bluuebunny/crossref_metadata_2025 huggingface dataset:
Validity of Measures Is No Simple Matter
Authors: Sechrest Lee
Published: September 2005

Purpose and Method. This article aims to promote a better understanding of the nature of measurement, the special problems posed by measurement in the social sciences, and the inevitable limitations on inferences in science (so that results are not overinterpreted), by using the measurement of blood pressure as an example. As it is necessary to raise questions about the meaning and extent of the validity of something as common as measured blood pressure, even more serious questions are unavoidable in relation to other commonly used measures in social science. The central issue is the validity of the inferences about the construct rather than the validity of the measure per se.

Conclusion. It is important to consider the definition and validity of the construct at issue as well as the adequacy of its representation in the measurement instrument. By considering a particular construct within the context of a conceptual model, researchers and clinicians will improve their understanding of the construct's validity as measured.
Integrating Validity Theory with Use of Measurement Instruments in Clinical Settings
Authors: Adam Kelly P. , O'Malley Kimberly J. , Kallen Michael A. , Ford Marvella E.
Published: September 2005

Objective. To present validity concepts in a conceptual framework useful for research in clinical settings.

Principal Findings. We present a three‐level decision rubric for validating measurement instruments, to guide health services researchers step‐by‐step in gathering and evaluating validity evidence within their specific situation. We address construct precision, the capacity of an instrument to measure constructs it purports to measure and differentiate from other, unrelated constructs; quantification precision, the reliability of the instrument; and translation precision, the ability to generalize scores from an instrument across subjects from the same or similar populations. We illustrate with specific examples, such as an approach to validating a measurement instrument for veterans when prior evidence of instrument validity for this population does not exist.

Conclusions. Validity should be viewed as a property of the interpretations and uses of scores from an instrument, not of the instrument itself: how scores are used and the consequences of this use are integral to validity. Our advice is to liken validation to building a court case, including discovering evidence, weighing the evidence, and recognizing when the evidence is weak and more evidence is needed.
Managed Care Market Share and Primary Treatment for Cancer
Authors: Keating Nancy L. , Landrum Mary Beth , Meara Ellen , Ganz Patricia A. , Guadagnoli Edward
Published: September 2005

Objective. Increases in the market share of managed care are associated with decreases in expenditures in the fee‐for‐service sector. To understand utilization patterns responsible for such savings, we assessed whether increases in managed care market share were related to increases in receipt of equally effective but less costly primary cancer therapies.

Data Sources. Cancer registry data linked to Medicare administrative data for a population‐based sample of fee‐for‐service Medicare beneficiaries 66 years and older who were diagnosed with breast or prostate cancer during 1993–1999.

Study Design. We used fixed‐effects regression models to assess whether county‐level increases in the market share of managed care were associated with differences in receipt of cancer therapies that are similar in effectiveness but vary in cost.

Principal Findings. Increases in the market share of managed care were not associated with differences in the receipt of mastectomy versus breast‐conserving surgery with radiation for women with early stage breast cancer (p=.47) or with the receipt of conservative therapy (versus surgery or radiation therapy) for men with local or regional prostate cancer (p=.30).

Conclusions. Increases in the market share of managed care do not appear to influence the receipt of equally effective primary treatments for cancer in the fee‐for‐service sector.
H. pylori Infection Increases Levels of Exhaled Nitrate
Authors: Lechner Matthias , Karlseder Alban , Niederseer David , Lirk Philipp , Neher Andreas , Rieder Josef , Tilg Herbert
Published: September 2005

Background.  Helicobacter pylori infection is one of the most common chronic bacterial infections worldwide. Despite the existence of a breath test for the diagnosis of H. pylori infection, no study has described the composition of volatile compounds, especially the levels of nitrate, in the exhaled air of patients with H. pylori infection.

Materials and Methods.  The volatile compounds in the exhaled air of 14 patients suffering from H. pylori gastritis and 11 controls were analyzed using proton transfer reaction –mass spectrometry. Gastric biopsy was used to establish diagnosis of current H. pylori infection.

Results.  Comparing mass spectra between groups, Mass 28 (hydrogen cyanide, HCN) and Mass 64 (hydrogen nitrate, H2NO3) were found to be significantly elevated in patients with H. pylori infection.

Conclusions.  The main result of the present study is that in H. pylori‐infected patients, levels of exhaled hydrogen nitrate and hydrogen cyanide are found to be significantly elevated. However, further studies are necessary to find out whether the differences in the detected mass spectrum are specific enough to differentiate patients with H. pylori gastritis from healthy controls.
Detection of Non‐pylori Helicobacter Species in “Helicobacter heilmannii”‐Infected Humans
Authors: De Groote Dominic , Van Doorn Leen‐Jan , Van den Bulck Kathleen , Vandamme Peter , Vieth Michael , Stolte Manfred , Debongnie Jean‐Claude , Burette Alain , Haesebrouck Freddy , Ducatelle Richard
Published: September 2005

Background.  A small proportion of patients suffering from chronic active gastritis are diagnosed with gastric Helicobacter species other than Helicobacter pylori. Circumstantial evidence has suggested that these bacteria, also referred to as “Helicobacter heilmannii”‐like organisms (HHLO), may be transmitted through animals. The isolation of a Helicobacter bizzozeronii strain from a human patient confirmed this hypothesis. It was the aim of the present study to assess the presence of animal Helicobacter species and H. pylori in humans infected with HHLO, as diagnosed by histology.

Methods.  Paraffin‐embedded gastric biopsy specimens of 108 HHLO‐infected patients (42 women and 66 men) from three clinical centers were screened for the presence of animal gastric Helicobacter species by polymerase chain reaction (PCR), using assays targeting the 16S rDNA region of the three known canine and feline helicobacters (H. bizzozeronii, H. salomonis and H. felis), “Candidatus H. suis”, and “Candidatus H. bovis”. In addition, the presence of H. pylori was evaluated by multiplex PCR analysis.

Results.  In 63.4% of the stomachs (64/101) classification of the Helicobacter infection into the above mentioned groups was achieved. Non‐pylori Helicobacter species commonly colonizing the stomachs of cats and dogs were found in 48.5% (49/101) of the patients. Fourteen (13.9%) samples tested positive for “Candidatus H. suis”, and “Candidatus H. bovis” was demonstrated in 1 (0.9%) patient. The presence of H. pylori was established in 13 patients (12.9%). Eleven stomachs (10.9%) were infected with at least two different Helicobacter species.

Conclusions.  This study identifies animal Helicobacter species in the stomach of a large series of HHLO‐infected patients, which may have clinical implications in a subset of patients with gastric disease.
Eradication of Helicobacter pylori and Resolution of Gastritis in the Gastric Mucosa of IL‐10‐Deficient Mice
Authors: Matsumoto Yuko , Blanchard Thomas G. , Drakes Maureen L. , Basu Malini , Redline Raymond W. , Levine Alan D. , Czinn Steven J.
Published: September 2005

Background.  Helicobacter pylori has been shown to induce pronounced gastric inflammation in the absence of interleukin‐10 (IL‐10) by 6 weeks post inoculation. The ability of IL‐10−/– mice to eradicate H. pylori has not been demonstrated, possibly due to early sacrifice. Therefore, the long‐term effect of enhanced gastritis on H. pylori colonization was determined in IL‐10−/– mice.

Methods.  C57BL/6 and IL‐10−/– mice were infected with H. pylori and assessed for the degree of gastritis, bacterial load, and in vitro T‐cell recall response at 4 and 16 weeks of infection.

Results.  Infection of IL‐10−/– mice resulted in significantly more severe gastritis than wild‐type control mice and eradication of H. pylori by 4 weeks post inoculation. By 16 weeks, the level of gastritis in IL‐10−/– was reduced to the levels observed in wild‐type mice. Splenocytes from IL‐10−/– mice were prone to produce significantly greater amounts of IFN‐γ than wild‐type mice when stimulated with bacterial antigens.

Conclusions.  These results indicate that the host is capable of spontaneously eradicating H. pylori from the gastric mucosa when inflammation is elevated beyond the chronic inflammation induced in wild‐type mice, and that the gastritis dissipates following bacterial eradication. Additionally, these data provide support for a model of gastrointestinal immunity in which naturally occurring IL‐10‐producing regulatory T cells modulate the host response to gastrointestinal bacteria.
An Empirical Analysis of the Dynamic Relation between Investment‐Grade Bonds and Credit Default Swaps
Authors: BLANCO ROBERTO , BRENNAN SIMON , MARSH IAN W.
Published: September 2005

We test the theoretical equivalence of credit default swap (CDS) prices and credit spreads derived by Duffie (1999), finding support for the parity relation as an equilibrium condition. We also find two forms of deviation from parity. First, for three firms, CDS prices are substantially higher than credit spreads for long periods of time, arising from combinations of imperfections in the contract specification of CDSs and measurement errors in computing the credit spread. Second, we find short‐lived deviations from parity for all other companies due to a lead for CDS prices over credit spreads in the price discovery process.
Stochastic Convenience Yield Implied from Commodity Futures and Interest Rates
Authors: CASASSUS JAIME , COLLIN‐DUFRESNE PIERRE
Published: September 2005

We characterize a three‐factor model of commodity spot prices, convenience yields, and interest rates, which nests many existing specifications. The model allows convenience yields to depend on spot prices and interest rates. It also allows for time‐varying risk premia. Both may induce mean reversion in spot prices, albeit with very different economic implications. Empirical results show strong evidence for spot‐price level dependence in convenience yields for crude oil and copper, which implies mean reversion in prices under the risk‐neutral measure. Silver, gold, and copper exhibit time variation in risk premia that implies mean reversion of prices under the physical measure.
Trends in Corporate Governance
Authors: HERMALIN BENJAMIN E.
Published: September 2005

The popular press and scholarly studies have noted a number of trends in corporate governance. This article addresses, from a theoretical perspective, whether these trends are linked. And, if so, how? The article finds that a trend toward greater board diligence will lead, sometimes through subtle or indirect mechanisms, to trends toward more external candidates becoming CEO, shorter tenures for CEOs, more effort/less perquisite consumption by CEOs (even though such behavior is not directly monitored), and greater CEO compensation. An additional prediction is that, under plausible conditions, externally hired CEOs should have shorter tenures, on average, than internally hired CEOs.
Comparison of osteoblast spreading on microstructured dental implant surfaces and cell behaviour in an explant model of osseointegration
Authors: Sammons Rachel L. , Lumbikanonda Narong , Gross Michael , Cantzler Philip
Published: September 2005

Objectives: To compare interactions between rat calvarial osteoblasts and titanium dental implants with different microstructured surfaces.

Material and methods: Seven commercially available implants were used. Surfaces included plasma‐sprayed, grit‐blasted and/or acid‐etched, smooth‐machined and anodised titanium. Two methods were used to compare cell behaviour: (1) A cell‐spreading assay in which percentages of cells at four different stages of attachment were identified by scanning electron microscopy and quantified within a 30 min attachment period. (2) Implants were placed in ‘pocket culture’ within nylon mesh sacs in contact with explanted calvarial bone fragments for 2 and 4 weeks.

Results: Surfaces combining grit blasting and acid etching, of microporous topography, showed significantly enhanced rates of cell spreading in comparison with the others. Differential cell morphology was observed in both suspension assays and pocket cultures. In the latter, cells migrated onto all surfaces. Multicellular layers with extracellular matrix (ECM) were present between the layers and on the material surfaces after 2 weeks. After 4 weeks, cell layers were more consolidated, and microstructures were obscured by layers of cells and ECM. Mineralised tissue was seen in association with ECM on grit‐blasted surfaces of rough and smooth microtopography.

Conclusions: The two methods provided complementary information: a rough surface of porous microstructure may enhance the rate of cell spreading. Differentiation and calcification occurred on surfaces of both rough and smooth microstructure.
Fluorescence Approaches for Determining Protein Conformations, Interactions and Mechanisms at Membranes
Authors: Johnson Arthur E.
Published: September 2005

Processes that occur at membranes are essential for the viability of every cell, but such processes are the least well understood at the molecular level. The complex nature and physical properties of the molecular components involved, as well as the requirement for two separated aqueous compartments, restrict the experimental approaches that can be successfully applied to examine the structure, conformational changes and interactions of the membrane‐bound proteins that accomplish these processes. In particular, to accurately elucidate the molecular mechanisms that effect and regulate such processes, one must use experimental approaches that do not disrupt the structural integrity or functionality of the protein–membrane complexes being examined. To best accomplish this goal, especially when large multicomponent complexes and native membranes are involved, the optimal experimental approach to use is most often fluorescence spectroscopy. Using multiple independent fluorescence techniques, one can determine structural information in real time and in intact membranes under native conditions that cannot be obtained by crystallography, electron microscopy and NMR techniques, among others. Furthermore, fluorescence techniques provide a comprehensive range of information, from kinetic to thermodynamic, about the assembly, structure, function and regulation of membrane‐bound proteins and complexes. This article describes the use of various fluorescence techniques to characterize different aspects of proteins bound to or embedded in membranes.
Kinaseinhibitoren zur Therapie des malignen Melanoms
Authors: Becker Jürgen C. , Schrama David , Bröcker Eva‐B. , Houben Roland
Published: September 2005

Die von der grundlagenwissenschaftlichen und translationalen Forschung erarbeiteten Erkenntnisse über die Ursachen und Mechanismen der Melanomentstehung und ‐progression werden sich in den nächsten Jahren auf die Therapie auswirken. Die zunehmende Aufklärung der molekularen Pathogenese maligner Erkrankungen und die differenzierte Analyse der verschiedenen Signal‐ und Regulationswege innerhalb und außerhalb der malignen Zelle führte zu neuen, relativ spezifischen Ansatzpunkten, um in den malignen Prozess einzugreifen. Diese Interventionen zielen auf einzelne Moleküle ab, welche mit der malignen Grunderkrankung assoziiert sind oder sie sogar induzieren, weshalb diese Interventionen auch als „targeted therapy” bezeichnet werden. Diese Arbeit gibt eine kurze Übersicht über therapeutische Möglichkeiten, welche auf einer Modulation der Ras/MAPK‐ und des PI3K/AKT‐Signaltransduktionsweges abzielen.
P‐Glycoprotein is localized in intermediate‐density membrane microdomains distinct from classical lipid rafts and caveolar domains
Authors: Radeva Galina , Perabo Jocelyne , Sharom Frances J.
Published: September 2005

P‐glycoprotein (Pgp), a member of the ATP‐binding cassette (ABC) superfamily responsible for the ATP‐driven extrusion of diverse hydrophobic molecules from cells, is a cause of multidrug resistance in human tumours. Pgp can also operate as a phospholipid and glycosphingolipid flippase, and has been functionally linked to cholesterol, suggesting that it might be associated with sphingolipid–cholesterol microdomains in cell membranes. We have used nonionic detergent extraction and density gradient centrifugation of extracts from the multidrug‐resistant Chinese hamster ovary cell line, CHRB30, to address this question. Our data indicate that Pgp is localized in intermediate‐density membrane microdomains different from classical lipid rafts enriched in Src‐family kinases. We demonstrate that Brij‐96 can selectively isolate the Pgp domains, separating them from the caveolar and classical lipid rafts. Pgp was found entirely in the Brij‐96‐insoluble domains, and only partially in the Triton X‐100‐insoluble membrane microdomains. We studied the sensitivity of these domains to cholesterol removal, as well as their relationship to GM1 ganglioside‐ and caveolin‐1‐enriched caveolar domains. We found that the buoyant density of the Brij‐96‐based Pgp‐containing microdomains was sensitive to cholesterol removal by methyl‐β‐cyclodextrin. The Brij‐96 domains retained their structural integrity after cholesterol depletion while, in contrast, the Triton X‐100‐based caveolin‐1/GM1 microdomains did not. Using confocal fluorescence microscopy, we determined that caveolin‐1 and GM1 colocalized, while Pgp and caveolin‐1, or Pgp and GM1, did not. Our results suggest that Pgp does not interact directly with caveolin‐1, and is localized in intermediate‐density domains, distinct from classical lipid rafts and caveolae, which can be isolated using Brij‐96.
MMP‐7 promoter polymorphisms do not influence CD4+ recovery and changes in plasma viral load during antiretroviral therapy for HIV‐1 infection
Authors: Lugli E. , Pinti M. , Nasi M. , Troiano L. , Prada N. , Mussini C. , Borghi V. , Esposito R. , Cossarizza A.
Published: September 2005

Matrix metalloproteinase‐7 (MMP‐7) generates soluble Fas Ligand (FasL), which is involved in the apoptotic loss of CD4+ T cells during HIV infection. We evaluated whether two polymorphisms in MMP‐7 promoter could influence CD4+ recover in response to antiretroviral therapy, and found that these polymorphisms are ineffective.
Sodium pump α2 subunits control myogenic tone and blood pressure in mice
Authors: Zhang Jin , Lee Moo Yeol , Cavalli Maurizio , Chen Ling , Berra‐Romani Roberto , Balke C. William , Bianchi Giuseppe , Ferrari Patrizia , Hamlyn John M. , Iwamoto Takahiro , Lingrel Jerry B. , Matteson Donald R. , Wier W. Gil , Blaustein Mordecai P.
Published: September 2005

A key question in hypertension is: How is long‐term blood pressure controlled? A clue is that chronic salt retention elevates an endogenous ouabain‐like compound (EOLC) and induces salt‐dependent hypertension mediated by Na+/Ca2+ exchange (NCX). The precise mechanism, however, is unresolved. Here we study blood pressure and isolated small arteries of mice with reduced expression of Na+ pump α1 (α1+/−) or α2 (α2+/−) catalytic subunits. Both low‐dose ouabain (1–100 nm; inhibits only α2) and high‐dose ouabain (≥1 μm; inhibits α1) elevate myocyte Ca2+ and constrict arteries from α1+/−, as well as α2+/− and wild‐type mice. Nevertheless, only mice with reduced α2 Na+ pump activity (α2+/−), and not α1 (α1+/−), have elevated blood pressure. Also, isolated, pressurized arteries from α2+/−, but not α1+/−, have increased myogenic tone. Ouabain antagonists (PST 2238 and canrenone) and NCX blockers (SEA0400 and KB‐R7943) normalize myogenic tone in ouabain‐treated arteries. Only the NCX blockers normalize the elevated myogenic tone in α2+/− arteries because this tone is ouabain independent. All four agents are known to lower blood pressure in salt‐dependent and ouabain‐induced hypertension. Thus, chronically reduced α2 activity (α2+/− or chronic ouabain) apparently regulates myogenic tone and long‐term blood pressure whereas reduced α1 activity (α1+/−) plays no persistent role: the in vivo changes in blood pressure reflect the in vitro changes in myogenic tone. Accordingly, in salt‐dependent hypertension, EOLC probably increases vascular resistance and blood pressure by reducing α2 Na+ pump activity and promoting Ca2+ entry via NCX in myocytes.
A direct relationship between plasma aldosterone and cardiac L‐type Ca2+ current in mice
Authors: Perrier Romain , Richard Sylvain , Sainte‐Marie Yannis , Rossier Bernard C. , Jaisser Frederic , Hummler Edith , Bénitah Jean‐Pierre
Published: September 2005

Aldosterone is involved in a variety of pathophysiological processes that ultimately cause cardiovascular diseases. Despite this, the physiological role of aldosterone in heart function remains elusive. We took advantage of transgenic mouse models characterized by a renal salt‐losing (SL) or salt‐retaining (SR) phenotype, thus exhibiting chronically high or low plasma aldosterone levels, respectively, to investigate the chronic effects of aldosterone in cardiomyocytes devoid of pathology. On a diet containing normal levels of salt, these animals do not develop any evidence of cardiovascular disease. Using the whole cell patch‐clamp technique on freshly isolated adult ventricular cardiomyocytes, we observed that the amplitude of L‐type Ca2+ currents (ICa) correlates with plasma aldosterone levels. Larger values of ICa are associated with high aldosterone concentrations in SL models, whereas smaller values of ICa were observed in the SR model. Neither the time‐ nor the voltage‐dependent properties of ICa varied measurably. In parallel, we determined whether modulation of ICa by blood concentration of aldosterone has a major physiological impact on the excitation–contraction coupling of the cardiomyocytes. Action potential duration, [Ca2+]i transient amplitude and contraction are increased in the SL model and decreased in the SR model. In conclusion, we demonstrate that the blood concentration of aldosterone exerts chronic regulation of ICa in mouse cardiomyocytes. This regulation has important consequences for excitation–contraction coupling and, potentially, for other Ca2+‐regulated functions in cardiomyocytes.
Allosteric interaction between zinc and glutamate binding domains on NR2A causes desensitization of NMDA receptors
Authors: Erreger Kevin , Traynelis Stephen F.
Published: September 2005

Fast desensitization is an important regulatory mechanism of neuronal NMDA receptor function. Previous work suggests that fast desensitization of NR1/NR2A receptors is caused by ambient zinc, and that a positive allosteric interaction occurs between the extracellular zinc‐binding amino terminal domain and the glutamate‐binding domain of NR2A. The relaxation of macroscopic currents in the presence of zinc reflects a shift to a new equilibrium due to increased zinc affinity following the binding of glutamate. Here we demonstrate that this allosteric coupling reflects interactions within the NR2A subunit, and that the affinity of zinc for its binding site is regulated by glutamate binding and not by glycine binding nor by channel pore opening. We fit an explicit model to experimental data over a wide range of parameters, demonstrating that allosteric theory can quantitatively account for the fast zinc‐dependent component of desensitization for NR1/NR2A NMDA receptors. We subsequently use this model to evaluate the effects of extracellular zinc on NR1/NR2A excitatory postsynaptic currents (EPSCs) by simulating the response to a brief synaptic‐like pulse of glutamate. Modelling results show that zinc at a steady‐state concentration of at least 100 nm has a significant effect on the amplitude of NMDA EPSCs but that concurrent release of 10 μm zinc with synaptic glutamate release has little effect on the amplitude of a single NR1/NR2A NMDA EPSC. These data suggest that while steady‐state zinc can regulate the amplitude of synaptic NMDA currents, zinc co‐released with glutamate will only have significant impact under conditions of high frequency activity or at concentrations high enough to cause voltage‐dependent channel block.
Contrasting short‐term plasticity at two sides of the mitral–granule reciprocal synapse in the mammalian olfactory bulb
Authors: Dietz Shelby B. , Murthy Venkatesh N.
Published: September 2005

The mitral–granule reciprocal synapse shapes the response of the olfactory bulb to odour stimuli by mediating lateral and reciprocal inhibition. We investigated the short‐term plasticity of both the mitral‐to‐granule excitatory synapse and the granule‐to‐mitral inhibitory synapse in rat olfactory bulb slices, using whole‐cell patch clamp recordings. The granule‐to‐mitral inhibitory synapse invariably exhibited paired‐pulse depression at interstimulus intervals of less than a second, while the mitral‐to‐granule excitatory synapse showed heterogeneous responses, which on average yielded a moderate facilitation. Trains of stimuli led to a much greater depression at the granule‐to‐mitral synapse than at the mitral‐to‐granule synapse. Since mitral cells commonly respond to odours by burst firing with each inhalation cycle, we used bursts of stimuli to study recovery from depression. We found that recovery from depression induced by fast trains of stimuli was more rapid at the mitral‐to‐granule synapse than at the granule‐to‐mitral synapse. In addition, depression was enhanced by higher calcium concentrations, suggesting at least partial contribution of presynaptic mechanisms to short‐term depression. The observed short‐term plasticity could enable mitral cells to overcome autoinhibition and increase action potential propagation along lateral dendrites by burst firing.
Rolling motion of non-axisymmetric cylinders
Authors: Carnevali Antonino , May Russell
Published: September 2005

Theoretical and experimental results are compared for the rolling motion of cylinders on a ramp. An asymmetric distribution of the mass makes the motion jerky and complex and is an interesting and simple example of Lagrangian mechanics.
Bounce of a spinning ball near normal incidence
Authors: Cross Rod
Published: September 2005

A spinning ball incident at right angles to a surface bounces at an oblique angle and with reduced spin. Consequently, a spinning ball struck head-on does not rebound along its incident path, which presents a control problem in bat and racquet sports. The rebound angle and spin depend in a nontrivial manner on the coefficient of friction between the ball and the surface and on the elastic properties of the ball and the surface. Values of the normal and tangential coefficients of restitution coefficients are presented for a tennis ball impacting a smooth and a rough surface and on strings of a tennis racquet. The implications for spin generation in tennis are briefly described.
Symplectic integrators: An introduction
Authors: Donnelly Denis , Rogers Edwin
Published: September 2005

Symplectic integrators very nearly conserve the total energy and are particularly useful when treating long times. We demonstrate some of the properties of these integrators by exploring the structure of first-, second-, and fourth-order symplectic integrators and apply them to the simple harmonic oscillator. We consider numeric, geometric, and analytic aspects of the integrators with particular attention to the computed energies.
Job constraints and arterial hypertension: different effects in men and women: the IHPAF II case control study
Authors: Radi S , Lang T , Lauwers-Cancès V , Diène E , Chatellier G , Larabi L , De Gaudemaris R
Published: September 2005

Aims:To examine, in a working population of men and women, the relation between organisational job constraints (job strain, passive and active jobs) and incident hypertension and the buffering effect of social support at work on this relation.

Methods:A nested case control study was designed within the IHPAF (Incidence of Hypertension in a French Working Population) cohort study. The 20 worksite physicians participating in the study enrolled 203 cases and matched each case for age (SD 10 years) and sex with two normotensive subjects attending the follow up screening immediately after him or her. As a result, 426 men and 183 women were included in the study.

Results:Mean age was 41.8 (SD 7.8) years in men and 43.5 (SD 7.5) years in women. Relations between job constraints and hypertension were stronger in women than in men. Odds ratios (OR) were 3.20 (95% CI 0.92 to 11.12) in women and 2.60 (95% CI 1.15 to 5.85) in men for job strain, 4.73 (95% CI 1.36 to 16.42) in women and 2.30 (95% CI 1.01 to 5.26) in men for passive jobs, and 4.51 (95% CI 1.24 to 16.43) in women and 2.39 (95% CI 1.10 to 5.18) in men for active jobs. Low social support at work was not related to hypertension and did not decrease the association with organisational risk factors. In both hypertensive men and women, obesity was related to hypertension (OR = 13.20 (95% CI 3.34 to 52.14) in women and 6.54 (95% CI 2.99 to 14.29) in men) and the prevalence of recent stressful life events was significantly lower in hypertensive women (OR = 0.32 (95% CI 0.12 to 0.89)) and men (OR = 0.37 (95% CI 0.20 to 0.67) compared with normotensives. Alcohol consumption was a significant risk factor for hypertension in women (OR = 3.47 (95% CI 1.18 to 10.25)).

Conclusion:A stronger relation between job constraints and hypertension was observed in women compared with men. These findings emphasise the need of addressing more sex-specific concepts of work related stress on the one hand, and of understanding the direct and indirect mechanisms linking psychosocial factors and hypertension in both sexes on the other hand.
Is metal fume fever a determinant of welding related respiratory symptoms and/or increased bronchial responsiveness? A longitudinal study
Authors: El-Zein M , Infante-Rivard C , Malo J-L , Gautrin D
Published: September 2005

Background:The current prospective study investigated the hypothesis of metal fume fever (MFF) being a predictor for the development of respiratory symptoms and functional abnormalities.

Methods:The study consisted of a pre-exposure and two follow up assessments of 286 welding apprentices during an average period of 15 months. A respiratory and a systemic symptom questionnaire, skin prick tests to common allergens and metal salts, spirometry, and methacholine challenge tests were administered.

Results:Developing at least one positive skin prick test to a metallic salt solution was found in 11.8% of apprentices. Possible MFF (at least one of fever, feelings of flu, general malaise, chills, dry cough, metallic taste, or shortness of breath) was reported by 39.2% of apprentices. The presence of at least one welding related respiratory symptom (cough, wheezing, or chest tightness) suggestive of welding related asthma was reported by 13.8%. MFF was significantly associated with these respiratory symptoms (OR = 4.92, 95% CI 2.10 to 11.52), after adjusting for age, atopy, smoking, physician diagnosed asthma, and symptoms of non-welding related asthma. Apprentices with possible MFF, and no welding related respiratory symptoms suggestive of welding related asthma at the first follow up, had an increased risk of developing the latter symptoms by the second follow up visit (OR = 7.4, 95% CI 1.97 to 27.45) compared with those not having MFF. MFF was not significantly associated with an increase in bronchial responsiveness.

Conclusion:MFF could be a predictor for the development of respiratory symptoms but not for functional abnormalities in welders.
Rapidly progressive coal workers’ pneumoconiosis in the United States: geographic clustering and other factors
Authors: dos S Antao V C , Petsonk E L , Sokolow L Z , Wolfe A L , Pinheiro G A , Hale J M , Attfield M D
Published: September 2005

Background:Despite significant progress made in reducing dust exposures in underground coal miners in the United States, severe cases of coal workers’ pneumoconiosis (CWP), including progressive massive fibrosis (PMF), continue to occur among coal miners.

Aims:To identify US miners with rapidly progressive CWP and to describe their geographic distribution and associated risk factors.

Methods:Radiographic evidence of disease progression was evaluated for underground coal miners examined through US federal chest radiograph surveillance programmes from 1996 to 2002. A case of rapidly progressive CWP was defined as the development of PMF and/or an increase in small opacity profusion greater than one subcategory over five years. County based prevalences were derived for both CWP and rapidly progressive cases.

Results:A total of 886 cases of CWP were identified among 29 521 miners examined from 1996 to 2002. Among the subset of 783 miners with CWP for whom progression could be evaluated, 277 (35.4%) were cases of rapidly progressive CWP, including 41 with PMF. Miners with rapidly progressive CWP were younger than miners without rapid progression, were more likely to have worked in smaller mines (<50 employees), and also reported longer mean tenure in jobs involving work at the face of the mine (in contrast to other underground mining jobs), but did not differ with respect to mean underground tenure. There was a clear tendency for the proportion of cases of rapidly progressive CWP to be higher in eastern Kentucky, and western Virginia.

Conclusions:Cases of rapidly progressive CWP can be regarded as sentinel health events, indicating inadequate prevention measures in specific regions. Such events should prompt investigations to identify causal factors and initiate appropriate additional measures to prevent further disease.
INDIVIDUAL ENTREPRENEURIAL CHARACTERISTICS AND ENTREPRENEURIAL SUCCESS POTENTIAL
Authors: WONG WING-KI , CHEUNG HONG-MAN , VENUVINOD PATRI K.
Published: September 2005

Entrepreneurial technology-based new venture constitutes a dominant proportion of incubated firms. Often, such firms are established by engineering graduates. This paper investigates a methodology for assessing the potential for success of new ventures set up at an early stage by engineering students via an evaluation of the entrepreneurial personalities of engineering students. The survey of 215 students of Manufacturing Engineering indicates particular traits have a strong predictive impact on the proclivity towards the different 'idea factors on innovation' suggested by Goldenberg et al. [1999]. In particular, 'risk-taking propensity' and 'need to achieve' are two critical characteristics that significantly influence the selection of 'success-intended' idea factors whereas 'external locus of control' influences the selection of 'failure-intended' idea factors. The findings have important implications for researchers, business incubators, and policy makers inside and outside universities. Based on the extensive literature and successful result in demonstrating entrepreneurial characteristics as predictors of sustainable competitive advantage of future entrepreneurs by identifying types of idea factor adopter, the results of this study can be used either as a self-evaluation (self-screening) before starting a new venture that has a higher success probability. Specifically, the results indicate that the classification of idea factor adopters, in terms of entrepreneurial behavior, the incubator may be better able to identify the go or no-go decision for applicants. For instance, incubators could try to base their selection process for business incubation programme partly on information provided by applicants about personality traits and preferences regarding entrepreneurship.
IMPLICATIONS OF TECHNOLOGICAL CONVERGENCE ON INNOVATION TRAJECTORIES: THE CASE OF ICT INDUSTRY
Authors: HACKLIN FREDRIK , RAURICH VICENTE , MARXT CHRISTIAN
Published: September 2005

Current innovation management literature and research statically differentiates between incremental and disruptive innovation, as far as the trajectory development is concerned. Incremental innovation is generally comprehended as an improvement of technology performance or product feature enhancement, whereas disruptive innovation is defined based on technologies previously new to the world, combined with their effects on markets. The authors of this research present how a convergence of several well-known, incrementally developing technologies can result in innovations with highly disruptive character in terms of innovation trajectories. Paradoxically, in disruptive situations, operative actions must be taken before strategic planning can be made, as the industrial and economic environment can be regarded as extremely uncertain. In this context, however, we argue that this special case caused by the convergence of technologies can serve to understand certain areas of emerging industrial disruptions and hence support the strategic planning and technology management of a firm acting in this area. The case of information and communication technology (ICT) industry is used to highlight this convergence phenomenon as a special case of emerging disruptive innovation. Based on this example, the process of innovations transforming from incremental towards disruptive due to convergence will be examined, and entrepreneurial recommendations for sustaining the competitive advantage and supporting value creation will be derived.
HOW TO USE ANALOGIES FOR BREAKTHROUGH INNOVATIONS
Authors: HERSTATT CORNELIUS , KALOGERAKIS KATHARINA
Published: September 2005

Analogies can trigger breakthrough ideas in new product development. Numerous examples demonstrate that substantial innovations often result from transferring problem solutions from one industry or domain to another. For instance, the designers of the new running show generation of Nike, "Nike SHOX", use the same suspension concept like the technologies applied for formula 1 racing cars, or the biological Lotus-effect leading to the evelopment of various self-cleaning surfaces. Academic research on analogical thinking has been so far heavily influenced by general theoretical work from cognitive psychology or systematic inventing. Only a small number of studies have investigated the application of analogies in the specific context of breakthrough innovation projects. This paper focuses on the question on how analogies can be systematically used in the early innovation phases of new product development and which factors influence the successful use of analogical thinking in innovating companies. Special attention is paid to organizational facilitators and the requests on people involved in this process.
USING ANT AGENTS TO COMBINE REACTIVE AND PROACTIVE STRATEGIES FOR ROUTING IN MOBILE AD-HOC NETWORKS
Authors: DUCATELLE FREDERICK , DI CARO GIANNI , GAMBARDELLA LUCA MARIA
Published: September 2005

This paper describes AntHocNet, an algorithm for routing in mobile ad-hoc networks based on ideas from the ant colony optimisation framework. In AntHocNet a source node reactively sets up a path to a destination node at the start of each communication session. During the course of the session, the source node uses ant agents to proactively search for alternatives and improvements of the original path. This allows to adapt to changes in the network, and to construct a mesh of alternative paths between source and destination. The proactive behaviour is supported by a lightweight information bootstrapping process. Paths are represented in the form of distance-vector routing tables called pheromone tables. An entry of a pheromone table contains the estimated goodness of going over a certain neighbour to reach a certain destination. Data are routed stochastically over the different paths of the mesh according to these goodness estimates. In an extensive set of simulation tests, we compare AntHocNet to AODV, a reactive algorithm which is an important reference in this research area. We show that AntHocNet can outperform AODV for different evaluation criteria in a wide range of different scenarios. AntHocNet is also shown to scale well with respect to the number of nodes.
RELIABLE COMMUNICATION NETWORK DESIGN WITH EVOLUTIONARY ALGORITHMS
Authors: REICHELT DIRK , ROTHLAUF FRANZ
Published: September 2005

For the reliable communication network design (RCND) problem unreliable links are available, each bearing several options which have different levels of reliability and varying costs. The goal is to find the most cost-effective communication network design that satisfies a predefined overall reliability constraint. This paper presents two new evolutionary algorithm (EA) approaches to solving the RCND problem: LaBORNet and BaBORNet. LaBORNet uses an encoding that represents the network topology as well as the used link options while repairing infeasible solutions using an additional repair heuristic (CURE). BaBORNet encodes only the network topology and determines the link options by using the repair heuristic CURE as a local search method. The experimental results show that the new EA approaches using repair heuristics outperform existing EA approaches from the literature using penalties for infeasible solutions. They also find better solutions for existing problems from the literature, as well as for new and larger test problems.
COMPARISONS: Possible and Impossible
Authors: Moore Sally Falk
Published: September 2005

In the twentieth century, many anthropological comparisons were mounted on the base of the synchronic societal ethnographies being produced at the time. That work produced a valuable inventory of the range of variations and differences. Now, following quite a different track, and defining the task anew, a remarkable number of ethnographies consist of observations of processes of change as they go along. The considerable obstacles to comparing such temporally oriented, processual case histories distinguishes them from earlier studies of tradition and custom. In this review, five abbreviated case histories of ongoing development projects illustrate the difference of approach. The process by which plans to control particular aspects of a social field are designed, implemented, altered, and diverted are the object of these ethnographic studies. The cultures of control employed by the planners are noted, but the dynamic of the societal context into which projects are introduced is shown to be equally important to the outcome. No less than a redefinition of the anthropological field of observation is involved in this approach.
WILL INDIGENOUS LANGUAGES SURVIVE?
Authors: Walsh Michael
Published: September 2005

Much attention has been focused on the survival of Indigenous languages in recent years. Many, particularly anthropologists and linguists, anticipate the demise of the majority of Indigenous languages within this century and have called on the need to arrest the loss of languages. Opinions vary concerning the loss of language; some regard it as a hopeless cause, and others see language revitalization as a major responsibility of linguistics and kindred disciplines. To that end, this review explores efforts in language revitalization and documentation and the engagement with Indigenous peoples. It remains unclear why some attempts at language revitalization succeed, whereas others fail. What is clear is that the process is profoundly political.
Insects on Plants: Diversity of Herbivore Assemblages Revisited
Authors: Lewinsohn Thomas M. , Novotny Vojtech , Basset Yves
Published: September 2005

▪ Abstract  The diversity and composition of herbivore assemblages was a favored theme for community ecology in the 1970s and culminated in 1984 with Insects on Plants by Strong, Lawton and Southwood. We scrutinize findings since then, considering analyses of country-wide insect-host catalogs, field studies of local herbivore communities, and comparative studies at different spatial scales. Studies in tropical forests have advanced significantly and offer new insights into stratification and host specialization of herbivores. Comparative and long-term data sets are still scarce, which limits assessment of general patterns in herbivore richness and assemblage structure. Methods of community phylogenetic analysis, complex networks, spatial and among-host diversity partitioning, and metacommunity models represent promising approaches for future work.
Hepatic pharmacokinetics of propranolol in rats with adjuvant-induced systemic inflammation
Authors: Hung Daniel Y. , Siebert Gerhard A. , Chang Ping , Whitehouse Michael W. , Fletcher Linda , Crawford Darrell H. G. , Roberts Michael S.
Published: September 2005

Systemic inflammation is known to affect drug disposition in the liver. This study sought to relate and quantitate changes in hepatic pharmacokinetics of propranolol with changes in hepatic architecture and physiology in adjuvant-treated rats. Transmission electron microscopy was used to assess morphological changes in mitochondria and lysosomes of adjuvant-treated rat livers. The disposition of propranolol was assessed in the perfused rat liver using the multiple indicator dilution technique. Hepatic extraction and mean transit time were determined from outflow-concentration profiles using a nonparametric method. Kinetic parameters were derived from a two-phase physiologically based organ pharmacokinetic model. Possible relationships were then explored between the changes in hepatic drug disposition and cytochrome P-450 activity and iron concentration. Adjuvant treatment induced the appearance of mitochondrial inclusions/tubularization and irregularly shaped lysosomes in rat livers. Livers from adjuvant-treated rats had (relative to normal) significantly higher α1-acid glycoprotein (orosomucoid) and iron tissue concentrations but lower cytochrome P-450 content. The hepatic extraction, metabolism, and ion trapping of propranolol were significantly impaired in adjuvant-treated rats and could be correlated with altered iron store and cytochrome P-450 activity. It is concluded that adjuvant-induced systemic inflammation alters hepatocellular morphology and biochemistry and consequently influences hepatic disposition of propranolol.