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Selected AbstractsParticle-in-Cell Simulation of Stationary Plasma ThrusterCONTRIBUTIONS TO PLASMA PHYSICS, Issue 8-9 2007F. Taccogna Abstract A very good example for the application of PIC techniques for detailed studies of low-temperature plasmas is the Hall thrusters. Here, a variety of models with different complexities are needed to get better insight into the physics of these systems. Particular emphasis has been spent for the geometrical scaling, for the simulation of the plasma-wall interaction inside the acceleration channel and for ion-neutral collision into the plume emitted from the thruster. Results show the axial acceleration mechanism, the secondary electron emission instability, the azimuthal fluctuations into the channel and the ion backflow and electron trapping in the plume. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Plasma Edge Physics with B2-EireneCONTRIBUTIONS TO PLASMA PHYSICS, Issue 1-2 2006R. Schneider Abstract The B2-Eirene code package was developed to give better insight into the physics in the scrape-off layer (SOL), which is defined as the region of open field-lines intersecting walls. The SOL is characterised by the competition of parallel and perpendicular transport defining by this a 2D system. The description of the plasma-wall interaction due to the existence of walls and atomic processes are necessary ingredients for an understanding of the scrape-off layer. This paper concentrates on understanding the basic physics by combining the results of the code with experiments and analytical models or estimates. This work will mainly focus on divertor tokamaks, but most of the arguments and principles can be easily adapted also to other concepts like island divertors in stellarators or limiter devices. The paper presents the basic equations for the plasma transport and the basic models for the neutral transport. This defines the basic ingredients for the SOLPS (Scrape-Off Layer Plasma Simulator) code package. A first level of understanding is approached for pure hydrogenic plasmas based both on simple models and simulations with B2-Eirene neglecting drifts and currents. The influence of neutral transport on the different operation regimes is here the main topic. This will finish with time-dependent phenomena for the pure plasma, so-called Edge Localised Modes (ELMs). Then, the influence of impurities on the SOL plasma is discussed. For the understanding of impurity physics in the SOL one needs a rather complex combination of different aspects. The impurity production process has to be understood, then the effects of impurities in terms of radiation losses have to be included and finally impurity transport is necessary. This will be introduced with rising complexity starting with simple estimates, analysing then the detailed parallel force balance and the flow pattern of impurities. Using this, impurity compression and radiation instabilities will be studied. This part ends, combining all the elements introduced before, with specific, detailed results from different machines. Then, the effect of drifts and currents is introduced and their consequences presented. Finally, some work on deriving scaling laws for the anomalous turbulent transport based on automatic edge transport code fitting procedures will be described. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Dichotic listening and school performance in dyslexiaDYSLEXIA, Issue 1 2008Turid Helland Abstract This study focused on the relationship between school performance and performance on a dichotic listening (DL) task in dyslexic children. Dyslexia is associated with impaired phonological processing, related to functions in the left temporal lobe. DL is a frequently used task to assess functions of the left temporal lobe. Due to the predominance of the contralateral neuronal pathways, a right ear advantage in the DL task reflects the superior processing capacity for the right ear stimulus in the left hemisphere (Kimura, 1963). Previous studies using DL in dyslexia are, however, inconclusive, and may reflect degree of severity of dyslexia. The aim of the present study was therefore to investigate lateralized processing in two sub-groups of dyslexia, differing in symptom severity. Two groups of dyslexic 12-year-old children and an age-matched control group were tested with a consonant,vowel DL task. The two dyslexia groups differed in severity through how they responded to training efforts being made in their schools, while otherwise being matched for age, IQ and diagnosis. The D1 (respondent group) group showed a DL performance pattern similar to the control group, i.e. a right ear advantage, while the D2 (non-respondent) group failed to show a right ear advantage on the DL task. The performance on the DL task by the two dyslexia groups may provide better insight as to the degree of reading and writing impairment in dyslexia. ,Cracking the code' and acquiring automatized literacy skills may seem harder for the D2 group children compared to the D1 children. Also, the present study points to the use of DL as a valid assessment tool in clinical work to improve differential diagnoses, particularly in relation to measures of school performance. Copyright © 2007 John Wiley & Sons, Ltd. [source] Cytokine therapy in dermatologyEXPERIMENTAL DERMATOLOGY, Issue 2 2002K. Asadullah Abstract: Cytokines have been in the focus of scientific interest for some years now. Analysing their expression permitted a better understanding of the pathogenesis of various diseases, including in dermatology. Moreover, they are now far beyond the stage when they were of interest only to the pathophysiological research sector: some cytokine therapies are already being employed as part of the clinical practice. In fact, several cytokines are used for the treatment of malignant, inflammatory and infectious skin diseases. Their stage of development ranges from advanced, already approved and well established therapies (e.g. IFN-, and IL-2 for melanoma) to early explorative trials (e.g. IL-4 and IL-10 for psoriasis). Some of the new approaches currently under investigation will actually lead to registration of new drugs for dermatological treatment and to supplement existing therapeutic options. Beside this, the results of clinical trials with cytokines are significantly contributing to our understanding of the pathophysiology of diseases. They will give a better insight into which mechanisms play a greater or lesser part in their development and may generate momentum for still better targeted pharmacological approaches. Here we would like to give an overview about the current stage of cytokine therapy and the prospects for dermatological indications. The terminology and immunobiology of cytokines are also briefly discussed, since for a sensible interpretation of the relevant findings a basic knowledge of these biologically highly active messenger substances is essential. [source] Vitiligo in an urban academic setting,INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 1 2010Taraneh Paravar MD Background, Vitiligo is a depigmenting disease of unknown etiology. A more complete understanding of vitiligo and associated conditions will provide better insight into the etiology and potential treatment options for this condition. We sought to gather information regarding associated conditions and other epidemiologic data on vitiligo. Methods, A retrospective chart review was performed of 135 patients with vitiligo seen between July 1, 2002 and June 30, 2005 at an academic medical center. Epidemiologic characteristics were recorded. Results, The patient population consisted of 80 women and 55 men with mean age of presentation of 36.8 years and average disease duration of 5.7 years. Vitiligo vulgaris was the predominant type of vitiligo and hypothyroidism was the most common co-morbidity. Anti-thyroid peroxidase and anti-thyroglobulin antibodies were found in 37% and 18% of patients, respectively. The highest proportion of thyroid abnormalities was found in age of onset category 21,30. Anti-nuclear antibodies were found in 33% of patients. Conclusion, The prevalence of anti-nuclear and anti-thyroid peroxidase antibodies was higher in our vitiligo study than that reported elsewhere. In addition, autoimmune thyroid disease may be more common in adult-onset vitiligo. [source] Tectonic and stratigraphic significance of the Middle Ordovician carbonate breccias in the Ogcheon Belt, South KoreaISLAND ARC, Issue 3 2002In-Chang Ryu Abstract Carbonate breccias occur sporadically in the Lower,Middle Ordovician Maggol Limestone exposed in the Taebacksan Basin in the northeastern part of the northeast,southwest-trending Ogcheon Belt, South Korea. These carbonate breccias have been previously interpreted as intraformational or fault-related breccias. Thus, little attention has been focused on tectonic and stratigraphic significance of these carbonate breccias. The present study, however, indicates that the majority of these carbonate breccias are solution,collapse breccias, which are causally linked to paleokarstification. Carbonate facies analysis in conjunction with conodont biostratigraphy suggests that an overall regression toward the top of the Maggol Limestone probably culminated in subaerial exposure of platform carbonates during the early Middle Ordovician (earliest Darriwilian). Extensive subaerial exposure of platform carbonates resulted in paleokarst-related solution,collapse breccias in the upper Maggol Limestone. This subaerial exposure event is manifested as a major paleokarst unconformity at the Sauk,Tippecanoe sequence boundary elsewhere beneath the Middle Ordovician succession and its equivalents, most notably North America and North China. Due to its global extent, this paleokarst unconformity has been viewed as a product of second- or third-order eustatic sealevel drop during the early Middle Ordovician. Although a paleokarst breccia zone is recognized beneath the Middle Ordovician succession in South Korea, the Sauk,Tippecanoe sequence boundary appears to be a conformable transgressive surface on the top of the paleokarst breccia zone in the upper Maggol Limestone. The paleokarst breccia zone beneath the conformable transgressive surface is represented by a thinning-upward stack of exposure-capped tidal flat-dominated cycles that are closely associated with multiple occurrences of paleokarst-related solution,collapse breccias. This paleokarst breccia zone was a likely consequence of repeated fourth- and fifth-order sealevel fluctuations. It suggests that second- and third-order eustatic sealevel drop may have been significantly tempered by substantial tectonic subsidence near the end of the Maggol deposition. The tectonic subsidence in the basin is also evidenced by the occurrence of coeval off-platform lowstand siliciclastic quartzite lenses as well as debris flow carbonate breccias (i.e. the Yemi Breccia). With the continued tectonic subsidence, subsequent rise in the eustatic cycle caused drowning and deep flooding of carbonate platform, forming a transgressive surface on the top of the paleokarst breccia zone. This tectonic implication contrasts notably with the slowly subsiding carbonate platform model for the basin as has been previously interpreted. Thus, it is proposed that the Taebacksan Basin in the northeastern part of the Ogcheon Belt evolved from a slowly subsiding carbonate platform to a rapidly subsiding intracontinental rift basin during the early Middle Ordovician. The proposed tectonic model in the basin gives much better insight to unravel the stratigraphic response to tectonic evolution of the Ogcheon Belt, which remains an enigmatic feature in formulating a tectonic framework of the Korean peninsula. The present study also provides a good example that the falling part of the eustatic sealevel cycle may not produce a significant event in a rapidly subsiding basin where the rate of eustatic fall always remained lower than the rate of subsidence. [source] Polymer characterization by ultrasonic wave propagationADVANCES IN POLYMER TECHNOLOGY, Issue 2 2008Francesca Lionetto Abstract The propagation of low-intensity ultrasound in polymers, acting as a high-frequency dynamic mechanical deformation, can be successfully used to monitor changes in the modulus of polymers associated with glass transition, crystallization, cross-linking, and other chemical and physical phenomena related to changes in the viscoelastic behavior, such as gelation phenomena. The velocity of sound is related to the polymer storage modulus and density, whereas the absorption of ultrasonic waves is related to the energy dissipation in the material and, therefore, to the loss modulus. Accordingly, ultrasonic measurements have been used by several authors to monitor the evolution of the viscoelastic moduli of polymers as a function of time or temperature and, recently, become a characterization technique of its own right, generally known as ultrasonic dynamic mechanical analysis (UDMA). Often the technique is used in conjunction with rheological methods as a means of providing a better insight into the viscoelastic behavior of polymer systems. As yet UDMA is underutilized primarily because of the low operating temperatures (usually below 100,C) of commercially available ultrasonic transducers, and also due to the requirement of a coupling medium to ensure an efficient energy transfer mechanism between the transducer and the test material. Despite these limitations, this paper shows that the use of ultrasonics is potentially a powerful method for the characterization of polymers, particularly as a tool for online monitoring of events occurring during polymer processing and in the manufacture of polymer matrix composites. The aim of this paper is to review the progress made in recent years, highlighting the potential and reliability of UDMA for monitoring physical transitions in polymers such as glass transition, melting, crystallization, as well as physical changes taking place during curing of thermosetting resins. © 2009 Wiley Periodicals, Inc. Adv Polym Techn 27:63,73, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20124 [source] Model population analysis for variable selectionJOURNAL OF CHEMOMETRICS, Issue 7-8 2010Hong-Dong Li Abstract To build a credible model for given chemical or biological or clinical data, it may be helpful to first get somewhat better insight into the data itself before modeling and then to present the statistically stable results derived from a large number of sub-models established only on one dataset with the aid of Monte Carlo Sampling (MCS). In the present work, a concept model population analysis (MPA) is developed. Briefly, MPA could be considered as a general framework for developing new methods by statistically analyzing some interesting parameters (regression coefficients, prediction errors, etc.) of a number of sub-models. New methods are expected to be developed by making full use of the interesting parameter in a novel manner. In this work, the elements of MPA are first considered and described. Then, the applications for variable selection and model assessment are emphasized with the help of MPA. Copyright © 2010 John Wiley & Sons, Ltd. [source] Preferential crystallization: Multi-objective optimization frameworkAICHE JOURNAL, Issue 2 2009Shrikant A. Bhat Abstract A four objective optimization framework for preferential crystallization of D-L threonine solution is presented. The objectives are maximization of average crystal size and productivity, and minimization of batch time and the coefficient of variation at the desired purity while respecting design and operating constraints. The cooling rate, enantiomeric excess of the preferred enantiomer, and the mass of seeds are used as the decision variables. The optimization problem is solved by using adaptation of the nondominated sorting genetic algorithm. The results obtained clearly distinguish different regimes of interest during preferential crystallization. The multi-objective analysis presented in this study is generic and gives a simplified picture in terms of three zones of operations obtained because of relative importance of nucleation and growth. Such analysis is of great importance in providing better insight for design and decision making, and improving the performance of the preferential crystallization that is considered as a promising future alternative to chromatographic separation of enantiomers. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Granulocyte elastase activity in static and flow gingival crevicular fluidJOURNAL OF PERIODONTAL RESEARCH, Issue 3 2003Lijian Jin Objectives:, This study aimed to evaluate the volume of gingival crevicular fluid (GCF) and granulocyte elastase activity in static GCF (sGCF) and flow GCF (fGCF) from subjects with various periodontal conditions. Methods:, Eleven periodontally healthy, 10 gingivitis and 12 periodontitis subjects were recruited and the sites investigated consisted of healthy sites from healthy subjects (HH); healthy (HG) and gingivitis sites (GG) from gingivitis subjects; and healthy (HP), gingivitis (GP) and periodontitis sites (PP) from periodontitis subjects. fGCF samples were collected either 1 min or 5 min following sGCF collection by paper strip technique. GCF volume was determined by Periotron® 6000 and granulocyte elastase activity was assayed with a specific substrate [l -pyroglutamyl- l -prolyl- l -valine- p -nitroanilide(pGluProVal-pNA)]. Results:, At baseline, no significant differences existed in clinical and GCF parameters between the two matched sites for subsequent collection of fGCF samples either 1 min or 5 min after sGCF sampling in all subjects. The flow exudate in HG and HP sites quickly replenished to sGCF levels, while a delayed replenishment was found in HH sites, despite the similar sGCF volumes of these sites. The GCF volume and elastase levels in the fGCF at 1 min were higher in GP sites than in GG sites (P < 0.05). Overall, depletion of elastase levels in the fGCF at 1 min was observed in all subjects, whereas elastase levels in the fGCF at 5 min had replenished to sGCF levels in HP, GP, PP sites and GG sites, but had remained at a lower level in HH and HG sites. An overall positive correlation was found between sGCF and fGCF for GCF volume and elastase activity (P < 0.001); however, this correlation varied with GCF parameters and with site conditions of the subjects concerned. Conclusions:, This study shows that patterns of dynamic changes in GCF flow and elastase activity varied under different periodontal conditions. Assessment of both sGCF and fGCF may allow better insight into the dynamic change of the target components in GCF. [source] Species-specific interaction of HIV protease inhibitors with accumulation of cholyl-glycylamido-fluorescein (CGamF) in sandwich-cultured hepatocytesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2010Zhi-wei Ye Abstract Using sandwich-cultured hepatocytes from rat, dog, pig, and human, we investigated the species-specificity of interaction of HIV protease inhibitors (PI) with in vitro hepatic accumulation of the bile salt analogue cholyl-glycylamido-fluorescein (CGamF). Extracellular sodium depletion or coincubation with the OATP/Oatp inhibitors rifampicin and digoxin revealed that about 35% of active CGamF accumulation was mediated by Ntcp/NTCP in rat and human hepatocytes, while the contribution of this sodium-dependent transporter reached 50,60% in dog and pig hepatocytes. One or more sodium-independent transporters, likely belonging to the Oatp/OATP family, constitute a major transport mechanism for CGamF accumulation. Various HIV PI (0.5, 5, 25,µM) exhibited pronounced species differences in their interaction with active CGamF accumulation (1,µM), although some similarity was observed between the dog and human interaction profiles when HIV PI were tested at 0.5,µM. Atazanavir, indinavir, and darunavir were the most potent inhibitors of CGamF accumulation in human hepatocytes. Potent inhibition of CGamF accumulation by ritonavir in rat hepatocytes contrasted with a weak effect in human hepatocytes. Thorough characterization of in vitro disposition of probe substrates in preclinical species compared to human hepatocytes will ultimately support a better insight in species-specific mechanisms underlying drug interactions and drug-mediated toxicity. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 2886,2898, 2010 [source] Changes in oxyhemoglobin dissociation curve in intrabdominal organs during pig experimental orthotopic liver transplantationLIVER TRANSPLANTATION, Issue 7 2005Georgia Kostopanagiotou Liver transplantation has become a gold standard treatment for irreversible liver disease. Conventional measures of oxygenation are inadequate to understand the dynamics of regional oxygen metabolism during liver transplantation because they represent global markers of tissue dysoxia. Therefore, the addition of an assessment of the hemoglobin O2 binding capacity can give a better insight into systemic and regional tissue oxygenation and can reflect a more accurate estimation of oxygen release to the tissues than can the hemoglobin, the PaO2 and SaO2 alone. This prospective study was designed to evaluate possible alterations in the oxyhemoglobin dissociation curve of vital end organs (small bowel, liver, and kidney) in an experimental liver transplantation model. Fifteen pigs with body weights ranging from 25 to 30 kg were used for the study. Five healthy pigs underwent a sham operation under general anesthesia (group A-control). Ten pigs underwent orthotopic liver transplantation (OLT). Five of them were healthy (group B), whereas the other five were in acute liver failure, which had been surgically induced (group C). Systemic arterial blood pressure, cardiac index, and pulmonary and systemic vascular resistance indexes were measured. Venous blood gas analysis was also performed from pulmonary artery, superior mesenteric, hepatic, and renal veins at well-defined timepoints during the course of the OLT. A statistically significant (P < 0.05) decrease of P50 in groups B and C compared with group A was observed 30 minutes after reperfusion in the systemic circulation, hepatic, and renal veins. This coincided with a decrease in animal temperature 30 minutes after reperfusion. Regarding group C, after reperfusion of the newly transplanted liver there was a significant increase of P50 in the small bowel in comparison to baseline values. In conclusion, these changes in P50 may suggest the occurrence of abnormal tissue oxygenation after reperfusion. (Liver Transpl 2005;11:760,766.) [source] TRIP: a psycho-educational programme in Hong Kong for people with schizophreniaOCCUPATIONAL THERAPY INTERNATIONAL, Issue 2 2007Sunny Ho-Wan Chan Abstract ,TRIP' (Transforming Relapse and Instilling Prosperity) is a ward-based illness management programme that aims to decrease treatment non-compliance and relapse rate by improving the insight and health of acute psychiatric patients with schizophrenia. Eighty-one stable male acute psychiatric patients with schizophrenia were randomized to receive the TRIP programme (n = 44) or the comparison group of traditional ward occupational therapy (WOT) programme (n = 37). Participants' insights and health were assessed by the Unawareness of Mental Disorder Scale and the Hong Kong version of the Short Form-36 (SF-36) health survey, respectively. Each group was then followed up for a 12-month period. One-way analysis of covariance (ANCOVA) showed that participants in the TRIP programme had significantly better insight and health than a comparison group during post-study measurement. Participants in the TRIP programme had significantly fewer re-admissions in the 12-month follow-up period than those who attended the WOT programme. In summary the TRIP programme, as led by an occupational therapist, was effective in improving insight, awareness of health and in having a lower re-admission rate than a traditional occupational therapy programme. Copyright © 2007 John Wiley & Sons, Ltd. [source] Genomic scale analysis of the human keratinocyte response to broad-band ultraviolet-B irradiationPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 1 2002Joe Takao Ultraviolet B (UVB) radiation is an important inducer of many biologic changes in skin, of which keratinocytes are a key target. To gain better insight into changes in gene expression generated in the early phase after UVB exposure, we used complementary RNA (cRNA) microarray hybridization to compare differences in mRNA expression of UVB-irradiated (single dose of 100 J/m2 broad-band UVB) and sham-irradiated primary cultured human keratinocytes. Six hours after irradiation, total RNA was isolated from keratinocytes, and cRNA was synthesized and hybridized to a GeneChip expression array (Affymetrix) consisting of 6800 genes. Based on a threshold of >,twofold change, 187 genes (2.8%) were designated to be the most UVB-responsive. Surprisingly, none of these genes had been shown previously to be modulated by UVB. Conversely, several genes in the microarray that had been reported previously to be UVB- responsive by other methods showed less (< twofold) or no change. Northern blotting of seven differentially modulated genes produced results similar to those derived from microarray technology, thereby validating the accuracy of screening. Clustering based on known or likely functions indicated that among 88 upregulated genes, nine encode for cytochrome c subunits, six for ribosomal proteins, and two for regulators of apoptosis. By contrast, many of the 99 downregulated genes are involved in transcription, differentiation and transport. These findings indicate that keratinocytes respond to a single low dose of broad-band UVB irradiation by enhancing processes involved in energy production and translation, while suppressing those related to transcription, differentiation and transport. [source] A comparative study of transformation of micellar structures in CTAB and TTAB binary systems using Positron Lifetime SpectroscopyPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2009R. Yadav Abstract The micellar structures of cetyl-tri-methyl ammonium bromide (CTAB) and its homologues have been investigated employing several conventional techniques. However, due to lack of sensitivity inherent in these techniques and the perturbation introduced by the probe, the detailed structures of the aggregates in the so-called single phase regions of these systems are far from being fully understood. Positron has been found to be a useful non-destructive probe for investigating micellar structures in surfactant systems [1-3] The present study is an effort to get a better insight into the micellar structures and their transformations in CTAB and TTAB aqueous binary systems Positron lifetime spectroscopy has been employed to study these systems covering a wide range of surfactant concentrations. A comparative study of the results obtained for the two surfactant systems have been discussed in this paper. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The use of the Pareto shape parameter as a leading indicator of process safety performancePROCESS SAFETY PROGRESS, Issue 3 2009Fred Henselwood Abstract Metrics addressing process safety incident performance typically focus on frequency and severity statistics. Often, these lagging metrics are not overly sensitive to actual performance, making trending and forecasting difficult. This article presents the results from a statistical study of a large incident dataset where changes in the Pareto shape parameter were observed as a function of time. This approach has been found to give far better insight into process safety performance than traditional incident metrics and readily relates back to concepts such as the "incident triangle" and "layers of protection." Through the application of this approach, trends within process safety incident performance have been observed earlier, and more accurate forecasting has allowed for the identification of anomalies. In turn, these critical observations have allowed for the better structuring and targeting of process safety programs. Although incident data are generally considered as a lagging indicator, this approach has clearly reduced the lag time associated with this type of data and has given valuable insight into the current status of process safety performance. © 2009 American Institute of Chemical Engineers Process Saf Prog 2009 [source] Proteomic analysis of core breakdown disorder in Conference pears (Pyrus communis L.)PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 12 2007Romina Pedreschi Abstract 2-DE was applied to study core breakdown disorder in controlled atmosphere stored 'Conference' pears. This physiological disorder is characterized by internal browning of the fruit tissue and the development of cavities. Suitable protein phenol extraction/ammonium acetate-methanol precipitation and 2-DE protocols for a wide pH range were established for pear tissue. The protein expression profiles of healthy, sound (intact tissue of pears with core breakdown) and brown tissue were analyzed with the univariate non-parametric Kolmogorov-Smirnov test and multivariate statistical techniques such as principal component analysis and partial least square discriminant analysis. Both statistical approaches revealed interesting differentially expressed proteins between healthy and disordered pears. LC-ESI-MS/MS identification of differentially expressed proteins between healthy and sound tissue revealed their participation in the energy metabolism, the antioxidant system and ethylene biosynthesis. Up-regulated characteristic proteins in brown tissue were mainly involved in energy metabolism and defense mechanisms. Proteomics coupled to univariate and multivariate statistical techniques seems to be an efficient approach to get a better insight into the different mechanisms and pathways leading to the core breakdown disorder. [source] z -Transform and adaptive signal processing in analysis of tracer dataTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 3 2002Leszek Furman Abstract In the field of data processing, the common practice is to interpret tracer-determined residence time distributions (RTDs) of particles through different arrangements of elementary flow models. However, such analysis needs an a priori chosen arrangement of these models, and some information carried by the RTD curve may be lost. This paper presents a competitive method based on adaptive filtering in a z -transform domain, and it may give better insight into flow patterns in a steady-state flow system. A physical interpretation of the transfer function was developed. The application of this modelling to the interpretation of radiotracer data from recent studies in different industry sectors is presented. Dans le domaine du traitement des données, la pratique courante consiste à interpréter les distributions de temps de séjour (DTS) déterminées par traceur de particules à travers différents arrangements de modèles d'écoulements élémentaires. Toutefois, une telle analyse implique de choisir a priori l'arrangement de ces modèles. Ainsi, certaines informations données par la courbe de DTS peuvent se perdre. On présente dans cet article une méthode compétitive basée sur le filtrage adaptatif dans le domaine de la transformée en z, qui peut permettre une meilleure compréhension des schémas d'écoulement pour un système en écoulement permanent. Une interprétation physique de la fonction de transfert a été développée. On présente l'application de cette modélisation de l'interprétation des données de traceurs radioactifs provenant d'études récentes dans différents secteurs industriels. [source] Evaluating the multiple coil configurations of the EM38DD and DUALEM-21S sensors to detect archaeological anomaliesARCHAEOLOGICAL PROSPECTION, Issue 2 2009David Simpson Abstract The multiple coil configurations of two electromagnetic induction sensors were tested on a field with strong electrical and magnetic contrasts. The first sensor, EM38DD, measures either the apparent electrical conductivity (ECa or ,a) or the apparent magnetic susceptibility (MSa or ,a) of the soil at two coil orientations. The second sensor, DUALEM-21S, measures both ECa and MSa at two coil orientations and two coil separations. The goal was to test if measuring with the multiple coils resulted in a better detection of near-surface artefacts and the natural soil variability. The ECa of all coil configurations was closely related to the depth of a clay substrate beneath the topsoil sandy loam, which was verified by soil augering. Configurations with a shallower theoretical depth of exploration were less influenced by the clay substrate. Combining two coil configurations revealed important ECa anomalies, not visible on individual measurements, associated with a brick wall foundation and a former ditch. The MSa maps showed totally different anomaly patterns, related to anthropogenic disturbances in the soil, such as the filling-in with brick rubble of a former pond. Depending on the depth and thickness of the disturbance and the relative response of the sensor configurations, the MSa anomalies were entirely positive for one configuration but other configurations also had negative anomalies. It was concluded that multiple coil configurations provide a better insight into the build-up of the soil profile and are better able to detect anomalies than single measurements. Copyright © 2009 John Wiley & Sons, Ltd. [source] Structure of rat odorant-binding protein OBP1 at 1.6,Å resolutionACTA CRYSTALLOGRAPHICA SECTION D, Issue 5 2009Scott A. White The nasal mucosa is a specialist interfacial region sandwiched between the olfactory system and the gaseous chemical milieu. In mammals and insects, this region is rich in odorant-binding proteins that are thought to aid olfaction by assisting mass transfer of the many different organoleptic compounds that make up the olfactory landscape. However, in mammals at least, our grasp on the exact function of odorant-binding proteins is tentative and better insight into the role of these proteins is warranted, not least because of their apparent significance in the olfactory systems of insects. Here, the crystal structure of rat odorant-binding protein 1 is reported at 1.6,Å resolution. This protein is one of the best-characterized mammalian odorant-binding proteins and only the third such protein structure to be solved at high resolution. The protein was crystallized in the holo form and contains an unidentifiable ligand that is probably an artefact from the Pichia pastoris expression system. Comparisons are made between this structure and a modelled OBP1 structure produced using the crystal structure of aphrodisin as a template. Comparisons are also made between OBP1 and the other two rat OBP subtypes, for which crystallographic data are unavailable. Interestingly, we also show that OBP1 is monomeric, which is in contrast to its previous assignment. [source] A proteomic approach for identifying cellular proteins interacting with erythropoietin in recombinant Chinese hamster ovary cellsBIOTECHNOLOGY PROGRESS, Issue 1 2010Jee Yon Kim Abstract Identification of the cellular proteins interacting with incompletely folded and unfolded forms of erythropoietin (EPO) in recombinant CHO (rCHO) cells leads to better insight into the possible genetic manipulation approaches for increasing EPO production. To do so, a pull-down assay was performed with dual-tagged (N-terminal GST- and C-terminal hexahistidine-tagged) EPO expressed in E. coli as bait proteins and cell lysates of rCHO cells (DG44) as prey proteins. Cellular proteins interacting with dual-tagged EPO were then resolved by two-dimensional gel electrophoresis (2DE) and identified by MALDI-TOF MS/MS. A total of 27 protein spots including glucose-regulated protein 78 (GRP78) were successfully identified. Western blot analysis of GRP78 confirmed the results of the MS analyses. Taken together, a pull-down assay followed by a proteomic approach is found to be an efficient means to identify cellular proteins interacting with foreign protein in rCHO cells. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Expression, purification, crystallization and preliminary X-ray diffraction analysis of ,-11 giardin from Giardia lambliaACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2006Puja Pathuri ,-11 Giardin, a protein from the annexin superfamily, is a 35.0,kDa protein from the intestinal protozoan parasite Giardia lamblia which triggers a form of diarrhea called giardiasis. Here, the cloning, expression, purification and the crystallization of ,-11 giardin under two different conditions and in two different space groups is reported. Crystals from the first condition diffracted to 1.1,Å and belong to a primitive orthorhombic space group, while crystals from the second condition, which included calcium in the crystallization solution, diffracted to 2.93,Å and belong to a primitive monoclinic space group. Determination of the detailed atomic structure of ,-11 giardin will provide a better insight into its biological function and might establish whether this class of proteins is a potential drug target against giardiasis. [source] Neuroticism, alexithymia, negative affect and positive affect as predictors of medically unexplained symptoms in primary care1ACTA NEUROPSYCHIATRICA, Issue 4 2002V. De Gucht Background:, Somatization has been defined in a number of ways. Despite their differences, these definitions have one element in common, namely the presence of somatic symptoms that cannot be explained (adequately) by organic findings. Objective: The primary objectives of the dissertation were to gain a better insight into the concept of somatization, and to study (prospectively) the relationship between neuroticism and alexithymia, two personality traits that have been shown to be related to somatization, the affective state dimensions positive and negative affect (or psychological distress) and medically unexplained symptoms. Method: A selective review was conducted regarding conceptual and methodological issues related to somatization. A total number of 318 patients, presenting to their primary care physician with medically unexplained symptoms, participated in the prospective study. Both at baseline and at 6-month follow-up a number of measures were filled out with respect to somatization, neuroticism, alexithymia, negative and positive affect, anxiety and depression. Results: The concept of somatization was clarified, thereby making use of the distinction between presenting and functional somatization. The personality traits neuroticism and alexithymia were found to have an indirect influence on symptom reports. Both the cross-sectional and follow-up data pointed to the importance of positive and negative affect as determinants of (changes in) number of symptoms (over time). Negative affect, together with the alexithymia dimension measuring difficulty identifying feelings, predicted symptom persistence. Conclusions: The theoretical as well as therapeutic implications of the present paper may give an impetus to new research in the domain of somatization. [source] Genetic and phenotypic analysis of B-cell post-transplant lymphoproliferative disorders provides insights into disease biologyHEMATOLOGICAL ONCOLOGY, Issue 4 2008Efsevia Vakiani Abstract B-cell post-transplant lymphoproliferative disorders (PTLD) are classified as early lesions, polymorphic lymphomas (P-PTLD) and monomorphic lymphomas (M-PTLD). These morphologic categories are thought to reflect a biologic continuum, although supporting genetic data are lacking. To gain better insights into PTLD pathogenesis, we characterized the phenotypes, immunoglobulin (Ig) gene alterations and non-Ig gene (BCL6, RhoH/TTF, c-MYC, PAX5, CIITA, BCL7A, PIM1) mutations of 21 PTLD, including an IM-like lesion, 8 P-PTLD and 12 M-PTLD. Gene expression profile analysis was also performed in 12 cases. All PTLD with clonal Ig rearrangements showed evidence of germinal centre (GC) transit based on the analysis of Ig and BCL6 gene mutations, and 74% had a non-GC phenotype (BCL6,±,MUM1+). Although surface Ig abnormalities were seen in 6/19 (32%) PTLD, only three showed ,crippling' Ig mutations indicating other etiologies for loss of the B-cell receptor. Aberrant somatic hypermutation (ASHM) was almost exclusively observed in M-PTLD (8/12 vs. 1/8 P-PTLD) and all three recurrent cases analysed showed additional mutations in genes targeted by ASHM. Gene expression analysis showed distinct clustering of PTLD compared to B-cell non-Hodgkin lymphomas (B-NHL) without segregation of P-PTLD from non-GC M-PTLD or EBV+ from EBV, PTLD. The gene expression pattern of PTLD appeared more related to that of memory and activated B-cells. Together, our results suggest that PTLD represent a distinct type of B-NHL deriving from an antigen experienced B-cell, whose evolution is associated with accrual of genetic lesions. Copyright © 2008 John Wiley & Sons, Ltd. [source] One size does not fit all: Managing IT employees' employment arrangementsHUMAN RESOURCE MANAGEMENT, Issue 3 2007Jayesh Prasad As alternative employment arrangements proliferate within the information technology (IT) function, it becomes increasingly important to understand the impact of these arrangements on IT employees. A prevalent notion in the IT literature is that these employees are homogeneous in their work values and that they prefer similar employment arrangements. Given the inefficiency of designing individual employment programs, we advocate a middle ground between the two extremes of individualized employment arrangements and "one size fits all." We conducted two studies. The first study developed an individual's work values profile as a psychological construct. It used a national sample of IT employees to validate a simple, heuristic procedure that was successful in classifying about 80% of the sample into three work values profiles. The second study demonstrated the use of work values profiles for understanding how employment arrangements differentially influence employee satisfaction. It applied the validated procedure to a single organization in order to demonstrate the general applicability of the procedure and to show that it provides researchers and HR professionals with better insights than the assumption that all IT employees are alike. © 2007 Wiley Periodicals, Inc. [source] Fluctuating asymmetry and developmental instability in evolutionary biology: past, present and futureJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2006S. V. DONGEN Abstract The role of developmental instability (DI), as measured by fluctuating asymmetry (FA), in evolutionary biology has been the focus of a wealth of research for more than half a century. In spite of this long period and many published papers, our current state of knowledge reviewed here only allows us to conclude that patterns are heterogeneous and that very little is known about the underlying causes of this heterogeneity. In addition, the statistical properties of FA as a measure of DI are only poorly grasped because of a general lack of understanding of the underlying mechanisms that drive DI. If we want to avoid that this area of research becomes abandoned, more efforts should be made to understand the observed heterogeneity, and attempts should be made to develop a unifying statistical protocol. More specifically, and perhaps most importantly, it is argued here that more attention should be paid to the usefulness of FA as a measure of DI since many factors might blur this relationship. Furthermore, the genetic architecture, associations with fitness and the importance of compensatory growth should be investigated under a variety of stress situations. In addition, more focus should be directed to the underlying mechanisms of DI as well as how these processes map to the observable phenotype. These insights could yield more efficient statistical models and a unified approach to the analysis of patterns in FA and DI. The study of both DI and canalization is indispensable to obtain better insights in their possible common origin, especially because both have been suggested to play a role in both micro- and macro-evolutionary processes. [source] Secretory Cavity Development and Its Relationship with the Accumulation of Essential Oil in Fruits of Citrus medica L. var. sarcodactylis (Noot.) SwingleJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 5 2006She-Jian Liang Abstract The developmental types of secretory cavities in Citrus remain controversial. The relationship between secretory cavity development and the accumulation of essential oil in fruits of Citrus species is also unknown. In order to develop better insights into these problems, histological, histochemical, and cytochemical methods were used to investigate secretory cavity development and the accumulation of essential oil at different developmental stages of fruits of Citrus medica L. var. sarcodactylis (Noot.) Swingle. The results indicate that the secretory cavity of the variety seemed to originate from an epidermal cell and a subepidermal cell. These two cells underwent successive divisions, resulting in the formation of two parts: (i) a conical cap; and (ii) a globular gland. The formation of the lumen was schizolysigenous. Regular changes in the size of vacuoles and the accumulation of essential oil were revealed during the process of secretory cavity development. In addition, when fruits were a light yellow or golden color, the structure of secretory cavities was well developed and the content of essential oil in a single fruit reached a maximum. It would be most appropriate to collect the fruit as a medicinal material at this time. (Managing editor: Wei Wang) [source] Proteomic strategies in multiple sclerosis and its animal modelsPROTEOMICS - CLINICAL APPLICATIONS, Issue 11 2007Stella Elkabes Dr. Abstract The early and precise diagnosis, the prognosis, and the clinical management of multiple sclerosis, remain a considerable challenge. In recent years, the development of novel and powerful proteomic techniques prompted the use of these approaches for the search of unique biomarkers in the cerebrospinal fluid of multiple sclerosis patients. A few studies have also utilized proteomics to delineate the profile of differentially expressed proteins in animal models of the human disease in order to gain global insights into affected pathways. The identification of differentially expressed proteins may be an initial step in the discovery of novel targets and mechanisms that play critical roles in the pathology of multiple sclerosis. Based on these findings, future investigations may elucidate the events leading to demyelination, axonal damage, and neurodegeneration, providing better insights into mechanisms governing the onset and progression of the disease. Although these proteomic studies provide valuable information, they are also faced with a number of challenges. The present review discusses some of the strengths and limitations of proteomic investigations as applied to multiple sclerosis. [source] 2163: Identification of novel disease gene for primary congenital glaucoma (PCG) through homozygosity mapping and next-generation sequencing strategies in a large consanguineous pedigreeACTA OPHTHALMOLOGICA, Issue 2010H VERDIN Purpose Primary congenital glaucoma (PCG) is caused by developmental anomalies of the trabecular meshwork and the anterior chamber angle resulting in an increased ocular pressure (IOP) and optic nerve damage. In general PCG displays an autosomal recessive inheritance pattern and is genetically heterogeneous. To date, three PCG loci are known, namely GLC3A, GLC3B and GLC3C, and two causal genes have been identified, CYP1B1 located in the GLC3A locus and LTPB2 located at 1.3 MB proximal to the GLC3C locus. The purpose of the current study is to identify the causal disease gene in a large consanguineous family with PCG, originating from Jordany. CYP1B1 mutations and linkage to the LTBP2, GLCB3 and GLCC3 locus were previously excluded. Methods In a first step, DNA from members from the consanguineous family will be genotyped by 250K GeneChip Mapping Affymetrix arrays. Homozygosity mapping will be applied to identify potential disease loci, using a homemade Perl script. Next, microsatellite analysis will be performed in order to confirm findings and to narrow down candidate regions. Subsequently, candidate regions of interest will be captured (Agilent) and sequenced on the Illumina Genome Analyser IIx (GAIIx). Gene and variant prioritization will be done using in-house developed software, followed by segregation analysis and screening in control individuals. At last, a cohort of 30 molecularly unsolved PCG patients will be screened for mutations in the newly identified disease. Conclusion The identification of a new disease gene for PCG may lead to better insights into the molecular pathogenesis of glaucoma, and might uncover novel therapeutic strategies. [source] Prevalence of various radiographic manifestations of osteochondrosis and their correlations between and within joints in Dutch Warmblood horsesEQUINE VETERINARY JOURNAL, Issue 1 2009E. M. Van Grevenhof Summary Reasons for performing study: Osteochondrosis (OC) is the most important orthopaedic developmental disorder in horses and may manifest in several different forms. No detailed study on the prevalence and/or interrelation of these forms is available, even though these data are a prerequisite for conclusive genetic studies. Objectives: To assess the prevalence of the various manifestations of OC as detected radiographically and to evaluate possible relationships between their occurrence within the same joint and between different joints. Methods: The FP (femoropatellar), TC (tarsocrural) and MCP/MTP (metacarpophalangeal/metatarsophalangeal) joints of 811 yearlings selected randomly, descending from 32 representative stallions, were radiographed and scored for the presence and grade of osteochondrotic lesions. Results were compared at the sire, animal, joint and predilection site levels. Results: In the FP joint, the percentage of animals showing normal joint contours in all sites was 60.7%. For the TC joint and the combined MCP/MTP joints, these figures were 68.6 and 64.6%, respectively. For all joints combined, the percentage dropped to 30.5%. Sedation improved detection of OC lesions in the FP joint. There was a high correlation between the right and left joints. The correlation between flattened bone contours and fragments was considerably less. Conclusions: Scoring on a detailed scale is necessary to achieve good insight into the prevalence of OC. Observations on the right and left joints can be combined in further analyses, whereas flattened bone contours and fragments should be evaluated as statistically different disorders. Potential relevance: This study provides insight into the prevalences of various manifestations of OC and their relationships, within and between joints. These results form the basis for detailed quantitative and/or molecular genetic studies that should lead to the establishment of breeding indices and/or genetic marker sets for OC. [source] |