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Selected AbstractsHow to make a zone of polarizing activity: Insights into limb development via the abnormality preaxial polydactylyDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 6 2007Robert E. Hill Early in vertebrate limb development, a program initiates that polarizes the limb along the antero-posterior axis. The mesenchyme at the posterior margin is ultimately responsible for the asymmetry due to a region called the zone of polarizing activity (ZPA). The ZPA produces and secretes the molecule SHH, which coordinates the patterning of the resulting digits. Preaxial polydactyly (PPD) is a commonly occurring limb abnormality; investigating the genetic basis of this defect has provided insights into our understanding of digit patterning. PPD disrupts limb asymmetry by producing an ectopic ZPA at the opposite margin of the limb bud. Mutations in the long-range, limb-specific regulatory element of the Shh gene are responsible for the defect. Genetic analysis of this limb abnormality provides an important approach in understanding the mechanisms that control digit patterning. [source] Evaluation of coalbed methane reservoirs from geophysical log data using an improved fuzzy comprehensive decision method and a homologous neural networkGEOPHYSICAL PROSPECTING, Issue 5 2002J. Hou The evaluation of coalbed methane reservoirs using log data is an important approach in the exploration and development of coalbed methane reservoirs. Most commonly, regression techniques, fuzzy recognition and neural networks have been used to evaluate coalbed methane reservoirs. It is known that a coalbed is an unusual reservoir. There are many difficulties in using regression methods and empirical qualitative recognition to evaluate a coalbed, but fuzzy recognition, such as the fuzzy comprehensive decision method, and neural networks, such as the back-propagation (BP) network, are widely used. However, there are no effective methods for computing weights for the fuzzy comprehensive decision method, and the BP algorithm is a local optimization algorithm, easily trapped in local minima, which significantly affect the results. In this paper, the recognition method for coal formations is developed; the improved fuzzy comprehensive decision method, which uses an optimization approach for computing weighted coefficients, is developed for the qualitative recognition of coalbed methane reservoirs. The homologous neural network, using a homologous learning algorithm, which is a global search optimization, is presented for the quantitative analysis of parameters for coalbed methane reservoirs. The applied procedures for these methods and some problems related to their application are also discussed. Verification of the above methods is made using log data from the coalbed methane testing area in North China. The effectiveness of the methods is demonstrated by the analysis of results for real log data. [source] Comparing and evaluating process-based ecosystem model predictions of carbon and water fluxes in major European forest biomesGLOBAL CHANGE BIOLOGY, Issue 12 2005Pablo Morales Abstract Process-based models can be classified into: (a) terrestrial biogeochemical models (TBMs), which simulate fluxes of carbon, water and nitrogen coupled within terrestrial ecosystems, and (b) dynamic global vegetation models (DGVMs), which further couple these processes interactively with changes in slow ecosystem processes depending on resource competition, establishment, growth and mortality of different vegetation types. In this study, four models , RHESSys, GOTILWA+, LPJ-GUESS and ORCHIDEE , representing both modelling approaches were compared and evaluated against benchmarks provided by eddy-covariance measurements of carbon and water fluxes at 15 forest sites within the EUROFLUX project. Overall, model-measurement agreement varied greatly among sites. Both modelling approaches have somewhat different strengths, but there was no model among those tested that universally performed well on the two variables evaluated. Small biases and errors suggest that ORCHIDEE and GOTILWA+ performed better in simulating carbon fluxes while LPJ-GUESS and RHESSys did a better job in simulating water fluxes. In general, the models can be considered as useful tools for studies of climate change impacts on carbon and water cycling in forests. However, the various sources of variation among models simulations and between models simulations and observed data described in this study place some constraints on the results and to some extent reduce their reliability. For example, at most sites in the Mediterranean region all models generally performed poorly most likely because of problems in the representation of water stress effects on both carbon uptake by photosynthesis and carbon release by heterotrophic respiration (Rh). The use of flux data as a means of assessing key processes in models of this type is an important approach to improving model performance. Our results show that the models have value but that further model development is necessary with regard to the representation of the some of the key ecosystem processes. [source] IDENTIFICATION OF CRITICAL CONTROL POINTS IN THE TWO SELECTED HACCP-CERTIFIED PRAWN PROCESSING UNITSJOURNAL OF FOOD QUALITY, Issue 2 2009PADMAJA R. JONNALAGADDA ABSTRACT A study on identification of critical control points in two export processing units indicated the contamination (cfu/g) of raw prawns with pathogenic fecal coliforms was <10,8 × 102 in Unit A, 1 × 101,1.3 × 102 in Unit B and 1 × 103,4 × 104 in pond to plate. The other microbial contaminants in Unit A and from Pond to Plate at different stages were Salmonella spp., 3 × 102,5.7 × 103 and 2 × 102,6 × 102; Staphylococcus aureus, 1.7 × 103,5.7 × 103 and 1 × 103 to 9 × 104; and Vibrio parahaemolyticus, 3 × 102,2 × 104 and 3 × 104,5 × 104, respectively. However, microbial contamination was significantly reduced to <10 after subjecting to household cooking process. PRACTICAL APPLICATIONS Implementation of hazard analysis critical control points (HACCPs) in the food industry is the most important approach to maintaining food safety. Identification of the critical control points in the HACCPs process will help the aquaculture industry to improve its production processes by applying good aquaculture and good hygienic practices at the production level. The study further provides clear insights into identifying critical control points both at the farm level and at the processing units that are important from farm to fork. [source] Induction of dendritic cell-mediated immune responses against HIV-1 by antigen-capturing nanospheres in miceJOURNAL OF MEDICAL VIROLOGY, Issue 1 2005Masaki Kawamura Abstract Prophylactic vaccines, designed to elicit potent humoral and cellular immune responses to human immunodeficiency virus type 1 (HIV-1) antigens in mucosa, are the important approach to the protection of individuals against HIV-1 infection, since HIV-1 transmission is largely a result of sexual contact. In this study, a novel strategy has been developed to induce HIV-1-specific immune responses, which involves inactivated HIV-1-caputring concanavalin A (Con A)-immobilized nanospheres (HIV-NS) and their interaction with bone marrow (BM)-derived dendritic cells. HIV-NS were taken up by dendritic cells via cytoskeleton-dependent but mannose-binding site-independent phagocytosis. Serial stimulations to unprimed T-cells with HIV-1 gp120-capturing NS-pulsed dendritic cells could induce antigen-specific T-cell response. Intranasal administration of fluorescein isothiocyanate-labeled nanospheres (NS) in mice proved that the particles were taken up into pulmonary dendritic cells. Analysis of mice receiving intranasal immunizations with HIV-NS revealed that the mice efficiently induced the antibodies against HIV-1 in the genital tract and specific cytotoxic T-cells in the spleen. These results suggest that the use of HIV-1-NS may provide a novel and promising approach for the induction of humoral and cellular immune responses to HIV-1. J. Med. Virol. 76:7,15, 2005. © 2005 Wiley-Liss, Inc. [source] Struggling with an unfamiliar and unreliable body: the experience of irritable bowel syndromeJOURNAL OF NURSING AND HEALTHCARE OF CHRONIC ILLNE SS: AN INTERNATIONAL INTERDISCIPLINARY JOURNAL, Issue 1 2009Cecilia Håkanson MSc Aim., To describe the phenomenon living with irritable bowel syndrome from a life-world perspective. Background., Ten to twenty per cent of the adult population in the world is known to live with irritable bowel syndrome. The life-world experience of people with irritable bowel syndrome has been paid little attention. A deeper understanding about the phenomenon living with irritable bowel syndrome is of interest for the future development of care. Design and methods., The study was performed using a phenomenological method. Data was collected by in-depth, open interviews performed in 2006, with nine persons between 25,55 years, diagnosed with irritable bowel syndrome. The interviews were analysed according to the method of Giorgi. Results., Six interrelated key constituents have been identified: Having an altered self-image, feeling ashamed, distrusting the body, feeling tired, blaming oneself, and finding solutions. A structure has been formulated, describing that living with irritable bowel syndrome means struggling with an unfamiliar and unreliable body. Tiredness, distrust, and feelings of shame towards the body bring about limitations in everyday life. At the same time, living with irritable bowel syndrome means having a strong will to exceed the limitations and become familiar with one self. Conclusion., This study suggests that living with irritable bowel syndrome means to struggle with an unfamiliar and unreliable body that brings about changes of self-image and limitations in every day life. Feelings of distrust, shame and embarrassment towards troublesome symptoms, are important contributions to the limitations experienced. Relevance to clinical practice., Nurses have a major role to play in the care for people with irritable bowel syndrome. A caring perspective, in which the life-world is central, is an important approach to care for these persons. Using the dialogue as a forum where patients can share their unique life-world experiences lets nurses gather knowledge that is essential in helping patients identify and acknowledge new and positive understandings of the lived body. [source] Histomorphometry of brain tumoursNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 4 2004R. Nafe In this review, the results of previous histomorphometric studies of brain tumours are summarized and discussed with respect to their potential value for diagnostic purposes and for tumour research. In the majority of these studies, human gliomas were investigated. In a few studies, human meningiomas and other human or experimental tumour types were investigated. A computerized image analysis system was used for the morphometric analyses in most studies. The three main histologic structures examined were tumour cell nuclei, nucleolar organizer regions and tumour vessels. The current state of knowledge provides evidence that a diagnostic benefit could be provided by histomorphometric investigations of brain tumours, especially for grading of gliomas and with respect to independent prognostic information. Additional studies are necessary to delineate the spectrum of histomorphometric parameters and the investigation of their prognostic significance for cases with the same tumour type and tumour grade. Together with many recently published observations in this field, this review shows that histomorphometry is an important approach towards the investigation of brain tumour biology. [source] DNA copy number alterations in prostate cancers: A combined analysis of published CGH studiesTHE PROSTATE, Issue 7 2007Jishan Sun Abstract BACKGROUND Identifying genomic regions that are commonly deleted or gained in neoplastic cells is an important approach to identify tumor suppressor genes and oncogenes. Studies in the last two decades have identified a number of common DNA copy number alterations in prostate cancer. However, because of various sample sizes, diverse tumor types and sources, as well as a variety of detection methods with various sensitivities and resolutions, it is difficult to summarize and fully interpret the overall results. METHODS We performed a combined analysis of all published comparative genomic hybridization (CGH) studies of prostate cancer and estimated the frequency of alterations across the genome for all tumors, as well as in advanced and localized tumors separately. A total of 41 studies examining 872 cancers were included in this study. RESULTS The frequency of deletions and gains were estimated in all tumors, as well as in advanced and localized tumors. Eight deleted and five gained regions were found in more than 10% of the prostate tumors. An additional six regions were commonly deleted and seven were commonly gained in advanced tumors. While 8p was the most common location of deletion, occurring in about a third of all tumors and about half of advanced tumors, 8q was the most commonly gained region, affecting about a quarter of all tumors and about half of all advanced tumors. CONCLUSIONS The large number of tumors examined in this combined analysis provides better estimates of the frequency of specific alterations in the prostate cancer cell genome, and offers important clues for prioritizing efforts to identify tumor suppressor genes and oncogenes in these altered regions. Prostate 67: 692,700, 2007. © 2007 Wiley-Liss, Inc. [source] ON SOCIAL LEARNING AND ROBUST EVOLUTIONARY ALGORITHM DESIGN IN THE COURNOT OLIGOPOLY GAMECOMPUTATIONAL INTELLIGENCE, Issue 2 2007Floortje Alkemade Agent-based computational economics (ACE) combines elements from economics and computer science. In this article, the focus is on the relation between the evolutionary technique that is used and the economic problem that is modeled. In the field of ACE, economic simulations often derive parameter settings for the genetic algorithm directly from the values of the economic model parameters. This article compares two important approaches that are dominating in ACE and shows that the above practice may hinder the performance of the genetic algorithm and thereby hinder agent learning. More specifically, it is shown that economic model parameters and evolutionary algorithm parameters should be treated separately by comparing the two widely used approaches to social learning with respect to their convergence properties and robustness. This leads to new considerations for the methodological aspects of evolutionary algorithm design within the field of ACE. [source] Cytologic feature by squash preparation of pineal parenchyma tumor of intermediate differentiationDIAGNOSTIC CYTOPATHOLOGY, Issue 10 2008Keiji Shimada M.D., Ph.D. Abstract Pineal parenchyma tumor of intermediate differentiation (PPTID) is a very rare intracranial tumor, and pathological investigation limited to immunohistological and ultrastructural analyses have been published to date. Although intraoperative cytology is one of the important approaches for initial diagnosis in brain tumors, no or little studies on cellular morphology of PPTID have been demonstrated due to its rarity. We report here cytological features of PPTID obtained from stereotactic surgical specimens in a case of 27-year-old female manifested by dizziness and diplopia. Brain MRI revealed an unhomogeneously enhanced, large-sized tumor (56 × 52 × 60 mm) mainly located in the pineal region expanding from the midbrain to superior portion of the cerebellum and the fourth ventricle. Squash cytology showed increased nucleocytoplasmic ratio, hyperchromatic nuclei, and small rosette-like cell cluster but cellular pleomorphism was mild to moderate and necrotic background was not observed. Histology showed high cellularity, moderate nuclear atypia, and small rosette formation but neither bizarre tumor cells nor necrosis was present. Mitotic counts were very low (less than 1 per 10 high-power fields) and the MIB-1 labeling index was relatively high (10.1%). Tumor cells were immunohistochemically positive for neural markers such as synaptophysin, neurospecific enolase but not for glial fibrillary acidic protein or S-100. In some parts, cells were strongly reactive for neurofilament protein. Taken together, we made a final diagnosis of PPTID. This is the first presentation of cytological analysis by squash preparation that gives an important clue to accurate diagnosis of pineal parenchymal tumor and to understand its malignant potential. Diagn. Cytopathol. 2008;36:749,753. © 2008 Wiley-Liss, Inc. [source] Predictive toxicogenomics approaches reveal underlying molecular mechanisms of nongenotoxic carcinogenicityMOLECULAR CARCINOGENESIS, Issue 12 2006Alex Y. Nie Toxicogenomics technology defines toxicity gene expression signatures for early predictions and hypotheses generation for mechanistic studies, which are important approaches for evaluating toxicity of drug candidate compounds. A large gene expression database built using cDNA microarrays and liver samples treated with over one hundred paradigm compounds was mined to determine gene expression signatures for nongenotoxic carcinogens (NGTCs). Data were obtained from male rats treated for 24 h. Training/testing sets of 24 NGTCs and 28 noncarcinogens were used to select genes. A semiexhaustive, nonredundant gene selection algorithm yielded six genes (nuclear transport factor 2, NUTF2; progesterone receptor membrane component 1, Pgrmc1; liver uridine diphosphate glucuronyltransferase, phenobarbital-inducible form, UDPGTr2; metallothionein 1A, MT1A; suppressor of lin-12 homolog, Sel1h; and methionine adenosyltransferase 1, alpha, Mat1a), which identified NGTCs with 88.5% prediction accuracy estimated by cross-validation. This six genes signature set also predicted NGTCs with 84% accuracy when samples were hybridized to commercially available CodeLink oligo-based microarrays. To unveil molecular mechanisms of nongenotoxic carcinogenesis, 125 differentially expressed genes (P,<,0.01) were selected by Student's t -test. These genes appear biologically relevant, of 71 well-annotated genes from these 125 genes, 62 were overrepresented in five biochemical pathway networks (most linked to cancer), and all of these networks were linked by one gene, c - myc. Gene expression profiling at early time points accurately predicts NGTC potential of compounds, and the same data can be mined effectively for other toxicity signatures. Predictive genes confirm prior work and suggest pathways critical for early stages of carcinogenesis. © 2006 Wiley-Liss, Inc. [source] | |||||||||||||