bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental transmission of atypical scrapie to sheep
Authors: Simmons Marion M , Konold Timm , Simmons Hugh A , Spencer Yvonne I , Lockey Richard , Spiropoulos John , Everitt Sharon , Clifford Derek
Published: August 2007

Background

Active surveillance for transmissible spongiform encephalopathies in small ruminants has been an EU regulatory requirement since 2002. A number of European countries have subsequently reported cases of atypical scrapie, similar to previously published cases from Norway, which have pathological and molecular features distinct from classical scrapie. Most cases have occurred singly in flocks, associated with genotypes considered to be more resistant to classical disease. Experimental transmissibility of such isolates has been reported in certain ovinised transgenic mice, but has not previously been reported in the natural host. Information on the transmissibility of this agent is vital to ensuring that disease control measures are effective and proportionate.

Results

This report presents the successful experimental transmission, in 378 days, of atypical scrapie to a recipient sheep of homologous genotype with preservation of the pathological and molecular characteristics of the donor. This isolate also transmitted to ovinised transgenic mice (Tg338) with a murine phenotype indistinguishable from that of Nor 98.

Conclusion

This result strengthens the opinion that these cases result from a distinct strain of scrapie agent, which is potentially transmissible in the natural host under field conditions.
Usefulness of open lung biopsy in mechanically ventilated patients with undiagnosed diffuse pulmonary infiltrates: influence of comorbidities and organ dysfunction
Authors: Lim Seong Yong , Suh Gee Young , Choi Jae Chol , Koh Won Jung , Lim Si Young , Han Joungho , Lee Kyung Soo , Shim Young Mog , Chung Man Pyo , Kim Hojoong , Kwon O Jung
Published: August 2007

Background

The purpose of this study was to evaluate the clinical usefulness of open lung biopsy (OLB) in patients undergoing mechanical ventilation for diffuse pulmonary infiltrates of unknown etiology.

Methods

This was a 10-year retrospective study in a 10-bed medical intensive care unit. The medical records of 36 ventilator-dependent patients who underwent OLB for the diagnosis of unknown pulmonary infiltrates from 1994 to 2004 were reviewed retrospectively. Data analyzed included demographic data, Charlson age–comorbidity score, number of organ dysfunctions, Acute Physiology and Chronic Health Evaluation (APACHE) II, Simplified Acute Physiology Score (SAPS) II, Sequential Organ Failure Assessment (SOFA) score, ventilation variables, and radiological patterns. Diagnostic yield, effect on subsequent treatment changes, and complications of OLB were also assessed.

Results

A specific clinico-pathologic diagnosis was obtained for 31 patients (86%). The most common diagnoses were interstitial pneumonia (n = 17, including 8 acute interstitial pneumonia) and viral pneumonia (n = 4). Therapeutic modifications were made in 64% of patients. Patients who received OLB less than 1 week after initiation of mechanical ventilation were more likely to survive (63% versus 11%; P = 0.018). There were no major complications associated with the procedure. Factors independently associated with survival were the Charlson age-comorbidity score, number of organ dysfunction and the PaO2/FiO2 ratio on the day of the OLB.

Conclusion

OLB can provide a specific diagnosis in many ventilator-dependent patients with undiagnosed pulmonary infiltrate. Early OLB seems to be useful in critically ill patients with isolated respiratory failure.
Comorbidity and Disease Status–Based Risk Stratification of Outcomes Among Patients With Acute Myeloid Leukemia or Myelodysplasia Receiving Allogeneic Hematopoietic Cell Transplantation
Authors: Sorror Mohamed L. , Sandmaier Brenda M. , Storer Barry E. , Maris Michael B. , Baron Frédéric , Maloney David G. , Scott Bart L. , Deeg H. Joachim , Appelbaum Frederick R. , Storb Rainer
Published: August 2007

Purpose

Retrospective studies have shown similar survival among patients with acute myeloid leukemia (AML) and myelodysplasia (MDS) after nonmyeloablative compared with myeloablative conditioning. Refined risk stratification is required to design prospective trials.

Patients and Methods

We stratified outcomes among patients with AML (n = 391) or MDS (n = 186) who received either nonmyeloablative (n = 125) or myeloablative (n = 452) allogeneic hematopoietic cell transplantation (HCT) based on comorbidities, as assessed by a HCT-specific comorbidity index (HCT-CI), as well as disease status. Patients receiving nonmyeloablative conditioning were older, more frequently pretreated, more often received unrelated grafts, and more often had HCT-CI scores of ≥ 3 compared with patients who received myeloablative conditioning.

Results

Patients with HCT-CI scores of 0 to 2 and either low or high disease risks had probabilities of overall survival at 2 years of 70% and 57% after nonmyeloablative conditioning compared with 78% and 50% after myeloablative conditioning, respectively. Patients with HCT-CI scores of ≥ 3 and either low or high disease risks had probabilities of overall survival of 41% and 29% with nonmyeloablative conditioning compared with 45% and 24% with myeloablative regimens, respectively. After adjusting for pretransplantation differences, stratified outcomes were not significantly different among patients receiving nonmyeloablative compared with myeloablative conditioning, with the exception of lessened nonrelapse mortality (hazard ratio, 0.50; P = .05) in the highest risk group.

Conclusion

Patients with low comorbidity scores could be candidates for prospective randomized trials comparing nonmyeloablative and myeloablative conditioning regardless of disease status. Additional data are required for patients with low-risk diseases and high comorbidity scores. Novel antitumor agents combined with nonmyeloablative HCT should be explored among patients with high comorbidity scores and advanced disease.
Electroactive polymers as an enabling materials technology
Authors: Bar-Cohen Y
Published: August 2007

Natural muscles are the actuators in most of the biological systems that are larger than a bacterium. The drive mechanism of muscles is complex, and they are capable of lifting large loads with short time response in the range of milliseconds. Electroactive polymers (EAPs) are human-made actuators that most closely emulate biological muscles, and therefore they earned the moniker ‘artificial muscles’. Initially, EAPs received relatively little attention because of their limited actuation capability. In the last 15 years, a series of EAP materials have emerged that exhibit a significant shape change in response to electrical stimulation. Using these materials as actuators, various novel mechanisms and devices were already demonstrated, including robot fish, catheter steering element, miniature gripper, loudspeaker, active diaphragm, and dust wiper. The impressive advances in improving their actuation strain capability are attracting the attention of engineers and scientists from many different disciplines. These materials are particularly attractive to biomimetic applications, because they can be used to make biologically inspired intelligent robots and other mechanisms. Increasingly, engineers are able to develop EAP-actuated mechanisms that were previously considered science fiction. This article reviews the state-of-the-art challenges and potential applications of EAP materials.
Damage detection in composites using optical fibre sensors
Authors: Takeda N , Okabe Y , Mizutani T
Published: August 2007

Optical fibre sensors (OFSs) are promising as tools for damage and structural health monitoring (SHM) of aerospace composite structures. Hence, many researchers have conceived various kinds of OFSs. First, a brief summary of OFSs used for composites is presented. Then, the authors' studies on the small-diameter fibre Bragg grating (FBG) sensors for damage monitoring and SHM of composite structures are described. The authors and Hitachi Cable, Ltd have developed a small-diameter optical fibre and its FBG sensor for embedment inside a lamina of composite laminates without strength reduction. Then, some recent results in the current Structural Integrity Diagnosis and Evaluation of Advanced Composite Structures (ACS-SIDE) project are presented on optical fibre-based SHM for some feasible applications in aerospace composite structures.
Dielectric non-destructive testing approach to cure monitoring of adhesives and composites
Authors: Garden L H , Hayward D , Pethrick R A
Published: August 2007

In the fabrication of many composite and adhesively bonded structures it is desirable to determine the extent to which complete cure is achieved. This review briefly discusses the fundamental issues which are involved in the monitoring of the cure process in thermoset resins. The application of the dielectric method is described as a non-destructive probe for the monitor of the cure process in thermoset resin systems. The principles of the technique are illustrated with reference to a simple epoxy-amine structural adhesive. Possible correlations between the changes in the dielectric properties with other physical property changes of a resin, e.g. viscosity, during cure are discussed.
Self-healing: A new paradigm in materials design
Authors: Kessler M R
Published: August 2007

Self-healing materials, when damaged, are designed to sense the failure and respond in an autonomous fashion to restore structural function. Inspired by biological systems, synthetic self-healing materials represent a new paradigm in the design of polymer based composites. This overview article summarizes the different strategies and approaches to achieving self-healing functionality and discusses future directions in the nascent field. The strategies are broadly classified into the following three categories: healing with an embedded liquid phase repair agent, thermally activated solid phase healing, and healing of projectile puncture.
Damage detection using self-sensing concepts
Authors: Chung D D L
Published: August 2007

Self-sensing refers to the structural material sensing itself. Real-time self-sensing of damage in carbon fibre polymer-matrix composites by electrical resistance measurement is reviewed. The resistance changes irreversibly upon damage, as shown for damage inflicted by flexure, tension, fatigue, and impact. Delamination increases the through-thickness resistance. Fibre breakage increases the longitudinal resistance. The oblique resistance, as measured at an angle between the longitudinal and through-thickness directions, is particularly sensitive. Minor flexural damage causes the oblique resistance in the unloaded state to decrease. Current spreading enables the sensing of localized damage by measurement away from the damage, though it reduces the spatial resolution of the sensing. The resistance method is more sensitive than the potential method. Two-dimensional sensing is complicated by the anisotropic spreading of the current. Thermal damage and through-thickness (fastening) compression effect are indicated by the contact resistivity of the interlaminar interface. The through-thickness compression effect is alternately indicated by the longitudinal volume resistivity. The condition of a composite fastening joint is indicated by the contact resistivity of the joint interface.
A Case Study of Joint Online Truck Scheduling and Inventory Management for Multiple Warehouses
Authors: Helmberg C. , Röhl S.
Published: August 2007

For a real-world problem—transporting pallets between warehouses to guarantee sufficient supply for known and additional stochastic demand—we propose a solution approach via convex relaxation of an integer programming formulation, suitable for online optimization. The essential new element linking routing and inventory management is a convex piecewise-linear cost function that is based on minimizing the expected number of pallets that still need transportation. For speed, the convex relaxation is solved approximately by a bundle approach yielding an online schedule in five to 12 minutes for up to three warehouses and 40,000 articles; in contrast, computation times of state-of-the-art LP solvers are prohibitive for online application. In extensive numerical experiments on a real-world data stream, the approximate solutions exhibit negligible loss in quality; in long-term simulations the proposed method reduces the average number of pallets needing transportation due to short-term demand to less than half the number observed in the data stream.
Forecast Horizons for a Class of Dynamic Lot-Size Problems Under Discrete Future Demand
Authors: Dawande Milind , Gavirneni Srinagesh , Naranpanawe Sanjeewa , Sethi Suresh
Published: August 2007

We present structural and computational investigations of a new class of weak forecast horizons—minimal forecast horizons under the assumption that future demands are integer multiples of a given positive real number—for a specific class of dynamic lot-size (DLS) problems. Apart from being appropriate in most practical instances, the discreteness assumption offers a significant reduction in the length of a minimal forecast horizon over the one using the classical notion of continuous future demands. We provide several conditions under which a discrete-demand forecast horizon is also a continuous-demand forecast horizon. We also show that the increase in the cost resulting from using a discrete minimal forecast horizon instead of the classical minimal forecast horizon is modest. The discreteness assumption allows us to characterize forecast horizons as feasibility/optimality questions in 0-1 mixed-integer programs. On an extensive test bed, we demonstrate the computational tractability of the integer programming approach. Owing to its prevalence in practice, our computational experiments emphasize the special case of integer future demands.
A Decentralized Approach to Discrete Optimization via Simulation: Application to Network Flow
Authors: Garcia Alfredo , Patek Stephen D. , Sinha Kaushik
Published: August 2007

We study a new class of decentralized algorithms for discrete optimization via simulation, which is inspired by the fictitious play algorithm applied to games with identical interests. In this approach, each component of the solution vector of the optimization model is artificially assumed to have a corresponding “player,” and the interaction of these players in simulation allows for exploration of the solution space and, for some problems, ultimately results in the identification of the optimal solution. Our algorithms also allow for correlation in players’ decision making, a key feature when simulation output is shared by multiple decision makers. We first establish convergence under finite sampling to equilibrium solutions. In addition, in the context of discrete network flow models, we prove that if the underlying link cost functions are convex, then our algorithms converge almost surely to an optimal solution.
Performance Prediction and Preselection for Optimization and Heuristic Solution Procedures
Authors: Hall Nicholas G. , Posner Marc E.
Published: August 2007

The operations research literature contains numerous studies on the design and application of optimization and heuristic solution procedures. These studies identify a particular optimization problem, suggest a general solution procedure, and then customize that procedure to improve its efficiency and/or accuracy. In contrast, this paper shows how to use existing solution procedures more effectively. We develop a methodology for predicting the relative performance of alternative procedures, using easily computed problem characteristics. This methodology enables us, for any given data set, to preselect a solution procedure. We apply this preselection methodology to the 0-1 knapsack problem for which two successful optimization procedures, dynamic programming and branch-and-search, are available. Extensive computational testing indicates that substantial savings in average computation time are achieved. The benefits of our work include faster and cheaper identification of effective solution procedures, as well as an improved understanding of the relationship between problem characteristics and the performance of various procedures. Our methodology can be applied to many optimization problems to develop easily implemented guidelines for selecting appropriate solution procedures.
Building Efficient Product Portfolios at John Deere and Company
Authors: Yunes Tallys H. , Napolitano Dominic , Scheller-Wolf Alan , Tayur Sridhar
Published: August 2007

John Deere & Company (Deere), one of the world’s leading producers of machinery, manufactures products composed of various features, within which a customer may select one of a number of possible options. On any given Deere product line, there may be tens of thousands of combinations of options (configurations) that are feasible. Maintaining such a large number of configurations inflates overhead costs; consequently, Deere wishes to reduce the number of configurations from their product lines without upsetting customers or sacrificing profits. In this paper, we provide a detailed explanation of the marketing and operational methodology used, and tools built, to evaluate the potential for streamlining two product lines at Deere. We illustrate our work with computational results from Deere, highlighting important customer behavior characteristics that impact product line diversity. For the two very different studied product lines, a potential increase in profit from 8% to 18% has been identified, possible through reducing the number of configurations by 20% to 50% from present levels, while maintaining the current high customer service levels. Based on our analysis and the insights it generated, Deere recently implemented a new product line strategy. We briefly detail this strategy, which has thus far increased profits by tens of millions of dollars.
Two-Stage Robust Network Flow and Design Under Demand Uncertainty
Authors: Atamtürk Alper , Zhang Muhong
Published: August 2007

We describe a two-stage robust optimization approach for solving network flow and design problems with uncertain demand. In two-stage network optimization, one defers a subset of the flow decisions until after the realization of the uncertain demand. Availability of such a recourse action allows one to come up with less conservative solutions compared to single-stage optimization. However, this advantage often comes at a price: two-stage optimization is, in general, significantly harder than single-stage optimization.

For network flow and design under demand uncertainty, we give a characterization of the first-stage robust decisions with an exponential number of constraints and prove that the corresponding separation problem is 𝒩𝒫-hard even for a network flow problem on a bipartite graph. We show, however, that if the second-stage network topology is totally ordered or an arborescence, then the separation problem is tractable.

Unlike single-stage robust optimization under demand uncertainty, two-stage robust optimization allows one to control conservatism of the solutions by means of an allowed “budget for demand uncertainty.” Using a budget of uncertainty, we provide an upper bound on the probability of infeasibility of a robust solution for a random demand vector.

We generalize the approach to multicommodity network flow and design, and give applications to lot-sizing and location-transportation problems. By projecting out second-stage flow variables, we define an upper bounding problem for the two-stage min-max-min optimization problem. Finally, we present computational results comparing the proposed two-stage robust optimization approach with single-stage robust optimization as well as scenario-based two-stage stochastic optimization.
Compensating for Failures with Flexible Servers
Authors: Andradóttir Sigrún , Ayhan Hayriye , Down Douglas G.
Published: August 2007

We consider the problem of maximizing capacity in a queueing network with flexible servers, where the classes and servers are subject to failure. We assume that the interarrival and service times are independent and identically distributed, that routing is probabilistic, and that the failure state of the system can be described by a Markov process that is independent of the other system dynamics. We find that the maximal capacity is tightly bounded by the solution of a linear programming problem and that the solution of this problem can be used to construct timed, generalized round-robin policies that approach the maximal capacity arbitrarily closely. We then give a series of structural results for our policies, including identifying when server flexibility can completely compensate for failures and when the implementation of our policies can be simplified. We conclude with a numerical example that illustrates some of the developed insights.
Index Policies for Shooting Problems
Authors: Glazebrook K. D. , Kirkbride C. , Mitchell H. M. , Gaver D. P. , Jacobs P. A.
Published: August 2007

We consider a scenario in which a single Red wishes to shoot at a collection of Blue targets, one at a time, to maximise some measure of return obtained from Blues killed before Red’s own (possible) demise. Such a situation arises in various military contexts, such as the conduct of air defence by Red in the face of Blue SEAD (suppression of enemy air defences). A class of decision processes called multiarmed bandits has been previously deployed to develop optimal policies for Red, in which she attaches a calibrating (Gittins) index to each Blue target and optimally shoots next at the Blue with the largest index value. The current paper seeks to elucidate how a range of developments of index theory are able to accommodate features of such problems, which are of practical military import. Such features include levels of risk to Red that are policy dependent, Red having imperfect information about the Blues she faces, an evolving population of Blue targets, and the possibility of Red disengagement. The paper concludes with a numerical study that both compares the performance of (optimal) index policies to a range of competitors and also demonstrates the value to Red of (optimal) disengagement.
An Exact Solution Approach for the Preferential Bidding System Problem in the Airline Industry
Authors: Achour Heykel , Gamache Michel , Soumis François , Desaulniers Guy
Published: August 2007

This paper introduces the first exact approach for constructing aircrew member personalized monthly work schedules when a preferential bidding system (PBS) is used. With such a system, each employee bids for his/her preferred activities, yielding a bidding score for each feasible schedule. The PBS problem thus consists of assigning to each employee a schedule that maximizes his/her preferences, in order of seniority, while covering all crew pairings. The proposed exact solution approach relies on column generation, and when a tentative maximum score for a crew member is established, it explicitly enumerates for that employee all feasible schedules with that score. Tests on real-life cases show that this approach can substantially improve the quality of the solutions produced by the best known existing method in similar computational times.
Incorporating Pricing Decisions into the Stochastic Dynamic Fleet Management Problem
Authors: Topaloglu Huseyin , Powell Warren
Published: August 2007

This paper shows how to coordinate the decisions on pricing and fleet management of a freight carrier. We consider a setting where the carrier announces its prices at the beginning of a certain time horizon and the load arrivals over this horizon depend on the announced prices. Assuming that the vehicle fleet is managed according to a particular class of fleet management models, we present a tractable method to obtain sample path-based directional derivatives of the objective function with respect to the prices. We use this information to search for a good set of prices. Numerical experiments show that our approach yields high-quality solutions.
Comparative optimism in the spontaneous generation of future life‐events
Authors: Hoorens Vera , Smits Tim , Shepperd James A.
Published: August 2007

We examined whether comparative optimism characterizes the events people generate when they describe their future. In contrast to previous studies in which participants estimated the likelihoods of experimenter‐generated events, our participants freely listed important events they believed were possible in their future versus the average person's future. They also provided desirability ratings, controllability ratings, and likelihood estimates for these self‐generated events. Participants listed more desirable and fewer undesirable events in their future than in the average person's future. These differences were stronger for controllable than uncontrollable events. Comparative optimism was also observed in participants' ratings of the likelihood of positive and negative events. Taken together, these findings suggest that a comparative optimism characterizes future expectations about spontaneously generated events as well as the pre‐selected events sampled in previous studies.
Evidence for different components in children's visuospatial working memory
Authors: Mammarella Irene C. , Pazzaglia Francesca , Cornoldi Cesare
Published: August 2007

There are a large number of studies demonstrating that visuospatial working memory (VSWM) involves different subcomponents, but there is no agreement on the identity of these dimensions. The present study attempts to combine different theoretical accounts by measuring VSWM. A battery composed of 13 tests was used to assess working memory and, in particular, the hypothesized mechanisms involved in the tasks, that is, active processing and passive recall of visual versus sequential‐spatial versus simultaneous‐spatial versus verbal tasks. The battery consisted of a number of tests already used in previous studies and new tests developed to examine specific components of working memory. We analysed the psychometric characteristics of the tests, the correlations amongst measured variables and estimated the measured variables with structural equation modelling in children attending third and fourth grades. Results revealed that the best model was composed of a specific verbal factor, three visuospatial passive factors (sequential‐spatial, simultaneous‐spatial, and visual) and one visuospatial active factor.
Fracture Incidence in GH-Deficient Patients on Complete Hormone Replacement Including GH
Authors: Holmer Helene , Svensson Johan , Rylander Lars , Johannsson Gudmundur , Rosén Thord , Bengtsson Bengt-Åke , Thorén Marja , Höybye Charlotte , Degerblad Marie , Bramnert Margareta , Hägg Erik , Engström Britt Edén , Ekman Bertil , Thorngren Karl-Göran , Hagmar Lars , Erfurth Eva-Marie
Published: August 2007

Fracture risk in GHD patients is not definitely established. Studying fracture incidence in 832 patients on GH therapy and 2581 matched population controls, we recorded a doubled fracture risk in CO GHD women, but a significantly lower fracture risk in AO GHD men.

Introduction: The objective of this study was to evaluate fracture incidence in patients with confirmed growth hormone deficiency (GHD) on replacement therapy (including growth hormone [GH]) compared with population controls, while also taking potential confounders and effect modifiers into account.

Materials and Methods: Eight hundred thirty-two patients with GHD and 2581 matched population controls answered a questionnaire about fractures and other background information. Incidence rate ratio (IRR) and 95% CI for first fracture were estimated. The median time on GH therapy for childhood onset (CO) GHD men and women was 15 and 12 yr, respectively, and 6 and 5 yr for adult onset (AO) GHD men and women, respectively.

Results: A more than doubled risk (IRR, 2.29; 95% CI, 1.23–4.28) for nonosteoporotic fractures was recorded in women with CO GHD, whereas no risk increase was observed among CO GHD men (IRR, 0.61) and AO GHD women (IRR, 1.08). A significantly decreased incidence of fractures (IRR, 0.54; 95% CI, 0.34–0.86) was recorded in AO GHD men.

Conclusions: Increased fracture risk in CO GHD women can most likely be explained by interaction between oral estrogen and the GH–IGF-I axis. The adequate substitution rate of testosterone (90%) and GH (94%) may have resulted in significantly lower fracture risk in AO GHD men.
Development of a True Triaxial Apparatus for Sands and Gravels
Authors: Choi Changho , Arduino Pedro , Harney Michael D.
Published: August 2007

This paper presents a recently developed true triaxial apparatus and a series of verification studies. The apparatus is capable of handling 241-mm cubical specimens providing the means for testing specimens under a wide variety of stress paths under drained and undrained conditions. It uses flexible boundaries to apply three independently controlled principal stresses with back pressure. The apparatus also uses a fully computer-controlled electro-pneumatic loading system with advanced technology for data control. A testing program is presented for the purpose of verification. Pea-gravel specimens with D50=6.6 mm were tested under fully stress-controlled loading conditions. Stress paths used in this verification study include undrained and drained constant total mean stress paths and conventional triaxial compression and extension stress paths. Results from this study indicate that the newly developed apparatus is capable of capturing the stress-strain characteristics of coarse-grained soils.
Management of Hereditary Angioedema in Pediatric Patients
Authors: Farkas Henriette , Varga Lilian , Széplaki Gábor , Visy Beáta , Harmat George , Bowen Tom
Published: August 2007

Hereditary angioneurotic edema is a rare disorder caused by the congenital deficiency of C1 inhibitor. Recurring angioedematous paroxysms that most commonly involve the subcutis (eg, extremities, face, trunk, and genitals) or the submucosa (eg, intestines and larynx) are the hallmarks of hereditary angioneurotic edema. Edema formation is related to reduction or dysfunction of C1 inhibitor, and conventional therapy with antihistamines and corticosteroids is ineffective. Manifestations occur during the initial 2 decades of life, but even today there is a long delay between the onset of initial symptoms and the diagnosis of hereditary angioneurotic edema. Although a variety of reviews have been published during the last 3 decades on the general management of hereditary angioneurotic edema, little has been published regarding management of pediatric hereditary angioneurotic edema. Thus, we review our experience and published data to provide an approach to hereditary angioneurotic edema in childhood.
Pathogenicity and drug resistance in Candida albicans and other yeast species
Authors: Mishra Nagendra , Prasad Tulika , Sharma Neeraj , Payasi Anurag , Prasad Rajendra , Gupta Dwijendra , Singh Randhir
Published: August 2007

Pathogenic yeasts from the genus
Candida
can cause serious infection in humans particularly, in immunocompromised patients and are now recognized as major agents of hospital acquired (nosocomial) infections. In the recent years, there has been a marked increase in the incidence of treatment failures in candidiasis patients receiving long-term antifungal therapy, which has posed a serious problem in its successful use in chemotherapy.
Candida
cells acquire drug resistance (MDR) during the course of the treatment. The mechanisms of resistance to azole antifungal agents have been elucidated in
Candida
species and can be mainly categorized as (i) changes in the cell wall or plasma membrane, which lead to impaired drug (azole) uptake; (ii) alterations in the affinity of the drug target Erg11p (lanosterol 14∝-demethylase) especially to azoles or in the cellular content of Erg11p due to target site mutation or overexpression of the
ERG11
gene; and (iii) the efflux of drugs mediated by membrane transport proteins belonging to the ATP-binding cassette (ABC) transporters, namely
CDR1
and
CDR2
or to the major facilitator superfamily (MFS) transporter,
CaMDR1
. Many such manifestations are associated with the formation of
Candida
biofilms including those occurring on devices like indwelling intravascular catheters. Biofilm-associated
Candida
show uniform resistance to a wide spectrum of antifungal drugs. A combination of different resistance mechanisms is responsible for drug resistance in clinical isolates of
Candida
species.
Involvement of chromosomally-encoded genes in malathion utilization by Pseudomonas aeruginosa AA112
Authors: Abo-Amer Aly
Published: August 2007

Malathion is an organophosphate insecticide that has been widely used for both domestic and commercial agricultural purposes. However, malathion has the potential to produce toxic effects in mammalian systems. In this study,
Pseudomonas aeruginosa
AA112 which was isolated from soil using enrichment technique could utilize the malathion as a sole carbon source and a source of energy.
Pseudomonas aeruginosa
AA112 was able to grow in MSMPY medium containing 42.75 mg/ml malathion. However, the optimum concentration of malathion which supported the maximum bacterial growth was found to be 22. 8 mg/ml. Malathion was used as an initial source of energy and carbon when it was found without additional carbon sources (in MSM medium) while it was utilized as second source of energy and carbon in a nutrient-supplemented medium (in MSMPY medium). Moreover, lead acetate test indicated that malathion was first attacked at a sulphur site 1–2 hours after the start of incubation. TLC and IR analysis indicated that malathion was completely degraded into diethyl succinate, hydrogen sulphide and phosphates. Therefore a malathion degradation pathway was proporsed. The degradation of malathion is attributed to the genes located on the chromosome and at least three proteins of high molecular size might be involved in malathion utilization. Bacteria able to use malathion as a food source or metabolize its residues in the environment to inactive, less toxic, and harmless compounds, could be used in bioremediation of an environmental pollution caused by the pesticide.
Prevalence and genotypes of hepatitis G virus/GB virus C in a multirisk group in Hungary
Authors: Dencs Ágnes , Sebestyén Ágnes
Published: August 2007

HGV/GBV-C is a mainly parenterally transmitted Flavivirus that causes a persistent infection. So far no disease has been associated with HGV/GBV-C infection, but its beneficial role in co-infection with the human immunodeficiency virus has been shown in many recent studies. The aim of our study was to determine the frequency of ongoing HGV/GBV-C infections among a sociologically unique group of the Hungarian population, who are at great risk for parenterally transmitted diseases. Viral RNA was detected in 75 serum samples by an RT-PCR method specific for the NS5 region. Nine (12%) samples were positive for HGV/GBV-C RNA. All nine PCR products were sequenced and a phylogenetic analysis was performed to identify the genotypes and subtypes of the detected viruses. All nine isolates proved to be genotype 2, eight of them were classified as subtype 2a, and one as subtype 2b.
Comamonas testosteroni bacteremia in a patient with perforated acute appendicitis
Authors: Gul Mustafa , Ciragil Pinar , Bulbuloglu Ertan , Aral Murat , Alkis Sumeyra , Ezberci Fikret
Published: August 2007

Comamonas testosteroni
is an uncommon isolate in the clinical laboratory as a human pathogen.
C. testosteroni
most commonly emerges in abdominal pathologies especially in perforated appendicitis. In Turkey we report first time a case of bacteremia due to this organism, in a 22-year-old man with perforated acute appendicitis. The organism was shown to be susceptible to routine antibiotics so it was easily eliminated even after having caused a bacteremia.
Experiences on non-metastatic rectum tumours irradiated only preoperatively
Authors: Patyánik Mihály , Solymosi Norbert , Bégányi Nóra , Sinkó Dániel , Mayer Árpád
Published: August 2007

Elfogadott ténynek számít, hogy a nem metastaticus rectumtumorok egyedüli preoperatív sugárterápiájával a lokálrecidíva-ráta 50%-kal csökkenthető.
Beteganyag és módszer:
1990 és 2001 között 181 rectumtumoros betegnél végeztünk preoperatív célú 36 Gy, illetve 40 Gy dózisú irradiációt. A stádiumba sorolást a módosított Astler–Coller patológiai staging szisztéma szerint végeztük. A sugárkezelést telekobalt-készülékkel, illetve nagyenergiájú fotonbesugárzóval végeztük számítógépes besugárzástervezést követően.
Eredmény:
A preoperatív sugárkezelés eredményességének legfontosabb fokmérője a lokálrecidíva-ráta, mely anyagunkban 21,56%-os volt. Szignifikánsan befolyásolta a túlélést a beteg kora és az alkalmazott dózis nagysága.
Következtetés:
Rectumtumoros beteganyagunk statisztikai analízise az egyedüli preoperatív sugárkezelés hatékonyságát vizsgálta. Az eredmények megfeleltek az erre vonatkozó közleményekben közöltekkel.
Our experiences in Trans-Obturator Tape surgery after performing 150 cases
Authors: Csorba Roland , Lampé Rudolf , Simó Dezső , Bacskó György , Póka Róbert
Published: August 2007

Európában a felnőtt nők közel 30 százaléka szenved a vizelet-visszatartás zavarától. A néhány éve megjelent Trans-Obturator Tape (TOT) műtét egy újabb lehetőséget ad a stresszinkontinencia műtéti gyógyítására.
Betegek és módszerek:
A kivizsgálás részletes anamnézisfelvételből, stressz- és Q-tip-tesztet is magában foglaló, általános és nőgyógyászati fizikális vizsgálatból, illetve a QUID- (The Questionnaire for Urinary lncontinence Diagnosis) kérdőív kitöltéséből állt. Nem egyértelmű esetekben urodinámiás vizsgálat történt. A szerzők százötven betegen végeztek Trans-Obturator Tape beültetést. A
műtét eredményességének értékelését szintén QUID-kérdőívek segítségével végezték.
Eredmények:
A betegek átlagéletkora 50,8 év volt (SD = 8,64). 69 páciensnek (46%) volt tisztán stresszinkontinenciája, 33 betegnek (22%) késztetéses inkontinenciája, míg 48 esetben (32%) stresszdominanciával kevert inkontinenciát mutattak ki. Az átlagos követési idő 16 hónap (4–26 hónap) volt. A stresszinkontinencia átlagos preoperatív súlyossági pontértéke 11,78, az urge-komponensé 6,63 volt. Az átlagos műtéti idő 25 perc volt. 150 műtét kapcsán szövődményt 4 esetben észleltek. 12 betegnek volt szüksége katéter viselésére 24 órán túl, a leghosszabb katéterezési idő 5 nap volt. Az átlagos ápolási idő 4,76 nap (SD = 0,8) volt. A posztoperatív kérdőívek elemzésekor a stresszkomponensre vonatkozó átlagos súlyossági pont 2,22, az urge-komponensé 2,59 volt. Az elégedettségi felmérésben 46 beteg nagyon jónak (47,4%), 39 jónak (40,2%), 7 közepesnek (7,2%), 3 gyengének (3,1%), 2 beteg pedig eredménytelennek (2,1%) ítélte meg a beavatkozást.
Következtetések:
A módszer avatott kezekben kiemelkedő hatékonyságú, minimálinvazív, gyors műtét, mely rövid kórházi ápolással és kevés szövődménnyel jár.
Fantasies of the New Class: The New Criticism, Harvard Sociology, and the Idea of the University
Authors: Schryer Stephen
Published: August 2007

This essay examines the professionalization of United States literary studies and sociology between the 1930s and 1950s under the aegis of John Crowe Ransom's New Criticism and Talcott Parsons's structural functionalism. These paradigms pulled the disciplines to opposite poles of the professional class: Ransom argued for a less sociological literary criticism, while Parsons distanced sociology from the literary tendencies of the Chicago school. However, both implemented similar professional ideologies that synthesized their disciplines' technical and moral claims, and both paradigms involved fantasies that specialized, disciplinary work within the academy can have a broader, moral significance. These ideas remained fantasies, which contradicted the actual effects of the New Criticism and structural functionalism; professionalism became reflexively oriented toward disciplinary self-perpetuation, isolating literature and sociology from the public they were supposed to reform. Ransom and Parsons thus exemplify the disintegration of publicly responsible professionalism—an event with broad implications for the “new class” of postwar knowledge workers.
Devouring Posterity:A Modest Proposal, Empire, and Ireland's “Debt of the Nation”
Authors: Moore Sean
Published: August 2007

Scholars have rightly asserted that the cannibal motif of Jonathan Swift'sA Modest Proposalis the mechanism by which the author covertly addresses colonialist pillaging in Ireland. Less attention has been paid to an unresolved problem, that of the satire's audience. This article claims that its publication in Dublin at the height of the Irish parliamentary session of 1729 suggests that Anglo-Irish legislators were its target readers. If so, the figure of the cannibal may signify how national debt and the mortgaging of future public revenues needed to amortize that debt metaphorically devoured the posterity of the colonized Irish natives. Given that the famine conditions of 1729 had reduced revenues and produced a crisis in paying Ireland's “debt of the nation,” the satire's calendar for the harvesting and slaughtering of Ireland's babies could be taken as mimicry of the debates over how to raise new taxes and schedule their collection and expenditure.
Godwin's Handshake
Authors: Franta Andrew
Published: August 2007

This essay argues that William Godwin's novelCaleb Williamsuses a familiar gesture—the handshake—to contest both radical and conservative responses to the French Revolution. Instead of merely fictionalizing the arguments of hisEnquiry concerning Political Justice, as critics have argued,Caleb Williams, through Godwin's representation of the repeated failure of this socially and politically significant gesture, traces an episode in the history of manners. The handshake thus points to a historical development, the emergence of commercial society, that complicates the novel's political stance by undermining the conception of politics that underwrites it.
Optimum Allocation for Soil Contamination Investigations in Hsinchu, Taiwan, by Double Sampling
Authors: Chang Ya-Chi , Yeh Hund-Der
Published: August 2007

The double sampling (DS) scheme is a cost‐effective sampling method that combines an expensive measurement procedure with an inexpensive but less accurate one. Double sampling works when the true correlation of determination (ρ2) between two techniques is known in advance, but that is hardly ever the case. By assuming a ρ2 < 0.9, a three‐stage procedure (TSP) in DS selects a preliminary pool of samples and estimates ρ2, from which the optimal allocation of samples is determined. There may be excessive and unnecessary sampling during a TSP when ρ2 > 0.9. The main objective of this study was to extend the TSP and determine the optimum allocation of the samples under a fixed budget condition for the case ρ2 > 0.9. A soil from Hsinchu, Taiwan, contaminated with heavy metals Zn, Cu, Pb, Ni, Cr, and Cd was sampled at 0.15, 0.3, 0.45, and 0.6 m deep at 36 sites (144 samples). All samples were analyzed with field‐portable x‐ray fluorescence and a subset of 40 samples was selected for analyses of Zn, Cu, and Pb with standard methods in the laboratory. Results from both measurements were linearly correlated with estimated ρ2 values of 0.96, 0.95, and 0.97 for Zn, Cu, and Pb, respectively. Considering a ρ2 = 0.99, the optimum subsample and sample sizes were 5 out of 167, 4 out of 173, and 5 out of 167 for Zn, Cu, and Pb, respectively. The extended TSP analyses reduced the number of superfluous samples to only two or three, which was less than obtained by TSP (9–16).
Experimental Investigation of Direct Connectivity between Macropores and Subsurface Drains during Infiltration
Authors: Akay Onur , Fox Garey A.
Published: August 2007

Recent research indicates immediate breakthrough of surface‐applied contaminants in subsurface drainage by transport through macropores directly connected to the surface. This “direct connectivity” phenomenon was verified and investigated by conducting infiltration experiments (1‐cm ponded water at the soil surface) in a laboratory soil column (sandy loam soil with bulk density of 1.6 g cm−3) with a vertical artificial macropore placed directly above or shifted away from a lateral subsurface drain. The experimental setup allowed surface‐connected and buried macropore lengths to be varied from the surface to the subsurface drain depth without unpacking or disturbing the soil column between experiments. It was observed that the longer the buried macropore length (i.e., as the macropore approached the soil surface), the more rapid the response at the drain outlet in addition to an increased percentage of total drain flow through the macropore (35–40%). Breakthrough with surface‐connected macropores was significantly faster than with buried macropores, suggesting that breaking surface connectivity of macropores by tillage may be an important management strategy. For surface‐connected macropore experiments, the average ratio of steady‐state total (macropore and matrix) to matrix flow rates decreased as the distance from the drain increased: 2.4, 2.1, and 1.6 for distances of 0, 6.25, and 12.5 cm, respectively. Extrapolating this data to distances beyond 12.5 cm suggested that macropores located within 20 to 25 cm of the drain act as though directly connected in this sandy loam soil. This research verifies the “contributing area” concept hypothesized in previous field and numerical modeling studies.
Proteolytic Degradation of VE-Cadherin Alters the Blood-Retinal Barrier in Diabetes
Authors: Navaratna Deepti , McGuire Paul G. , Menicucci Gina , Das Arup
Published: August 2007

OBJECTIVE— Increased vascular permeability due to alteration of the blood-retinal barrier (BRB) is one of the major complications in early diabetes. The aim of the present study was to determine whether diabetes alters the cellular expression and distribution of the adherens junction protein vascular endothelial (VE)-cadherin in retinal endothelial cells and if this alteration is mediated by proteinase activity.

RESEARCH DESIGN AND METHODS— Diabetes was induced in Brown Norway rats using streptozotocin, and retinal vascular permeability was measured by the Evans blue technique. The expression of matrix metalloproteinases (MMPs) and VE-cadherin was examined in isolated retinal vessels or cultured endothelial cells in response to diabetes and advanced glycation end products (AGEs). The cleavage of VE-cadherin from the endothelial cell surface was monitored by Western blotting following MMP or AGE treatment.

RESULTS— Retinal vascular permeability was significantly increased in rats following 2 weeks of diabetes coincident with a decrease of VE-cadherin expression. This increased vascular permeability could be inhibited with an MMP inhibitor. Treatment of endothelial cells with AGE-BSA led to a reduction of VE-cadherin staining on the cell surface and increased permeability, which was MMP mediated. Treatment of cells with specific MMPs or AGEs resulted in cleavage of VE-cadherin from the cell surface.

CONCLUSIONS— These observations suggest a possible mechanism by which diabetes contributes to BRB breakdown through proteolytic degradation of VE-cadherin. This may indicate a role for extracellular proteinases in alteration of the BRB seen in diabetic retinopathy.