bluuebunny/crossref_metadata_2025 huggingface dataset:
Hippocampal mitochondrial dysfunction in rat aging
Authors: Navarro Ana , López-Cepero José M. , Bández Manuel J. , Sánchez-Pino María-Jesús , Gómez Carmen , Cadenas Enrique , Boveris Alberto
Published: December 2007

Hippocampus mitochondrial dysfunction with impaired electron transfer and increased oxidative damage was observed upon rat aging. Hippocampal mitochondria of aged (12 mo) and senescent (20 mo) rats showed, compared with young (4 mo) rats, marked decreases in the rate of state 3 respiration with NAD-dependent substrates (32–51%) and in the activities of mitochondrial complexes I (57–73%) and IV (33–54%). The activity of mitochondrial nitric oxide synthase was also decreased, 53–66%, with age. These losses in enzymatic activity were more marked in the hippocampus than in brain cortex or in whole brain. The histochemical assay of mitochondrial complex IV in the hippocampus showed decreased staining upon aging. Oxidative damage, determined as the mitochondrial content of thiobarbituric-acid reactive substances (TBARS) and protein carbonyls, increased in aged and senescent hippocampus (66–74% in TBARS and 48–96% in carbonyls). A significant statistical correlation was observed between mitochondrial oxidative damage and enzymatic activity. Mitochondrial dysfunction with shortage of energy supply is considered a likely cause of dysfunction in aged hippocampus.
Amelioration of anti-Thy1-glomerulonephritis by PPAR-γ agonism without increase of endothelial progenitor cell homing
Authors: Westerweel Peter E. , den Ouden Krista , Nguyen Tri Q. , Goldschmeding Roel , Joles Jaap A. , Verhaar Marianne C.
Published: December 2007

Impaired glomerular endothelial integrity is pivotal in various renal diseases and depends on both the degree of glomerular endothelial injury and the effectiveness of glomerular endothelial repair. Glomerular endothelial repair is, in part, mediated by bone marrow-derived endothelial progenitor cells. Peroxisome proliferator activated receptor-γ (PPAR-γ) agonists have therapeutic actions independent of their insulin-sensitizing effects, including enhancement of endothelial progenitor cell function and differentiation. We evaluated the effect of PPAR-γ agonist rosiglitazone (4 mg·kg−1·day−1) on the course of anti-Thy1-glomerulonephritis in rats. Rosiglitazone limited the development of proteinuria and prevented plasma urea elevation (8.1 ± 0.4 vs. 12.5 ± 1.1 mmol/l, P = 0.002). Histologically, inflammatory cell influx was not affected, but rosiglitazone-treated rats did show fewer microaneurysmatic glomeruli on day 7 (26 ± 3 vs. 41 ± 5%, P = 0.01) and reduced activation of matrix production with reduced renal cortical transforming growth factor-β, plasminogen activator inhibitor type 1, and fibronectin-1 mRNA expression. However, bone marrow-derived endothelial cell glomerular incorporation was not enhanced (3.1 ± 0.4 vs. 3.6 ± 0.3 cells/glomerular cross section; P = 0.31). Rosiglitazone treatment in nonnephritic rats did not influence proteinuria, urea, or renal histology. In conclusion, treatment with PPAR-γ agonist rosiglitazone ameliorates the course of experimental glomerulonephritis in a nondiabetic model, but not through enhancing incorporation of bone marrow-derived endothelial cells in the glomerulus.
Effect of weight loss on lactate transporter expression in skeletal muscle of obese subjects
Authors: Metz Lore , Mercier Jacques , Tremblay Angelo , Alméras Natalie , Joanisse Denis R.
Published: December 2007

The effects of weight loss on skeletal muscle lactate transporter [monocarboxylate transporter (MCT)] expression in obese subjects were investigated to better understand how lactate transporter metabolism is regulated in insulin-resistant states. Ten obese subjects underwent non-macronutrient-specific energy restriction for 15 wk. Anthropometric measurements and a needle biopsy of the vastus lateralis muscle before and after the weight loss program were performed. Enzymatic activity, fiber type distribution, and skeletal muscle MCT protein expression were measured. Muscle from nonobese control subjects was used for comparison of MCT levels. The program induced a weight loss of 9.2 ± 1.6 kg. Compared with controls, muscle from obese subjects showed a strong tendency ( P = 0.06) for elevated MCT4 expression (+69%) before the weight loss program. MCT4 expression decreased (−7%) following weight loss to reach levels that were not statistically different from control levels. There were no differences in MCT1 expression between controls and obese subjects before and after weight loss. A highly predictive regression model ( R2= 0.93), including waist circumference, citrate synthase activity, and percentage of type 1 fibers, was found to explain the highly variable MCT1 response to weight loss in the obese group. Therefore, in obesity, MCT1 expression appears linked both to changes in oxidative parameters and to changes in visceral adipose tissue content. The strong tendency for elevated expression of muscle MCT4 could reflect the need to release greater amounts of muscle lactate in the obese state, a situation that would be normalized with weight loss as indicated by decreased MCT4 levels.
Effect of Vertical Disparities on Depth Representation in Macaque Monkeys: MT Physiology and Behavior
Authors: Chowdhury Syed A. , Christiansen Daniel L. , Morgan Michael L. , DeAngelis Gregory C.
Published: December 2007

Horizontal binocular disparities provide information about the distance of objects relative to the point of ocular fixation and must be combined with an estimate of viewing distance to recover the egocentric distance of an object. Vergence angle and the gradient of vertical disparities across the visual field are thought to provide independent sources of viewing distance information based on human behavioral studies. Although the effect of vergence angle on horizontal disparity selectivity in early visual cortex has been examined (with mixed results), the effect of the vertical disparity field has not been explored. We manipulated the vertical disparities in a large random-dot stimulus to simulate different viewing distances, and we examined the effect of this manipulation on both the responses of neurons in the middle temporal (MT) area and on the psychophysical performance of the animal in a curvature discrimination task. We report here that alterations to the vertical disparity field have no effect on the horizontal disparity tuning of MT neurons. However, the same manipulation strongly and systematically biases the monkey's judgments of curvature, consistent with previous human studies. We conclude that monkeys, like humans, make use of the vertical disparity field to estimate viewing distance, but that the physiological mechanisms for this effect occur either downstream of MT or in a different pathway.
A Framework to Support Automated Classification and Labeling of Brain Electromagnetic Patterns
Authors: Frishkoff Gwen A. , Frank Robert M. , Rong Jiawei , Dou Dejing , Dien Joseph , Halderman Laura K.
Published: December 2007

This paper describes a framework for automated classification and labeling of patterns in electroencephalographic (EEG) and magnetoencephalographic (MEG) data. We describe recent progress on four goals: 1) specification of rules and concepts that capture expert knowledge of event-related potentials (ERP) patterns in visual word recognition; 2) implementation of rules in an automated data processing and labeling stream; 3) data mining techniques that lead to refinement of rules; and 4) iterative steps towards system evaluation and optimization. This process combines top-down, or knowledge-driven, methods with bottom-up, or data-driven, methods. As illustrated here, these methods are complementary and can lead to development of tools for pattern classification and labeling that are robust and conceptually transparent to researchers. The present application focuses on patterns in averaged EEG (ERP) data. We also describe efforts to extend our methods to represent patterns in MEG data, as well as EM patterns in source (anatomical) space. The broader aim of this work is to design an ontology-based system to support cross-laboratory, cross-paradigm, and cross-modal integration of brain functional data. Tools developed for this project are implemented in MATLAB and are freely available on request.
Precoded DOSTBC over Rayleigh Channels
Authors: Bhatnagar Manav R. , Hjørungnes Are , Song Lingyang
Published: December 2007

Differential orthogonal space-time block codes (DOSTBC) sent over correlated Rayleigh fading channels are considered in this paper. Approximate expressions for the symbol error rate (SER) are derived for DOSTBC withM-PSK,M-PAM, andM-QAM constellations assuming arbitrary correlation between the transmit and receive antennas. A full memoryless precoder is designed to improve the performance of the DOSTBC over correlated Rayleigh MIMO channels. The proposed precoder design differs from the previous work: (1) our precoder design considers arbitrary correlation in the channels, whereas the previously proposed precoder design considers only transmit correlations in the Kronecker correlation model; (2) the proposed precoder is based on minimizing proposed SER, whereas the previously proposed precoder is based on minimizing the Chernoff bound of approximate SER; (3) we propose precoder design for DOSTBC withM-PSK,M-PAM, andM-QAM constellations, whereas the previously proposed precoder works for DOSTBC withM-PSK only. Additionally, the proposed precoded DOSTBC outperforms the conventional eigenbeamforming-based precoded DOSTBC for the Kronecker model with only transmit correlation.
Evolving Ecological Social Dilemmas: A Spatial Individual-Based Model for the Evolution of Cooperation with a Minimal Number of Parameters
Authors: Fort H.
Published: December 2007

Cooperation, both intraspecific and interspecific, is a well-documented phenomenon in nature that is not well understood. Evolutionary game theory is a powerful tool to approach this problem. However, it has important limitations. First, very often it is not obvious which game is more appropriate to use. Second, in general, identical payoff matrices are assumed for all players, a situation that is highly unlikely in nature. Third, slight changes in these payoff values can dramatically alter the outcomes. Here, I use an evolutionary spatial model in which players do not have a universal payoff matrix, so no payoff parameters are required. Instead, each is equipped with random values for the payoffs, fulfilling the constraints that define the game(s). These payoff matrices evolve by natural selection. Two versions of this model are studied. First is a simpler one, with just one evolving payoff. Second is the “full” version, with all the four payoffs evolving. The fraction of cooperator agents converges in both versions to nonzero values. In the case of the full version, the initial heterogeneity disappears and the selected game is the “Stag Hunt.”
Cytokine Release in HR-HPV(+) Women without and with Cervical Dysplasia (CIN II and III) or Carcinoma, Compared with HR-HPV(−) Controls
Authors: Bais Aagje G. , Beckmann Ilse , Ewing Patricia C. , Eijkemans Marinus J. C. , Meijer Chris J. L. M. , Snijders Peter J. F. , Helmerhorst Theo J. M.
Published: December 2007

Aims. We investigated the effect of HR-HPV infection on the capacity of the cytokine network in whole blood cultures during carcinogenesis of cervical carcinoma.Methods. Thirty-nine women with moderate dysplasia, severe dysplasia, cervical carcinoma, or without dysplasia formed the study group. The control group consisted of 10 HR-HPV-negative women without CIN. Whole blood cultures were stimulated with phytohemagglutinin (PHA) and concentrations of tumour necrosis factorα(TNFα), interferonγ(IFNγ), interleukin 2 (IL-2), interleukin 12 (IL-12), interleukin 4 (IL-4), and interleukin 10 (IL-10) were determined by ELISAs.Results. A significant increase in cytokine release was detected in HR-HPV-positive women without dysplasia. In women with cervical cancer, release of IFNγand IL-12 was of the same magnitude as in HR-HPV-positive women without clinical manifestations. Most Th1-type/Th2-type ratios decreased form CIN II to CIN III, and increased from CIN III to invasive carcinoma.Conclusions. (1) Infection with HR-HPV without expression of cervical dysplasia induces activation of the cytokine network. (2) Increases in ratios of Th1-type to Th2-type cytokines at the stage of cervical carcinoma were found by comparison with stage CIN III. (3) Significant changes in the kinetics of cytokine release to a Th2-type immune response in blood of women with cervical dysplasia occurred progressively from CIN II to CIN III.
RF Power and Thermal Annealing Effect on the Properties of Zinc Oxide Films Prepared by Radio Frequency Magnetron Sputtering
Authors: Li Chaoyang , Furuta Mamoru , Matsuda Tokiyoshi , Hiramatsu Takahiro , Furuta Hiroshi , Hirao Takashi
Published: December 2007

Polycrystalline zinc oxide (ZnO) films were prepared by radio frequency (RF) magnetron sputtering under different powers. The XRD results showed that ZnO crystallite size along c-axis decreased by 43% with deposition power increased from 60 W to 300 W, increased 36% with annealing temperature rising to400∘C. TDS measurement revealed that the desorption peaks of both atomic Zn (60 W-deposited) and oxygen molecule (180 W and 300 W-deposited) obtained from ZnO films were originated from300∘C. When annealing temperature was higher than300∘C, the sheet resistance dramatically decreased, and compressive stress in the (002) plane changed to tensile stress as well. The comparison measurements of ZnO films crystallinity strongly suggested that both lower deposition power and certain thermal annealing temperature over300∘Cwould contribute to the formation of high quality ZnO films.
Electronic Properties ofNdOs4Sb12
Authors: Galvan Donald H.
Published: December 2007

Theoretical calculations onNdOs4Sb12-filled skutterudite are reported. The calculated energy bands yield indication of a semimetallic behavior, while the projected density of states provides support for the existence of hybridization formed by Nd f-, Os d-, and Sb p-states.
The Implicit Function as Squashing Time Model: A Novel Parallel Nonlinear EEG Analysis Technique Distinguishing Mild Cognitive Impairment and Alzheimer's Disease Subjects with High Degree of Accuracy
Authors: Buscema Massimo , Capriotti Massimiliano , Bergami Francesca , Babiloni Claudio , Rossini Paolo , Grossi Enzo
Published: December 2007

Objective. This paper presents the results obtained using a protocol based on special types of artificial neural networks (ANNs) assembled in a novel methodology able to compress the temporal sequence of electroencephalographic (EEG) data into spatial invariants for the automatic classification of mild cognitive impairment (MCI) and Alzheimer's disease (AD) subjects. With reference to the procedure reported in our previous study (2007), this protocol includes a new type of artificial organism, named TWIST. The working hypothesis was that compared to the results presented by the workgroup (2007); the new artificial organism TWIST could produce a better classification between AD and MCI.Material and methods. Resting eyes-closed EEG data were recorded in 180 AD patients and in 115 MCI subjects. The data inputs for the classification, instead of being the EEG data, were the weights of the connections within a nonlinear autoassociative ANN trained to generate the recorded data. The most relevant features were selected and coincidently the datasets were split in the two halves for the final binary classification (training and testing) performed by a supervised ANN.Results. The best results distinguishing between AD and MCI were equal to 94.10% and they are considerable better than the ones reported in our previous study (∼92%) (2007).Conclusion. The results confirm the working hypothesis that a correct automatic classification of MCI and AD subjects can be obtained by extracting spatial information content of the resting EEG voltage by ANNs and represent the basis for research aimed at integrating spatial and temporal information content of the EEG.
Three-Input Single-Output Electronically Controllable Dual-Mode Universal Biquad Filter Using DO-CCCIIs
Authors: Siripruchyanun M. , Jaikla W.
Published: December 2007

This article presents a dual-mode (voltage-mode and current-mode) universal biquadratic filter performing completely standard functions: lowpass, highpass, bandpass, band-reject, and allpass functions, based on plus-type dual-output second-generation, current controlled, current conveyor (DO-CCCII+). The features of the circuit are that the bandwidth and natural frequency can be tuned electronically via the input bias currents: the circuit description is very simple, consisting of merely 2 DO-CCCIIs and 2 capacitors: the circuit can provide either the voltage-mode or current-mode filter without changing circuit topology. Additionally, each function response can be selected by suitably selecting input signals with digital method. Without any external resistors, the proposed circuit is very suitable to further develop into an integrated circuit. The PSPICE simulation results are depicted. The given results agree well with the theoretical anticipation. The maximum power consumption is approximately 1.81 mW at±1.5 V supply voltages.
Multifunctional Composites Obtained by Incorporating Nanocrystals into Decorated PVK Polymers
Authors: Sun Haizhu , Zhang Junhu , Tian Ye , Ning Yang , Zhang Hao , Ju Jie , Li Delong , Xiang Shidong , Yang Bai
Published: December 2007

Poly(vinylcarbazole) (PVK) was decorated with surfactant group to achieve amphiphilic polymer with luminescent property. The composition and properties of the polymers were systematically investigated using FTIR, EA, TGA, UV-Vis, and PL characterizations. Different CdTe nanocrystals (NCs) prepared in aqueous medium were directly transferred to organic phase using the PVK-based polymers. The quantum yield of NCs in the composites had been improved by 50% compared with their parent aqueous solution due to the short distance from carbazole moieties to NCs, which facilitated the Förster resonant energy transfer (FRET) between them. Moreover, efficient electron transfer at the interface of NCs and polymers had been confirmed which also indicated the application in photovoltaic cell for such composites.
Effects of Microstructure Variations on Macroscopic Terahertz Metafilm Properties
Authors: O'Hara John F. , Smirnova Evgenya , Azad Abul K. , Chen Hou-Tong , Taylor Antoinette J.
Published: December 2007

The properties of planar, single-layer metamaterials, or metafilms, are studied by varying the structural components of the split-ring resonators used to comprise the overall medium. Measurements and simulations reveal how minor design variations in split-ring resonator structures can result in significant changes in the macroscopic properties of the metafilm. A transmission-line/circuit model is also used to clarify some of the behavior and design limitations of the metafilms. Though our results are illustrated in the terahertz frequency range, the work has broader implications, particularly with respect to filtering, modulation, and switching devices.
Generation and Screening of a BAC Library from a Diploid Potato Clone to Unravel Durable Late Blight Resistance on Linkage Group IV
Authors: Hein Ingo , McLean Karen , Chalhoub Boulos , Bryan Glenn J.
Published: December 2007

We describe the construction and screening of a large insert genomic library from the diploid potato clone HB171(13) that has been shown to express durable quantitative field resistance toPhytophthora infestans, the causal agent of potato late blight disease. Integrated genetic mapping of the field resistance quantitative trait locus with markers developed from populations segregating forRpi-blb3, Rpi-abpt,R2, andR2-like resistance, all located on linkage group IV, has positioned the field resistance QTL within the proximity of thisRgene cluster. The library has been successfully screened with resistance gene analogues (RGA) potentially linked to theRgene cluster. Over 30 positive BAC clones were identified and confirmed by PCR and Southern hybridisations to harbour RGA-like sequences. In addition, BAC end sequencing of positive clones has corroborated two BAC clones with a very high level of nucleotide similarity to the RGA probes utilised.
Compact Optical Waveguides Based on Hybrid Index and Surface-Plasmon-Polariton Guidance Mechanisms
Authors: Yan Min , Qiu Min
Published: December 2007

Surface-plasmon-polariton (SPP) waveguides made of materials available in nature have, in general, been found to suffer from very high absorption loss when light confinement is beyond diffraction limit. In this paper, the possibility of combining both the conventional index-guiding and the SPP-guiding mechanisms together into one single waveguide is being explored. Such waveguides, expectedly, inherent the low-loss feature of all-dielectric waveguides as well as the superior mode field confinement possessed by SPP waveguides. By using experimentally ready materials, it is theoretically shown that compact metallodielectric waveguides can be designed with a∼500×500 nm2core size around the 1550 nm telecommunication wavelength. The examined waveguides can be interpreted as a gap SPP waveguide with an inner dielectric core. Compared to pure SPP waveguides, such hybrid waveguides have a comparable mode field size, but with significantly lower loss (∼0.05 dB/μmfor either quasi-TE or quasi-TM operation). Therefore they can be potentially deployed for a range of integrated photonic applications.
The Possible Correlation between the Patient's Immune Tolerance Level During Cesaerean Section and the Incidence of Subsequent Emergency Peripartum Hysterectomy
Authors: Wicherek Lukasz , Galazka Krystna
Published: December 2007

Introduction. Cesarean section is an independent risk factor for peripartum hysterectomy. As a method of delivery, cesarean section may interfere with a number of molecular changes that occur at the maternal-fetal interface during the course of labor.Methods. The level of CD3, CD56, CD25, and CD69 antigen immunoreactivity was assessed by immunohistochemistry in 26 decidual tissue samples. The tissue samples were obtained from 18 women who underwent cesarean sections at term and from 8 women who underwent cesarean hysterectomies.Results. An increase in the activity and infiltration of immune cells in the decidua sampled during the spontaneous beginning of labor was observed. The further progression of labor was accompanied by a decrease in the number and activity of immune cells. The number of CD56+ and CD3+ cells in the decidua was statistically significantly lower in patients who had undergone cesarean hysterectomies than in those who had had cesarean sections at term.Conclusion. Abnormal immune response during labor may increase the risk for peripartum hysterectomy.
Application of Blind Deblurring Reconstruction Technique to SPECT Imaging
Authors: Li Heng , Zheng Yibin
Published: December 2007

An SPECT image can be approximated as the convolution of the ground truth spatial radioactivity with the system point spread function (PSF). The PSF of an SPECT system is determined by the combined effect of several factors, including the gamma camera PSF, scattering, attenuation, and collimator response. It is hard to determine the SPECT system PSF analytically, although it may be measured experimentally. We formulated a blind deblurring reconstruction algorithm to estimate both the spatial radioactivity distribution and the system PSF from the set of blurred projection images. The algorithm imposes certain spatial‐frequency domain constraints on the reconstruction volume and the PSF and does
not otherwise assume knowledge of the PSF. The algorithm alternates between two iterative update sequences that correspond to the PSF and radioactivity estimations, respectively. In simulations and a small‐animal study, the algorithm reduced image blurring and preserved the edges without introducing extra artifacts. The localized measurement shows that the reconstruction efficiency of SPECT images improved more than 50% compared to conventional expectation maximization (EM) reconstruction. In experimental studies, the contrast and quality of reconstruction was substantially
improved with the blind deblurring reconstruction algorithm.
Discrete Stochastic Dynamics of Income Inequality in Education: An Applied Stochastic Model and a Case Study
Authors: Kara Ahmet
Published: December 2007

This paper develops a model for the discrete stochastic dynamics of economic inequality-induced outcomes in education and demonstrates, in the context of the Turkish higher education sector, that higher incomes lead to higher performance levels; and hence income inequality matters. The paper formulates a stochastic subsidy policy that could help the sector to escape the low performance equilibria, and that could stabilize the sector at relatively higher performance levels.
Blurring Borders: Innate Immunity with Adaptive Features
Authors: Kvell K. , Cooper EL. , Engelmann P. , Bovari J. , Nemeth P.
Published: December 2007

Adaptive immunity has often been considered the penultimate of immune capacities. That system is now being deconstructed to encompass less stringent rules that govern its initiation, actual effector activity, and ambivalent results. Expanding the repertoire of innate immunity found in all invertebrates has greatly facilitated the relaxation of convictions concerning what actually constitutes innate and adaptive immunity. Two animal models, incidentally not on the line of chordate evolution (C. elegansandDrosophila), have contributed enormously to defining homology. The characteristics of specificity and memory and whether the antigen is pathogenic or nonpathogenic reveal considerable information on homology, thus deconstructing the more fundamentalist view. Senescence, cancer, and immunosuppression often associated with mammals that possess both innate and adaptive immunity also exist in invertebrates that only possess innate immunity. Strict definitions become blurred casting skepticism on the utility of creating rigid definitions of what innate and adaptive immunity are without considering overlaps.
Determining the Optimum Tilt Angle and Orientation for Solar Energy Collection Based on Measured Solar Radiance Data
Authors: Li Danny H. W. , Lam Tony N. T.
Published: December 2007

A prior requirement to the design of any solar-based conversion systems is the knowledge of optimum orientation and tilt surface at which peak solar energy can be collected. In many parts of the world, however, the solar radiation data for the surfaces of interest are not always available. This paper presents a numerical approach to calculate the solar radiation on sloped planes by integrating the measured sky radiance distributions. The annual total solar yield at different sloped surfaces facing various orientations and monthly solar radiations at the optimal tilt surface and three vertical planes facing east, south, and west were determined. The energy outputs and efficiencies were simulated using a computer package. The environmental benefits in terms of greenhouse gases reductions and cost implications were also considered. The findings provide technical information for engineers to design and evaluate photovoltaic (PV) systems which could contribute to the environmental, energy, and economic aspects.
Lead-Cooled Fast Reactor Systems and the Fuels and Materials Challenges
Authors: Allen T. R. , Crawford D. C.
Published: December 2007

Anticipated developments in the consumer energy market have led developers of nuclear energy concepts to consider how innovations in energy technology can be adapted to meet consumer needs. Properties of molten lead or lead-bismuth alloy coolants in lead-cooled fast reactor (LFR) systems offer potential advantages for reactors with passive safety characteristics, modular deployment, and fuel cycle flexibility. In addition to realizing those engineering objectives, the feasibility of such systems will rest on development or selection of fuels and materials suitable for use with corrosive lead or lead-bismuth. Three proposed LFR systems, with varying levels of concept maturity, are described to illustrate their associated fuels and materials challenges. Nitride fuels are generally favored for LFR use over metal or oxide fuels due to their compatibility with molten lead and lead-bismuth, in addition to their high atomic density and thermal conductivity. Ferritic/martensitic stainless steels, perhaps with silicon and/or oxide-dispersion additions for enhanced coolant compatibility and improved high-temperature strength, might prove sufficient for low-to-moderate-temperature LFRs, but it appears that ceramics or refractory metal alloys will be necessary for higher-temperature LFR systems intended for production of hydrogen energy carriers.
PPAR Signaling in Placental Development and Function
Authors: Barak Yaacov , Sadovsky Yoel , Shalom-Barak Tali
Published: December 2007

With the major attention to the pivotal roles of PPARs in diverse aspects of energy metabolism, the essential functions of PPARγ and PPARβ/δ in placental development came as a surprise and were often considered a nuisance en route to their genetic analysis. However, these findings provided an opportune entrée into placental biology. Genetic and pharmacological studies, primarily of knockout animal models and cell culture, uncovered networks of PPARγ and PPARδ, their heterodimeric RXR partners, associated transcriptional coactivators, and target genes, that regulate various aspects of placental development and function. These studies furnish both specific information about trophoblasts and the placenta and potential hints about the functions of PPARs in other tissues and cell types. They reveal that the remarkable versatility of PPARs extends beyond the orchestration of metabolism to the regulation of cellular differentiation, tissue development, and trophoblast‐specific functions. This information and its implications are the subject of this review.
Reduction of Time‐Dependent Schrödinger Equations with Effective Mass to Stationary Schrödinger Equations
Authors: Schulze-Halberg Axel
Published: December 2007

We introduce a class of potentials for which the time‐dependent Schrödinger equation with
position‐dependent (effective) mass allows reduction to a stationary Schrödinger equation.
This reduction is done by a particular point canonical transformation which preserves L2‐normalizability.
Ethical and Legal Implications in Seeking and Providing a Second Medical Opinion
Authors: Axon Anthony , Hassan Majid , Niv Yaron , Beglinger Christoph , Rokkas Theodore
Published: December 2007

Ethical and legal implications arise both when seeking a second medical opinion and when providing one. There has been debate as to whether a second opinion for a patient is a right or a concession and whilst today most would consider it to be a patient’s right, there are nevertheless some disadvantages associated with seeking a second opinion. This article addresses the reasons why patients seek second opinions, it considers when physicians themselves should refer patients and it covers the issues involved in providing a second opinion particularly in cases where there is the potential for an allegation of malpractice. Finally, the arguments for and against treating patients who are referred for a second opinion are addressed. This paper has been prepared following a round table discussion on this subject, which was addressed during a symposium on Ethics in Gastroenterology and Digestive Endoscopy held in Kos in 2006.
Ethical Aspects of Capsule Endoscopy
Authors: Niv Yaron
Published: December 2007

Capsule endoscopy is the most recent innovation in gastrointestinal endoscopy. The capsule contains a video camera that photographs the bowel for 8 h after the capsule has been orally ingested and transmits the images for interpretation to a computerized workstation. Ethical considerations of the use of capsule endoscopy should cover the following main issues: justification of the procedure, its potential benefits and harm, and patient autonomy. Capsule endoscopy has several advantages over traditional endoscopy. The procedure is painless, does not require sedation, is easy to perform and for the first time enables exploration of the entire small bowel at high magnification. However, the clinician cannot control its passive advance along the bowel. In addition, the examination may be incomplete, as the capsule reaches the cecum in only 80% of cases. This paper discusses the problems related to the new endoscopic procedure, the diagnostic yield in comparison with other procedures, proper indications for the procedure, outcome and complications.
Informed Consent and the Law – An English Legal Perspective
Authors: Hassan Majid
Published: December 2007

‘Informed consent’ is a widely used term, but its application in a legal perspective can be varied. American and Commonwealth jurisdictions have developed a ‘patient-based’ true informed consent approach, whereas in the English legal system a ‘doctor-based’ approach has traditionally been applied in relation to disclosure of risk. This article will seek to compare these approaches and give a brief overview of some of the key legal rulings which have shaped the requirement of consent. The decision in the English case of Chester vs. Afshar is considered as showing the significance the court attached to the principle of autonomy and using ethical and policy considerations to depart from established principles of English law relating to consent to treatment and disclosure of risk. This review is intended as general information and not as legal advice which should be sought from defence organisation and specialist health care lawyers.
Ethics Related to Drug Therapy in the Elderly
Authors: Beglinger Christoph
Published: December 2007

Adverse drug events are common, especially in risk groups such as elderly persons. Many of the adverse drug events are preventable. The age-related changes in the different body functions have an impact on drug therapy: adjustments are required for the selection of drugs and dosages in elderly patients. Kidney function declines with age; as a consequence, drug excretion via the kidneys declines with increasing age. Also, the metabolic clearance of drugs that display a high hepatic extraction is reduced in elderly persons and the dosage of these drugs should be adapted. The present review summarizes the main findings related to the topic. Human beings make errors. Ensuring patient safety is a key issue. For elderly patients more information is required to establish a solid knowledge base. It is therefore necessary to include elderly patients in appropriate clinical trials in order to ensure that the necessary information can be accumulated.
Intragastric Balloon: Ethics, Medical Need and Cosmetics
Authors: Kotzampassi Katerina , Shrewsbury Anne D.
Published: December 2007

The development of the intragastic balloon as a safe, noninvasive, alternative method to weight reduction raises all the ethical questions routinely faced by practitioners of other forms of cosmetic surgery. In the case of the morbidly, severely or merely obese, the surgeon is faced with a medical decision in a situation defined by medical parameters. The case of the overweight or normal may, however, create an ethical dilemma in which the doctor is forced to make decisions of a nonmedical nature, for which his training has not prepared him, and relating essentially to his personal attitudes and moral beliefs, culture and the recognition that ‘if I don’t, somebody else – possibly less competent – will’.
Do We Present Abstracts on Ethical, Legal, Cost-Effectiveness and Patient Care Issues at Major Gastroenterology Congresses?
Authors: Archavlis E. , Triantafyllou K. , Adamopoulos A. , Emmanuel T. , Tzathas C. , Ladas S.D.
Published: December 2007

Introduction: In the era of the new millennium, a lot of preclinical and clinical research is published. However, ethico-legal, cost-effectiveness and patient care issues are not addressed equally. Aim: To investigate whether abstracts presented at major international gastroenterology congresses refer to issues relevant to doctor-patient relationship, cost-effectiveness and care. Methods: We reviewed the abstracts on disk CD-ROMs of the United European Gastroenterology Week (UEGW) and the Digestive Disease Week (DDW), for the years 1998–2006. We used the following keywords: ethical/ethically, legal, consent, cost-effective/effectiveness, care, quality and tolerable/tolerability. Results: Over the study period, 1,612/20,018 (8.05%) and 764/45,628 (1.67%) abstracts including the above keywords were presented at UEGW and DDW congresses (p = 0.013), respectively. Statistically significant more abstracts containing separately any of the key words (apart from ‘legal’) were presented at the UEGW than at the DDW congress. There was a significant trend of increased referring to these key words over the study period for UEGW (p < 0.041) but not for DDW congresses (p = 0.70). Conclusion: The abstracts presented at the UEGW refer to ethico-legal, cost-effectiveness and patient care issues more frequently than those presented at the DDW. There is a trend of increased referring to these subjects at the UEGW but not at the DDW.
Patient Satisfaction with Endoscopy Measurement and Assessment
Authors: Yanai H. , Schushan-Eisen I. , Neuman S. , Novis B.
Published: December 2007

Background: Several factors could influence patient satisfaction with endoscopy including technical quality of care, comfort and tolerability of the procedure, whether informed consent has been obtained, the level of communication with staff before and after the procedure, and delays in appointments. Aim: To assess what factors should be measured in assessing patient satisfaction by using a 16-point questionnaire based on the informed consent recommendations of the first workshop at Kos, and of the criteria of the American Society for Gastrointestinal Endoscopy (ASGE), and to compare the response of patients with gastroenterologists and the support staff. Method: The questionnaire was answered by 81 patients, 71 gastroenterologists and 36 support staff (nurses and receptionists). It graded the relative importance of different factors which influenced the perception of satisfaction in those undergoing endoscopy. These factors included: the waiting time for appointment, the explanation received at various stages before and after the procedure, the reception process, the importance of premedication against pain and discomfort, privacy and satisfaction related to findings at the procedure. Results: Thirteen of the 16 factors were generally graded as important for patient satisfaction. The finding at endoscopy, a written explanation and the alternatives to the endoscopic procedure were regarded as of lesser importance. Gastroenterologists tended to rate the importance of a written explanation and the explanations from the nurses before and after the procedure lower than did the patients and nursing staff. Conclusions: The courtesy and personal manner of the entire medical staff, as evidenced by the explanation of the procedure by the various physicians before and after and the process of admission, were generally rated of the highest importance. The nurses’ ranking of the various factors was closer to that of the patients than of the gastroenterologists.
Microdeletions in 9p21.3 induce false negative results in CDKN2A FISH analysis of Ewing sarcoma
Authors: Savola S. , Nardi F. , Scotlandi K. , Picci P. , Knuutila S.
Published: December 2007

Deletion of the CDKN2A locus at 9p21.3 has been reported to be a poor prognostic sign in the Ewing sarcoma family of tumours. In clinical applications CDKN2A deletion is primarily detected using fluorescent in situ hybridisation (FISH) with a commercial probe, size ∼190 kb. Due to limitations in resolution, FISH analysis may fail to detect microdeletions smaller than 190 kb. In the present study, we performed 44K array comparative genomic hybridisation (CGH) on eleven Ewing sarcoma cell lines and 26 tissue samples in order to define the sizes of 9p21.3 deletions. Microarray CGH analysis revealed 9p21.3 deletions encompassing the CDKN2A locus in eight cell lines (73%) and in six tumours (23%). In four cases (two cell lines and two tissue samples) the deletion was less than 190 kb in size. In one cell line sample, we detected a microdeletion of ∼58 kb in 9p21.3 harbouring the CDKN2A locus. We confirmed this result using 244K microarray CGH and TaqMan quantitative RT-PCR analysis and further performed FISH analysis on this cell line sample. Here, we show that CDKN2A FISH analysis can give false negative results in cases with small microdeletions. Our results suggest that new and more accurate FISH methods should be developed for detection of deletions in the CDKN2A locus.
Oligonucleotide array comparative genomic hybridization refines the structure of 8p23.1, 17q12 and 20q13.2 amplifications in gastric carcinomas
Authors: Vauhkonen H. , Vauhkonen M. , Sipponen P. , Knuutila S.
Published: December 2007

Oligonucleotide array comparative genomic hybridization (aCGH) was applied on fifteen gastric cancer (GCA) samples to reveal information of DNA copy number changes at an exon-level resolution. Twelve of the samples represented the intestinal (IGCA) and three the diffuse (DGCA) type of GCA. The samples had previously been assessed for genetic stability by microsatellite analysis and categorized into microsatellite phenotypes according to the type of alterations. As compared to our previous results obtained using cDNA platforms, the oligonucleotide platforms revealed more aberrations per sample (0–45 vs. 0–22). A total of 22 amplifications were detected by the oligonucleotide arrays. Ten of the amplicons had also been detected on the cDNA platform, but five of them spanned only one or a few cDNA clones, thus resembling apparent outliers. Two tumors showed five or more amplifications by oligonucleotide aCGH, suggesting the presence of an amplifier phenotype. The amplifications occurred irrespective of the microsatellite phenotypes. None of the DGCA tumors showed more than one aberration, whereas the IGCA tumors showed several aberrations. The increased resolution of the oligonucleotide arrays enabled the detection of amplicon boundaries at gene level, allowing, e.g., the determination of the 17q12 core amplicon and interstitial losses within the 8p23.1→p22 and 20q13.2→q13.1 amplifications. Previously no losses have been reported within amplified regions in GCA. In addition to novel amplified regions, the oligonucleotide array results describe novel targets for amplicons at 8p11 (SFRP1), 11p12 (LRRC4C), and 19q13.2 (CEACAM6).
Similarities in the chromosomal distribution of AG and AC repeats within and between Drosophila, human and barley chromosomes
Authors: Cuadrado A. , Jouve N.
Published: December 2007

Two simple sequence repeats (SSRs), AG and AC, were mapped directly in the metaphase chromosomes of man and barley (Hordeum vulgare L.), and in the metaphase and polytene chromosomes of Drosophila melanogaster. To this end, synthetic oligonucleotides corresponding to (AG)12 and (AC)8 were labelled by the random primer technique and used as probes in fluorescent in situ hybridisation (FISH) under high stringency and strict washing conditions. The distribution and intensity of the signals for the repeat sequences were found to be characteristic of the chromosomes and genomes of the three species analysed. The AC repeat sites were uniformly dispersed along the euchromatic segments of all three genomes; in fact, they were largely excluded from the heterochromatin. The Drosophila genome showed a high density of AC sequences on the X chromosome in both mitotic and polytene nuclei. In contrast, the AG repeats were associated with the euchromatic regions of the polytene chromosomes (and in high density on the X chromosome), but were only seen in specific heterochromatic regions in the mitotic chromosomes of all three species. In Drosophila, the AG repeats were exclusively distributed on the tips of the Y chromosome and near the centromere on both arms of chromosome 2. In barley and man, AG repeats were associated with the centromeres (of all chromosomes) and nucleolar organizer regions, respectively. The conserved chromosome distribution of AC within and between these three phylogenetically distant species, and the association of AG in specific chromosome regions with structural or functional properties, suggests that long clusters of these repeats may have some, as yet unknown, role.
A radiation hybrid map of river buffalo (Bubalus bubalis) chromosome 1 (BBU1)
Authors: Miziara M.N. , Goldammer T. , Stafuzza N.B. , Ianella P. , Agarwala R. , Schäffer A.A. , Elliott J.S. , Riggs P.K. , Womack J.E. , Amaral M.E.J.
Published: December 2007

The largest chromosome in the river buffalo karyotype, BBU1, is a submetacentric chromosome with reported homology between BBU1q and bovine chromosome 1 and between BBU1p and BTA27. We present the first radiation hybrid map of this chromosome containing 69 cattle derived markers including 48 coding genes, 17 microsatellites and four ESTs distributed in two linkage groups spanning a total length of 1330.1 cR5000. The RH map was constructed based on analysis of a recently developed river buffalo-hamster whole genome radiation hybrid (BBURH5000) panel. The retention frequency of individual markers across the panel ranged from 17.8 to 52.2%. With few exceptions, the order of markers within linkage groups is identical to the order established for corresponding cattle RH maps. The BBU1 map provides a starting point for comparison of gene order rearrangements between river buffalo chromosome 1 and its bovine homologs.
An integrated and comparative genetic map of the turkey genome
Authors: Reed K.M. , Chaves L.D. , Mendoza K.M.
Published: December 2007

An integrated genetic linkage map was developed for the turkey (Meleagris gallopavo) that combines the genetic markers from the three previous mapping efforts. The UMN integrated map includes 613 loci arranged into 41 linkage groups. An additional 105 markers are tentatively placed within linkage groups based on two-point LOD scores and 19 markers remain unlinked. A total of 210 previously unmapped markers has been added to the UMN turkey genetic map. Markers from each of the 20 linkage groups identified in the Roslin map and the 22 linkage groups of the Nte map are incorporated into the new integrated map. Overall map distance contained within the 41 linkage groups is 3,365 cM (sex-averaged) with the largest linkage group (94 loci) measuring 533.1 cM. Average marker interval for the map was 7.86 cM. Sequences of markers included in the new map were compared to the chicken genome sequence by ‘BLASTN’. Significant similarity scores were obtained for 95.6% of the turkey sequences encompassing an estimated 91% of the chicken genome. A physical map of the chicken genome based on positions of the turkey sequences was built and 36 of the 41 turkey linkage groups were aligned with the physical map, five linkage groups remain unassigned. Given the close similarities between the turkey and chicken genomes, the chicken genome sequence could serve as a scaffold for a genome sequencing effort in the turkey.
Migration of Neuroblasts from Neurogenic Placodes
Authors: Begbie Jo
Published: December 2007

Peripheral neurons involved in cephalic sensory systems are born in the ectoderm at a distance from the neural tube. The neuroblasts migrate internally, coalesce to form ganglia and extend axons to the central nervous system. This process has long been evident but little is known about the way it occurs. We have shown that coordination of the migration and integration with the hindbrain occurs through interaction with neural crest cells.