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Selected AbstractsORIGINAL RESEARCH,EPIDEMIOLOGY: Effect of Sexual Function on Health-Related Quality of Life Mediated by Depressive Symptoms in Cardiac Rehabilitation.THE JOURNAL OF SEXUAL MEDICINE, Issue 6 2010Findings of the SPARK Project in 493 Patients ABSTRACT Introduction., Empirical evidence suggests associations between cardiovascular diseases, sexual functioning, depressive symptoms, and quality of life. However, to date, the interrelation of these constructs has not been examined simultaneously in a structural analysis. Aim., To estimate the prevalence of sexual disorders and depressive symptoms and to examine the association between sexual disorders, depressive symptoms, and quality of life in patients in the rehabilitation of cardiovascular disorders. Aim., A postal survey in five German inpatient rehabilitation centers for cardiovascular diseases was conducted. Prevalence of sexual disorders and depressive symptoms were assessed using psychometrically sound instruments. To analyze complex associations, structural equation modeling was used. Main Outcome Measures., For epidemiological questions, proportions with 95% confidence intervals were calculated. The strength of association in structural equation models was expressed as a standardized regression coefficient. Results., Data from 493 patients were analyzed (response rate 22.7%). At least moderate erectile dysfunction proved to be present in 20.3% of men. The prevalence of female sexual dysfunction lay at 43.1%. At least moderate depressive symptoms were present in 14.4% of men and 16.5% of women. A considerable association between sexual functioning and quality of life was found in both sexes, which was largely mediated by depressive symptoms. Major drawbacks of the study are imprecision of the estimates due to limited sample size and questionable generalizability of the findings due to possible self-selection bias. Conclusions., Considering the high prevalence of depressive symptoms and their role as a mediating factor between sexual functioning and quality of life, it is recommended to routinely screen for depression in men and women with cardiac disease. Kriston L, Günzler C, Agyemang A, Bengel J, and Berner MM. Effect of sexual function on health-related quality of life mediated by depressive symptoms in cardiac rehabilitation. Findings of the SPARK project in 493 patients. J Sex Med 2010;7:2044,2055. [source] Comprehensive proteome analysis by chromatographic protein prefractionationELECTROPHORESIS, Issue 7-8 2004Pierre Lescuyer Abstract Protein copy number is distributed from 7 to 8 orders of magnitude in cells and probably up to 12 orders of magnitude in plasma. Classical silver-stained two-dimensional electrophoresis (2-DE) can only display up to four orders of magnitude. This is a major drawback since it is assumed that most of the regulatory proteins are low-abundance gene products. It is thus clear that the separation of low copy number proteins in amounts sufficient for postseparation analysis is an important issue in proteome studies to complete the comprehensive description of the proteome of any given cell type. The visualization of a polypeptide on a 2-DE gel will depend on the copy number, on the quantity loaded onto the gel and on the method of detection. As the amount of protein that can be loaded onto a gel is limited, one efficient solution is to fractionate the sample prior to 2-DE analysis. Several approaches exist including subcellular fractionation, affinity purification and chromatographic and electrophoretic protein prefractionation. The chromatographic step adds a new dimension in the protein separation using specific protein properties. It allows proteins to be adsorbed to a surface and eluted differentially under certain conditions. This review article presents studies combining chromatography-based methods to 2-DE analysis and draws general conclusions on this strategy. [source] Optimal Control of Rigid-Link Manipulators by Indirect MethodsGAMM - MITTEILUNGEN, Issue 1 2008Rainer Callies Abstract The present paper is a survey and research paper on the treatment of optimal control problems of rigid-link manipulators by indirect methods. Maximum Principle based approaches provide an excellent tool to calculate optimal reference trajectories for multi-link manipulators with high accuracy. Their major drawback was the need to explicitly formulate the complicated system of adjoint differential equations and to apply the full apparatus of optimal control theory. This is necessary in order to convert the optimal control problem into a piecewise defined, nonlinear multi-point boundary value problem. An accurate and efficient access to first- and higher-order derivatives is crucial. The approach described in this paper allows it to generate all the derivative information recursively and simultaneously with the recursive formulation of the equations of motion. Nonlinear state and control constraints are treated without any simplifications by transforming them into sequences of systems of linear equations. By these means, the modeling of the complete optimal control problem and the accompanying boundary value problem is automated to a great extent. The fast numerical solution is by the advanced multiple shooting method JANUS. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Validation of microarray-based resequencing of 93 worldwide mitochondrial genomes,HUMAN MUTATION, Issue 1 2009Anne Hartmann Abstract The human mitochondrial genome consists of a multicopy, circular dsDNA molecule of 16,569 base pairs. It encodes for 13 proteins, two ribosomal genes, and 22 tRNAs that are essential in the generation of cellular ATP by oxidative phosphorylation in eukaryotic cells. Germline mutations in mitochondrial DNA (mtDNA) are an important cause of maternally inherited diseases, while somatic mtDNA mutations may play important roles in aging and cancer. mtDNA polymorphisms are also widely used in population and forensic genetics. Therefore, methods that allow the rapid, inexpensive and accurate sequencing of mtDNA are of great interest. One such method is the Affymetrix GeneChip® Human Mitochondrial Resequencing Array 2.0 (MitoChip v.2.0) (Santa Clara, CA). A direct comparison of 93 worldwide mitochondrial genomes sequenced by both the MitoChip and dideoxy terminator sequencing revealed an average call rate of 99.48% and an accuracy of ,99.98% for the MitoChip. The good performance was achieved by using in-house software for the automated analysis of additional probes on the array that cover the most common haplotypes in the hypervariable regions (HVR). Failure to call a base was associated mostly with the presence of either a run of ,4,C bases or a sequence variant within 12 bases up- or downstream of that base. A major drawback of the MitoChip is its inability to detect insertions/deletions and its low sensitivity and specificity in the detection of heteroplasmy. However, the vast majority of haplogroup defining polymorphism in the mtDNA phylogeny could be called unambiguously and more rapidly than with conventional sequencing. Hum Mutat 0,1,8, 2008. © 2008 Wiley-Liss, Inc. [source] A control volume capacitance method for solidification modelling with mass transportINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 12 2002K. Davey Abstract Capacitance methods are popular methods used for solidification modelling. Unfortunately, they suffer from a major drawback in that energy is not correctly transported through elements and so provides a source of inaccuracy. This paper is concerned with the development and application of a control volume capacitance method (CVCM) to problems where mass transport and solidification are combined. The approach adopted is founded on theory that describes energy transfer through a control volume (CV) moving relative to the transporting mass. An equivalent governing partial differential equation is established, which is designed to be transformable into a finite element system that is commonly used to model transient heat-conduction problems. This approach circumvents the need to use the methods of Bubnov,Galerkin and Petrov,Galerkin and thus eliminates many of the stability problems associated with these approaches. An integration scheme is described that accurately caters for enthalpy fluxes generated by mass transport. Shrinkage effects are neglected in this paper as all the problems considered involve magnitudes of velocity that make this assumption reasonable. The CV approach is tested against known analytical solutions and is shown to be accurate, stable and computationally competitive. Copyright © 2002 John Wiley & Sons, Ltd. [source] Faecal screening of colorectal cancerINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 3 2008A. Loganayagam Summary Aims:, Screening and prevention of colorectal cancer (CRC) is a public health priority. Recent progress in understanding the biology of CRC has lead to possible new approaches to screening. In particular, assay of faecal molecular markers represents a promising non-invasive approach to screening, with improved safety, accuracy and patient compliance. Methods:, MEDLINE/PubMed searches were used to identify key articles relating to faecal-based screening with secondary review of cited publications. Results:, Faecal markers of CRC can be broadly divided into DNA based and non-DNA based. Conclusions:, Faecal occult blood testing for CRC screening has been advocated for decades for its non-invasiveness and low cost. It has exhibited a 15,33% decrease in mortality, despite drawbacks with sensitivity and compliance. Other non-DNA markers have the adequate sensitivity for inflammatory lesions but do not have the required specificity for screening average-risk populations. Faecal DNA testing has the potential to enhance the performance characteristics of stool testing. Because of molecular heterogeneity of cancer, no single DNA marker has yielded adequate sensitivity. Analysis of several combinations of markers in studies have produced high detection rates of both CRC and advanced adenomas in selected patient groups. However, the currently available markers, both non-DNA and DNA, have not yet been validated in large-scale studies screening average -risk population nor have they so far shown the necessary sensitivity and specificity required for large-scale screening programmes. Another major drawback with the DNA-based markers is the cost-effectiveness. Issues regarding implementation and compliance remain unanswered. These critical problems have to be rectified before these techniques can be recommended for large-scale CRC screening. [source] Clustering-based scheduling: A new class of scheduling algorithms for single-hop lightwave networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 8 2008Sophia G. Petridou Abstract In wavelength division multiplexing (WDM) star networks, the construction of the transmission schedule is a key issue, which essentially affects the network performance. Up to now, classic scheduling techniques consider the nodes' requests in a sequential service order. However, these approaches are static and do not take into account the individual traffic pattern of each node. Owing to this major drawback, they suffer from low performance, especially when operating under asymmetric traffic. In this paper, a new class of scheduling algorithms for WDM star networks, which is based on the use of clustering techniques, is introduced. According to the proposed Clustering-Based Scheduling Algorithm (CBSA), the network's nodes are organized into clusters, based on the number of their requests per channel. Then, their transmission priority is defined beginning from the nodes belonging to clusters with higher demands and ending to the nodes of clusters with fewer requests. The main objective of the proposed scheme is to minimize the length of the schedule by rearranging the nodes' service order. Furthermore, the proposed CBSA scheme adopts a prediction mechanism to minimize the computational complexity of the scheduling algorithm. Extensive simulation results are presented, which clearly indicate that the proposed approach leads to a significantly higher throughput-delay performance when compared with conventional scheduling algorithms. We believe that the proposed clustering-based approach can be the base of a new generation of high-performance scheduling algorithms for WDM star networks. Copyright © 2008 John Wiley & Sons, Ltd. [source] Heat transfer enhancement of fatty acids when used as PCMs in thermal energy storageINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 2 2008Muhsin Mazman Abstract Phase change materials (PCM) used in latent heat storage systems usually have very low thermal conductivities. This is a major drawback in maintaining the required heat exchange rate between PCM and heat transfer fluid. This paper investigates the enhancement of the heat transfer between PCM and heat transfer fluid, using high thermal conductivity as additives like stainless steel pieces, copper pieces and graphite,PCM composite material. In the experiments, palmitic,lauric acid (80:20) (PL) and stearic,myristic acid (80:20) (SM) were used as PCMs. Test results show that heat transfer enhancement of copper pieces was better at 0.05 Ls,1 flow rate compared to 0.025 Ls,1. Using copper as an additive increased the heat transfer rate 1.7 times for melting and 3.8 times for freezing when flow rate was 0.050 Ls,1. Decreasing the flow rate from 0.050 to 0.025 Ls,1, increased the melting times 1.3 times and freezing times 1.8 times, decreasing heat transfer rates accordingly. The best result of heat transfer enhancement was observed for the PCM,graphite composite. However, changing the flow rate did not affect the heat transfer rate when graphite was used as additive. Copyright © 2007 John Wiley & Sons, Ltd. [source] Separation of haemoglobin HbE and HbA2 by the fully automated, high-pressure liquid chromatography Tosoh HLC-723 G7 analyzerINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 5 2008G. LIPPI Summary High-pressure liquid chromatography instruments specifically devised for separating haemoglobin (Hb) fractions have been increasingly employed by the hospital laboratories over the recent years since they allow easy and fast screening for several Hb variants. Although such instruments may be proposed as sensitive, specific and reliable alternatives to the classic electrophoretic techniques, a major drawback of this screening strategy is the almost identical retention time of several Hb variants. In particular, at least 18 Hb variants have been reported in the same retention window as HbA2, including HbE, the second most common ,-chain variant in humans after sickle cell trait. Recently, we evaluated the performance characteristics of an improved buffer formulation originally conceived for Hb variants separation procedures on the fully automated high-pressure liquid chromatography instrument Tosoh G7. At variance with other fully automated high-pressure liquid chromatography analyzers, the elution pattern on the G7 in subjects heterozygous for HbE is characterized by the presence of four suggestive peaks (HbF, HbA, HbA2 and HbE), confirming the effective separation of HbE from HbA2. Because of its potential value in the diagnosis of the thalassaemia syndromes, the effective separation of HbA2 from HbE can provide clinical laboratories with a valuable information for the diagnostic reasoning. [source] Recent trends in the treatment of testosterone deficiency syndromeINTERNATIONAL JOURNAL OF UROLOGY, Issue 11 2007Bum Sik Hong Abstract: Testosterone deficiency syndrome (TDS) is defined as a clinical and biochemical syndrome associated with advancing age and is characterized by typical symptoms and deficiency in serum testosterone levels. TDS is a result of the interaction of hypothalamo-pituitary and testicular factors. Now, treatment of TDS with testosterone is still controversial due to a lack of large, controlled clinical trials on efficacy. The risks of treatment with testosterone appear to be minimal, although long-term studies on the safety of testosterone therapy are lacking. The aim of the therapy is to establish a physiological concentration of serum testosterone in order to correct the androgen deficiency, relieve its symptoms and prevent long-term sequelae. All of the available products, despite their varying pharmacodynamic and pharmacokinetic profiles, are able to reach this goal. Newer testosterone patches seem not to cause severe skin irritation. Testosterone gels minimize the skin irritation while providing flexibility in dosing and a low discontinuation rate. Oral testosterone undecanoate (TU) is free of liver toxicity. Recent formulation of oral TU markedly increased shelf-live, a major drawback in the older preparation. Producing swings in testosterone levels rising rapidly to the supraphysiological range is not the case with the new injectable long-acting preparation of TU. To be able to rapidly react and stop treatment in cases where side-effects and contraindications are detected, the short-acting transdermal and oral delivery modes have certain advantages. However, there is no evidence that the use of an injectable long-acting TU in men with TDS has limitations in clinical application for this reason. The use of dehydroepiandrosterone is still controversial because of a lack of well designed long-term trials, although some recent studies suggest positive effects on various body systems. Only a few studies have been carried out to investigate the effect of hCG (human chorionic gonadotropin) in TDS with some positive results on various body systems. [source] Slow programmable and ultra-rapid freezing of human embryosJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2008Teraporn Vutyavanich Abstract Aim:, To compare the outcomes of slow freezing with ultra-rapid freezing (URF) of cleavage-stage human embryos on aluminum foil. Methods:, Two-cell mouse embryos were used to test our method of ultra-rapid freezing. The embryos were randomly allocated to a non-frozen control (208 embryos), and slow (204 embryos) or ultra-rapid freezing groups (204 embryos). Immediate survival rate, further cleavage and blastocyst formation were compared. After validating our ultra-rapid freezing method on mouse embryos, we applied a similar ultra-rapid freezing protocol to human embryos. Consecutive human frozen/thawed embryo transfer (FET) cycles from October 1998 to June 2005 were reviewed. The survival rate, further cleavage rate and the pregnancy outcomes were compared between the URF and slow programmable freezing. Results:, Mouse embryos in the URF group survived the freezing/thawing process better than those in the slow freezing group (93.1% vs 82.8%, P = 0.001). Blastocyst and hatching blastocyst formation of the surviving embryos were comparable in the URF and slow freezing group (59% vs 58.6%, P = 0.944 and 32.6% vs 42%, P = 0.066, respectively). There were 146 human FET cycles in the URF group and 28 cycles in the slow freezing group. The immediate survival of embryos was higher in the URF group than in the slow freezing group (87.9% and 64.3%, P < 0.001). There was no significant difference in the mean number of embryos per transfer (3.7 ± 1.3 and 3.3 ± 1.2, P = 0.178), clinical pregnancy rate per transfer (28.5% and 21.4%, P = 0.444) and implantation rate per embryo (10.98% and 10.9%, P = 0.974) in the URF or slow freezing groups. Conclusion:, Our in-house URF method gave comparable results to slow programmable freezing. Although the risk of potential contamination is a major drawback of the present ultra-rapid freezing technique, future refinement will minimize or entirely eliminate this concern. [source] Fentanyl reduces desflurane-induced airway irritability following thiopental administration in childrenACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2006J. Lee Background:, Airway irritation is a major drawback of desflurane anesthesia. This study was designed to evaluate the effect of intravenous fentanyl given before thiopental induction on airway irritation caused by a stepwise increase in desflurane in children. Methods:, Eighty children (2,8 years) were enrolled in a randomized, double-blind study. Forty received saline and 40 received 2 ,g/kg of fentanyl intravenously; this was followed by thiopental sodium 5 mg/kg in both groups. Patients were assistant-ventilated with desflurane 1%, which was then increased by 1% every six breaths up to 10%. During this period, cough, secretion, excitation and apnea were graded and the desflurane concentration at which airway irritation symptoms first occurred was recorded. The results were analyzed using Pearson's chi-squared test. Results:, The incidence of typical airway irritation events was lower with fentanyl than with saline (cough, 2.5% vs. 42.5%; secretion, 27.5% vs. 82.5%; excitation, 10% vs. 82.5%; apnea, 20% vs. 65%; P < 0.05). The mean expired desflurane concentration at which the first airway irritation symptom occurred was greater with fentanyl than with saline (7.3% vs. 5.5%, P < 0.05). Conclusions:, Intravenous fentanyl in children reduces airway complications caused by desflurane. [source] Review article: success and failure of nucleoside and nucleotide analogues in chronic hepatitis BALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 2007W. F. LEEMANS SUMMARY Background, Strong suppression of viral replication and normalization of alanine aminotransferase is feasible with nucleos(t)ide analogues. It is estimated viral replication and liver inflammation can be controlled in 90% of patients with chronic hepatitis B with the current available treatments. Aim, To review the studies currently available on the management of chronic hepatitis B with nucleos(t)ide analogues. Results, Although very potent, nucleos(t)ide analogues are not effective in every patient. Some factors are known to influence treatment outcome, but many host and viral factors are still unknown. Stopping rules have to be defined to assess treatment efficacy in an early stage and change the regimen. Discontinuation of nucleos(t)ide analogues is often followed by reactivation of HBV. Data on the risk factors for relapse are necessary in order to decide if treatment can be safely discontinued. Another major drawback of nucleos(t)ide analogues is the emergence of resistance. The efficacy of compounds for the treatment of mutant virus and the impact of cross-resistance is largely unknown. The use of combination therapy to prevent resistance looks promising, but has to be proven. Conclusions, HBV has become a treatable disease, however much research is needed to optimize treatment for individual patients and treatment failures. [source] An AFLP clock for absolute dating of shallow-time evolutionary history , too good to be true?MOLECULAR ECOLOGY, Issue 22 2009D. EHRICH A major drawback of Amplified Fragment Length Polymorphisms (AFLP) as genetic makers for phylogeographic studies is their lack of a temporal dimension. In a recent publication in Molecular Ecology, Kropf et al. (2009) proposed a molecular clock for AFLP. In this comment we evaluate the proposed approach both theoretically and empirically. A linear increase with time is a prerequisite to use a genetic distance as molecular clock. Testing the relationship between genetic distance and time in the data of Kropf et al. (2009) for linearity revealed that the relationship was in fact not linear for their pooled data, as well as for one of the three species analyzed. Also, the relationship was not linear in two new species, where divergence times could be inferred from macrofossils. When applying the proposed molecular clock to data from eight species, dates obtained were plausible in some cases, but very improbable in others. The suggested genetic distance was also influenced by intrapopulation genetic diversity, leading to a potential bias. In the future, investigations of AFLP mutation rates combined with phylogeographic modelling may contribute to adding a time scale to the understanding of AFLP data. [source] Manganese-enhanced magnetic resonance imaging (MEMRI): methodological and practical considerationsNMR IN BIOMEDICINE, Issue 8 2004Afonso C. Silva Abstract Manganese-enhanced MRI (MEMRI) is being increasingly used for MRI in animals due to the unique T1 contrast that is sensitive to a number of biological processes. Three specific uses of MEMRI have been demonstrated: to visualize activity in the brain and the heart; to trace neuronal specific connections in the brain; and to enhance the brain cytoarchitecture after a systemic dose. Based on an ever-growing number of applications, MEMRI is proving useful as a new molecular imaging method to visualize functional neural circuits and anatomy as well as function in the brain in vivo. Paramount to the successful application of MEMRI is the ability to deliver Mn2+ to the site of interest at an appropriate dose and in a time-efficient manner. A major drawback to the use of Mn2+ as a contrast agent is its cellular toxicity. Therefore, it is critical to use as low a dose as possible. In the present work the different approaches to MEMRI are reviewed from a practical standpoint. Emphasis is given to the experimental methodology of how to achieve significant, yet safe, amounts of Mn2+ to the target areas of interest. Copyright © 2004 John Wiley & Sons, Ltd. [source] Effect of maleated polypropylene and impact modifiers on the morphology and mechanical properties of PP/Mica compositesPOLYMER COMPOSITES, Issue 6 2006H. Yazdani Composites of polypropylene (PP) with mica powder and impact modifiers were produced by internal mixer. A major drawback in the use of mica-filled PP is its low impact resistance. In the present study, the effect of the maleated PP (MAPP) and impact modifiers was evaluated on the composite properties separately and together. Thus, two different styrene-ethylene/butylene-styrene triblock copolymers (SEBS) and one ethylene-propylene-diene terpolymer (EPDM) have been used as impact modifiers in the PP-mica composites. Addition of MAPP had a negative effect on the composite notched impact strength and elongation at break but had a positive effect on tensile strength when used together with impact modifiers. All three elastomers increased the impact strength of the PP-mica composites but the addition of maleated SEBS (SEBS-MA) granted the greatest improvement in impact strength. It was inferred from the scanning electron microscopy that SEBS-MA had a stronger interaction with mica surface than the other impact modifiers. POLYM. COMPOS., 27:614,620, 2006. © 2006 Society of Plastics Engineers [source] Etiologic yield of autistic spectrum disorders: A prospective studyAMERICAN JOURNAL OF MEDICAL GENETICS, Issue 1 2006Agatino Battaglia Abstract Studies addressing etiologic yield in childhood developmental disabilities have mainly looked at individuals with developmental delay/mental retardation. The few studies addressing the question of etiologic yield in patients with pervasive developmental disorders (PDDs) had a major drawback, in that the enrolled subjects were diagnosed as having the autistic spectrum disorders based only on history and clinical examination, and/or on unspecified instruments. In addition, only some of these patients underwent a complete laboratory evaluation. To investigate the etiologic yield of PDDs, we undertook a large prospective study on subjects selected according to very strict criteria and diagnosed as having PDD based on the present "gold standard" (ADI-R and ADOS-G), and a clinical diagnosis made by a child psychiatrist. Eighty-five (85) patients with PDD and their first degree relatives participated in this study. These patients were selected from a sample of 236 subjects who had received a clinical diagnosis of PDD at the Stella Maris Institute between March 2002 and 2005. Selection criteria for entering the study were: (1) a diagnosis of PDD (with exclusion of the Rett syndrome) confirmed after the administration of the ADI-R (autism diagnostic interview-revised) and the ADOS-G (autism diagnostic observation schedule-generic). In addition, a clinical diagnosis was made by the child psychiatrist, on the basis of presence or absence of DSM-IV symptoms of autism; (2) chronological age between 4 and 18 years; (3) IQ>30; (4) availability of both biologic parents. Patients, 65/85 (76.5%), had autism, 18/85 (21.2%) had PDD-NOS, and the remaining 2/85 (2.3%) had Asperger syndrome. Ages varied between 4 years 2 months and 12 years 5 months (mean 7.6 years), and there was a marked male preponderance (68/85). All subjects underwent various laboratory studies and neuroimaging. With respect to possible etiologic determination, a detailed history and physical examination in this group of patients with PDD was informative in 10.5% (9/85). HRB karyotype was diagnostic in one, and molecular fragile X studies in one child. Brain MRI was informative in two children (2.3%) with relative macrocrania but no neurological features; and EEG was helpful in one child, identifying a Landau,Kleffner disorder. Audiometry and brainstem auditory evoked potentials (BAEPs) showed a bilateral sensorineural loss in another child. Metabolic evaluation gave normal results in all subjects. The results suggest an evaluation paradigm with reference to etiologic determination for individuals with PDDs that does not presently justify metabolic or neuroimaging on a screening basis. Recurrence risk, treatment implications, and significant and long-lasting emotional relief for the parents suggest that serious consideration be given to clinical genetic examination, genetic testing, EEG study (during wakefulness and sleep), and audiometry, despite a relatively low yield. © 2006 Wiley-Liss, Inc. [source] Fish proteome analysis: Model organisms and non-sequenced speciesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 4 2010Ignasi Forné Abstract In the last decade, proteomic technologies have been increasingly used in fish biology research. Proteomics has been applied primarily to investigate the physiology, development biology and the impact of contaminants in fish model organisms, such as zebrafish (Danio rerio), as well as in some commercial species produced in aquaculture, mainly salmonids and cyprinids. However, the lack of previous genetic information on most fish species has been a major drawback for a more general application of the different proteomic technologies currently available. Also, many teleosts of interest in biological research and with potential application in aquaculture hold unique physiological characteristics that cannot be directly addressed from the study of small laboratory fish models. This review describes proteomic approaches that have been used to investigate diverse biological questions in model and non-model fish species. We will also evaluate the current possibilities to integrate fish proteomics with other "omic" approaches, as well as with additional complementary techniques, in order to address the future challenges in fish biology research. [source] Serologic screening for celiac disease in children: a comparison between established assays and tests with deamidated gliadin-derived peptides plus conjugates for both IgA and IgG antibodiesAPMIS, Issue 11 2009ANNA-KARIN ĹBERG Selection of patients for diagnostic biopsy concerning celiac disease (CD) is mainly guided by the results with serological screening tests like anti-tissue-transglutaminase (tTG), anti-endomysium (EmA) and anti-gliadin (AGA) IgA. New tests using deamidated gliadin-derived peptides (DGP) including both IgA and IgG antibodies have been developed, to cover the IgA-deficient sera. In addition, a combined IgA and IgG DGP test, with or without human erythrocyte-derived tTG, offers possible advantages. In order to explore the screening accuracy of the new combination tests sera from 167 children below 3 years of age were assayed. Biopsy had been taken in connection with serology in 32 of these children, 24 with histopathological CD. The results with the DGP and the combined test were congruent with the IgA antibody tests for tTG, EmA and AGA, all identifying 21 of 24 of the CD cases. Two of the CD patients were AGA-IgA positive only (2/24), while 2 of 24 sera were AGA,IgA negative but positive in all the other tests. These results raises the question whether the modifications of the gliadin antigen not only decrease false positivity but also give more false-negative results, a major drawback for a screening test for an important disease. Further studies have to be undertaken to explore this. Our results also stress that serologic screening of CD in children cannot be based on one test only. [source] A population analysis of VEGF transgene expression and secretionBIOTECHNOLOGY & BIOENGINEERING, Issue 5 2008Golnaz Karoubi Abstract The induction of therapeutic angiogenesis with gene therapy approaches has received considerable interest and some limited clinical success. A major drawback to this approach is a lack of understanding of the pharmacokinetics of therapeutic protein delivery. This has become increasingly more relevant as recent studies have illustrated a defined therapeutic window for angiogenic protein secretion into the local microenvironment. For cell based gene therapies, with cells widely distributed throughout the tissue, this implies that any individual cell must attain a specific secretion rate to produce a local angiogenic response. Here we report a reproducible technique enabling the study of growth factor secretion from individual cells following transient plasmid transfection. We demonstrate significant variability in single cell vascular endothelial growth factor (VEGF) secretion with the majority of total protein secretion arising from a small subpopulation of transfected cells. We demonstrate that VEGF secretion is linearly correlated to intracellular plasmid copy number and protein secretion does not appear to reach saturation within the cell population. The selection of gene therapy approaches that optimize individual cell secretion profiles may be essential for the development of effective gene therapies. Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc. [source] Scalping of Flavors in Packaged FoodsCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2007M.G. Sajilata ABSTRACT:, Food packaging, although an integral part of the food chain, has a major drawback in that, often, the packaging material interacts with the flavor constituents of the food, causing either a selective or an extensive loss of desirable food flavors or absorption of undesirable off-flavors from the packaging material, thereby resulting in an eventual loss of quality of the packaged food item. The process is called "scalping" and is of great concern to the food industry, which is always looking out for new avenues in "packaging solutions" for its final product quality needs. The review highlights the various attributes of the scalping process, explores approaches to the reduction of the manifested undesirable effects, and covers other relevant aspects. [source] Pedestrian Reactive Navigation for Crowd Simulation: a Predictive ApproachCOMPUTER GRAPHICS FORUM, Issue 3 2007Sébastien Paris This paper addresses the problem of virtual pedestrian autonomous navigation for crowd simulation. It describes a method for solving interactions between pedestrians and avoiding inter-collisions. Our approach is agent-based and predictive: each agent perceives surrounding agents and extrapolates their trajectory in order to react to potential collisions. We aim at obtaining realistic results, thus the proposed model is calibrated from experimental motion capture data. Our method is shown to be valid and solves major drawbacks compared to previous approaches such as oscillations due to a lack of anticipation. We first describe the mathematical representation used in our model, we then detail its implementation, and finally, its calibration and validation from real data. [source] A smooth switching adaptive controller for linearizable systems with improved transient performanceINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 9 2006Jeng Tze Huang Abstract The certainty equivalent control has achieved asymptotic tracking stability of linearizable systems in the presence of parametric uncertainty. However, two major drawbacks remain to be tackled, namely, the risk of running into singularity for the calculated control input and the poor transient behaviour arising frequently in a general adaptive system. For the first problem, a high gain control is activated in place of the certainty equivalent control until the risk is bypassed. Among others, it requires less control effort by taking advantages of the bounds for the input vector field. Moreover, the switching mechanism is smooth and hence avoids possible chattering behaviour. Next, to solve the second problem, a new type of update algorithm guaranteeing the exponential stability of the overall closed-loop system, on a weaker persistent excitation (PE) condition, is proposed. In particular, it requires no filtering of the regressor and hence is easier to implement. Simulation results demonstrating the validity of the proposed design are given in the final. Copyright © 2006 John Wiley & Sons, Ltd. [source] Effects of cationic polymer on start-up and granulation in upflow anaerobic sludge blanket reactorsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2004Ying Wang Abstract The upflow anaerobic sludge blanket (UASB) has been used successfully to treat a variety of industrial wastewaters. It offers a high degree of organics removal, low sludge production and low energy consumption, along with energy production in the form of biogas. However, two major drawbacks are its long start-up period and deficiency of active biogranules for proper functioning of the process. In this study, the influence of a coagulant polymer on start-up, sludge granulation and the associated reactor performance was evaluated in four laboratory-scale UASB reactors. A control reactor (R1) was operated without added polymer, while the other three reactors, designated R2, R3 and R4, were operated with polymer concentrations of 5 mg dm,3, 10 mg dm,3 and 20 mg dm,3, respectively. Adding the polymer at a concentration of 20 mg dm,3 markedly reduced the start-up time. The time required to reach stable treatment at an organic loading rate (OLR) of 4.8 g COD dm,3 d,1 was reduced by more than 36% (R4) as compared with both R1 and R3, and by 46% as compared with R2. R4 was able to handle an OLR of 16 g COD dm,3 d,1 after 93 days of operation, while R1, R2 and R3 achieved the same loading rate only after 116, 116 and 109 days respectively. Compared with the control reactor, the start-up time of R4 was shortened by about 20% at this OLR. Granule characterization indicated that the granules developed in R4 with 20 mg dm,3 polymer exhibited the best settleability and methanogenic activity at all OLRs. The organic loading capacities of the reactors were also increased by the addition of polymer. The maximum organic loading of the control reactor (R1) without added polymer was 19.2 g COD dm,3 d,1, while the three polymer-assisted reactors attained a marked increase in organic loading of 25.6 g COD dm,3 d,1. Adding the cationic polymer could result in shortening of start-up time and enhancement of granulation, which may in turn lead to improvement in the efficiency of organics removal and loading capacity of the UASB system. Copyright © 2004 Society of Chemical Industry [source] How much effort is required to isolate nuclear microsatellites from plants?MOLECULAR ECOLOGY, Issue 6 2003J. Squirrell Abstract The attributes of codominance, reproducibility and high resolution have all contributed towards the current popularity of nuclear microsatellites as genetic markers in molecular ecological studies. One of their major drawbacks, however, is the development phase required to obtain working primers for a given study species. To facilitate project planning, we have reviewed the literature to quantify the workload involved in isolating nuclear microsatellites from plants. We highlight the attrition of loci at each stage in the process, and the average effort required to obtain 10 working microsatellite primer pairs. [source] Monitoring angiogenesis in soft-tissue engineered constructs for calvarium bone regeneration: an in vivo longitudinal DCE-MRI studyNMR IN BIOMEDICINE, Issue 1 2010Marine Beaumont Abstract Tissue engineering is a promising technique for bone repair and can overcome the major drawbacks of conventional autogenous bone grafting. In this in vivo longitudinal study, we proposed a new tissue-engineering paradigm: inserting a biological soft-tissue construct within the bone defect to enhance angiogenesis for improved bone regeneration. The construct acts as a resorbable scaffold to support desired angiogenesis and cellular activity and as a vector of vascular endothelial growth factor, known to promote both vessel and bone growth. Dynamic contrast- enhanced magnetic resonance imaging was performed to investigate and characterize angiogenesis necessary for bone formation following the proposed paradigm of inserting a VEGF-impregnated tissue-engineered construct within the critical-sized calvarial defect in the membranous parietal bone of the rabbit. Results show that a model-free quantitative approach, the normalized initial area under the curve metric, provides sensitive and reproducible measures of vascularity that is consistent with known temporal evolution of angiogenesis during bone regeneration. Copyright © 2009 John Wiley & Sons, Ltd. [source] Optimised Plasma Absorption Probe for the Electron Density Determination in Reactive PlasmasPLASMA PROCESSES AND POLYMERS, Issue 1 2009Christian Scharwitz Abstract The plasma absorption probe (PAP) is a recently developed tool for the efficient determination of electron densities, especially in reactive plasmas. A dielectric cover protects this probe against the influences in reactive plasmas and it withstands conditions where Langmuir probes are easily damageable. The lack of adequate calibration constants and the occurrence of multiple absorption signals were two major drawbacks, which are successfully overcome in this work. Design variations are tested by numerical computation and the model-based achievements are established in experiment. In this work, a redesigned PAP is presented, which is optimised for the easy determination of electron densities. The developed tool works fast and efficiently, in particular in discharges in reactive gases. [source] Bis (ortho -) chelated Monoanionic Bisphosphinoaryl Ruthenium (II) Complexes: Synthesis, Characterization and Reactivity,CHINESE JOURNAL OF CHEMISTRY, Issue 3 2002Gerard P. M. Klink Abstract Bisphosphinoaryl ruthenium (II) compounds are synthesized using two distinct synthetic routes. One route, direct cycloruthenation, consists of the reaction of the parent arene compound R-PCHP with [RuCl2 (PPh3)3] in chlorinated solvents. However, this route suffers from major drawbacks because HCl is formed as well as free triphenylphoshine. The other route, the transcyclometalation reaction, involves the interconversion of one cyclometalated ligand metal complex, [RuCl (NCN) (PPh3)], into another complex, [RuCl (R-PCP) (PPh3)], with concomitant consumption and formation of the corresponding arenes R-PCHP and NCHN, respectively. [source] | |||||||||||||||||||||||||