bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Partition Length on Natural Convection in Partially Divided Square Enclosure
Authors: Sankhavara C. D. , Shukla H. J.
Published: November 2007

Numerical investigation is carried out for natural convection in square enclosures consisting of partitions protruding from the end walls with different thermal boundary conditions at the end walls and partitions. The vertical walls were maintained isothermal at different temperatures. The Rayleigh number varies from 104 to 106 and the Prandtl number is 0.71. The thickness of the partition is fixed and is equal to one-tenth of the width of the enclosure. Their nondimensional length (l∕H) varies from 0 (a nonpartitioned enclosure) to 0.5 (two separate enclosures). A good agreement was found between the results in the present study and those published previously. The partitions were found to significantly influence the convective heat transfer. The average Nusselt number is less in the presence of partitions, and it decreases with increasing partition length (l∕H) from 0 to 0.5.
Thermomechanical Formation of Nanoscale Polymer Indents With a Heated Silicon Tip
Authors: King William P. , Goodson Kenneth E.
Published: November 2007

In thermomechanical data storage, a heated atomic force microscope cantilever tip is in contact with and scans over a polymer film. Heating in the cantilever and cantilever tip induces local deformation of the polymer near the tip, with indents as small as 22nm. This paper reports a simple modeling approach for predicting heat and mass transfer in the cantilever tip and polymer with the goal of predicting indent formation conditions. The model accounts for subcontinuum conduction in the cantilever tip and for the time- and temperature-dependent mechanical properties of the polymer. Simulations predict steady state and transient indent formation, and the results compare well with data. For loading forces 30–200nN and a tip radius of 20nm, a cantilever temperature of 200°C is required to form an indent at steady state. For heating pulses as short as 5μs, the cantilever temperature required for bit formation is as high as 500°C. By quantifying the conditions required for indent formation, this work may improve the operation of heated probes for thermomechanical data storage.
Roles of α and β Carbonic Anhydrases of
Helicobacter pylori
in the Urease-Dependent Response to Acidity and in Colonization of the Murine Gastric Mucosa
Authors: Bury-Moné Stéphanie , Mendz George L. , Ball Graham E. , Thibonnier Marie , Stingl Kerstin , Ecobichon Chantal , Avé Patrick , Huerre Michel , Labigne Agnès , Thiberge Jean-Michel , De Reuse Hilde
Published: November 2007

Carbon dioxide occupies a central position in the physiology of
Helicobacter pylori
owing to its capnophilic nature, the large amounts of carbon dioxide produced by urease-mediated urea hydrolysis, and the constant bicarbonate supply in the stomach. Carbonic anhydrases (CA) catalyze the interconversion of carbon dioxide and bicarbonate and are involved in functions such as CO
2
transport or trapping and pH homeostasis.
H. pylori
encodes a periplasmic α-CA (α-CA-HP) and a cytoplasmic β-CA (β-CA-HP). Single CA inactivation and double CA inactivation were obtained for five genetic backgrounds, indicating that
H. pylori
CA are not essential for growth in vitro. Bicarbonate-carbon dioxide exchange rates were measured by nuclear magnetic resonance spectroscopy using lysates of parental strains and CA mutants. Only the mutants defective in the α-CA-HP enzyme showed strongly reduced exchange rates. In
H. pylori
, urease activity is essential for acid resistance in the gastric environment. Urease activity measured using crude cell extracts was not modified by the absence of CA. With intact CA mutant cells incubated in acidic conditions (pH 2.2) in the presence of urea there was a delay in the increase in the pH of the incubation medium, a phenotype most pronounced in the absence of
H. pylori
α-CA. This correlated with a delay in acid activation of the urease as measured by slower ammonia production in whole cells. The role of CA in vivo was examined using the mouse model of infection with two mouse-adapted
H. pylori
strains, SS1 and X47-2AL. Compared to colonization by the wild-type strain, colonization by X47-2AL single and double CA mutants was strongly reduced. Colonization by SS1 CA mutants was not significantly different from colonization by wild-type strain SS1. However, when mice were infected by SS1 Δ(β-CA-HP) or by a SS1 double CA mutant, the inflammation scores of the mouse gastric mucosa were strongly reduced. In conclusion, CA contribute to the urease-dependent response to acidity of
H. pylori
and are required for high-grade inflammation and efficient colonization by some strains.
Pseudomonas aeruginosa
RsmA Plays an Important Role during Murine Infection by Influencing Colonization, Virulence, Persistence, and Pulmonary Inflammation
Authors: Mulcahy Heidi , O'Callaghan Julie , O'Grady Eoin P. , Maciá María D. , Borrell Nuria , Gómez Cristina , Casey Pat G. , Hill Colin , Adams Claire , Gahan Cormac G. M. , Oliver Antonio , O'Gara Fergal
Published: November 2007

The ability of
Pseudomonas aeruginosa
to cause a broad range of infections in humans is due, at least in part, to its adaptability and its capacity to regulate the expression of key virulence genes in response to specific environmental conditions. Multiple two-component response regulators have been shown to facilitate rapid responses to these environmental conditions, including the coordinated expression of specific virulence determinants. RsmA is a posttranscriptional regulatory protein which controls the expression of a number of virulence-related genes with relevance for acute and chronic infections. Many membrane-bound sensors, including RetS, LadS, and GacS, are responsible for the reciprocal regulation of genes associated with acute infection and chronic persistence. In
P. aeruginosa
this is due to sensors influencing the expression of the regulatory RNA RsmZ, with subsequent effects on the level of free RsmA. While interactions between an
rsmA
mutant and human airway epithelial cells have been examined in vitro, the role of RsmA during infection in vivo has not been determined yet. Here the function of RsmA in both acute and chronic models of infection was examined. The results demonstrate that RsmA is involved in initial colonization and dissemination in a mouse model of acute pneumonia. Furthermore, while loss of RsmA results in reduced colonization during the initial stages of acute infection, the data show that mutation of
rsmA
ultimately favors chronic persistence and results in increased inflammation in the lungs of infected mice.
Paleocene submarine-canyon fill, Point Lobos, California
Authors: Clifton H. Edward , Hill Gary W.
Published: November 2007

Point Lobos, a prominent headland at the southern side of Carmel Bay on the central California coast (Fig.1), is the site of a popular state reserve. Entrance to this reserve is from California 1, about 4 mi(6.4 km) south of the village of Carmel and 2.5 mi(4 km) southwest of the intersection of California 1 and Carmel Valley Road (County Road G16). Within the reserve, paved roads and well-maintained foot trails provide excellent access to many of the more prominent exposures (Fig.1). Outcrops not served by foot trails are off-limits to the public; however, the geologically important exposuresdescribed herein are readily accessible. Point LobosState Reserve is beautifully maintained in a pristine condition by its staff, and the rules are strictly enforced. Most important, froma geologic standpoint, are strictures against collecting or disturbing any natural object within the reserve, so geological hammers are best left in vehicles. The rocks of the reserve are a striking esthetic resource and a mecca for amateur and professional photographers—they are not to be defaced. The reserve opens in the morning (typically at 9:00) and closes before sundown. A nominal entrance fee is charged to visitors.
Geodynamic Significance of Seismic Anisotropy of the Upper Mantle: New Insights from Laboratory Studies
Authors: Karato Shun-ichiro , Jung Haemyeong , Katayama Ikuo , Skemer Philip
Published: November 2007

Seismic anisotropy is caused mainly by the lattice-preferred orientation of anisotropic minerals. Major breakthroughs have occurred in the study of lattice-preferred orientation in olivine during the past ∼10 years through large-strain, shear deformation experiments at high pressures. The role of water as well as stress, temperature, pressure, and partial melting has been addressed. The influence of water is large, and new results require major modifications to the geodynamic interpretation of seismic anisotropy in tectonically active regions such as subduction zones, asthenosphere, and plumes. The main effect of partial melting on deformation fabrics is through the redistribution of water, not through a change in deformation geometry. A combination of new experimental results with seismological observations provides new insights into the distribution of water associated with plume-asthenosphere interactions, formation of the oceanic lithosphere, and subduction. However, large uncertainties remain regarding the role of pressure and the deformation fabrics at low stress conditions.
Abrupt Climate Changes: How Freshening of the Northern Atlantic Affects the Thermohaline and Wind-Driven Oceanic Circulations
Authors: Barreiro Marcelo , Fedorov Alexey , Pacanowski Ronald , Philander S. George
Published: November 2007

Leading hypotheses for abrupt climate changes are focused on the ocean response to a freshening of surface waters in the north Atlantic. The degree to which such a freshening affects the deep, slow thermohaline, rather than the shallow, swift, wind-driven circulations of the ocean, and hence the degree to which that freshening affects climate in high rather than low latitudes, differ from model to model, depending on factors such as the treatment of diffusive processes in the oceans. Many comprehensive climate models are biased and confine the influence mainly to the thermohaline circulation and northern climates. Simulations of paleoclimates can provide valuable tests for the models, but only some of those climates provide sufficiently stringent tests to determine which models are realistic.
Heparanase modulates heparinoids anticoagulant activities via non-enzymatic mechanisms
Authors: Muhl Lars , Zwang Etty , Ilan Neta , Herishanu Yair , Deutsch Varda , Naparstek Elizabeth , Vlodavsky Israel , Preissner Klaus , Katz Ben-Zion
Published: November 2007

A key element for the physiological restriction of blood coagulation at the endothelial cell surface is its non-thrombogenic property, mainly attributed to cell surface heparan sulfate proteoglycans. Heparanase is an endo-β-D-glucuronidase with specific heparan sulfate degrading activity, which is produced and stored in platelets, and is released upon their activation. We examined the effects of heparanase pro-enzyme on coagulation functions, predominantly under physiological conditions. While heparanase pro-enzyme does not directly affect coagulation protein activities, it has profound effects on heparinoid-mediated regulation of coagulation responses, apparently via mechanisms that do not involve its enzymatic activity. Heparanase pro-enzyme reverses the anti-coagulant activity of unfractionated heparin on the coagulation pathway as well as on thrombin activity. In addition, heparanase pro-enzyme abrogated the factor X inhibitory activity of low-molecular-weight heparin (LMWH). The pro-coagulant effects of the non-active heparanase were also exerted by its major functional heparin-binding peptide. Finally, the effects of heparanase on the activity of factor VII activating protease that is auto-activated by heparinoids indicated a complete antagonistic action of heparanase in this system. Altogether, heparanase pro-coagulant activities that were also demonstrated in plasma samples from patients under LMWH treatment,point to a possible use of this molecule as antagonist for heparinoid treatment.
Effect of clopidogrel treatment on stress-induced platelet activation and myocardial ischemia in aspirin-treated patients with stable coronary artery disease
Authors: Perneby Christina , Wallén Håkan , Hofman-Bang Claes , Tornvall Per , Ivert Torbjörn , Li Nailin , Hjemdahl Paul
Published: November 2007

Stress may counteract responses to antiplatelet drug treatment. We investigated if adding clopidogrel to aspirin treatment could attenutate stress-induced platelet activation and myocardial ischemia in patients with coronary artery disease (CAD). Thirty-one male patients with documented CAD-treated with aspirin (75–160 mg daily) were randomized to co-treatment with clopidogrel (n=16) or placebo (n=15). A symptom-limited exercise test and 48-hour (h) Holter monitoring were performed before and after two weeks of double-blind treatment. Platelet function was assessed by flow cytometry and impedance aggregometry in whole blood. Exercise-induced and ambulatory ischemia was assessed from electrocardiographic (ECG) recordings. Clopidogrel treatment inhibited ADP-induced platelet P-selectin expression by 64% (22–87%), and attenuated the P-selectin response to thrombin (p<0.001), and platelet aggregation induced by low-dose collagen (p<0.01). Exercise (≈110W) increased heart rate similarly, and caused ≈1.8 mm STsegment depression both before and after treatment. Exercise caused platelet activation, i.e. increased circulating activated single platelets and platelet-platelet aggregates, enhanced the invitro responsiveness to ADP or thrombin stimulation, and increased platelet-leukocyte aggregation. Clopidogrel inhibited ADP-induced platelet activation to a similar relative degree at rest and during exercise, but did not attenuate the platelet activating effect of exercise. Addition of clopidogrel to aspirin treatment did not attenuate either ambulatory or exercise-induced ischemia. In conclusion, adding clopidogrel to aspirin treatment inhibited platelet activation by both ADP, thrombin and collagen in vitro,but did not influence the prothrombotic responses to exercise. Intensified antiplatelet treatment did not reduce ECG signs of either exercise-induced or ambulatory myocardial ischemia.
Risk stratification and heparin prophylaxis to prevent venous thromboembolism in pregnant women
Authors: Dudenhausen Joachim , Faridi Andree , Fischer Thorsten , Fung Samson , Geisen Ulrich , Harenberg Job , Herchenhan Eberhard , Keller Franz , Kemkes-Matthes Bettina , Schinzel Helmut , Spannagl Michael , Thaler Christian , Bauersachs Rupert ,   the EThIG Investigators
Published: November 2007

Women with a history of venous thromboembolism (VTE), thrombophilia or both may be at increased risk of thrombosis during pregnancy, but the optimal management strategy is not well defined in clinical guidelines because of limited trial data. A strategy of risk assessment and heparin prophylaxis was evaluated in pregnant women at increased risk of VTE. In a prospective trial (Efficacy of Thromboprophylaxis as an Intervention during Gravidity [EThIG]), 810 pregnant women were assigned to one of three management strategies according to pre-defined risk factors related to history of VTE and thrombophilic profile. Low-risk women (group I), received 50–100 IU dalteparin/ kg body weight/ day for 14 days postpartum, or earlier when additional risk factors occurred. Women at high (group II) or very high risk (group III) received dalteparin from enrolment until six weeks postpartum (50–100 IU and 100–200 IU/ kg/ day, respectively). Objectively confirmed, symptomatic VTE occurred in 5/810 women (0.6%; 95% confidence interval [CI], 0.2 to 1.5%) (group I, 0 of 225; II, 3/469; III, 2/116). The rate of serious bleeding was 3.0% (95 % CI, 1.9 to 4.4%); 1.1% (95 % CI, 0.5 to 2.2%) was possibly dalteparin-related. There was no evidence of heparin- induced thrombocytopenia, one case of osteoporosis, and rates of miscarriage and stillbirth were similar to previous, retrospective studies. Risk-stratified heparin prophylaxis was associated with a low incidence of symptomatic VTE and few clinically important adverse events. Antepartum heparin prophylaxis is, therefore, warranted in pregnant women with idiopathic thrombosis or symptomatic thrombophilia.
Association of Dietary Intake of Soy, Beans, and Isoflavones With Risk of Cerebral and Myocardial Infarctions in Japanese Populations
Authors: Kokubo Yoshihiro , Iso Hiroyasu , Ishihara Junko , Okada Katsutoshi , Inoue Manami , Tsugane Shoichiro
Published: November 2007

Background—

Soy and isoflavones have been proposed to reduce the risk of cardiovascular risk factors, but their potential as preventatives for cardiovascular disease remains uncertain. We investigated the association of soy and isoflavone intake with risk of cerebral and myocardial infarctions (CI and MI).

Methods and Results—

To examine the association of soy and isoflavone intake with the risk of CI and MI, we studied 40 462 Japanese (40 to 59 years old, without cardiovascular disease or cancer at baseline). They completed a food-frequency questionnaire (1990–1992) and received follow-up to 2002. After 503 998 person-years of follow-up, we documented incidence of CI (n=587) and MI (n=308) and of mortality for CI and MI combined (n=232). For women, the multivariable hazard ratios and 95% confidence limits for soy intake ≥5 times per week versus 0 to 2 times per week were 0.64 (0.43 to 0.95) for risk of CI, 0.55 (0.26 to 1.09) for risk of MI, and 0.31 (0.13 to 0.74) for cardiovascular disease mortality. Similar but weaker inverse associations were observed between intake of miso soup and beans and risk of cardiovascular disease mortality. The multivariable hazard ratios for the highest versus the lowest quintiles of isoflavones in women were 0.35 (0.21 to 0.59) for CI, 0.37 (0.14 to 0.98) for MI, and 0.87 (0.29 to 2.52) for cardiovascular disease mortality. An inverse association between isoflavone intake and risk of CI and MI was observed primarily among postmenopausal women. No significant association of dietary intake of soy, miso soup, and beans and isoflavones with CI or MI was present in men.

Conclusions—

High isoflavone intake was associated with reduced risk of CI and MI in Japanese women. The risk reduction was pronounced for postmenopausal women.
Effect of Antecedent Hypertension and Follow-Up Blood Pressure on Outcomes After High-Risk Myocardial Infarction
Authors: Thune Jens J. , Signorovitch James , Kober Lars , Velazquez Eric J. , McMurray John J.V. , Califf Robert M. , Maggioni Aldo P. , Rouleau Jean L. , Howlett Jonathan , Zelenkofske Steven , Pfeffer Marc A. , Solomon Scott D.
Published: November 2007

The influence of blood pressure on outcomes after high-risk myocardial infarction is not well characterized. We studied the relationship between blood pressure and the risk of cardiovascular events in 14 703 patients with heart failure, left ventricular systolic dysfunction, or both after acute myocardial infarction in the Valsartan in Myocardial Infarction Trial. We assessed the relationship between antecedent hypertension and outcomes and the association between elevated (systolic: >140 mm Hg) or low blood pressure (systolic: <100 mm Hg) in 2 of 3 follow-up visits during the first 6 months and subsequent cardiovascular events over a median 24.7 months of follow-up. Antecedent hypertension independently increased the risk of heart failure (hazard ratio [HR]: 1.19; 95% CI: 1.08 to 1.32), stroke (HR: 1.27; 95% CI: 1.02 to 1.58), cardiovascular death (HR: 1.11; 95% CI: 1.01 to 1.22), and the composite of death, myocardial infarction, heart failure, stroke, or cardiac arrest (HR: 1.13; 95% CI: 1.06 to 1.21). While low blood pressure in the postmyocardial infarction period was associated with increased risk of adverse events, patients with elevated blood pressure (n=1226) were at significantly higher risk of stroke (adjusted HR: 1.64; 95% CI: 1.17 to 2.29) and combined cardiovascular events (adjusted HR: 1.14; 95% CI: 1.00 to 1.31). Six months after a high-risk myocardial infarction, elevated systolic blood pressure, a potentially modifiable risk factor, is associated with an increased risk of subsequent stroke and cardiovascular events. Whether aggressive antihypertensive treatment can reduce this risk remains unknown.
Fuzzy Set Theory for Performance Evaluation in a Surgical Simulator
Authors: Hajshirmohammadi Ima , Payandeh Shahram
Published: November 2007

Increasing interest in computer-based surgical simulators as time- and cost-efficient training tools has introduced a new problem: objective evaluation of surgical performance based on scoring metrics provided by surgical simulators. This project employed fuzzy set theory to design a classifier for performance of a subject training on a surgical simulator, using three categories: novice, intermediate, and expert.

The MIST-VR simulator was used in a user study of 26 subjects with three different surgical skill levels: 8 experienced laparoscopic surgeons (experts), 8 surgical assistants (intermediates), and 10 nurses (novices). Subjects were required to perform four trials of a suturing task and a knot-tying task on the simulator. The performance data were then used to train and test two fuzzy classifiers for each task. The fuzzy classifier was able to classify the users of the system. The models presented a highly nonlinear relationship between the inputs (performance metrics) and output (fuzzy score) of the system, which may not be effectively captured with classical classification approaches. Fuzzy classifiers, however, can offer effective tools to handle the complexity and fuzziness of objective evaluation of surgical performances.
Force Feedback Control of a Medical Haptic Master using an Electrorheological Fluid
Authors: Han Young-Min , Kang Pil-Soon , Sung Kum-Gil , Choi Seung-Bok
Published: November 2007

This study presents force feedback control performance of a spherical haptic device featuring an electrorheological (ER) fluid that can be used for minimally invasive surgery (MIS). As a first step, a spherical ER joint composed of rotational and stationary electrodes is designed and optimized based on mathematical torque modeling. The active force produced in MIS is generally small, even though the passive force is large. In order to meet this agreement, both clutch and brake mechanism are adopted for the ER joint. In this operation, the active (small) force feedback by the rotational electrodes and/or semi-active (large) force feedback are achieved by the stationary electrode. Subsequently, the master device is manufactured by integration of the spherical ER joint with AC motor. In order to achieve desired force trajectories, a sliding mode controller, which is robust to uncertainty, is formulated by considering mechanical friction and hysteretic behavior of the ER fluid as uncertainty. The controller is then experimentally realized. Tracking control performances for various force trajectories are presented in time domain.
A Low Force Magneto-rheological (MR) Fluid Damper: Design, Fabrication and Characterization
Authors: Aydar Gokhan , Evrensel Cahit A. , Gordaninejad Faramarz , Fuchs Alan
Published: November 2007

This study focuses on the theoretical analysis, design, fabrication and characterization of a small Magneto-Rheological (MR) fluid damper. It can be potentially applied to a horizontal axis, front-loading washing machine. In such washing machines, although washing cycle is slow, spin cycle is much faster. During acceleration from washing cycle to spin cycle, the tub passes through its resonant speed requiring relatively high damping. On the other hand, high damping results in increased force transmission to the housing and noise at high-speed spin cycle. Controllability of the MR fluid damper allows adjustment of damping requirements for different cycles and helps to reduce the noise at high speed spin cycle while limiting the tub motion at resonance. A patented geometry of an MR valve developed by Composite and Intelligent Materials Laboratory at the University of Nevada, Reno is used as the basis of this new design to satisfy the requirements of the application. Fabricated prototype damper is characterized using harmonic displacement input. Test results are in good agreement with the theoretical predictions and design values.
A New MR Fluid-Elastomer Vibration Isolator
Authors: York David , Wang Xiaojie , Gordaninejad Faramarz
Published: November 2007

In this study, the performance of a new design concept utilizing a magnetorheological (MR) fluid composite material is examined through encapsulating a MR fluid into an elastomer. A prototype MR Fluid-Elastomer (MRF-E) Vibration Isolator is built and its dynamic behavior is studied in oscillatory compressions for a wide range of frequencies under various applied magnetic fields. The experimental results show that both the stiffness and the damping capability of the MRF-E Vibration Isolator is a function of the displacement amplitude and magnetic field strength, and only weakly dependent upon the frequency of excitation. This demonstrates that the new vibration isolator, whose mechanical properties can be controlled by an applied magnetic field, has potential in applications where tuning vibration characteristics are desired.
Review Series: Lung function made easy: Assessing gas exchange
Authors: Hughes J.M.B.
Published: November 2007

In clinical practice there are two sorts of measurements, a) arterial oxygen and carbon dioxide partial pressure (PaO2, PaCO2) or arterial oxygen saturation (SaO2), and b) the transfer capacity for carbon monoxide (TLCO). The former measures the output or performance of the lung as a gas exchanger, and the latter estimates the available surface area or potential for gas exchange. As gas exchange deteriorates (PaO2 falls and PaCO2 rises), the body compensates by increasing ventilation and lowering PaCO 2. Therefore, a high PaCO2 represents chronic respiratory or “compensation” failure, either chemo-insensitivity (“won't breathe”) or neuromuscular weakness/increased work of breathing (“cannot breathe”). Chronic respiratory failure may progress to acute failure in which PaCO2 falls and PaCO2 rises progressively, assisted ventilation is usually required. The TLCO is a laboratory test which measures the integrity of the blood-gas barrier, it is particularly useful in the assessment of emphysema, interstitial disease and pulmonary vascular disease. Chronic Respiratory Disease 2007; 4: 205—214
Gene transactivation without direct DNA binding defines a novel gain-of-function for PML-RARα
Authors: van Wageningen Sake , Breems-de Ridder Marleen C. , Nigten Jeannet , Nikoloski Gorica , Erpelinck-Verschueren Claudia A. J. , Löwenberg Bob , de Witte Theo , Tenen Daniel G. , van der Reijden Bert A. , Jansen Joop H.
Published: November 2007

PML-RARα is the causative oncogene in 5% to 10% of the cases of acute myeloid leukemia. At physiological concentrations of retinoic acid, PML-RARα silences RARα target genes, blocking differentiation of the cells. At high concentrations of ligand, it (re)activates the transcription of target genes, forcing terminal differentiation. The study of RARα target genes that mediate this differentiation has identified several genes that are important for proliferation and differentiation control in normal and malignant hematopoietic cells. In this paper, we show that the PML-RARα fusion protein not only interferes with the transcription of regular RARα target genes. We show that the ID1 and ID2 promoters are activated by PML-RARα but, unexpectedly, not by wild-type RARα/RXR. Our data support a model in which the PML-RARα fusion protein regulates a novel class of target genes by interaction with the Sp1 and NF-Y transcription factors, without directly binding to the DNA, defining a gain-of-function for the oncoprotein.
Screening for hemochromatosis by measuring ferritin levels: a more effective approach
Authors: Waalen Jill , Felitti Vincent J. , Gelbart Terri , Beutler Ernest
Published: November 2007

Because the penetrance of HFE hemochromatosis is low, traditional population screening measuring the transferrin saturation is unlikely to be cost-effective because the majority of subjects detected neither have clinical disease nor are likely to develop it. Three independent studies show that only patients with serum ferritin concentrations more than 1000 μg/L are at risk for cirrhosis, one of the main morbidities of hemochromatosis. Among 29 699 white subjects participating in the Scripps/Kaiser hemochromatosis study, only 59 had serum ferritin levels more than 1000 μg/L; 24 had homozygous mutant or compound heterozygous mutant HFE genotypes. In all but 5 of the other subjects, the causes of elevated ferritin were excessive alcohol intake, cancer, or liver disease. Screening for hemochromatosis with serum ferritin levels will detect the majority of patients who will be clinically affected and may detect other clinically significant disease in patients who do not have hemochromatosis genotypes. Because the ferritin level of the majority of adult homozygotes for HFE mutations does not rise over long periods of time, excluding subjects with serum ferritin levels less than or equal to 1000 μg/L should not result in missed opportunities for early treatment of patients who could benefit.
Prognostic implications of the European consensus for grading of bone marrow fibrosis in chronic idiopathic myelofibrosis
Authors: Vener Claudia , Fracchiolla Nicola Stefano , Gianelli Umberto , Calori Rossella , Radaelli Franca , Iurlo Alessandra , Caberlon Sabrina , Gerli Giancarla , Boiocchi Leonardo , Deliliers Giorgio Lambertenghi
Published: November 2007

Various clinical prognostic scoring systems (PSSs) have been suggested as means of selecting high-risk chronic idiopathic myelofibrosis (CIMF) patients at diagnosis. The WHO has recently proposed strict diagnostic criteria for CIMF, and the European consensus for bone marrow fibrosis (BMF) grading recommends 4 classes. It has been suggested that BMF grading may play a prognostic role in CIMF, but it has never been compared with the other PSSs in the same patients. We tested a prognostic model for overall survival (OS) based on the WHO criteria and BMF grading in 113 consecutive patients with chronic myeloproliferative disorders (98 with CIMF and 15 with postpolycythemic myelofibrosis), and compared the findings with those of PSSs. The results showed that our model is significantly associated with different OSs and, unlike the other PSSs, clearly discriminates the OS of intermediate- and high-risk patients.
The Firegoose: two-way integration of diverse data from different bioinformatics web resources with desktop applications
Authors: Bare J Christopher , Shannon Paul T , Schmid Amy K , Baliga Nitin S
Published: November 2007

Background

Information resources on the World Wide Web play an indispensable role in modern biology. But integrating data from multiple sources is often encumbered by the need to reformat data files, convert between naming systems, or perform ongoing maintenance of local copies of public databases. Opportunities for new ways of combining and re-using data are arising as a result of the increasing use of web protocols to transmit structured data.

Results

The Firegoose, an extension to the Mozilla Firefox web browser, enables data transfer between web sites and desktop tools. As a component of the Gaggle integration framework, Firegoose can also exchange data with Cytoscape, the R statistical package, Multiexperiment Viewer (MeV), and several other popular desktop software tools. Firegoose adds the capability to easily use local data to query KEGG, EMBL STRING, DAVID, and other widely-used bioinformatics web sites. Query results from these web sites can be transferred to desktop tools for further analysis with a few clicks.

Firegoose acquires data from the web by screen scraping, microformats, embedded XML, or web services. We define a microformat, which allows structured information compatible with the Gaggle to be embedded in HTML documents.

We demonstrate the capabilities of this software by performing an analysis of the genes activated in the microbe Halobacterium salinarum NRC-1 in response to anaerobic environments. Starting with microarray data, we explore functions of differentially expressed genes by combining data from several public web resources and construct an integrated view of the cellular processes involved.

Conclusion

The Firegoose incorporates Mozilla Firefox into the Gaggle environment and enables interactive sharing of data between diverse web resources and desktop software tools without maintaining local copies. Additional web sites can be incorporated easily into the framework using the scripting platform of the Firefox browser. Performing data integration in the browser allows the excellent search and navigation capabilities of the browser to be used in combination with powerful desktop tools.
A SAGE-based screen for genes expressed in sub-populations of neurons in the mouse dorsal root ganglion
Authors: Bourane Steeve , Méchaly Ilana , Venteo Stéphanie , Garces Alain , Fichard Agnes , Valmier Jean , Carroll Patrick
Published: November 2007

Background

The different sensory modalities temperature, pain, touch and muscle proprioception are carried by somatosensory neurons of the dorsal root ganglia. Study of this system is hampered by the lack of molecular markers for many of these neuronal sub-types. In order to detect genes expressed in sub-populations of somatosensory neurons, gene profiling was carried out on wild-type and TrkA mutant neonatal dorsal root ganglia (DRG) using SAGE (serial analysis of gene expression) methodology. Thermo-nociceptors constitute up to 80 % of the neurons in the DRG. In TrkA mutant DRGs, the nociceptor sub-class of sensory neurons is lost due to absence of nerve growth factor survival signaling through its receptor TrkA. Thus, comparison of wild-type and TrkA mutants allows the identification of transcripts preferentially expressed in the nociceptor or mechano-proprioceptor subclasses, respectively.

Results

Our comparison revealed 240 genes differentially expressed between the two tissues (P < 0.01). Some of these genes, CGRP, Scn10a are known markers of sensory neuron sub-types. Several potential markers of sub-populations, Dok4, Crip2 and Grik1/GluR5 were further analyzed by quantitative RT-PCR and double labeling with TrkA,-B,-C, c-ret, parvalbumin and isolectin B4, known markers of DRG neuron sub-types. Expression of Grik1/GluR5 was restricted to the isolectin B4+ nociceptive population, while Dok4 and Crip2 had broader expression profiles. Crip2 expression was however excluded from the proprioceptor sub-population.

Conclusion

We have identified and characterized the detailed expression patterns of three genes in the developing DRG, placing them in the context of the known major neuronal sub-types defined by molecular markers. Further analysis of differentially expressed genes in this tissue promises to extend our knowledge of the molecular diversity of different cell types and forms the basis for understanding their particular functional specificities.
Factors associated with the appropriate use of preoperatory hospital stays: historical cohort study
Authors: Tamames Sonia , Perez Rubio Alberto , Castrodeza Sanz Javier , Canton Alvarez Maria Belen , Luquero Francisco J , Santos Sanz Sara , Lopez Encinar Placido , de la Torre Pardo Maria Paz , Gil Gonzalez Juan Manuel
Published: November 2007

Background

To ensure the highest efficiency, health services should be provided with the least possible complexity. The aim of this study is to quantify the degree of appropriateness in preoperatory hospital stays and to analyse those factors associated with a greater inappropriate use.

Methods

Historical cohort study. The histories of 440 hospitalised patients who underwent at least one surgical procedure were analysed. Data collection was carried out by doctors not involved in the services studied, following the Appropriateness Evaluation Protocol. A bivariate and multivariate analysis of the factors associated with the appropriateness of preoperatory stays was carried out.

Results

The mean number of days of preoperatory stay was 5.5 (SD 5.11), of which a mean number of 2.5 days were considered to be inappropriate (SD 4.11). The overall rate of inappropriateness was 45.2% (CI 95% 43.3–47.1). The multivariate analysis showed a positive association of the inappropriateness of the preoperatory stay with weekend days, programmed admission, hospital stays longer than 7 days, medical records incorrectly or incompletely documented and the age groups of 45–65 and the >65 with respect to the <45 age group. Sex and an incorrect or incomplete nursing register did not show such an association.

Conclusion

The inappropriate use of hospital stay during preoperatory care affects almost half the period and there are some risk determinants that could act as indicators at admission. In addition, the efficiency of care provision was found to vary greatly from the point of view of its appropriateness.
Using hospital discharge data for determining neonatal morbidity and mortality: a validation study
Authors: Ford Jane B , Roberts Christine L , Algert Charles S , Bowen Jennifer R , Bajuk Barbara , Henderson-Smart David J ,   the NICUS group
Published: November 2007

Background

Despite widespread use of neonatal hospital discharge data, there are few published reports on the accuracy of population health data with neonatal diagnostic or procedure codes. The aim of this study was to assess the accuracy of using routinely collected hospital discharge data in identifying neonatal morbidity during the birth admission compared with data from a statewide audit of selected neonatal intensive care (NICU) admissions.

Methods

Validation study of population-based linked hospital discharge/birth data against neonatal intensive care audit data from New South Wales, Australia for 2,432 babies admitted to NICUs, 1994–1996. Sensitivity, specificity and positive predictive values (PPV) with exact binomial confidence intervals were calculated for 12 diagnoses and 6 procedures.

Results

Sensitivities ranged from 37.0% for drainage of an air leak to 97.7% for very low birthweight, specificities all exceeded 85% and PPVs ranged from 70.9% to 100%. In-hospital mortality, low birthweight (≤1500 g), retinopathy of prematurity, respiratory distress syndrome, meconium aspiration, pneumonia, pulmonary hypertension, selected major anomalies, any mechanical ventilation (including CPAP), major surgery and surgery for patent ductus arteriosus or necrotizing enterocolitis were accurately identified with PPVs over 92%. Transient tachypnea of the newborn and drainage of an air leak had the lowest PPVs, 70.9% and 83.6% respectively.

Conclusion

Although under-ascertained, routinely collected hospital discharge data had high PPVs for most validated items and would be suitable for risk factor analyses of neonatal morbidity. Procedures tended to be more accurately recorded than diagnoses.
Phase II Trial of a Transplantation Regimen of Yttrium-90 Ibritumomab Tiuxetan and High-Dose Chemotherapy in Patients With Non-Hodgkin's Lymphoma
Authors: Krishnan Amrita , Nademanee Auayporn , Fung Henry C. , Raubitschek Andrew A. , Molina Arturo , Yamauchi Dave , Rodriguez Roberto , Spielberger Ricardo T. , Falk Peter , Palmer Joycelynne M. , Forman Stephen J.
Published: November 2007

Purpose

This phase II trial evaluated the safety and efficacy of combining yttrium-90 (90Y) ibritumomab tiuxetan with high-dose carmustine, cytarabine, etoposide, and melphalan (BEAM) and autologous stem-cell transplantation in patients with non-Hodgkin's lymphoma who were considered ineligible for total-body irradiation because of older age or prior radiotherapy.

Patients and Methods

Between May 2002 and January 2006, 14 days before autologous stem-cell transplantation, 41 patients with non-Hodgkin's lymphoma received standard-dose 90Y ibritumomab tiuxetan (14.8 MBq/kg [0.4 mCi/kg]) followed by high-dose BEAM.

Results

The median age was 60 years (range, 19 to 78 years), and the median number of previous therapies was two (range, one to six). Disease histologies were diffuse large B-cell (n = 20), mantle cell (n = 13), follicular (n = 4), and transformed lymphoma (n = 4). With a median follow-up of 18.4 months (range, 5.5 to 53.3 months) the estimated 2-year overall and progression-free survival were 88.9% (95% CI, 75.3% to 95.2%) and 69.8% (95% CI, 56.4% to 79.7%). The median time to WBC engraftment was 11 days (range, 9 to 26 days) and time to platelet engraftment was 12 days (range, 3 to 107 days). Adverse events were similar to those seen historically with high-dose BEAM alone, and included grade 3 or 4 pulmonary toxicity in 10 patients.

Conclusion

Adding 90Y ibritumomab tiuxetan to high-dose BEAM with autologous stem-cell transplantation is feasible and has a toxicity and tolerability profile similar to that observed with BEAM alone. Rates of progression-free survival seen in these patients are promising and warrant additional study.
Pax Americana or Multilateralism? Reflecting on the United States' Grand Strategic Vision of Hegemony in the Wake of the 11 September Attacks
Authors: Fakiolas Efstathios T. , Fakiolas Tassos
Published: November 2007

Since the disintegration of the Soviet Union, the United States has been presented with a unique structural opportunity to establish world.scale hegemony. But it was not until after the 11 September terrorist attacks that an American president explicitly set out, under the pretext of the .war on terror,. to pursue hegemony in the form of a Pax Americana, that is, to build a unipolar American security order. Since then, the opposition of the other great powers, mainly of the European Union and in particular of the French.German axis, has proved a powerful stumbling block. Today, in the light of upheavals in Iraq and the US leadership.s inability to deal efficiently with its overcommitment, Pax Americana can be said to come into effect only if Europe falls prey to decay and division or Washington materializes its designs for the construction of an antiballistic missile defense shield. Rather, the key to US hegemony is the establishment of a multipolar American.led international system.
The Permanent “Other”? Turkey and the Question of European Identity
Authors: Kösebalaban Hasan
Published: November 2007

So far the prospect of Turkey.s accession to the EU has been studied with exclusive reference to Turkey.s progress in meeting the Copenhagen criteria for membership. However, as the recent electoral success of anti.Turkish European political parties and politicians suggests, the issue now is less institutional than cultural. By problematizing European cultural minimalism as the main informant of anti.Turkish opposition, this essay turns the issue of Turkish membership upside down. While in Turkey religiosity does not appear to be a decisive factor in shaping perceptions vis.à.vis Europe, as seen in the massive electoral support given to the Islamist but pro.EU Justice and Development Party (AKP), there is a growing culturally rooted opposition against the idea of Turkish membership in Europe. Why is it that in Europe, which is generally considered behaviorally and attitudinally more secular than Turkey, one observes this opposition against the inclusion of its religious and cultural other? This essay locates the answer to this question in the context of a European common identity.building process in which Turkey has historically played the most decisive role. While rejecting the argument that Turkish.EU relations amount to a clash of civilizations, the essay argues that the process of membership is complicated by a clash of two conflicting definitions of what Europe is and should be. The essay claims that the Turkish side.s double demands of inclusion into Europe and recognition of its distinct cultural identity directly conflict with the minimalist discourse that Europe is the center of civilization into which Turkey is expected to assimilate. While sharing this view during its history of modernization, Turkey, particularly under the AKP government, has grown more self.confident regarding its civilizational authenticty, while remaining supportive of the membership idea. Most Turks now perceive Europe as a geographical zone of opportunity where multiple claims for civilizational authenticity are equally recognized. The essay concludes that resolving the Turkish question, and by extension the question of Europe.s Muslim minority, will be possible only through a new, multicivilizational vision of Europe that confronts the minimalist discourse. Such a vision will enable Europe to emerge as a global power as opposed to an introverted regional player.
The Crisis in Darfur
Authors: Miller Molly J.
Published: November 2007

While many cite the February 2003 outbreak of violence in the Darfur region of Sudan as the beginning of what a chorus of international actors are now calling genocide, the conflict in Darfur has quite complicated historical roots. This essay examines the regional, ideological, and historical factors that have helped form the modern Darfur states, focusing particularly on the rise of the Islamist movement in Khartoum. It asserts that understanding these factors is necessary to devise an effective international response to the current crisis in the Darfur region.
Experimental validation of non-linear multi-body railroad vehicle system algorithms
Authors: Pigorini F , Gugliotta A , Sinokrot T , Shabana A A
Published: November 2007

The current trend in railroad industry is the development of reliable non-linear computational dynamic algorithms that can be used in the simulations of vehicle behaviour under different operating conditions. Of similar importance, is the development of experimental models that can be used in the validation of the proposed numerical algorithms. The objective of this investigation is to examine the accuracy of the results obtained using different multi-body contact formulations by comparing these results with experimental results. The numerical results are obtained using two different multi-body contact formulations: the embedded constraint contact formulation and the quasi-elastic contact formulation; both are implemented in general purpose multi-body computer programs. The numerical results obtained using these two different methods are analysed and compared. These results are also compared with the test results of a bogie prototype that can be used with a roller rig built at Turin Polytechnic. The roller rig, which is designed to be used with full scale or reduced scale models, provides an efficient and economic way to validate the results of the computer algorithms. This roller rig, which can also be used to perform tests on bogies with different rail gauge and wheel base, has been designed using Jaschinski's scaling method. A bogie computer model based on the same dimensions and material properties of the Turin roller rig was developed using two different general purpose multi-body computer programs that employ the two different non-linear wheel/rail contact formulations and two different numerical algorithms for the automatic generation and solution of the system equations of motion. The results of the two different multi-body formulations used in this study show a good agreement. Furthermore, the results show that the bogie critical speed predicted using the computer simulations is very close to the one obtained using the roller rig.
Hydrothiolation of Unactivated Alkynes Catalyzed by Indium(III) Bromide
Authors: Yadav J S , Reddy B V Subba , Raju A , Ravindar K , Baishya Gakul
Published: November 2007

Indium(III) bromide is found to catalyze efficiently the hydrothiolation of unactivated alkynes with various thiols under mild conditions to produce the corresponding dithioacetals in excellent yields. However, addition of aromatic thiols on aromatic alkynes gave the β-vinyl sulfides in high yields. This new procedure offers significant advantages such as high conversions, short reaction times, and simplicity in operation.