bluuebunny/crossref_metadata_2025_split huggingface dataset:
Students' ideas on conservation of matter: Effects of expertise and context variables
Authors: Gomez Miguel‐Angel , Pozo Juan‐Ignacio , Sanz Angeles 
Published: October 2006

AbstractRecent research on chemistry learning and teaching has described some alternative conceptions held by students as to their understanding of the properties of matter. Several classifications have been proposed to analyze students' conceptions about matter and its changes. Starting from Anderson's categorization, this research studied students' understanding of the qualitative conservation of matter (substance), and how this understanding is influenced by previous instruction in chemistry and task variables. Here, task variables include chemical content and problem context. Four groups of adolescents that differed in age (from 12 to 17 years) and scientific instruction, and two groups of university students with different expertise in chemistry were presented with a 22‐item paper‐and‐pencil test about the conservation of matter. The items involved physical changes (solutions or changes of state) and chemical changes (reactions), and were posed both in academic chemistry contexts and everyday situations. Results show the influence of group membership, task content, and problem context on students' performance. Test scores increased with age and instruction in chemistry, but the influence of chemical expertise was smaller than that predicted from research in other scientific areas. Concerning context, for everyday situations reactions are the most difficult content; on the other hand, in academic chemistry the most difficult content was solutions. Analyses for category answers showed that subjects are likely to concentrate their interpretations in two main categories, interaction (substances interact to form new ones) and modification with identity (substances modified in appearance continue to be the same). However, conceptions depend also significantly on content and context task. Finally, we have found that science instruction increases the consistency of the conceptions held by subjects. Younger subjects and adolescents without scientific instruction tended to be less consistent than more expert subjects. © 1995 John Wiley & Sons, Inc.
Learning to live with scientific expertise: Toward a theory of intellectual communalism for guiding science teaching
Authors: Norris Stephen P. 
Published: October 2006

AbstractA long–standing goal of science education is teaching students to be intellectually independent of scientific experts. This article proposes that this goal be abandoned as impossible to attain, and be replaced by a goal of intellectual communalism between scientists and nonscientists. The argument draws upon work demonstrating that epistemic dependence of nonexperts upon experts and of experts upon each other is an unavoidable characteristic of knowledge acquisition. This dependence implies both the need for trust in expertise and for expertise to be used responsibly. Faced with epistemic dependence, the alternative of intellectual communalism for science is recunimended in which nonscientists defer to scientists on matters of evidence for scientific knowledge claims, but use the combined judgment of scientists critically to assess alleged scientific expertise. It is claimed that scientists have no special experrise in the use of scientific knowledge, and that nonscientists must play an evaluative role in this regard. The sort of instruction proposed to achieve the goal of intellectual communalism consists of standard instruction in scientific knowledge, metascientific discussion about the nature of scientific knowledge and expertise, and instruction and practice in judging expertise. © 1995 John Wiley & Sons, Inc.
Children's conceptions of light in the context of a technology‐based curriculum
Authors: Settlage John 
Published: October 2006

AbstractThird graders in an urban classroom participated in an 8‐week unit in which they studied the behavior of light. At the core of the curriculum was a light‐sensing probe interfaced with a computer. This case study describes the investigation of this technology, commonly referred to as microcomputer‐based labs (MBLs), for its appropriateness for elementary school students. One finding of this study was that the children expanded their repertoire of graph making and interpreting skills with line graphs becoming a useful means for representing light intensity. The other assertion was that the MBL became a tool that supported scientific inquiry for and by the children. The author cautions that technology itself should not be regarded as the source of knowledge for learners, but that computers have the potential for reshaping how teachers approach science instruction. © 1995 John Wiley & Sons, Inc.I have no doubt at all that increased skill and confidence would come to many people if they engaged in more respectful and thoughtful talk about their learning processes…. None of this absolutely requires computers. What we see … is how the computer simply, but very significantly, enlarges the range of opportunities to engage … in activities with scientific and mathematical content.
Using standards in professional preparation
Authors: Miller Theodore K. 
Published: October 2006

AbstractProfessional standards and guidelines are of special value in the area of academic preparation, for it is in this arena that the seeds of professional practice are initially planted. It is essential that those who aspire to become professional student affairs practitioners and educators receive the best preparation possible. Preparation standards are the essential foundation for quality education, and it is important that professionals know and understand how to apply standards to the educational process.
Editor's notes
Authors: Guskin Alan E. 
Published: October 2006

AbstractAlan E. Guskin, a social psychologist, has been chancellor of the University of Wisconsin‐Parkside for the last six years. Previously, he served as provost and acting president of Clark University in Worcester, Massachusetts. He has served as chairman of the Advisory Committee of the Resource Center for Planned Change and is a member of the Board of Directors of the American Association of State Colleges and Universities.
THOR: targeted high-throughput ortholog reconstructor
Authors: Bainbridge Matthew N. , Warren René L. , He An , Bilenky Mikhail , Robertson A. Gordon , Jones Steven J.M. 
Published: October 2006

AbstractSummary: Low-coverage genomes (LCGs) are becoming an increasingly important source of data for phylogenetic studies. However, assembly of these genomes is time consuming, difficult and lags behind sequence generation. THOR is a fast, stringent application for targeted reconstruction of sequence orthologs in unassembled LCGs. Using a 4× coverage set of mouse whole-genome sequence reads, THOR could partially or completely reconstruct 416/1000 human promoter ortholog regions in ∼7.3 min/promoter. THOR's reconstruction rate improves markedly with both higher-coverage, and less divergent target species.Availability: THOR is implemented in java and is currently available as source code and as a web service (www.bcgsc.ca/services/thor) for reconstructing human sequences.Contact: matthewb@bcgsc.ca
ssSNPer: identifying statistically similar SNPs to aid interpretation of genetic association studies
Authors: Nyholt Dale R. 
Published: October 2006

Abstract
Summary: ssSNPer is a novel user-friendly web interface that provides easy determination of the number and location of untested HapMap SNPs, in the region surrounding a tested HapMap SNP, which are statistically similar and would thus produce comparable and perhaps more significant association results. Identification of ssSNPs can have crucial implications for the interpretation of the initial association results and the design of follow-up studies.
Availability:
Contact: daleN@qimr.edu.au
Right Ventricular Outflow Tract Pacing: Practical and Beneficial. A 9‐Year Experience of 460 Consecutive Implants
Authors: VLAY STEPHEN C. 
Published: October 2006

Background: Pacing from the right ventricular apex (RVA) in patients with ventricular dysfunction has been identified as a possible contributor to deterioration of ventricular function. Therefore, alternative pacing sites such as the right ventricular outflow tract (RVOT) are receiving intensified scrutiny. An unresolved question is whether technical, procedural, and stability issues are comparable for the RVA and the RVOT.
Methods: This report details 460 consecutive ventricular pacing lead implants with the primary intended site in the RVOT. Patients were evaluated for success, complication rates, and followed‐up for stability of pacing parameters. The total patient implant population included 300 male and 170 female patients with a mean age of 70.6 years. Ten patients were excluded from the analysis, since there was a primary indication and intention to implant in the RVA, leaving a total of 460 patients for analysis. The indications for pacing were symptomatic bradycardia due to any cause and/or Mobitz II or complete heart block. There was no clinical evidence of heart failure in 420 patients. In 40 patients with heart failure, the indication for pacing was cardiac resynchronization therapy using the RVOT as an alternate site when pacing from a branch vein of the coronary sinus was not possible. Outcome information was obtained from the implanter's clinic.
Results: The overall success rate in the RVOT was 84% over the total 9‐year period with a 92% success rate in the last 4½ years, using the RVOT technique described. At 20 months in a subgroup comparison of RVOT and RVA implants, there was no significant difference in pacing threshold, R‐wave sensing, or pacing lead impedance. Dislodgment occurred in only 1 of 460 patients. Reasons for failure to implant in the RVOT include inability to find a stable position with adequate pacing and sensing thresholds (related to anatomy, scarred myocardium, pulmonary hypertension, tricuspid regurgitation), hemodynamic instability limiting time for implant, and a learning curve. Long‐term stability and lead performance were excellent, and certain acute and chronic complications of RV pacing did not occur.
Does RV Lead Positioning Provide Additional Benefit to Cardiac Resynchronization Therapy in Patients with Advanced Heart Failure?
Authors: SHIMANO MASAYUKI , INDEN YASUYA , YOSHIDA YUKIHIKO , TSUJI YUKIOMI , TSUBOI NAOYA , OKADA TARO , YAMADA TAKUMI , MURAKAMI YOSHIMASA , TAKADA YASUNOBU , HIRAYAMA HARUO , MUROHARA TOYOAKI 
Published: October 2006

Background and Objectives: The left ventricular (LV) stimulation site is currently recommended to position the lead at the lateral wall. However, little is known as to whether right ventricular (RV) lead positioning is also important for cardiac resynchronization therapy. This study compared the acute hemodynamic response to biventricular pacing (BiV) at two different RV stimulation sites: RV high septum (RVHS) and RV apex (RVA).
Methods and Results: Using micro‐manometer‐tipped catheter, LV pressure was measured during BiV pacing at RV (RVA or RVHS) and LV free wall in 33 patients. Changes in LV dP/dtmax and dP/dtmin from baseline were compared between RVA and RVHS. BiV pacing increased dP/dtmax by 30.3 ± 1.2% in RVHS and by 33.3 ± 1.7% in RVA (P = n.s.), and decreased dP/dtmin by 11.4 ± 0.7% in RVHS and by 13.0 ± 1.0% in RVA (P = n.s.). To explore the optimal combination of RV and LV stimulation sites, we assessed separately the role of RV positioning with LV pacing at anterolateral (AL), lateral (LAT), or posterolateral (PL) segment. When the LV was paced at AL or LAT, the increase in dP/dtmax with RVHS pacing was smaller than that with RVA pacing (AL: 12.2 ± 2.2% vs 19.3 ± 2.1%, P < 0.05; LAT: 22.0 ± 2.7% vs 28.5 ± 2.2%, P < 0.05). There was no difference in dP/dtmin between RVHS‐ and RVA pacing in individual LV segments.
Conclusions: RVHS stimulation has no overall advantage as an alternative stimulation site for RVA during BiV pacing. RVHS was equivalent with RVA in combination with the PL LV site, while RVA was superior to RVHS in combination with AL or LAT LV site.
Spatial Distribution of Repolarization and Depolarization Abnormalities Evaluated by Body Surface Potential Mapping in Patients with Brugada Syndrome
Authors: YOKOKAWA MIKI , TAKAKI HIROSHI , NODA TAKASHI , SATOMI KAZUHIRO , SUYAMA KAZUHIRO , KURITA TAKASHI , KAMAKURA SHIRO , SHIMIZU WATARU 
Published: October 2006

Background: Mutations in sodium channel gene, SCN5A, have been identified in Brugada syndrome, but it is still unclear as to how sodium channel dysfunction relates to arrhythmogenesis. We examined spatial distribution of both repolarization and depolarization abnormalities in patients with Brugada syndrome by using 87‐leads body surface potential mapping (BSPM).
Methods: BSPM was recorded under baseline condition and after pharmacological interventions in 28 patients with Brugada syndrome (27 males, 49 ± 14 years). The ST‐segment amplitude 20 ms after the end of QRS (ST20), QRS duration, and corrected recovery time (RTc) were measured in all 87‐leads, and averaged among 6‐leads (D–F, 5–6) reflecting right ventricular outflow tract (RVOT) potentials and the other 81‐leads.
Results: The ST20 was elevated at baseline, normalized by isoproterenol, and augmented by pilsicainide in only the RVOT. The RTc was longer at baseline and increased by pilsicainide in only the RVOT. On the other hand, the QRS duration was slightly widened at baseline, further increased by pilsicainide, but not changed by isoproterenol in both leads.
Conclusions: The ST‐segment elevation and the RTc prolongation were localized and modulated by agents only in the RVOT region, while the slight QRS widening at baseline and further increase by pilsicainide were observed homogeneously. Our data suggest that depolarization abnormalities are distributed homogeneously, whereas repolarization abnormalities are localized in the RVOT.
ANTIBACTERIAL ACTIVITY OF EXTRACTS FROM FAMILY ZINGIBERACEAE AGAINST FOODBORNE PATHOGENS
Authors: VORAVUTHIKUNCHAI S.P. , LIMSUWAN S. , SUPAPOL O. , SUBHADHIRASAKUL S. 
Published: October 2006

ABSTRACT Chloroformic extracts of selected Thai medicinal plants commonly employed to treat infections were investigated for their antibacterial activity against important foodborne pathogenic bacteria. These included Bacillus cereus, Staphylococcus aureus, methicillin‐resistant S. aureus (MRSA), Escherichia coli O157:H7, Salmonella Typhi and Shigella sp. Among 33 extracts tested, only chloroformic extracts of five plant species exhibited antibacterial properties. Alpinia galanga, Boesenbergia rotunda, Zingiber zerumbet and Piper betel were active against S. aureus. Barleria lupulina was active against B. cereus. Only the extract from P. betel leaves possessed activity against gram‐negative bacteria. As extracts from the three plant species belonging to family Zingiberaceae displayed strong activity against S. aureus, they were further tested against 17 clinical isolates. Minimum inhibitory concentration (MIC) values of B. rotunda, A. galanga and Z. zerumbet extracts against most clinical S. aureus isolates were 0.01, 0.19 and 0.79 mg/mL and the minimum bactericidal concentration (MBC) values were 0.19, 1.57 and >12.5 mg/mL, respectively. Significant growth inhibition of MRSA was observed in the cultures incubated in the presence of the B. rotunda extract, A. galanga and Z. zerumbet. B. rotunda exhibited the greatest activity among the three plant species against S. aureus at MIC, 2MIC and MBC within 2 h.
DUAL‐PHASIC INACTIVATION OF ESCHERICHIA COLI O157:H7 WITH PEROXYACETIC ACID, ACIDIC ELECTROLYZED WATER AND CHLORINE ON CANTALOUPES AND FRESH‐CUT APPLES
Authors: WANG HUA , FENG HAO , LUO YAGUANG 
Published: October 2006

ABSTRACT The effects of peroxyacetic acid (POAA), acidic electrolyzed water (AEW) and chlorine on inactivation of Escherichia coli O157:H7 on fresh‐cut apples and cantaloupe rinds were investigated. Apple cylinders were dip‐inoculated with E. coli O157:H7 and treated with sterilized water (control), chlorine, AEW or POAA for up to 8 min. Cantaloupe cylinders were spot‐inoculated with E. coli O157:H7 to the rind and treated with sterilized water, AEW or POAA for up to 15 min. All sanitizer treatments showed a significantly (P < 0.05) higher inactivation than the control. The residual counts of E. coli O157:H7 on both fruits exhibited a dual‐phasic reduction behavior, with a fast inactivation (D values: 0.8–5.0 min) in the first minute (phase I) of treatments followed by a much slower inactivation (D values: 14.6–59.8 min) in the remaining time (phase II). The dual‐phasic inactivation seems to be related to fruit surface topography that determines the bacterial distribution.
GAUGE SYMMETRY BREAKING IN ORBIFOLD MODEL BUILDING
Authors: TRAPLETTI MICHELE 
Published: October 2006

We review the gauge symmetry breaking mechanism due to orbifold projections in orbifold model building. We explicitly show the existence of a scale of breaking if such a symmetry breaking is due to freely-acting orbifold operators only, i.e. in case the breaking is realized nonlocally in the internal space. We show that such a scale is related to the compactification moduli only, and that there are no extra continuous parameters, at least in semirealistic models with [Formula: see text] SUSY in four dimensions. In this sense, the mechanism is peculiarly different from the standard Higgs (or Hosotani) symmetry breaking mechanism. We show that the mechanism also differs from that present in standard orbifold models where, even in the presence of discrete Wilson lines, a scale of breaking is generically missing, since the breaking is localized in specific points in the internal space. We review a set of background geometries where the described nonlocal breaking is realized, both in the case of two and six extra dimensions. In the latter case, relevant in string model building, we consider both heterotic and open string compactifications.
Small-Scale Horizontal Rain-Rate Variability Observed by Satellite
Authors: Varma Atul K. , Liu Guosheng 
Published: October 2006

Abstract
The horizontal distribution of rain rates within an area comparable to the pixel size of satellite microwave radiometers and the grid size of numerical weather prediction models has been studied over the global Tropics using three years of the Tropical Rainfall Measuring Mission satellite precipitation radar (PR) data. The global distribution of rain-rate standard deviation derived from the PR data suggests that the horizontal variability of rain rates is largely influenced by two factors: surface type (land or ocean) and latitudinal location (tropical or extratropical). Except for light stratiform rain, the land–ocean contrast seems to be the dominant feature for the differences in conditional probability density functions (PDFs) of rain rate. That is, oceanic rain-rate distribution is narrower when the rain rate is low, but becomes broader when the rain rate is high. For light stratiform rain, there is no clear difference among the rain-rate PDFs for rain events over land and ocean. The latitudinal variation of rain-rate PDFs seems to be greater for heavy rain than for light rain. In particular, there is no measurable difference in overland convective rain-rate PDFs between the Tropics and extratropics. Based on three years of observational data, two attributes, fractional rain cover and conditional rain-rate PDFs, are parameterized as a function of 0.25° × 0.25° areal rain rate. These parameterizations are particularly useful in satellite microwave rainfall retrieval and assimilation of satellite microwave radiance data in numerical weather prediction models.
The Evolution of Lee-Wave–Rotor Activity in the Lee of Pike’s Peak under the Influence of a Cold Frontal Passage: Implications for Aircraft Safety
Authors: Darby Lisa S. , Poulos Gregory S. 
Published: October 2006

Abstract
A lee-wave–rotor system interacting with an approaching cold front in the lee of Pike’s Peak near Colorado Springs, Colorado, on 1 April 1997 is studied observationally and numerically. Dynamical effects associated with the approaching cold front caused the amplification of the evolving lee wave and rotor, creating increasingly more hazardous flight conditions for nearby airports. The rapidly evolving winds measured by a Doppler lidar and 915-MHz wind profilers, and simulated by the Regional Atmospheric Modeling System (RAMS), produced light-to-moderate turbulence for a research aircraft making missed approaches at the Colorado Springs Airport during the wave amplification phase. As the cold front approached the foothills, the lee-wave–rotor system ended abruptly, reducing hazardous flight conditions.
The Doppler lidar’s detailed measurements of the lee-wave–rotor system allowed for an evaluation of RAMS ability to capture these complex wind features. Qualitative and quantitative comparisons between the lidar range–height measurements and model x–z cross sections are presented. In a broad sense, the numerical simulations were successful in the prediction of the prefrontal amplification and the postfrontal decay of the waves as measured by the lidar. RAMS also predicted observed wind reversals above the lee waves, which were indicators of breaking wave instability. At times RAMS performed poorly by over- or underpredicting the wind speeds in the lee wave, as well as the horizontal extent of the lee wave or rotor.
Fourier-Ray Modeling of Short-Wavelength Trapped Lee Waves Observed in Infrared Satellite Imagery near Jan Mayen
Authors: Eckermann Stephen D. , Broutman Dave , Ma Jun , Lindeman John 
Published: October 2006

Abstract
A time-dependent generalization of a Fourier-ray method is presented and tested for fast numerical computation of high-resolution nonhydrostatic mountain-wave fields. The method is used to model mountain waves from Jan Mayen on 25 January 2000, a period when wavelike cloud banding was observed long distances downstream of the island by the Advanced Very High Resolution Radiometer Version 3 (AVHRR-3). Surface weather patterns show intensifying surface geostrophic winds over the island at 1200 UTC caused by rapid eastward passage of a compact low pressure system. The 1200 UTC wind profiles over the island increase with height to a jet maximum of ∼60–70 m s−1, yielding Scorer parameters that indicate vertical trapping of any short wavelength mountain waves. Separate Fourier-ray solutions were computed using high-resolution Jan Mayen orography and 1200 UTC vertical profiles of winds and temperatures over the island from a radiosonde sounding and an analysis system. The radiosonde-based simulations produce a purely diverging trapped wave solution that reproduces the salient features in the AVHRR-3 imagery. Differences in simulated wave patterns governed by the radiosonde and analysis profiles are explained in terms of resonant modes and are corroborated by spatial ray-group trajectories computed for wavenumbers along the resonant mode curves. Output from a nonlinear Lipps–Hemler orographic flow model also compares well with the Fourier-ray solution horizontally. Differences in vertical cross sections are ascribed to the Fourier-ray model’s current omission of tunneling of trapped wave energy through evanescent layers.