bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors in social comparison of performance influencing actual performance
Authors: Rijsman J. B.
Published: May 2007

Seven experiments were conducted which measured changes in the subjects' actual performance resulting from manipulated personal and categorical comparison of performance with another subject. In line with Festinger's (1954) theory of social comparison of ability, it was found that subjects who were visually isolated from sources of evaluation (setting 2, experiment 2 and 3) showed relatively low performance after a VI (very inferior) or VS (very superior) outcome and relatively high performance after an EQ (equal) outcome, whereas subjects who were visually exposed to sources of evaluation (setting 1, experiment 1 and 4) showed relatively low performance only after a VS outcome and relatively high performance after both a VI and EQ outcome. When (also in setting 1) the manipulation of outcome was combined with a manipulation of expectation (experiment 5), it was found that an EQ expectation did not alter the original pattern of outcome effects, but that a VI or VS expectation markedly influenced the effect of outcome: A complete confirmation of VI expectation and an almost complete disconfirmation of VS expectation resulted in relatively high performance, whereas all other combinations of VI or VS expectation with a given outcome resulted in relatively low performance. Finally, it was found that changing the manipulation of personal comparison of performance of the previous experiments into a manipulation of categorical comparison of performance of the previous experiments into a manipulation of categorical comparison of performance (experiment 6a and 6b) resulted in a pattern of data wich was about the opposite of the typical previous pattern. In setting 1 (experiment 6a), the subjects' performance was relatively low after being categorized into a VI or EQ category and relatively high after being categorized into a VS category, whereas in setting 2 (experiment 6b) both the VI and VS categorization resulted in the same performance and the EQ categorzation resulted in a slightly lower performance.
Whose ideology? A rejoinder to M. Plon
Authors: Nemeth Charlan
Published: May 2007

M. Plon commits the same offense that he finds so odious in American social psychology: A confounding of political axioms and scientific reasoning. His desire to demonstrate ideological blindness in Americans leads him to misinterpret some published works on the Prisoner's Dilemma paradigm in bargaining research and to ignore the issue of the most useful balance in emphasis between conflict maintenance and conflict resolution when these topics are studied experimentally. Thus, M. Plon's angry attack is not a clarification of the deep issues that he essays but, rather, another data point that will itself need to be understood.
On a question of orthodoxy
Authors: Plon Michel
Published: May 2007

Judging from the main point of the replies received, a Marxist position which does not accept a dialogue with social psychology is not allowed. To indicate that such a position is Marxist only in name, and thus usurped, we are rapidly accused of economism, qualified as ‘orthodox’ and finally, last but not least, given the label ‘Stalinist’.

The psycho‐sociologists are firmly locked up in the rhetoric of the dilemma. The two positions — theoretical and political — which are presented in the reply by Morton Deutsch are in reality complementary: Their common characteristic is that they forget the main point of Marxism‐Leninism, the thesis of the primacy of the class struggle. To accept social psychology without asking oneself questions about its meaning, or to ignore social psychology by considering it as an out‐of‐date ideology, leads to the same result, namely, leaving open the place of a Marxist‐Leninist theory of ideology.
Detection of recombinant human erythropoietin in urine for doping analysis: Interpretation of isoelectric profiles by discriminant analysis
Authors: Lasne Françoise , Thioulouse Jean , Martin Laurent , de Ceaurriz Jacques
Published: May 2007

The detection in urine of recombinant human erythropoietin (rHuEPO), a hormone misused by endurance athletes as a doping agent, is based on the differentiation of its isoelectric pattern from that of the corresponding natural hormone. Different empirical criteria have been proposed for discriminating the images of the patterns but none of them have been elaborated from a rational statistical approach. Discriminant analysis was applied to a dataset of profiles defined as positive (116 profiles from 26 subjects) (presence of rHuEPO and possibly residual natural endogenous hormone) and negative (131 profiles from 131 subjects) (presence of natural endogenous hormone only). The different bands were numbered according to a template of 16 possible positions and their relative intensities constituted the 16 variables of the statistical analysis. This method was then tested with data from an administration trial of low doses (6.7–10 IU/kg) following high‐dose (265 IU/kg) injections (71 profiles from one subject). The analysis of the dataset clearly separated the negative and positive profiles. A cross‐validation procedure confirmed that the analysis was extremely stable: with ten‐fold cross‐validation, no false positives were observed even with 100 000 simulations. Furthermore, the detection of rHuEPO in the profiles from the low‐dose trial was greatly improved in comparison with a previously validated empirical criterion.
Genetic microheterogeneity of human transthyretin detected by IEF
Authors: Altland Klaus , Benson Merrill D. , Costello Catherine E. , Ferlini Alessandra , Hazenberg Bouke P. C. , Hund Ernst , Kristen Arnt V. , Linke Reinhold P. , Merlini Giampaolo , Salvi Fabrizio , Saraiva Maria J. , Singer Reinhard , Skinner Martha , Winter Pia
Published: May 2007

Mutations of the human transthyretin (TTR) gene have attracted medical interest as a cause of amyloidosis. Recently, we have described in detail an electrophoretic procedure with PAGE followed by IEF in urea gradients for the study of the microheterogeneity of TTR monomers (Altland, K., Winter, P., Sauerborn, M. K., Electrophoresis 1999, 20, 1349–1364). In this paper, we present a study on 49 different mutations of TTR including 33 that result in electrically neutral amino acid substitutions. The aims of the investigation were to test the sensitivity of the procedure to detect TTR variants in patients with TTR amyloidosis and their relatives and to identify some common characteristics that could explain the amyloidogenicity of these variants. We found that all tested amyloidogenic mutations could be detected by our method with the exception of those for which the corresponding variant was absent in plasma samples. Most of the electrically neutral amyloidogenic TTR variants had in common a reduced conformational stability of monomers by the activity of protons and urea. For three variants, e.g. TTR–F64L, TTR–I107V and TTR–V122I, the monomers had a conformational stability close to that of normal monomers but we found experimental and structural arguments for a weakening of the monomer‐monomer contact. All types of amyloidogenic mutations affected the stability of TTR tetramers.
NG2‐positive cells generate A2B5‐positive oligodendrocyte precursor cells
Authors: Baracskay Karen L. , Kidd Grahame J. , Miller Robert H. , Trapp Bruce D.
Published: May 2007

Cellular specification of the oligodendrocyte lineage occurs through a series of stages identified by expression of distinct biochemical characteristics. The best characterized oligodendrocyte progenitor cell (OPC) in vitro is the bipotential O2‐A progenitor, identified by labeling with monoclonal antibody A2B5, which proliferates predominantly in response to platelet derived growth factor (PDGF). The cellular ancestors of O2‐A progenitor cells are currently unclear. In vivo OPCs can be identified by expression of the cell surface markers NG2 (a sulfated proteoglycan) and platelet derived growth factor receptor αR). Substantial evidence supports the generation of oligodendrocytes from NG2+, PDGFαR+ cells both in vivo and in vitro. The developmental relationship between NG2+ cells and A2B5− positive cells is unknown and it is unclear whether they represent identical, partially overlapping or nonoverlapping populations of cells. Here we show that in cultures of developing brain NG2+ and A2B5+ cells arise from overlapping cell populations. NG2+ cells appear prior to the expression of A2B5+ cells and generate A2B5+ cells. We propose that during development NG2+/A2B5− cells (pre‐OPCs) represent the direct ancestor to A2B5+ O2A progenitor cells (OPCs). © 2007 Wiley‐Liss, Inc.
An opportunity cost approach to sample size calculation in cost‐effectiveness analysis
Authors: Gafni A. , Walter S. D. , Birch S. , Sendi P.
Published: May 2007

The inclusion of economic evaluations as part of clinical trials has led to concerns about the adequacy of trial sample size to support such analysis. The analytical tool of cost‐effectiveness analysis is the incremental cost‐effectiveness ratio (ICER), which is compared with a threshold value (λ) as a method to determine the efficiency of a health‐care intervention. Accordingly, many of the methods suggested to calculating the sample size requirements for the economic component of clinical trials are based on the properties of the ICER. However, use of the ICER and a threshold value as a basis for determining efficiency has been shown to be inconsistent with the economic concept of opportunity cost. As a result, the validity of the ICER‐based approaches to sample size calculations can be challenged. Alternative methods for determining improvements in efficiency have been presented in the literature that does not depend upon ICER values. In this paper, we develop an opportunity cost approach to calculating sample size for economic evaluations alongside clinical trials, and illustrate the approach using a numerical example. We compare the sample size requirement of the opportunity cost method with the ICER threshold method. In general, either method may yield the larger required sample size. However, the opportunity cost approach, although simple to use, has additional data requirements. We believe that the additional data requirements represent a small price to pay for being able to perform an analysis consistent with both concept of opportunity cost and the problem faced by decision makers. Copyright © 2007 John Wiley & Sons, Ltd.
Delayed behavioral and endocrine effects of sarin and stress exposure in mice
Authors: Mach Mojmir , Grubbs Robert D. , Price William A. , Nagaoka Maya , Dubovický Michal , Lucot James B.
Published: May 2007

The organophosphorus agent sarin is a potent inhibitor of acetylcholinesterase. Experiments tested the influence of exposure to low doses of sarin along with psychological stress on delayed behavioral and endocrine changes in mice. Motor activity, acoustic startle response (ASR), pre‐pulse inhibition (PPI) of ASR, activity of cholinesterase in blood and catecholamine levels in adrenals were evaluated after low dose sarin exposure (3 × 0.4 LD50subcutaneously) combined with chronic intermittent stress in C57BL/6J mice. While sarin alone produced depression of motor activity, no interaction of the stress with sarin exposure was observed. Cholinesterase activity was significantly reduced 24 h after exposure to sarin; however, the basal activity was re‐established 3 weeks later. The combination of low dose sarin exposure and stress produced delayed behavioral change manifested as excessive grooming together with endocrine alterations in adrenals 7 weeks after exposure. The size of the adrenals in the combined exposure group was increased and the concentration of catecholamines was significantly decreased. In conclusion, these findings indicate that sarin in low doses is more dangerous when combined with shaker stress inducing delayed behavioral and endocrine changes. Copyright © 2007 John Wiley & Sons, Ltd.
Bone response to three different chemical compositions of fluorcanasite glass‐ceramic
Authors: da Rocha Barros Valdemar Mallet , Liporaci Jorge Luiz J. , Rosa Adalberto L. , Junqueira Marcela Caffarena , de Oliveira Paulo Tambasco , Johnson Anthony , van Noort Richard
Published: May 2007

The aim of this study was to evaluate the bone response to three fluorcanasite glass‐ceramic compositions with different solubilities (K3, K5, and K8) after implantation in a femur rabbit model. Fluorcanasite glass‐ceramic rods were implanted bilaterally in the mid‐shafts rabbit femurs. Implants were harvested at 8 and 12 weeks and prepared for histological and histomorphometric analyses at the light microscope level. Bioglass 45S5 rods were used as a control material. At 8 weeks, all fluorcanasite glass‐ceramics were entirely surrounded by a nonmineralized connective tissue. At 12 weeks, reduced areas of bone tissue were observed in the cortical area in direct contact with the K3 and K5 fluorcanasite glass‐ceramics compared to Bioglass 45S5, whereas no bone tissue was observed in direct contact with the K8 surface. Bone‐to‐implant contact in the cortical area was affected by the material chemical composition and ranked as follows: Bioglass 45S5 > K3 > K5 > K8 (p = 0.001). In the bone marrow, a layer of fibrous connective tissue formed in direct contact with the fluorcanasite glass‐ceramics and Bioglass 45S5, and only rarely exhibited contact osteogenesis. All the fluorcanasite glass‐ceramics appeared to degrade in the biological environment. The solubility ratio did not alter significantly the biological reply of the fluorcanasite glass‐ceramics in vivo. Further modifications of the chemical composition of the fluorcanasite glass‐ceramic are required to increase the stability of the material in vivo. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Characterization, degradation, and mechanical strength of poly(D,L‐lactide‐co‐ϵ‐caprolactone)‐poly(ethylene glycol)‐poly(D,L‐lactide‐co‐ϵ‐caprolactone)
Authors: Bramfeldt Hanna , Sarazin Pierre , Vermette Patrick
Published: May 2007

A series of three biocompatible P(CL‐co‐LA)‐PEG‐P(CL‐co‐LA) copolymers were synthesized using ring‐opening polymerization and characterized by 1H‐NMR, gel permeation chromatography, DSC, dynamic‐mechanical analysis, and X‐ray diffraction. The number of monomer units was kept constant, while the D,L‐LA fraction was varied so as to constitute 0, 30, or 70% of the end segments. The molecular weights were sufficiently high to eventually permit 3D scaffold preparation. A degradation study was carried out over 26 weeks, and the effect of monomer composition on the rate of degradation as well as on changes in mechanical strength was investigated. Pure polycaprolactone (PCL)‐poly(ethylene glycol) (PEG)‐PCL copolymer, P(100/0), was a crystalline material displaying no measurable mass loss, a 30% reduction in mean molecular weight (Mn), and only very slight changes in tensile strength. The random incorporation of 30 and 70% D,L‐LA into the end sections of the polymer chain, produced more and more amorphous materials, exhibiting increasingly high rates of degradation, mass loss, and loss of tensile strength. Compared with random P(CL‐co‐LA), the presence of the PEG block was found both to improve hydrophilicity and thus the rate of degradation and to infer a stabilizing quality, thereby pacing the decrease in tensile strength during degradation. The tested copolymers range from materials exhibiting low mechanical strength and high rate of degradation to slow‐degrading materials with high mechanical strength suitable, e.g., for three‐dimensional scaffolding. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Effects of BMP‐2 and pulsed electromagnetic field (PEMF) on rat primary osteoblastic cell proliferation and gene expression
Authors: Selvamurugan Nagarajan , Kwok Sukyee , Vasilov Anatoliy , Jefcoat Stephen C. , Partridge Nicola C.
Published: May 2007

Bone morphogenetic proteins (BMPs) strongly promote osteoblast differentiation. Pulsed electromagnetic fields (PEMFs) promote fracture healing in non‐union fractures. In this study, we hypothesized that a combined BMP‐2 and PEMF stimulation would augment bone formation to a greater degree than treatment with either single stimulus. BMP‐2 maximally increased the proliferative activity of rat primary osteoblastic cells at 25 ng/ml concentration. Real‐time reverse transcription‐polymerase chain reaction (RT‐PCR) showed that BMP‐2 stimulated mRNA levels of alkaline phosphatase (ALP), α1 (I) procollagen, and osteocalcin (OC) in the differentiation phase and only OC mRNA expression in the mineralization phase after 24‐h treatment. Both BMP‐2 and PEMF (Spinal‐Stim) increased cell proliferation, which was additive when both agents were combined. PEMF alone or together with BMP‐2 increased only ALP mRNA expression and only during the differentiation phase 24 h after one 4‐h treatment. This effect was additive when both agents were combined. Continuous daily 4‐h treatment with PEMF alone or together with BMP‐2 increased expression of all three osteoblast marker genes during the differentiation phase and increased the mineralized matrix. This effect was additive when both agents were combined, suggesting that the two interventions may be working on different cellular pathways. Thus, a combined effect of BMP‐2 and PEMF in vitro could be considered as groundwork for in vivo bone development that may support skeletal therapy. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1213–1220, 2007
A robust method for automated background subtraction of tissue fluorescence
Authors: Cao Alex , Pandya Abhilash K. , Serhatkulu Gulay K. , Weber Rachel E. , Dai Houbei , Thakur Jagdish S. , Naik Vaman M. , Naik Ratna , Auner Gregory W. , Rabah Raja , Freeman D. Carl
Published: May 2007

This paper introduces a new robust method for the removal of background tissue fluorescence from Raman spectra. Raman spectra consist of noise, fluorescence and Raman scattering. In order to extract the Raman scattering, both noise and background fluorescence must be removed, ideally without human intervention and preserving the original data. We describe the rationale behind our robust background subtraction method, determine the parameters of the method and validate it using a Raman phantom against other methods currently used. We also statistically compare the methods using the residual mean square (RMS) with a fluorescence‐to‐signal (F/S) ratio ranging from 0.1 to 1000. The method, ‘adaptive minmax’, chooses the subtraction method based on the F/S ratio. It uses multiple fits of different orders to maximize each polynomial fit. The results show that the adaptive minmax method was significantly better than any single polynomial fit across all F/S ratios. This method can be implemented as part of a modular automated real‐time diagnostic in vivo Raman system. Copyright © 2007 John Wiley & Sons, Ltd.
The effect of instant green tea on the foaming and rheological properties of egg albumen proteins
Authors: Wu Weiguo , Clifford Mike , Howell Nazlin K
Published: May 2007

The effects of three varieties of instant green tea (from China, Japan and Kenya) on the foaming and thermal properties of 1% (w/v) egg albumen and the gelation properties of 5 and 15% (w/v) egg albumen were investigated. All varieties produced similar effects on the foaming and gelation properties of egg albumen, but to different extents depending on the tea constituents. Mixtures of 1% (w/v) egg albumen and 0.25–0.4% (w/v) instant green teas in distilled water showed the greatest foam expansion (800–1140%) and foam stability (97–100%) at 10 min after whipping compared with 1% (w/v) egg albumen alone (226% for foam expansion and 34% for foam stability). Addition of instant green teas at levels above 0.5% (w/v) decreased foam expansion and stability. Small‐deformation rheology of mixtures of 5% (w/v) egg albumen and 1 or 2% (w/v) instant green teas showed an initial increase in elastic modulus (G′) and viscous modulus (G″) followed by a small, broad peak, indicating that the binding of tea constituents (polyphenols) with proteins may be reversible between 20 and 54 °C; this peak was not seen for 5% (w/v) egg albumen on its own. Large‐deformation rheological tests also indicated increased strength of mixed egg albumen/green tea gels with increasing levels of instant green teas. Differential scanning calorimetry thermograms showed that for the same instant green tea a higher concentration decreased the onset and peak (Tm) temperatures and enthalpy change values of all egg albumen protein peaks. Copyright © 2007 Society of Chemical Industry
Rheological characterisation of polysaccharides extracted from brown seaweeds
Authors: Rioux Laurie‐Eve , Turgeon Sylvie L , Beaulieu Martin
Published: May 2007

Hydrocolloids from seaweeds have interesting functional properties, such as thickening or gelling ability. Structural characteristics of polysaccharides extracted from Québec seaweeds have not yet been established. Thus, the determination of the relationship between their structure and rheological behaviour is limited. Alginate and fucoidan were extracted using selective solvents from three species: Saccharina longicruris, Ascophyllum nodosum and Fucus vesiculosus. Structural analysis (total sugars, uronic acids, sulfates and molecular weight) and rheological characterisation were performed at different polysaccharide concentrations with and without the addition of NaCl. The results showed important variation between species. Fucoidan and alginate exhibited Newtonian behaviour. Fucoidan extracted from F. vesiculosus had the highest viscosity level, which might be explained by the degree of branching of the molecules. For alginate, the one extracted from S. longicruris showed a higher apparent viscosity. This result can partially be explained by the block proportion of alginate. The gelation profile of alginate was also determined for each species. The final storage modulus, G′, was variable for each species. Differences between species were observed for both polysaccharides as a result of structural variation. Copyright © 2007 Society of Chemical Industry
Evaluation of some essential oils as botanical fungitoxicants for the protection of stored food commodities from fungal infestation
Authors: Kumar Rajesh , Dubey Nawal K , Tiwari Om P , Tripathi Yamini B , Sinha Kauskal K
Published: May 2007

Essential oils from different parts of 18 plants belonging to 11 families were extracted and tested against two toxigenic strains of Aspergillus flavus Link through the poisoned food technique. The oil of Mentha arvensis was found to be effective against both strains of A. flavus and completely stopped the radial mycelial growth of A. flavus at 0.10 mg mL−1. It was found to be superior over the synthetic fungicides tested and showed a broad fungitoxic spectrum against A. niger, A. fumigatus, Botryodiplodia theobromae, Cladosporium cladosporioides, Fusarium oxysporum, Helminthosporium oryzae, Macrophomina phaseolina and Sclerotium rolfsii at 0.10 mg mL−1. The oil completely inhibited the aflatoxin B1 production by the toxigenic strain of A. flavus at 0.05 mg mL−1. Moreover, the Mentha oil also exhibited potent antioxidant activity in 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulphuric acid (ABTS) bioassay. Keeping in mind the side effects of synthetic pesticides and the global interest in botanical pesticides for plant protection due to their biodegradable nature, M. arvensis oil may be used as a botanical fungitoxicant against fungal attack to stored food commodities. The antiaflatoxigenic and antioxidant nature of the oil suggest the possibility of its exploitation for enhancing the shelf life of stored food commodities. Copyright © 2007 Society of Chemical Industry
A global database of domestic and international tourist numbers at national and subnational level
Authors: Bigano Andrea , Hamilton Jacqueline M. , Lau Maren , Tol Richard S.J. , Zhou Yuan
Published: May 2007

We present a new, global database on tourist destinations. The database differs from other databases in that it includes both domestic and international tourists; and it contains, for the most important destinations, data at national level as well as at lower administrative levels. Missing observations are interpolated using statistical models. The data are freely accessible on the internet. Copyright © 2007 John Wiley & Sons, Ltd.
Mathematical model that predicts the force–intensity and force–frequency relationships after spinal cord injuries
Authors: Ding Jun , Chou Li‐Wei , Kesar Trisha M. , Lee Samuel C.K. , Johnston Therese E. , Wexler Anthony S. , Binder‐Macleod Stuart A.
Published: May 2007

We have previously developed and tested a muscle model that predicts the effect of stimulation frequency on muscle force responses. The aim of this study was to enhance our isometric mathematical model to predict muscle forces in response to stimulation trains with a wide range of frequencies and intensities for the quadriceps femoris muscles of individuals with spinal cord injuries. Isometric forces were obtained experimentally from 10 individuals with spinal cord injuries (time after injury, 1.5–8 years) and then compared to forces predicted by the model. Our model predicted accurately the force–time integrals (FTI) and peak forces (PF) for stimulation trains of a wide range of frequencies (12.5–80 HZ) and intensities (150–600‐μs pulse duration), and two different stimulation patterns (constant‐frequency trains and doublet‐frequency trains). The accurate predictions of our model indicate that our model, which now incorporates the effects of stimulation frequency, intensity, and pattern on muscle forces, can be used to design optimal customized stimulation strategies for spinal cord–injured patients. Muscle Nerve, 2007
Pathogenic mitochondrial DNA mutations in protein‐coding genes
Authors: Wong Lee‐Jun C.
Published: May 2007

More than 200 disease‐related mitochondrial DNA (mtDNA) point mutations have been reported in the Mitomap (http://www.mitomap.org) database. These mutations can be divided into two groups: mutations affecting mitochondrial protein synthesis, including mutations in tRNA and rRNA genes; and mutations in protein‐encoding genes (mRNAs). This review focuses on mutations in mitochondrial genes that encode proteins. These mutations are involved in a broad spectrum of human diseases, including a variety of multisystem disorders as well as more tissue‐specific diseases such as isolated myopathy and Leber hereditary optic neuropathy (LHON). Because the mitochondrial genome contains a large number of apparently neutral polymorphisms that have little pathogenic significance, along with secondary homoplasmic mutations that do not have primary disease‐causing effect, the pathogenic role of all newly discovered mutations must be rigorously established. A scoring system has been applied to evaluate the pathogenicity of the mutations in mtDNA protein‐encoding genes and to review the predominant clinical features and the molecular characteristics of mutations in each mtDNA‐encoded respiratory chain complex. Muscle Nerve, 2007
Iron load and redox stress in skeletal muscle of aged rats
Authors: Altun Mikael , Edström Erik , Spooner Eric , Flores‐Moralez Amilcar , Bergman Esbjörn , Tollet‐Egnell Petra , Norstedt Gunnar , Kessler Benedikt M. , Ulfhake Brun
Published: May 2007

Loss of skeletal muscle mass (sarcopenia) is a major contributor to disability in old age. We used two‐dimensional gel electrophoresis and mass spectrometry to screen for changes in proteins, and cDNA profiling to assess transcriptional regulations in the gastrocnemius muscle of adult (4 months) and aged (30 months) male Sprague‐Dawley rats. Thirty‐five proteins were differentially expressed in aged muscle. Proteins and mRNA transcripts involved in redox homeostasis and iron load were increased, representing novel components that were previously not associated with sarcopenia. Tissue iron levels were elevated in senescence, paralleling an increase in transferrin. Proteins involved in redox homeostasis showed a complex pattern of changes with increased SOD1 and decreased SOD2. These results suggest that an elevated iron load is a significant component of sarcopenia with the potential to be exploited clinically, and that mitochondria of aged striated muscle may be more vulnerable to radicals produced in cell respiration. Muscle Nerve, 2007
Effects of aging on contact heat‐evoked potentials: The physiological assessment of thermal perception
Authors: Chao Chi‐Chao , Hsieh Sung‐Tsang , Chiu Ming‐Jang , Tseng Ming‐Tsung , Chang Yang‐Chyuan
Published: May 2007

Age significantly influences the detection thresholds to noxious heat; such thresholds depend on responses in the cerebral cortex to thermal stimuli and the psychophysical perception of such responses. To understand the influence of age on cerebral responses, we used contact heat‐evoked potentials (CHEPs) to investigate the physiology of cerebral responses to thermal stimuli in 70 healthy subjects (33 men and 37 women, 39.56 ± 12.12 years of age). With heat stimulation of fixed intensity (51°C) on the distal forearm and distal leg, CHEPs revealed consistent waveforms with an initial negative peak (N1 latency: 398.63 ± 28.55 and 449.03 ± 32.21 ms for upper and lower limbs) and a later positive peak (P1 latency: 541.63 ± 37.92 and 595.41 ± 39.24 ms for upper and lower limbs) with N1–P1 interpeak amplitude of 42.30 ± 12.57 μV in the upper limb and 39.67 ± 12.03 μV in the lower limb. On analyses with models of multiple linear regression, N1–P1 amplitudes were negatively correlated with age and N1 latencies were correlated with gender, with females having shorter latencies. The verbal rating scale (VRS) for pain perception was higher in females than males, and decreased with aging. In addition, VRS paralleled changes in N1–P1 amplitude and N1 latency; the higher the VRS, the shorter the N1 latency and the higher the N1–P1 amplitude. These results provide evidence that CHEPs are influenced significantly by aging, corresponding to aging‐related changes in thermal pain perception. Muscle Nerve, 2007
Measurement of cerebral perfusion territories using arterial spin labelling
Authors: Paiva Fernando F. , Tannús Alberto , Silva Afonso C.
Published: May 2007

The ability to assess the perfusion territories of major cerebral arteries can be a valuable asset to the diagnosis of a number of cerebrovascular diseases. Recently, several arterial spin labeling (ASL) techniques have been proposed for determining the cerebral perfusion territories of individual arteries by three different approaches: (1) using a dedicated labeling radio frequency (RF) coil; (2) applying selective inversion of spatially confined areas; (3) employing multidimensional RF pulses. Methods that use a separate labeling RF coil have high signal‐to‐noise ratio (SNR), low RF power deposition, and unrestricted three‐dimensional coverage, but are mostly limited to separation of the left and right circulation, and do require extra hardware, which may limit their implementation in clinical systems. Alternatively, methods that utilize selective inversion have higher flexibility of implementation and higher arterial selectivity, but suffer from imaging artifacts resulting from interference between the labeling slab and the volume of interest. The goal of this review is to provide the reader with a critical survey of the different ASL approaches proposed to date for determining cerebral perfusion territories, by discussing the relative advantages and disadvantages of each technique, so as to serve as a guide for future refinement of this promising methodology. Copyright © 2007 John Wiley & Sons, Ltd.
How Florida threw out the pork chop gang
Authors: Miller James Nathan
Published: May 2007

How the state legislature was revolutionized in less than a decade, from a “national joke” to a near standard of excellence for other state assemblies to follow.
A proactive management algorithm for self‐healing mobile ad hoc networks
Authors: Iskander Adel F. , Younis Akmal A.
Published: May 2007

The ability to proactively manage mobile ad hoc networks (MANETs) is critical for supporting complex services such as quality of service, security and access control in these networks. This paper focuses on the problem of managing highly dynamic and resource‐constrained MANET environments through the proposal of a novel proactive management algorithm (PMA) for self‐healing MANETs. PMA is based on an effective integration of autonomous, predictive and adaptive distributed management strategies. Proactive management is achieved through the distributed analysis of the current performance of the mobile nodes utilizing an optimistic discrete event simulation method, which is used to predict the mobile nodes' future status, and execution a proactive fault‐tolerant management scheme. PMA takes advantage of distributed parallel processing, flexibility and intelligence of active packets to minimize the management overhead, while adapting to the highly dynamic and resource‐constrained nature of MANETs. The performance of the proposed architecture is validated through analytical performance analysis and comparative simulation with the Active Virtual Network Management Protocol. The simulation results demonstrate that PMA not only significantly reduces management control overhead, but also improves both the performance and the stability of MANETs. Copyright © 2007 John Wiley & Sons, Ltd.
Using temporal correlation for fault localization in dynamically changing networks
Authors: Natu Maitreya , Sethi Adarshpal S.
Published: May 2007

A mobile ad hoc network creates a dynamic environment where node mobility can cause periodic changes in routes. Most existing fault localization algorithms assume availability of a complete and/or deterministic dependency model. Such assumptions cannot be made in the dynamically changing networks. This paper is aimed at developing a fault diagnosis architecture and algorithm to address the issue of dynamically changing dependencies in networks. We propose an architecture to capture the changes in dependencies and introduce a temporal correlation algorithm to perform fault diagnosis with the dynamically changing dependency information. We present an experimental evaluation of our work through simulation results using Qualnet. Copyright © 2007 John Wiley & Sons, Ltd.
Overexpression of the αvβ6 integrin in cervical squamous cell carcinoma is a prognostic factor for decreased survival
Authors: Hazelbag S , Kenter GG , Gorter A , Dreef EJ , Koopman LA , Violette SM , Weinreb PH , Fleuren GJ
Published: May 2007

Cervical squamous cell carcinomas are composed histologically of tumour cell islands surrounded by varying amounts of tumour stroma, the amount and composition of which are influenced by local TGF‐β1. TGF‐β1 is secreted in an inactive complex with latency‐associated peptide (LAP). Both LAP and the extracellular matrix (ECM) protein fibronectin are important ligands for the integrin receptor αvβ6. While αvβ6 is only weakly expressed by normal epithelia, it is up‐regulated in different carcinomas where it generally reflects a more aggressive phenotype. In cervical cancer, the expression of αvβ6 has not thus far been investigated. Given the ability of αvβ6 both to activate TGF‐β1 and to interact with fibronectin, we studied correlations between the expression of these components and disease parameters in a large cohort of cervical cancer specimens. We analysed αvβ6 expression using immunohistochemistry in primary cervical squamous carcinomas of FIGO stage IA to IIB patients and correlated the findings with formerly investigated fibronectin and TGF‐β1 expression and clinico‐pathological parameters. αvβ6 expression was also examined in cervical intra‐epithelial neoplasia (CIN) and lymph node metastases. αvβ6 was only weakly expressed in normal epithelium but clearly up‐regulated in CIN lesions. In carcinomas, strong expression of αvβ6 in tumour cells correlated with different clinico‐pathological parameters and with worse overall and disease‐free survival. Furthermore, αvβ6 expression correlated positively with TGF‐β1 mRNA expression as well as with fibronectin expression. Overexpression of αvβ6 in cervical squamous carcinomas is an unfavourable prognostic factor. This might reflect an increased capacity of αvβ6‐expressing tumour cells to migrate in a fibronectin‐rich ECM and/or to activate TGF‐β1 at the tumour/stroma interface, both of which processes may contribute to cervical cancer progression. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Neuropilins in physiological and pathological angiogenesis
Authors: Staton CA , Kumar I , Reed MWR , Brown NJ
Published: May 2007

Neuropilin‐1 (Np1) and neuropilin‐2 (Np2) are transmembrane glycoproteins with large extracellular domains that interact with both class 3 semaphorins and vascular endothelial growth factor (VEGF), and are involved in the regulation of many physiological pathways, including angiogenesis. The neuropilins also interact directly with the classical receptors for VEGF, VEGF‐R1 and ‐R2, mediating signal transduction. The heart, glomeruli and osteoblasts express both Np1 and Np2, but there is differential expression in the adult vasculature, with Np1 expressed mainly by arterial endothelium, whereas Np2 is only expressed by venous and lymphatic endothelium. Both neuropilins are commonly over‐expressed in regions of physiological (wound‐healing) and pathological (tumour) angiogenesis, but the signal transduction pathways, neuropilin‐mediated gene expression and the definitive role of neuropilins in angiogenic processes are not fully characterized. This review details the current evidence for the role of neuropilins in angiogenesis, and suggests future research directions that may enhance our understanding of the mechanisms of action of this unique family of proteins. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Prenatal ultrasound diagnosis of vasa praevia and analysis of risk factors
Authors: Baulies S. , Maiz N. , Muñoz A. , Torrents M. , Echevarría M. , Serra B.
Published: May 2007

Objective

To evaluate the role of ultrasound in prenatal diagnosis of vasa praevia (VP) and to asses the risk of VP associated with different causal factors.

Material and Methods

A retrospective study of the incidence of VP in a series of 12 063 deliveries between January 2000 and March 2005. We also studied the factors that predisposed for VP and the perinatal outcome of pregnancies.

Results

The prevalence of VP in our centre during this period was 0.07% (9 cases). All cases were prenatally diagnosed. The mean gestational age at diagnosis was 26 weeks. Multivariate analysis revealed the following associated factors: IVF pregnancies, bilobate or succenturiate placenta, and second‐trimester placenta praevia, with an odds ratio of 7.75, 22.11 and 22.86, respectively.

Conclusions

In our series, the prenatal diagnosis of all cases of VP achieved during the second‐trimester scan allowed us to avoid any prenatal death related to this condition. Copyright © 2007 John Wiley & Sons, Ltd.
Diagnosis of Apert syndrome in the second‐trimester using 2D and 3D ultrasound
Authors: David A. L. , Turnbull C. , Scott R. , Freeman J. , Bilardo C. M. , van Maarle M. , Chitty L. S.
Published: May 2007

Objectives

To illustrate how Apert syndrome, a rare autosomal dominant genetic syndrome, can be detected in the second‐trimester of pregnancy using 2D ultrasound, and how 3D ultrasound examination may provide parents with a better understanding of the structural defects affecting their baby.

Methods

Fetal Medicine Unit database searches to identify Apert syndrome cases.

Results

Five cases of Apert syndrome were suspected in the second‐trimester when sonography showed abnormal extremities including syndactyly, and an abnormal skull shape. In 1 case there was increased nuchal translucency with a normal fetal karyotype in the first‐trimester. In all cases, a mutation of the FGFR2 gene confirmed the diagnosis of Apert syndrome. 3D ultrasound was used to show parents the extent of the abnormalities of the skull, face and extremities. Parents were counseled by craniofacial surgeons and geneticists.

Conclusion

Apert syndrome can be accurately suspected in the second‐trimester by careful ultrasound examination of the fetus including the extremities and skull shape. 3D ultrasound can be a useful adjunct to 2D examination for parental counseling. Copyright © 2007 John Wiley & Sons, Ltd.
Star‐shaped alkylated poly(glycerol methacrylate) reverse micelles: Synthesis and evaluation of their solubilizing properties in dichloromethane
Authors: Gao Hui , Jones Marie‐Christine , Tewari Pankaj , Ranger Maxime , Leroux Jean‐Christophe
Published: May 2007

Amphiphilic star‐shaped polymers were synthesized by atom transfer radical polymerization (ATRP). Four‐, 5‐, and 6‐arm ATRP initiators were prepared and used to polymerize glycidylmethacrylate. The resulting polymers were hydrolyzed to yield poly(glycerolmethacrylate)s (PGOHMAs), and then partially esterified with lauroyl or stearoyl chloride (40–60 mol % vs. hydroxyl groups). Alkylated PGOHMAs were found to assemble into 20–60 nm aggregates in dichloromethane (DCM) above a critical concentration. Particle size essentially depended on the branching degree of the polymer. The micelles were extremely efficient in extracting Congo red from water into DCM, with the highest incorporations (97 mg/g) obtained for the 6‐arm polymer modified with stearoyl chloride (60 mol %). The entrapment efficiency for the latter was further improved in alkaline solution. The high level of incorporation achieved for these amphiphilic multiarm polymers suggests that such reverse micelles could be potentially useful as drug delivery systems and nanoreactors in catalytic organic reactions or for water purification. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2425–2435, 2007
Controlled photopolymerization reactions: The reactivity of new photoiniferters
Authors: Lalevée J. , El‐Roz M. , Allonas X. , Fouassier J. P.
Published: May 2007

Four new structures (o,o‐diethyl dithiobisthioformate, isopropylxanthic disulfide, tetramethyldicarbonotrithioic diamide, and phenylacetyl disulfide) are proposed as photoiniferters for controlled photopolymerization reactions. Their photochemical properties, efficiency in controlling the photopolymerization of methyl methacrylate (MMA), and ability to photocrosslink a difunctional acrylate monomer [1,6‐hexane diol diacrylate (HDDA)] are investigated. The rates of polymerization of MMA and HDDA and the number‐average molecular weights (Mn's) and polydispersity indices (PDIs) of poly(methyl methacrylate) have been determined. The transient absorption spectra and interaction rate constants of the radicals have been measured. Both the (alkyloxythiocarbonyl)thiyl and (benzylcarbonyl)thiyl radicals are efficient in controlling a photopolymerization process. For a 40% monomer conversion obtained in a few minutes, the Mn values range from 6000 to 14,000, and the PDIs can reach 1.6–2.2. A fivefold reduction of the light intensity increases Mn by 25% and reduces PDI by 5%. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2436–2442, 2007
Stereoregular P(MMA)‐clay nanocomposites by metallocene catalysts: In situ synthesis and stereocomplex formation
Authors: Mariott Wesley R. , Escudé Nicole C. , Chen Eugene Y.‐X.
Published: May 2007

This contribution reports the synthesis and characterization of stereochemically controlled, as well as crystalline stereocomplex, P(MMA)‐clay nanocomposites using metallocene complexes and alane‐intercalated clay activators. The ligand elimination and exchange reactions involving Lewis acids E(C6F5)3 (E = Al, B) and an organically modified montmorillonite clay were employed to synthesize the alane‐intercalated clay activators. When combined with dimethyl metallocenes of various symmetries, these clay activators brought about efficient MMA polymerizations leading to in situ polymerized, stereochemically controlled P(MMA)‐intercalated clay nanocomposites. The most noticeable thermal property enhancement observed for the clay nanocomposite P(MMA), when compared with the pristine P(MMA) having similar molecular weight and stereomicrostructure, has a considerable increase in Tg (≥10 °C). Mixing of dilute THF solutions of two diastereomeric nanocomposites in a 1:2 isotactic to syndiotactic ratio, followed by reprecipitation or crystallization procedures, yielded unique double‐stranded helical stereocomplex P(MMA)‐clay nanocomposites with a predominantly exfoliated clay morphology. Remarkably, the resulting crystalline stereocomplex P(MMA) matrix is resistant to the boiling‐THF extraction and its clay nanocomposites exhibit high Tm of 201 to 210 °C. Furthermore, the stereocomplex P(MMA)‐clay nanocomposite shows a one‐step, narrow decomposition temperature window and a single, high maximum rate decomposition temperature of 377 °C. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2581–2592, 2007
Detection of colorectal adenoma and cancer based on transthyretin and C3a‐desArg serum levels
Authors: Fentz Anne‐Kristin , Spörl Monika , Spangenberg Jörg , List Heinz Joachim , Zornig Carsten , Dörner Arnulf , Layer Peter , Juhl Hartmut , David Kerstin A.
Published: May 2007

Colorectal cancer is the second leading cause of cancer death, and it develops from benign colorectal adenomas in over 95% of patients. Early detection of these cancer precursors by screening tests and their removal can potentially eradicate more than 95% of colorectal cancers before they develop. To discover sensitive and specific biomarkers for improvement of pre‐clinical diagnosis of colorectal adenoma and cancer, we analysed in two independent studies (n = 87 and n = 83 patients) serum samples from colorectal cancer (stage III), colorectal adenoma and control patients using SELDI‐TOF‐MS. Extensive statistical analysis was performed to establish homogeneous patient groups based on their clinical data. Two biomarkers that were each able to distinguish control patients from either colorectal adenoma or colorectal cancer patients (p<0.001) were identified as transthyretin (pre‐albumin) and C3a‐desArg by MS/MS and were further validated by antibody‐based assays (radial immunodiffusion, ELISA). A combination of both proteins clearly indicated the presence of colorectal adenoma or carcinoma. Using a cut‐off of <0.225 g/L for transthyretin and >1974 ng/mL for C3a‐desArg, we found a sensitivity and specificity for colorectal adenoma of 96% and 70%, respectively.