bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementing phrase-structure productions in PL/I
Authors: Irwin Larry
Published: July 2002

A method is described for implementing the productions of a context-free phrase structure grammar in a PL/I procedure whose structure and statements parallel the structure and notation of the grammar.
On the representation of symmetric polynomials
Authors: McKay J. K. S.
Published: July 2002

Relations are given between certain symmetric polynomials in the light of the theory of the symmetric group. Such an approach unifies earlier work and lends insight to previously published work by Aaron Booker. A generalization of Graeffe's root-squaring technique for the determination of the roots of a polynomial is suggested.
Changes in government procurement policies
Authors: Titus James P.
Published: July 2002

Several years ago there was an attempt in Washington to place the selection of government computers in a central, highly placed office. Individual government agencies, led by the Department of Defense, successfully beat back this attempt. Today, two years later, it looks as though other forms of centralization are being worked into the government fabric at lower levels, one in the Department of Defense, another in the General Services Administration.
A multiprogramming environment for online data acquistion and analysis
Authors: Lockemann Peter C. , Knutsen W. Dale
Published: July 2002

An experimental system for acquisition and analysis of large bodies of data derived from scientific experiments is described. Its architecture and implementation is largely based on certain objectives and characteristics of a general data analysis scheme. Early applications have been oriented towards the investigation of data obtained in biological research. Some of the problems encountered by the chosen approach are discussed.
Tests on a computer method for constructing school timetables
Authors: Csima J. , Gotlieb C. C.
Published: July 2002

A previously proposed computer method for constructing timetables, based on an iteration involving Boolean matrices, is described. In limited tests the method has successfully produced timetables on every trial. References are given which relate the timetable problem to theorems on matrices of zeros and ones, and to theorems on bipartite graphs. Some problems of applying the method to constructing timetables in real situations are noted.
Programming Languages: GPL, a truly general purpose language
Authors: Garwick Jan V.
Published: July 2002

A truly general purpose programming language, GPL, is described which contains facilities for constructing (within the language) new data types as well as facilities for operations performed upon them. The basic language is minimal in the sense that no basic element can be derived from the others with high efficiency in the object programs. Constructs like the ALGOL 60 for-statements, and if-statements are not basic; they are special types of procedures. New “symbols” (underlined words in ALGOL 60) are implicitly defined by usage in other declarations. As part words are definable, packed words are handled as easily as full words. “Address” variables (pointers) are included in full generality.
Numerical Analysis: Numerical solution of a thin plate heat transfer problem
Authors: Stewart G. W. , Lick Dale W.
Published: July 2002

The numerical solution of a system of linear equations resulting from a discrete approximation to a thin plate heat transfer problem is considered. The slow convergence of point iterative methods is analyzed and shown to be caused by one of the boundary conditions. The difficulty may be removed by a standard line iterative technique.
Techniques for the simulation of computer logic
Authors: Breuer Melvin A.
Published: July 2002

A special operator calculus developed by Hartley in 1956 together with a new mapping scheme has been found to be efficient in programming analysis of variance for multifactor experiments. The operator calculus and the mapping scheme are described in detail.
A computer analysis method for thermal diffusion in biochemical systems
Authors: Davids Norman , Berger Robert L.
Published: July 2002

In the thermal detection of rapid biochemical reactions it is necessary to correct the temperature data for transient heat conduction losses in a cylindrical calorimeter. To handle the complexities arising from varying thermal-relaxation times of concentric insulating layers, a computer program was developed which gives the temperature distribution of the system as a function of radius and time. This distribution is corrected at each step by a subroutine which calculates the instantaneous chemical state of the reaction, as well as the heat produced by this reaction.

The program is based on a direct statement of Fourier's law of heat conduction and the chemical rate equation to provide a “bookkeeping law” to follow the reactants and the flow of heat packets, in such a way that the computer continually stores the heat distribution. A computer analysis method is here regarded as one in which the physical laws of a process are used explicitly in the program. Usually this results in bypassing much of the mathematical procedures conventionally used.
Patent protection of computer programs
Authors: Jacobs Morton C.
Published: July 2002

Recently, the computer industry has been exploring anew the question of whether programs for operating an electronic digital computer are or should be patentable.
A note on storage of strings
Authors: Berztiss A. T.
Published: July 2002

A method for storing strings is described which uses blocks of indefinite size, and is therefore completely dynamic. Its relation to similar schemes is discussed.
File-handling within FORTRAN
Authors: Harrison Malcolm C.
Published: July 2002

This note describes some FORTRAN subroutines to facilitate handling of tape files. They allow symbolic naming or information files, without violating the casual scientific programmer's idea of simplicity. Some comments on two years use of these subroutines are given.
Negative and zero subscripts in Fortran II programming for the IBM 1620
Authors: Garber M. J.
Published: July 2002

The requirement that subscripts be unsigned integers creates some inconvenience in FORTRAN programming for summarization of completed questionnaires in which the responses may be scaled beginning at zero.
Compilation for two computers with NELIAC
Authors: Masterson Kleber S.
Published: July 2002

NELIAC, a compiler based on ALGOL, was developed at the U. S. Navy Electronics Laboratory, San Diego, California, as a “bootstrap” compiler for the Remington Rand Univac COUNTESS computer. This compiler was used to generate a version of itself which, running as a COUNTESS program, generated machine code for the Control Data Corporation CDC-1604 computer. This second compiler was then used to generate a version of NELIAC for the CDC-1604. All three versions of NELIAC accepted essentially identical input language.
Report on proposed American standard flowchart symbols for information processing
Authors: Rossheim Robert J.
Published: July 2002

This paper presents the essential contents of the Proposed American Standard Flowchart Symbols for Information Processing. This is the first proposed standard prepared by Subcommittee X3.6 on Problem Description and Analysis of the American Standards Association (ASA).
Parallel shared-memory simulator performance for large ATM networks
Authors: Unger Brian , Xiao Zhonge , Cleary John , Tsai Jya-Jang , Williamson Carey
Published: July 2002

A performance comparison between an optimistic and a conservative
parallel simulation kernel is presented. Performance of the parallel kernels is also compared to a central-event-list sequential kernel. A spectrum of ATM network and traffic scenarios representative of those used by ATM networking researchers are used for the comparison. Experiments are conducted with a cell-level ATM network simulator and an 18-processor SGI PowerChallenge shared-memory multiprocessor.

The results show the performance advantages of parallel simulation ove r sequential simulation for ATM networks. Speedups of 4-5 relative to a fast sequential kernel are achieved on 16 processors for several large irregular ATM benchmark scenarios and the optimistic kernel achieves 2 to 5 times speedup on all 7 benchmarks. However, the relative performance of the two parallel simulation kernels is dependent on the size of the ATM network, the number of traffic sources, and the traffic source types used in the simulation. For some benchmarks the best single point performance is provided by the conservative kernel even on a single processor. Unfortunately, the conservative kernel performance is susceptible to small changes in the modeling code and is outperformed by the optimistic kernel on 5 of the 7 benchmarks. The optimistic parallel simulation kernel thus provides most robust performance, but its speedup is limited by the overheads of its implementation, which make it approximately half the speed of the sequential kernel on one processor.
The effect of seance communication on multiprocessing systems
Authors: Mendelson Avi , Gabbay Freddy
Published: July 2002

This paper introduces the seance communication phenomenon and analyzes its effect on a multiprocessing environment. Seance communication is an unnecessary coherency-related activity that is associated with dead cache information. Dead information may reside in the cache for various reasons: task migration, context switches, or working-set changes. Dead information does not have a significant performance impact on a single-processor system; however, it can dominate the performance of multicache environment. In order to evaluate the overhead of seance communication, we develop an analytical model that is based on the fractal behavior of the memory references. So far, all previous works that used the same modeling approach extracted the fractal parameters of a program manually. This paper provides an additional important contribution by demonstrating how these parameters can be automatically extracted from the program trace. Our analysis indicates that Seance communication may severely reduce the overall system performance when using write-update or write-invalidate cache coherency protocols. In addition, we find that the performance of write-update protocols is affected more severely than write-invalidate protocols. The results that are provided by our model are important for better understanding of the coherency-related overhead in multicache systems and for better development of parallel applications and operating systems.
Querying ATSQL databases with temporal logic
Authors: Chomicki Jan , Toman David , Böhlen Michael H.
Published: July 2002

We establish a correspondence between temporal logic and a subset of ATSQL, a temporal extension of SQL-92. In addition, we provide an effective translation from temporal logic to ATSQL that enables a user to write high-level queries which are then evaluated against a space-efficient representation of the database. A reverse translation, also provided in this paper, characterizes the expressive power of a syntactically defined subset of ATSQL queries.
The importance of translucence in mobile computing systems
Authors: Ebling Maria R. , John Bonnie E. , Satyanarayanan M.
Published: July 2002

Mobile computing has been an active area of research for the past decade, but its importance will increase substantially in the decade to come. One problem faced by designers of mobile systems is that of maintaining the illusion of connectivity even when network performance is poor or non-existent. The Coda file system uses its cache to maintain this illusion. Extensive experience with the system suggests that, although users find the functionality provided by the system extremely valuable, new users face an arduous learning curve and even experienced users are sometimes confused by the system's behavior. The fundamental problem is that the lack of a strong network connection causes the system to violate a key property of caching: transparency. To overcome this problem, we have built an interface, called the CodaConsole, that makes caching translucent to users through controlled exposure of cache management internals. The interface exposes critical aspects of caching to support the mobile user while hiding noncritical details to preserve usability. This article presents the design, implementation, and usability evaluation of this interface. The CodaConsole successfully makes caching translucent in the presence of disconnected or weakly connected operation. The most surprising result was that novice Coda users performed almost as well as experienced Coda users.
A counter-example for “a simpler construction for showing the intrinsically exponential complexity of the circularity problem for attribute grammars”
Authors: Dill Jens M.
Published: July 2002

Jazayeri [
J. ACM 28
, 4 (Oct. 1981), 715-720] proposes a simpler construction for use in the proof by Jazayeri et al. [
Commun. ACM 18
, 12 (Dec. 1975), 697-706] that the circularity problem for attribute grammars has inherent exponential time complexity. The simplification introduces a flaw that invalidates the proof. The flaw can be corrected, at the cost of eliminating some of the simplification claimed for the new construction.
The performance of a precedence-based queuing discipline
Authors: Tsitsiklis John N. , Papadimitriou Christos H. , Humblet Pierre
Published: July 2002

A queuing system with infinitely many servers, and with the following queuing discipline is considered: For any two jobs
i
and
j
in the system, such that
i
arrived later than
j
, there is a fixed probability
p
that
i
will have to wait for
j
's execution to terminate before
i
starts executing. This queuing system is a very simple model for database concurrency control via “static” locking, as well as of parallel execution of programs consisting of several interdependent processes. The problem of determining the maximum arrival rate (as a function of
p
) that can be sustained before this system becomes unstable is studied. It is shown that this rate is inversely proportional to
p
, and close upper and lower bounds on the constant for the case of deterministic departures are found. The result suggests that the degree of multiprogramming of multiuser databases, or the level of parallelism of concurrent programs, is inversely proportional to the probability of conflict, and that the constant is small and known within a factor of 2. The technique used involves the computation of certain asymptotic parameters of a random infinite directed acyclic graph (dag) that seem of interest by themselves.
An adaptive mesh-moving and local refinement method for time-dependent partial differential equations
Authors: Arney David C. , Flaherty Joseph E.
Published: July 2002

We discuss mesh-moving, static mesh-regeneration, and local mesh-refinement algorithms that can be used with a finite difference or finite element scheme to solve initial-boundary value problems for vector systems of time-dependent partial differential equations in two space dimensions and time. A coarse base mesh of quadrilateral cells is moved by an algebraic mesh-movement function so as to follow and isolate spatially distinct phenomena. The local mesh-refinement method recursively divides the time step and spatial cells of the moving base mesh in regions where error indicators are high until a prescribed tolerance is satisfied. The static mesh-regeneration procedure is used to create a new base mesh when the existing one becomes too distorted. The adaptive methods have been combined with a MacCormack finite difference scheme for hyperbolic systems and an error indicator based upon estimates of the local discretization error obtained by Richardson extrapolation. Results are presented for several computational examples.
Astrobiology: Exploring the Origins, Evolution, and Distribution of Life in the Universe
Authors: Marais D. J. Des , Walter M. R.
Published: July 2002

▪ Abstract  The search for the origins of life and its presence beyond Earth is strengthened by new technology and by evidence that life tolerates extreme conditions and that planets are widespread. Astrobiologists learn how planets develop and maintain habitable conditions. They combine biological and information sciences to decipher the origins of life. They examine how biota, particularly microorganisms, evolve, at scales from the molecular to the biosphere level, including interactions with long-term planetary changes. Astrobiologists learn how to recognize the morphological, chemical, and spectroscopic signatures of life in order to explore both extraterrestrial samples and electromagnetic spectra reflected from extrasolar planets.
J. S. Kennedy (1912–1993): A Clear Thinker in Behavior's Confused World
Authors: Brady John
Published: July 2002

This is an account of the scientific life of John Stodart Kennedy, Fellow of the Royal Society; Emeritus Professor of Animal Behaviour at Imperial College, London; the holder of numerous scientific honors; and known to us all as JSK. He was not at heart an entomologist; his principal interest was in the integration of animal behavior, but he pursued that interest through a lifetime's study of locusts, aphids, and moths, especially in the context of how they integrated their flight behavior. Two features marked his science: an obsession with accurate, objective quantification of animals' behavioral responses through experimentation and a ruthless demolition of anthropomorphic analyses of behavioral causes. This biography is both a history of his scientific work and a tribute to a hugely admired colleague, research leader, and friend of some 30 years. The details of Kennedy's life were provided in part by his family, in part by the autobiographical notes he wrote for the Royal Society, and in part by his surviving colleagues from those early years; the last three decades are based on the author's personal knowledge and observation.
Endovascular Treatment of Abdominal Aortic Aneurysms
Authors: Treiman Gerald S. , Bernhard, MD Victor M.
Published: July 2002

Abdominal aortic aneurysms (AAA) may now be treated by endovascular placement of an arterial graft. These grafts are inserted through the femoral artery and then secured to the aorta above and below the aneurysm. The procedure reduces the risk of many perioperative complications and reduces hospital costs and length of stay. Several FDA-approved clinical trials are currently in progress with a variety of different devices. None is available for general use at this time. Overall, more than 800 grafts have now been placed, with a primary success rate of greater than 80%. Several complications have been reported, but the incidence of complications has generally decreased as proficiency has improved. The most troublesome problem has been leak of blood around the graft with continued risk of aneurysm rupture; therefore, follow-up CT scans and clinical examinations are mandatory to allow for appropriate treatment. Future modifications of current devices and techniques for delivery can be expected to reduce the incidence of currently identified problems. Endovascular grafting for AAA offers important potential advantages over conventional repair and may become increasingly important in the management of patients who have an abdominal aortic aneurysm.
The Biology of Cystitis: Host and Bacterial Factors
Authors: Sussman, PhD M. , Gally, PhD D. L.
Published: July 2002

Cystitis is caused by a relatively small number of bacterial species. To colonize and grow in the urinary tract, these organisms have developed and acquired special properties (virulence factors) that allow them to overcome the defences of the urinary tract, particularly clearance by urine flow. These virulence factors are unlikely to be required during transmission from host to host, and sometimes their constitutive expression may actually be disadvantageous. Such factors are therefore regulated by the environment and in a coordinate manner to ensure their most appropriate expression for the conditions encountered. This review focuses on the biology of the urinary tract and the bacterial properties necessary to cause cystitis. The regulation of virulence factors at the different stages of the infection is considered, and a general model for the pathogenesis of urinary tract infection is proposed.
Thalidomide: Emerging Role in Cancer Medicine
Authors: Richardson Paul , Hideshima Teru , Anderson Kenneth
Published: July 2002

▪ Abstract  Thalidomide—removed from widespread clinical use by 1962 because of severe teratogenicity—has antiangiogenic and immunomodulatory effects, including the inhibition of tumor necrosis alpha factor. It has now returned to practice as an effective oral agent in the management of various disease states including erythema nodosum leprosum, for which it was approved by the U.S. Food and Drug Administration in 1998, and more recently certain malignancies, including multiple myeloma. Although thalidomide's mechanism of action remains incompletely understood, considerable insight has been generated by extensive preclinical studies in multiple myeloma. Moreover, clinical trials have confirmed benefit in relapsed disease, and the role of thalidomide in treating newly diagnosed patients is currently under study. Its use in other tumors is under evaluation, with promise in renal cell carcinoma, prostate cancer, glioma, and Kaposi's sarcoma. Activity has also been demonstrated in chronic graft-versus-host disease and in symptom relief as part of palliative care.
Contributions of Genome Sequencing to Understanding the Biology ofHelicobacter pylori
Authors: Ge Zhongming , Taylor Diane E.
Published: July 2002

▪ Abstract  About half of the world's population carries Helicobacter pylori, a gram-negative, spiral bacterium that colonizes the human stomach. The link between H. pylori and, ulceration as well as its association with the development of both gastric cancer and mucosa-associated lymphoid tissue lymphoma in humans is a serious public health concern. The publication of the genome sequences of two stains of H. pylori gives rise to direct evidence on the genetic diversity reported previously with respect to gene organization and nucleotide variability from strain to strain. The genome size of H. pylori strain 26695 is 1,6697,867 bp and is 1,643,831 bp for strain J99. Approximately 89% of the predicted open reading frames are common to both of the strains, confirming H. pylori as a single species. A region containing ∼45% of H. pylori strain-specific open reading frames, termed the plasticity zone, is present on the chromosomes, verifying that some strain variability exists. Frequent alteration of nucleotides in the third position of the triplet codons and various copies of insertion elements on the individual chromosomes appear to contribute to distinct polymorphic fingerprints among strains analyzed by restriction fragment length polymorphisms, random amplified polymorphic DNA method, and repetitive element–polymerase chain reaction. Disordered chromosomal locations of some genes seen by pulsed-field gel electrophoresis are likely caused by rearrangement or inversion of certain segments in the genomes. Cloning and functional characterization of the genes involved in acidic survival, vacuolating toxin, cag-pathogenicity island, motility, attachment to epithelial cells, natural transformation, and the biosynthesis of lipopolysaccharides have considerably increased our understanding of the molecular genetic basis for the pathogenesis of H. pylori. The homopolymeric nucleotide tracts and dinucleotide repeats, which potentially regulate the on- and off-status of the target genes by the strand-slipped mispairing mechanism, are often found in the genes encoding the outer-membrane proteins, in enzymes for lipopolysaccharide synthesis, and within DNA modification/restriction systems. Therefore, these genes may be involved in the H. pylori–host interaction.
THE PHARMACOLOGY AND TOXICOLOGY OF POLYPHENOLIC-GLUTATHIONE CONJUGATES
Authors: Monks Terrence J. , Lau Serrine S.
Published: July 2002

▪ Abstract  Polyphenolic-glutathione (GSH) conjugates and their metabolites retain the electrophilic and redox properties of the parent polyphenol. Indeed, the reactivity of the thioether metabolites frequently exceeds that of the parent polyphenol. Although the active transport of polyphenolic-GSH conjugates out of the cell in which they are formed will limit their potential toxicity to those cells, once within the circulation they can be transported to tissues that are capable of accumulating these metabolites. There are interesting physiological similarities between the organs that are known to be susceptible to polyphenolic-GSH conjugate-mediated toxicity. In addition, the frequent localization of γ-glutamyl transpeptidase to cells separating the circulation from a second fluid-filled compartment coincides with tissues that are susceptible either to polyphenolic-GSH conjugate-induced toxicity or to quinone and reactive oxygen species–induced toxicity. Polyphenolic-GSH conjugates therefore contribute to the nephrotoxicity, nephrocarcinogenicity, and neurotoxicity of a variety of polyphenols.
Public Health Genetics: An Emerging Interdisciplinary Field for the Post-Genomic Era
Authors: Omenn Gilbert S.
Published: July 2002

▪ Abstract  Public health genetics is an exciting interdisciplinary area that brings all the public health sciences to bear on the emerging challenge of interpreting the medical and public health significance of genetic variation within populations. Sequencing of the human genome will generate an avalanche of genetic information to be linked with information about microbial, chemical, and physical exposures; nutrition, metabolism, lifestyle behaviors, and medications. The public health genetics mini-symposium in this volume includes articles dealing with educational innovations, host-pathogen interactions in infectious diseases, nutrition/genetic interactions in cancers, and population screening for hemochromatosis. Additional topics addressed here are ecogenetics and risk assessment, the genetics of unhealthful behaviors, and ethical and policy issues. Finally, a set of principles for community-based health research in populations is presented as a public health-oriented counterpart to the principle of autonomy and the practice of informed consent that have become key elements of ethics in medical care and medical research with individuals.
Henri Poincaré, Marcel Duchamp and Innovation in Science and Art
Authors: Holton Gerald
Published: July 2002

In the early years of the twentieth century, the striking scientific developments of the period included a great increase in popular and professional attention to non-Euclidean geometry. One of the leading scholars of the subject was Henri Poincaré, who was also a widely read theorist of the scientific discovery process, keenly concerned with the role of the intuition and the subconscious. His writings, and those of his interpreters, could well have increased the appeal of four-dimensional geometry for artists already attracted to the possibilities presented by these concepts. The working notes of one such artist, Marcel Duchamp, record directly his debt to ideas linked to Poincaré—an example of the interaction of greatly different parts of the wider culture.
An Adaptive Bayesian Pruning for Neural Networks in a Non-Stationary Environment
Authors: Sum John , Leung Chi-sing , Young Gilbert H. , Chan Lai-wan , Kan Wing-kay
Published: July 2002

Pruning a neural network to a reasonable smaller size, and if possible to give a better generalization, has long been investigated. Conventionally the common technique of pruning is based on considering error sensitivity measure, and the nature of the problem being solved is usually stationary. In this article, we present an adaptive pruning algorithm for use in a nonstationary environment. The idea relies on the use of the extended Kalman filter (EKF) training method. Since EKF is a recursive Bayesian algorithm, we define a weight-importance measure in term of the sensitivity of a posteriori probability. Making use of this new measure and the adaptive nature of EKF, we devise an adaptive pruning algorithm called adaptive Bayesian pruning. Simulation results indicate that in a noisy nonstationary environment, the proposed pruning algorithm is able to remove network redundancy adaptively and yet preserve the same generalization ability.
Integration of Functional and Environmental Performance Design Decisions: A Mechanical Component Case Study
Authors: Bauer Diana , Sheng Paul
Published: July 2002

Product design‐for‐environment (DfE) has traditionally relied on life‐cycle assessment (LCA) as a primary means of assessing environmental performance. To date, LCA has focused on static inventory and impacts of material streams during the stages of resource extraction, component manufacture, product use, and end of life at a high level of aggregation. Improvement analysis, though theoretically an important stage of LCA, is practically very challenging to implement using LCA alone. One reason for this is that the focus on detailed characterization of material streams does not facilitate a development of an understanding of the mechanistic relationship between design intent and material, manufacturing, and use‐phase potential impacts. As the product development community transitions from sequential design to more streamlined concurrent design, interactive design tools are needed as a supplement to assessment tools in order to facilitate tradeoffs among environmental and other factors. This article presents an environmental analysis approach based on detailed process modeling which evaluates components from a functional design point of view. From a manufacturer's perspective, local potential effects in aggregate are often as important as global potential impacts. Furthermore, impacts often relate to explicit trade‐offs between different life‐cycle stages, such as production and use. In this article, the influence of functional design and manufacturing specifications (surface tolerance and finish) on localized potential impacts is illustrated through two different mechanical component (steel roller bearing and rotating shaft) case studies. Detailed analytical tools are key in enabling optimization and trade‐offs by designers and process planners. The functional modeling approach is an important complement to LCA in providing a well‐defined view of environmental performance.
LE POÈME ACROSTICHE SUR EXODE XX 1-5 DANS LE TARGUM FRAGMENTAIRE (MS G)
Authors: Himbaza Innocent
Published: July 2002

Le Targum fragmentaire G (Ms G) qui contient le début d'Exode xx a fait récemment l'objet d'une publication de P. Grelot dans la Revue des études juives 159 (2000). Cependant cette publication suscite des objections sur la structure du poème et sur le rôle des textes en prose que nous avons à l'intérieur de ce poème. Cette article entend présenter ce texte autrement en se basant sur la comparaison avec les autres textes targumiques.
BEHAVIOURAL STRATEGIES, TESTIS SIZE, AND REPRODUCTIVE SUCCESS IN TWO CAVIOMORPH RODENTS WITH DIFFERENT MATING SYSTEMS
Authors: Sachser Norbert , Schwarz-Weig Esther , Keil Anja , Epplen Jorg
Published: July 2002

We summarize our studies on the social and mating systems of Cavia aperea and Galea musteloides , two closely related South-American rodents. In Cavia an extremely high incompatibility exists among adult males. As a consequence, only a single male can be kept together with several females even in richly structured enclosures of 20 m2. From this, a polygynous mating system emerges. In contrast, under similar housing conditions male Galea are much more tolerant and large groups can be established consisting of several adult males and several adult females. The mating system of Galea is promiscuous because of the female's soliciting behaviour when receptive that makes it impossible for a single male to monopolize her. The diverging mating systems correspond well with functional variations in testis size and sexual dimorphism: the polygynous Cavia show low testis masses (weight of both testes = 0.58% of body weight) and body weights are 11% higher in males than in nonpregnant females. The promiscuous Galea have extremely high relative testis masses (1.86% of body weight) and non-pregnant females are 15% heavier than males. In the latter species promiscuous mating results in a high percentage of multiple paternities (> 80% in groups of 4 males and 6-7 females) as revealed by multi-locus DNA fingerprinting. Nevertheless dominant males achieve a significantly higher reproductive success than subordinates. The high frequency of overt aggression directed from dominant to subordinate males, therefore, may be a mechanism to lower the fertilizing capacity of the lower ranking males. Concerning the females' reproductive success we demonstrated in a mating experiment that Galea which were paired with four males and became pregnant, weaned significantly more offspring than females which were paired with a single male. Thus, for the first time a reproductive benefit from promiscuous mating is shown for a female mammal. Field studies in the natural habitats of Cavia aperea and Galea musteloides are now performed to elucidate whether the differences in social and mating systems can be related to differences in ecological conditions.
THE SPEAR LOBSTER, LINUPARUS SOMNIOSUS BERRY & GEORGE, 1972 (DECAPODA, PALINURIDAE) IN INDONESIA
Authors: Wowor Daisy
Published: July 2002

ABSTRACT The spear lobster, Linuparus somniosus Berry & George, 1972 (Palinuridae), is here reported for the first time from relatively shallow waters off southern Java, Indonesia. This is only the second time that the species is recorded from Southeast Asia. Sexual dimorphism in the pereiopods is reported: those of males being more robust than those of females. Several other taxonomic characters are also discussed. Notes on the local fisheries for this species are provided.
Linuparus somniosus Berry & George, 1972 (Palinuridae) est signale pour la premiere fois d'eaux relativement peu profondes au sud de Java (Indonesie); c'est la seconde fois seulement que l'espece est signalee du Sud-est de l'Asie. Le dimorphisme sexuel des pereiopodes est mentionne, ceux du male etant plus robustes que ceux de la femelle. D'autres caracteres taxonomiques sont aussi discutes. Des notes sur les pecheries locales de cette espece sont fournies.
Population growth of two aphelenchid nematodes with six different fungi as a food source
Authors: Ikonen Eeva
Published: July 2002

Differences in population growth patterns of two nematode species, Aphelenchoides bicaudatus and Aphelenchus avenae, were observed on food sources of agar plate cultures of six fungi, Cladosporium cladosporioides, C. herbarum, Fusarium chlamydosporum, Penicillium simplicissimum and P.restrictum strains I and II. The population, measured as biomass or individuals cm-2, of A. bicaudatus was bigger than that of A. avenae after 20-23 days at the end of the experiment with most of the fungi. However, the population growth of A. avenae on P.restrictum (I) was faster after the first 7 days than that of A. bicaudatus. On cultures of F. chlamydosporum and C. herbarum, the population growth of both nematodes was greater than on the other fungi. C. cladosporioides did not support the reproduction of either nematode.
The effect of dry heating of synthetic 2-line and 6-line ferrihydrite: II. Surface area, porosity and fractal dimension
Authors: Weidler P. G. , Stanjek H.
Published: July 2002

Nitrogen adsorption isotherms were measured on synthetic 2-line and 6-line ferrihydrites heated to 400 K, 500 K, and 600 K under dry conditions for different times ranging from 4 to 3000 h. Evaluation of specific surface area, microporosity and fractal dimension revealed that 2-line and 6-line ferrihydrites are highly microporous powders consisting of aggregates with corrugated interior and exterior surfaces. Furthermore, the surfaces of the single particles forming the aggregates have a smaller fractal dimension, i.e. a smoother appearance, than those of the entire aggregate. The diffusion of water lost during the heating process is influenced by the size of the micropores. The initial stage of the dehydration of the ferrihydrites can be described as similar to the process of Ostwald ripening.
Chemical zoning of muscovite from the Ervedosa granite, northern Portugal
Authors: Gomes M. E. P. , Neiva A. M. R.
Published: July 2002

The tin-bearing muscovite granite from Ervedosa contains unzoned primary muscovite. This Hercynian S-type granite was hydrothermally altered at the stanniferous quartz vein walls and contains three types of muscovite: (1) very small unzoned muscovite replacing albite; (2) small unzoned hydrothermal muscovite replacing K-feldspar and quartz; and (3) zoned subhedral muscovite.

In the zoned muscovite, the core has a composition similar to that of magmatic muscovite from the unaltered granite, while the rim has a composition similar to that of hydrothermal muscovite replacing K-feldspar and quartz in the altered granite. The rim corresponds to a late overgrowth richer in the celadonitic component than the core. Infiltrated mineralizing fluids reacted with biotite and K-feldspar of the unaltered granite. We interpret the rim of muscovite to have precipitated from these solutions.
Computer simulation of aqueous pore fluids in 2:1 clay minerals
Authors: Skipper N. T.
Published: July 2002

Monte Carlo and molecular dynamics computer simulations are now able to provide detailed information concerning the structure, dynamics, and thermodynamics of pore fluids in 2:1 clays. This article will discuss interparticle interaction potentials currently available for atomistic simulations of clay-water systems, and will describe how computational techniques can be applied to modelling of clay systems. Some recent simulation studies of 2:1 clay hydration will then be reviewed. Comparison with experimental data promotes confidence in the molecular models and simulation techniques, and points to exciting future prospects.
A gene therapy approach for treating T-cell–mediated autoimmune diseases
Authors: Chen Chiann-Chyi , Rivera Amariliz , Ron Naomi , Dougherty Joseph P. , Ron Yacov
Published: July 2002

Experimental autoimmune encephalomyelitis (EAE) is a demyelinating disease of the central nervous system (CNS) that serves as a model for multiple sclerosis (MS) in humans. In mice, EAE is mediated by Th1 type CD4+ T cells specific for various myelin proteins which migrate from the periphery to the CNS. Removal or blocking of CD4+ cells before or shortly after disease induction was shown to prevent disease onset and/or disease progression but also results in general immune suppression. Most treatment regimens for autoimmune diseases currently rely on general suppression of the T-cell compartment most commonly by steroids. In this paper, an experimental, gene therapy-based model is presented in which susceptible mice are made resistant to EAE induction by specifically down-regulating an autoreactive T-cell population. By using a retroviral gene transfer protocol, normal B cells were genetically modified to constitutively express the SJL-specific proteolipid (PLP) encephalitogenic determinant and then adoptively transferred into syngeneic hosts. To ensure appropriate presentation of the exogenous encephalitogenic peptide in association with MHC class II, the encephalitogenic sequence was fused to a lysosomal targeting sequence. Adoptive transfer of syngeneic B cells expressing the PLP encephalitogenic determinant into normal, naive, genetically susceptible mice induced PLP-specific unresponsiveness and completely protected the majority (62% and 83% using an intermediate and a high titer retroviral vector, respectively) of the animals from EAE induction. The remaining animals had a delayed disease onset and/or lower disease severity. All protected mice expressed the exogenous gene in the spleen as detected by reverse transcriptase-polymerase chain reaction.
Age-related increase of frequency of a new, phenotypically distinct subpopulation of human peripheral blood T cells expressing lowered levels of CD4
Authors: Bryl Ewa , Gazda Magdalena , Foerster Jerzy , Witkowski Jacek M.
Published: July 2002

Aging is associated with modifications of T-cell phenotype and function, leading to impaired activation in response to both new and recall antigens. It is not known if T-cell activation results in elimination of a number of the CD4 molecules from the cell surface, as is the case with CD3/T-cell receptor complexes, or how aging influences the process. The T cells of young and elderly donors with reduced expression of CD4 were examined to see whether these cells exhibit other phenotypic features suggesting their active state. It was found that T lymphocytes expressing CD4 can be divided into 2 semidiscrete subpopulations: the major (CD4+) population, in which the level of expression of CD4 is constant and high, and a minor population (CD4lo), in which the expression of CD4 can be up to an order of magnitude lower than on the CD4+ cells. The proportion of CD4locells is age dependent and highly variable in the apparently healthy human population, with the expression of CD4 ranging from around 10% of all peripheral blood lymphocytes in the young to more than 30% in the elderly. Lowered expression of CD4 is correlated with a reduced expression of CD3, as well as with a decreased amount of CD28 and CD95Fas. Activation of CD4lo cells is suggested by their expression of CD25 and increased amounts of HLA-DR. Phenotypic characteristics of the CD4lo T-cell subpopulation suggest that it might be formed by (perhaps chronically) activated, temporarily apoptosis-resistant cells, possibly accumulating in the elderly.
US Elections Will Determine the Fate of Extended ACA Subsidies
Authors: O’Mahen Patrick N. , Petersen Laura A.
Published: November 2024

This Viewpoint discusses the implications that the 2024 presidential election may have on the status of the temporary expansions to the Affordable Care Act’s Advanced Premium Tax Credits.
Social Isolation and Mortality in Adults With Chronic Obstructive Pulmonary Disease
Authors: Suen Angela O. , Iyer Anand S. , Cenzer Irena , Singer Jonathan P. , Smith Alexander , Sudore Rebecca L. , Kotwal Ashwin
Published: November 2024

This cohort study uses national data to investigate the association between social isolation and all-cause mortality in adults with chronic obstructive pulmonary disease.
Lung Cancer Screening Communication in the US, 2022
Authors: Sonawane Kalyani , Garg Ashvita , Toll Benjamin A. , Deshmukh Ashish A. , Silvestri Gerard A.
Published: November 2024

This cross-sectional study examines lung cancer screening communication between US clinicians and patients by smoking status and demographic, socioeconomic, and clinical characteristics.
Suicide Deaths Among Adolescent and Young Adult Patients With Cancer
Authors: Matsuo Koji , Duval Christina J. , Nanton Briana A. , Yao Jennifer A. , Yu Erin , Pino Christian , Wright Jason D.
Published: November 2024

This cohort study evaluates differences in suicide death rates across age groups of adolescent and young adult patients with cancer over time in the US.
Day Care Attendance and Risk of Type 1 Diabetes
Authors: Tall Susanna , Virtanen Suvi M. , Knip Mikael
Published: November 2024

Importance

A meta-analysis published in 2001 suggested that exposure to infections measured by day care attendance may be important in the pathogenesis of type 1 diabetes. Several new studies on the topic have since been published.

Objective

To investigate the association between day care attendance and risk of type 1 diabetes and to include all available literature up to March 10, 2024.

Data Sources

Data from PubMed and Web of Science were used and supplemented by bibliographies of the retrieved articles and searched for studies assessing the association between day care attendance and risk of type 1 diabetes.

Study Selection

Studies that reported a measure of association between day care attendance and risk of type 1 diabetes were included.

Data Extraction and Synthesis

Details, including exposure and outcome assessment and adjustment for confounders, were extracted from the included studies. The multivariable association with the highest number of covariates, lowest number of covariates, and unadjusted estimates and corresponding 95% CIs were extracted. DerSimonian and Laird random-effects meta-analyses were performed and yielded conservative confidence intervals around relative risks.

Main Outcomes and Measures

The principal association measure was day care attendance vs no day care attendance and risk of type 1 diabetes.

Results

Seventeen articles including 22 observational studies of 100 575 participants were included in the meta-analysis. Among the participants, 3693 had type 1 diabetes and 96 882 were controls. An inverse association between day care attendance and risk of type 1 diabetes was found (combined odds ratio, 0.68; 95% CI, 0.58-0.79; P < .001; adjusted for all available confounders). When the 3 cohort studies included were analyzed separately, the risk of type 1 diabetes was 15% lower in the group attending day care; however, the difference was not statistically significant (odds ratio, 0.85; 95% CI, 0.59-1.12; P = .37).

Conclusions and Relevance

These results demonstrated that day care attendance appears to be associated with a reduced risk of type 1 diabetes. Increased contacts with microbes in children attending day care compared with children who do not attend day care may explain these findings. However, further prospective cohort studies are needed to confirm the proposed association.
Heat application in live cell imaging
Authors: Sistemich Linda , Ebbinghaus Simon
Published: November 2024

Thermal heating of biological samples allows to reversibly manipulate cellular processes with high temporal and spatial resolution. Manifold heating techniques in combination with live‐cell imaging were developed, commonly tailored to customized applications. They include Peltier elements and microfluidics for homogenous sample heating as well as infrared lasers and radiation absorption by nanostructures for spot heating. A prerequisite of all techniques is that the induced temperature changes are measured precisely which can be the main challenge considering subcellular structures or multicellular organisms as target regions. This article discusses heating and temperature sensing techniques for live‐cell imaging, leading to future applications in cell biology.