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Identification Techniques (identification + techniques)
Selected AbstractsIdentification of Acipenseriformes species in tradeJOURNAL OF APPLIED ICHTHYOLOGY, Issue 2008A. Ludwig Summary Sturgeons and paddlefishes (Acipenseridae) are highly endangered freshwater fishes. Their eggs (sold as caviar) are one of the most valuable wildlife products in international trade. Concerns of overharvesting and the conservation status of many of the 27 extant species of Acipenseriformes led to all species being included on the CITES Appendices in 1998. Since then international trade in all products and parts from sturgeon and paddlefish has been regulated. However, despite the controls on trade, unsustainable harvesting continues to threaten many populations. Illegal fishing and trade continues to be a threat to the management of these fish. To enforce the regulation of legal trade and prevention of illegal trade, the development of a uniform identification system for parts and derivates of Acipenseriformes has been identified as an urgent requirement. Ideally this system should be suitable for (i) identification at the species-level of caviar and other products from Acipenseriformes; (ii) population identification; (iii) source identification (wild vs aquaculture); and (iv) determining the age of caviar because strict timeframes govern its international trade. This paper reviews the techniques currently available and their potential to be used in an identification system for Acipenseriformes species and their products in trade. A review of all available identification techniques has shown that there is not a single method that can meet all requirements (see i,iv), and it does not appear to be feasible to develop such a method in the near future therefore the most appropriate methods need to be developed for each. Considering the advantages and disadvantages of all techniques reviewed in this document, the following conclusions can be drawn: (i) for the identification of species, approaches are recommended that target mitochondrial cytochrome b sequences (RFLP, nested PCR or direct sequencing). However, they show limitations for the detection of hybrids (although natural hybrids are rare, the number of artificially produced hybrids in aquaculture is increasing) and for the differentiation of the following closely related species complexes: Acipenser gueldenstaedti,Acipenser baerii,Acipenser persicus,Acipenser naccarii; Acipenser medirostris,Acipenser mikadoi; and Scaphirhynchus albus,Scaphirhynchus plathorhynchus,Scaphirhynchus suttkusi; (ii) the identification of different populations of the same species is currently not feasible because genetic data are incomplete for most populations, and stocking and release programmes, which have become more and more common, often result in a mixture of phenotypes and genotypes, thereby impeding the creation and application of such a population identification system; (iii) source identification based on genetic approaches can be excluded at present because there are no genetic differences between wild and hatchery-raised fish. This is the result of the continuing restocking of natural populations with captive fish and vice versa. However, because rearing (i.e. environmental) conditions are different, methods focusing on differences in water quality or food seem to be more appropriate (for example differences in fatty acid composition). So far, very few studies have been conducted and therefore, source identification methods merit further exploration; and (iv) the age of a product in trade cannot be detected by DNA-based methods and protein profiling is undoubtedly impractical due to hard-to-perform, labour-and cost-intensive methods, which are highly susceptible to protein degradation. Arising from the limits discussed above, the next steps in the development of a uniform sturgeon identification system are proposed to be the following: (i) designation of qualified reference laboratories at national levels in (re-) exporting and importing countries. These should be approved through a standardized testing procedure, for instance a ring test on blind samples. Registered laboratories should be published and disseminated and their accreditations should be subject to certain guarantees regarding quality, economic independence and scientific rigour. Operational procedures have to be determined and standardized among reference laboratories; (ii) establishment of reference collections that are accessible to the reference laboratories containing DNA analyses results and information on the location and availability of tissue samples. This is highly recommended as an important step towards a population identification system and indispensable for a general species identification system; (iii) creation of a website access to the reference collections containing the reference database information about genetic samples, comparable to NCBI, which provides background data: sample location; population information; citation; available genetic data; location of archival storage; currently treated and distributed caviar and status of analysis. This website should also be a forum for the exchange of knowledge on and experiences with identification systems, species and population status information, relevant scientific research, etc.; and (iv) the outcome of the trade identification tests should be made available to the reference laboratories for future reference. The universal caviar labelling system could incorporate an indication of the verification of the consignment. In view of the lack of knowledge and the great need to develop a uniform identification system for Acipenseriformes with regard to the importance of the international caviar trade, further scientific guidance and appropriate research is strongly recommended. Progress should be assessed and exchanged on a regular basis. [source] Phenotypic and genotypic characterization of competitive exclusion products for use in poultryJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2003R.D. Wagner Abstract Aims: Phenotypic and genotypic bacteria identification methods were compared for their efficacy in determining the composition of competitive exclusion (CE) products. Methods and Results: Phenotypic methods used for bacterial identification were fatty acid methyl ester profiles, biochemical assays and carbohydrate utilization profiles. Genotypic methods were MicroSeq16S rRNA sequence analysis and BLAST searches of the GenBank sequence database. Agreement between phenotypic and genotypic methods for identification of bacteria isolated from the Preempt CE product was 20%. A defined test mixture of bacteria was identified to the species level 100% by BLAST analysis, 64% by MicroSeq and 36% by phenotypic techniques. Conclusions: The wide range of facultative and obligate anaerobic bacteria present in a CE product are more accurately identified with 16S rRNA sequence analyses than with phenotypic identification techniques. Significance and Impact of the Study: These results will provide guidelines for manufacturers of CE products to submit more reliable product information for market approval by regulatory agencies. [source] A new framework for data reconciliation and measurement bias identification in generalized linear dynamic systemsAICHE JOURNAL, Issue 7 2010Hua Xu Abstract This article describes a new framework for data reconciliation in generalized linear dynamic systems, in which the well-known Kalman filter (KF) is inadequate for filtering. In contrast to the classical formulation, the proposed framework is in a more concise form but still remains the same filtering accuracy. This comes from the properties of linear dynamic systems and the features of the linear equality constrained least squares solution. Meanwhile, the statistical properties of the framework offer new potentials for dynamic measurement bias detection and identification techniques. On the basis of this new framework, a filtering formula is rederived directly and the generalized likelihood ratio method is modified for generalized linear dynamic systems. Simulation studies of a material network present the effects of both the techniques and emphatically demonstrate the characteristics of the identification approach. Moreover, the new framework provides some insights about the connections between linear dynamic data reconciliation, linear steady state data reconciliation, and KF. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Individualized and time-variant model for the functional link between thermoregulation and sleep onsetJOURNAL OF SLEEP RESEARCH, Issue 2 2006STIJN QUANTEN Summary This study makes use of control system model identification techniques to examine the relationship between thermoregulation and sleep regulation. Specifically, data-based mechanistic (DBM) modelling is used to formulate and experimentally test the hypothesis, put forth by Gilbert et al. [Sleep Med. Rev.8 (2004) 81], that there exists a connection between distal heat loss and sleepiness. Six healthy sleepers each spent three nights and the following day in the sleep laboratory: an adaptation, a cognitive arousal and a neutral testing day. In the cognitive arousal condition, a visit of a television camera crew took place and subjects were asked to be interviewed. During each of the three 25-min driving simulator tasks per day, the distal-to-proximal gradient and the electroencephalogram are recorded. It is observed from these experimental data that there exists a feedback connection between thermoregulation and sleep. In addition to providing experimental evidence in support of the Gilbert et al. (2004) hypothesis, the authors propose that the nature of the feedback connection is determined by the nature of sleep/wake state (i.e. NREM sleep versus unwanted sleepiness in active subjects). Besides this, an individualized and time-variant model for the linkage between thermoregulation and sleep onset is presented. This compact model feeds on real-time data regarding distal heat loss and sleepiness and contains a physically meaningful parameter that delivers an individual- and time-depending quantification of a well known biological features in the field of thermoregulation: the thermoregulatory error signal Thypo(t),Tset(t). A validation of these physical/biological features emphasizes the reliability and power of DBM in describing individual differences related to the sleep process. [source] ABUNDANCE OF BOTTLENOSE DOLPHINS IN THE BAYS, SOUNDS, AND ESTUARIES OF NORTH CAROLINAMARINE MAMMAL SCIENCE, Issue 1 2003Andrew J. Read We conducted a mark-recapture survey of bottlenose dolphins Tursiops truncatus in the bays, sounds, and estuaries of North Carolina during July 2000, using photographic identification techniques. During this survey we took 7,682 photographs of dolphins and, of these, 3,457 images were of sufficient quality for analysis. We identified 306 dolphins from distinctive nicks and notches on their dorsal fins. Eighry-six dolphins were photographed on more than one occasion during the course of the survey; one dolphin was photographed on four separate days. We then applied the results of our photographic analyses to several mark-recapture models and examined potential violations of the assumptions of these models, including an unexpected correlation between photo quality and mark distinctiveness. Our analysis suggests that our results are robusr to possible violations of these assumptions. The resulting estimates were then scaled to account for the proportion (0.46) of unmarked dolphins in the population. Our best estimate of the number of dolphins present in the inshore waters of North Carolina during July 2000 is 1,033 with a 95% Confidence Interval of 860,1,266 (CV = 0.099). Most dolphins were found in the northern part of the study area, which includes the second largest estuarine system in the United States. [source] Use of checkerboard DNA,DNA hybridization to study complex microbial ecosystemsMOLECULAR ORAL MICROBIOLOGY, Issue 6 2004S. S. Socransky It has been difficult to conduct large scale studies of microbiologically complex ecosystems using conventional microbiological techniques. Molecular identification techniques in new probe-target formats, such as checkerboard DNA,DNA hybridization, permit enumeration of large numbers of species in very large numbers of samples. Digoxigenin-labeled whole genomic probes to 40 common subgingival species were tested in a checkerboard hydridization format. Chemifluorescent signals resulting from the hybridization reactions were quantified using a Fluorimager and used to evaluate sensitivity and specificity of the probes. Sensitivity of the DNA probes was adjusted to detect 104 cells. In all, 93.5% of potential cross-reactions to 80 cultivable species exhibited signals <5% of that detected for the homologous probe signal. Competitive hybridization and probes prepared by subtraction hybridization and polymerase chain reaction were effective in minimizing cross-reactions for closely related taxa. To demonstrate utility, the technique was used to evaluate 8887 subgingival plaque samples from 79 periodontally healthy and 272 chronic periodontitis subjects and 8126 samples from 166 subjects taken prior to and after periodontal therapy. Significant differences were detected for many taxa for mean counts, proportion of total sample, and percentage of sites colonized between samples from periodontally healthy and periodontitis subjects. Further, significant reductions were observed post therapy for many subgingival species including periodontal pathogens. DNA probes used in the checkerboard DNA,DNA format provide a useful tool for the enumeration of bacterial species in microbiologically complex systems. [source] Identification and fine tuning of closed-loop processes under discrete EWMA and PI adjustmentsQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 6 2001Rong Pan Abstract Conventional process identification techniques of a open-loop process use the cross-correlation function between historical values of the process input and of the process output. If the process is operated under a linear feedback controller, however, the cross-correlation function has no information on the process transfer function because of the linear dependency of the process input on the output. In this paper, several circumstances where a closed-loop system can be identified by the autocorrelation function of the output are discussed. It is assumed that a proportional integral controller with known parameters is acting on the process while the output data were collected. The disturbance is assumed to be a member of a simple yet useful family of stochastic models, which is able to represent drift. It is shown that, with these general assumptions, it is possible to identify some dynamic process models commonly encountered in manufacturing. After identification, our approach suggests to tune the controller to a near-optimal setting according to a well-known performance criterion. Copyright © 2001 John Wiley & Sons, Ltd. [source] Biases associated with population estimation using molecular taggingANIMAL CONSERVATION, Issue 3 2000Juliann L. Waits Although capture,recapture techniques are often used to estimate population size, these approaches are difficult to implement for a wide variety of species. Highly polymorphic microsatellite markers are useful in individual identification, and these ,molecular tags' can be collected without having to capture or trap the individual. However, several sources of error associated with molecular identification techniques, including failure to identify individuals with the same genotype for these markers as being different, and incorrect assignment of individual genotypes, could bias population estimates. Simulations of populations sampled for the purpose of estimating population size were used to assess the extent of these potential biases. Population estimates tended to be biased downward as the likelihood of individuals sharing the same genotype increased (as measured by the probability of identity (PI) of the multi-locus genotype); this bias increased with population size. Populations of 1000 individuals were underestimated by ,5% when the PI was as small as 1.4 × 10,7. A similar-sized bias did not occur for populations of 50 individuals until the PI had increased to approximately 2.5 × 10,5. Errors in genotype assignment resulted in overestimates of population size; this problem increased with the number of samples and loci that were genotyped. Population estimates were often >200% the size of the simulated populations when the probability of making a genotyping error was 0.05/locus and 7,10 loci were used to identify individuals. This bias was substantially reduced by decreasing genotyping error rate to 0.005. If possible, only highly polymorphic loci that are critical for the identification of the individual should be used in molecular tagging, and considerable efforts should be made to minimize errors in genotype determination. [source] Identification based adaptive iterative learning controllerASIAN JOURNAL OF CONTROL, Issue 5 2010Suhail Ashraf Abstract In recent years, more research in the control field has been in the area of self-learning and adaptable systems, such as a robot that can teach itself to improve its performance. One of the more promising algorithms for self-learning control systems is Iterative Learning Control (ILC), which is an algorithm capable of tracking a desired trajectory within a specified error limit. Conventional ILC algorithms have the problem of relatively slow convergence rate and adaptability. This paper suggests a novel approach by combining system identification techniques with the proposed ILC approach to overcome the aforementioned problems. The ensuing design procedure is explained and results are accrued from a number of simulation examples. A key point in the proposed scheme is the computation of gain matrices using the steepest descent approach. It has been found that the learning rule can be guaranteed to converge if certain conditions are satisfied. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] | ||||||||||||||||