bluuebunny/crossref_metadata_2025 huggingface dataset:
Baffinia hesslei (Annenkova), n. comb. (Polychaeta: Terebellidae) from eastern Canada
Authors: Fournier Judith A. , Barrie John
Published: January 2009

The species Baffinia multisetosa Wesenberg-Lund, 1950 is synonymized with Terebella hesslei Annenkova, 1924. The genus Baffinia is retained, resulting in the new combination Baffinia hesslei. The taxonomic position of this species within the Terebellidae is discussed, and two new records from eastern Canada are reported.
Ecology and evolution of sympatric sticklebacks (Gasterosteus): morphological and genetic evidence for a species pair in Enos Lake, British Columbia
Authors: McPhail J. D.
Published: January 2009

Two morphological forms of three-spined stickleback (Gasterosteus) coexist in Enos Lake near Nanoose Bay, Vancouver Island. For convenience, the two forms are referred to as "benthics" and "limnetics." Morphological and biochemical characteristics of the two forms were examined and artificial hybrids (F1 and F2) reared in the laboratory. The two forms differ in male nuptial colour, body shape, and gill raker architecture. These differences are inherited and have remained stable for several generations. Benthics and limnetics also differ in allele frequencies at three loci (Mdh-3, Ck, and Pgm). At one of these loci (Mdh-3) the limnetic form is polymorphic and the benthic form is fixed. Since the two forms maintain themselves as discrete entities and there is no evidence of gene flow, they are considered separate biological species. It is not certain that either of these species is Gasterosteus aculeatus. Similar species pairs exist in other lakes in the Strait of Georgia region but, at present, their relationship to the species pair in Enos Lake is unknown.
EVOLVING EDITED k-NEAREST NEIGHBOR CLASSIFIERS
Authors: GIL-PITA ROBERTO , YAO XIN
Published: January 2009

The k-nearest neighbor method is a classifier based on the evaluation of the distances to each pattern in the training set. The edited version of this method consists of the application of this classifier with a subset of the complete training set in which some of the training patterns are excluded, in order to reduce the classification error rate. In recent works, genetic algorithms have been successfully applied to determine which patterns must be included in the edited subset. In this paper we propose a novel implementation of a genetic algorithm for designing edited k-nearest neighbor classifiers. It includes the definition of a novel mean square error based fitness function, a novel clustered crossover technique, and the proposal of a fast smart mutation scheme. In order to evaluate the performance of the proposed method, results using the breast cancer database, the diabetes database and the letter recognition database from the UCI machine learning benchmark repository have been included. Both error rate and computational cost have been considered in the analysis. Obtained results show the improvement achieved by the proposed editing method.
REVERSE ENGINEERING A SOCIAL AGENT-BASED HIDDEN MARKOV MODEL — ViSAGE
Authors: CHEN HUNG-CHING (JUSTIN) , GOLDBERG MARK , MAGDON-ISMAIL MALIK , WALLACE WILLIAM A.
Published: January 2009

We present a machine learning approach to discover the agent dynamics that drives the evolution of the social groups in a community. We set up the problem by introducing an agent-based hidden Markov model for the agent dynamics: an agent's actions are determined by micro-laws. Nonetheless, We learn the agent dynamics from the observed communications without knowing state transitions. Our approach is to identify the appropriate micro-laws corresponding to an identification of the appropriate parameters in the model. The model identification problem is then formulated as a mixed optimization problem. To solve the problem, we develop a multistage learning process for determining the group structure, the group evolution, and the micro-laws of a community based on the observed set of communications among actors, without knowing the semantic contents. Finally, to test the quality of our approximations and the feasibility of the approach, we present the results of extensive experiments on synthetic data as well as the results on real communities, such as Enron email and Movie newsgroups. Insight into agent dynamics helps us understand the driving forces behind social evolution.
A NEW METHOD FOR FACIAL FEATURES QUANTIFICATION OF CARICATURE BASED ON SELF-REFERENCE MODEL
Authors: NI FEI , FU ZHUANG , CAO QIXIN , ZHAO YANZHENG
Published: January 2009

Some facial features that differ from an ordinary face should be identified by a computer when generating a facial caricature. These distinctive facial features are called self-features. Compared with traditional Mean Face Model (MFM) that is unable to quantify these self-features well, a Self-Reference Model (SRM) is presented in this paper. Firstly, based on the physiology structure of a front face, a self-reference is found, and this reference is used to measure the self-features. According to the self-reference, some standard facial parameters are worked out by collecting statistic data of many facial images. Then, in an input face image, by evaluating some differences between the input face and the standard facial parameters, the self-features are properly estimated and quantified. Finally, by analyzing some caricatures produced by caricaturists, the SRM can prove the validity of the proposed Algorithm.
COMBINING GENERALIZED NMF AND DISCRIMINATIVE MIXTURE MODELS FOR CLASSIFICATION OF GENE EXPRESSION DATA
Authors: LIU WEIXIANG , YUAN KEHONG , WU JIAN , YE DATIAN , JI ZHEN , CHEN SIPING
Published: January 2009

Classification of gene expression samples is a core task in microarray data analysis. How to reduce thousands of genes and to select a suitable classifier are two key issues for gene expression data classification. This paper introduces a framework on combining both feature extraction and classifier simultaneously. Considering the non-negativity, high dimensionality and small sample size, we apply a discriminative mixture model which is designed for non-negative gene express data classification via non-negative matrix factorization (NMF) for dimension reduction. In order to enhance the sparseness of training data for fast learning of the mixture model, a generalized NMF is also adopted. Experimental results on several real gene expression datasets show that the classification accuracy, stability and decision quality can be significantly improved by using the generalized method, and the proposed method can give better performance than some previous reported results on the same datasets.
ACCUMULATIVE INTERSECTION SPACE BASED CORNER DETECTION ALGORITHM
Authors: LU NA , FENG ZUREN
Published: January 2009

There is no parametric formulation of corner, so the conventional Hough transform cannot be employed to detect corners directly. A random corner detection method is developed in this paper based on a new concept "accumulative intersection space" under Monte Carlo scheme. This method transforms the corner detection in the image space into local maxima localization in the accumulative intersection space where the intersections are accumulated by random computations. The proposed algorithm has been demonstrated by both theory and experiments. The proposed algorithm is isotropic, robust to image rotation, insensitive to noise and false corners on diagonal edges. Unlike the other existing contour based corner detection methods, our algorithm can effectively avoid the influence of the edge detectors, such as rounding corners or line interceptions. Extensive comparisons among our approach and the other detectors including Harris operator, Fei Shen and Han Wang detector, Han Wang and Brady detector, Foveated Visual Search method and SIFT feature, have shown the effectiveness of our method.
HIGH SENSITIVITY AND HIGH DYNAMIC RANGE OPTICAL MICRO-RADIATOR VACUUM SENSOR FABRICTED WITH CMOS TECHNOLOGY
Authors: MA Y. , LAWSON R. P. W. , ROBINSON A. M.
Published: January 2009

A Complementary Metal Oxide Silicon (CMOS) optical micro-radiator vacuum sensor has been designed, tested and calibrated. The package is comprised of a micromachined radiator and a photodetector. The sensitivity improvement of the system over the conventional Pirani gauge is up to nine magnitudes depending on the operating power of the micro-radiator. To increase sensor's dynamic range, an automated power-switching system has been demonstrated for pressure sensing operated with constant photodetector output. Calibration of the system has been performed by comparison with secondary standards. Experimental results showed that the sensor's measurement range from 10-3 Pa to 105 Pa has been achieved as its relative error is less than 8%.
TIME-TO-CONTACT INFORMATION ESTIMATION FOR MONOCULAR MOBILE ROBOTS
Authors: LIU RONG , MENG MAX Q. H.
Published: January 2009

Time-to-contact (TTC) provides vital information for obstacle avoidance and for the visual navigation of a robot. In this paper, we present a novel method to estimate the TTC information of a moving object for monocular mobile robots. In specific, the contour of the moving object is extracted first using an active contour model; then the height of the motion contour and its temporal derivative are evaluated to generate the desired TTC estimates. Compared with conventional techniques employing the first-order derivatives of optical flow, the proposed estimator is less prone to errors of optical flow. Experiments using real-world images are conducted and the results demonstrate that the developed method can successfully achieve TTC with an average relative error (ARVE) of 0.039 with a single calibrated camera.
INTELLIGENT VISION SYSTEMS FOR ROBOTIC APPLICATIONS
Authors: MAEDER ANDREAS , BISTRY HANNES , ZHANG JIANWEI
Published: January 2009

Vision-based sensors are a key component for robot-systems, where many tasks depend on image data. Realtime control constraints bind a lot of processing power for only a single sensor modality. Dedicated and distributed processing resources are the "natural" solution to overcome this limitation. This paper presents experiments, using embedded processors as well as dedicated hardware, to execute various image (pre)processing tasks. Architectural concepts and requirements for intelligent vision systems have been acquired.
HAND MANIPULATION TRAINING IN HAPTIC VIRTUAL ENVIRONMENTS
Authors: YANG XIAOLI , KIM YOUN K.
Published: January 2009

Continuing advances in virtual reality (VR) technology with respect to the new addition of force and touch feedbacks have enhanced VR realism and led to the development of many useful and accessible VR systems. One of the emerging research fields is in rehabilitation training. This paper introduces a virtual reality-based hand manipulation training system with three applications: virtual writing, virtual painting and virtual dialing. The system is mainly for training hand movement precision, speed, force, and direction control. A haptic device — PHANTOM Premium 1.0 is used to give the user immediate force feedbacks to feel immersed in the virtual environment during the training session. A new collision detection method is developed for accurate and rapid calculation of the interaction between the haptic and virtual environments. The implementation performances are calculated and given to the user in real time. The practicing results are also saved for evaluation and supervision by the specialist.
GEOMETRY OF PROTEINS: SEARCH FOR INTERNAL SURFACES
Authors: SADOC JEAN-FRANÇOIS
Published: January 2009

Voronoi tessellations and their dual Delaunay tetrahedral tessellations provide versatile representations of three-dimensional structures of proteins, allowing a strict definition of neighborhoods of the different amino acids, considered as rigid entities. They give geometrical and topological information coded in the adjacency matrix (often called contact map in biology). Using this approach, this paper presents a two-dimensional description of internal surfaces, which are tools used to understand the conformation of globular proteins. These surfaces are triangulated surfaces tiled by faces of Delaunay tetrahedra. Two simple types of surfaces are presented, characterized by their topology: disk-like or torus-like. The torus-like surface is relevant in the description of secondary structures. The disk-like surface characterizes the collapse of the chain onto itself.
PROTEIN ULTRAMETRICITY AND SPECTRAL DIFFUSION IN DEEPLY FROZEN PROTEINS
Authors: AVETISOV VLADIK , BIKULOV ALBERT
Published: January 2009

Surprisingly accurate description of spectral diffusion in deeply frozen proteins is constructed on the basis of protein ultrametricity. We show that the ultrametric diffusion equation with self-similar hierarchy of the transition rates offers a simple description of protein dynamics in the spectral diffusion context. Earlier the same ultrametric diffusion equation has been used in the description of ligand-rebinding kinetics of myoglobin. Thus ultrametricity offers a universal background for the description of protein dynamics on very different scales of protein motions.
Potential Health Impact of Nanoparticles
Authors: Xia Tian , Li Ning , Nel Andre E.
Published: January 2009

Although mankind stands to obtain great benefit from nanotechnology, it is important to consider the potential health impacts of nanomaterials (NMs). This consideration has launched the field of nanotoxicology, which is charged with assessing toxicological potential as well as promoting safe design and use of NMs. Although no human ailments have been ascribed to NMs thus far, early experimental studies indicate that NMs could initiate adverse biological responses that can lead to toxicological outcomes. One of the principal mechanisms is the generation of reactive oxygen species and oxidant injury. Because oxidant injury is also a major mechanism by which ambient ultrafine particles can induce adverse health effects, it is useful to consider the lessons learned from studying ambient particles. This review discusses the toxicological potential of NMs by comparing the possible injury mechanisms and adverse health effects of engineered and ambient ultrafine particles.
Prioritizing Clinical Preventive Services: A Review and Framework with Implications for Community Preventive Services
Authors: Maciosek Michael V. , Coffield Ashley B. , Edwards Nichol M. , Flottemesch Thomas J. , Solberg Leif I.
Published: January 2009

Setting priorities on the basis of factors such as health impact and economic value is the key first step to ensure that the most important services receive the most attention. Few prioritization efforts have been published that produce either rankings or information that can guide decision making. We propose a framework to help decision makers and clinicians balance short-term demands against long-term objectives. This framework provides guidance for decisions about scope, prioritization criteria, evidence review methods, evaluation of criteria fit, and presentation of results. The framework is the result of our experience setting priorities among clinical preventive services. It has not been tested in prioritizing community interventions and other health care services but should provide a useful starting point for designing priority-setting efforts in those areas.
Inhibition of adipocyte differentiation by insulin-like growth factor-binding protein-3
Authors: Chan Sophie S. Y. , Schedlich Lynette J. , Twigg Stephen M. , Baxter Robert C.
Published: January 2009

Insulin-like growth factor-binding protein-3 (IGFBP-3) interacts with the type II nuclear receptors retinoid X receptor (RXR)α and retinoic acid receptor-α and modulates their transcriptional activity. Peroxisome proliferator-activated receptor (PPAR)γ, a related nuclear receptor that dimerizes with RXRα, plays an important role in adipocyte differentiation. IGFBP-3 is regulated during adipocyte differentiation, but its role in this process is unknown. We demonstrate that IGFBP-3 interferes with the PPARγ-dependent processes of adipocyte differentiation and maintenance of the gene expression characteristic of mature adipocytes. Treatment of adipocytes with exogenous IGFBP-3, but not an IGFBP-3 mutant that does not bind RXRα or PPARγ, decreased markers of adipocyte differentiation, PPARγ, and resistin but increased the preadipocyte marker plasminogen activator inhibitor-1. Furthermore, expression of human IGFBP-3, but not the IGFBP-3 mutant, by preadipocytes inhibited preadipocyte differentiation as determined by gene markers and lipid accumulation. IGFBP-3 interacted with PPARγ in vitro and in 3T3-L1 adipocyte lysates and inhibited PPARγ heterodimerization with RXRα in vitro. Wild-type IGFBP-3, but not mutant IGFBP-3, blocked ligand-induced transactivation of PPAR response element in 3T3-L1 cells. The observation that IGFBP-3 inhibits adipocyte differentiation and impacts on the PPARγ system suggests a role for IGFBP-3 in the pathogenesis of obesity and insulin resistance.
Acyl-coenzyme A:cholesterol acyltransferases
Authors: Chang Ta-Yuan , Li Bo-Liang , Chang Catherine C. Y. , Urano Yasuomi
Published: January 2009

The enzymes acyl-coenzyme A (CoA):cholesterol acyltransferases (ACATs) are membrane-bound proteins that utilize long-chain fatty acyl-CoA and cholesterol as substrates to form cholesteryl esters. In mammals, two isoenzymes, ACAT1 and ACAT2, encoded by two different genes, exist. ACATs play important roles in cellular cholesterol homeostasis in various tissues. This chapter summarizes the current knowledge on ACAT-related research in two areas: 1) ACAT genes and proteins and 2) ACAT enzymes as drug targets for atherosclerosis and for Alzheimer's disease.
Aging augments mitochondrial susceptibility to heat stress
Authors: Haak Jodie L. , Buettner Garry R. , Spitz Douglas R. , Kregel Kevin C.
Published: January 2009

The pathophysiology of aging is accompanied by a decline in tolerance to environmental stress. While mitochondria are primary suspects in the etiology of aging, little is known about their ability to tolerate perturbations to homeostasis in older organisms. To investigate the role of mitochondria in the increased susceptibility to heat stress that accompanies aging, young and old Fischer 344 rats underwent a heat stress protocol known to elicit exaggerated cellular damage with aging. At either 2 or 24 h after heat stress, livers were removed from animals, and hepatic mitochondria were isolated. Electron microscopy revealed extensive morphological damage to mitochondria from young and, to a greater extent, old rats after heat stress. There was also a significant loss of cytochrome c from old, but not young, mitochondria and a persistent increase in 4-hydroxynonenal-modified proteins in old vs. young mitochondria exposed to heat stress. Electron paramagnetic resonance measurements of superoxide indicate greater superoxide production from mitochondria of old compared with young animals and suggest that mitochondrial integrity was altered during heat stress. The mitochondrial stress response, which functions to correct stress-induced damage to mitochondrial proteins, was also blunted in old rats. Delayed and reduced levels of heat shock protein 60 (Hsp60), the main inducible mitochondrial stress protein, were observed in old compared with young mitochondria after heat stress. Additionally, the amount of Hsp10 protein increased in young, but not old, rat liver mitochondria after hyperthermic challenge. Taken together, these data suggest that mitochondria in old animals are more vulnerable to incurring and less able to repair oxidative damage that occurs in response to a physiologically relevant heat stress.
Pruritic and Nociceptive Sensations and Dysesthesias From a Spicule of Cowhage
Authors: LaMotte R. H. , Shimada S. G. , Green B. G. , Zelterman D.
Published: January 2009

Although the trichomes (spicules) of a pod of cowhage ( Mucuna pruriens) are known to evoke a histamine-independent itch that is mediated by a cysteine protease, little is known of the itch and accompanying nociceptive sensations evoked by a single spicule and the enhanced itch and pain that can occur in the surrounding skin. The tip of a single spicule applied to the forearm of 45 subjects typically evoked 1) itch accompanied by nociceptive sensations (NS) of pricking/stinging and, to a lesser extent, burning, and 2) one or more areas of cutaneous dysesthesia characterized by hyperknesis (enhanced itch to pricking) with or without alloknesis (itch to stroking) and/or hyperalgesia (enhanced pricking pain). Itch could occur in the absence of NS or one or more dysesthesias but very rarely the reverse. The peak magnitude of sensation was positively correlated for itch and NS and increased (exhibited spatial summation) as the number of spicules was increased within a spatial extent of 6 cm but not 1 cm. The areas of dysesthesia did not exhibit spatial summation. We conclude that itch evoked by a punctate chemical stimulus can co-exist with NS and cutaneous dysesthesias as may occur in clinical pruritus. However, cowhage itch was not always accompanied by NS or dysesthesia nor was a momentary change in itch necessarily accompanied by a similar change in NS or vice versa. Thus there may be separate neural coding mechanisms for itch, nociceptive sensations, and each type of dysesthesia.
Targeted transgenesis at the HPRT locus: an efficient strategy to achieve tightly controlled in vivo conditional expression with the tet system
Authors: Palais G. , Nguyen Dinh Cat A. , Friedman H. , Panek-Huet N. , Millet A. , Tronche F. , Gellen B. , Mercadier J.-J. , Peterson A. , Jaisser F.
Published: January 2009

The tet-inducible system has been widely used to achieve conditional gene expression in genetically modified mice. To alleviate the frequent difficulties associated with recovery of relevant transgenic founders, we tested whether a controlled strategy of transgenesis would support reliable cell-specific, doxycycline (Dox)-controlled transgene expression in vivo. Taking advantage of the potent hypoxanthine-aminopterin-thymidine selection strategy and an embryonic stem (ES) cell line supporting efficient germ-line transmission, we used hypoxanthine phosphoribosyltransferase ( HPRT) targeting to insert a single copy tet-inducible construct designed to allow both glucocorticoid receptor (GR) and β-galactosidase (β-Gal) expression. Conditional, Dox-dependent GR and β-Gal expression was evidenced in targeted ES cells. Breeding ES-derived single copy transgenic mice with mice bearing appropriate tet transactivators resulted in β-Gal expression both qualitatively and quantitatively similar to that observed in mice with random integration of the same construct. Interestingly, GR expression in mice was dependent on transgene orientation in the HPRT locus while embryonic stem cell expression was not. Thus, a conditional construct inserted in single copy and in predetermined orientation at the HPRT locus demonstrated a Dox-dependent gene expression phenotype in adult mice suggesting that controlled insertion of tet-inducible constructs at the HPRT locus can provide an efficient alternative strategy to reproducibly generate animal models with tetracycline-induced transgene expression.
Estimation of Compositions of Zr-Cu Binary Sputtered Film and Its Characterization
Authors: Kondoh Katsuyoshi , Fujita Junji , Umeda Junko , Serikawa Tadashi
Published: January 2009

Zr-Cu amorphous films were prepared by radio-frequency (RF) magnetron sputtering on glass substrate using two kinds of the elemental composite targets: Cu chips on Zr plate and Zr chips on Cu plate. It was easy to precisely control chemical compositions of sputtered films by selecting the chip metal and the number of chips. It is possible to accurately estimate the film compositions by using the sputtered area and the deposition rate of Cu and Zr. XRD analysis on every as-sputtered film showed the broadened pattern. Zr-rich composition film, however, revealed a small peak at the diffraction angle of , and Cu-rich one indicated it at . TEM and electron diffraction analysis on the former also showed the main Zr ring patterns and its streaks. Zr-rich composition film with Cu content of 34 at% or less indicated a good corrosion resistance by salt spray test. On the other hand, Cu-rich version with 74 at% Cu or more was poor in corrosion resistance. This was because Zr was reactively passive, and caused the spontaneous formation of a hard non-reactive surface film that inhibited further corrosion than Cu.
Multiparametric Monitoring of Tumor Response to Chemotherapy by Noninvasive Imaging
Authors: Medarova Zdravka , Rashkovetsky Leonid , Pantazopoulos Pamela , Moore Anna
Published: January 2009

With the emerging concept of individualized cancer therapy, it becomes crucial to develop methods for the noninvasive assessment of treatment outcome. With this in mind, we designed a novel approach for the comprehensive evaluation of response to chemotherapy with the established agent doxorubicin in a preclinical breast cancer model. This approach delivers information not only about change in tumor size but also about target antigen expression. Our strategy relies on a tumor-specific contrast agent (MN-EPPT) targeting the underglycosylated MUC-1 (uMUC-1) tumor antigen, found on more than 90% of breast cancers and predictive of chemotherapeutic response. MN-EPPT consists of superparamagnetic iron oxide nanoparticles (MN) for magnetic resonance imaging, modified with Cy5.5 dye (for near-IR fluorescence optical imaging), and conjugated to peptides (EPPT), specifically recognizing uMUC-1. In vivo, treatment of mice bearing orthotopic human breast carcinomas with doxorubicin led to a reduction in tumor mass and resulted in down-regulation of uMUC-1. The tumor-specific accumulation of MN-EPPT allowed the assessment of change in tumor volume by noninvasive imaging. Furthermore, in mice injected with MN-EPPT, tumor delta-T2 was significantly reduced after treatment with doxorubicin, indicating a lower accumulation of MN-EPPT and reflecting the reduced expression of uMUC-1. With these studies, we have shown the utility of magnetic resonance imaging for the multiparametric characterization of breast tumor response to chemotherapy. This approach has the potential of significantly advancing our ability to better direct the development of molecularly targeted individualized therapy protocols because it permits the monitoring of therapy on a molecular scale. [Cancer Res 2009;69(3):1182–9]
Determinantes de las respuestas a vacunas orales en países en vías de desarrollo
Authors: Sack David A. , Qadri Firdausi , Svennerholm Ann-Mari
Published: January 2009

Las vacunas orales que se han diseñado para uso global no inducen necesariamente las mismas respuestas inmunitarias en todos los niños de todo el mundo. De hecho, varias vacunas inducen a menudo respuestas medias de anticuerpos menos frecuentes y menores en niños en países en vías de desarrollo, lo que permite suponer que las vacunas pueden producir un efecto menos protector en los niños de estas zonas. Aunque los motivos de esta respuesta menos enérgica no se conocen por completo, parece que factores relacionados con la nutrición, incluyendo la desnutrición de proteínas y calorías y la desnutrición de micronutrientes, son aspectos importantes para comprender la hiporreactividad observada en estos niños. También parecen importantes cuestiones relacionadas, entre las que destacan la lactancia materna, la interferencia a partir de anticuerpos placentarios maternos, infecciones parasitarias intestinales, lesión de la mucosa intestinal y, posiblemente, malnutrición materna durante el embarazo. Las vacunas diseñadas para administración oral tendrán que ser ajustadas a estos problemas potenciales con objeto de incrementar al máximo sus beneficios para todos los niños. Las vacunas orales que se administran en niños de países en vías de desarrollo pueden requerir dosis mayores de vacunas, dosis de refuerzo, complementos de calorías, micronutrientes y vitaminas, retirada de la leche materna antes de la administración de las vacunas, medicamentos antihelmínticos u otras medidas para desarrollar sus beneficios totales.
Selección de los principales problemas de seguridad de las vacunas
Authors: Iskander John K. , Gidudu Jane , Arboleda Nelson , Huang Wan-Ting
Published: January 2009

Ejemplos recientes de los principales beneficios en salud pública de la vacunación incluyen reducciones globales de la mortalidad por sarampión y el registro de niveles bajos de enfermedades evitables por vacunas en Estados Unidos. No obstante, los problemas reales o percibidos de seguridad de las vacunas pueden ejercer un impacto adverso sobre los programas de vacunación. La monitorización sólida de la seguridad, posterior a la aprobación, que combina la vigilancia activa y la vigilancia pasiva con el uso de definiciones de casos estandarizados para los efectos adversos es la base científica para evaluar los problemas de seguridad. Entre los aspectos incipientes de la ciencia de seguridad de las vacunas destacan las redes de investigación clínica y la investigación de la comunicación del riesgo de las vacunas. Entre los problemas actuales de seguridad y de gran intensidad destacan la introducción de dos vacunas antirotavirus de segunda generación, las cuales requieren una estrecha monitorización de la invaginación intestinal. Hasta la fecha, los datos de EE.UU. no indican ningún riesgo elevado asociado a la vacuna de Merck aprobada (Rotateq®). Una cuestión de interés global es el empleo de timerosal como agente conservante en viales de vacunas multidosis. Las revisiones independientes exhaustivas, así como la investigación publicada recientemente, han reafirmado la ausencia de asociación entre timerosal y trastornos del desarrollo neurológico, incluyendo el autismo. El uso dilatado de la vacuna antigripal anual y la planificación pandémica en el mundo desarrollado, o en vías de desarrollo, deben incluir planes para la monitorización de la seguridad. A medida que aumenta el número de vacunas recién aprobadas se están identificando cada vez más errores potencialmente evitables en la administración de vacunas e incidentes posteriores a la vacunación, como el sincope. Los médicos de atención primaria y otros que participan en la administración de vacunas deben seguir procedimientos correctos de almacenamiento, manejo y administración de las vacunas y deben participar en los sistemas de notificación de efectos adversos tras la inmunización (EATI). La Brighton Collaboration proporciona otra salida, en la cual pueden participar los médicos e investigadores interesados incrementando la base de conocimientos globales sobre seguridad de las vacunas. El aumento del conocimientos de los sistemas de seguridad de las vacunas y la participación en los mismos, a todos los niveles, de los sistemas de atención sanitaria en ámbitos tanto de países desarrollados como países en vías de desarrollo permitirá a las vacunas mantener su excelente registro de trayectoria de seguridad, dado que los datos de seguridad se utilizan para mejorar los procedimientos de inmunización.
The Bone Morphogenetic Protein Antagonist Gremlin Promotes Vascular Smooth Muscle Cell Apoptosis
Authors: Maciel Thiago Trovati , Melo Rosilene Santos , Campos Alexandre Holthausen
Published: January 2009

Background: Previous studies from our laboratory demonstrated that gremlin significantly increases vascular smooth muscle cell (VSMC) proliferation and migration. The present study investigates gremlin expression in the initial stages of rat carotid balloon injury and its effects on VSMC apoptosis. Methods: Gremlin mRNA expression was evaluated in rat carotids and cultured VSMCs by quantitative PCR. Apoptosis was analyzed in A7r5 cells and rabbit primary VSMCs following gremlin gene overexpression or silencing by chromatin morphology and caspase-3 activity. Results: Vascular injury promoted a significant decrease in gremlin mRNA levels. In addition, platelet-derived growth factor, angiotensin II and transforming growth factor (TGF)-β1 promoted coordinated regulation of gremlin and bone morphogenetic protein (BMP)-4 expression in opposite directions according to the confluence status of VSMC culture. In A7r5 cells, gremlin overexpression was able to increase apoptosis, as demonstrated by chromatin morphology and caspase-3 activity, while BMP administration promoted opposite effects. Finally, in agreement with our results, gremlin gene silencing effectively suppressed apoptosis in A7r5 cells and rabbit VSMCs. Conclusion: Gremlin is regulated by growth factors and vascular injury and is involved in modulation of VSMC apoptosis. Modifications of gremlin expression during vascular injury may contribute to the apoptosis resistance of VSMCs.
The Role of Angiogenic Growth Factors in Arteriogenesis
Authors: Schierling Wilma , Troidl Kerstin , Troidl Christian , Schmitz-Rixen Thomas , Schaper Wolfgang , Eitenmüller Inka K.
Published: January 2009

Background/Aims: Collateral vessels restore only about 40% of the maximum dilatory reserve after femoral artery occlusion, whereas complete normalization is reached by increased fluid shear stress (FSS). We studied the role of known potent angiogenic growth factors (separately or in combination) in arteriogenesis by determining their expression in FSS-stimulated collaterals and close-to-collateral infusion of growth factor peptides in a rabbit model of femoral artery occlusion. Methods: Values of maximum collateral conductance (Cmax) and post mortem angiograms were compared to those achievable by high FSS. mRNA levels of growth factor ligands and receptors were determined in FSS-stimulated collaterals. Results: Seven days after vessel occlusion, FSS-stimulated legs showed a Cmax not significantly different from that of not occluded femoral arteries. Arteriogenesis was significantly less enhanced after growth factor treatment (MCP-1 86%, Ad5.1-FGF-4 75%, bFGF 72%, PDGF 64%, VEGF 50% of Cmax after FSS stimulation). RT-PCR showed no differential expression of FGF receptors, but an up-regulation of VEGF-receptor-2. Conclusion: The most potent known angiogenic growth factors at high pharmacological doses reach only a fraction of the maximum conductance obtained by high FSS. Arteriogenesis differs from angiogenesis, so the main focus to markedly improve arteriogenesis should be put on the underlying mechanisms of shear stress.
Impact of Incremental Risk Factors on Peritoneal Dialysis Patient Survival: Proposal of a Simplified Clinical Mortality Risk Score
Authors: Chung Sung Hee , Noh Hyunjin , Jeon Jin Seok , Han Dong Cheol , Lindholm Bengt , Lee Hi Bahl
Published: January 2009

Background/Aim: Peritoneal dialysis (PD) patient survival is influenced by many factors and there is no consensus on the relative importance of these predictors, independently or combined. This study was designed to evaluate how these independent factors, alone or in various combinations, may influence PD patient survival. Methods: A peritoneal equilibration test, subjective global assessment (SGA), and comorbid diseases (CMD) were assessed. Results: On multivariate analysis, age (>60 years), CMD, malnutrition, and low RRF (≤2 ml/min) were independent predictors of mortality. Three-year patient survival was 100, 95, 75, 49, and 0%, and the risk ratio for mortality was 1.0, 6.6, 21.9, and 85.9 in patients with none, one, two, three, and four of these risk factors, respectively. Conclusions: The combination of independent predictors of mortality in PD patients leads to a markedly increasing risk for mortality. Evaluation of a single risk factor underestimates the true impact of risk factors.
Effect of FX Dialysers on Systemic Inflammation and Quality of Life in Chronic Haemodialysis Patients
Authors: Boudville Neil , Horner Marilyn , McEwan Elizabeth , Lim Wai H. , Mudge David W. , Markus Hadley E.
Published: January 2009

Background: The FX class of haemodialysers features a new class of high-flux polysulfone membrane which has been suggested to induce less inflammation. Methods: This was a randomized, cross-over study performed on 33 haemodialysis patients. Patients were randomized to FX60 or HF80 dialysers for 3 months and then changed to the other dialyser. Interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), and C-reactive protein (CRP) were measured at baseline, and every 3 months. The Kidney Disease Quality of Life Short Form was also administered. Results: The mean of the difference in the IL-6 level between dialysers was 1.4 ± 8.0 pg/ml (95% CI –1.8, 4.5 pg/ml). There was no significant difference in TNF-α (95% CI –0.35, 0.18 pg/ml) or CRP levels (95% CI –2.67, 6.20 mg/l). The quality of social interaction and role limitations caused by physical health problems were significantly higher with the FX60, p = 0.04 and 0.047, respectively. Conclusions: The FX dialysers do not result in a significant difference in the level of systemic inflammation compared to the HF80.
Acceptance and Commitment Therapy: A Meta-Analytic Review
Authors: Powers Mark B. , Zum Vörde Sive Vörding Maarten B. , Emmelkamp Paul M.G.
Published: January 2009

Background: There are now a substantial number of controlled trials investigating the efficacy of acceptance and commitment therapy (ACT). This meta-analysis combined multiple well-controlled studies to help clarify the overall impact of ACT relative to waiting lists, psychological placebos, treatment as usual, and established therapies. Method: A comprehensive literature search produced 18 randomized controlled trials (n = 917) that were included in the final analyses. Effect size was computed with Hedges’s g which can be interpreted with Cohen’s convention of small (0.2), medium (0.5), and large (0.8) effects. Results: There was a clear overall advantage of ACT compared to control conditions (effect size = 0.42). The average ACT-treated participant was more improved than 66% of the participants in the control conditions. Analyzed separately ACT was superior to waiting lists and psychological placebos (effect size = 0.68) and treatment as usual (effect size = 0.42). However, ACT was not significantly more effective than established treatments (effect size = 0.18, p = 0.13). Also, ACT was not superior to control conditions for the distress problems (anxiety/depression: effect size = 0.03, p = 0.84). Conclusions: The results reveal that ACT is more effective than control conditions for several problem domains, but there is no evidence yet that ACT is more effective than established treatments.
Long-Term EGF Treatment Partially Prevents Reduction of Renal Blood Flow in Response to Neonatally Induced Partial Unilateral Ureteral Obstruction
Authors: Wen Jian Guo , Wang Gui Xian , Chen Yue , Ringgaard Steffen , Vinter-Jensen Lars , Jørgensen Troels Munch , Li Zhenzhen , Stødkilde-Jørgensen Hans , Nielsen Søren , Djurhuus Jens Christian , Frøkiær Jørgen
Published: January 2009

Background/Aims: To investigate the effects of long-term epidermal growth factor (EGF) treatment on kidney growth, renal blood flow (RBF), AQP2 expression and urine output in newborn rats with partial unilateral ureteral obstruction (PUUO). Methods: PUUO (n = 29) and sham-operated control (CON) (n = 26) was created in 2-day-old rats. Fifteen PUUO and 14 CON rats were treated with EGF beginning from the second day after operation to 8 weeks of age. Total kidney volume (TKV) and RBF were measured by MRI at weeks 4 and 8, respectively. Urine volume and osmolality, plasma osmolality, and free water clearance were measured. Renal AQP2 expression was determined using semiquantitative immunoblotting. Results: PUUO induced a severe hydronephrosis and RBF reduction in the obstructed kidney which was attenuated in EGF-treated rats. Body weight, urine output and free water clearance increased, osmolality and the osmolar clearance decreased significantly in EGF-treated rats, despite unchanged AQP2 levels. Conclusions: Long-term EGF treatment attenuated the obstruction- induced RBF reduction. Body weight, urine output increased, and urine osmolality decreased in both control and PUUO rats treated with EGF. Solute-free water clearance increased in PUUO rats which seem to be independent of AQP2 expression.
Identification of Gene Transcripts in Rat Frontal Cortex That Are Regulated by Repeated Electroconvulsive Seizure Treatment
Authors: Huang Chih-Ting , Chen Chia-Hsiang
Published: January 2009

Background/Aims: Electroconvulsive therapy (ECT) is an effective treatment modality for severe psychiatric disorders. Many studies have suggested that the therapeutic efficacy of ECT can be attributed to the structural and functional readjustment of the brain cells, which is mediated by differential gene expression in the brain. The aim of this study is to understand the molecular mechanism of ECT. Methods: We used microarray-based gene expression profiling technology and real-time quantitative PCR (RT-qPCR) to screen differentially expressed genes in the brain in a rat model of ECT. Results: Four upregulated and three downregulated genes were identified in this study. The 4 upregulated genes are S100 protein, beta polypeptide (S100b), S100 calcium binding protein A13_predicted (S100a13_predicted), diazepam-binding inhibitor (Dbi), and YKT6 homolog (S. Cerevisiae) (Ykt6), respectively; while the 3 downregulated genes are basigin (Bsg), histidine triad nucleotide binding protein 1(Hint 1), and neural precursor cell expressed, developmentally downregulated gene 8 (Nedd8), respectively. Conclusion: In view of the neurobiological function of these genes and their relevance to mental disorders, repeated ECS can affect gene expression involved in the neurotransmission and synaptic plasticity, which may account for the clinical effects of ECT.
Past Rifampicin Dosing Determines Rifabutin Resistance of Helicobacter pylori
Authors: Suzuki Shoji , Suzuki Hidekazu , Nishizawa Toshihiro , Kaneko Fumihiko , Ootani Sumire , Muraoka Hiroe , Saito Yoshimasa , Kobayashi Intetsu , Hibi Toshifumi
Published: January 2009

Background: Recently, the number of Helicobacter pylori isolates showing antibiotic resistance has been increasing. Rifabutin (RFB) is one of the possible candidates for H. pylori eradication. In the present study, the RFB minimum inhibitory concentrations (MICs) and the resistance-determining genes to RFB (rpoB) were examined to clarify the relationship between drug MICs, rpoB mutations, and past history of rifampicin (RFP) treatment. Methods: The MICs of RFB and rpoB mutations were examined for 48 strains with failure of H. pylori eradication in the University Hospital and 46 isolated from patients at a specialized hospital for chronic respiratory diseases without past H. pylori eradication. Past RFP treatment was also examined. Results: Eight of 94 strains showed high RFB MICs and 6 of the 8 strains showed rpoB point mutations. Although no strains showed high RFB MICs among 48 strains from the patients in the University Hospital, all 7 strains isolated from patients with past RFP treatment showed high RFB MICs (≥0.12 mg/l). Conclusion: Although RFB might be a potential candidate component of a new H. pylori eradication regimen following the first- or second-line failure, it should be used after examining a past history of RFP treatment.
The Influence of Learning on Evolution: A Mathematical Framework
Authors: Paenke Ingo , Kawecki Tadeusz J. , Sendhoff Bernhard
Published: January 2009

The Baldwin effect can be observed if phenotypic learning influences the evolutionary fitness of individuals, which can in turn accelerate or decelerate evolutionary change. Evidence for both learning-induced acceleration and deceleration can be found in the literature. Although the results for both outcomes were supported by specific mathematical or simulation models, no general predictions have been achieved so far. Here we propose a general framework to predict whether evolution benefits from learning or not. It is formulated in terms of the gain function, which quantifies the proportional change of fitness due to learning depending on the genotype value. With an inductive proof we show that a positive gain-function derivative implies that learning accelerates evolution, and a negative one implies deceleration under the condition that the population is distributed on a monotonic part of the fitness landscape. We show that the gain-function framework explains the results of several specific simulation models. We also use the gain-function framework to shed some light on the results of a recent biological experiment with fruit flies.
Review of fuzzy system models with an emphasis on fuzzy functions
Authors: Türkşen I. Burhan
Published: January 2009

Fuzzy system modelling (FSM) is one of the most prominent tools that can be used to identify the behaviour of highly non-linear systems with uncertainty. In the past, FSM techniques utilized Type 1 fuzzy sets in order to capture the uncertainty in the system. However, since Type 1 fuzzy sets express the belongingness of a crisp value x' of an input variable x in a fuzzy set A by a crisp membership value μA(x'), they cannot fully capture the uncertainties associated with higher-order imprecisions in identifying membership functions. In the future, we are likely to observe higher types of fuzzy sets, such as Type 2 fuzzy sets. The use of Type 2 fuzzy sets and linguistic logical connectives has drawn a considerable amount of attention in the realm of FSM in the last two decades. In this paper, we first review Type 1 fuzzy system models known as Zadeh, Takagi— Sugeno and Turkşen models; then we review potentially future realizations of Type 2 fuzzy systems again under the headings of Zadeh, Takagi—Sugeno and Turkşen fuzzy system models, in contrast to Type 1 fuzzy system models. Zadeh's and Takagi—Sugeno's models are essentially fuzzy rule base (FRB) models, whereas Turkşen's models are essentially fuzzy function (FF) models. Type 2 fuzzy system models have a higher predictive power. One of the essential problems of Type 2 fuzzy system models is computational complexity. In data-driven FSM methods discussed here, a fuzzy C-means (FCM) clustering algorithm is used in order to identify the system structure, ie, either the number of fuzzy rules or alternately the number of FFs.
A Professional Development School—Sponsored Summer Program for At-Risk Secondary Students
Authors: Cuddapah Jennifer L. , Masci Frank J. , Smallwood Jo Ellen , Holland Jennifer
Published: January 2009

The development and implementation of a Professional Development School (PDS)— sponsored summer program for at-risk secondary students is described. Literature related to PDSs and summer programs is followed by a presentation of data findings and analysis. Attendance and grade point average data gathered on the 17 participating rising ninth graders indicate that the described summer program had a positive student impact. Benefits for the university and school constituents as well as implications for future practice and research are described.
Adolescent Friendship Relations and Developmental Outcomes
Authors: Wissink Inge B. , Deković Maja , Meijer Anne Marie
Published: January 2009

The first aim of the present study was to examine associations between different aspects of adolescent friendship relations (i.e., frequency of contact with friends, trust in friends, and perceived friends' deviance) on one hand, and adolescent problem behavior and self-esteem on the other hand. The second aim was to determine whether the findings hold for adolescents from three different ethnic groups and for boys and girls. A sample of 508 Dutch, Turkish, and Moroccan adolescents living in the Netherlands filled in a battery of questionnaires at school. Having contact with deviant friends was the strongest contributor to both aggressive and delinquent problem behavior. Trust in friends was the strongest contributor to self-esteem. In general, gender differences were more pronounced than differences among the ethnic groups.