bluuebunny/crossref_metadata_2025 huggingface dataset:
Trajectories of Internationalization: Knowledge and National Business Styles in the Making of Two Dutch Publishing Multinationals, 1950–1990
Authors: Lente Dick Van , Goey Ferry De
Published: December 2007

The internationalization of business is the subject of an extensive theoretical literature as well as a growing number of historical studies. Historians have paid relatively little attention to the development of multinationals in the service sector, and studies about international publishing are especially scarce. This article discusses the early internationalization of two Dutch publishing firms, Kluwer (nowWolters Kluwer) and Elsevier (now Reed Elsevier) and confronts these case histories with the evolutionary theory of internationalization. The Dutch cases underline the important role of experience, knowledge and learning as well as of the national context in which companies develop. They also show that these factors allow for very different trajectories of internationalization within the same branch of business and the same country.
Genetic Dissection of Resistance to Anthracnose and Powdery Mildew in Medicago truncatula
Authors: Ameline-Torregrosa Carine , Cazaux Marc , Danesh Dariush , Chardon Fabien , Cannon Steven B. , Esquerré-Tugayé Marie-Thérèse , Dumas Bernard , Young Nevin D. , Samac Deborah A. , Huguet Thierry , Jacquet Christophe
Published: December 2007

Medicago truncatula was used to characterize resistance to anthracnose and powdery mildew caused by Colletotrichum trifolii and Erysiphe pisi, respectively. Two isolates of E. pisi (Ep-p from pea and Ep-a from alfalfa) and two races of C. trifolii (races 1 and 2) were used in this study. The A17 genotype was resistant and displayed a hypersensitive response after inoculation with either pathogen, while lines F83005.5 and DZA315.16 were susceptible to anthracnose and powdery mildew, respectively. To identify the genetic determinants underlying resistance in A17, two F7 recombinant inbred line (RIL) populations, LR4 (A17 × DZA315.16) and LR5 (A17 × F83005.5), were phenotyped with E. pisi isolates and C. trifolii races, respectively. Genetic analyses showed that i) resistance to anthracnose is governed mainly by a single major locus to both races, named Ct1 and located on the upper part of chromosome 4; and ii) resistance to powdery mildew involves three distinct loci, Epp1 on chromosome 4 and Epa1 and Epa2 on chromosome 5. The use of a consensus genetic map for the two RIL populations revealed that Ct1 and Epp1, although located in the same genome region, were clearly distinct. In silico analysis in this region identified the presence of several clusters of nucleotide binding site leucine-rich repeat genes. Many of these genes have atypical resistance gene analog structures and display differential expression patterns in distinct stress-related cDNA libraries.
Ubc2, an Ortholog of the Yeast Ste50p Adaptor, Possesses a Basidiomycete-Specific Carboxy Terminal Extension Essential for Pathogenicity Independent of Pheromone Response
Authors: Klosterman Steven J. , Martinez-Espinoza Alfredo D. , Andrews David L. , Seay Jeffrey R. , Gold Scott E.
Published: December 2007

Proteins involved in the mitogen-activated protein (MAP) kinase pathway controlling mating, morphogenesis, and pathogenicity have been identified previously in the fungus Ustilago maydis. One of these, the Ubc2 adaptor protein, possesses a basidiomycete-specific structure. In addition to containing sterile α motif (SAM) and ras association (RA) domains typical of Ste50-like adaptor proteins found in the fungal phylum Ascomycota, Ubc2 also contains two C-terminal SH3 domains. Yeast two-hybrid assays indicated that Ubc2 interacts with the MAP kinase-kinase kinase Ubc4 via the SAM domains at each of their respective N-termini. Site-directed mutagenesis of ubc2 and complementation analyses revealed that the SAM and RA domains of Ubc2 are essential for filamentous growth. These data support a role for the ascomycete-like N-terminus of Ubc2 in regulating pheromone-responsive mating and morphogenesis analogous to the role of Ste50p in Saccharomyces cerevisiae. In contrast, C-terminal deletion mutants were fully capable of filamentous growth and mating. However, surprisingly, these strains were nonpathogenic. Further, directed mutagenesis of the C-terminus revealed that both SH3 domains are required for pathogenicity. These results suggest that the Basidiomycota have retained the mating and morphogenetic functions of Ste50-type proteins in the N-terminal half of their Ubc2-type adaptors but, additionally, have integrated C-terminal SH3 domains that are critical for additional signal transduction mechanisms, including those that lead to pathogenesis.
Dynamic Regulation of GacA in Type III Secretion, Pectinase Gene Expression, Pellicle Formation, and Pathogenicity of Dickeya dadantii (Erwinia chrysanthemi 3937)
Authors: Yang Shihui , Peng Quan , Zhang Qiu , Yi Xuan , Choi Chang Jae , Reedy Ralph M. , Charkowski Amy O. , Yang Ching-Hong
Published: December 2007

Dickeya dadantii (Erwinia chrysanthemi 3937) secretes exoenzymes, including pectin-degrading enzymes, leading to the loss of structural integrity of plant cell walls. A type III secretion system (T3SS) is essential for full virulence of this bacterium within plant hosts. The GacS/GacA two-component signal transduction system participates in important biological roles in several gram-negative bacteria. In this study, a gacA deletion mutant (Ech137) of D. dadantii was constructed to investigate the effect of this mutation on pathogenesis and other phenotypes. Compared with wild-type D. dadantii, Ech137 had a delayed biofilm-pellicle formation. The production of pectate lyase (Pel), protease, and cellulase was diminished in Ech137 compared with the wild-type cells. Reduced transcription of two endo-Pel genes, pelD and pelL, was found in Ech137 using a green fluorescence protein-based fluorescence-activated cell sorter promoter activity assay. In addition, the transcription of T3SS genes dspE (an effector), hrpA (a structural protein of the T3SS pilus), and hrpN (a T3SS harpin) was reduced in Ech137. A lower amount of rsmB regulatory RNA was found in gacA mutant Ech137 compared with the wild-type bacterium by quantitative reverse-transcription polymerase chain reaction. Compared with wild-type D. dadantii, a lower amount of hrpL mRNA was observed in Ech137 at 12 h grown in medium. Although the role of RsmA, rsmB, and RsmC in D. dadantii is not clear, from the regulatory pathway revealed in E. carotovora, the lower expression of dspE, hrpA, and hrpN in Ech137 may be due to a posttranscriptional regulation of hrpL through the Gac-Rsm regulatory pathway. Consequently, the reduced exoenzyme production and Pel gene expression in the mutant may be partially due to the regulatory role of rsmB-RsmA on exoenzyme expression. Similar to in vitro results, a lower expression of T3SS and pectinase genes of Ech137 also was observed in bacterial cells inoculated into Saintpaulia ionantha leaves, perhaps accounting for the observed reduction in local maceration. Interestingly, compared with the wild-type D. dadantii, although a lower concentration of Ech137 was observed at day 3 and 4 postinoculation, there is no significant difference in bacterial concentration between the wild-type bacterium and Ech137 in the early stage of infection. Finally, the nearly abolished systemic invasion ability of Ech137 suggests that GacA of D. dadantii is essential for the pathogenicity and systemic movement of the bacterium in S. ionantha.
Maxwell's far-field methodology applied to the prediction of properties of multi-phase isotropic particulate composites
Authors: McCartney L. Neil , Kelly Anthony
Published: December 2007

The far-field methodology developed by Maxwell, when estimating the effective electrical conductivity of isotropic particulate composites, is used to estimate effective thermoelastic properties of multi-phase isotropic composites. In particular, Maxwell's methodology applied to the analogous thermal conduction problem is described, extending the approach to multi-phase spherical particles having different sizes and properties. The methodology is also used to estimate the effective bulk and shear moduli, and the thermal expansion coefficients, of multi-phase isotropic particulate composites. Results correspond with expressions derived in the literature, and coincide with, or lie between, variational bounds for all volume fractions. These characteristics, relating to isotropic effective properties, indicate that results obtained using the methodology, are not necessarily restricted to low volume fractions, as originally suggested by Maxwell. It is concluded that Maxwell's methodology is a unifying optimum technique to estimate the properties of multi-phase isotropic particulate composites, because it provides closed form estimates that are fully consistent with other methods, without imposing restrictions, except that the particles must be spherical (but can have a range of size and properties) and the resultant effective properties must be isotropic.
Poroelastic acoustic wave trains excited by harmonic line tractions
Authors: Gerasik Vladimir , Stastna Marek
Published: December 2007

A two-dimensional boundary-value problem for a porous half-space with an open boundary, described by the widely recognized Biot's equations of poroelasticity, is considered. Using complex analysis techniques, a general solution is represented as a superposition of contributions from the four different types of motion corresponding to P1, P2, S and Rayleigh waves. Far-field asymptotic solutions for the bulk modes, as well as near-field numerical results, are investigated. Most notably, this analysis reveals the following: (i) a line traction generates three wave trains corresponding to the bulk modes, so that P1, P2 and S modes emerge from corresponding wave trains at a certain distance from the source, (ii) bulk modes propagating along the plane boundary are subjected to geometric attenuation, which is found quantitatively to bex−3/2, similar to the classical results in perfect elasticity theory, (iii) the Rayleigh wave is found to be predominant at the surface in both the near (due to the negation of the P1 and S wave trains) and the far field (due to geometric attenuation of the bulk modes), and (iv) the recovery of the transition to the classical perfect elasticity asymptotic results validates the asymptotics established herein.
Carotenoid trade-off between parasitic resistance and sexual display: an experimental study in the blackbird (
Turdus merula
)
Authors: Baeta R , Faivre B , Motreuil S , Gaillard M , Moreau J
Published: December 2007

Many parasites depress the expression of the carotenoid-based colour displays of their hosts, and it has been hypothesized that animals face a trade-off in carotenoid allocation between immune functions and ‘degree of ornamentation’. While numerous correlative studies suggest that parasite infection decreases the intensity of carotenoid-based colour displays, the existence of this trade-off has never been demonstrated experimentally in a host–parasite model. In this study, we used the blackbird (
Turdus merula
) and
Isospora
(an intestinal parasite) to assess whether this trade-off does indeed exist. Blackbirds were supplemented with carotenoids while simultaneously being exposed to parasites. Supplemented males circulated more carotenoids in the blood and developed more brightly coloured bills than unsupplemented males. In addition, supplementation slowed down the replication rate of parasites. Supplementation with carotenoids enabled infected birds to maintain their bill coloration, whereas birds that were infected but not supplemented showed reduced bill coloration. At the same time, infection slowed carotenoid assimilation in the blood. Overall, we demonstrated that bill colour reflects a bird's health, and that only males with a carotenoid-rich diet are capable of coping with costs associated with parasitic infection. Carotenoids are thus traded off between host physiological response to parasites and secondary sexual traits. Further investigations are required to determine the physiological mechanisms that govern this trade-off.
Sexual and social stimuli elicit rapid and contrasting genomic responses
Authors: Cummings Molly E , Larkins-Ford Jonah , Reilly Christian R.L , Wong Ryan Y , Ramsey Mary , Hofmann Hans A
Published: December 2007

Sensory physiology has been shown to influence female mate choice, yet little is known about the mechanisms within the brain that regulate this critical behaviour. Here we examine preference behaviour of 58 female swordtails,
Xiphophorus nigrensis,
in four different social environments (attractive and unattractive males, females only, non-attractive males only and asocial conditions) followed by neural gene expression profiling. We used a brain-specific cDNA microarray to identify patterns of genomic response and candidate genes, followed by quantitative PCR (qPCR) examination of gene expression with variation in behaviour. Our microarray results revealed patterns of genomic response differing more between classes of social stimuli than between presence versus absence of stimuli. We identified suites of genes showing diametrically opposed patterns of expression: genes that are turned ‘on’ while females interact with attractive males are turned ‘off’ when interacting with other females, and vice versa. Our qPCR results identified significant predictive relationships between five candidate genes and specific mate choice behaviours (preference and receptivity) across females exposed to males, with no significant patterns identified in female or asocial conditions or with overall locomotor activity. The identification of stimulus- and behaviour-specific responses opens an exciting window into the molecular pathways associated with social behaviour and mechanisms that underlie sexual selection.
An Extension of the Trade Restrictiveness Index to Large Economies*
Authors: Dakhlia Sami , Temimi Akram
Published: December 2007

The Trade Restrictiveness Index (TRI) introduced by Anderson and Neary (1994) provided the first theoretically satisfying measure of a country’s tariff structure by overcoming the problem of ad hoc specification of indexing weights and the related index number problem. We observe, however, that the TRI may not exist or may not be unique when countries are large. As a remedy, we propose a simple extension.
Multilateralism and Hub‐and‐Spoke Bilateralism*
Authors: Mukunoki Hiroshi , Tachi Kentaro
Published: December 2007

This paper studies sequential negotiations of bilateral free‐trade agreements in an oligopoly model. The expansion of trading blocs through overlapping trade agreements allows the option of hub‐and‐spoke systems and achieves multilateral free trade as the equilibrium path, even if the expansion of trading blocs through the acceptance of new members is not feasible. The results suggest that free‐trade areas (FTAs) tend to expand more than customs unions (CUs). Lobbying by a producer can either promote or undermine the achievement of multilateral free trade through overlapping FTAs.
Passthrough Estimates and the Choice of an Exchange Rate Index*
Authors: Pollard Patricia S. , Coughlin Cletus C.
Published: December 2007

We examine exchange rate passthrough into US import prices for 29 manufacturing industries using eight exchange rate indexes. These indexes vary by the number of currencies included; whether the weight on each currency is based on total trade with the United States or solely imports; and, whether the weights vary by industry. Our results indicate that passthrough is generally incomplete but varies across industries. Moreover, passthrough is sensitive to the exchange rate index. Using bootstrapped J‐tests we show that major currency indexes perform better than their broad currency counterparts. When using a major currency index, industry‐specific exchange rate indexes are preferred to aggregate indexes.
Technology Transfer and Merger Activities with Trade and Tariffs
Authors: Ryan Cillian
Published: December 2007

In order to better understand the effects of globalization on merger incentives this paper considers a set of commonly observed mergers whereby a restructured target (with improved managerial or technical capability) continues to supply the market. In contrast to the market‐concentrating merger literature it finds that trade barriers tend to encourage mergers, including potentially welfare‐reducing, tariff‐jumping mergers. Multilateral trade liberalization, however, encourages welfare‐improving mergers. Hence, and despite the skepticism of regulatory authorities towards the existence of cost synergies as a consequence of mergers, this paper suggests that in order to assess the impact of trade liberalization under the WTO on merger incentives, and consequently on prices, quantities, and welfare, accurate information on ex ante cost differences and the transferability of managerial and technical techniques is required.
Heat Conduction in
Multilayered Rectangular Domains
Authors: Geer James , Desai Anand , Sammakia Bahgat
Published: December 2007

This paper presents the results of an analytical study of steady state heat conduction in multiple rectangular domains. Any finite number of domains that are equally sized (in plane) may be considered in the current analysis. The thermal conductivity and thickness of these domains may be different. The entire geometry composed of these connected domains is considered as adiabatic on the lateral surfaces and can be subjected to a wide range of thermal boundary conditions at the top and bottom. For example, the bottom of the stack may be adiabatic, while the top of the stack may be exposed to a uniform heat transfer coefficient. Spatially varying heat generation rates can be applied in each of the domains. The solutions are found to be in agreement with known solutions for simpler geometries. The analytical solution presented here is very general in that it takes into account the interface resistances between the layers. One application of this analytical study relates to the thermal management of three-dimensional stacks of computer devices and interconnect layers. The devices would have spatially nonuniform power dissipation within them, and the interconnect layers would have a significantly lower thermal conductivity than the devices. Interfacial defects, such as delamination or air voids, between the devices and the interconnect layers may be included in the model. Another possible application is to the study of hot spots in a chip stack with nonuniform heat generation. Many other potential applications may also be simulated.
A Systematic Approach
to Predicting Critical Heat Flux for Inclined
Sprays
Authors: Visaria Milan , Mudawar Issam
Published: December 2007

This study provides a new systematic approach to predicting the effects of spray inclination on critical heat flux (CHF). Experiments were performed with three pressure spray nozzles over a broad range of inclination angles at five flow rates and subcoolings of 15°C and 25°C. These experiments also included high-speed video analysis of spray formation, impact, and recoil for a 1.0×1.0cm2 test surface. Inclined sprays produced elliptical impact areas, distorted by lateral liquid flow that provided partial resistance to dryout along the downstream edge of the impact ellipse. These observations are used to determine the locations of CHF commencement along the test surface. A new theoretical model shows that increasing inclination angle away from normal decreases both the spray impact area and the volumetric flux. These trends explain the observed trend of decreasing CHF with increasing inclination angle. Combining the new model with a previous point-based CHF correlation shows great success in predicting the effects of spray inclination on CHF.
Simultaneous Electrothermal Test Method for Pyroelectric Microsensors
Authors: Smith Brian , Amon Cristina
Published: December 2007

Pyroelectric film materials, including polyvinylidene fluoride (PVDF) and its copolymers (e.g., P(VDF/trifluoroethylene)), are attractive candidates for low-cost infrared detection and imaging applications due to their compatibility with complementary metal-oxide semiconductor processing and inexpensive packaging requirements compared to semiconductor-based detectors. The pyroelectric coefficient (p) describes the material’s electric response to a change in sensor temperature and is the main contributor to the sensitivity and detectivity of the system. However, this value can vary greatly with film fabrication and poling processes, and its measurement is often highly coupled to the material’s thermal diffusivity. This paper describes a new approach to film characterization that combines the popular “3-omega” technique for thermal characterization with a modified version of the laser intensity modulation method for determining the film’s pyroelectric coefficient. The new method is capable of simultaneously measuring film conductivity, diffusivity, and pyroelectric coefficient. It could increase the accuracy of the pyroelectric measurements by providing in situ thermal data to the electrical model instead of relying on published values or thermal measurements of a different sample. We also present a fabrication process that can be used to pole and measure a variety of pyroelectric materials and a mathematical framework to study the thermal phenomena of the setup. The thermal model is used to highlight the methodology’s sensitivity to uncertainties in the geometric and material property values of the layers surrounding the pyroelectric film.
Isothermal Cyclic Bend Fatigue Test Method for Lead-Free Solder Joints
Authors: Pang John H. L. , Che F. X.
Published: December 2007

Isothermal three-point and four-point cyclic bend fatigue test methods have been developed for Sn–Ag–Cu solder joints. Reported bend tests from the literature were conducted at room temperature (25°C) and there is lack of data for lead-free solder joints. In this study, very-thin quad flat no-lead (VQFN) assembly with Sn–Ag–Cu lead-free solder was tested under three-point and four-point cyclic bending loads at both room temperature (25°C) and high temperature (125°C). The correlation between three-point and four-point bend tests was developed. Two different board surface finishes of electroless Ni and immersion gold (ENIG) and organic solderability preservatives (OSP) were investigated. Bending fatigue resistance of VQFN with OSP finish is slightly better than ENIG finish case. The acceleration factor of failure at high temperature (125°C) is higher than that at room temperature (25°C). Finite element analysis modeling and simulation were performed for different test conditions to investigate the solder joint stress-strain behavior. Volume-averaged energy density was used as a fatigue damage parameter and energy-based bending fatigue models were developed for VQFN with Sn–Ag–Cu solder joint under cyclic bending load at both 25°C and 125°C.
Web 2.0 technologies for undergraduate and postgraduate medical education: an online survey
Authors: Sandars J , Schroter S
Published: December 2007

Objectives

To identify the current familiarity and use of Web 2.0 technologies by medical students and qualified medical practitioners, and to identify the barriers to its use for medical education.

Methods

A semi-structured online questionnaire survey of 3000 medical students and 3000 qualified medical practitioners (consultants, general practitioners and doctors in training) on the British Medical Association's membership database.

Results

All groups had high familiarity, but low use, of podcasts. Ownership of digital media players was higher among medical students. There was high familiarity, but low use, of other Web 2.0 technologies except for high use of instant messaging and social networking by medical students. All groups stated that they were interested in using Web 2.0 technologies for education but there was lack of knowledge and skills in how to use these new technologies.

Conclusions

There is an overall high awareness of a range of new Web 2.0 technologies by both medical students and qualified medical practitioners and high interest in its use for medical education. However, the potential of Web 2.0 technologies for undergraduate and postgraduate medical education will only be achieved if there is increased training in how to use this new approach.
Renal localization and regulation of 15-hydroxyprostaglandin dehydrogenase
Authors: Yao Bing , Xu Jie , Harris Raymond C. , Zhang Ming-Zhi
Published: December 2007

Tissue prostaglandin levels are determined by both biosynthesis and catabolism. The current studies report the expression and localization of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), a key enzyme in prostaglandin catabolism in the kidneys. We also investigated potential interactions between 15-PGDH and cyclooxygenase (COX), a key enzyme in prostaglandin biosynthesis. Both 15-PGDH mRNA and protein levels were significantly higher in kidney cortex than in papilla, which is opposite to the expression pattern of COX-2. In situ hybridization indicated that 15-PGDH mRNA was mainly localized to the tubular epithelial cells in kidney cortex and outer medulla but not in the glomerulus or papilla. Dual immunofluorescent staining indicated that 15-PGDH was expressed in the proximal tubule, cortical, and outer medullary thick ascending limb and collecting duct but not in the macula densa or papilla. 15-PGDH levels were significantly lower in a macula densa cell line (MMDD1) than in a proximal tubule cell line. Although a high-salt diet decreased COX-2 expression in macula densa, it increased macula densa 15-PGDH expression in both mouse and rat kidneys. In MMDD1 cells, a COX-2 inhibitor increased 15-PGDH, whereas a COX-1 inhibitor had no effect. Furthermore, intense 15-PGDH immunofluorescent staining was found in both macula densa and glomerulus in COX-2 knockout mice. The intrarenal distribution of 15-PGDH and its interactions with COX-2 suggest that differential regulation of COX-2 and 15-PGDH may play an important role in determining levels of prostaglandins involved in regulation of salt, volume, and blood pressure homeostasis.
Recruiting Extrasynaptic NMDA Receptors Augments Synaptic Signaling
Authors: Harris Alexander Z. , Pettit Diana L.
Published: December 2007

N-Methyl-d-aspartate receptor (NMDAR) activation may promote cell survival or initiate cell death, with the outcome dependent on whether synaptic or extrasynaptic receptors are activated. Similarly, this differential activation has been proposed to govern the direction of plasticity. However, the physiological parameters necessary to activate extrasynaptic NMDARs in brain slices remain unknown. Using the irreversible use-dependent NMDAR antagonist MK-801 to isolate extrasynaptic NMDARs, we have tested the ability of short-stimulation trains from 5 to 400 Hz to activate these receptors on CA1 hippocampal slice pyramidal neurons. Frequencies as low as 25 Hz engage extrasynaptic NMDARs, with maximal activation at frequencies between 100 and 200 Hz. Since similar bursts of synaptic input occur during exploratory behavior in rats, our results demonstrate that “extrasynaptic” NMDARs regularly participate in synaptic transmission. Further, 175-Hz-stimulation trains activate all available synaptic and extrasynaptic dendritic NMDARs, suggesting these NMDARs act as synaptic receptors as needed, transiently increasing synaptic strength. Thus extrasynaptic NMDARs play a vital role in synaptic physiology, calling into question their status as “extrasynaptic.”
Preparation and Properties of Collagen/Modified Hyaluronic Acid Hydrogel for Biomedical Application
Authors: Kim Jae-Kyung , Lee Jung-Soo , Jung Hyo-Jung , Cho Jin-Hui , Heo Jee-In , Chang Yoon-Ho
Published: December 2007

Hydrogels composed of collagen and hyaluronic acid are types of crosslinked water-swellable polymers and possess vast potential for applications in the medical industry. Collagen (Co) is the major structural protein of connective tissues such as skin, tendon and cartilage. Hyaluronic
acid (HA) is a non-immunogenic, non-adhesive glycosaminoglycan that has a high water absorption property and plays significant roles in several cellular processes. The purpose of this study is to prepare a collagen (Co)-modified hyaluronic acid (MHA) hydrogel and investigate its potential
utility for biomedical products such as wound dressing materials. Collagen (Co, type I) was obtained from pig skin and mucopolysaccharide-HA was modified by a poly (ethylene glycol) diglycidyl ether (PEGDGE) crosslinker. Thermal stability, swelling behavior, and mechanical strength of Co-MHA
hydrogel according to different mass ratios of Co and MHA in hydrogel networks were investigated. The physical properties of the hydrogel were measured by SEM, Differential Scanning Calorimetry (DSC), Thermal Gravity Analysis (TGA), and a Universal Testing Machine (UTM). The cell viability
of Co-MHA hydrogel was also evaluated using an in vitro MTT assay.
Nanocrystalline Formation in Immiscible Cu-Mo System Subjected to Mechanical Alloying
Authors: Lee Chung-Hyo , Lee Seong-Hee
Published: December 2007

The mechanical alloying process has been studied on the Cu-Mo system, the atomic pair of which is characterized by a positive heat of mixing of +19 kJ/mol. The EXAFS and X-ray diffraction measurements have been employed to analyze the structural changes taking place during milling.
Two phases mixture of nanocrystalline fcc-Cu and bcc-Mo with a grain size of 10 nm has been formed by MA of Cu30Mo70 powders for 200 hours. The structural analysis based on the EXAFS spectra revealed that bcc and fcc crystal structure clearly do not change around Mo and
Cu atoms up to 200 h of milling, respectively. Studies of the thermodynamical considerations by DSC analyses confirmed that the alloying does not occur even after 200 hours of MA in Cu-Mo system.
Cellular Toxicity of Inorganic Hydroxide Nanoparticles
Authors: Choi Soo-Jin , Oh Jae-Min , Park Taeun , Choy Jin-Ho
Published: December 2007

Layered double hydroxides (LDHs), anionic clays, have attracted increasing interest as nanovehicles for delivering genes, drugs, and bio-active molecules into cells. However, no attempts have been made to evaluate the potential undesirable effects of LDH nanoparticles. The cytotoxicity
of LDHs with different chemical compositions (ZnAl- and MgAl-LDH) was systematically evaluated in various cell types, such as human normal cells, carcinoma cells, and red blood cells, by measuring cell viability, cell proliferation, membrane damage, and hemolytic effect. No significant cytotoxic
effects could be seen in both cases, but ZnAl-LDH was determined to be slightly more toxic than MgAl-LDH in terms of membrane damage and hemolysis induction. It is, therefore, expected that LDHs could be promising candidates for novel inorganic drug delivery carriers.
Autothermal Reforming of Propane Over Ni Catalysts Supported on a Variety of Perovskites
Authors: Lim SeungSoo , Moon DongJu , Kim JongHo , Kim YoungChul , Park NamCook , Shin JaeSoon
Published: December 2007

Autothermal reforming of propane for hydrogen over Ni catalysts supported on a variety of perovskites was performed in an atmospheric flow reactor. Perovskite is known for its higher thermal stability and oxygen storage capacity, but catalytic activity of itself is low. A sites of the
ABO3 structured perovskites were occupied by La while B sites by one of Fe, Co, Ni, and Al by citrate method. The composition of the reactant mixture was H2O/C/O2 = 8.96/1.0/1.1. The changes in the states of the catalysts after reaction were analyzed by XRD,
TPD, and TGA. Ni/LaAlO3 catalyst maintained the perovskite structure after reaction. It showed higher hydrogen yield and thermal stability compared to those of the catalysts with Fe, Co, or Ni in B sites. Catalysts prepared by deposition-precipitation (DP) method showed higher activity
than those prepared by impregnation method, presumably due to the smaller sizes of the NiO crystal particles.
Advances in infrared technology for the online monitoring of injection moulding: application to the understanding of the nature of contact at the polymer—mould interface
Authors: Bendada A. , Derdouri A. , Simard Y. , Lamontagne M.
Published: December 2007

We describe a novel online infrared method for remote sensing of the surface and the bulk temperatures of polymers during injection moulding. The method may also be applied to other polymer forming processes such as extrusion and blow moulding. The key feature of the new method is the use of a hollow optical fibre that is incorporated into the injection mould to transmit the thermal radiation from the target to the sensor. The main characteristic of the hollow optical fibre is that it exhibits low transmission loss of the thermal energy in the mid-and far-infrared, and no end reflection. This allows measurement of quite low temperatures, as low as near room temperature. Conventional optical fibre thermometers can neither measure such low temperature ranges nor measure the polymer surface temperature. In this article, we present the first online results of critical tests of the new device. A Husky injection moulding press was used for the experiments. Good correlation was found between the radiometric results and those obtained with a thermal probe inserted near the polymer—mould interface, and with infrared imaging after the polymer part was ejected from the injection mould. In the second part of the paper, we show how the new infrared device can be used to give a better insight on the time evolution of the thermal contact between polymer and mould through the different phases of a typical injection moulding cycle. The experimental results show that thermal contact between polymer and mould is not negligible and not constant with time.
Recovery of high purity zinc from filter ash produced during the thermal treatment of waste and inerting of residual materials
Authors: Schlumberger Stefan , Schuster Michael , Ringmann Stefan , Koralewska Ralf
Published: December 2007

The method described below recovers zinc, a valuable metal that is present in high concentrations in filter ash from the thermal treatment of waste, and returns the filter ash stripped of heavy metals to the combustion process in order to destroy organic substances. On an industrial scale, the heavy metals in the filter ash were mobilized by means of hydrochloric acid in the acidic fluids produced in the flue-gas scrubbing process without the addition of further chemicals. A pilot plant for implementing the selective reactive extraction (SRE) method on the ash extracts, using a highly selective complexant, was operated over a period of several months in order to obtain a concentrated, high-purity zinc salt solution (mono metal solution). A zinc depletion rate of 99.8% in the aqueous extract was achieved using mixer—settler units. The residual zinc concentration in the waste water was then < 2 mg L—1. By stripping the loaded organic phase, a concentrated, high-purity mono metal solution with 190 g L— 1 zinc was obtained. Zinc metal with a purity > 99.99% is then separated by means of electrolysis. To destroy organic substances present in the filter ash, particularly dioxins and furans, the extracted filter ash cake was returned to the combustion process together with household waste. Plant operation, raw and pure gas parameters, and quality of the bottom ash produced were not impacted by such recirculation. The profitability of the overall process is attributable both to the recovery of valuable zinc metal and to the cost savings made in waste water treatment and in the disposal of the waste combustion residues because the remaining mixture of filter ash and bottom ash can be reused in a combined form. This method therefore supports the sustainable and economically viable reuse of filter ash.
Strategies for improving recycling behaviour within the Cornwall National Health Service (NHS) in the UK
Authors: Tudor Terry L. , Barr Stewart W. , Gilg Andrew W.
Published: December 2007

This paper examines strategies for improving recycling behaviour within the Cornwall National Health Service (NHS). Using quantitative (questionnaires and waste bin analyses) and qualitative (ethnography and interviews) methodologies, the study examined the waste management practices of staff from the Cornwall NHS. It was found that employee participation in waste recycling at work was low due to a range of factors including NHS focus and policies, group norms, and individual attitudes and beliefs about sustainable waste management. Recommendations for improving the sustainability of NHS, employee waste management practices, with a specific focus on recycling are included in the paper. These recommendations include measures focused towards both the NHS organization and individual staff members.
Interactions between Dopamine and Melatonin Organize Circadian Rhythmicity in the Retina of the Green Iguana
Authors: Bartell Paul A. , Miranda-Anaya Manuel , McIvor Wilson , Menaker Michael
Published: December 2007

Circadian physiology in the vertebrate retina is regulated by several neurotransmitters. In the lateral eyes of the green iguana the circadian rhythm of melatonin content peaks during the night while the rhythm of dopamine peaks during the day. In the present work, the authors explore the interaction of these 2 neurotransmitters during the circadian cycle. They depleted retinal dopamine with intravitreal injections of 6-hydroxydopamine (6-OHDA) and measured ocular melatonin content in vivo throughout 1 circadian cycle. The circadian rhythm of ocular melatonin not only persisted but increased 10-fold in amplitude. This increase was substantially reduced by the intraocular administration of dopamine. 6-OHDA-treated retinas, unlike those from untreated animals, did not express a circadian rhythm of melatonin synthesis in vitro. To deplete retinal melatonin, the authors pinealectomized iguanas and blocked retinal melatonin synthesis by depleting serotonin with intraocular injections of 5,6-dihydroxytryptamine. In animals so treated, they found that the circadian rhythm of retinal dopamine content was abolished, the levels of dopamine were lowered, and the levels of dopamine metabolites were greatly increased. The data suggest that in iguanas, the amplitude of the circadian rhythm of melatonin synthesis in the eye is suppressed by dopamine while the rhythm of dopamine depends, at least in part, on the presence of melatonin.
Front Loading Visits: A Best Practice Measure to Decrease Rehospitalization in Heart Failure Patients
Authors: Rogers Joanne M. , Schott Donna K.
Published: December 2007

Home care agencies are under pressure to deliver high-quality care with outcomes that demonstrate reduced patient rehospitalization. One approach found to be successful in reducing rehospitalization of heart failure patients is front loading visits. Our recent study showed front loading was effective for patients with heart failure, dramatically decreasing rehospitalization by more than one half (30.4% to 16%). Other methods utilized to enhance front loading are supplementation of visits with telehealth and/or telemonitoring and the use of established care paths. This article discusses the many challenges home care agencies face in implementing redesign and these best practice measures.
Jean Baudrillard and the Definitive Ambivalence of Gaming
Authors: Coulter Gerry
Published: December 2007

Baudrillard's “game” was writing and in it, he had interesting things to say about games. This article explores his thought concerning our passion for games and the experimental role gamers perform in our culture. It concludes that Baudrillard was ambivalent about gaming despite the fact that he saw it as a central aspect of the obsession of our age—the lack of distinction between the real and the virtual.
Review: Therapy for the altered mineral metabolism of chronic kidney disease: implications for vascular calcification
Authors: Saab Georges , Whaley-Connell Adam T. , Khanna Ramesh , Sowers James R.
Published: December 2007

The development of chronic kidney disease (CKD) is associated with poor outcomes largely due an increased likelihood of adverse cardiovascular events. Many factors are playing a role in cardiovascular disease in CKD including the development of vascular calcification (VC). Studies have indeed shown that the presence of VC is associated with decreased survival among patients with CKD. The pathogenesis of VC is itself multi-factorial. LikeLy playing a significant role is the altered mineral metabolism of CKD. Management of the altered mineral metabolism in CKD is quite difficult and may also play a role in the pathogenesis of VC. In this manuscript, we will review the pathogenesis of the altered mineral metabolism of CKD, its management, and how both may play a role in the development of VC.
Review: The role of noninvasive hemodynamic monitoring in the evaluation and treatment of hypertension
Authors: Ferrario Carlos M. , Basile Jan , Bestermann William , Frohlich Edward , Houston Mark , Lackland Daniel T. , Smith Ronald D. , Wise Daniel L.
Published: December 2007

Advances in the understanding of the mechanisms accounting for the elevation of arterial pressure in essential hypertension suggest that there is value in assessing the relative contribution of hemodynamic factors in tailoring specific therapies to control arterial pressure. The non-invasive method of impedance cardiography (ICG) to measure hemodynamic abnormalities in hypertensive patients has emerged as a valuable adjuvant in the decision-making process of selecting antihypertensive agents. The technique is both accurate and reproducible in delineating the hemodynamic mechanisms of hypertension, comparing age-and gender-related changes in hemodynamics, detecting the presence of left ventricular dysfunction, and demonstrating clinically significant improvement in blood pressure control using ICG-guided therapy.
Review: Vascular remodeling: implications for small artery function and target organ damage
Authors: Sonoyama Kazuhiko , Greenstein Adam , Price Anna , Khavandi Kaivan , Heagerty Tony
Published: December 2007

At the level of the small artery, essential hypertension is associated with eutrophic inward remodeling. This involves reduction in lumen diameter by an increase in wall thickness. Previously thought to involve either hypertrophy or hyperplasia of the vascular smooth muscle cells in the media, it is now felt to be mediated by a functional property of the wall: myogenic tone. This is the ability of an artery to contract in response to an increase in intraluminal pressure. This autoregulatory function is also vital to ensure stabilisation of distal capillary pressures and so prevent, or limit, organ damage. Indeed in any animal model studied, when myogenic autoregulation is affected, target organ damage ensues. We have also observed, in two studies, that when myogenic autoregulation is damaged in the context of hypertension, eutrophic remodeling is replaced by an outward growth of the arterial wall with preservation of lumen diameter. This is called hypertrophic remodeling and, independently, has been observed by a number of groups in small arteries from patients with type 2 diabetes. We believe that this is a key reason for the unique propensity to hypertensive injury seen in patients with diabetes. We also discuss the significance of integrins, transmembrane proteins with wide ranging functions; from initiation of cell migration to intracellular signalling. Two particular integrins, α5 β1 and ανβ3, have been found to be necessary for both normal myogenic autoregulation and eutrophic remodeling and the possibility that damage to these may occur in diabetes is examined.
Immune reconstitution after unrelated cord blood transplants in adults
Authors: Gluckman Eliane
Published: December 2007

The article by Komanduri et al in this issue of Blood describes immune reconstitution after human leukocyte antigen (HLA)-mismatched cord-blood transplantation. As expected, a profound reconstitution deficiency was observed; a study of some subpopulations could be predictive of the outcome.
A2B adenosine receptor dampens hypoxia-induced vascular leak
Authors: Eckle Tobias , Faigle Marion , Grenz Almut , Laucher Stefanie , Thompson Linda F. , Eltzschig Holger K.
Published: December 2007

Extracellular adenosine has been implicated in adaptation to hypoxia and previous studies demonstrated a central role in vascular responses. Here, we examined the contribution of individual adenosine receptors (ARs: A1AR/A2AAR/A2BAR/A3AR) to vascular leak induced by hypoxia. Initial profiling studies revealed that siRNA-mediated repression of the A2BAR selectively increased endothelial leak in response to hypoxia in vitro. In parallel, vascular permeability was significantly increased in vascular organs of A2BAR−/−-mice subjected to ambient hypoxia (8% oxygen, 4 hours; eg, lung: 2.1 ± 0.12-fold increase). By contrast, hypoxia-induced vascular leak was not accentuated in A1AR−/−-, A2AAR−/−-, or A3AR−/−-deficient mice, suggesting a degree of specificity for the A2BAR. Further studies in wild type mice revealed that the selective A2BAR antagonist PSB1115 resulted in profound increases in hypoxia-associated vascular leakage while A2BAR agonist (BAY60-6583 [2-[6-amino-3,5-dicyano-4-[4-(cyclopropylmethoxy)-. phenyl]pyridin-2-ylsulfanyl]acetamide]) treatment was associated with almost complete reversal of hypoxia-induced vascular leakage (eg, lung: 2.0 ± 0.21-fold reduction). Studies in bone marrow chimeric A2BAR mice suggested a predominant role of vascular A2BARs in this response, while hypoxia-associated increases in tissue neutrophils were, at least in part, mediated by A2BAR expressing hematopoietic cells. Taken together, these studies provide pharmacologic and genetic evidence for vascular A2BAR signaling as central control point of hypoxia-associated vascular leak.
Perception versus polysomnographic assessment of sleep in CFS and non-fatigued control subjects: results from a population-based study
Authors: Majer Matthias , Jones James F , Unger Elizabeth R , Youngblood Laura Solomon , Decker Michael J , Gurbaxani Brian , Heim Christine , Reeves William C
Published: December 2007

Background

Complaints of unrefreshing sleep are a prominent component of chronic fatigue syndrome (CFS); yet, polysomnographic studies have not consistently documented sleep abnormalities in CFS patients. We conducted this study to determine whether alterations in objective sleep characteristics are associated with subjective measures of poor sleep quality in persons with CFS.

Methods

We examined the relationship between perceived sleep quality and polysomnographic measures of nighttime and daytime sleep in 35 people with CFS and 40 non-fatigued control subjects, identified from the general population of Wichita, Kansas and defined by empiric criteria. Perceived sleep quality and daytime sleepiness were assessed using clinical sleep questionnaires. Objective sleep characteristics were assessed by nocturnal polysomnography and daytime multiple sleep latency testing.

Results

Participants with CFS reported unrefreshing sleep and problems sleeping during the preceding month significantly more often than did non-fatigued controls. Participants with CFS also rated their quality of sleep during the overnight sleep study as significantly worse than did control subjects. Control subjects reported significantly longer sleep onset latency than latency to fall asleep as measured by PSG and MSLT. There were no significant differences in sleep pathology or architecture between subjects with CFS and control subjects.

Conclusion

People with CFS reported sleep problems significantly more often than control subjects. Yet, when measured these parameters and sleep architecture did not differ between the two subject groups. A unique finding requiring further study is that control, but not CFS subjects, significantly over reported sleep latency suggesting CFS subjects may have an increased appreciation of sleep behaviour that may contribute to their perception of sleep problems.