bluuebunny/crossref_metadata_2025 huggingface dataset:
Subordination criteria for starlikeness and convexity
Authors: Aghalary Rasoul , Jahangiri Jay M.
Published: June 2003

For functions p analytic in the open unit disc U = {z : |z| < 1} with the normalization p(0) = 1, we consider the families 𝒫[A, −1], −1 < A ≤ 1, consisting of p such that p(z) is subordinate to (1 + Az)/(1 − z) in U and 𝒫(1, b), b > 0,
consisting of p, which have the disc formulation |p − 1| < b in U. We then introduce subordination criteria for the choice of
p(z) = zf′(z)/f(z), where f is analytic in U and normalized by f(0) = f′(0) − 1 = 0. We also obtain starlikeness and convexity
conditions for such functions f and consequently extend and, in
some cases, improve the corresponding previously known results.
Invariant subspaces for polynomially compact almost superdiagonal operators on l(pi)
Authors: Grainger Arthur D.
Published: June 2003

It is shown that almost superdiagonal, polynomially compact operators on the sequence space l(pi) have nontrivial, closed invariant subspaces if the nonlocally convex linear topology τ(pi) is locally bounded.
On an inequality of Diananda
Authors: Gao Peng
Published: June 2003

We consider certain refinements of the arithmetic and geometric
means. The results generalize an inequality of P. Diananda.
A semilinear transport equation with delays
Authors: Dyson Janet , Villella-Bressan Rosanna , Webb Glenn F.
Published: June 2003

An analysis is provided for a model of the blood production system
based on a cell population structured by a continuous variable corresponding to the maturity of individual cells. Cell maturity is viewed as an indicator of increasing
morphological development, ranging from the most primitive stem cells to the most mature differentiated cells. The analysis distinguishes two fundamental behaviors based on the nature of the initial state of the system: the first is a normal
production of cells, when the initial state contains a sufficient supply of the least mature cells; the second is an abnormal production, when the initial state is deficient in the population of the least mature cells.
Gaussian quadrature rules and A‐stability of Galerkin schemes for ODE
Authors: Bensebah Ali , Dubeau François , Gélinas Jacques
Published: June 2003

The A‐stability properties of continuous and discontinuous Galerkin methods for solving ordinary differential equations (ODEs) are established using properties of Legendre polynomials and Gaussian quadrature rules. The influence on the A‐stability of the numerical integration using Gaussian quadrature rules involving a parameter is analyzed.
ECOLOGY, ECONOMY AND REDEMPTION AS DYNAMIC: THE CONTRIBUTIONS OF JANE JACOBS AND BERNARD LONERGAN
Authors: Byrne Patrick
Published: June 2003

Bernard Lonergan, S.J. and Jane Jacobs have devoted much of their intellectual careers to thinking out the dynamic natural-human environment. Lonergan and Jacobs worked in very different lines of research - systematic theology and urban economics, respectively. Despite predictable differences in their thought, there are also remarkable commonalities in their analyses. Both thinkers have argued that the same dynamic principles that govern the functioning of natural ecologies are also to be found when human social and economic systems function well, but are absent when human systems go wrong. Both have argued that the violation of principles that pertain to natural ecologies is destructive not only of the natural environment, but of communal and economic well-being as well. Jacobs came to prominence with the 1961 publication of her classic, The Death and Life of Great American Cities. She has since gone on to extend her analysis to the unique characteristics of urban economics in several books and articles. In her most recent book The Nature of Economies (2000), Jacobs draws the results of her previous work on urban economic patterns into a synthesis with recent insights into biological systems. She argues that exactly the same principles (or "processes" as she prefers to call them) that sustain vital, evolving natural ecologies also underpin robust and dynamic economies. Where Jacobs's work gives a richly detailed account of the processes shared alike by natural and human systems, Lonergan developed a parallel, integral account of natural processes, human social and economic organization, and the "economy of salvation." In his classic work, Insight, Lonergan argues that the dynamics of human innovations and self-correction correspond in striking ways to the emergence, growth, development, and decline in the natural order. Unlike natural ecologies, however, the possibilities of genuine social and economic development are distorted, Lonergan argues, by the forces of "bias." In his role of theologian, Lonergan goes on to explore how divine grace heals the distorted dynamics of natural and human ecologies.
THE ECOLOGICAL COMMUNITY AND THE NARRATIVE OF CREATION
Authors: Scott Dane
Published: June 2003

The ideal of an ecological community uniting humans to the earth is an important normative ideal in environmental ethics. In this paper I will briefly look at one of the more popular stories that provides the philosophical underpinnings for this ideal. This is the story told by Baird Callicott, through his interpretation of Leopold's land ethic. In the critical portion of this essay, I point to problems with this account. The goal is not to prove this story false, but to indicate its inadequacies. In the constructive portion, I will discuss the philosophical underpinnings for an alternative story for realizing the hoped-for ecological community from the perspective of the Judeo-Christian tradition. This alternative story relies on an account of moral agency found in the narrative ethics of Alasdair MacIntrye. But it also reclaims neglected insights from Josiah Royce. In this account a community narrative is required that formed through a dialogue between the scientifically informed idea of the ecological community and the Judeo-Christian narrative of creation.
CONTROLLING CONSUMPTION: A ROLE FOR CHRISTIANITY?
Authors: Laurendeau Normand
Published: June 2003

Economic globalization suggests that sustainability will be threatened more by consumption than by population. While technology should prove helpful, our major environmental threat appears to be the rising demand for products and services. Hence, in the long run, sustainability requires human actions to prevent systemic harm rather than technical solutions that might merely reduce specific harm to the environment. In general, Christianity has dealt only weakly with the ethics of sustainability, and especially with the continuing consumption of global resources by affluent nations. In this paper, I analyze the potential for a new Christian focus on the satisfaction, satiation, and sublimation of material needs and desires. Important queries considered by the analysis include the following: (1) Does technology create metaphysical desire? (2) Is consumption thus inherently addictive? (3) Can religion help control this addiction? Employing dispositive and operative aspects of responsibility theory, I argue that a convivial future requires that we give prime attention to the demands of both distributive justice and environmental sustainability. On this basis, Christianity ought to place greater emphasis on equity issues associated with conservation, resource reduction, and renewable energy. Unfortunately, responsibility theory is inherently responsive rather than proactive, and thus probably more appropriate for avoiding a worse rather than creating a better future. My suggestion is that an eschatological approach to sustainability may offer new hope for the control of rampant materialism. In particular, Christianity must take seriously the need for an eventual re-integration between technology and religion. This re-integration should focus primarily on respecting physical limits, especially in an uncertain world characterized by a rising rich-poor gap. Such respect defines a new kenotic technology, which leads naturally to an allied kenotic consumption. As a result, Christian responsibility suggests that we can best imitate Christ by moderating profligate life-styles. From this perspective, the Church's prime responsibility in an environmental age is to model much better than it currently does the re-conversion of modern material growth to post-modern spiritual growth.
Technical Description of RODS: A Real-time Public Health Surveillance System
Authors: Tsui Fu-Chiang , Espino Jessi , Dato Virginia M. , Gesteland Per H. , Hutman Judith , Wagner Michael M.
Published: June 2003

This report describes the design and implementation of the Real-time Outbreak and Disease Surveillance (RODS) system, a computer-based public health surveillance system for early detection of disease outbreaks. Hospitals send RODS data from clinical encounters over virtual private networks and leased lines using the Health Level 7 (HL7) message protocol. The data are sent in real time. RODS automatically classifies the registration chief complaint from the visit into one of seven syndrome categories using Bayesian classifiers. It stores the data in a relational database, aggregates the data for analysis using data warehousing techniques, applies univariate and multivariate statistical detection algorithms to the data, and alerts users of when the algorithms identify anomalous patterns in the syndrome counts. RODS also has a Web-based user interface that supports temporal and spatial analyses. RODS processes sales of over-the-counter health care products in a similar manner but receives such data in batch mode on a daily basis. RODS was used during the 2002 Winter Olympics and currently operates in two states—Pennsylvania and Utah. It has been and continues to be a resource for implementing, evaluating, and applying new methods of public health surveillance.
Life, death and membrane bilayers
Authors: Hulbert A. J.
Published: June 2003

Membrane bilayers are essential elements of life, and the synthesis of the hydrocarbons that make up membrane bilayers may have preceded the appearance of life on Earth. Membrane-associated processes are significant components of metabolism, and the acyl composition of membrane bilayers is associated with metabolic activity in a predictable manner. This has resulted in the `membrane pacemaker' theory of metabolism, which proposes that the relative balance between monounsaturated and long-chain polyunsaturated acyl chains in membrane bilayers is a fundamental determinant of metabolic rate of a species. The omega-3 polyunsaturated docosahexaenoate is an especially important component of membranes in this regard. Whilst it is suggested that the physical properties of membrane polyunsaturates are important with respect to their influence on metabolic rate, it is their chemistry that is important in aging. Membrane acyl composition is related to maximum lifespan in mammals and birds,probably via their role in lipid peroxidation. Calorie restriction modifies acyl composition of membrane bilayers and is associated with decreased membrane lipid peroxidation and lifespan extension. The membrane pacemaker theory of metabolism has given birth to the membrane pacemaker hypothesis of aging, which will require further investigation.
Heat-shock response and temperature resistance in the deep-sea vent shrimp Rimicaris exoculata
Authors: Ravaux Juliette , Gaill Françoise , Bris Nadine Le , Sarradin Pierre-Marie , Jollivet Didier , Shillito Bruce
Published: June 2003

The shrimp Rimicaris exoculata swarms around hydrothermal black smoker chimneys at most vent sites along the Mid-Atlantic Ridge. This species maintains close proximity to the hydrothermal fluid, where temperatures can reach 350°C and steep thermal and chemical gradients are expected. We performed in vivo experiments in pressurized aquaria to determine the upper thermal limit [critical thermal maximum (CTmax)] of R. exoculata and to investigate some characteristics of the shrimp stress response to heat exposure. These experiments showed that the shrimp does not tolerate sustained exposure to temperatures in the 33-37°C range(CTmax). A heat-inducible stress protein belonging to the hsp70 family was identified in R. exoculata, and its synthesis threshold induction temperature is below 25°C. The R. exoculataoptimal thermal habitat may thus be restricted to values lower than previously expected (<25°C).
The role of eukaryotic initiation factor 2α during the metabolic depression associated with estivation
Authors: Pakay Julian L. , Hobbs Andrew A. , Kimball Scot R. , Guppy Michael
Published: June 2003

We have investigated the role of eukaryotic initiation factor 2α(eIF2α) in two estivating organisms previously shown to downregulate protein synthesis during metabolic depression, the land snail Helix aspersa Müller and the desert frog Neobatrachus sutor Main 1957. We have developed a method using a single antibody (which binds specifically to the phosphorylated, conserved phosphorylation region) by which the total levels of eIF2α and the ratio of phosphorylated eIF2α[eIF2α(P)] to total (phosphorylated and unphosphorylated) eIF2αcan be determined. In H. aspersa, we have shown that the level of eIF2α mRNA expression is unchanged between the awake and estivating states. The amount of total eIF2α is the same in the estivating and awake states, and eIF2α(P) is undetectable and must represent ≤10% of total eIF2α in both states. Conversely, in N. sutor during estivation, the level of total eIF2α increases approximately 1.6-fold and the ratio of eIF2α(P)/eIF2α increases from 0.22±0.11 to 0.52±0.08, implicating eIF2α phosphorylation in the downregulation of protein synthesis during estivation in this animal. The differences in the amounts of eIF2α and the level of its phosphorylation between these two species also suggest possible differences either in the mechanism by which protein synthesis is downregulated during estivation or in the sensitivity of the initiation of translation to eIF2α(P) levels.
Evolution of thermotolerance and the heat-shock response: evidence from inter/intraspecific comparison and interspecific hybridization in the virilis species group of Drosophila. I. Thermal phenotype
Authors: Garbuz David , Evgenev Michael B. , Feder Martin E. , Zatsepina Olga G.
Published: June 2003

Species in the virilis group of Drosophila (fruit flies),which overlap or replace one another along climatic gradients, exhibit corresponding differences in basal thermotolerance, inducible thermotolerance and the heat-shock response. The low-latitude species D. virilisexceeds the high-latitude species D. lummei in these measures of thermotolerance, the temperature threshold for heat-shock factor (HSF)activation and the ability to express hsp70 mRNA and diverse heat-shock proteins (e.g. Hsp70, Hsp83 and small Hsps) after intense heat shock (e.g. 40–41°C). The xeric species D. novamexicanadiffers from the mesic species D. texana in much the same way for many of these traits. By contrast, intraspecific variation in these traits is small. Because D. virilis and D. lummei can readily be crossed to yield partially fertile progeny, genetic analysis of interspecific differences is possible. Interspecific hybrids are intermediate to the parental species in basal thermotolerance and inducible thermotolerance and resemble D. virilis in Hsp concentrations after intense heat shock and Hsp70 protein electromorphs.
The spectral input to honeybee visual odometry
Authors: Chittka Lars , Tautz Jürgen
Published: June 2003

Bees returning from a feeder placed in a narrow tunnel that is lined with a chequered pattern will strongly overestimate travel distance. This finding supports the view that their distance estimation is based on integrating optic flow experienced during flight. Here, we use chequered tunnels with various colour combinations as a tool to identify the spectral channel used by bees to gauge travel distance. The probability of bees performing waggle dances after a short travel distance correlates only with the low range of the green contrast of the pattern in the tunnel. But it does not correlate with the pattern's chromatic contrast or brightness contrast. Distance estimation is therefore colour blind. We also evaluated the waggle runs as a function of colour pattern. Their duration is the code for the food source distance. Waggle run duration is entirely independent of the colour pattern used,implying that once green contrast is above detection threshold, distance estimation depends solely on the angular motion of the landscape passed in flight.
Effects of social interaction on the electric organ discharge in a mormyrid fish, Gnathonemus petersii (Mormyridae, Teleostei)
Authors: Terleph Thomas A. , Moller Peter
Published: June 2003

African weakly discharging electric fish (Mormyridae) use their self-generated electric signals and electroreceptive abilities for orientation and communication in the context of courtship and territorial interactions. This paper documents socially mediated changes in the electric organ discharge(EOD) of subadult Gnathonemus petersii under non-breeding environmental conditions. Increases in EOD duration and changes in the relative phase amplitudes occurred in dominant fish during same-sex(male–male, female–female) and opposite-sex interactions. Similar changes were also observed in fish that were restricted in their physical interactions, suggesting that direct contact is not necessary to induce dominance-typical EOD waveforms. The possible communicative functions of these changes are discussed.
cGMP-dependent changes in phototaxis: a possible role for the foraging gene in honey bee division of labor
Authors: Ben-Shahar Y. , Leung H.-T. , Pak W. L. , Sokolowski M. B. , Robinson G. E.
Published: June 2003

Division of labor in honey bee colonies is influenced by the foraging gene (Amfor), which encodes a cGMP-dependent protein kinase (PKG). Amfor upregulation in the bee brain is associated with the age-related transition from working in the hive to foraging for food outside, and cGMP treatment (which increases PKG activity)causes precocious foraging. We present two lines of evidence in support of the hypothesis that Amfor affects division of labor by modulating phototaxis. We first show that a subset of worker bees involved in the removal of corpses from the hive had forager-like brain levels of Amfor brain expression despite being middle aged; age-matched food-handlers, who do not leave the hive to perform their job, had low levels of Amforexpression. This finding suggests that occupations that involve working outside the hive are associated with high levels of Amfor in brain. Secondly, foragers were much more positively phototactic than hive bees in a laboratory assay, and cGMP treatment caused a precocious onset of positive phototaxis. The cGMP effect was not due to a general increase in behavioral activity; cGMP treatment had no effect on locomotor activity under either constant darkness or a light:dark regime. The cGMP effect also was not due to changes in circadian rhythmicity; cGMP treatment had no effect on age at onset of locomotor circadian rhythmicity or the period of rhythmicity. The effects of Amfor on phototaxis are not related to peripheral processing;electroretinogram analysis revealed no effect of cGMP treatment on photoreceptor activity and no differences between untreated hive bees and foragers. The cAMP/PKA pathway does not appear to be playing a similar role to cGMP/PKG in the honey bee; cAMP treatment did not affect phototaxis and gene expression analysis revealed task-related differences only for the gene encoding the regulatory subunit, but not the catalytic subunit, of PKA. Our findings implicate one neural process associated with honey bee division of labor that can be affected by naturally occurring changes in the expression of Amfor.
Effects of the local mechanical environment on vertebrate tissue differentiation during repair: does repair recapitulate development?
Authors: Cullinane Dennis M. , Salisbury Kristy T. , Alkhiary Yaser , Eisenberg Solomon , Gerstenfeld Louis , Einhorn Thomas A.
Published: June 2003

The local mechanical environment is a crucial factor in determining cell and tissue differentiation during vertebrate skeletal development and repair. Unlike the basic response of bone to mechanical load, as described in Wolff's law, the mechanobiological relationship between the local mechanical environment and tissue differentiation influences everything from tissue type and molecular architecture to the formation of complex joints. This study tests the hypothesis that precisely controlled mechanical loading can regulate gene expression, tissue differentiation and tissue architecture in the adult skeleton and that precise manipulation of the defect's local mechanical environment can initiate a limited recapitulation of joint tissue development. We generated tissue type predictions using finite element models (FEMs)interpreted by published mechanobiological fate maps of tissue differentiation. The experiment included a custom-designed external fixator capable of introducing daily bending, shear or a combination of bending and shear load regimens to induce precisely controlled mechanical conditions within healing femoral defects. Tissue types and ratios were characterized using histomorphometrics and molecular markers. Tissue molecular architecture was quantified using polarized light and Fourier transforms, while immunological staining and in situ hybridization were used to characterize gene expression. The finite element models predicted the differentiation of cartilage within the defects and that substantial fibrous tissues would develop along the extreme excursion peripheries in the bending group. The three experimentally induced loading regimens produced contiguous cartilage bands across all experimental defects, inhibiting bony healing. Histomorphometric analysis of the ratios of cartilage to bone in the experimental groups were not significantly different from those for the knee joint, and Fourier transform analysis determined significantly different collagen fibril angle specializations within superficial, intermediate and deep layers of all experimental cartilages (P<0.0001),approximating those for articular cartilage. All stimulations resulted in the expression of collagen type II, while the bending stimulation also resulted in the expression of the joint-determining gene GDF-5. These findings indicate that the local mechanical environment is an important regulator of gene expression, tissue differentiation and tissue architecture.
The swamp eelMonopterus albusreduces endogenous ammonia production and detoxifies ammonia to glutamine during 144 h of aerial exposure
Authors: Tay Angeline S. L. , Chew Shit F. , Ip Yuen K.
Published: June 2003

The swamp eel Monopterus albus inhabits muddy ponds, swamps,canals and rice fields, where it can burrow within the moist earth during the dry summer season, thus surviving for long periods without water. This study aimed to elucidate the strategies adopted by M. albus to defend against endogenous ammonia toxicity when kept out of water for 144 h (6 days). Like any other fish, M. albus has difficulties in excreting ammonia during aerial exposure. In fact, the rates of ammonia and urea excretions decreased significantly in specimens throughout the 144 h of aerial exposure. At 144 h, the ammonia and urea excretion rates decreased to 20% and 25%,respectively, of the corresponding control values. Consequently, ammonia accumulated to high levels in the tissues and plasma of the experimental specimens. Apparently, M. albus has developed relatively higher ammonia tolerance at the cellular and subcellular levels compared with many other teleost fish. Since the urea concentration in the tissues of specimens exposed to air remained low, urea synthesis was apparently not adopted as a strategy to detoxify endogenous ammonia during 144 h of aerial exposure. Instead, ammonia produced through amino acid catabolism was detoxified to glutamine, leading to the accumulation of glutamine in the body during the first 72 h of aerial exposure. Complimenting the increased glutamine formation was a significant increase in glutamine synthetase activity in the liver of specimens exposed to air for 144 h. Formation of glutamine is energetically expensive. It is probably because M. albus remained relatively inactive on land that the reduction in energy demand for locomotory activity facilitated its exploitation of glutamine formation to detoxify endogenous ammonia. There was a slight decrease in the glutamine level in the body of the experimental animals between 72 h and 144 h of aerial exposure, which indicates that glutamine might not be the end product of nitrogen metabolism. In addition, these results suggest that suppression of endogenous ammonia production, possibly through reductions in proteolysis and amino acid catabolism, acts as the major strategy to avoid ammonia intoxication in specimens exposed to air for ≥72 h. It is concluded that glutamine formation and reduction in ammonia production together served as effective strategies to avoid the excessive accumulation of ammonia in the body of M. albus during 144 h of aerial exposure. However, these strategies might not be adequate to sustain the survival of M. albus in the mud for longer periods during drought because ammonia and glutamine concentrations had already built up to high levels in the body of specimens exposed to air for 144 h.
Freezing and anoxia stresses induce expression of metallothionein in the foot muscle and hepatopancreas of the marine gastropodLittorina littorea
Authors: English Tamara E. , Storey Kenneth B.
Published: June 2003

Differential screening of cDNA libraries constructed from the foot muscle of marine snails Littorina littorea revealed several cDNAs that are upregulated during anoxia or freezing exposures, environmental stresses that are naturally endured by this species. One full-length clone of 1196 nucleotides (GenBank accession number AY034179) hybridized with a 1200-nucleotide band on northern blots and encoded a 100-amino-acid protein that was identified as belonging to the metallothionein (MT) family. L. littorea MT shared 45% and 56% identity with the copper- and cadmium-binding MT isoforms, respectively, from another gastropod, Helix pomatia and 43–47% identity with marine bivalve MTs. The L. littorea sequence included the mollusc-specific C-terminal motif Cys-X-Cys-X(3)-Cys-Thr-Gly-X(3)-Cys-X-Cys-X(3)-Cys-X-Cys-Lys that identifies it as a family 2 (mollusc) MT. Northern blot analysis showed that L. littorea MT was upregulated in both foot muscle and hepatopancreas in response to both freezing and anoxia stresses; within 1 h of the beginning of the stress transcript levels rose 2.5- to sixfold of control levels, reaching maximal levels at 12 or 24 h. After 24 h recovery from either stress,transcript levels were reduced again in three cases but remained elevated in hepatopancreas from anoxia-treated snails. Upregulation of MT during environmental stress could serve one or more possible roles, including a function in antioxidant defense.
Are uniform regional safety factors an objective of adaptive modeling/remodeling in cortical bone?
Authors: Skedros John G. , Dayton Michael R. , Sybrowsky Christian L. , Bloebaum Roy D. , Bachus Kent N.
Published: June 2003

It has been hypothesized that a major objective of morphological adaptation in limb-bone diaphyses is the achievement of uniform regional safety factors between discrete cortical locations (e.g. between cranial and caudal cortices at mid-diaphysis). This hypothesis has been tested, and appears to be supported in the diaphyses of ovine and equine radii. The present study more rigorously examined this question using the equine third metacarpal (MC3),which has had functionally generated intracortical strains estimated by a sophisticated finite element model. Mechanical properties of multiple mid-diaphyseal specimens were evaluated in both tension and compression,allowing for testing of habitually tensed or compressed regions in their respective habitual loading mode (`strain-mode-specific' loading). Elastic modulus, and yield and ultimate strength and strain, were correlated with in vivo strain data from a previously published finite element model. Mechanical tests revealed minor variations in elastic modulus, and yield and ultimate strength in both tension and compression loading, while physiological strains varied significantly between the cortices. Contrary to the hypothesis of uniform safety factors, the MC3 has a broad range of tension (caudo-medial,4.0; cranio-lateral, 37.7) and compression (caudo-medial, 5.7; cranio-lateral,68.9) safety factors.
Food supplements modulate changes in leucocyte numbers in breeding male ground squirrels
Authors: Bachman Gwendolyn C.
Published: June 2003

Immunosuppression may be an important cost of reproduction in breeding males. It can result from elevated levels of testosterone or stress hormones and may serve to lower the energetic cost of maintaining immune function at a time of high demand. This suggests that greater access to energy resources could reduce immunosuppression as a cost of reproduction, minimizing the trade-off between energetic investment in current reproductive effort and survival. I examined the impact of food availability on immune function by provisioning male Belding's ground squirrels in the field from the time they emerged from hibernation to the start of breeding. Temporal changes in immune status, measured by leucocyte counts, differed between provisioned males and un-provisioned controls. Provisioning advanced the increase in lymphocytes and neutrophils from after breeding to before. At the start of breeding, the leucocyte count was three times greater in provisioned males than in controls and was still nearly twice as great at the end of breeding. Control males increased all leucocyte numbers after breeding. This experiment demonstrates that variation in food intake can lead to individual variation in the extent of immunosuppression during breeding and therefore that reduced immune function may not be an obligatory cost of reproduction.
Optical engineering: Diagnostics for industrial applications
Authors: Halliwell N A , Hargrave G K
Published: June 2003

Optical engineering uses research and development of laser technology, modern photonic detection/imaging systems and optical metrology for engineering applications. It has produced a wide range of processes and techniques from high-power laser material processing to high-sensitivity metrology and has applications in every industrial sector. Modern optical diagnostic techniques are providing new experimental and in situ data, which hitherto were considered to be unobtainable. Engineers are analysing these data in order to provide immediate design improvements in the performance of components. In addition, they use the data to refine theoretical/computer models of engineering processes, which in turn provide more accurate performance prediction. This paper introduces technology now available to the optical engineer and describes how it is being used to provide optical diagnostic techniques for both solid and fluid mechanics applications in industry. The gas industry has to deal with gas provision safely and efficiently from ‘drill bit to burner tip’ and has benefited significantly from optical engineering. Examples of optical diagnostic techniques and applications, which are used to improve this process, are described.
Weak shock reflection from an open end of a tube with a baffle plate
Authors: Kim H D , Kweon Y H , Setoguchi T , Aoki T
Published: June 2003

The present paper describes experimental and numerical investigations of a new boundary condition at an open end of a tube, in which a weak shock wave is discharged towards the surroundings. Experimental and computational investigations were performed on a simple shock tube with and without baffle plates. A numerical calculation was carried out for an unsteady, axisymmetric, inviscid, compressible flow. The size of baffle plate was varied in order to understand its effect on the reflection of the weak shock wave from the open end of the tube. With and without a baffle plate, the results of the experiment were in good agreement with those of numerical calculations. The results showed that an open end correction is subject to the presence of a baffle plate at the open end. An improved empirical equation for the reflection of the weak shock wave from the open end of a duct with and without a baffle plate was developed.
Finite element analysis of a cylindrical approach for shrink-fit precision gear forging dies
Authors: Kutuk M A , Eyercioglu O , Yildirim N , Akpolat A
Published: June 2003

The design of shrink-fit precision gear forging dies based on strength considerations using an analytical (thick-wall cylinders) approach and the finite element method are compared. While the two methods, analytical and finite element, agree well for the dies with no irregularities (gear teeth), the finite element method predicts much higher stress values than those of the analytical approach for the dies with gear teeth. These high stresses are considerably reduced by reoptimizing the geometric parameters, such as the interference between the die and the ring.
Mathematical modelling of rotary vane engines
Authors: Tucker R W , Wang C , Librovich B V
Published: June 2003

This paper introduces mathematical modelling techniques that are designed to analyse the dynamic behaviour of a class of rotary vane engines. These engines employ non-circular gears for the transmission of primary torque and the modelling explores ways to ensure that torque fluctuations in the flywheel are small. The basic physical principles of rigid-body dynamics are used to formulate a system of non-linear ordinary differential equations describing the rolling motion of two-dimensional rigid laminae. It is argued that such a system offers a valuable first approximation for the study of a realistic engine consisting of two connected combustion units.
Formulations of thermodynamic properties of supersaturated moist air
Authors: Mago P J , Sherif S A
Published: June 2003

Supersaturated air exits whenever the amount of moisture present is larger than the amount that the air can carry at the prevailing air temperature. Applications involving supersaturated air include aircraft wing icing problems and industrial walk-in freezers operating at low temperatures. The ability to predict frost and ice formation patterns on cold surfaces in supersaturated air has historically been impeded by the lack of property data. The objective of this paper is thus to provide a methodology for deriving key properties of air under supersaturated conditions for the purpose of improving the prediction capability in situations involving simultaneous heat and mass transfer in supersaturated air.
Rapid Magnetic Resonance Imaging vs Radiographs for Patients With Low Back Pain
Authors: Jarvik Jeffrey G. , Hollingworth William , Martin Brook , Emerson Scott S. , Gray Darryl T. , Overman Steven , Robinson David , Staiger Thomas , Wessbecher Frank , Sullivan Sean D. , Kreuter William , Deyo Richard A.
Published: June 2003

Context

Faster magnetic resonance imaging (MRI) scanning has made MRI a potential cost-effective replacement for radiographs for patients with low back pain. However, whether rapid MRI scanning results in better patient outcomes than radiographic evaluation or a cost-effective alternative is unknown.

Objective

To determine the clinical and economic consequences of replacing spine radiographs with rapid MRI for primary care patients.

Design, Setting, and Patients

Randomized controlled trial of 380 patients aged 18 years or older whose primary physicians had ordered that their low back pain be evaluated by radiographs. The patients were recruited between November 1998 and June 2000 from 1 of 4 imaging centers in the Seattle, Wash, area: a university-based teaching program, a nonuniversity-based teaching program, and 2 private clinics.

Intervention

Patients were randomly assigned to receive lumbar spine evaluation by rapid MRI or by radiograph.

Main Outcome Measures

Back-related disability measured by the modified Roland questionnaire. Secondary outcomes included Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), pain, preference scores, satisfaction, and costs.

Results

At 12 months, primary outcomes of functional disability were obtained from 337 (89%) of the 380 patients enrolled. The mean back-related disability modified Roland score for the 170 patients assigned to the radiograph evaluation group was 8.75 vs 9.34 for the 167 patients assigned the rapid MRI evaluation group (mean difference, −0.59; 95% CI, −1.69 to 0.87). The mean differences in the secondary outcomes were not statistically significant : pain bothersomeness (0.07; 95% CI −0.88 to 1.22), pain frequency (0.12; 95% CI, −0.69 to 1.37), and SF-36 subscales of bodily pain (1.25; 95% CI, −4.46 to 4.96), and physical functioning (2.73, 95% CI −4.09 to 6.22). Ten patients in the rapid MRI group vs 4 in the radiograph group had lumbar spine operations (risk difference, 0.34; 95% CI, −0.06 to 0.73). The rapid MRI strategy had a mean cost of $2380 vs $2059 for the radiograph strategy (mean difference, $321; 95% CI, −1100 to 458).

Conclusions

Rapid MRIs and radiographs resulted in nearly identical outcomes for primary care patients with low back pain. Although physicians and patients preferred the rapid MRI, substituting rapid MRI for radiographic evaluations in the primary care setting may offer little additional benefit to patients, and it may increase the costs of care because of the increased number of spine operations that patients are likely to undergo.
Belt-Positioning Booster Seats and Reduction in Risk of Injury Among Children in Vehicle Crashes
Authors: Durbin Dennis R. , Elliott Michael R. , Winston Flaura K.
Published: June 2003

Context

Although more than a dozen states have ratified laws that require booster seats for children older than 4 years, most states continue to have child restraint laws that only cover children through age 4 years. Lack of booster seat effectiveness data may be a barrier to passage of stronger child restraint laws.

Objectives

To quantify the association of belt-positioning booster seats compared with seat belts alone and risk of injury among 4- to 7-year-old children and to assess patterns of injury among children in booster seats vs seat belts.

Design, Setting, and Population

Cross-sectional study of children aged 4 to 7 years in crashes of insured vehicles in 15 states, with data collected via insurance claims records and a telephone survey. A probability sample of 3616 crashes involving 4243 children, weighted to represent 56 593 children in 48 257 crashes was collected between December 1, 1998, and May 31, 2002.

Main Outcome Measure

Parent report of clinically significant injuries.

Results

Injuries occurred among 1.81% of all 4- to 7-year-olds, including 1.95% of those in seat belts and 0.77% of those in belt-positioning booster seats. The odds of injury, adjusting for child, driver, crash, and vehicle characteristics, were 59% lower for children aged 4 to 7 years in belt-positioning boosters than in seat belts (odds ratio, 0.41; 95% confidence interval, 0.20-0.86). Children in belt-positioning booster seats had no injuries to the abdomen, neck/spine/back, or lower extremities, while children in seat belts alone had injuries to all body regions.

Conclusion

Belt-positioning booster seats were associated with added safety benefits compared with seat belts to children through age 7 years, including reduction of injuries classically associated with improper seat belt fit in children.
Length of Stay in Home Care Before and After the 1997 Balanced Budget Act
Authors: Murkofsky Rachel L. , Phillips Russell S. , McCarthy Ellen P. , Davis Roger B. , Hamel Mary Beth
Published: June 2003

Context

Prior to 1997, home health agencies (HHAs) were reimbursed on a fee-for-service basis and had incentives to provide more services. The 1997 Balanced Budget Act (BBA) reduced payments for home care services to help control Medicare spending.

Objective

To examine the length of stay in home care before and after the 1997 BBA.

Design and Setting

Cross-sectional study of home care patients in the 1996 and 1998 National Home and Hospice Care Surveys, which surveyed 1053 HHAs in 1996 and 1088 HHAs in 1998.

Patients

Nationally representative random sample of home care patients with Medicare coverage in 1996 (4127 patients) and 1998 (4051 patients).

Main Outcome Measure

Length of stay in home care (based on the number of days a patient was enrolled in home care services).

Results

From 1996 to 1998, unadjusted median length of stay decreased by 16 days for all home care patients (60-44 days, P = .002). The decrease affected for-profit HHAs more than not-for-profit HHAs (111-55 days [51% decrease, P = .002] vs 46-36 days [22% decrease, P = .042]). In a Cox proportional hazards model of time to discharge from home care, post-BBA year (1998) was associated with a shorter length of stay in home care (adjusted hazard ratio [aHR] for home care discharge, 1.39 [95% confidence interval {CI}, 1.19-1.61]), and for-profit status was associated with a longer length of stay in home care (aHR, 0.82 [95% CI, 0.71-0.94]) after adjusting for patient demographics, diagnoses, and functional status.

Conclusion

After the 1997 BBA, length of stay in home care decreased among Medicare patients, particularly among those receiving care from for-profit HHAs.
Changes in Rates of Autopsy-Detected Diagnostic Errors Over Time
Authors: Shojania Kaveh G. , Burton Elizabeth C. , McDonald Kathryn M. , Goldman Lee
Published: June 2003

Context

Substantial discrepanies exist between clinical diagnoses and findings at autopsy. Autopsy may be used as a tool for quality management to analyze diagnostic discrepanies.

Objective

To determine the rate at which autopsies detect important, clinically missed diagnoses, and the extent to which this rate has changed over time.

Data Sources

A systematic literature search for English-language articles available on MEDLINE from 1966 to April 2002, using the search terms autopsy, postmortem changes, post-mortem, postmortem, necropsy, and posthumous, identified 45 studies reporting 53 distinct autopsy series meeting prospectively defined criteria. Reference lists were reviewed to identify additional studies, and the final bibliography was distributed to experts in the field to identify missing or unpublished studies.

Study Selection

Included studies reported clinically missed diagnoses involving a primary cause of death (major errors), with the most serious being those likely to have affected patient outcome (class I errors).

Data Extraction

Logistic regression was performed using data from 53 distinct autopsy series over a 40-year period and adjusting for the effects of changes in autopsy rates, country, case mix (general autopsies; adult medical; adult intensive care; adult or pediatric surgery; general pediatrics or pediatric inpatients; neonatal or pediatric intensive care; and other autopsy), and important methodological features of the primary studies.

Data Synthesis

Of 53 autopsy series identified, 42 reported major errors and 37 reported class I errors. Twenty-six autopsy series reported both major and class I error rates. The median error rate was 23.5% (range, 4.1%-49.8%) for major errors and 9.0% (range, 0%-20.7%) for class I errors. Analyses of diagnostic error rates adjusting for the effects of case mix, country, and autopsy rate yielded relative decreases per decade of 19.4% (95% confidence interval [CI], 1.8%-33.8%) for major errors and 33.4% (95% [CI], 8.4%-51.6%) for class I errors. Despite these decreases, we estimated that a contemporary US institution (based on autopsy rates ranging from 100% [the extrapolated extreme at which clinical selection is eliminated] to 5% [roughly the national average]), could observe a major error rate from 8.4% to 24.4% and a class I error rate from 4.1% to 6.7%.

Conclusion

The possibility that a given autopsy will reveal important unsuspected diagnoses has decreased over time, but remains sufficiently high that encouraging ongoing use of the autopsy appears warranted.
14q(22) deletion in a familial case of anophthalmia with polydactyly
Authors: Ahmad M.E. , Dada Rima , Dada Tanuj , Kucheria Kiran
Published: June 2003

We report a family of anophthalmia with ocular and extraocular manifestations. The proband, his three sisters, and two sons had anophthalmia and preaxial polydactyly in the right hand. Cytogenetic analysis was done for the proband and two of his sons, one of whom was affected. Another male child was affected but was not available for cytogenetic analysis. Karyotypes of both affected individuals showed deletion on long arm of 14q22q23. Literature review shows four cases of anophthalmia with extra ocular anomalies associated with 14q (q22q23) deletion. Recently it has been suggested that the human homeobox gene, SIX6, and the BMP‐4 gene are responsible for eye development. Both are located in the chromosome 14q22.3‐q23 region. Deletion in this region has been known to be associated with anophthalmia and pituitary anomalies. This is the first family of anophthalmia, which showed polydactyly with a chromosomal deletion in the 14q22‐q23 region and its familial transmission in two generations with a total of six affected individuals. © 2003 Wiley‐Liss, Inc.
Margareta Mikkelsen
Authors: Miao Jinmin
Published: June 2003

Margareta Mikkelsen, a well‐known Danish cytogeneticist, started to research autosome aberrations in 1959 and built the first chromosome laboratory at the University of Copenhagen with Anders Frøland. In 1968, she developed a fully functional chromosome laboratory from scratch at the John F. Kennedy Institute (JFKI). Not only the laboratory performed diagnoses all over Denmark, but also it is a sole place among all the departments of human genetics to train Danes to be clinical geneticists. A generation of Danish geneticists grew up under Dr. Mikkelsen's wing. Dr. Mikkelsen played a pioneering role in research on Down syndrome (DS) and exploring the source of the extra chromosome 21 remains her main interest. She performed the first case of prenatal diagnosis by amniocentesis in Denmark and since then, she was active in this field. The JFKI also committed to research on the fragile X syndrome. Dr. Mikkelsen took on many public responsibilities in Denmark and in Europe. She was on the board of many Danish scientific organizations and an active member of the European Society of Human Genetics (ESHG). She was efficient in public education with communication in lay language. After her retirement, she was more dynamic in medical ethics. Born as Irmtraud Wieser in Munich, Dr. Mikkelsen walked through the hardship of pre‐war Germany, the inferno of the World War II, the trauma brought by her two husbands' alienation, the obstacles in work, and physical ailment to fulfill her unwavering commitment to human genetics. © 2003 Wiley‐Liss, Inc.