bluuebunny/crossref_metadata_2025_split huggingface dataset:
Energy‐dependent scaling of the Dirac equation
Authors: Karwowski Jacek , Pestka Grzegorz 
Published: April 2009

AbstractUsing an energy‐dependent scaling, the Dirac Hamiltonian eigenvalue problem has been transformed to a Lévy–Leblond‐like equation. Its spectrum is bounded from below and the algebraic representation results in an algebraic eigenvalue problem for the large component of the Dirac wavefunction. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
A retention‐time‐shift‐tolerant background subtraction and noise reduction algorithm (BgS‐NoRA) for extraction of drug metabolites in liquid chromatography/mass spectrometry data from biological matrices
Authors: Zhu Peijuan , Ding Wei , Tong Wei , Ghosal Anima , Alton Kevin , Chowdhury Swapan 
Published: April 2009

AbstractA retention‐time‐shift‐tolerant background subtraction and noise reduction algorithm (BgS‐NoRA) is implemented using the statistical programming language R to remove non‐drug‐related ion signals from accurate mass liquid chromatography/mass spectrometry (LC/MS) data. The background‐subtraction part of the algorithm is similar to a previously published procedure (Zhang H and Yang Y. J. Mass Spectrom. 2008, 43: 1181–1190). The noise reduction algorithm (NoRA) is an add‐on feature to help further clean up the residual matrix ion noises after background subtraction. It functions by removing ion signals that are not consistent across many adjacent scans. The effectiveness of BgS‐NoRA was examined in biological matrices by spiking blank plasma extract, bile and urine with diclofenac and ibuprofen that have been pre‐metabolized by microsomal incubation. Efficient removal of background ions permitted the detection of drug‐related ions in in vivo samples (plasma, bile, urine and feces) obtained from rats orally dosed with 14C‐loratadine with minimal interference. Results from these experiments demonstrate that BgS‐NoRA is more effective in removing analyte‐unrelated ions than background subtraction alone. NoRA is shown to be particularly effective in the early retention region for urine samples and middle retention region for bile samples, where the matrix ion signals still dominate the total ion chromatograms (TICs) after background subtraction. In most cases, the TICs after BgS‐NoRA are in excellent qualitative correlation to the radiochromatograms. BgS‐NoRA will be a very useful tool in metabolite detection and identification work, especially in first‐in‐human (FIH) studies and multiple dose toxicology studies where non‐radio‐labeled drugs are administered. Data from these types of studies are critical to meet the latest FDA guidance on Metabolite in Safety Testing (MIST). Copyright © 2009 John Wiley & Sons, Ltd.
Analysis of underivatized oligosaccharides by liquid chromatography/electrospray ionization tandem mass spectrometry with post‐column addition of formic acid
Authors: Verardo Giancarlo , Duse Irene , Callea Alessandro 
Published: April 2009

AbstractUnderivatized oligosaccharides were analyzed by electrospray ionization (ESI) using a linear ion trap mass spectrometer in the negative ion mode with post‐column addition of an aqueous solution of formic acid. Under these conditions all oligosaccharides showed the presence of the corresponding formate adduct [M + HCOO]− with high intensity and easy subsequent low‐energy collision‐induced dissociation (CID) fragmentation using successive MSn experiments. A careful examination of the mass spectra obtained from these MSn experiments pointed out some significant differences useful to identify and quantify the single components in mixtures of coeluted disaccharides. This new sensitive and rapid method was successfully applied to the quantification of oligosaccharides in some juices minimizing sample handling. Copyright © 2009 John Wiley & Sons, Ltd.
Autonomous robot navigation in outdoor cluttered pedestrian walkways
Authors: Morales Yoichi , Carballo Alexander , Takeuchi Eijiro , Aburadani Atsushi , Tsubouchi Takashi 
Published: April 2009

AbstractThis paper describes an implementation of a mobile robot system for autonomous navigation in outdoor concurred walkways. The task was to navigate through nonmodified pedestrian paths with people and bicycles passing by. The robot has multiple redundant sensors, which include wheel encoders, an inertial measurement unit, a differential global positioning system, and four laser scanner sensors. All the computation was done on a single laptop computer. A previously constructed map containing waypoints and landmarks for position correction is given to the robot. The robot system's perception, road extraction, and motion planning are detailed. The system was used and tested in a 1‐km autonomous robot navigation challenge held in the City of Tsukuba, Japan, named “Tsukuba Challenge 2007.” The proposed approach proved to be robust for outdoor navigation in cluttered and crowded walkways, first on campus paths and then running the challenge course multiple times between trials and the challenge final. The paper reports experimental results and overall performance of the system. Finally the lessons learned are discussed. The main contribution of this work is the report of a system integration approach for autonomous outdoor navigation and its evaluation. © 2009 Wiley Periodicals, Inc.
Microinvertebrate dynamics in riverine slackwater and mid‐channel habitats in relation to physico‐chemical parameters and food availability
Authors: Ning Nathan S. P. , Nielsen Daryl L. , Paul Warren L. , Hillman Terry J. , Suter Phil J. 
Published: April 2009

AbstractMicroinvertebrates play a critical role in riverine food webs, and recent studies have hypothesized that slackwaters, non‐flowing regions associated with the main channel, are important for their reproduction and recruitment. However, little is known regarding the population and community dynamics of microinvertebrate communities in slackwater regions, or how they compare with those in mid‐channel regions. This study examined microinvertebrate communities in the epibenthic and pelagic zones of slackwater and mid‐channel regions (i.e. four habitats) of an Australian floodplain river in relation to physico‐chemical parameters and food availability (as estimated by chlorophyll‐a concentration) between September 2005 and November 2006. Results from this study indicate that microinvertebrate abundance and diversity were greater in slackwater habitats than mid‐channel habitats overall, corresponding with the slower current velocities associated with the former. Nevertheless, communities in all four habitats were most abundant and diverse in late spring (coinciding with an increase in water temperature), and followed similar seasonal trajectories in terms of density, taxon richness and community structure. These findings support the view that slackwaters are important for in‐channel microinvertebrate production, and suggest that animals frequently disperse (either actively or passively) among slackwater and other main channel regions year round. Given the critical importance of microinvertebrates in riverine food webs, rivers should be managed with a view to maintaining a natural variety of accessible slackwater regions in order to support the production and survival of microinvertebrate communities. Copyright © 2009 John Wiley & Sons, Ltd.
Extending DerSimonian and Laird's methodology to perform multivariate random effects meta‐analyses
Authors: Jackson Dan , White Ian R. , Thompson Simon G. 
Published: April 2009

AbstractMultivariate meta‐analysis is increasingly used in medical statistics. In the univariate setting, the non‐iterative method proposed by DerSimonian and Laird is a simple and now standard way of performing random effects meta‐analyses. We propose a natural and easily implemented multivariate extension of this procedure which is accessible to applied researchers and provides a much less computationally intensive alternative to existing methods. In a simulation study, the proposed procedure performs similarly in almost all ways to the more established iterative restricted maximum likelihood approach. The method is applied to some real data sets and an extension to multivariate meta‐regression is described. Copyright © 2009 John Wiley & Sons, Ltd.
Cell Docking in Double Grooves in a Microfluidic Channel
Authors: Khabiry Masoud , Chung Bong Geun , Hancock Matthew J. , Soundararajan Harish Chandra , Du Yanan , Cropek Donald , Lee Won Gu , Khademhosseini Ali 
Published: April 2009

AbstractMicrostructures that generate shear‐protected regions in microchannels can rapidly immobilize cells for cell‐based biosensing and drug screening. Here, a two‐step fabrication method is used to generate double microgrooves with various depth ratios to achieve controlled double‐level cell patterning while still providing shear protection. Six microgroove geometries are fabricated with different groove widths and depth ratios. Two modes of cell docking are observed: cells docked upstream in sufficiently deep and narrow grooves, and downstream in shallow, wide grooves. Computational flow simulations link the groove geometry and bottom shear stress to the experimental cell docking patterns. Analysis of the experimental cell retention in the double grooves demonstrates its linear dependence on inlet flow speed, with slope inversely proportional to the sheltering provided by the groove geometry. Thus, double‐grooved microstructures in microfluidic channels provide shear‐protected regions for cell docking and immobilization and appear promising for cell‐based biosensing and drug discovery.
Finding failures from passed test cases: improving the pattern classification approach to the testing of mesh simplification programs
Authors: Chan W. K. , Ho Jeffrey C. F. , Tse T. H. 
Published: April 2009

AbstractMesh simplification programs create three‐dimensional polygonal models similar to an original polygonal model, and yet use fewer polygons. They produce different graphics even though they are based on the same original polygonal model. This results in a test oracle problem. To address the problem, our previous work has developed a technique that uses a reference model of the program under test to train a classifier. Using such an approach may mistakenly mark a failure‐causing test case as passed. It lowers the testing effectiveness of revealing failures. This paper suggests piping the test cases marked as passed by a statistical pattern classification module to an analytical metamorphic testing (MT) module. We evaluate our approach empirically using three subject programs with over 2700 program mutants. The result shows that, using a resembling reference model to train a classifier, the integrated approach can significantly improve the failure detection effectiveness of the pattern classification approach. We also explain how MT in our design trades specificity for sensitivity. Copyright © 2009 John Wiley & Sons, Ltd.
Sulfur dioxide and benzo(a)pyrene modulates CYP1A and tumor‐related gene expression in rat liver
Authors: Qin Guohua , Meng Ziqiang 
Published: April 2009

AbstractSulfur dioxide (SO2) and benzo(a)pyrene (B(a)P) are common industrial and environmental contaminants. However, few data are available on the effects of SO2on proto‐oncogenes and tumor suppressor genes, as well as the interactions between SO2and other xenobiotics regulating proto‐oncogenes or tumor suppressor genes expression. To investigate the interactions between SO2and B(a)P, male Wistar rats were exposed to intratracheally instilled with B(a)P or SO2inhalation alone or together. We detected mRNA expression ofCYP1A1and1A2, 7‐ethoxyresorufinO‐deethylase (EROD), and methoxyresorufinO‐demethylase (MROD) activities in livers. The mRNA and protein levels of several cancer‐related genes were analyzed in livers by real‐time RT‐PCR and Western blot, respectively. The EROD/MROD activities andCYP1A1/2expression were down‐regulated by SO2but up‐regulated by B(a)P alone. Exposure of SO2alone induced c‐fos, c‐jun, c‐myc, H‐ras, and p53 expression, and depressed p16 and Rb expression in livers. The effects of B(a)P on the above gene were similar to SO2except c‐fos expression. Furthermore, SO2+ B(a)P exposure increased the expression of c‐fos, c‐jun, c‐myc, and p53, and decreased p16 and Rb expression in livers compared with exposed to SO2or B(a)P alone. However, no synergistic effects were observed on H‐ras and CYP1A1/2 after SO2+ B(a)P exposure. Our findings indicate that multiple cell cycle regulatory proteins play key roles in the toxicity of SO2and B(a)P in livers. It might involve the activation of c‐fos, c‐jun, c‐myc, and p53. And p16‐Rb pathway might also participate in the progress. Although the gene products we studied are classed as oncogenes and tumor suppressor genes, their functions actually relate to more general processes of control of cell proliferation, survival, and/or apoptosis. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2010.
Crosslinking of plasticized PVC used in coated fabrics
Authors: Zadhoush A. , Esmaeili M. , Ghaeli I. 
Published: April 2009

AbstractCrosslinking is effective in improving the properties of plasticized poly(vinyl chloride) (PPVC), such as mechanical, chemical, and thermal resistance. In this study, the crosslinking was carried out using di‐tert‐butyl peroxide as an initiator in the presence of 1,1,1‐trimethylolpropane trimethacrylate (TMPTMA) as a crosslinking agent at two different curing temperatures. The degree of crosslinking was measured in terms of gel content and tensile strength. Upon increasing the amount of peroxide to an optimum level, the gel content and tensile strength increased to a maximum point, and above this level, the peroxide caused a slight decrease in crosslinking, which was due to the scission of PPVC chains during thermal degradation. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers
Characterization of 1,5‐pentanediol dibenzoate as a potential “green” plasticizer for poly(vinyl chloride)
Authors: Firlotte Nicolas , Cooper David G. , Marić Milan , Nicell James A. 
Published: April 2009

Abstract1,5‐Pentanediol dibenzoate (PDDB) was evaluated as a potential “green” plasticizer for poly(vinyl chloride) (PVC) at concentrations ranging between 20 and 80 parts by weight per hundred parts of resin. The results of glass transition temperature (Tg) and tensile tests of PDDB blends with PVC were compared with those for blends of the commercial plasticizers di(2‐ethylhexyl) phthalate (DEHP), di(ethylene glycol) dibenzoate (DEGDB), and di(propylene glycol) dibenzoate (DPGDB) in PVC. The depression in Tg and the tensile properties were comparable for a PDDB/PVC blend at a fixed composition to those of blends with DEHP, DEGDB, and DPGDB. The PDDB was subjected to biodegradation using co‐metabolism by the common soil bacterium Rhodococcus rhodochrous (ATCC 13808). After 16 days of growth, nearly all of the PDDB was degraded, and only small amounts of transient, unidentified metabolites were observed in the growth medium during the experiment. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers
Fluorescence correlation spectroscopy and fluorescence cross‐correlation spectroscopy
Authors: Digman Michelle A. , Gratton Enrico 
Published: April 2009

AbstractThis article focuses on methods based on fluctuation correlation spectroscopy to determine the formation of protein complexes in living cells. We present the principles of the fluctuation method applied to cells. We discuss the novelty and the promises of this approach. The emphasis is in the discussion of the underlying statistical assumptions of the image correlation spectroscopy analysis rather than in reviewing applications of the method. Although one example of the application of the fluctuation method is given, this article also contains simulations that are better suited to illustrate and support the basic assumptions of the method. Copyright © 2009 John Wiley & Sons, Inc.This article is categorized under:

Laboratory Methods and Technologies > Proteomics Methods
Leisure activities and adolescent psychological well‐being
Authors: Trainor Sarah , Delfabbro Paul , Anderson Sarah , Winefield Anthony 
Published: April 2009

ABSTRACTWe examined the validity of the reported link between well‐being and leisure participation in adolescents. Nine hundred and forty‐seven, Year 10 students from 19 schools in Adelaide, South Australia, were recruited. Participants completed a questionnaire concerning participation in social, non‐social and unstructured leisure activities as well as measures of personality. As expected, personality variables were better predictors of adolescent well‐being than spare‐time use, although engagement in less structured leisure activities was associated with poorer psychological well‐being and substance use. These findings support previous personality research which suggests that spare‐time use may be related to well‐being only insofar as individuals who are psychologically healthy tend to be involved in structured leisure activities. The implications of these findings for school policy and future research concerning the links between leisure involvement and psychological well‐being are discussed.
Dietary intakes of children with Crohn's disease
Authors: Pons Rachel , Whitten Kylie E. , Woodhead Helen , Leach Steven T. , Lemberg Daniel A. , Day Andrew S. 
Published: April 2009

Approximately 25 % of individuals with Crohn's disease (CD), a life-long relapsing-remitting disease, are diagnosed during childhood and adolescence. Symptoms of CD, including abdominal pain, nausea and diarrhoea, can lead to reduced food intake, which may negatively have an impact on nutritional status during this critical period of growth and development. The aims of the present study were to assess the growth and adequacy of dietary intakes of children with CD at Sydney Children's Hospital, Randwick, and compare with healthy controls. Sixty-three subjects aged 10–16 years were recruited, including: children with active CD (n18), children with CD in remission (n23) and healthy controls (n22). Dietary intake was assessed using a FFQ and compared with current Australian recommended dietary intakes (RDI). Growth and dietary intakes were compared between groups. Subjects with active CD had lower weight and BMIZscores than children in remission and controls. The energy intakes of children with active CD and those in remission were significantly lower than estimated energy requirements (P = 0·001 andP = 0·03 respectively). Children with active CD did not meet the RDI for Fe and their Ca intake was lower than the RDI (P = 0·04). In conclusion, the dietary intake of children with active CD was impaired, with inadequate intakes of energy, Ca and Fe. Reduced energy intakes during active disease may contribute to poor weight gain and impaired growth. Quantifying nutrient intake and ascertaining requirements for nutritional supplementation are essential components of successful management in paediatric CD.
Leptin concentrations and the immune-mediated reduction of feed intake in sheep infected with the nematode Trichostrongylus colubriformis
Authors: Greer Andrew W. , Boisclair Yves R. , Stankiewicz Miroslaw , McAnulty Robin W. , Jay Nigel P. , Sykes Andrew R. 
Published: April 2009

The hypothesis that increases in the concentration of the anorectic peptide leptin may be responsible for the immune-mediated reduction in feed intake (FI) during gastrointestinal parasitism in sheep was investigated. In a 2 × 2 × 2 factorial design, the first factor was age at the start of infection (5 months old v. 17 months old). The second factor was parasite infection (no infection v. administration of eighty L3 infective Trichostrongylus colubriformis larvae/kg live weight (LW) per d three times per week for 77 d). The third factor was immunosuppressive therapy with a corticosteroid (no therapy or weekly intramuscular injection of 40 mg methylprednisolone acetate/30 kg LW). Relative to their uninfected counterparts, a 20 % reduction in FI per unit LW (FI/LW; g DM/kg LW) was observed in infected non-suppressed 5-month-old lambs from 21 to 63 d post-infection (P < 0·001) but not in comparable17-month-old ewes or in corticosteroid-treated lambs or ewes (P>0·05 for all), allowing the suggestion that the anorexia was a consequence of the developing immune response. The reduction in FI/LW in 5-month-old lambs was not associated with an increase in plasma leptin concentration. Furthermore, plasma leptin concentrations were greater in corticosteroid-treated animals (P < 0·001) and in 17-month-old animals (P < 0·001), none of which displayed an infection-induced reduction in FI/LW. Plasma leptin was positively correlated with carcass fat percentage in both 5-month-old (P = 0·016) and 17-month-old (P < 0·001) animals and did not appear to provide a direct feedback mechanism that restricted energy intake. The results do not support the hypothesis that an increase in circulating leptin is directly responsible for the immune-mediated anorexia in lambs during T. colubriformis infection.
Quercetin reduces systolic blood pressure and plasma oxidised low-density lipoprotein concentrations in overweight subjects with a high-cardiovascular disease risk phenotype: a double-blinded, placebo-controlled cross-over study
Authors: Egert Sarah , Bosy-Westphal Anja , Seiberl Jasmin , Kürbitz Claudia , Settler Uta , Plachta-Danielzik Sandra , Wagner Anika E. , Frank Jan , Schrezenmeir Jürgen , Rimbach Gerald , Wolffram Siegfried , Müller Manfred J. 
Published: April 2009

Regular consumption of flavonoids may reduce the risk for CVD. However, the effects of individual flavonoids, for example, quercetin, remain unclear. The present study was undertaken to examine the effects of quercetin supplementation on blood pressure, lipid metabolism, markers of oxidative stress, inflammation, and body composition in an at-risk population of ninety-three overweight or obese subjects aged 25–65 years with metabolic syndrome traits. Subjects were randomised to receive 150 mg quercetin/d in a double-blinded, placebo-controlled cross-over trial with 6-week treatment periods separated by a 5-week washout period. Mean fasting plasma quercetin concentrations increased from 71 to 269 nmol/l (P < 0·001) during quercetin treatment. In contrast to placebo, quercetin decreased systolic blood pressure (SBP) by 2·6 mmHg (P < 0·01) in the entire study group, by 2·9 mmHg (P < 0·01) in the subgroup of hypertensive subjects and by 3·7 mmHg (P < 0·001) in the subgroup of younger adults aged 25–50 years. Quercetin decreased serum HDL-cholesterol concentrations (P < 0·001), while total cholesterol, TAG and the LDL:HDL-cholesterol and TAG:HDL-cholesterol ratios were unaltered. Quercetin significantly decreased plasma concentrations of atherogenic oxidised LDL, but did not affect TNF-α and C-reactive protein when compared with placebo. Quercetin supplementation had no effects on nutritional status. Blood parameters of liver and kidney function, haematology and serum electrolytes did not reveal any adverse effects of quercetin. In conclusion, quercetin reduced SBP and plasma oxidised LDL concentrations in overweight subjects with a high-CVD risk phenotype. Our findings provide further evidence that quercetin may provide protection against CVD.