesos ecológicos, que explícitamente admitan supuestos no comprobados y que utilicen análisis de incertidumbre para ilustrar efectos potenciales de la incertidumbre del modelo. La mejor forma de mostrar tal incertidumbre a los interesados es mediante mapas de los enlaces modelados bajo diferentes suposiciones. También recomendamos modelar a habitantes de corredores (especies que requieren más de una generación para mover sus genes entre bloques de tierra silvestre) de manera diferente que las especies pasajeras (un individuo se puede mover entre bloques de tierras silvestres en unas cuantas semanas). Identificamos un problema, que denominamos el problema de traducción subjetiva, que surge porque un analista debe decidir subjetivamente cómo traducir medidas de selección de recursos a resistencia. Este problema puede ser sobrepuesto mediante la estimación de la resistencia a partir de observaciones de movimientos de animales, distancias genéticas o movimientos entre fragmentos. Hay espacio para la mejora sustancial de los procedimientos utilizados para diseñar enlaces robustos ante el cambio climático y en herramientas que permiten que los interesados comparen un diseño óptimo con diseños alternativos que minimicen costos o alcancen otras metas de conservación. [source] Silicone Gel Sheeting for the Management and Prevention of OnychocryptosisDERMATOLOGIC SURGERY, Issue 3 2003A. Burhan Aksakal MD BACKGROUND Onychocryptosis, commonly referred to as ingrown nails, has many therapeutic alternatives for its management. Although mild cases can be treated conservatively, in severe cases, surgical treatment is preferred. Silicone gel sheeting is found to be effective in the treatment of hypertrophic scars and keloids. OBJECTIVE To document the effectiveness of silicone gel sheeting in the management of patients with onychocryptosis and in the prevention of the recurrences by breaking the devil's circle, which usually took place after the surgical procedures used in the treatment of the onychocryptosis. METHODS Fourteen patients were enrolled in the study. Entry criteria required the presence of slight (2 patients), moderate (2 patients), or severe (10 patients) onychocryptosis. The simple technique used in the study was the excision of the one-quarter part of the lesional side of the nail plate without excising the granulation tissue. After 24 hours, the silicone was placed on the granulation tissue and the exposed nail bed. Silicone gel sheet was bandaged loosely without applying any pressure. Patients entering the study were given detailed instructions in applying and using the gel for 12 hours during the daytime. The study lasted for 14 months and was composed of a treatment period of 4 months and a follow-up period of 10 months. The patients were evaluated every 2 weeks in the first month and then monthly. The change in thickness of granulation tissue was evaluated by comparing them with the baseline photographs and those taken at each visit. RESULTS The management and prevention of onychocryptosis were achieved in 12 of 14 patients (85.71%). The silicone gel sheeting treatment was well tolerated except for an occasional transient exudation, which was resolved when the treatment was withdrawn. CONCLUSION The results show that the new method that we used for the treatment of onychocryptosis is successful in reducing the thickness of the hypertrophic nail fold and prevents the recurrence of the condition during the regrowth of the nail plate by breaking the devil's circle. The advantage of this method is that it is not destructive to the nail matrix and the adjacent tissue. [source] Feasibility of using the TOSCA telescreening procedures for diabetic retinopathyDIABETIC MEDICINE, Issue 10 2004S. Luzio Abstract Aims The TOSCA project was set up to establish a tele-ophthalmology service to screen for diabetic retinopathy (DR) in Europe. The aim of this study was to determine the feasibility of establishing telemedicine-based digital screening for detecting DR and to evaluate the satisfaction of both patients and healthcare professionals with the screening procedures used within the TOSCA project. Methods The study was a non-randomized, multicentre study carried out in four different countries over a period of 3 months. Patients (n = 390) with diabetes aged > 12 years were included. Two digital retinal images per eye (macular and nasal) were taken and exported to a central server. Patients were asked to complete a questionnaire to assess satisfaction. Accredited graders carried out grading remotely and the results were reported back to the referring centre. Previously graded patient data chosen randomly to represent examples of both DR and no DR were also sent anonymously to the grading centre at a frequency of approximately every 10 patients. Results Most (99%) of the images were assessable enabling a retinopathy grade to be assigned to the patient. Patients found the retinal photography procedures acceptable; only 6% in one centre would not recommend the procedure. Healthcare professionals (photographers and graders) were also satisfied with the overall procedures. The average time taken to grade each patient was approximately 5 min. Conclusions This study demonstrated that it is feasible to electronically transmit and grade retinal images remotely using the TOSCA process. Built-in quality assurance procedures proved acceptable. [source] The Current Usage of Selectivity Coefficients for the Characterization of Ion-Selective Electrodes.ELECTROANALYSIS, Issue 12 2003A Critical Survey of the 2000/2001 Literature Abstract The articles describing new ion-selective electrodes published during the years 2000/2001 in eight leading analytical chemistry journals have been surveyed. Compliance with the IUPAC recommendations of the procedures used for characterizing the selectivity of the new electrodes has been checked. It was found that the information accompanying the selectivity data obtained according to the procedures recommended by IUPAC or their variations was frequently insufficient for interpreting of the electrode behavior and comparing with other sets of data, thus reducing the significance of the values provided. Some criteria for improving the communication between researchers in the field are suggested. [source] Cytochrome b559 content in isolated photosystem II reaction center preparationsFEBS JOURNAL, Issue 10 2003Inmaculada Yruela The cytochrome b559 content was examined in five types of isolated photosystem II D1-D2-cytochrome b559 reaction center preparations containing either five or six chlorophylls per reaction center. The reaction center complexes were obtained following isolation procedures that differed in chromatographic column material, washing buffer composition and detergent concentration. Two different types of cytochrome b559 assays were performed. The absolute heme content in each preparation was obtained using the oxidized-minus-reduced difference extinction coefficient of cytochrome b559 at 559 nm. The relative amount of D1 and cytochrome b559,-subunit polypeptide was also calculated for each preparation from immunoblots obtained using antibodies raised against the two polypeptides. The results indicate that the cytochrome b559 heme content in photosystem II reaction center complexes can vary with the isolation procedure, but the variation of the cytochrome b559,-subunit/D1 polypeptide ratio was even greater. This variation was not found in the PSII-enriched membrane fragments used as the RC-isolation starting material, as different batches of membranes obtained from spinach harvested at different seasons of the year or those from sugar beets grown in a chamber under controlled environmental conditions lack variation in their ,-subunit/D1 polypeptide ratio. A precise determination of the ratio using an RC1-control sample calibration curve gave a ratio of 1.25 cytochrome b559,-subunit per 1.0 D1 polypeptide in photosystem II membranes. We conclude that the variations found in the reaction center preparations were due to the different procedures used to isolate and purify the different reaction center complexes. [source] | ||||||||||||||||||||||||||||||||||||||||