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Reliable Approach (reliable + approach)
Selected AbstractsPredicting global abundance of a threatened species from its occurrence: implications for conservation planningDIVERSITY AND DISTRIBUTIONS, Issue 1 2009Marcos S. L. Figueiredo Abstract Aim, Global abundance is an important characteristic of a species that is correlated with geographical distribution and body size. Despite its importance these estimates are not available since reliable field estimates are either expensive or difficult to obtain. Based on the relationship between a species' local abundance and distribution, some authors propose that abundance can be obtained through spatial distribution data from maps plotted at different scales. This has never been tested over the entire geographical range of a species. Thus, the aim of this study was to estimate global abundance of the Neotropical primate Brachyteles hypoxanthus (northern muriqui) and compare the results with available field estimates. Location, From southern Bahia to Minas Gerais and Espírito Santo states, in the Brazilian Atlantic rain forest. Methods, We compiled 25 recent occurrence localities of B. hypoxanthus and plotted them in grid cells of five different sizes (1, 25, 50, 75 and 100 km per side) to evaluate the performance and accuracy of abundance estimates over a wide range of scales. The abundance estimates were obtained by the negative binomial distribution (NBD) method and corrected by average group size to take into account primate social habits. To assess the accuracy of the method, the predicted abundances were then compared to recent independent field estimates. Results, The NBD estimates were quite accurate in predicting B. hypoxanthus global abundance, once the gregarious habits of this species are taken into account. The predicted abundance estimates were not statistically different from those obtained from field estimates. Main conclusions, The NBD method seems to be a quick and reliable approach to estimate species abundance once several limiting factors are taken into account, and can greatly impact conservation planning, but further applications in macroecological and ecological theory testing needs improvement of the method. [source] Combined measurements of egg fatty acids and stable isotopes as indicators of feeding ecology in lake-dwelling birdsFRESHWATER BIOLOGY, Issue 9 2009FRANCISCO RAMÍREZ Summary 1.,We examined whether egg fatty acid (FA) profiles and stable isotopes (SIA) could be used in a comparative way to infer the diet of two aquatic bird species with contrasting feeding habits: a surface forager, the pheasant-tailed jacana (Hydrophasianus chirurgus), and a pursuit-diving forager, the little cormorant (Phalacrocorax niger), at Haleji Lake (Pakistan). 2.,The species differed markedly in the overall percentage of saturated and polyunsaturated fatty acids. Moreover, among jacanas, two groups of birds had relatively high or low concentrations of long-chain essential PUFAs (such as 18:2 n-6 and 20:4 n-6), suggesting differing contributions from animal prey and plant material. 3.,These trophic differences were corroborated by ,15N values which indicated both a higher trophic position in cormorants relative to jacanas, and differences in trophic position for the two groups of jacanas. In this latter species ,13C values in both groups also pointed to differing diets, involving mainly grazing plants or a contribution from animal resources (aquatic invertebrates or insects). 4.,Both lower values of ,13C and higher percentages of 18:1 n-7 detected in little cormorants may indicate the influence of the anoxic water, typical of a freshwater system densely covered by macrophytes. 5.,These results indicate how both biomarkers offer complementary information in studies of feeding ecology, refining interpretations of trophic pathways which are usually based on FA or SIA alone. Comparisons of FA profiles and SIA among species also proved to be a reliable approach for inferring the diet of species for which information is scarce or contradictory, as is the case for the pheasant-tailed jacana. [source] Fault diagnosis of a simulated industrial gas turbine via identification approachINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 4 2007S. Simani Abstract In this paper, a model-based procedure exploiting the analytical redundancy principle for the detection and isolation of faults on a simulated process is presented. The main point of the work consists of using an identification scheme in connection with dynamic observer and Kalman filter designs for diagnostic purpose. The errors-in-variables identification technique and output estimation approach for residual generation are in particular advantageous in terms of solution complexity and performance achievement. The proposed tools are analysed and tested on a single-shaft industrial gas turbine MATLAB/SIMULINK® simulator in the presence of disturbances, i.e. measurement errors and modelling mismatch. Selected performance criteria are used together with Monte-Carlo simulations for robustness and performance evaluation. The suggested technique can constitute the design methodology realising a reliable approach for real application of industrial process FDI. Copyright © 2006 John Wiley & Sons, Ltd. [source] Application of failure mode and effect analysis and cause and effect analysis and Pareto diagram in conjunction with HACCP to a chocolate-producing industry: a case study of tentative GMO detection at pilot plant scaleINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 11 2007Ioannis S. Arvanitoyannis Abstract Although the application of hazard analysis critical control point in the food industry dates back to the 1970s, a more quantitative and reliable approach towards risk assessment became feasible through application of failure mode and effect analysis (FMEA) model. A tentative approach of FMEA application to a filled chocolate-producing industry was attempted in an effort to exclude the presence of genetically modified organisms (GMOs) in the final product. This is of crucial importance both from the moral (ethics) and the legislation (EC 1829/2003; EC 1830/2003; EC 18/2001) point of view. Two structured methods (preliminary hazard analysis and fault tree analysis) were used to analyse and predict the occurring failure modes in food chain system, based on the functions, characteristics and/or interactions of the ingredients or the processes, upon which the system depends. Cause and effect diagram (also known as Ishikawa, tree diagram and fishbone diagram) and Pareto diagram emerged as two very useful and effective tools towards optimising the GMO detection potential of FMEA. [source] Assessment of potential approaches to improve Eucalyptus globulus kraft pulping yieldJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2007A. S. Santiago Abstract The main goal of this work is to study the potential approaches to improve polysaccharides retention during Eucalyptus globulus kraft pulping. The addition of anthraquinone to kraft pulping leads to the highest pulp yield while the addition of urea promotes lower depolymerization of polysaccharides (higher pulp viscosity), but does not have a significant effect on yield. The early interruption of kraft cooking followed by oxygen delignification is a reliable approach to increase pulp yield, particularly when pulping is interrupted at the end of the faster and more selective kinetic regime (bulk phase). Yield loss during oxygen delignification is considerably lower than that incurred in the last phase of kraft pulping. Pulping with OH,/HS, charge profiling, carried out with liquor injection in three different phases leads to a yield increase. However, this increase results from a lower total alkali charge applied when profiling pulping is compared to standard pulping conditions, rather than to alkali profiling. Standard kraft pulping with different active alkali (AA) charges demonstrated that this operational variable is determinant for pulp yield and viscosity. Pulping experiences with lower AA (14%) resulted in a higher and almost constant pulp viscosity and in a higher pulp yield, assigned to improved retention of both cellulose and xylan. During the last stage of pulping, cellulose content decreases, this being mainly responsible for the decrease of pulp yield, while xylan content is almost constant, a feature attributed to the peculiar structure of this E. globulus's hemicellulose. Copyright © 2007 Society of Chemical Industry [source] Assessment of theoretical methods for the calculation of methyl cation affinitiesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 2 2008Y. Wei Abstract The methyl cation affinity (MCA; 298 K) of a variety of neutral and anionic bases has been examined computationally with a wide variety of theoretical methods. These include high-level composite procedures such as W1, G3, G3B3, and G2, conventional ab initio methods such as CCSD(T) and MP2, as well as a selection of density functional theory (DFT) methods. Experimental results for a variety of small model systems are well reproduced with practically all these methods, and the performance of DFT based methods are far superior in comparison to their MP2 analogs for these small models. For larger model, systems including motifs frequently encountered in organocatalysts, the performance deteriorates somewhat for DFT methods, while it improves significantly for MP2, rendering the former methods unreliable for common organic bases. Thus, MP2 calculations performed in combination with basis sets such as 6-31+G(2d, p) or larger, appear to offer a practical and reliable approach to compute MCAs of organic bases. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008 [source] Experimental annotation of channel catfish virus by probabilistic proteogenomic mappingPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 10 2009Dusan Kunec Dr. Abstract Experimental identification of expressed proteins by proteomics constitutes the most reliable approach to identify genomic location and structure of protein-coding genes and substantially complements computational genome annotation. Channel catfish herpesvirus (CCV) is a simple comparative model for understanding herpesvirus biology and the evolution of the Herpesviridae. The canonical CCV genome has 76 predicted ORF and only 12 of these have been confirmed experimentally. We describe a modification of a statistical method, which assigns significance measures, q -values, to peptide identifications based on 2-D LC ESI MS/MS, real-decoy database searches and SEQUEST XCorr and ,Cn scores. We used this approach to identify CCV proteins expressed during its replication in cell culture, to determine protein composition of mature virions and, consequently, to refine the canonical CCV genome annotation. To complement trypsin, we used partial proteinase K digestion, which yielded greater proteome coverage. At FDR <5%, for peptide identifications, we identified 25/76 previously predicted ORF using trypsin and 31/76 using proteinase K. Furthermore, we identified 17 novel protein-coding regions (7 potential ATG-initiated ORF). Most of these novel ORF encode small proteins (<100 amino acids). Directed, strand-specific reverse transcription real-time PCR confirmed RNA expression from 6/7 novel ATG-initiated ORF investigated. [source] Identification of the proteins present in the bull sperm cytosolic fraction enriched in tyrosine kinase activity: A proteomic approachPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 16 2006Claudia Lalancette Abstract Numerous sperm proteins have been identified on the basis of their increase in tyrosine phosphorylation during capacitation. However, the tyrosine kinases present in spermatozoa that are responsible for this phosphorylation remain unknown. As spermatozoa are devoid of transcriptional and translational activities, molecular biology approaches might not reflect the transcriptional pattern in mature spermatozoa. Working directly with the proteins present in ejaculated spermatozoa is the most reliable approach to identify the tyrosine kinases potentially involved in the capacitation-associated increase in protein tyrosine phosphorylation. A combination of tyrosine kinase assays and proteomic identification tools were used as an approach to identify sperm protein tyrosine kinases. Fractionation by nitrogen cavitation showed that the majority of tyrosine kinase activity is present in the cytosolic fraction of bovine spermatozoa. By the use of Poly-Glu:Tyr(4:1)-agarose affinity chromatography, we isolated a fraction enriched in tyrosine kinase activity. Proteomics approaches permitted the identification of tyrosine kinases from three families: Src (Lyn), Csk, and Tec (Bmx, Btk). We also identified proteins implicated in different cellular events associated with sperm capacitation and acrosome reaction. These results confirm the implication of tyrosine phosphorylation in some aspects of capacitation/acrosome reaction and reveal the identity of new players potentially involved in these processes. [source] Generalized confidence intervals for assessing process capability of multiple production linesQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 6 2009Chien-Wei Wu Abstract Process capability indices (PCIs) have become popular as unit-less measures on whether a process is capable of reproducing items meeting the quality requirement. A reliable approach for testing process capability is to establish an interval estimate, for which we can assert that it contains the true PCI value with a reasonable degree of certainty. However, the construction of such an interval estimate is not trivial, since the distribution of the commonly used Cpk index involves unknown parameters. In this paper, we adopt the concept of generalized confidence intervals and generalized pivotal quantities to derive the generalized lower confidence bounds for providing critical information on process performance. Two practical applications in the area of process capability were considered, they include (i) assessing whether a process under investigation is capable and (ii) providing the lowest performance of the manufacturing processes from several production lines or several suppliers for quality assurance. The applicability of the derived results is also illustrated with examples. Copyright © 2008 John Wiley & Sons, Ltd. [source] Can density functional theory (DFT) be used as an aid to a deeper understanding of tandem mass spectrometric fragmentation pathways?RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 17 2009Alexander Alex Prediction of tandem mass spectrometric (MS/MS) fragmentation for non-peptidic molecules based on structure is of immense interest to the mass spectrometrist. If a reliable approach to MS/MS prediction could be achieved its impact within the pharmaceutical industry could be immense. Many publications have stressed that the fragmentation of a molecular ion or protonated molecule is a complex process that depends on many parameters, making prediction difficult. Commercial prediction software relies on a collection of general heuristic rules of fragmentation, which involve cleaving every bond in the structure to produce a list of ,expected' masses which can be compared with the experimental data. These approaches do not take into account the thermodynamic or molecular orbital effects that impact on the molecule at the point of protonation which could influence the potential sites of bond cleavage based on the structural motif. A series of compounds have been studied by examining the experimentally derived high-resolution MS/MS data and comparing it with the in silico modelling of the neutral and protonated structures. The effect that protonation at specific sites can have on the bond lengths has also been determined. We have calculated the thermodynamically most stable protonated species and have observed how that information can help predict the cleavage site for that ion. The data have shown that this use of in silico techniques could be a possible way to predict MS/MS spectra. Copyright © 2009 John Wiley & Sons, Ltd. [source] Accuracy of preoperative ultrasound and ultrasound-guided fine needle aspiration cytology for axillary staging in breast cancerANZ JOURNAL OF SURGERY, Issue 4 2010Jinhyang Jung Abstract Background:, The aims of this study were to evaluate the accuracy of preoperative ultrasound and ultrasound-guided fine needle aspiration (FNA) cytology (US-FNAC) for detecting axillary metastases, and to assess how often sentinel node biopsy could be avoided. Methods:, Axillary ultrasound, as a part of routine preoperative staging, was performed in 189 patients with histologically proven breast cancer. US-FNAC was performed on all lymph nodes (LNs) with features suggestive of metastatic disease on ultrasound characteristics and LNs larger than 1 cm regardless of whether the nodes appear normal or abnormal. The cytologic results were compared with the final histological diagnosis. Results:, The sensitivity, specificity and positive and negative predictive values of the ultrasound alone of axillary LNs for metastatic breast cancer were 54, 91, 75 and 81%, retrospectively. For the US-FNAC, the respective values were 80, 98, 97 and 84%. Conclusions:, Preoperative axillary ultrasound in combination with US-FNAC provides a simple, minimally invasive and reliable approach to the initial determination of the axillary LN status. Those who are US-FNAC positive can be referred for axillary LN dissection without sentinel LN biopsy. [source] A critical analysis of the role of gut Oxalobacter formigenes in oxalate stone diseaseBJU INTERNATIONAL, Issue 1 2009Siddharth Siva Hyperoxaluria is a major risk factor for the formation of calcium oxalate stones, but dietary restriction of oxalate intake might not be a reliable approach to prevent recurrence of stones. Hence, other approaches to reduce urinary oxalate to manage stone disease have been explored. The gut-dwelling obligate anaerobe Oxalobacter formigenes (OF) has attracted attention for its oxalate-degrading property. In this review we critically evaluate published studies and identify major gaps in knowledge. Recurrent stone-formers are significantly less likely to be colonized with OF than controls, but this appears to be due to antibiotic use. Studies in animals and human subjects show that colonization of the gut with OF can decrease urinary oxalate levels. However, it remains to be determined whether colonization with OF can affect stone disease. Reliable methods are needed to detect and quantify colonization status and to achieve durable colonization. New information about oxalate transport mechanisms raises hope for pharmacological manipulation to decrease urinary oxalate levels. In addition, probiotic use of lactic acid bacteria that metabolize oxalate might provide a valid alternative to OF. [source] | |||||||||||||||||||