bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Self‐Report to Predict Ability to Walk 400 Meters in Mobility‐Limited Older Adults
Authors: Sayers Stephen P. , Brach Jennifer S. , Newman Anne B. , Heeren Tim C. , Guralnik Jack M. , Fielding Roger A. 
Published: November 2004

Objectives: To determine whether the ability to walk 400 m could be predicted from self‐reported walking habits and abilities in older adults and to develop an accurate self‐report measure appropriate for observational trials of mobility when functional measures are impractical to collect.Design: Cross‐sectional.Setting: University‐based human physiology laboratory.Participants: One hundred fifty community‐dwelling older men and women (mean age±standard error= 79.8±0.3).Measurements: An 18‐item questionnaire assessing walking habits and ability was administered to each participant, followed by a 400‐m walk test. Ninety‐eight (65%) volunteers were able to complete the 400‐m walk; 52 (35%) were unable. Logistic regression was performed using response items from a questionnaire as predictors and 400‐m walk as the outcome.Results: Three questions (Do you think you could walk one‐quarter of a mile now without sitting down to rest. Because of a health or physical problem, do you have difficulty walking 1 mile? Could you walk up and down every aisle of a grocery store without sitting down to rest or leaning on a cart?) were predictive of 400‐m walking ability and were included in the model. If participants answered all three questions compatible with the inability to walk 400 m, there was a 91% probability that they were unable to walk 400 m, with a sensitivity of 46% and a specificity of 97%.Conclusion: A three‐item self‐report developed in the study was able to accurately predict mobility disability. The utility of this instrument may be in evaluating self‐reported mobility in large observational trials on mobility when functional mobility tasks are impractical to collect.
Psychosocial work factors and dementia
Authors: Seidler A , Nienhaus A , Bernhardt T , Kauppinen T , Elo A-L , Frölich L 
Published: November 2004

Aims:To evaluate the association between psychosocial workplace factors and dementia in a case-control study.Methods:Patients with dementia (aged 55–99 years) were recruited from 23 general practices in the city of Frankfurt-on-Main and surrounding area in 1998–2000. Of these, 108 were suffering from possible Alzheimer’s disease, 59 from possible vascular dementia, and 28 from secondary or unclassified dementia. A total of 229 control subjects (aged 60–94 years) was recruited from the same study region: 122 population controls and 107 dementia-free ambulatory patients. A detailed job history was elicited in a structured personal interview (next-of-kin interviews of cases). Psychosocial work exposure was assigned to cases and control subjects by linking lifetime job histories with a Finnish job-exposure matrix. Data were analysed using logistic regression, to control for age, region, sex, dementia in parents, education, smoking, and the psychosocial network at age 30.Results:There were decreased odds ratios for high challenge at work, high control possibilities at work, and high social demands at work. High risks for error at work revealed a significant positive association with the diagnosis of dementia. Restriction of the analysis to cases with possible Alzheimer’s disease or to cases with possible vascular dementia led to similar results.Conclusions:These results support a role for psychosocial work factors in the aetiology of dementia. As an alternative explanation, people might have chosen jobs with poor work factors due to preclinical dementia, which becomes clinically manifest decades later.
A comparison of methods for the assessment of postural load and duration of computer use
Authors: Heinrich J , Blatter B M , Bongers P M 
Published: November 2004

Aim:To compare two different methods for assessment of postural load and duration of computer use in office workers.Methods:The study population existed of 87 computer workers. Questionnaire data about exposure were compared with exposures measured by a standardised or objective method. Measuring true exposure to postural load consisted of an observation of the workstation design and posture by a trained observer. A software program was used to record individual computer use.Results:Comparing the answers for each item of postural load, six of eleven items showed low agreement (kappa <0.20). For six items the sensitivity was below 50%, while for eight items the specificity was 80% or higher. Computer workers were unable to identify risk factors in their workplace and work posture. On average, computer workers overestimated their total computer use by 1.6 hours. The agreement among employees who reported a maximum of three hours of computer use per day was higher than the agreement among employees with a high duration of computer use.Conclusions:Self-report by means of this questionnaire is not a very reliable method to measure postural load and duration of computer use. This study emphasises that the challenge to develop quick and inexpensive techniques for assessing exposure to postural load and duration of computer use is still open.
An incidence density sampling program for nested case-control analyses
Authors: Richardson D B 
Published: November 2004

Background:The nested case-control design can be a very efficient approach to an epidemiological investigation. In order to obtain unbiased estimates of relative risk, controls should be selected by incidence density sampling, which involves matching each case to a sample of those who are at risk at the time of case occurrence.Methods:This paper presents a simple computer program for incidence density sampling. This program was evaluated using data derived from a cohort study of mortality among workers employed in the nuclear weapons industry. Controls were selected for cases via incidence density sampling; an estimate of the exposure-mortality association was obtained via conditional logistic regression. After 100 iterations of this procedure, the average effect estimate was compared to the risk estimate obtained via proportional hazards regression. The same methods were used to evaluate a program for incidence density sampling that was proposed previously by Pearce in 1989.5Results:Relative risk estimates obtained from nested case-control analyses conducted using the incidence density sampling program reported in this paper are unbiased. In contrast, the program for incidence density sampling proposed by Pearce5tended to produce biased relative risk estimates; the magnitude of bias increased with increasing numbers of controls selected per case.Conclusions:The computer program described in this paper offers a simple approach to incidence density sampling for nested case-control analyses with exact matching on attained age and appropriate enumeration of the pool of eligible controls for each case. This method overcomes problems of bias inherent in a previously proposed program for incidence density sampling.
MONOLITHIC INTEGRATION OF DFB LASERS AND ELECTROABSORPTION MODULATORS USING IN-PLANE QUANTUM ENERGY CONTROL OF MQW STRUCTURES
Authors: AOKI MASAHIRO , SUZUKI MAKOTO , SANO HIROHISA , SASAKI SHINYA , KAWANO TOSHIHIRO , KODERA HIROSHI 
Published: November 2004

This paper describes the fabrication and characteristics of a new multiple-quantum-well (MQW) integrated distributed feedback (DFB) laser diode-electroabsorption (EA) optical modulator for use as the transmitter light source in multigigabit, long-distance optical fiber communications. The device employed a novel integration scheme for active/passive waveguide coupling achieved by controlling the quantum energy of selectively grown MQW structures. This new fabrication technique for photonic integrated circuits (PICs) facilitates smooth, high-quality waveguide coupling between the interconnected guided-wave elements. It is based on the growth rate enhancement or compositional changes in the material of the quantum-well layer grown by selective-area metalorganic vapor phase epitaxy (MOVPE). Good local quantum energy control within a very wide range is shown for simultaneously grown MQW crystals. Moreover, the crystal quality, well/barrier heterointerface, and flatness and uniformity of these selectively grown MQW crystals are found to be as good as those of normally grown crystals. This technique is applied to an MQW integrated DFB laser diode-EA modulator. Superior device performance, including a low threshold and highly efficient lasing properties, as well as high-speed, low-drive-voltage, and low-chirp modulator characteristics are attained due to improved optical coupling, easy fabrication, and sufficient crystal quality of selectively grown MQW structures. 10 Gbit/s data transmission is demonstrated over a 500 km dispersion-shifted single-mode fiber. This combined with long-term device reliability, makes this integration technique more attractive for practical fabrication of semiconductor PICs.
ON LARGE VERTEX SYMMETRIC 2-REACHABLE DIGRAPHS
Authors: COMELLAS F. , FIOL M.A. , GÓMEZ J. 
Published: November 2004

We are interested in the construction of the largest possible vertex symmetric digraphs with the property that between any two vertices there is a walk of length two (that is, they are 2-reachable). Other than a theoretical interest, these digraphs and their generalizations may be used as models of interconnection networks for implementing parallelism. In these systems many nodes are connected with relatively few links and short paths between them and each node may execute, without modifications, the same communication software. On the other hand, a message sent from any vertex reaches all vertices, including the sender, in exactly two steps. In this work we present families of vertex symmetric 2-reachable digraphs with order attaining the upper theoretical bound for any odd degree. Some constructions for even degree are also given.
GENERAL PLANNING METHOD FOR MACHINE COORDINATION AND RENDEZVOUS
Authors: TROVATO KAREN I. 
Published: November 2004

This paper describes a general method for representing and solving planning problems. The framework has well-defined subcomponents to simplify the problem using transforms, define costs over permissible motions, define illegal regions in the transformed space, and efficiently find optimal motions. The method fully exploits any a priori information and also provides a method to augment this information efficiently at runtime. The method is powerful in that it can be used in arbitrarily high dimensional spaces, and has been used to solve non-holonomic problems efficiently and with ease. Examples will be given for moving robotic equipment optimally while avoiding obstacles, for automatically maneuvering a vehicle around obstacles, and for determining alternative rendezvous locations for machinery based on the separate constraints (time, space, fuel, etc.) of each. The rendezvous problem will also give optimal strategies, and precise paths.
The Heuristic Structure of Scientific Knowledge
Authors: Eraña Ángeles , Martínez Sergio 
Published: November 2004

AbstractWe examine two major perspectives in the literature on domain specificity in cognition: in one of them cognitive modules are "intuitive theories"; in the other they are dispositional structures. Both of these positions accept that there is a continuous line from ordinary to scientific reasoning; nevertheless they interpret this continuity differently. We propose an alternative way of understanding the relation between ordinary and scientific reasoning: the continuity thesis holds because heuristic structures play a fundamental role in both types of reasoning. Our main contention is that cognitive modules can be thought of as heuristic structures and that, since science is a complex of practices that embody different heuristic structures, science should be understood as a complex of cognitive modules.
Emergence of Graphing Practices in Scientific Research
Authors: Roth Wolff-Michael 
Published: November 2004

AbstractGraphing has long counted as one of the quintessential process skills that scientists apply independently of particular situations. However, recent expert/expert studies showed that when asked to interpret graphs culled from undergraduate courses of their own disciplines, scientists were far from perfect in providing interpretations that a course instructor would have accepted as correct. Drawing on five years of fieldwork, the present study was designed to investigate graphs and graph-related skills in scientific research. In addition to the fieldwork, a think-aloud protocol was used to elicit scientists' graph interpretations both on familiar and unfamiliar graphs. The analyses show that graph-related skills such as perceiving relevant graphical detail and interpreting the source of this detail emerge in the research process and are related to the scientists' increasing familiarity with a research object, instrumentation, and their understanding of the transformation process that turns raw data into graphs. When scientists do not know the natural object represented in a graph and are unfamiliar with the details of the corresponding data collection protocol, they often focus on graphical features that do not pertain to the phenomenon represented and therefore do not arrive at the correct interpretations. Based on these data, it is proposed that graphs are not only the outcomes of scientific research but also, in important ways, constitute representations that bear metonymic relations to the research context, most importantly to instrumentation, natural phenomenon, and the mathematical transformations used to produce the graphs from the raw data. I draw on the semantics of symbolic systems for articulating competencies and breakdowns in scientists' graphing-related practices.
Effect of a compensated Jaffé creatinine method on the estimation of glomerular filtration rate
Authors: Chan Michael HM , Ng KF , Szeto CC , Lit Lydia CW , Chow KM , Leung CB , Suen Michael WM , Li Phillip KT , Lam Christopher WK 
Published: November 2004

Background: Roche Diagnostics has issued new c-fas calibrators for its automated systems. These produce creatinine values that are more comparable with those obtained by high-performance liquid chromatography. However, this results in an underestimation of measured creatinine at concentrations below 155 μmol/L and an overestimation at concentrations above this value. Methods: Serum and urine creatinine concentrations were prospectively determined on samples from 60 patients using the new (compensated) and old (uncompensated) c-fas calibrators, and Passing-Bablok regression analysis was performed. The regression equations thus determined were then used retrospectively to determine the compensated creatinine results (i.e. those results that would have been obtained using the new calibrator) in those serum and urine samples analysed in the previous year using the old uncompensated c-fas calibrator. The compensated creatinine results were then used to estimate the glomerular filtration rate (GFR) by calculating creatinine clearance. This was done by using the formula: UV/Pt, in which U represents the urinary creatinine concentration (μmol/L), V the urinary collection volume (mL), P the serum creatinine concentration (μmol/L) and t the urinary collection time (min). It was also calculated using the abbreviated Modification of Diet in Renal Disease study group (MDRD) formula. Results: The creatinine clearance as determined using either the UV/Pt calculation or the MDRD formula overestimated GFR by ~30% and ~50%, respectively, in normal individuals with a serum creatinine concentration below 155 μmol/L. However, in patients with mild to moderate renal failure (serum creatinine from 155 to 500 μmol/L), changes in creatinine clearances determined by the two procedures were minimal. Conclusion: When laboratories introduce this new, compensated calibrator into practice, it may be appropriate to discuss its potential impact with clinical staff who monitor patients using creatinine clearance.
On the “General Acceptance” of Handwriting Identification Principles
Authors: Saks MJ , VanderHaar H 
Published: November 2004

Abstract
Informed by the admissibility requirements of the broad and narrow Frye tests as well as Daubert's general acceptance factor, the present study elicited the views of a homogeneous group of forensic document examiners and a heterogeneous group of handwriting scientists regarding the degree to which a set of principles relating to the nature of handwriting and its identification were generally accepted within the respondents' fields. Among forensic document examiners, the greatest agreement was found concerning the process of examination, and somewhat less agreement on other matters. Forensic document examiners and handwriting scientists appear not to agree on the acceptability of most of the propositions.
Does Carcass Enrichment Alter Community Structure of Predaceous and Parasitic Arthropods? A Second Test of the Arthropod Saturation Hypothesis at the Anthropology Research Facility in Knoxville, Tennessee
Authors: Schoenly KG , Shahid SA , Haskell NH , Hall RD 
Published: November 2004

Abstract
In a second test of an arthropod saturation hypothesis, we analyzed if the on-campus Anthropology Research Facility (ARF) at the University of Tennessee, Knoxville, with its 20+ yr history of carcass enrichment, is comparable to non-enriched sites in community structure of predatory and parasitic arthropods that prey upon the sarcosaprophagous fauna. Over a 12-day period in June 1998, using pitfall traps and sweep nets, 10,065 predaceous, parasitic, and hematophagous (blood-feeding) arthropods were collected from freshly euthanized pigs (Sus scrofa L.) placed at ARF and at three surrounding sites various distances away (S2-S4). The community structure of these organisms was comparable in most paired-site tests with respect to species composition, colonization rates, and evenness of pitfall-trap abundances on a per carcass basis. Site differences were found in rarefaction tests of both sweep-net and pitfall-trap taxa and in tests of taxonomic evenness and ranked abundances of sweep-net samples. Despite these differences, no evidence was found that the predatory/parasitic fauna at ARF was impoverished with fewer but larger populations as a result of carcass enrichment. Comparison of the sarcosaprophagous and predatory/parasitic faunas revealed a tighter (and more predictable) linkage between carrion feeders (sarcosaprovores) and their carrion than between carrion feeders and their natural enemies (predators and parasitoids), leading us to conclude that ARF is more representative of surrounding sites with respect to the sarcosaprovore component than to the predatory/parasitic component within the larger carrion-arthropod community.
Autopsy Artifact Created by the Revivant AutoPulse™ Resuscitation Device
Authors: Hart AP , Azar VJ , Hart KR , Stephens BG 
Published: November 2004

Abstract
In certain cases, the evaluation and correct identification of resuscitative artifacts is critical to the correct diagnosis and determination of the cause and manner of death. Resuscitative artifacts can resemble homicidal or accidental injury and thus possibly be misinterpreted. Occasionally, new technologies and/or medical procedures will create original and/or distinctive artifacts. In 2003, the San Francisco Fire Department emergency personnel began field-testing the Revivant AutoPulse™, an automated chest compression device. This device is currently being used in two other counties in the San Francisco Bay Area as well as regions of Florida, Virginia, and Ohio. We present three cases of resuscitative artifact that could be potentially confused with homicidal or accidental injury. These cases illustrate resuscitative artifacts, specifically lateral chest and horizontally oriented upper abdomen cutaneous abrasions created by this automated chest compression device.
Forensic Mitochondrial DNA Analysis of 691 Casework Hairs
Authors: Melton T , Dimick G , Higgins B , Lindstrom L , Nelson K 
Published: November 2004

Abstract
A five year retrospective review of mitochondrial DNA (mtDNA) analysis on 691 casework hairs was carried out. A full or partial mtDNA profile was obtained for ã92% of hairs. With increasing age of the hair, the likelihood of obtaining a full profile decreased, although “mini-primer sets” could often be used to capture a partial profile. With increasing color and diameter of the hair, the likelihood of obtaining a profile increased. Full or partial profiles were obtained on more than 80% of 114 hairs ≤1.0 cm. Mixtures were observed in 8.7% of hairs tested; mixtures increased with the age of the hair and were presumed to be due to exterior surface contamination that could not be sufficiently cleaned prior to extraction, since the overall level of laboratory contamination was low. The frequency of sequence heteroplasmy was 11.4%, and both hot-spot and novel sites were observed. In about one-third of these observations, another sample in the case showed either the same heteroplasmic site or a nucleotide substitution at that site.
A comparison of model performance for six quantitative structure-activity relationship packages that predict acute toxicity to fish
Authors: Moore Dwayne R. J. , Breton Roger L. , MacDonald Drew B. 
Published: November 2004

Abstract
Some regulatory programs rely on quantitative structure-activity relationship (QSAR) models to predict toxic effects to biota. Many currently existing QSAR models can predict the effects of a wide range of substances to biota, particularly aquatic biota. The difficulty for regulatory programs is in choosing the appropriate QSAR model or models for application in their new and existing substances programs. We evaluated model performance of six QSAR modeling packages: Ecological Structure Activity Relationship (ECOSAR), TOPKAT, a Probabilistic Neural Network (PNN), a Computational Neural Network (CNN), the QSAR components of the Assessment Tools for the Evaluation of Risk (ASTER) system, and the Optimized Approach Based on Structural Indices Set (OASIS) system. Using a testing data set of 130 substances that had not been included in the training data sets of the QSAR models under consideration, we compared model predictions for 96-h median lethal concentrations (LC50s) to fathead minnows to the corresponding measured toxicity values available in the AQUIRE database. The testing data set was heavily weighted with neutral organics of low molecular weight and functionality. Many of the testing data set substances also had a nonpolar narcosis mode of action and/or were chlorinated. A variety of statistical measures (correlation coefficient, slope and intercept from a linear regression analysis, mean absolute and squared difference between log prediction and log measured toxicity, and the percentage of predictions within factors of 2, 5, 10, 100, and 1,000 of measured toxicity values) indicated that the PNN model had the best model performance for the full testing data set of 130 substances. The rank order of the remainder of the models depended on the statistical measure employed. TOPKAT also had excellent model performance for substances within its optimum prediction space. Only 37% of the substances in the testing data set, however, fell within this optimum prediction space.