bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative analysis of platinum diffusion parameters in GaAs and GaN semiconductors
Authors: Hsieh Li-Zen , Yeh Der-Hwa
Published: July 2007

The phenomena of platinum (Pt) atoms diffused thermally into n-type GaAs and GaN compound semiconductors have been unveiled. Although the diffusion of Pt into silicon as a carrier lifetime reducer and leakage current minimizer has already been detailed, Pt diffusion into III-V semiconductor has remained unknown. In this study, Pt was surface coated and thermally diffused into (driven-in) GaAs and GaN samples under the temperature range of 500–900°C. The corresponding diffusion constants and diffusion energies were then determined. Different luminescence spectra were observed and analyzed. Among diffused samples, Pt was found to be a shallow donor in GaN semiconductor, but alternatively found as a deep acceptor for Pt-diffused GaAs samples.
Orbital alignment at poly[2-methoxy-5-(2′-ethylhexyloxy)-p-phenylene vinylene interfaces
Authors: Yi Y. , Lyon J. E. , Beerbom M. M. , Schlaf R.
Published: July 2007

The orbital alignment at poly[2-methoxy-5-(2′-ethylhexyloxy)-p-phenylene vinylene (MEH-PPV) interfaces to Au and highly oriented pyrolytic graphite (HOPG) was investigated using x-ray and ultraviolet photoemission spectroscopies in combination with in situ multistep electrospray based thin film deposition. The electrospray deposition method enables deposition of polymers in vacuum directly from solution. This allows the investigation of polymer interfaces without the use of spin coating. Hence interfaces without the presence of significant contamination can be prepared, similar to what is possible at small molecular interfaces using in-vacuum evaporation. The presented experiments suggest, in conjunction with earlier experiments on MEH-PPV/Ag and MEH-PPV/indium tin oxide interfaces, that the currently assumed vacuum level alignment at conjugated polymer interfaces may not hold in all cases.
First principles calculations of mechanical properties of the YVO4 single crystal
Authors: Zhang Jian , Wang Jiyang , Zhang Huaijin , Wang Chunlei , Cong Hengjiang , Deng Longjiang
Published: July 2007

First principles calculations of mechanical properties of the YVO4 single crystal have been carried out after geometry optimization. We demonstrate that using first principles calculations is a simple and fast method for determining mechanical properties from crystals. The calculated elastic stiffness constants Cij are in good agreement with previous experimental data recorded in the literature. Our results also indicate that the anisotropic property of elastic stiffness constants is due to its lattice structure and electron-charge density distribution. The material constant Ms is also discussed in this work.
Fabrication and efficiency evaluation of a hybrid NiCrAl pressure cell up to 4GPa
Authors: Fujiwara Naoki , Matsumoto Takehiko , Nakazawab Kazuko- , Hisada Akihiko , Uwatoko Yoshiya
Published: July 2007

A hybrid NiCrAl pressure cell was fabricated to measure magnetic quantities under high pressure above 3GPa. A pressure of 4.0GPa was achieved and the pressure cell was found to be reusable even after a pressurizing trial up to 4.0GPa. Pressure was monitored using Cu63 nuclear quadrupole resonance of Cu2O and ruby fluorescence. The pressure efficiency of a fresh cell was maintained at 96%, and no appreciable deformation was observed at pressures below 3GPa; on the other hand, the efficiency after pressurizing trials decreased gradually and reached 75% at 4GPa accompanied by a maximum expansion inside the cylinder of 2%.
Properties of microstrip filter with elliptic-fractal pattern
Authors: Wang Sheng , Guo MingSen , Liu Wei , Liu Zheng You , Zhao Xing-Zhong
Published: July 2007

We described the properties of microstrip band gap filter with elliptic-fractal pattern from 40Hzto20GHz. It used the characteristic of the fractal and elliptic pattern to improve the performance of microstrip band gap filter. The center frequencies of gaps of the filter were about 5.5 and 15GHz, and the band stop bandwidth of the filter can be increased by increasing the numbers of the cell of elliptic-fractal pattern. To verify the characteristic of dual-mode band gap filter, we simulated the above microstrip filter with the finite differential time-domain method. The simulation results were in good agreement with the experimental results.
AsS: Bulk inorganic molecular-based chalcogenide glass
Authors: Brazhkin V. V. , Gavrilyuk A. G. , Lyapin A. G. , Timofeev Yu. A. , Katayama Y. , Kohara S.
Published: July 2007

The authors have developed a high pressure method to produce bulk chalcogenide glasses of a unique AsS composition. The structure, optical properties, and stability of the obtained glasses have been studied. Glasses have an intrinsic deep-red color, optical pseudogap Eg≈1.75eV, a broad Urbach absorption tail WU≈120meV, and high temperature stability up to 130°C. AsS glasses show photoinduced transformations, including photocrystallization. The glass structure is largely based on the quasimolecular As4S4 units with partial polymerization providing an example of an inorganic molecular-based glass.
Diagnosis of a Trypanosoma lewisi-like (Herpetosoma) infection in a sick infant from Thailand
Authors: Sarataphan Nachai , Vongpakorn Montakan , Nuansrichay Bandit , Autarkool Nonglux , Keowkarnkah Tiemjan , Rodtian Pranee , Stich Roger W. , Jittapalapong Sathaporn
Published: July 2007

Trypanosomes were observed in a peripheral blood smear from a 45-day-old Thai infant displaying fever, anaemia, cough and anorexia. Human trypanosomiasis is not endemic to Thailand, so parasite identification was undertaken to determine likely sources of the infection. Several morphological parameters of the trypanosomes were similar to those of Trypanosoma evansi and statistically different from those of Trypanosoma lewisi-like parasites from a naturally infected indigenous rat. However, duplicate PCR assays with primers flanking trypanosome rRNA internal transcribed spacer 1 (ITS1) resulted in amplicons of ~623 bp that corresponded to the expected size for T. lewisi-like parasites. The ITS1 sequence from the infant's blood was 98 and 49 % identical to T. lewisi and T. evansi sequences, respectively. Based on molecular results, it was concluded that the infant was infected with a T. lewisi-like (Herpetosoma) species.
One year prospective survey of Candida bloodstream infections in Scotland
Authors: Odds Frank C. , Hanson Mary F. , Davidson Amanda D. , Jacobsen Mette D. , Wright Pauline , Whyte Julie A. , Gow Neil A. R. , Jones Brian L.
Published: July 2007

A 12 month survey of candidaemia in Scotland, UK, in which every Scottish hospital laboratory submitted all blood isolates of yeasts for identification, strain typing and susceptibility testing, provided 300 isolates from 242 patients, generating incidence data of 4.8 cases per 100 000 population per year and 5.9 cases per 100 000 acute occupied bed days; 27.9 % of cases occurred in intensive care units. More than half the patients with candidaemia had an underlying disease involving the abdomen, 78 % had an indwelling intravenous catheter, 62 % had suffered a bacterial infection within the 2 weeks prior to candidaemia and 37 % had undergone a laparotomy.Candida albicanswas the infecting species in 50 % of cases, followed byCandida glabrata(21 %) andCandida parapsilosis(12 %). Seven cases of candidaemia were caused byCandida dubliniensis, which was more prevalent even thanCandida lusitaniaeandCandida tropicalis(six cases each). AmongC. glabrataisolates, 55 % showed reduced susceptibility to fluconazole, but azole resistance among other species was extremely low. Multilocus sequence typing showed isolates with high similarity came from different hospitals across the country, and many different types came from the hospitals that submitted the most isolates, indicating no tendency towards hospital-specific endemic strains. Multiple isolates ofC. albicansandC. glabratafrom individual patients were of the same strain type with single exceptions for each species. The high prevalence of candidaemia in Scotland, relative to other population-based European studies, and the high level of reduced fluconazole susceptibility of ScottishC. glabrataisolates warrant continued future surveillance of invasiveCandidainfections.
Kiwifruit allergy: actinidin is not a major allergen in the United Kingdom
Authors: Lucas J. S. A. , Nieuwenhuizen N. J. , Atkinson R. G. , MacRae E. A. , Cochrane S. A. , Warner J. O. , Hourihane J. O'B.
Published: July 2007

Background
Actinidin has previously been reported as the major allergen in kiwifruit.

Objectives
To investigate the relevance of actinidin in a well‐characterized population of UK patients with kiwifruit allergy.

Methods
To identify the allergens in kiwifruit, using Western blots, we examined the IgE‐binding patterns of 76 patients with a history of kiwifruit allergy, 23 of who had had a positive double‐blind, placebo‐controlled food challenge. In addition, IgE binding to purified native actinidin was studied in 30 patients, and to acidic and basic isoforms of recombinant actinidin in five patients. Inhibition of IgE binding to kiwifruit protein extract by purified native actinidin was investigated by both inhibition immunoblots and inhibition ELISAs using pooled sera.

Results
Twelve protein bands in kiwifruit protein extract were bound by IgE. A protein band with a molecular weight of 38 kDa was the major allergen recognized by 59% of the population. IgE did not bind to actinidin in the kiwifruit protein extract, or to purified native or recombinant forms of actinidin during Western blotting. Pooled sera bound to kiwifruit protein extract but not purified actinidin on ELISA, and pre‐incubating sera with actinidin did not inhibit IgE binding to kiwifruit protein extract on immunoblot or ELISA.

Conclusion
A novel 38 kDa protein, not actinidin, is the major allergen in this large study population. Identification of major allergens in one patient group is therefore not necessarily reproducible in another; therefore, major allergens should not be defined until there is a sufficient body of data from diverse geographical and cultural populations.
A protocol for generating high numbers of mature and functional human mast cells from peripheral blood
Authors: Lappalainen J. , Lindstedt K. A. , Kovanen P. T.
Published: July 2007

Background
Mast cells (MCs) are multi‐functional effector cells with an essential role in innate immunity and host defence, and under several pathological conditions, such as allergy. Here, we aimed at defining the culture conditions that would allow efficient generation of mature and functional human MCs from their progenitor cells.

Methods
Human peripheral blood‐derived CD34+ progenitor cells were cultured in vitro under serum‐free conditions with human stem cell factor for 9 weeks. Growth and differentiation of the cells into MCs were optimized by selected cytokines and a combination of hypoxic and normoxic conditions. MCs were phenotypically characterized by immunocytochemistry, their preformed mediators were quantified, and their functional ability to degranulate and release histamine was tested.

Results
On average, 20 × 106 mature MCs were generated from 0.5 × 106 progenitor cells during 9 weeks of culture, i.e. at least a 40‐fold increase in cell number was achieved. The mature MCs had oval‐shaped non‐lobular nuclei, contained histamine, heparin, tryptase, chymase, and cathepsin G in their secretory granules, and strongly expressed c‐kit (CD117) and Fc epsilon receptor I on their surface. Histamine release from the cells could be brought about by IgE–anti‐IgE cross‐linkage, compound 48/80, substance P, and anaphylatoxin C3a. The MCs remained functional for several weeks after their maturation.

Conclusion
This study describes an efficient protocol for generating mature MCs from human peripheral blood with a functional phenotype of connective tissue‐type MCs. Use of these cultured human MCs will increase our knowledge and understanding about human MC development and biology in human disease.
Interferon‐β reduces the mouse liver fibrosis induced by repeated administration of concanavalin A via the direct and indirect effects
Authors: Tanabe Junichi , Izawa Akiko , Takemi Natsumi , Miyauchi Yasushi , Torii Yuichi , Tsuchiyama Hiromi , Suzuki Tomohiko , Sone Saburo , Ando Kazuki
Published: July 2007

Type I interferons (IFNs), IFN‐α and IFN‐β, are widely used for treating chronic hepatitis C. Although retrospective studies have suggested that type I IFNs have direct antifibrotic effects, little is known about these mechanisms. The present study was designed to clarify the preventive mechanisms of type I IFNs in the progression of fibrosis for the establishment of a more effective therapy. A murine fibrosis model comprising immunological reactions was induced by the administration of concanavalin A (0·3 mg/body) into mice once a week for 4 weeks. Liver injury and the degree of fibrosis were determined by measuring the serum alanine aminotransferase activities and liver hydroxyproline contents with or without IFN‐β pretreatment. IFN‐β suppressed the hepatocellular injury and increased the hydroxyproline content induced by repeated concanavalin A injections, but had no effect on established fibrosis. Furthermore, IFN‐β reduced the expressions of transforming growth factor‐β, basic fibroblast growth factor, collagen type I A2 and tissue inhibitor of metalloproteinase 1 messenger RNAs, which are related to the progression of liver fibrosis. The IFN‐β reduced the liver injury and fibrosis induced by immunological reactions. These data suggest that type I IFNs suppress the progression of cirrhosis through inhibition of repeated hepatocellular injury and/or factors that promote the liver fibrosis induced by hepatitis virus infection.
Evaluation of spontaneous space closure and development of permanent dentition after extraction of hypomineralized permanent first molars
Authors: JÄLEVIK BIRGITTA , MÖLLER MARIE
Published: July 2007

Aim.   The aim of this study was to evaluate spontaneous space closure, development of the permanent dentition, and need for orthodontic treatment after extraction of permanent first molars due to severe molar–incisor hypomineralization (MIH).

Subjects.   Twenty‐seven children aged 5.6–12.7 (median 8.2) years had one to four permanent first molars extracted due to severe MIH. Each case was followed up on individual indications 3.8–8.3 (median 5.7) years after extractions.

The eruption of the permanent dentition, and space closure were documented by orthopantomograms, casts, photographs, and/or bitewings.

Results.  Fifteen children were judged to have a favourable spontaneous development of their permanent dentition without any orthodontic intervention. Seven children were or should be subjected to orthodontic treatment for other reasons registered prior to the extraction. Five children were judged to have a treatment at least caused by the extractions, but three of them abstained because of no subjective treatment need.

Conclusion. Extraction of permanent first molars severely affected by MIH is a good treatment alternative. Favourable spontaneous space reduction and development of the permanent dentition positioning can be expected without any intervention in the majority of cases extracted prior to the eruption of the second molar.
Prognostic significance of mast cell number and microvascular density for the survival of patients with primary colorectal cancer
Authors: Gulubova Maya , Vlaykova Tatyana
Published: July 2007

Background and Aim:  The prognostic relevance of tumor‐related angiogenesis and mast cell presence in colorectal cancer remains controversial. The aim of the current study was to assess the mast cell and microvessel densities (MCD and MVD) in the invasive front of colorectal cancers and to determine their prognostic relevance for survival of the patient with colorectal carcinoma.

Methods:  Histochemistry and immunohistochemistry were used to identify mast cells by toluidine blue (TB) histochemical staining and tryptase (Try) immunohistochemical staining and to determine the MVD in 106 biopsies from patients with 57 colonic and 49 rectal primary cancers. The MVD was assessed using CD31 as an endothelial cell marker.

Results:  Significant positive correlations were found between the MVD in the ‘hot spots’ and MCD‐Try and MCD‐TB (R = 0.623 and R = 0.414, respectively, P < 0.001). The survival analyses showed that the patients with hypovascular tumor tissues had significantly longer survival than those with hypervascular tumor biopsies (P < 0.0001). Analogous significant correlation was observed for MCD‐Try: patients with low MCD‐Try had significantly better prognosis compared to those with high MCD (P = 0.038). In the multivariate Cox's hazard analysis of the ‘hot spots’ MVD was found to be an independent prognostic factor (P = 0.0007), together with the presence of invasion of lymph vessels (P = 0.017) and the presence of regional lymph node metastases (P = 0.028).

Conclusion:  We suggest that the assessment of MVD and tryptase‐positive mast cells in the invasive front of the primary colorectal cancer could be a useful tool for prognosis of patients after surgical therapy.
Health‐related quality of life in Chinese patients with primary biliary cirrhosis
Authors: Wong Grace L‐H , Law Florence M‐Y , Wong Vincent W‐S , Hui Alex Y , Chan Francis K‐L , Sung Joseph J‐Y , Chan Henry L‐Y
Published: July 2007

Background and Aim:  Symptoms and complications of primary biliary cirrhosis (PBC) have been shown to impair patients' health‐related quality of life (HRQOL) in the West. We aimed to measure the HRQOL and to determine the factors associated with worse HRQOL among the Chinese PBC patients in Hong Kong.

Methods:  Chinese patients with biopsy‐proven PBC were compared with an age‐ and gender‐matched control group of patients suffering from uncomplicated hypertension (HT) and chronic hepatitis B (CHB). Their HRQOL was assessed by a Chinese (Hong Kong) version of the 36‐item short‐form health survey (SF‐36). The psychological aspect of patients was assessed by the Hospital Anxiety and Depression Scale (HADS).

Results:  Forty‐four PBC patients aged 60 ± 11 years were identified. PBC patients had more profound impairment in their HRQOL, as evidenced by their significantly lower Physical Component Summary (PCS) scores (39 ± 11 vs 45 ± 9 and 45 ± 11, P = 0.009 and 0.01) and slightly lower Mental Component Summary (MCS) score (47 ± 12 vs 51 ± 10 and 48 ± 11, P = 0.051 and 0.80) as compared with the HT and CHB control groups, respectively. High HADS‐depression score was independently associated with lower PCS scores. More severe fatigue and higher HADS‐anxiety and HADS‐depression scores were independently associated with lower MCS scores.

Conclusion:  Chinese PBC patients have significant impairment of the HRQOL. The anxiety and depression status of patients had important contribution to the HRQOL.
Management of urethral hemangiomas associated with Klippel–Trenaunay–Weber syndrome by endoscopic sclerotherapy
Authors: Terada Naoki , Arakaki Ryuichiro , Okada Yoshiyuki , Kaneko Yoshiyuki , Nishimura Kazuo
Published: July 2007

Abstract:  Klippel–Trenaunay–Weber syndrome (KTS) is an unusual congenital anomaly characterized by cutaneous hemangiomas, varicosities and bony hypertrophy of the extremities. Herein the case is reported of a 24‐year‐old man with urethral bleeding from hemangiomas associated with KTS that were successfully managed by endoscopic sclerotherapy. A 23‐G puncture needle was inserted into the bleeding vein to inject a 5% solution of monoethanolamine oleate (Oldamine), which is typically used for sclerotherapy of esophageal vasix. At a 4‐month follow‐up, the patient only had slightly bloodstained urethral discharge, and is doing well. This is the first case reporting endoscopic sclerotherapy for a KTS‐associated urethral hemangioma.
Elevated plasma factor VIII coagulant activity presenting with thrombophlebitis of the deep dorsal vein of the penis
Authors: Shen Heng‐Li , Liu Shih‐Ping , Wang Sho‐Mon , Tsay Woei , Hsieh Ju‐Ton
Published: July 2007

Abstract:  A 55‐year‐old man started to suffer from severe penile pain 2 days after engaging in sexual intercourse in the woman‐on‐top position. A fixed, 2‐cm long, cord‐like lesion was found on the dorsal midline of his penis which was in a partially tumescent state. Ultrasonography showed part of the deep dorsal vein was obstructed by a hyperechoic mass. Laboratory tests revealed elevated plasma factor VIII coagulant activity. The patient received thrombophlebectomy of the deep dorsal penile vein. Pathology reported venous thrombosis with eosinophilic and lymphocytic infiltration of the venous wall. At the outpatient follow up, painful thrombophlebitic veins at the previous i.v. accesses were noted on his left arm. He has received long‐term warfarin control as suggested by hematologists. This patient represents the first reported case of deep dorsal penile thrombophlebitis associated with elevated plasma factor VIII coagulant activity, which is an independent risk factor of recurrent venous thromboembolism and superficial thrombophlebitis.
Heterochronic shifts during early cranial neural crest cell migration in two ranid frogs
Authors: Mitgutsch Christian , Piekarski Nadine , Olsson Lennart , Haas Alexander
Published: July 2007

We describe the development of the cranial neural crest cell streams relative to embryonic events such as neural tube formation and somite appearance in two Eurasian frog species belonging to the Ranidae, Rana temporaria and Sylvirana nigrovittata, and demonstrate developmental heterochronies. The mandibular stream appeared well developed in R. temporaria at a time when the embryo was still spherical, the neural folds were elevated, and the neural plate was wide open, thus earlier than known from any frog species so far. The appearance of the second stream and its division into hyoid and branchial portions was clearly accelerated in R. temporaria relative to other embryonic events when compared to S. nigrovittata. For example, in R. temporaria, the hyoid and branchial portions of the cranial neural crest cell streams were separated before the neural folds had started to fuse, whereas in S. nigrovittata this event took place only after the neural folds had fused completely. Such ostentatious heterochronies related to the characters used herein have formerly only been reported from comparisons between species belonging to different higher taxa. Our results re‐confirm that to understand the full dynamics of the evolution of development, studies need to implement comparative embryological approaches, and include phylogenetically relatively closely related taxa.
Evaluating the evidence for pancultural self‐enhancement
Authors: Sedikides Constantine , Gaertner Lowell , Vevea Jack L.
Published: July 2007

We do not regard the better‐than‐average effect as ‘the only acceptable measure of self‐enhancement’ (Heine, Kitayama, & Hamamura, 2007b). Rather, we object to meta‐analytical inclusion of effects that are incapable of testing the tactical self‐enhancement hypothesis. In Investigation 1 of Sedikides, Gaertner, and Vevea (2007a), 12 of the 24 effects involved attributes that were unvalidated for domain (collectivistic vs individualistic): these effects are uninformative. The 12 domain‐validated effects supported the hypothesis. In Investigation 2 of Sedikides et al. (2007a), 12 of the 29 effects were deemed irrelevant. None of these effects involved a correlation between: (a) a participant's rating of self and his/her rating of another person; and (b) idiographic importance rating of the comparison attributes. These effects, then, cannot test whether the self–other comparison varies with the personal importance of the comparison attributes. The 17 relevant effects supported the hypothesis. The weight of the evidence points to the panculturality of self‐enhancement.
A COMPREHENSIVE APPROACH FOR SHARING SEMANTIC WEB TRUST RATINGS
Authors: Zhang Jie , Cohen Robin
Published: July 2007

In the context of the Semantic Web, it may be beneficial for a user (consumer) to receive ratings from other users (advisors) regarding the reliability of an information source (provider). We offer a method for building more effective social networks of trust by critiquing the ratings provided by the advisors. Our approach models the consumer's private reputations of advisors based on ratings for providers whom the consumer has had experience with. It models public reputations of the advisors according to all ratings from these advisors for providers, including those who are unknown to the consumer. We then combine private and public reputations by assigning weights for each of them. Experimental results demonstrate that our approach is robust even when there are large numbers of advisors providing large numbers of unfair ratings. We show that we can effectively model the trustworthiness of advisors even when the population of providers grows increasingly large and discuss how our approach is beneficial in modeling providers. As such, we present a framework for sharing ratings of possibly unreliable sources, of value as users on the Semantic Web attempt to critique the trustworthiness of the information they seek.
Exercise hyperaemia: is anything obligatory but the hyperaemia?
Authors: Joyner Michael J. , Wilkins Brad W.
Published: July 2007

Exercise can increase skeletal muscle blood flow by 100‐fold over values observed at rest. As this value was 3 to 4 times higher than so‐called ‘textbook’ values at the time it raised a number of issues about cardiovascular control. However, there is a continuing inability to identify the factor or combination of factors that explain this substantial increase in muscle blood flow. Moreover, these governing mechanism(s) must also explain the precise matching of muscle blood flow to metabolic demand and oxygen use or need. The difficulties identifying the mechanisms for exercise hyperaemia are especially disappointing due to the essentially concurrent discovery in the 1980s that the vascular endothelium was a key site of vasomotor control and that nitric oxide (NO) potentially released from nerves, endothelial cells, directly from tissues such as skeletal muscle, or perhaps released from red blood cells, might participate in vascular control in a way that would permit blood flow and metabolism to be closely matched.
Mild central chemoreflex activation does not alter arterial baroreflex function in healthy humans
Authors: Simmons Grant H. , Manson Julie M. , Halliwill John R.
Published: July 2007

We have previously shown that activation of peripheral chemoreceptors with isocapnic hypoxia resets arterial baroreflex control of heart rate and sympathetic vasoconstrictor outflow to higher pressures, without changes in baroreflex gain. We tested the hypothesis that activation of central chemoreceptors with mild hyperoxic hypercapnia also causes resetting of the arterial baroreflex, but that this resetting would not occur with matched volume and frequency hyperpnoea. Baroreflex control of heart rate (n= 16) and muscle sympathetic nerve activity (microneurography; n= 11) was assessed in healthy men and women, age 20–33 years, using the modified Oxford technique during hyperoxic eucapnia, hyperoxic hyperpnoea and hyperoxic hypercapnia (end‐tidal PCO2+ 5 mmHg above eucapnia). Baroreflex trials were separated by 30 min of rest. While neither hyperpnoea nor hypercapnia changed mean arterial pressure (92.0 ± 1.8 during eucapnia versus 91.0 ± 1.2 and 90.7 ± 1.4 mmHg during hyperpnoea and hypercapnia; P= 0.427) or muscle sympathetic nerve activity (2301 ± 687 during eucapnia versus 2959 ± 987 and 2272 ± 414 total integrated units min−1 during hyperpnoea and hypercapnia; P= 0.653), heart rate was increased from 59.3 ± 2.7 during eucapnia to 63.2 ± 3.0 and 62.4 ± 2.8 beats min−1 during hyperpnoea and hypercapnia (both P < 0.017). Baroreflex gain was not altered by hyperpnoea or hypercapnia. Thus, acute activation of central chemoreceptors with mild hyperoxic hypercapnia does not affect arterial pressure, sympathetic vasoconstrictor outflow, or baroreflex gain. Heart rate is elevated during hyperoxic hypercapnia, but this response is not different from the increase in heart rate produced by matched volume and frequency hyperpnoea. Therefore, mild activation of central chemoreceptors does not appear to alter arterial baroreflex function.
Magnetofluidconvection in a Rotating Porous Layer Under Modulated Temperature on the Boundaries
Authors: Bhadauria B. S.
Published: July 2007

Thermal instability in an electrically conducting fluid saturated porous medium, confined between two horizontal walls, has been investigated in the presence of an applied vertical magnetic field and rotation, using the Brinkman model. The temperature gradient between the walls of the fluid layer consists of a steady part and a time-dependent oscillatory part. Only infinitesimal disturbances are considered. The combined effect of permeability, rotation, vertical magnetic field, and temperature modulation has been investigated using Galerkin’s method and Floquet theory. The value of the critical Rayleigh number is calculated as function of amplitude and frequency of modulation, Chandrasekhar number, Taylor number, porous parameter, Prandtl number, and magnetic Prandtl number. It is found that rotation, magnetic field, and porous medium all have a stabilizing influence on the onset of thermal instability. Further, it is also found that it is possible to advance or delay the onset of convection by proper tuning of the frequency of modulation of the walls’ temperature. In addition the results corresponding to the Brinkman model and Darcy model have been compared for neutral instability.
Simulation Algorithm for Multistream Plate Fin Heat Exchangers Including Axial Conduction, Heat Leakage, and Variable Fluid Property
Authors: Ghosh I. , Sarangi S. K. , Das P. K.
Published: July 2007

The effect of axial conduction through heat exchanger matrix, heat exchange with the surroundings, and variable fluid properties are included in the simulation algorithm of multistream plate fin heat exchangers. The procedure involves partitioning of the exchanger in both axial and normal directions, writing conservation equations for each segment, and solving them using an iterative procedure. In the normal direction, the exchanger is divided into a stack of overlapping two-stream exchangers interacting through their common streams. In the axial direction, the exchanger is successively partitioned to 2k segments, the final value of k being determined by the point where further partitioning has only marginal effect. The effects of axial conduction, heat leakage, and variable fluid properties are illustrated with the help of multistream heat exchanger examples solved by the above-mentioned technique.
The Compatibility of Thin Films and Nanostructures in Thermoelectric Cooling Systems
Authors: Miner Andrew
Published: July 2007

The compatibility of low-dimensional thermoelectric materials in forms such as thin films and nanowires for use in thermoelectric coolers is examined. First-order thermoelectric theory predicts that the cold and hot junction temperatures of a thermoelectric circuit are governed solely by the nondimensional figure of merit, ZT. Performance predictions based on this traditional theory have been more broadly applied to the performance of thermoelectric cooler systems, thereby implying that these coolers may be miniaturized without loss of performance and that system performance is dictated principally by ZT. A nondimensional thermoelectric system model for a cooler is developed and typical performance metrics for thermoelectric coolers are presented along with predictions from traditional theory. Performance is examined as a function of thermoelectric element length for representative system conditions. This system study shows that cooler performance may drop significantly when miniaturized, particularly if the cooling elements are realized at the scale of many recently proposed thermoelectric thin films and nanostructured materials. The system theory illustrates that performance is governed by three nondimensional parameters: an effective thermoelectric figure of merit, ZeTa, the relative ability for heat to be drawn into the cooler, and the relative ability for heat to be rejected from the cooler to the ambient environment. As cooler performance depends both on material properties (ZeTa) as well as the relative scale of the materials with respect to system thermal conductances, the applicability of some low-dimensional forms of materials such as thermoelectric elements may require reevaluation. The realization of high performance coolers based on thermoelectric effects must rely on developing high quality materials realized at an appropriate, application-dependent scale.
Glaciers Dominate Eustatic Sea-Level Rise in the 21st Century
Authors: Meier Mark F. , Dyurgerov Mark B. , Rick Ursula K. , O'Neel Shad , Pfeffer W. Tad , Anderson Robert S. , Anderson Suzanne P. , Glazovsky Andrey F.
Published: July 2007

Ice loss to the sea currently accounts for virtually all of the sea-level rise that is not attributable to ocean warming, and about 60% of the ice loss is from glaciers and ice caps rather than from the two ice sheets. The contribution of these smaller glaciers has accelerated over the past decade, in part due to marked thinning and retreat of marine-terminating glaciers associated with a dynamic instability that is generally not considered in mass-balance and climate modeling. This acceleration of glacier melt may cause 0.1 to 0.25 meter of additional sea-level rise by 2100.
Current Production and Metal Oxide Reduction by
Shewanella oneidensis
MR-1 Wild Type and Mutants
Authors: Bretschger Orianna , Obraztsova Anna , Sturm Carter A. , Chang In Seop , Gorby Yuri A. , Reed Samantha B. , Culley David E. , Reardon Catherine L. , Barua Soumitra , Romine Margaret F. , Zhou Jizhong , Beliaev Alexander S. , Bouhenni Rachida , Saffarini Daad , Mansfeld Florian , Kim Byung-Hong , Fredrickson James K. , Nealson Kenneth H.
Published: July 2007

Shewanella oneidensis
MR-1 is a gram-negative facultative anaerobe capable of utilizing a broad range of electron acceptors, including several solid substrates.
S. oneidensis
MR-1 can reduce Mn(IV) and Fe(III) oxides and can produce current in microbial fuel cells. The mechanisms that are employed by
S. oneidensis
MR-1 to execute these processes have not yet been fully elucidated. Several different
S. oneidensis
MR-1 deletion mutants were generated and tested for current production and metal oxide reduction. The results showed that a few key cytochromes play a role in all of the processes but that their degrees of participation in each process are very different. Overall, these data suggest a very complex picture of electron transfer to solid and soluble substrates by
S. oneidensis
MR-1.
Storm-water jets and plumes in rivers and estuaries
Authors: McCorquodale J Alex
Published: July 2007

The interaction of storm-water discharges with the flow in rivers and estuaries often involves cross-flowing jets or plumes. This paper reviews the theoretical, experimental, numerical, and field research on this topic. The geometry of the outfall, the jet velocity ratio, and the relative density of the discharging flow have been shown to affect the mixing and dilution of the discharge into the ambient water. Storm-water outfalls are typically circular or rectangular; however, there are numerous open channel outfalls that have trapezoidal or irregular cross sections with large width to depth ratios. The extensive research of pioneers such as N. Rajaratnam on jets and plumes has led to the development of software packages for outfall evaluations. The CORMIX model is an example of one of these packages. The research on which these models are based is discussed, and some guidelines are given for estimating the dilution at outfalls with high width to depth ratios.Key words: storm water, outfalls, jets, plumes, cross flow, modelling.
A strategic safety management framework through balanced scorecard and quality function deployment
Authors: Gunduz Murat , Simsek Burak
Published: July 2007

The aim of this paper is to propose a safety management framework for construction companies. A literature review was carried out to identify significant factors that would improve safety performance. Two management tools—namely, the balanced scorecard and quality function deployment (QFD)—were used to construct the framework. Strategic goals were established for each of the following perspectives of the balanced scorecard: financial and cultural, employee, process, and learning. Afterwards, a questionnaire was prepared using the QFD approach. The goals in the financial and cultural perspective were defined as the safety-related needs of the organization ("customer requirements" in the original QFD approach); and the goals in the remaining perspectives included the actions that the organization could take to meet its needs. Results of the questionnaire were used to set the final strategic goals in the balanced scorecard. Safety performance measures and initiatives were used to accomplish the goals in the balanced scorecard. Key words: safety management, balanced scorecard, quality function deployment.
Behavior of wrinkled steel pipelines subjected to cyclic axial loadings
Authors: Das Sreekanta , Cheng J.J Roger , Murray David W
Published: July 2007

Full-scale laboratory tests were carried out at the University of Alberta to investigate the post-wrinkling ultimate behavior of steel pipelines. The pipe specimens exhibited extreme ductile behavior and did not fail in fracture under monotonically increasing axisymmetric compressive axial loads and displacements. Fractures developed at the wrinkled region, however, when a wrinkled pipe specimen was subjected to cyclic strain reversals due to unloading and loading of primary loads. This paper presents test procedures, complete post-wrinkling behavior, fracture limit strain values, and fracture configurations obtained from full-scale tests on wrinkled pipe specimens under cyclic and monotonic axial loadings. Key words: steel pipeline, laboratory testing, cyclic axial loading, wrinkling, post-wrinkling behavior, accordion failure, strain reversals, fracture.
Two-dimensional finite element river morphology model
Authors: Vasquez Jose A , Millar Robert G , Steffler Peter M
Published: July 2007

We report the development and application of a river morphology model based on the two-dimensional depth-averaged hydrodynamic model River2D. This new movable bed version of River2D was applied to simulate the bed elevation changes in four experiments: bed aggradation due to sediment overload, bed degradation by sediment supply shut-off, knickpoint migration, and bar formation in a variable-width channel. Some conditions in these experiments involved quick changes in the upstream boundary conditions, rapidly varied flow, supercritical flow, hydraulic jumps, and secondary flows. The results of the model agreed well with measured data. Notable features of the model are the use of a flexible unstructured mesh based on triangular finite elements to provide higher spatial resolution in areas of interest and transcritical flow capabilities to simulate supercritical flow and hydraulic jumps over movable beds. Key words: numerical modeling, rivers, scour, sedimentation, two-dimensional, finite elements.
Stabilization of sulphidic mine tailings for prevention of metal release and acid drainage using cementitious materials: a review
Authors: Nehdi Moncef , Tariq Amjad
Published: July 2007

Environmental contamination produced by acid generating mines currently represents the largest environmental liability of the mining industry and necessitates the development of novel techniques for its mitigation. This paper reviews existing literature on stabilization of sulphidic mine tailings and prevention of acid mine drainage (AMD). It is shown that stabilization using ordinary portland cement in combination with pozzolanic and cementitious materials could be a viable option. However, variation of mine waste constituents and their interactions with different binders thwart the formulation of a generalized recipe for stabilization and further necessitate research to explore the optimal waste-binder proportions of the stabilized system components for the particular mine tailings under consideration. The demonstrated effective utilization of industrial by-products (fly ash, slag, cement kiln dust, etc.) in the preparation of modified cementitious materials for stabilization of sulphidic mining waste reinforces further interest in this area, not only to cope with acid mine drainage, but also to utilize abundant discarded industrial by-products for various beneficial considerations. This paper critically examines various mine tailings stabilization techniques in the literature, identifies the fundamental mechanisms controlling their performance and the intrinsic parameters of stabilization systems, along with the tailings-binder interaction mechanisms and performance assessment tools for stabilized tailings. Key words: stabilization, mine tailings, acid mine drainage, metallic and metalloid elements, leaching, portland cement, pozzolanic binders.
Organic solvents improve hydrocarbon desorption and biodegradation in highly contaminated weathered soils
Authors: García-Rivero M , Saucedo-Castañeda G , Gutiérrez-Rojas M
Published: July 2007

Slurry phase laboratory microcosms were used to investigate the effect of selected solvents (hexane, benzene, toluene, n-butanol, acetone, and methanol) on desorption and the resulting microbial biodegradation of hydrocarbons in highly contaminated weathered soils. For nonpolar solvents, solubility and desorption of hydrocarbons increased linearly as polarity increased. In desorption and biodegradation assays, toluene significantly increased hydrocarbon consumption by twice as much, in comparison to the control without solvent. After 30 culture days, the initial hydrocarbon concentration in soil (Soxhlet method), 237.2 g kg–1 of dry soil, diminished 21% when toluene was initially added. Saturated and aromatic fractions became degraded to a greater extent in the presence of toluene, 11% and 50%, respectively. The results in this research indicated that the use of solvents is effective in improving both hydrocarbons desorption and biodegradation in highly polluted weathered soils. Key words: slurry phase, overall hydrocarbon biodegradation, solvents, hydrocarbon fractions, biodegradation.
Confidence Interval for Site Index Using Curves Based on Stem Analyses
Authors: Heger L.
Published: July 2007

A method was described for the derivation of confidence intervals for site index using site-index curves based on stem analyses. The method allows assessment of effects on index estimates due to stand age, index level, sample size of heights used in entering the curves, index age, and sample size underlying the curves. Of these effects, the first three were evaluated for a set of curves based on stem analyses of white spruce (Piceaglauca (Moench) Voss) and on index age of 50 years at breast height (BH). With sample averages of 20 heights, about 95% of index estimates were within ±5 ft (1.52 m) of the true value in spruce 25–100 years old at BH on both average quality and extreme quality sites. To ensure this precision in spruce younger than 15 years at BH, 50 heights were required on the average sites and more than 50 on extreme sites.
Clonal Variation in Total Nonstructural Carbohydrates of Trembling Aspen Roots in Three Utah Areas
Authors: Schier G. A. , Johnston R. S.
Published: July 2007

Root samples collected from trembling aspen (Populustremuloides Michx.) clones after leaf-fall at three Utah locations were analyzed for total nonstructural carbohydrates (TNC). TNC were removed from root tissue by a takadiastase enzyme method rarely used in the study of tree physiology. Differences in TNC percentages among clones within areas appeared to be genetic. Age and site were additional factors causing differences among areas.
Effects of Weevil Feeding on Resin Duct Density and Radial Increment in Lodgepole Pine
Authors: Cerezke H. F.
Published: July 2007

Wood discs cut from 23-year-old lodgepole pine (Pinuscontorta Dougl. var. lalifolia Engelm.) stems were analyzed for vertical and radial resin duct densities adjacent to basal injuries caused by the weevil, Hylobiuswarreni Wood. The injury from single attacks continued for at least 2 years and was characterized by reduced radial growth and an abundance of vertical 'traumatic' resin ducts above the wounds. No increase in radial duct density was detected above the wounds.
Duff Consumption by Fire in Eastern Pine Stands
Authors: Wagner C. E. Van
Published: July 2007

Data are presented on the consumption of duff by fire on six plots in a jack pine (Pinusbanksiana L.) stand and six plots in a red and white pine (P. resinosa Ait and P. strobus L.) stand. The amount consumed was found to correlate well with the moisture content of the duff before fire, and with the Duff Moisture Code, a component of the Canadian Forest Weather Index. A tentative theory to account for the amount of duff consumed is presented in terms of (a) downward heat transfer within the flaming front, and (b) the energy required to heat the duff to ignition temperature.
Gaseous Loss of Ammonia Following Urea Application in a Balsam Fir Forest
Authors: Bernier B. , Brazeau M. , Winget C. H.
Published: July 2007

Nitrogen losses through ammonia volatilization increased with increasing rates of application and were 6.8% of 112 kg urea-N/ha after 10 days. Initial humus moisture content within the limits studied affected volatilization rates in the first days but had little effect on overall losses. A discontinuous ammonia-trapping technique for field use is discussed.
Frost Damage to White Spruce Buds
Authors: Clements J. R. , Fraser J. W. , Yeatman C. W.
Published: July 2007

Unopened buds of white spruce (Piceaglauca (Moench) Voss) were damaged by late spring frost. At time of death of the apical meristem the buds were not ready for flushing. As expected on the basis of ground frosts, there was more damage among shorter trees than among taller trees, and more damage among open-grown trees than among understory trees.
Early Detection of Dead Plant Tissue
Authors: Zaerr Joe B.
Published: July 2007

Two methods for detecting dead plant tissue before visual symptoms appear were evaluated. In one method, the rate of recovery of the bioelectrical potential of tissue to its original level after passage of an electric current was tested as an indicator of dead tissue and found unsatisfactory; in the other method, the change in wave form of a square wave electrical pulse passed through plant tissue was the indicator. With this method, leaf tissue from Doublas-fir (Pseudotsugamenziesii Mirb. (Franco)) that had been killed by freezing, steaming, or treatment with an herbicide could be detected. Dead leaf tissue of other species could also be detected, but the damaged tissue had to be compared with undamaged tissue of the same species.
The Growth Response of a Young Pine Plantation to Weed Removal
Authors: Lambert J. L. , Boyle J. R. , Gardner W. R.
Published: July 2007

In May 1969 the weed vegetation on one plot in a 7-year-old red pine (Pinusresinosa Ait.) plantation was killed with herbicides. The site was a glacial outwash plain in Adams County, Wisconsin. Tree diameter growth was 30% greater on the plot without weeds in the summer of 1969, and 8% greater during the first half of the 1970 growing season. Based on relative height growth of the previous year, weed removal increased height growth by 13% in 1970. Growth differences were attributed to increased available water resulting from weed removal because needle water potentials were lower and stomatal resistances much higher in the presence of weeds during dry conditions in the plantation.