bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dioxin and diabetes mellitus: an analysis of the combined NIOSH and Ranch Hand data
Authors: Steenland K , Calvert G , Ketchum N , Michalek J 
Published: July 2002

OBJECTIVESTo reanalyze in a similar manner the two principal studies of TCDD (tetrachlorodibenzo-p-dioxin) and diabetes in an attempt to reconcile disparate results.METHODSData from 990 United States Air Force veterans (Ranch Hand) and 1275 referents were reanalyzed, and a NIOSH population of 267 chemical workers and 227 referents. The Ranch Hand veterans had lower concentrations of lipid adjusted serum TCDD (median 12 parts per trillion (ppt)) than the NIOSH workers (median 75 ppt) when examined in the late 1980s. An analysis was conducted of the combined data sets, adopting a uniform approach to outcome definition, data analysis, and covariate control.RESULTSThe combined exposed groups did not differ markedly from the combined non-exposed groups for prevalence of diabetes (odds ratio (OR) 1.17, 95% confidence interval (95% CI) 0.92 to 1.48), with no evidence of heterogeneity of exposure effect between studies. Also virtually no difference was found between combined exposed and non-exposed groups in mean fasting serum glucose (difference in log serum glucose 0.002, 95% CI −0.006 to 0.010), and there was little evidence in either study of a dose-response trend for fasting serum glucose. An increasing trend was found (p=0.0001) in prevalence of diabetes with increased TCDD (at the time of examination or at time of last exposure) among the Ranch Hand population, with excess risk largely confined to the highest 8% of the exposed group (>78 ppt serum TCDD), which had an OR of 3.21 (95% CI 1.81 to 5.72) versus those with <10 ppt TCDD. However, no such positive dose-response was found in the NIOSH population.CONCLUSIONSThere was little overall evidence that the exposed workers were at higher risk than the non-exposed workers of diabetes or abnormal fasting glucose. However, the Ranch Hand subjects showed a positive dose-response for diabetes, whereas the more highly exposed NIOSH subjects did not. The reason for the difference in diabetes dose-response trends between the two studies is unknown.
Eosinophilic fasciitis with pulmonary and pleural involvement
Authors: Killen J W W , Swift G L , White R J 
Published: July 2002

Summary
We report a case of eosinophilic fasciitis, with the unusual features of pulmonary and pleural involvement. Similar cases which involve the lungs have been reported after exposure tol-tryptophan, but there is no relevant drug history in this case.
Withdrawing cardiovascular medications at a syncope clinic
Authors: Alsop K , Mac Mahon M 
Published: July 2002

Abstract
It is widely assumed in clinical practice that drug treatment associated with hypotension can result in falls and syncope, but there is actually very little evidence to support this. Therefore the data in all patients whose cardiovascular medications were stopped at a falls/syncope clinic were analysed to see if their symptoms were altered and if renewal of these medications was necessary at subsequent visits.
Of 338 consecutive referrals, cardiovascular medications had been stopped in 65 (19%). At follow up 78% reported improvement in their original presenting symptoms and renewal of medication was not necessary in 77% off antianginals, 69% off antihypertensives, and 36% off antiarrhythmics. It was concluded that adjusting cardiovascular medications could help in the management of falls and syncope and may obviate the need for other treatment. These medications can be stopped in select patients if there is regular monitoring and this should reduce unwanted side effects and costs of these drugs.
Intraoperative glove perforation—single versus double gloving in protection against skin contamination
Authors: Thomas S , Agarwal M , Mehta G 
Published: July 2002

Abstract
Surgeons have the highest risk of contact with patients' blood and body fluids, and breaches in gloving material may expose operating room staff to risk of infections. This prospective randomised study was done to assess the effectiveness of the practice of double gloving compared with single gloving in decreasing finger contamination during surgery.
In 66 consecutive surgical procedures studied, preoperative skin abrasions were detected on the hands of 17.4% of the surgeons. In the double gloving pattern, 32 glove perforations were observed, of which 22 were in the outer glove and 10 in the inner glove. Only four outer glove perforations had matching inner glove perforations, thus indicating that in 82% of cases when the outer glove is perforated the inner glove will protect the surgeon's hand from contamination. The presence of visible skin contamination was also higher in perforation with the single gloving pattern (42.1%) than with the double gloving pattern (22.7%).
An overwhelming majority of glove perforations (83.3%) went unnoticed. Double gloving was accepted by the majority of surgeons, especially with repeated use. It is recommended that double gloves are used routinely in all surgical procedures in view of the significantly higher protection it provides.
THE SIGNATURE TRIALITY OF MAJORANA–WEYL SPACE–TIMES
Authors: DE ANDRADE M. A. , ROJAS M. , TOPPAN F. 
Published: July 2002

In this paper, a general property of field theories with Majorana–Weyl spinors (such as ten-dimensional SYM theories, superstrings, five-branes, etc.) is presented. It is shown that these theories, in a given dimension, admit different formulations in the allowed space–times signatures which are all interconnected by transformations which close the S3 permutation group (S3 duality). Explicit formulas to "translate" a theory from a given signature into another signature, are given. They are conveniently chosen to realize the S3 group. The above construction applies for any dimension d which admit Majorana–Weyl spinors in more than one signature, that is for d ≥ 8. We prove that the S3 duality (valid for any even d ≥ 8) is in consequence of the famous triality property of the 8 dimensions, together with (for d > 8) the mod 8 property of Clifford Γ matrices.
Visualization Study on Chain Structure in Electro-Rheological Fluids
Authors: Tomiuga Takeshi , Okamoto Koji , Madarame Haruki 
Published: July 2002

The electrorheological (ER) effect is known as a phenomenon that shows reversible increase of apparent viscosity by applied electric field. The electric field induces the particle polarization, resulting in the chains between the electrodes. In this study, the ER fluids in the channel with two parallel electrodes were visualized under the pressure flow. The laser light sheet and transparent electrodes were used in the experimental apparatus to visualize the particles under 10wt% concentration. The particle chain structure in the channel was clearly visualized. Under higher voltage condition, particle layers were formed at the neighbor of the electrodes. Processing the visualized images, the effects of the chain structure and the layer on the flow resistance were investigated.
QUANTIFYING LOCAL INSTABILITY AND PREDICTABILITY OF CHAOTIC DYNAMICAL SYSTEMS BY MEANS OF LOCAL METRIC ENTROPY
Authors: WEI MOZHENG 
Published: July 2002

A local metric entropy (LME) is introduced and used as a measure of local instability of chaotic dynamical systems. The predictability time scale of a dynamical system during a given period of time can also be estimated with high accuracy by using the LME. It is shown that LME, at any time during the evolution of a dynamical system, can be calculated as the sum of all the positive local Lyapunov exponents (LEs). This conclusion implies that the positive local LEs represent the rates of local information changes along the directions of their respective Lyapunov vectors. LME does not depend upon the amplitudes nor the configurations of initial perturbations; it depends on the positive local LEs which are intrinsic properties of dynamical systems. In addition, the sum of all the local LEs is proven to be equal to the divergence of phase space. Thus for a general chaotic system at any time, the sum of all the local LEs is equal to the sum of all the local growth rates of either instantaneous optimal modes or normal modes.In analyzing local instability, the performance of LME is evaluated by comparing an instability index with LME, the first local LE, locally largest LE, local growth rates of the dominant instantaneous optimal mode and normal mode. When LME is used to estimate the predictability time scales of systems over specified time periods, it is found that the time scales defined by LME are generally closer to the standard predictability times than the Lyapunov times and Kolmogorov–Sinai times for most cases in the two dynamical systems we have tested. Both the instability index and standard predictability time are defined and calculated through a large number of random errors.
KNUTH–BENDIX FOR GROUPS WITH INFINITELY MANY RULES
Authors: EPSTEIN D. B. A. , SANDERS P. J. 
Published: July 2002

We introduce a new class of groups with solvable word problem, namely groups specified by a confluent set of short-lex-reducing Knuth–Bendix rules which form a regular language. This simultaneously generalizes short-lex-automatic groups and groups with a finite confluent set of short-lex-reducing rules. We describe a computer program which looks for such a set of rules in an arbitrary finitely presented group. Our main theorem is that our computer program finds the set of rules, if it exists, given enough time and space. (This is an optimistic description of our result — for the more pessimistic details, see the body of the paper.) The set of rules is embodied in a finite state automaton in two variables. A central feature of our program is an operation, which we call welding, used to combine existing rules with new rules as they are found. Welding can be defined on arbitrary finite state automata, and we investigate this operation in abstract, proving that it can be considered as a process which takes as input one regular language and outputs another regular language. In our programs we need to convert several nondeterministic finite state automata to deterministic versions accepting the same language. We show how to improve somewhat on the standard subset construction, due to special features in our case. We axiomatize these special features, in the hope that these improvements can be used in other applications. The Knuth–Bendix process normally spends most of its time in reduction, so its efficiency depends on doing reduction quickly. Standard data structures for doing this can become very large, ultimately limiting the set of presentations of groups which can be so analyzed. We are able to give a method for rapid reduction using our much smaller two variable automaton, encoding the (usually infinite) regular language of rules found so far. Time taken for reduction in a given group is a small constant times the time taken for reduction in the best schemes known (see [5]), which is not too bad since we are reducing with respect to an infinite set of rules, whereas known schemes use a finite set of rules. We hope that the method described here might lead to the computation of automatic structures in groups for which this is currently infeasible. Some proofs have been omitted from this paper in the interests of brevity. Full details are provided in [4].
Principles of database buffer management
Authors: Effelsberg Wolfgang , Haerder Theo 
Published: July 2002

This paper discusses the implementation of a database buffer manager as a component of a DBMS. The interface between calling components of higher system layers and the buffer manager is described; the principal differences between virtual memory paging and database buffer management are outlined; the notion of referencing versus addressing of database pages is introduced; and the concept of fixing pages in the buffer to prevent uncontrolled replacement is explained.
Three basic tasks have to be performed by the buffer manager: buffer search, allocation of frames to concurrent transactions, and page replacement. For each of these tasks, implementation alternatives are discussed and illustrated by examples from a performance evaluation project of a CODASYL DBMS.
Constructing 1-writer multireader multivalued atomic variables from regular variables
Authors: Haldar S. , Vidyasankar K. 
Published: July 2002

A simple wait-free construction of 1-writer multireader multivalued atomic variable from multireader regular variables is presented in this paper. A key point of the construction is the use of an elegant forwarding technique to overcome the new-old inversion property inherent in regular variables.
Another construction, using a different forwarding technique, is also given. This technique is a refinement of one proposed in the literature.
Formal correctness proofs for both the constructions are short and easy to follow.
Extending the database relational model to capture more meaning
Authors: Codd E. F. 
Published: July 2002

During the last three or four years several investigators have been exploring “semantic models” for formatted databases. The intent is to capture (in a more or less formal way) more of the meaning of the data so that database design can become more systematic and the database system itself can behave more intelligently. Two major thrusts are clear.
In this paper we propose extensions to the relational model to support certain atomic and molecular semantics. These extensions represent a synthesis of many ideas from the published work in semantic modeling plus the introduction of new rules for insertion, update, and deletion, as well as new algebraic operators.
Scheduling Parallel Computations
Authors: Reiter Raymond 
Published: July 2002

A model for parallel computations is given as a directed graph in which nodes represent elementary operations, and branches, data channels. The problem considered is the determination of an admissible schedule for such a computation; i.e. for each node determine a sequence of times at which the node initiates its operation. These times must be such that each node, upon initiation, is assured of having the necessary data upon which to operate. Necessary and sufficient conditions that a schedule be admissible are given. The computation rate of a given admissible schedule is defined and is shown to have a limiting value 1/π where π is a parameter dependent upon the cycles in the graph. Thus, the computation cannot proceed at a rate exceeding 1/π. For γ ≥ π, the class of all periodic admissible schedules with period γ is characterized by the solution space of a certain system of linear inequalities. In particular, then, the maximum computation rate of 1/π is attainable under a periodic admissible schedule with period π. A class of all-integer admissible schedules is given. Finally, an algorithm is given for the determination of the number of initiations of each node in the graph defining a parallel computation.
An example for a system of difference equations is given in detail.
Consumer Health Plan Choice: Current Knowledge and Future Directions
Authors: Scanlon Dennis P. , Chernew Michael , Lave Judith R. 
Published: July 2002

▪ Abstract  A keystone of the competitive strategy in health insurance markets is the assumption that “consumers” can make informed choices based on the costs and quality of competing health plans, and that selection effects are not large. However, little is known about how individuals use information other than price in the decision making process. This review summarizes the state of knowledge about how individuals make choices among health plans and outlines an agenda for future research. We find that the existing literature on health plan choice is no longer sufficient given the widespread growth and acceptance of managed care, and the increased proportion of consumers' income now going toward the purchase of health plans. Instead, today's environment of health plan choice requires better understanding of how plan attributes other than price influence plan choice, how other variables such as health status interact with plan attributes in the decision making process, and how specific populations differ from one another in terms of the sensitivity of their health plan choices to these different types of variables.
The Effects of Frontal Lobe Lesions on Goal Achievement in the Water Jug Task
Authors: Colvin Mary Kathryn , Dunbar Kevin , Grafman Jordan 
Published: July 2002

Abstract
Patients with prefrontal cortex lesions are impaired on a variety of planning and problem-solving tasks. We examined the problem-solving performance of 27 patients with focal frontal lobe damage on the Water Jug task. The Water Jug task has never been used to assess problem-solving ability in neurologically impaired patients nor in functional neuroimaging studies, despite sharing structural similarities with other tasks sensitive to prefrontal cortex function, including the Tower of Hanoi, Tower of London, and Wisconsin Card Sorting Task (WCST). Our results demonstrate that the Water Jug task invokes a unique combination of problem-solving and planning strategies, allowing a more precise identification of frontal lobe lesion patients' cognitive deficits. All participants (patients and matched controls) appear to be utilizing a hill-climbing strategy that does not require sophisticated planning; however, frontal lobe lesion patients (FLLs) struggled to make required “counterintuitive moves” not predicted by this strategy and found within both solution paths. Left and bilateral FLLs were more impaired than right FLLs. Analysis of the left hemisphere brain regions encompassed by the lesions of these patients found that poor performance was linked to left dorsolateral prefrontal cortex damage. We propose that patients with left dorsolateral prefrontal cortex lesions have difficulty making a decision requiring the conceptual comparison of nonverbal stimuli, manipulation of select representations of potential solutions, and are unable to appropriately inhibit a response in keeping with the final goal.
GABA-ergic Modulation of Prefrontal Spatio-temporal Activation Pattern during Emotional Processing: A Combined fMRI/MEG Study with Placebo and Lorazepam
Authors: Northoff Georg , Witze Thomas , Richter Andre , Gessner Matthias , Schlagenhauf Florian , Fell Jürgen , Baumgart Frank , Kaulisch Thomas , Tempelmann Claus , Heinzel Alexander , Kötter Rolf , Hagner Tilman , Barge Bela , Hinrichs Hermann , Bogerts Bernhard , Scheich Henning , Heinze Hans-Jochen 
Published: July 2002

AbstractVarious prefrontal cortical regions have been shown to be activated during emotional stimulation, whereas neurochemical mechanisms underlying emotional processing in the prefrontal cortex remain unclear. We therefore investigated the influence of the GABA-A potentiator lorazepam on prefrontal cortical emotional—motor spatio-temporal activation pattern in a combined functional magnetic resonance imaging/magnetoencephalography study. Lorazepam led to the reversal in orbito-frontal activation pattern, a shift of the early magnetic field dipole from the orbito-frontal to medial prefrontal cortex, and alterations in premotor/motor cortical function during negative and positive emotional stimulation. It is concluded that negative emotional processing in the orbito-frontal cortex may be modulated either directly or indirectly by GABA-A receptors. Such a modulation of orbito-frontal cortical emotional function by lorazepam has to be distinguished from its effects on cortical motor function as being independent from the kind of processing either emotional or nonemotional.
Contributions of the Prefrontal Cortex and Basal Ganglia to Set Shifting
Authors: Ravizza Susan M. , Ciranni Michael A. 
Published: July 2002

Abstract
Impairments of set shifting have been associated with damage to both the prefrontal cortex (PFC) and to the basal ganglia. The purpose of these experiments was to determine whether damage to the PFC was associated with shifting impairments per se or whether any switching deficits could be attributed to a reduction of working memory capacity. In contrast, shifting impairments were expected for Parkinson patients regardless of memory load, given that these patients seem to have no cognitive deficits other than when having to shift set. To vary working memory demands, a cue to the relevant dimension (letter or shape) in an odd-man-out task was presented or withheld. Pathology to prefrontal areas associated with normal aging was not linked to shifting deficits when working memory load was reduced in a comparison of older and younger adults (Experiment 1). In contrast, set-shifting abilities were still impaired for stroke patients with prefrontal damage regardless of working memory demands (Experiment 2). Parkinson patients were relatively unimpaired on this task (Experiment 2), but began to display shifting deficits when response competition was present in the display (Experiment 3).
Inserting the Presence of Mind into a Philosophy of Presence: A Response to Sheridan and Mantovani and Riva
Authors: Biocca Frank 
Published: July 2002

This article considers the following question: What is the best foundation for a theory of presence? After establishing criteria for a philosophy of presence, the article applies these criteria to a set of articles on the philosophy of presence by Sheridan (1999), Mantovani and Riva (1999), and others. Although we share common goals, it is suggested that these articles advance a philosophy of presence that may be ill suited to support theory and research on presence. Several arguments are advanced to support this judgment. J. J. Gibson's work may be misinterpreted to accommodate relativistic models of physical reality. By directly referencing Gibson's writings, especially his concepts of ecological invariants, the article details how Gibson's work could not be used to support cultural, relativistic, or “engineering” arguments about “different realities”, perceptual or otherwise, without significant modification of Gibson's work and violation of his apparent intent. Another source of problems for a philosophy of presence is traced. There appears to be a terminological and theoretical confusion about the difference between epistemology and ontology. This article proposes that ontological debates about divine presence represented by these authors may be inappropriate or sterile for three reasons: (1) although perceptual presence (that is, phenomenal states of distal attribution) and “divine presence” (that is, immanence of God) share the term presence, they are fundamentally different philosophical problems; (2) the concept of divine presence and Sheridan's associated “estimation paradigm” is framed at such a level of generality to be incapable of supporting specific, actionable, and researchable theories about perceptual presence; and (3) any theory about “virtual reality”, a technology with a misleading oxymoronic term, provides no more ontological insight into reality than does theory and research on any other communication medium such as photography, film, or sound recording. Finally, the article proposes a remedy. The philosophy of presence might be most fruitfully approached via the philosophy of mind. Specifically, it is suggested that presence opens the door to related problems in the science of human consciousness, notably the mind-body problem. The article also suggests that the problem of presence bridges the philosophy of mind and the philosophy of technology on the issue of mediated embodiment, that is, the fuzzy boundary between the body and technological extensions of the body.