bluuebunny/crossref_metadata_2025 huggingface dataset:
Catheter Ablation of Ventricular Tachycardia Induced by Injection of Acetylcholine in the Right Coronary Artery
Authors: ARIMOTO TAKANORI , WATANABE TETSU , NITOBE JOJI , KUBOTA ISAO
Published: April 2010

Ventricular Tachycardia Induced by Acetylcholine.  We report the case of a patient who suffered from early morning nonsustained ventricular tachycardia. Clinical ventricular tachycardia without coronary spasm was reproducibly induced only by injection of acetylcholine in the right coronary artery. A good pace mapping site with 30 ms early ventricular activity was present in the right ventricular free wall. After radiofrequency ablation based on electroanatomical mapping, the tachycardia could no longer be induced by intracoronary injection of acetylcholine. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1410‐1412, December 2010)
Concealed Automaticity From an Island of Atrial Myocardium Post Cavotricuspid Ablation
Authors: LE POLAIN DE WAROUX JEAN‐BENOIT , NATTEL STANLEY , DUBUC MARC , TALAJIC MARIO , MACLE LAURENT
Published: April 2010

Island of Atrial Myocardium Post Cavotricuspid Ablation.  We report the case of a patient with paroxysmal atrial fibrillation in whom 2 previous cavotricuspid isthmus (CTI) ablations were performed for recurrent type I counterclockwise atrial flutter. One year after the last CTI ablation, the patient underwent pulmonary vein isolation for AF and reassessment of conduction block in the CTI was performed during the procedure. While mapping the CTI, activations were documented within the CTI that were dissociated from both right atrial and ventricular activity during sinus rhythm and pacing maneuvers. This dissociated activity was confined to a region delimited by the 2 previous ablation lines, the tricuspid annulus and the inferior vena cava. These findings suggest that an island of atrial myocardium with automatic activity was created within the CTI by previous ablation lines. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1408‐1409, December 2010)
The Protozooplankton–Ichthyoplankton Trophic Link: An Overlooked Aspect of Aquatic Food Webs1
Authors: MONTAGNES DAVID J. S. , DOWER JOHN F. , FIGUEIREDO GISELA M.
Published: April 2010

ABSTRACT. Since the introduction of the microbial loop concept, awareness of the role played by protozooplankton in marine food webs has grown. By consuming bacteria, and then being consumed by metazooplankton, protozoa form a trophic link that channels dissolved organic material into the “classic” marine food chain. Beyond enhancing energy transfer to higher trophic levels, protozoa play a key role in improving the food quality of metazooplankton. Here, we consider a third role played by protozoa, but one that has received comparatively little attention: that as prey items for ichthyoplankton. For >100 years it has been known that fish larvae consume protozoa. Despite this, fisheries scientists and biological oceanographers still largely ignore protozoa when assessing the foodweb dynamics that regulate the growth and survival of larval fish. We review evidence supporting the importance of the protozooplankton–ichthyoplankton link, including examples from the amateur aquarium trade, the commercial aquaculture industry, and contemporary studies of larval fish. We then consider why this potentially important link continues to receive very little attention. We conclude by offering suggestions for quantifying the importance of the protozooplankton–ichthyoplankton trophic link, using both existing methods and new technologies.
Reflexivity and Objectivity in Anthropology and Journalism
Authors: Tett Gillian
Published: April 2010

Shirley Fiske and Niel Tashima are contributing editors of “Anthropology Works,” the AAA Committee on Practicing, Applied and Public Interest Anthropology column in Anthropology News.
Exposure to dental amalgam restorations in pregnant women
Authors: Lygre Gunvor Bentung , Björkman Lars , Haug Kjell , Skjærven Rolv , Helland Vigdis
Published: April 2010

Lygre GB, Björkman L, Haug K, Skjærven R, Helland V. Exposure to dental amalgam restorations in pregnant women. Community Dent Oral Epidemiol 2010; 38: 460–469. © 2010 John Wiley & Sons A/S

Abstract –  Objectives:  The Norwegian Mother and Child Cohort Study (MoBa) started in 1999 to identify environmental factors that could be involved in mechanisms leading to disease. Questions have been raised about potential risks to the fetus from prenatal exposure to mercury from amalgam fillings in pregnant women. The aim of the present study was to identify factors potentially associated with amalgam fillings in pregnant women participating in the Norwegian Mother and Child Cohort Study (MoBa). An additional aim was to obtain information about dental treatment in the cohort.

Methods:  Total of 67 355 pregnancies from the MoBa study were included in the present study. Information regarding age, education, smoking habits, alcohol consumption, weight, and height for the women was obtained from a questionnaire that was filled in at the 17th week of pregnancy. In another questionnaire, which was sent to all participants in the 30th week of pregnancy, the women reported types of dental treatment during pregnancy, total number of teeth, and number of teeth with amalgam fillings. The self‐assessed number of teeth and number of teeth with amalgam fillings were validated in an external sample of 97 women of childbearing age.

Results:  Odds ratio for having more than 12 teeth with amalgam fillings increased considerably with age. Other significant risk factors for having high exposure to amalgam were low education, high body mass index (BMI), and smoking during pregnancy. Women with the lowest levels of education had a twofold increased odds ratio of having more than 12 teeth filled with amalgam compared with women who had more than 4 years of university studies. According to the results from the validation of self‐assessed number of teeth with amalgam fillings, the information obtained was reliable.

Conclusion:  Age, education, smoking habits, and BMI were associated with amalgam exposure.
Effects of thymoquinone on isolated and cellular proteasomes
Authors: Cecarini Valentina , Quassinti Luana , Di Blasio Alessia , Bonfili Laura , Bramucci Massimo , Lupidi Giulio , Cuccioloni Massimiliano , Mozzicafreddo Matteo , Angeletti Mauro , Eleuteri Anna Maria
Published: April 2010

Thymoquinone, a naturally derived agent, has been shown to possess antioxidant, antiproliferative and proapoptotic activities. In the present study, we explored thymoquinone effects on the proteasomal complex, the major system involved in the removal of damaged, oxidized and misfolded proteins. In purified 20S complexes, subunit‐dependent and composition‐dependent inhibition was observed, and the chymotrypsin‐like and trypsin‐like activities were the most susceptible to thymoquinone treatment. U87 MG and T98G malignant glioma cells were treated with thymoquinone, and 20S and 26S proteasome activity was measured. Inhibition of the complex was evident in both cell lines, but predominantly in U87 MG cells, and was accompanied by accumulation of ubiquitin conjugates. Accumulation of p53 and Bax, two proteasome substrates with proapoptotic activity, was observed in both cell lines. Our results demonstrate that thymoquinone induces selective and time‐dependent proteasome inhibition, both in isolated enzymes and in glioblastoma cells, and suggest that this mechanism could be implicated in the induction of apoptosis in cancer cells.
Highly site‐selective stability increases by glycosylation of dihydrofolate reductase
Authors: Tey Lai‐Hock , Loveridge E. Joel , Swanwick Richard S. , Flitsch Sabine L. , Allemann Rudolf K.
Published: April 2010

Post‐translational glycosylation is one of the most abundant forms of covalent protein modification in eukaryotic cells. It plays an important role in determining the properties of proteins, and stabilizes many proteins against thermal denaturation. Protein glycosylation may establish a surface microenvironment that resembles that of unglycosylated proteins in concentrated solutions of sugars and other polyols. We have used site‐directed mutagenesis to introduce a series of unique cysteine residues into a cysteine‐free double mutant (DM, C85A/C152S) of dihydrofolate reductase from Escherichia coli (EcDHFR). The resulting triple mutants, DM‐N18C, DM‐R52C, DM‐D87C and DM‐D132C EcDHFR, were alkylated with glucose, N‐acetylglucosamine, lactose and maltotriose iodoacetamides. We found little effect on catalysis or stability in three cases. However, when DM‐D87C EcDHFR is glycosylated, stability is increased by between 1.5 and 2.6 kcal·mol−1 in a sugar‐dependent manner. D87 is found in a hinge region of EcDHFR that loses structure early in the thermal denaturation process, whereas the other glycosylation sites are found in regions involved in the later stages of temperature‐induced unfolding. Glycosylation at this site may improve the stability of EcDHFR by protecting a region of the enzyme that is particularly prone to denaturation.
Insulin like growth factor‐1‐induced phosphorylation and altered distribution of tuberous sclerosis complex (TSC)1/TSC2 in C2C12 myotubes
Authors: Miyazaki Mitsunori , McCarthy John J. , Esser Karyn A.
Published: April 2010

Insulin like growth factor‐1 (IGF‐1) is established as an anabolic factor that can induce skeletal muscle growth by activating the phosphoinositide 3‐kinase/Akt/mammalian target of rapamycin (mTOR) pathway. Although this signaling pathway has been the subject of much study, the molecular mechanisms linking IGF‐1 binding to mTOR activation remain poorly defined in muscle. The present study aimed to test the hypothesis that IGF‐1 activation of mTOR in C2C12 myotubes requires a phosphorylation‐dependent, altered distribution of the tuberous sclerosis complex (TSC)1/TSC2 complex from the membrane to the cytosol. We found that IGF‐1 treatment does not affect complex formation between TSC1 and TSC2, but rather IGF‐1 induces an altered distribution of the TSC1/TSC2 complex in C2C12 myotubes. In response to IGF‐1 treatment, there was a relative redistribution of the TSC1/TSC2 complex, composed of TSC1 and phosphorylated TSC2, from the membrane to the cytosol. IGF‐1‐stimulated TSC1/TSC2 phosphorylation and redistribution were completely prevented by the phosphoinositide 3‐kinase inhibitor wortmannin, but were not with the downstream mTOR inhibitor, rapamycin. When a nonphosphorylatable form of TSC2 (S939A) was overexpressed, phosphorylation‐dependent binding of the scaffold protein 14‐3‐3 to TSC2 was diminished and no redistribution of the TSC1/TSC2 complex was observed after IGF‐1 stimulation. These results indicate that TSC2 phosphorylation in response to IGF‐1 treatment is necessary for the altered distribution of the TSC1/TSC2 complex to the cytosol. We suggest that this translocation is likely critical for mTOR activation by dissociating the interaction between the GTPase activating protein activity of the TSC1/TSC2 complex and its downstream target, Ras homolog enriched in brain.

Structured digital abstract

MINT‐7712277, MINT‐7712399: Tsc2 (uniprotkb:Q61037), S6K1 (uniprotkb:Q8BSK8) and Tsc1 (uniprotkb:Q9EP53) colocalize (MI:0403) by cosedimentation through density gradient (MI:0029)

MINT‐7712211, MINT‐7712236, MINT‐7712313, MINT‐7712323: Tsc1 (uniprotkb:Q9EP53) physically interacts (MI:0915) with Tsc2 (uniprotkb:Q61037) by anti bait coimmunoprecipitation (MI:0006)

MINT‐7712377: 14‐3‐3 beta (uniprotkb:Q9CQV8) physically interacts (MI:0914) with Tsc1 (uniprotkb:Q9EP53) and Tsc2 (uniprotkb:Q61037) by pull down (MI:0096)

MINT‐7712483: Tsc1 (uniprotkb:Q9EP53) and Tsc2 (uniprotkb:Q61037) colocalize (MI:0403) by cosedimentation through density gradient (MI:0029)

MINT‐7712436: TSC2 (uniprotkb:P49815) physically interacts (MI:0915) with TSC1 (uniprotkb:Q92574) by anti bait coimmunoprecipitation (MI:0006)

MINT‐7712451: Tsc1 (uniprotkb:Q9EP53), Rheb (uniprotkb:Q921J2) and Tsc2 (uniprotkb: Q61037) colocalize (MI:0403) by cosedimentation through density gradient (MI:0029)
Nuclear factor TDP‐43 can affect selected microRNA levels
Authors: Buratti Emanuele , De Conti Laura , Stuani Cristiana , Romano Maurizio , Baralle Marco , Baralle Francisco
Published: April 2010

TDP‐43 has recently been described as the major component of the inclusions found in the brain of patients with a variety of neurodegenerative diseases, such as frontotemporal lobar degeneration and amyotrophic lateral sclerosis. TDP‐43 is a ubiquitous protein whose specific functions are probably crucial to establishing its pathogenic role. Apart from its involvement in transcription, splicing and mRNA stability, TDP‐43 has also been described as a Drosha‐associated protein. However, our knowledge of the role of TDP‐43 in the microRNA (miRNA) synthesis pathway is limited to the association mentioned above. Here we report for the first time which changes occur in the total miRNA population following TDP‐43 knockdown in culture cells. In particular, we have observed that let‐7b and miR‐663 expression levels are down‐ and upregulated, respectively. Interestingly, both miRNAs are capable of binding directly to TDP‐43 in different positions: within the miRNA sequence itself (let‐7b) or in the hairpin precursor (miR‐663). Using microarray data and real‐time PCR we have also identified several candidate transcripts whose expression levels are selectively affected by these TDP‐43–miRNA interactions.
Trauma, Gender Reassignment, and Penile Augmentation
Authors: Ralph David , Gonzalez-Cadavid Nestor , Mirone Vincenzo , Perovic Sava , Sohn Michael , Usta Mustafa , Levine Laurence
Published: April 2010

Introduction

Penile trauma is common with standard management options. Gender reassignment techniques are rapidly changing and penile augmentation remains a controversial topic. Consequently, there is need for a state-of-the-art information in this area.

Aim

This study aims to develop an evidence-based state-of-the-art consensus report on the management of penile trauma, gender, reassignment and penile augmentation.

Methods

The study provides state-of-the-art knowledge regarding the prevalence, etiology, medical and surgical management of penile trauma, gender reassignment and penile augmentation, representing the opinion of leading experts developed in a consensus process over a 2-year period.

Main Outcome Measures

Expert opinion was based on grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate.

Conclusions

Penile fracture should be managed surgically. Information should be readily available to patients to help them decide the surgical technique desired for gender reassignment and to justify any form of penile augmentation.
Polymorphism of glutathione S‐transferase M1 and T1 gene LOCI in COPD
Authors: Mehrotra S. , Sharma A. , Kumar S. , Kar P. , Sardana S. , Sharma J. K.
Published: April 2010

Chronic obstructive pulmonary disease (COPD) is a complex combination of signs and symptoms in patients with chronic bronchitis and emphysema, diseases that largely result from cigarette smoking. A little information is available for the underlying molecular mechanisms that are responsible for its occurrence. Polymorphisms in genes of xenobiotics metabolizing enzymes are expected to modulate individual responses to genotoxic carcinogens. Present study was a case–control study of COPD patients and healthy controls. Genetic polymorphisms of GSTM1 and GSTT1 genes in 50 COPD patients and 50 healthy controls were investigated using multiplex polymerase chain reaction–restriction fragment length polymorphism techniques to determine whether polymorphisms of these genes are linked to genetic susceptibility to COPD. All subjects were males and smokers. The frequency of GSTM1 homozygous null genotype was 28.0% in COPD cases when compared with controls (32.0%). The difference was not significant showing that risk of COPD was not associated with the GSTM1 null genotypes. The frequencies of homozygous null genotypes of GSTT1 were significantly higher in COPD cases as compared with controls (40% versus 14.0%) suggesting that the theta‐glutathione S‐transferases null genotype may be associated with the susceptibility to COPD. No significant differences were observed when comparisons were performed according to severity of disease and smoking for GSTM1 and GSTT1. It was also observed that COPD developed in the early age and with a shorter pack‐year history in Indian population.
Climatic factors affecting the occurrence of cloudy stain on the fruit skin of ‘Triumph’ Japanese persimmon
Authors: Reig C. , Mesejo C. , Martínez‐Fuentes A. , Agustí M.
Published: April 2010

Cloudy stain is a physiological disorder of the Japanese persimmon blemishing the skin and causing a great reduction of fruit quality, thus decreasing its commercial value. The stain starts at or just prior to the fruit colour‐break stage, coinciding with the presence of cuticular cracks which increase cuticle water permeability and expose subepidermal cells to air and water, causing oxidation of polyphenol substances of large skin areas that turn almost black. The incidence of the disorder examined over four consecutive years in two growing areas of Spain revealed significant differences from year to year, between areas and even the tree face examined. The data consistently showed that cooler groves and fruit located on the northern face of the canopy were more prone to develop the stain. During the 4 years of the study, the average daily minimum temperature of a period of 15–25 days prior to the onset of staining followed the same order as the yearly staining rate, and accumulated hours below 13°C correlated significantly with the percentage of fruit starting the disorder. No relationship was found between the time‐course of relative humidity (RH) and the onset of staining, but once the stain started the lower RH resulted in the lower percentage of affected fruit. Dew point, wind speed, rainfall and evapotranspiration did not correlate either with the onset of staining or with its incidence. Rind of cloudy‐stained fruit had higher concentration of N, K, Mg and Fe and lower concentration of Ca than that of healthy fruit, but it is not the cause of the disorder. Accordingly, we conclude that cloudy stain of Japanese persimmon starts after a period of low temperature (≤ 13°C) and, afterwards, RH is responsible for its development and severity.
A phylogeny of Vetigastropoda and other “archaeogastropods”: re‐organizing old gastropod clades
Authors: Aktipis Stephanie W. , Giribet Gonzalo
Published: April 2010

Abstract.The phylogenetic relationships among the “archaeogastropod” clades Patellogastropoda, Vetigastropoda, Neritimorpha, and Neomphalina are uncertain; the phylogenetic placement of these clades varies across different analyses, and particularly among those using morphological characteristics and those relying on molecular data. This study explores the relationships among these groups using a combined analysis with seven molecular loci (18S rRNA, 28S rRNA, histone H3, 16S rRNA, cytochromecoxidase subunit I [COI], myosin heavy‐chain type II, and elongation factor‐1α [EF‐1α]) sequenced for 31 ingroup taxa and eight outgroup taxa. The deep evolutionary splits among these groups have made resolution of stable relationships difficult, and so EF‐1α and myosin are used in an attempt to re‐examine these ancient radiation events. Three phylogenetic analyses were performed utilizing all seven genes: a single‐step direct optimization analysis using parsimony, and two‐step approaches using parsimony and maximum likelihood. A single‐step direct optimization parsimony analysis was also performed using only five molecular loci (18S rRNA, 28S rRNA, histone H3, 16S rRNA, and COI) in order to determine the utility of EF‐1α and myosin in resolving deep relationships. In the likelihood and POY optimal phylogenetic analyses, Gastropoda, Caenogastropoda, Neritimorpha, Neomphalina, and Patellogastropoda were monophyletic. Additionally, Neomphalina and Pleurotomariidae fell outside the remaining vetigastropods, indicating the need for further investigation into the relationship of these groups with other gastropods.
The silkworm homolog of Methoprene‐tolerant (Met) gene reveals sequence conservation but function divergence
Authors: Li Zhi‐Qing , Cheng Dao‐Jun , Wei Ling , Zhao Ping , Shu Xu , Tang Lin , Xiang Zhong‐Huai , Xia Qing‐You
Published: April 2010

Abstract  Methoprene‐tolerant (Met) gene has been found to be involved in juvenile hormone (JH) action in insects. Herein, we isolated a silkworm (Bombyx mori) homolog of Met gene from Drosophila melanogaster using bio‐informatics analysis and rapid amplification of cDNA ends – polymerase chain reaction method, and defined it as BmMet. The full‐length cDNA of BmMet gene consists of 1 917 nucleotides and includes a 1 368 bp of open reading frame for a deduced protein of 455 amino acids. All deduced protein sequences from Met genes in B. mori and other surveyed insects contain four typical domains of bHLH, PAS‐A, PAS‐B and PAC, highlighting a high sequence conservation of Met genes during insect evolution. Also, genomic structure and phylogenic analysis suggested that Met in both B. mori and Drosophila species may originate from an ancestor gene with gce, another member of bHLH‐PAS family, via gene duplication. In addition, BmMet was detected in all surveyed tissues and throughout the whole life of silkworm at transcriptional levels. Furthermore, silkworm individuals with RNAi silencing of BmMet gene in the early stage of the fourth instar larvae could molt normally and pupate successfully. This result was different from the observation in T. castaneum but similar to that in D. melanogaster after Met knockdown, revealing that the action mode of Met in B. mori and D. melanogaster should be divergent with that in other insect species.
Spatial structure of X-ray filaments in SN 1006
Authors: Morlino G. , Amato E. , Blasi P. , Caprioli D.
Published: April 2010

The theory of non-linear diffusive shock acceleration (NLDSA) predicts the formation of a precursor upstream of the shock, where accelerated particles diffuse and induce magnetic field amplification (MFA) through streaming instability. The non-detection of this precursor in X-rays in Chandra observations of the north-eastern region of SN 1006 (G329.6+14.6) led the authors of some previous work to impose an upper limit to the X-ray emission generated by accelerated electrons diffusing in this precursor, at an emissivity level of <1.5 per cent of the emission from the downstream region. This has been used as an argument against Fermi acceleration at this shock. Here, we calculate the spectrum and spatial distribution of accelerated particles in SN 1006 and show that Chandra results (including more recent data) are in perfect agreement with the predictions of NLDSA suggesting efficient particle acceleration and MFA upstream of the shock by a factor of ∼10.
Continuum and line modelling of discs around young stars — I. 300 000 disc models for HERSCHEL/GASPS
Authors: Woitke P. , Pinte C. , Tilling I. , Ménard F. , Kamp I. , Thi W.-F. , Duchêne G. , Augereau J.-C.
Published: April 2010

We have combined the thermo-chemical disc code ProDiMo with the Monte Carlo radiative transfer code MCFOST to calculate a grid of ∼300 000 circumstellar disc models, systematically varying 11 stellar, disc and dust parameters including the total disc mass, several disc shape parameters and the dust-to-gas ratio. For each model, dust continuum and line radiative transfer calculations are carried out for 29 far-infrared, sub-mm and mm lines of [Oi], [Cii], 12CO and o/p-H2O under five inclinations. The grid allows us to study the influence of the input parameters on the observables, to make statistical predictions for different types of circumstellar discs and to find systematic trends and correlations between the parameters, the continuum fluxes and the line fluxes. The model grid, comprising the calculated disc temperature and chemical structures, the computed spectral energy distributions, line fluxes and profiles, will be used in particular for the data interpretation of the HERSCHEL open time-key program GASPS. The calculated line fluxes show a strong dependence on the assumed ultraviolet excess of the central star and on the disc flaring. The fraction of models predicting [Oi] and [Cii] fine-structure lines fluxes above HERSCHEL/PACS and SPICA/SAFARI detection limits is calculated as a function of disc mass. The possibility of deriving the disc gas mass from line observations is discussed.
A Religion in Death Throes: How Secrecy Undermines the Survival of a Crypto Shin Buddhist Tradition in Japan Today
Authors: Chilson Clark
Published: April 2010

Although we know that religions decline and die, we know little about what causes them to do so. This article introduces a form of underground or crypto Pure Land Buddhism that has been practiced in secret for hundreds of years in Japan but in the past 50 years has declined rapidly and may be nearing extinction. It is argued that one of the factors that is undermining its survival is its secrecy. The article is intended to contribute to our knowledge on what can cause the decline of a religion and to our understanding of secrecy in religion, which scholars have generally regarded as providing religions benefits such as attracting new members, valorizing doctrine, and enhancing authority.
Usage of the Polyphenylene Oxide Dosimeter to Measure Annual Solar Erythemal Exposures
Authors: Schouten Peter W. , Parisi Alfio V. , Turnbull David J.
Published: April 2010

Poly (2, 6‐dimethyl‐1, 4‐phenylene oxide) (PPO) film is a useful dosimetric tool for measuring solar UV in underwater and terrestrial environments. However, little is known about how the response of PPO changes with fluctuations in atmospheric ozone and also to seasonal variations. To resolve this issue this article presents a series of long‐term in‐air solar erythemal response measurements made over a year from 2007 to 2008 with PPO. This data showed that the PPO dose response varies with modulations of the solar spectrum resulting from changes in season and atmospheric ozone. From this, it was recommended that PPO only be calibrated in the season in which it is to be used at the same time as measurements were being made in the field. Extended solar UV measurements made by PPO with a neutral density filter (NDF) based on polyethylene are also detailed. These measurements showed that the lifetime of PPO could be extended by 5 days before saturation. As the dynamic range for PPO is known to be 5 days during summer at a sub‐tropical location, the advantage of using the NDF is that half the number of dosimeters is needed to be fabricated and measured before and after exposure.
Effect of CO2 Laser Radiation on Physiological Tolerance of Wheat Seedlings Exposed to Chilling Stress
Authors: Chen Yi‐Ping , Jia Jing‐Fen , Yue Ming
Published: April 2010

To determine the effect of CO2 laser pretreatment of wheat seeds on the physiological tolerance of seedlings to chilling stress, wheat seeds were exposed to CO2 laser radiation for 300 s. After being cultivated for 48 h at 25°C, the wheat seedlings were subjected to chilling stress for 24 h. Selected physiological and biochemical parameters were measured in 6‐day‐old seedlings. We observed that chilling stress enhanced the concentrations of malondialdehyde and oxidized glutathione while decreasing the activities of nitric oxide synthase, catalase, peroxidase, superoxide dismutase and the concentrations of nitric oxide and glutathione in the wheat leaves compared with controls. When the chilling stress was preceded by CO2 laser irradiation, the concentrations of malondialdehyde and oxidized glutathione were decreased while the activities of nitric oxide synthase, catalase, peroxidase, superoxide dismutase and the concentrations of nitric oxide and glutathione increased. Furthermore, chilling stress decreased the biomass, biophoton intensity and GHS/GSSG ratios of seedlings while these parameters increased when the seedlings were treated with CO2 laser irradiation prior to the chilling stress. The results suggest that a suitable dose of CO2 laser stimulation can enhance the physiological tolerance of wheat seedlings to chilling stress.
Risk of Pregnancy‐Related Hypertension Within 5 Years of Exposure to Drinking Water Contaminated With Escherichia coli O157:H7
Authors: Moist Louise , Sontrop Jessica M. , Garg Amit X. , Clark William F. , Suri Rita S , Gratton Robert , Salvadori Marina , Nevis Immaculate , Macnab Jennifer J.
Published: April 2010

J Clin Hypertens(Greenwich). 2010;12:613–620. © 2010 Wiley Periodicals, Inc.

The authors evaluated the risk for pregnancy‐related hypertension among previously healthy women who conceived within 5 years of exposure to drinking water contaminated with Escherichia coli O157.H7 in Walkerton, Canada (2000). Chronic hypertension was defined as systolic/diastolic blood pressure ≥140/90 mm Hg before 20 weeks gestation; gestational hypertension was defined as new onset systolic/diastolic blood pressure ≥140/90 mm Hg ≥20 weeks gestation. The incidence of hypertension was compared between women who were asymptomatic during the outbreak to those who experienced acute gastroenteritis. Blood pressure data were available for 135 of 148 eligible pregnancies. The adjusted relative risks for chronic and gestational hypertension were 1.5 (95% confidence interval [CI]: 0.3–7.7) and 1.0 (95% CI: 0.4–2.5), respectively. Mean arterial pressure before 20 weeks gestation was 2.7 mm Hg higher in women who had acute gastroenteritis (95% CI: 0.05–5.4). A trend toward higher chronic hypertension and mean arterial pressure in early pregnancy was observed among women who experienced gastroenteritis after exposure to bacterially‐contaminated drinking water.
On-Line Identification and Control of Part-Preparation and Fixturing Errors in Arc Welding
Authors: Nagarajan S. , Wikle H. C. , Chin B. A.
Published: April 2010

Sensing elements need to be incorporated in robotic welding systems to enable the robot to perceive and adapt to on-line variations occurring in the welding process. In this work, infrared thermal imaging techniques have been used to track variations produced by inadequate control during the joint preparation and fixturing stages. Variations in two joint parameters, gap and position, were studied. Changes in these parameters were found to have peculiar effects on the surface temperature distributions. The observed effects were used to develop quantitative error signals. These error signals were then used to measure the joint gaps and joint-torch offsets in real-time. The joint torch offset error signal was successfully used to control an initial error in joint position during real-time welding.
Distortion in the Thermal Field Around Inserted Thermocouples in Experimental Interfacial Studies—Part 3: Experimental and Numerical Verification
Authors: Attia M. H. , Kops L.
Published: April 2010

Using the electrostatic analog method, the authors have investigated in earlier publications the disturbance in a two-dimensional steady temperature field due to the presence of a thermocouple void and the measurement error due to the heat transfer along the thermocouple leads. Those results pertaining to a perfectly insulated thermocouple void are verified in the present study, using the finite element method and a well-controlled experiment in which the thermocouple hole is scale-modelled. The numerical and experimental results are found to be in good agreement with those predicted by the electrostatic analog method. The numerical solution of the case in which the thermocouple leads act as heat sink indicated the inherent deficiency of the analog method in modelling the path of the heat flow lines from the zone surrounding the thermocouple hole into the leads. The previously published data on the effect of the heat losses through the leads on the temperature measurement error are therefore revised. The characteristic features of the disturbed temperature field, in terms of its symmetry, the existence of neutral points and the sinusoidal variation of the temperature along the periphery of the hole are quantitatively confirmed.
Finite Element Analysis of the Axisymmetric Upsetting Process Using the Deformation Theory of Plasticity
Authors: Vertin K. D. , Majlessi S. A.
Published: April 2010

The deformation theory of plasticity is extended to the analysis of bulk metal forming problems. An elastic-plastic finite element formulation is developed and used to simulate solid cylinder and ring upsetting processes. The intent of this analysis is to demonstrate that the deformation theory yields solutions equivalent to the incremental theory, and requires less computation time. Predicted results are compared with published incremental finite element solutions and experimental measurements. Deformation theory results are in agreement with published data for many forming conditions. The performance of the formulation gradually degraded with increasing deformation and friction, and possible causes for this behavior are discussed.
A Failure Isolation Strategy for Thermofluid System Diagnostics
Authors: Wagner J. , Shoureshi R.
Published: April 2010

The application of microprocessor-based diagnostic strategies to industrial processes provides improved system reliability while reducing maintenance costs. The prompt detection and classification of system anomalies enables reduced troubleshooting by technicians and minimizes the misclassification of system degradations. In this paper, an experimental-based multiple hypothesis failure isolation scheme for small-scale thermofluid systems is presented. The proposed classification strategy combines dynamic modeling, control theory, multivariate statistics, and pattern recognition to develop a methodology that may be tailored for a variety of applications. The primary goal of this study is the reduction of modeling activities associated with the set of hypothesized failure modes. The overall performance of the isolation scheme is investigated for a series of experimentally simulated heat pump failures.
System Identification Using ARMA Modeling and Neural Networks
Authors: Pramod B. R. , Bose S. C.
Published: April 2010

Stochastic system identification is an important tool for control of discrete dynamic systems. Among the modeling strategies developed for this purpose, Auto Regressive Moving Average (ARMA for discrete systems) models offer an accurate identification technique. The disadvantage with these models are that they are extremely complicated to implement on-line, especially for nonlinear time-variant systems. This paper utilizes a Neural Network structure for identification of stochastic processes and tracks system dynamics by on-line adjustments of network parameters. Neural dynamics is based on impulse responses and an iterative learning algorithm is derived using conventional principles of gradient descent and backpropagation. The learning algorithm is analyzed and shown to be fast and accurate in the identification of parameters for stochastic processes in both time-invariant and time-variant cases.
Heat Transfer Augmentation Downstream of Rows of Various Dimple Geometries on the Suction Side of a Gas Turbine Airfoil
Authors: Dees Jason E. , Bogard David G. , Bunker Ronald S.
Published: April 2010

Heat transfer coefficients were measured downstream of a row of shaped film cooling holes, as well as elliptical, diffuser, and teardrop shaped dimples, simulating depressions due to film coolant holes of different shapes. These features were placed on the suction side of a simulated gas turbine vane. The dimples were used as approximations to film cooling holes after the heat transfer levels downstream of active fan shaped film cooling holes was found to be independent of film cooling. The effects of the dimples were tested with varying approach boundary layers, freestream turbulence intensity, and Reynolds numbers. For the case of an untripped (transitional) approach boundary layer, all dimple shapes caused approximately a factor of 2 increase in heat transfer coefficient relative to the smooth baseline condition due to the dimples effectively causing boundary layer transition downstream. The exact augmentation varied depending on the dimple geometry: diffuser shapes causing the largest augmentation and teardrop shapes causing the lowest augmentation. For tripped (turbulent boundary layer) approach conditions, the dimple shapes all caused the same 20% augmentation relative to the smooth tripped baseline. The already turbulent nature of the tripped approach flow reduces the effect that the dimples have on the downstream heat transfer coefficient.
Computational Modeling of Tip Heat Transfer to a Superscale Model of an Unshrouded Gas Turbine Blade
Authors: Tang Brian M. T. , Palafox Pepe , Cheong Brian C. Y. , Oldfield Martin L. G. , Gillespie David R. H.
Published: April 2010

Control of over-tip leakage flow between turbine blade tips and the stationary shroud is one of the major challenges facing gas turbine designers today. The flow imposes large thermal loads on unshrouded high pressure (HP) turbine blades and is significantly detrimental to turbine blade life. This paper presents results from a computational study performed to investigate the detailed blade tip heat transfer on a sharp-edged, flat tip HP turbine blade. The tip gap is engine representative at 1.5% of the blade chord. Nusselt number distributions on the blade tip surface have been obtained from steady flow simulations and are compared with experimental data carried out in a superscale cascade, which allows detailed flow and heat transfer measurements in stationary and engine representative conditions. Fully structured, multiblock hexahedral meshes were used in the simulations performed in the commercial solver FLUENT. Seven industry-standard turbulence models and a number of different tip gridding strategies are compared, varying in complexity from the one-equation Spalart–Allmaras model to a seven-equation Reynolds stress model. Of the turbulence models examined, the standard k-ω model gave the closest agreement to the experimental data. The discrepancy in Nusselt number observed was just 5%. However, the size of the separation on the pressure side rim was underpredicted, causing the position of reattachment to occur too close to the edge. Other turbulence models tested typically underpredicted Nusselt numbers by around 35%, although locating the position of peak heat flux correctly. The effect of the blade to casing motion was also simulated successfully, qualitatively producing the same changes in secondary flow features as were previously observed experimentally, with associated changes in heat transfer with the blade tip.
Variational Method for Nonconservative Problems
Authors: Dubey R. N.
Published: April 2010

It is shown that the Ritz variational method can be applied to nonconservative problems provided the admissible velocity satisfies not only the geometric boundary condition but also a work condition on the part of the boundary surface where traction and traction rate are prescribed. It is further found that the modified variational principle can also be applied to nonconservative systems for which it is possible to construct an adjoint system. The principle is expected to be useful for application to a wide class of problems, including those encountered in connection with hydrodynamic and hydromagnetic stability investigation.
Moire´-Holographic Technique for Three-Dimensional Stress Analysis
Authors: Sciammarella C. A. , Di Chirico G. , Chang T.-Y.
Published: April 2010

The moire´ method is combined with hologram interferometry to obtain the three displacements of an arbitrarily deformed plane in the three-dimensional space. Double beam interference patterns are utilized. The interfering beams are obtained from the diffraction patterns of a grating printed in the analyzed plane. The in-plane and the out-of-plane displacements are measured in separate steps and yield separate patterns. The patterns are generated by double exposure and observed by a wave front reconstruction process. The experimental results included in the paper show a good agreement with theoretical results, proving the feasibility of the proposed technique.
Stokes Flow in an Annular Region
Authors: Liron N. , Gillis J.
Published: April 2010

We consider the steady-state parallel flow of a homogeneous viscous liquid in the annular region between concentric cylinders at low Reynolds numbers. The linearized equations are solved by expansions in terms of suitable eigenfunctions. The main features of the flow, including velocity profiles, are calculated numerically.
Stress Analysis for a Nonlinear Viscoelastic Cylinder With Ablating Inner Surface
Authors: Ting E. C.
Published: April 2010

An approximate constitutive equation for nonlinear viscoelastic incompressible materials under small finite deformation and for short time ranges has been derived by Huang and Lee [1]. The resulting equation is applied to solve the problem of a pressurized viscoelastic hollow cylinder bonded to an elastic easing. This problem is of notable technical interest in solid propellant stress analysis, since it is a close model to represent a cylindrical propellant grain in a solid fuel rocket under firing condition. The method used by Huang and Lee is appropriate for numerical calculations when the boundaries of the cylinder are nonablating. To consider one step closer to the real situation, the inner surface is often assumed to be ablating and hence time-dependent. It is then the purpose of the present paper to extend the analysis to a cylinder with moving inner surface.
Flow in Locally Constricted Tubes at Low Reynolds Numbers
Authors: Lee Jen-Shih , Fung Yuan-Cheng
Published: April 2010

With an objective to understand arteriosclerosis, the blood flow in a circular cylindrical tube with a local constriction is analyzed. Numerical results are presented for the streamlines and the distributions of velocity, pressure, vorticity, and shear stress in the Reynolds number range 0–25. These results have applications to other fluid-mechanical problems such as gauges for velocity measurements, etc.
Application of the Tau-Decomposition Method to Dynamical Systems Subjected to Retarded Follower Forces
Authors: Hsu C. S.
Published: April 2010

A method of stability analysis called the τ-decomposition method is briefly described first. It is then applied to a two-degrees-of-freedom model. The effect of different amounts of damping and the effect of different amounts of deviation from tangency for the follower forces are taken into consideration. The results are given in a series of graphs showing the regions of asymptotic stability in the force amplitude-time delay parameter plane. One important result is that when the time delay is small and the force is compressive, the presence of a very small time delay could be enough to cause instability if the damping is small. The results obtained here for the case of zero damping agree with those given in [10], which is restricted to the undamped case, and also utilized a different method. The application given in this paper clearly demonstrates the effectiveness and simplicity of the τ-decomposition method and its superiority over other methods for dealing with retarded dynamical systems of this kind.
Determination of Gyroscopic Drifts Associated With Angular Support Motions
Authors: Wenglarz R. A.
Published: April 2010

A previously proposed systematic approach for the analysis of gyroscopic drifts associated with angular support motions is further developed. For a wide range of support motions, the problem of determination of drifts is reduced to the evaluation of four integrals. The validity of the theory is tested by applying it to a gyroscope experiencing a constant rate about a fixed line and comparing the resulting predictions with those of digital computer solutions of the exact differential equations of motion, and formulas relating steady drifts to system parameters are presented.
The Influence of Large Deflections on the Behavior of Rigid-Plastic Cylindrical Shells Loaded Impulsively
Authors: Jones Norman
Published: April 2010

A theoretical investigation is herein undertaken in order to examine the response of circular cylindrical shells subjected to dynamic loads of an intensity sufficient to cause large permanent deformations. The shell material is assumed to be rigid, perfectly plastic and the influence of finite deflections is retained in the governing equations. It emerges clearly from the study that geometry changes influence markedly the shell behavior even for quite small deflections and, therefore, they should be retained in any dynamic analyses of cylindrical shells with axial restraints.
Large Plastic Deformation of a Circular Sheet Caused by Punch Stretching
Authors: Wang N. M.
Published: April 2010

The stress and strain distributions in a circular sheet caused by the stretching of the sheet with a hemispherical punch are analyzed in terms of an incremental theory of plasticity. The material of the sheet is assumed to have strain-hardening capacity and to be transversely isotropic with respect to the thickness direction. It is found that, at a certain stage in the stretching, a region of the sheet becomes rigid and, at the edge of this rigid region, a surface depression, or neck, having a V-shaped thickness profile is formed. These results are interpreted as a fracture mechanism for the sheet. Numerical results are calculated for the size of the rigid region, the thickness strain at the root of the neck, and the corresponding dome height. The dependence of these quantities on the interfacial friction between the punch and sheet and on the material properties of the sheet is also calculated and shown graphically.
Determination of the Duration of Memory for Viscoelastic Materials
Authors: Gradowczyk M. H. , Soussou J. , Moavenzadeh F.
Published: April 2010

The possibility of limiting the memory of nonlinear nonaging viscoelastic materials is discussed. If the deformation histories are bounded, then the memory interval −∞ < τ ≤ t can be reduced to the finite interval t −d ≤ τ, where d ≥ 0 is the duration of memory. It is shown how the duration in relaxation and creep can be obtained for one-dimensional motions. As an application the duration of memory in relaxation and creep of solid polyurethane is computed from available experimental data. It is also shown that when the functionals are evaluated numerically, the use of the duration reduces significantly the computing time. The case of anisotropic material in three-dimensional motions is also discussed.
Flow Development in a Channel Having a Longitudinally Moving Wall
Authors: Yu H. S. , Sparrow E. M.
Published: April 2010

The problem of laminar flow development in a parallel-plate channel having one moving wall is investigated both analytically and experimentally. In the first phase, an analytical solution for the velocity field is derived by employing a linearized model of the momentum equation. Numerical results are obtained which cover the entire range of operating conditions corresponding to fully forward-moving (i.e., nonreverse) flows. Results for the axial pressure distribution and for the drag force on the moving wall are also presented. The experiments were performed in a channel, one of whose walls was the surface of a rotating cylinder. Air was the working fluid. The operating conditions of the experiment covered the range from uw/u¯ = 0 to 1.5 (uw = velocity of the moving wall, u¯ = mean fluid velocity). Measurements were made of the pressure distribution along the length of the channel. The agreement between the experimental and analytical results was found to be very good, thereby lending support to the analytical model.
Plane Deformation of the Loaded Straight Edge of a Semi-Infinite Linearly Elastic Body Suspended on a Winkler Layer
Authors: Kanninen M. F.
Published: April 2010

A solution for an edge loaded, semi-infinite elastic solid on an elastic foundation is presented. This solution, arising in the development of a nonlinear atomic model for cleavage crack propagation, was obtained by the Fourier method. Example results are given for a uniform load on a finite interval and for a concentrated force, Fig. 1, in terms of the sine and cosine integral functions and their auxiliary forms.