bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aborted sudden cardiac death: a clinical perspective
Authors: Mazeika P 
Published: July 2002

Abstract
Sudden cardiac death in the community remains a major public health problem. The purpose of this article is to outline the epidemiology, pathophysiology, and immediate treatment of the cardiac arrest victim. The subsequent in-hospital diagnostic evaluation and management will then be discussed with an emphasis on the role of the implantable cardioverter-defibrillator. A systematic and evidence based approach should help to optimize patient care.
Living kidney donation: a comparison of laparoscopic and conventional open operations
Authors: Waller J R , Hiley A L , Mullin E J , Veitch P S , Nicholson M L 
Published: July 2002

Abstract
Laparoscopic donor nephrectomy has the potential to lessen the burden placed on live kidney donors. This study describes the first British comparison of donor morbidity and recovery following conventional open donor nephrectomy (ODN) and laparoscopic donor nephrectomy (LDN).
An initial series of LDN (n=20) was compared to a historical control group of ODN (n=34). Laparoscopic operations were performed via a transperitoneal approach, the kidney being removed through a 6–12 cm Pfannensteil incision. Open operations were performed using a retroperitoneal flank approach with resection of the 12th rib. Postoperatively, donors were managed with a patient controlled analgesia system.
LDN was associated with shorter mean (SD) inpatient stay (6 (2) v 4 (1) days; p=0.0001) and lower parenteral narcotic requirements (morphine 179 (108) v 67 (54) mg; p=0.0001). Laparoscopic donors started driving their cars sooner (2 (1.5) v 6 (4) weeks; p=0.0001) and returned to work more quickly (5 (3) v 12 (6) weeks; p=0.0001) than open nephrectomy donors. There were no differences in recipient serum creatinine levels at three months post-transplant but two recipients of transplant kidneys retrieved laparoscopically (10%) developed ureteric obstruction, whereas this complication did not occur after ODN (p=0.13).
LDN is associated with less postoperative pain and a substantial improvement in donor recovery times. It is not yet clear whether or not the outcome of the recipient kidney transplants are the same after ODN and LDN and much more experience is required before the place of this new technique can be defined.
Processing time-constrained aggregate queries in CASE-DB
Authors: Hou Wen-Chi , Ozsoyoglu Gultekin 
Published: July 2002

In this paper, we present an algorithm to strictly control the time to process an estimator for an aggregate relational query. The algorithm implemented in a prototype database management system, called CASE-DB, iteratively samples from input relations, and evaluates the associated estimator until the time quota expires.
In order to estimate the time cost of a query, CASE-DB uses adaptive time cost formulas. The formulas are adaptive in that the parameters of the formulas can be adjusted at runtime to better fit the characteristics of a query. To control the use of time quota, CASE-DB adopts the one-at-a-time-interval time control strategy to make a tradeoff between the risks of overspending and the overhead, finally, experimental evaluation of the methodology is presented.
Design of an external schema facility to define and process recursive structures
Authors: Clemons Eric K. 
Published: July 2002

The role of the external schema is to support user views of data and thus to provide programmers with easier data access. This author believes that an external schema facility is best based on hierarchies, both simple and recursive. After a brief introduction to an external schema facility to support simple hierarchical user views, the requirements for a facility for recursive hierarchies are listed and the necessary extensions to the external schema definition language are offered.
Functions that must be provided for generality in definition are node specification and node control. Tree traversal functions must be provided for processing. Definitions of each and examples of use are presented.
Analysis of a heuristic for full trie minimization
Authors: Comer Douglas 
Published: July 2002

A trie is a distributed-key search tree in which records from a file correspond to leaves in the tree. Retrieval consists of following a path from one root to a leaf, where the choice of edge at each node is determined by attribute values of the key. For full tries, those in which all leaves lie at the same depth, the problem of finding an ordering of attributes which yields a minimum size trie is NP-complete.
This paper considers a “greedy” heuristic for constructing low-cost tries. It presents simulation experiments which show that the greedy method tends to produce tries with small size, and analysis leading to a worst case bound on approximations produced by the heuristic. It also shows a class of files for which the greedy method may perform badly, producing tries of high cost.
Restructuring for large databases
Authors: Navathe Shamkant B. , Fry James P. 
Published: July 2002

The development of a powerful restructuring function involves two important components—the unambiguous specification of the restructuring operations and the realization of these operations in a software system. This paper is directed to the first component in the belief that a precise specification will provide a firm foundation for the development of restructuring algorithms and, subsequently, their implementation. The paper completely defines the semantics of the restructuring of tree structured databases.
The delineation of the restructuring function is accomplished by formulating three different levels of abstraction, with each level of abstraction representing successively more detailed semantics of the function.
At the first level of abstraction, the schema modification, three types are identified—naming, combining, and relating; these three types are further divided into eight schema operations. The second level of abstraction, the instance operations, constitutes the transformations on the data instances; they are divided into group operations such as replication, factoring, union, etc., and group relation operations such as collapsing, refinement, fusion, etc. The final level, the item value operations, includes the actual item operations, such as copy value, delete value, or create a null value.
An information-theoretic approach to text searching in direct access systems
Authors: Barton Ian J. , Creasey Susan E. , Lynch Michael F. , Snell Michael J. 
Published: July 2002

Using direct access computer files of bibliographic information, an attempt is made to overcome one of the problems often associated with information retrieval, namely, the maintenance and use of large dictionaries, the greater part of which is used only infrequently. A novel method is presented, which maps the hyperbolic frequency distribution of text characteristics onto a rectangular distribution. This is more suited to implementation on storage devices.
This method treats text as a string of characters rather than words bounded by spaces, and chooses subsets of strings such that their frequencies of occurrence are more even than those of word types. The members of this subset are then used as index keys for retrieval. The rectangular distribution of key frequencies results in a much simplified file organization and promises considerable cost advantages.
Design of tree structures for efficient querying
Authors: Casey R. G. 
Published: July 2002

A standard information retrieval operation is to determine which records in a data collection satisfy a given query expressed in terms of data values. The process of locating the desired responses can be represented by a tree search model. This paper poses an optimization problem in the design of such trees to serve a well-specified application. The problem is academic in the sense that ordinarily the optimal tree cannot be implemented by means of practical techniques. On the other hand, it is potentially useful for the comparison it affords between observed performance and that of an intuitively attractive ideal search procedure.
As a practical application of such a model this paper considers the design of a novel tree search scheme based on a bit vector representation of data and shows that essentially the same algorithm can be used to design either an ideal search tree or a bit-vector tree. An experimental study of a small formatted file illustrates the concepts.
On the meaning of names in programming systems
Authors: Fraser A. G. 
Published: July 2002

It is assumed that there is a similarity of function between the data names of a programming language and the file names of an operating system. The two functions are discussed in terms of the same basic concepts in order to identify the extent to which they overlap. It is suggested that there is some similarity between the idea of a file directory and a storable object of type context. Manipulations with contexts are then discussed at length.
It is noted that there is a simple extension of Church's λ notation that deals nicely with these ideas of context manipulation. Whereas a function can be regarded as the abstraction based upon the first two terms of the expression λ(namelist)(expression)(valuelist), it is found that a context can be viewed as an abstraction based upon the first two terms in the equivalent expression μ(namelist)(valuelist)(expression).
APAREL—A parse-request language
Authors: Balzer R. M. , Farber D. J. 
Published: July 2002

APAREL is described: this language is an extension to an algorithmic language (PL/I) that provides the pattern-matching capabilities normally found only in special purpose languages such as SNOBOL4 and TMG. This capability is provided through parse-requests stated in a BNF-like format. These parse-requests form their own programming language with special sequencing rules. Upon successfully completing a parse-request, an associated piece of PL/I code is executed. This code has available for use, as normal PL/I strings, the various pieces (at all levels) of the parse. It also has available, as normal PL/I variables, the information concerning which of the various alternatives were successful. Convenient facilities for multiple input-output streams, the initiation of sequences of parse-requests as a subroutine, and parse-time semantic checks are also included.
APAREL has proven convenient in building a powerful SYNTAX and FUNCTION macro system, an algebraic language preprocessor debugging system, an on-line command parser, a translator for Dataless Programming, and as a general string manipulator.
Male-Killing, Nematode Infections, Bacteriophage Infection, and Virulence of Cytoplasmic Bacteria in the GenusWolbachia
Authors: Stevens Lori , Giordano Rosanna , Fialho Roberto F. 
Published: July 2002

▪ Abstract  Wolbachia bacteria are cytoplasmic endosymbionts with a wide range of effects on their hosts and are known to infect two major invertebrate groups, arthropods and nematodes. In arthropods Wolbachia alter host reproduction, causing unidirectional and bidirectional cytoplasmic incompatibility, parthenogenesis, feminization, and embryonic male killing. Wolbachia variation in reproductive effects is indicative of a high degree of evolutionary plasticity. As many as 75% of arthropods may be infected with Wolbachia, which in addition to affecting reproduction, can also directly affect host fitness by either increasing or decreasing survival and fecundity. We review the dynamics of embryonic male-killing, including effects on insect mating behavior, as well as the distribution and implication of Wolbachia infections in filarial nematodes.Arthropod host–Wolbachia phylogenies are not congruent, which is suggestive of horizontal transmission. The opposite has been shown in nematode-Wolbachia phylogenies, indicative of long-term association and vertical transmission. Multiple levels of parasitism within arthropods may promote horizontal transmission. Bacteriophage WO has recently been identified and is found in all Wolbachia-infected insect hosts so far examined. Extensive horizontal transmission of the phage occurs between different Wolbachia strains within a host as well as between Wolbachia in different hosts. The phage genome may carry genes important in determining both the effect of Wolbachia on arthropod host reproduction and host fitness and fecundity. The extensive horizontal transmission of the phage may explain the plasticity of Wolbachia's effect on arthropod hosts.
FACTORS AFFECTING OUTCOME AFTER RECOVERY FROM MYOCARDIAL INFARCTION
Authors: Woo, M.D Kam S. , White, M.B Harvey D. 
Published: July 2002

▪ Abstract  Patients surviving acute myocardial infarction are susceptible to heart failure, recurrence of angina, reinfarction, arrhythmias, and sudden cardiac death. Most deaths occur in the first six months after infarction. Advancing age is the most important nonmodifiable prognostic factor for long-term prognosis, whereas left ventricular function assessed clinically or measured as either ejection fraction or end-systolic volume is the most important modifiable factor. Other significant long-term prognostic factors include: postinfarction angina at rest, inducible ischemia during exercise testing with or without radioisotope imaging, severity and extent of coronary artery disease, patency of the infarct-related artery, late ventricular arrhythmias, decreased heart rate variability, cigarette smoking, hypercholesterolemia, and diabetes mellitus. Identification of these adverse prognostic factors permits risk stratification and enables physicians to determine the most appropriate and cost-effective treatment. Most patients should have a stress test for inducible ischemia and a noninvasive (echo or radionuclide) assessment of left ventricular function. For high-risk patients such as those with prior infarction, heart failure, early postinfarction angina, or frequent late ventricular arrhythmias, coronary angiography and ventriculography prior to discharge are recommended. Assessment of late potentials and heart rate variability will help identify a subgroup of patients at risk for ventricular arrhythmias and cardiac death. However, a more accurate prediction of reinfarction is not possible at present, and no reliable test for atherosclerotic plaque instability has been developed.
Topographic and Temporal Indices of Vowel Spectral Envelope Extraction in the Human Auditory Cortex
Authors: Diesch Eugen , Luce Thomas 
Published: July 2002

Abstract
The audirory-evoked neuromagnetic field elicited by single vowel formants and two-formant vowels was recorded under active listening conditions using a 37-channel magnetometer. There were three single formants with formant with a formant frequency of 200, 400, and 800 Hz, another single fromant with a fromant frequency of 2600 Hz, and three vowels that were constructed by linear superimposition of the high-onto one of the low-frequency formants. P50m and N100m latency values were inversely correlated with the formant frequency of single location was obtained along the postero-anterior axiz, which is orthogonal to the well-established latero-medial tonotopic gradient. Regardless of whether single formants or first formants of vowels were considered N100m sources were more anterior and sustained field sources wre more posterior for higher-frequency than for lower-frequency formants. The velocity of the apparent posterior-to-anterior movement across cortical sorface of N100m sources first reported by Rogers et al. [Rogers, R.L., Papanicolaou, A.C., Baumann, S.B., Saydjari,C., & Eisenberg, H.M. (1990). Neuromagnetic evidence of a dynamic excitation pattern generating the N100 auditory response. Electroencephalography and Clinical Neurophy-siology,77,237-240] decreased as a function of latency. The amount of deceleration was positively correlated with formant frequency. responses to the vowels were superadditive, indicating that the processes elicited by the constituents of composite stumuli interact at one or more stages of the afferent auditory pathway. Such interaction may account for the absence of a lateral-to-medial tonotopic mapping of first formant frequency. The source topography found may reflect activity in auditory fields adjacent to AI with the strenght of the contribution varying with formant frequency. Altematively, it may reflect sharpness-of-tuning and inhbitory response-area asymmetry gradients along isofrequency stripes within AI. Either alternative may be interpreted in terms of a sprctral blurring mechanism that abstracts spectral envelope information form the details of spectral composition, an important step towards the formation of invariant phonetic percepts.
An Empirical Explanation of the Chubb Illusion
Authors: Lotto R. Beau , Purves Dale 
Published: July 2002

Abstract
The perceived difference in brightness between elements of a patterned target is diminished when the target is embedded in a similar surround of higher luminance contrast (the Chubb illusion). Here we show that this puzzling effect can be explained by the degree to which imperfect transmittance is likely to have affected the light that reaches the eye. These observations indicate that this ‘illusion’ is yet another signature of the fundamentally empirical strategy of visual perception, in this case generated by the typical influence of transmittance on inherently ambiguous stimuli.
Visual Priming Within and Across Symbolic Format Using a Tachistoscopic Picture Identification Task: A PET Study
Authors: Lebreton Karine , Desgranges Béatrice , Landeau Brigitte , Baron Jean-Claude , Eustache Francis 
Published: July 2002

Abstract
The present work was aimed at characterizing picture priming effects from two complementary behavioral and functional neuroimaging (positron emission tomography, PET) studies. In two experiments, we used the same line drawings of common living/nonliving objects in a tachistoscopic identification task to contrast two forms of priming. In the within-format priming condition (picture-picture), subjects were instructed to perform a perceptual encoding task in the study phase, whereas in the cross-format priming condition (word-picture), they were instructed to perform a semantic encoding task. In Experiment 1, we showed significant priming effects in both priming conditions. However, the magnitude of priming effects in the same-format/perceptual encoding condition was higher than that in the different-format/semantic encoding condition, while the recognition performance did not differ between the two conditions. This finding supports the existence of two forms of priming that may be subserved by different systems. Consistent with these behavioral findings, the PET data for Experiment 2 revealed distinct priming-related patterns of regional cerebral blood flow (rCBF) decreases for the two priming conditions when primed items were compared to unprimed items. The same-format priming condition involved reductions in cerebral activity particularly in the right extrastriate cortex and left cerebellum, while the different-format priming condition was associated with rCBF decreases in the left inferior temporo-occipital cortex, left frontal regions, and the right cerebellum. These results suggest that the extrastriate cortex may subserve general aspects of perceptual priming, independent of the kind of stimuli, and that the right part of this cortex could underlie the same-format-specific system for pictures. These data also support the idea that the cross-format/semantic encoding priming for pictures represents a form of lexico-semantic priming subserved by a semantic neural network extending from left temporo-occipital cortex to left frontal regions. These results reinforce the distinction between perceptual and conceptual priming for pictures, indicating that different cerebral processes and systems are implicated in these two forms of picture priming.
Wada Testing Reveals Frontal Lateralization for the Memorization of Words and Faces
Authors: Kelley W. M. , Ojemann J. G. , Wetzel R. D. , Derdeyn C. P. , Moran C. J. , Cross D. T. , Dowling J. L. , Miller J. W. , Petersen S. E. 
Published: July 2002

Abstract
Neuroimaging studies have suggested that specific regions of the frontal and medial temporal cortex are engaged during memory formation. Further, there is specialization across these regions such that verbal materials appear to preferentially engage the left regions while nonverbal materials primarily engage the right regions. An open question, however, has been to what extent frontal regions contribute to successful memory formation. The present study investigates this question using a reversible lesion technique known as the Wada test. Patients memorized words and unfamiliar faces while portions of their left and right hemispheres were temporarily anesthetized with sodium amytal. Subsequent memory tests revealed that faces were remembered better than words following left-hemisphere anesthesia, whereas words were remembered better than faces following right-hemisphere anesthesia. Importantly, inspection of the circulation affected by the amytal further suggests that these memory impairments did not result from direct anesthetization of the medial temporal regions. Taken in the context of the imaging findings, these results suggest that frontal regions may also contribute to memory formation in normal performance.
Semantic Category Interference in Overt Picture Naming: Sharpening Current Density Localization by PCA
Authors: Maess Burkhard , Friederici Angela D. , Damian Markus , Meyer Antje S. , Levelt Willem J. M. 
Published: July 2002

Abstract
The study investigated the neuronal basis of the retrieval of words from the mental lexicon. The semantic category interference effect was used to locate lexical retrieval processes in time and space. This effect reflects the finding that, for overt naming, volunteers are slower when naming pictures out of a sequence of items from the same semantic category than from different categories. Participants named pictures blockwise either in the context of same-or mixed-category items while the brain response was registered using magnetoencephalography (MEG). Fifteen out of 20 participants showed longer response latencies in the same-category compared to the mixed-category condition. Event-related MEG signals for the participants demonstrating the interference effect were submitted to a current source density (CSD) analysis. As a new approach, a principal component analysis was applied to decompose the grand average CSD distribution into spatial subcomponents (factors). The spatial factor indicating left temporal activity revealed significantly different activation for the same-category compared to the mixed-category condition in the time window between 150 and 225 msec post picture onset. These findings indicate a major involvement of the left temporal cortex in the semantic interference effect. As this effect has been shown to take place at the level of lexical selection, the data suggest that the left temporal cortex supports processes of lexical retrieval during production.