WorldWideScience

Sample records for chain rotamer sampling

  1. A protein-dependent side-chain rotamer library.

    KAUST Repository

    Bhuyan, M.S.

    2011-12-14

    Protein side-chain packing problem has remained one of the key open problems in bioinformatics. The three main components of protein side-chain prediction methods are a rotamer library, an energy function and a search algorithm. Rotamer libraries summarize the existing knowledge of the experimentally determined structures quantitatively. Depending on how much contextual information is encoded, there are backbone-independent rotamer libraries and backbone-dependent rotamer libraries. Backbone-independent libraries only encode sequential information, whereas backbone-dependent libraries encode both sequential and locally structural information. However, side-chain conformations are determined by spatially local information, rather than sequentially local information. Since in the side-chain prediction problem, the backbone structure is given, spatially local information should ideally be encoded into the rotamer libraries. In this paper, we propose a new type of backbone-dependent rotamer library, which encodes structural information of all the spatially neighboring residues. We call it protein-dependent rotamer libraries. Given any rotamer library and a protein backbone structure, we first model the protein structure as a Markov random field. Then the marginal distributions are estimated by the inference algorithms, without doing global optimization or search. The rotamers from the given library are then re-ranked and associated with the updated probabilities. Experimental results demonstrate that the proposed protein-dependent libraries significantly outperform the widely used backbone-dependent libraries in terms of the side-chain prediction accuracy and the rotamer ranking ability. Furthermore, without global optimization/search, the side-chain prediction power of the protein-dependent library is still comparable to the global-search-based side-chain prediction methods.

  2. SDRL: a sequence-dependent protein side-chain rotamer library.

    Science.gov (United States)

    Taghizadeh, Mohammad; Goliaei, Bahram; Madadkar-Sobhani, Armin

    2015-07-01

    Since the introduction of the first protein side-chain rotamer library (RL) almost half a century ago, RLs have been components of many programs and algorithms in structural bioinformatics. Based on the dependence of side-chain dihedral angles on the local backbone, three types of RLs have been identified: backbone-independent, secondary-structure-dependent and backbone-dependent. In all previous studies, the effect of sequence specificity on side-chain conformational preferences was neglected. In the effort to develop a new class of RLs, we considered that the side-chain conformation of the central residue in each triplet on a protein backbone depends on the sequence of the triplet; therefore, we developed a sequence-dependent rotamer library (SDRL). To accomplish this, 400 possible triplet sequences for 18 natural amino acids as the central residue, which corresponds to 7200 triplet sequences in total, were considered. Searching the set of 11 546 selected PDB entries for the 7200 triplet sequences resulted in 2 364 541 instances occurring for 18 amino acids. Our results show that Leu and Val experience minimal impact from the adjacent residues in adopting side-chain conformations. Cys, Ile, Trp, His, Asp, Met, Glu, Gln, Arg and Lys, on the other hand, adopt their side-chain conformations mostly based on the adjacent residues on the backbone. The remaining residue types were moderately dependent on the adjacent residues. Using the new library, side-chain repacking algorithms can find preferred conformations of each residue more easily than with other backbone-independent RLs. PMID:25953624

  3. Beyond rotamers: a generative, probabilistic model of side chains in proteins

    DEFF Research Database (Denmark)

    Harder, Tim; Boomsma, Wouter; Paluszewski, Martin; Frellsen, Jes; Johansson, Kristoffer Enøe; Hamelryck, Thomas

    2010-01-01

    collections of side chain conformations derived from experimentally determined protein structures. The discretization can be exploited to efficiently search the conformational space. However, discretizing this naturally continuous space comes at the cost of losing detailed information that is crucial for...

  4. The interplay between transient a-helix formation and side chain rotamer distributions in disordered proteins probed by methyl chemical shifts

    DEFF Research Database (Denmark)

    Kjærgaard, Magnus; Iesmantavicius, Vytautas; Poulsen, Flemming M

    2011-01-01

    shifts can in principle report the conformations of aliphatic side chains in disordered proteins and in order to examine this two model systems were chosen: the acid denatured state of acyl-CoA binding protein (ACBP) and the intrinsically disordered activation domain of the activator for thyroid hormone...... allow a quantitative analysis of the ensemble of ¿(2)-angles of especially leucine residues in disordered proteins. The changes in the rotamer distributions upon denaturation correlate to the changes upon helix induction by the co-solvent trifluoroethanol, suggesting that the side chain conformers are......The peptide backbones of disordered proteins are routinely characterized by NMR with respect to transient structure and dynamics. Little experimental information is, however, available about the side chain conformations and how structure in the backbone affects the side chains. Methyl chemical...

  5. Rapid flexible docking using a stochastic rotamer library of ligands

    OpenAIRE

    Ding, Feng; Yin, Shuangye; Dokholyan, Nikolay V.

    2010-01-01

    Existing flexible docking approaches model the ligand and receptor flexibility either separately or in a loosely-coupled manner, which captures the conformational changes inefficiently. Here, we propose a flexible docking approach, MedusaDock, which models both ligand and receptor flexibility simultaneously with sets of discrete rotamers. We develop an algorithm to build the ligand rotamer library “on-the-fly” during docking simulations. MedusaDock benchmarks demonstrate a rapid sampling effi...

  6. Correlation of tryptophan fluorescence intensity decay parameters with sup 1 H NMR-determined rotamer conformations: (tryptophan sup 2 )oxytocin

    Energy Technology Data Exchange (ETDEWEB)

    Ross, J.B.A.; Schwartz, G.P.; Laws, W.R. (Mount Sinai, New York, NY (United States)); Wyssbrod, H.R.; Porter, R.A. (Univ. of Louisville, KY (United States)); Michaels, C.A. (Swarthmore Coll., PA (United States))

    1992-02-18

    While the fluorescence decay kinetics of tyrosine model compounds can be explained in terms of heterogeneity derived from the three ground-state {chi}{sup 1} rotamers, a similar correlation has yet to be directly observed for a tryptophan residue. In addition, the asymmetric indole ring might also lead to heterogeneity from {chi}{sup 2} rotations. In this paper, the time-resolved and steady-state fluorescence properties of (tryptophan{sup 2})oxytocin at pH 3 are presented and compared with {sup 1}H NMR results. According to the unrestricted analyses of individual fluorescence decay curves taken as a function of emission wavelength-independent decay constants, only three exponential terms are required. In addition, the preexponential weighting factors (amplitudes) have the same relative relationship (weights) as the {sup 1}H NMR-determined {chi}{sup 1} rotamer populations of the indole side chain. {sup 15}N was used in heteronuclear coupling experiments to confirm the rotamer assignments. Inclusion of a linked function restricting the decay amplitudes to the {chi}{sup 1} rotamer populations in the individual decay curve analyses and in the global analysis confirms this correlation. According to qualitative nuclear Overhauser data, there are two {chi}{sup 2} populations.

  7. CLTs and asymptotic variance of time-sampled Markov chains

    CERN Document Server

    Latuszynski, Krzysztof

    2011-01-01

    For a Markov transition kernel $P$ and a probability distribution $ \\mu$ on nonnegative integers, a time-sampled Markov chain evolves according to the transition kernel $P_{\\mu} = \\sum_k \\mu(k)P^k.$ In this note we obtain CLT conditions for time-sampled Markov chains and derive a spectral formula for the asymptotic variance. Using these results we compare efficiency of Barker's and Metropolis algorithms in terms of asymptotic variance.

  8. Limit Theorems for the Sample Entropy of Hidden Markov Chains

    CERN Document Server

    Han, Guangyue

    2011-01-01

    The Shannon-McMillan-Breiman theorem asserts that the sample entropy of a stationary and ergodic stochastic process converges to the entropy rate of the same process almost surely. In this paper, we focus our attention on the convergence behavior of the sample entropy of a hidden Markov chain. Under certain positivity assumption, we prove that a central limit theorem (CLT) with some Berry-Esseen bound for the sample entropy of a hidden Markov chain, and we use this CLT to establish a law of iterated logarithm (LIL) for the sample entropy.

  9. Cis–Trans Amide Bond Rotamers in β-Peptoids and Peptoids: Evaluation of Stereoelectronic

    DEFF Research Database (Denmark)

    Laursen, Jonas Striegler; Engel-Andreasen, Jens; Fristrup, Peter; Harris, Pernille; Olsen, Christian Adam

    2013-01-01

    folding propensity. Thus, we here report an investigation of the effect of structural variations on the cis–trans amide bond rotamer equilibria in a selection of monomer model systems. In addition to various side chain effects, which correlated well with previous studies of α-peptoids, we present the...... synthesis and investigation of cis–trans isomerism in the first examples of peptoids and β-peptoids containing thioamide bonds as well as trifluoroacetylated peptoids and β-peptoids. These systems revealed an increase in the preference for cis-amides as compared to their parent compounds, and thus provide...

  10. Two-stage chain sampling inspection plans with different sample sizes in the two stages

    Science.gov (United States)

    Stephens, K. S.; Dodge, H. F.

    1976-01-01

    A further generalization of the family of 'two-stage' chain sampling inspection plans is developed - viz, the use of different sample sizes in the two stages. Evaluation of the operating characteristics is accomplished by the Markov chain approach of the earlier work, modified to account for the different sample sizes. Markov chains for a number of plans are illustrated and several algebraic solutions are developed. Since these plans involve a variable amount of sampling, an evaluation of the average sampling number (ASN) is developed. A number of OC curves and ASN curves are presented. Some comparisons with plans having only one sample size are presented and indicate that improved discrimination is achieved by the two-sample-size plans.

  11. Organic cleanliness of the Mars Science Laboratory sample transfer chain.

    Science.gov (United States)

    Blakkolb, B; Logan, C; Jandura, L; Okon, A; Anderson, M; Katz, I; Aveni, G; Brown, K; Chung, S; Ferraro, N; Limonadi, D; Melko, J; Mennella, J; Yavrouian, A

    2014-07-01

    One of the primary science goals of the Mars Science Laboratory (MSL) Rover, Curiosity, is the detection of organics in Mars rock and regolith. To achieve this, the Curiosity rover includes a robotic sampling system that acquires rock and regolith samples and delivers it to the Sample Analysis at Mars (SAM) instrument on board the rover. In order to provide confidence that any significant organics detection result was Martian and not terrestrial in origin, a requirement was levied on the flight system (i.e., all sources minus the SAM instrument) to impart no more than 36 parts per billion (ppb by weight) of total reduced carbon terrestrial contamination to any sample transferred to the SAM instrument. This very clean level was achieved by a combination of a rigorous contamination control program on the project, and then using the first collected samples for a "dilution cleaning" campaign of the sample chain prior to delivering a sample to the SAM instrument. Direct cleanliness assays of the sample-contacting and other Flight System surfaces during pre-launch processing were used as inputs to determine the number of dilution cleaning samples needed once on Mars, to enable delivery of suitably clean samples to the SAM experiment. Taking into account contaminant redistribution during launch thorough landing of the MSL on Mars, the amount of residue present on the sampling hardware prior to the time of first dilution cleaning sample acquisition was estimated to be 60 ng/cm(2) on exposed outer surfaces of the sampling hardware and 20 ng/cm(2) on internal sample contacting surfaces; residues consisting mainly of aliphatic hydrocarbons and esters. After three dilution cleaning samples, estimated in-sample contamination level for the first regolith sample delivered to the SAM instrument at the Gale Crater "Rocknest" site was bounded at ≤10 ppb total organic carbon. A Project decision to forego ejecting the dilution cleaning sample and instead transfer the first drill

  12. Identification of new, well-populated amino-acid sidechain rotamers involving hydroxyl-hydrogen atoms and sulfhydryl-hydrogen atoms

    OpenAIRE

    Ho, Bosco K.; Agard, David A.

    2008-01-01

    Background An important element in homology modeling is the use of rotamers to parameterize the sidechain conformation. Despite the many libraries of sidechain rotamers that have been developed, a number of rotamers have been overlooked, due to the fact that they involve hydrogen atoms. Results We identify new, well-populated rotamers that involve the hydroxyl-hydrogen atoms of Ser, Thr and Tyr, and the sulfhydryl-hydrogen atom of Cys, using high-resolution crystal structures (

  13. Identification of new, well-populated amino-acid sidechain rotamers involving hydroxyl-hydrogen atoms and sulfhydryl-hydrogen atoms

    OpenAIRE

    Agard David A; Ho Bosco K

    2008-01-01

    Abstract Background An important element in homology modeling is the use of rotamers to parameterize the sidechain conformation. Despite the many libraries of sidechain rotamers that have been developed, a number of rotamers have been overlooked, due to the fact that they involve hydrogen atoms. Results We identify new, well-populated rotamers that involve the hydroxyl-hydrogen atoms of Ser, Thr and Tyr, and the sulfhydryl-hydrogen atom of Cys, using high-resolution crystal structures (

  14. Three sample preparation protocols for polymerase chain reaction based detection of Cryptosporidium parvum in environmental samples.

    Science.gov (United States)

    Kostrzynska, M; Sankey, M; Haack, E; Power, C; Aldom, J E; Chagla, A H; Unger, S; Palmateer, G; Lee, H; Trevors, J T; De Grandis, S A

    1999-02-01

    Cryptosporidium parvum is a protozoan parasite responsible for an increasing number of outbreaks of gastrointestinal illness worldwide. In this report, we describe development of sample preparation protocols for polymerase chain reaction (PCR)-based detection of C. parvum in fecal material and environmental water samples. Two of these methods were found adequate for isolation of Cryptosporidium DNA from filtered water pellet suspensions. The first involved several filtration steps, immunomagnetic separation and freeze-thaw cycles. The second method involved filtration, addition of EnviroAmp lysis reagent, freeze-thaw cycles and precipitation of the DNA with isopropanol. Using nested PCR, we detected 100 oocysts/ml of filtered water pellet suspension, with either of the above sample preparation procedures. Nested PCR increased sensitivity of the assay by two to three orders of magnitude as compared to the primary PCR. The detection limit for seeded fecal samples was 10-fold higher than for filtered environmental water pellet suspension. Nested PCR results showed 62.4 and 91.1% correlation with immunofluorescence assay (IFA) for fecal samples and filtered environmental water pellet suspensions, respectively. This correlation decreased to 47.2% and 44.4%, respectively, when only IFA positive samples were analyzed. However, in fecal samples contaminated with a high number (> 10(5)/g) of C. parvum oocysts, this correlation was 100%. PMID:10076632

  15. Ensemble bayesian model averaging using markov chain Monte Carlo sampling

    Energy Technology Data Exchange (ETDEWEB)

    Vrugt, Jasper A [Los Alamos National Laboratory; Diks, Cees G H [NON LANL; Clark, Martyn P [NON LANL

    2008-01-01

    Bayesian model averaging (BMA) has recently been proposed as a statistical method to calibrate forecast ensembles from numerical weather models. Successful implementation of BMA however, requires accurate estimates of the weights and variances of the individual competing models in the ensemble. In their seminal paper (Raftery etal. Mon Weather Rev 133: 1155-1174, 2(05)) has recommended the Expectation-Maximization (EM) algorithm for BMA model training, even though global convergence of this algorithm cannot be guaranteed. In this paper, we compare the performance of the EM algorithm and the recently developed Differential Evolution Adaptive Metropolis (DREAM) Markov Chain Monte Carlo (MCMC) algorithm for estimating the BMA weights and variances. Simulation experiments using 48-hour ensemble data of surface temperature and multi-model stream-flow forecasts show that both methods produce similar results, and that their performance is unaffected by the length of the training data set. However, MCMC simulation with DREAM is capable of efficiently handling a wide variety of BMA predictive distributions, and provides useful information about the uncertainty associated with the estimated BMA weights and variances.

  16. Economic Design of Acceptance Sampling Plans in a Two-Stage Supply Chain

    Directory of Open Access Journals (Sweden)

    Lie-Fern Hsu

    2012-01-01

    Full Text Available Supply Chain Management, which is concerned with material and information flows between facilities and the final customers, has been considered the most popular operations strategy for improving organizational competitiveness nowadays. With the advanced development of computer technology, it is getting easier to derive an acceptance sampling plan satisfying both the producer's and consumer's quality and risk requirements. However, all the available QC tables and computer software determine the sampling plan on a noneconomic basis. In this paper, we design an economic model to determine the optimal sampling plan in a two-stage supply chain that minimizes the producer's and the consumer's total quality cost while satisfying both the producer's and consumer's quality and risk requirements. Numerical examples show that the optimal sampling plan is quite sensitive to the producer's product quality. The product's inspection, internal failure, and postsale failure costs also have an effect on the optimal sampling plan.

  17. Adapting chain referral methods to sample new migrants: Possibilities and limitations

    Directory of Open Access Journals (Sweden)

    Lucinda Platt

    2015-09-01

    Full Text Available Background: Demographic research on migration requires representative samples of migrant populations. Yet recent immigrants, who are particularly informative about current migrant flows, are difficult to capture even in specialist surveys. Respondent-driven sampling (RDS, a chain referral sampling and analysis technique, potentially offers the opportunity to achieve population-level inference of recently arrived migrant populations. Objective: We evaluate the attempt to use RDS to sample two groups of migrants, from Pakistan and Poland, who had arrived in the UK within the previous 18 months, and we present an alternative approach adapted to recent migrants. Methods: We discuss how connectedness, privacy, clustering, and motivation are expected to differ among recently arrived migrants, compared to typical applications of RDS. We develop a researcher-led chain referral approach, and compare success in recruitment and indicators of representativeness to standard RDS recruitment. Results: Our researcher-led approach led to higher rates of chain-referral, and enabled us to reach population members with smaller network sizes. The researcher-led approach resulted in similar recruiter-recruit transition probabilities to traditional RDS across many demographic and social characteristics. However, we did not succeed in building up long referral chains, largely due to the lack of connectedness of our target populations and some reluctance to refer. There were some differences between the two migrant groups, with less mobile and less hidden Pakistani men producing longer referral chains. Conclusions: Chain referral is difficult to implement for sampling newly arrived migrants. However, our researcher-led adaptation shows promise for less hidden and more stable recent immigrant populations. Contribution: The paper offers an evaluation of RDS for surveying recent immigrants and an adaptation that may be effective under certain conditions.

  18. On-Chip integration of sample pretreatment and Multiplex polymerase chain reaction (PCR) for DNA analysis

    DEFF Research Database (Denmark)

    Brivio, Monica; Snakenborg, Detlef; Søgaard, E.; Ahlford, A.; Syvänen, A.-C; Kutter, Jörg Peter; Wolff, Anders

    In this paper we present a modular lab-on-a-chip system for integrated sample pre-treatment (PT) by magnetophoresis and DNA amplification by polymerase chain reaction (PCR). It consists of a polymer-based microfluidic chip mounted on a custom-made thermocycler (Figure 1) and includes a simple and...

  19. Contamination profiles of short-chain polychlorinated n-alkanes in foodstuff samples from Japan

    Energy Technology Data Exchange (ETDEWEB)

    Matsukami, Hidenori; Kurunthachalam, S.; Ohi, Etsumasa; Takasuga, Takumi [Shimadzu Techno Research, Inc., Kyoto (Japan); Iino, Fukuya; Nakanishi, Junko [National Inst. of Advanced Industrial Science and Technology, Tsukuba (Japan)

    2004-09-15

    Polychlorinated n-alkanes (PCAs) are group of chemicals manufactured by chlorination of liquid n-paraffin or paraffin wax that contain 30 to 70% chlorine by weight. Large amounts of PCAs are widely used as plasticizers for vinyl chloride, lubricants, paints, and flame retardants and number of other industrial applications. Annual global production of PCAs is approximately 300 kilo tones, with a majority having medium-carbon-chain (C14-C19) length. According to the investigation made by Kagaku Kogyo Nippon-Sha, the annual consumption of PCAs in Japan was about 83,000 tons in between 1986-2001. Short-carbon-chain (C10-C13) has been placed on the Priority Substance List under Canadian Environmental Protection Act and on the Environmental Protection Agency Toxic Release Inventory in the USA due to its potential to act as tumor promoters in mammals. Data on environment levels of PCAs is meager, nevertheless, PCAs have been measured at relatively high concentrations in biota from Sweden, biota, sediment from Canada and marine biota and human milk from the Canadian Arctic. In our earlier study, we reported concentrations of short-chain PCAs from sewage treatment plant (STP) collected from Tama River, Tokyo and river water and sediment from Tokyo and Osaka. STP influent water contained greater shortchain PCAs concentrations than STP effluent. In addition, some river water and sediment samples contained detectable concentrations of short-chain PCAs, which was similar to other industrial countries. However, there is no study conducted to explore the contamination profiles of short-chain PCAs in human foodstuff samples. In the present study, we analyzed eleven foodstuff samples that were purchased from various supermarkets in order to know the short-chain PCAs concentrations in the foodstuff and possible human total daily intake (TDI) amounts.

  20. RosettaEPR: rotamer library for spin label structure and dynamics.

    Directory of Open Access Journals (Sweden)

    Nathan S Alexander

    Full Text Available An increasingly used parameter in structural biology is the measurement of distances between spin labels bound to a protein. One limitation to these measurements is the unknown position of the spin label relative to the protein backbone. To overcome this drawback, we introduce a rotamer library of the methanethiosulfonate spin label (MTSSL into the protein modeling program Rosetta. Spin label rotamers were derived from conformations observed in crystal structures of spin labeled T4 lysozyme and previously published molecular dynamics simulations. Rosetta's ability to accurately recover spin label conformations and EPR measured distance distributions was evaluated against 19 experimentally determined MTSSL labeled structures of T4 lysozyme and the membrane protein LeuT and 73 distance distributions from T4 lysozyme and the membrane protein MsbA. For a site in the core of T4 lysozyme, the correct spin label conformation (Χ1 and Χ2 is recovered in 99.8% of trials. In surface positions 53% of the trajectories agree with crystallized conformations in Χ1 and Χ2. This level of recovery is on par with Rosetta performance for the 20 natural amino acids. In addition, Rosetta predicts the distance between two spin labels with a mean error of 4.4 Å. The width of the experimental distance distribution, which reflects the flexibility of the two spin labels, is predicted with a mean error of 1.3 Å. RosettaEPR makes full-atom spin label modeling available to a wide scientific community in conjunction with the powerful suite of modeling methods within Rosetta.

  1. Potential-Decomposition Strategy in Markov Chain Monte Carlo Sampling Algorithms

    International Nuclear Information System (INIS)

    We introduce the potential-decomposition strategy (PDS), which can he used in Markov chain Monte Carlo sampling algorithms. PDS can be designed to make particles move in a modified potential that favors diffusion in phase space, then, by rejecting some trial samples, the target distributions can be sampled in an unbiased manner. Furthermore, if the accepted trial samples are insufficient, they can be recycled as initial states to form more unbiased samples. This strategy can greatly improve efficiency when the original potential has multiple metastable states separated by large barriers. We apply PDS to the 2d Ising model and a double-well potential model with a large barrier, demonstrating in these two representative examples that convergence is accelerated by orders of magnitude.

  2. Economic Design of Acceptance Sampling Plans in a Two-Stage Supply Chain

    OpenAIRE

    Lie-Fern Hsu; Jia-Tzer Hsu

    2012-01-01

    Supply Chain Management, which is concerned with material and information flows between facilities and the final customers, has been considered the most popular operations strategy for improving organizational competitiveness nowadays. With the advanced development of computer technology, it is getting easier to derive an acceptance sampling plan satisfying both the producer's and consumer's quality and risk requirements. However, all the available QC tables and computer software determine th...

  3. Rapid Detection of Salmonella in Food and Beverage Samples by Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Radji, M.

    2010-01-01

    Full Text Available Polymerase chain reaction (PCR assay had been used to detect Salmonella in food and beverage samples using suitable primers which are based on specific invA gene of Salmonella. Twenty nine samples were collected from street food counters and some canteens in Margonda Street, Depok, West Java, Indonesia. It was found that five of twenty nine samples were detected to contain Salmonella and showed the presence of the amplified product of the size 244 bp. The method of PCR demonstrated the specificity of invA primers for detection of Salmonella as confirmed by biochemical and serological assay. The results of this study revealed that PCR was a rapid and useful tool for detection of Salmonella in food and beverage samples.

  4. Detection of Helicobacter pylori using nested polymerase chain reaction in gastric biopsy samples.

    Science.gov (United States)

    Mahajan, Divya; Jain, Anju; Singh, Varsha; Jain, A K; Rao, G R K; Nath, Gopal

    2008-07-01

    Helicobacter pylori remains a controversial organism with regards to humans, its epidemiology still unclear nearly two decades after discovery. The present study was undertaken to estimate the prevalence of the organism in the gastrointestinal tract in symptomatic and asymptomatic subjects to understand its precise natural history in India. A total of 154 specimens were a part of the study. These included gastric biopsies from peptic ulcer disease and Non ulcer dyspepsia subjects, as visualized on endoscopy, saliva and stool samples from apparently normal healthy adults. Nested polymerase chain reaction was performed using the primers Hp1, Hp2, Hp3 targeting 16S rRNA gene. A prevalence of 65.1%, 100%, 66.7%, and 73.3% respectively was observed by polymerase chain reaction. No association was observed between the H.pylori status and the disease condition of the patient. PMID:23105762

  5. Accelerating Markov chain Monte Carlo simulation by differential evolution with self-adaptive randomized subspace sampling

    Energy Technology Data Exchange (ETDEWEB)

    Vrugt, Jasper A [Los Alamos National Laboratory; Hyman, James M [Los Alamos National Laboratory; Robinson, Bruce A [Los Alamos National Laboratory; Higdon, Dave [Los Alamos National Laboratory; Ter Braak, Cajo J F [NETHERLANDS; Diks, Cees G H [UNIV OF AMSTERDAM

    2008-01-01

    Markov chain Monte Carlo (MCMC) methods have found widespread use in many fields of study to estimate the average properties of complex systems, and for posterior inference in a Bayesian framework. Existing theory and experiments prove convergence of well constructed MCMC schemes to the appropriate limiting distribution under a variety of different conditions. In practice, however this convergence is often observed to be disturbingly slow. This is frequently caused by an inappropriate selection of the proposal distribution used to generate trial moves in the Markov Chain. Here we show that significant improvements to the efficiency of MCMC simulation can be made by using a self-adaptive Differential Evolution learning strategy within a population-based evolutionary framework. This scheme, entitled DiffeRential Evolution Adaptive Metropolis or DREAM, runs multiple different chains simultaneously for global exploration, and automatically tunes the scale and orientation of the proposal distribution in randomized subspaces during the search. Ergodicity of the algorithm is proved, and various examples involving nonlinearity, high-dimensionality, and multimodality show that DREAM is generally superior to other adaptive MCMC sampling approaches. The DREAM scheme significantly enhances the applicability of MCMC simulation to complex, multi-modal search problems.

  6. Sampling based motion planning with reachable volumes: Application to manipulators and closed chain systems

    KAUST Repository

    McMahon, Troy

    2014-09-01

    © 2014 IEEE. Reachable volumes are a geometric representation of the regions the joints of a robot can reach. They can be used to generate constraint satisfying samples for problems including complicated linkage robots (e.g. closed chains and graspers). They can also be used to assist robot operators and to help in robot design.We show that reachable volumes have an O(1) complexity in unconstrained problems as well as in many constrained problems. We also show that reachable volumes can be computed in linear time and that reachable volume samples can be generated in linear time in problems without constraints. We experimentally validate reachable volume sampling, both with and without constraints on end effectors and/or internal joints. We show that reachable volume samples are less likely to be invalid due to self-collisions, making reachable volume sampling significantly more efficient for higher dimensional problems. We also show that these samples are easier to connect than others, resulting in better connected roadmaps. We demonstrate that our method can be applied to 262-dof, multi-loop, and tree-like linkages including combinations of planar, prismatic and spherical joints. In contrast, existing methods either cannot be used for these problems or do not produce good quality solutions.

  7. Application of polymerase chain reaction for detection of Legionella pneumophila in serum samples.

    Science.gov (United States)

    Alexiou-Daniel, S.; Stylianakis, A.; Papoutsi, A.; Zorbas, I.; Papa, A.; Lambropoulos, A.F.; Antoniadis, A.

    1998-03-01

    OBJECTIVE: To apply the polymerase chain reaction (PCR) to serum samples for the rapid diagnosis of Legionnaire's disease using the L5SL9 and L5SR93 primers designed to generate a 104-base-pair (bp) fragment from the 5S RNA gene of Legionella spp. The amplified product was detected by electrophoresis and by hybridization with the L5S-1-specific probe. METHODS: Single specimens of serum obtained from 24 patients with confirmed legionellosis, at different stages of their disease, were tested by PCR. Additionally, 10 serum samples from patients with no clinical symptoms of pneumonia and 10 samples from patients suffering from pneumonia caused by Mycoplasma pneumoniae, Coxiella burnetii or Chlamydia psittaci were also tested as controls in order to determine the specificity of the method. RESULTS: Of the 24 examined serum samples, the amplified products from 12 hybridized with the L5S-1 probe (sensitivity 50%). None of the negative controls was positive after PCR. No correlation was found between the day of illness and the positivity in the test. CONCLUSIONS: The PCR technique could be applied as a diagnostic tool for the rapid diagnosis of legionellosis in serum samples after modification, mainly to improve its sensitivity. PMID:11864308

  8. Pooling of porcine fecal samples for quantification of Lawsonia intracellularis by real-time polymerase chain reaction

    DEFF Research Database (Denmark)

    Pedersen, Ken Steen; Johansen, Markku; Jorsal, Sven Erik Lind;

    2014-01-01

    obtained by averaging test results from individual fecal samples in relation to a quantitative polymerase chain reaction (qPCR) test for Lawsonia intracellularis. Ten diarrheic and 10 normal fecal samples were submitted from each of 43 Danish swine herds (n = 860 fecal samples). Pools (n = 43), each...

  9. Routine application of the polymerase chain reaction for detection of Mycobacterium tuberculosis in clinical samples.

    Science.gov (United States)

    Noordhoek, G T; Kaan, J A; Mulder, S; Wilke, H; Kolk, A H

    1995-01-01

    AIM--To investigate the use of the polymerase chain reaction (PCR) in the routine laboratory for the detection of Mycobacterium tuberculosis in clinical samples. METHODS--Samples were divided and processed separately for the detection of M tuberculosis by microscopy, culture and PCR. After DNA extraction, PCR was performed with primers specific for the insertion element IS6110 and the product was analysed by agarose gel electrophoresis, Southern blotting or dot blotting and hybridisation with a digoxigenin labelled internal probe. Each sample was tested for inhibitors of Taq polymerase with the aid of an internal control. Multiple negative and positive controls were used to monitor each step of the procedure. RESULTS--The data from two laboratories, using the same operating procedures, were combined. Of 1957 specimens, 79 (4%) were culture and PCR positive, while 1839 (93.9%) were negative in both tests. Thirty specimens (1.5%) were PCR positive only and nine (0.5%) were culture positive but PCR negative. CONCLUSION--Using culture and clinical history as the gold standard, sensitivity and specificity for PCR were 92.1% and 99.8%, respectively. With elaborate precautions, PCR is a suitable and reliable method for the detection of M tuberculosis in clinical samples in a routine microbiology laboratory. Images PMID:7490312

  10. Sampling graphs with a prescribed joint degree distribution using Markov Chains.

    Energy Technology Data Exchange (ETDEWEB)

    Pinar, Ali; Stanton, Isabelle (UC Berkeley)

    2010-10-01

    One of the most influential results in network analysis is that many natural networks exhibit a power-law or log-normal degree distribution. This has inspired numerous generative models that match this property. However, more recent work has shown that while these generative models do have the right degree distribution, they are not good models for real life networks due to their differences on other important metrics like conductance. We believe this is, in part, because many of these real-world networks have very different joint degree distributions, i.e. the probability that a randomly selected edge will be between nodes of degree k and l. Assortativity is a sufficient statistic of the joint degree distribution, and it has been previously noted that social networks tend to be assortative, while biological and technological networks tend to be disassortative. We suggest that the joint degree distribution of graphs is an interesting avenue of study for further research into network structure. We provide a simple greedy algorithm for constructing simple graphs from a given joint degree distribution, and a Monte Carlo Markov Chain method for sampling them. We also show that the state space of simple graphs with a fixed degree distribution is connected via endpoint switches. We empirically evaluate the mixing time of this Markov Chain by using experiments based on the autocorrelation of each edge.

  11. Leptospira spp detection by Polymerase Chain Reaction (PCR) in clinical samples of captive black-capped Capuchin monkey (Cebus apella)

    OpenAIRE

    Scarcelli Eliana; Piatti Rosa Maria; Fedullo José Daniel Luzes; Simon Faiçal; Cardoso Maristela Vasconcellos; Castro Vanessa; Miyashiro Simone; Genovez Margareth Élide

    2003-01-01

    Leptospirosis is a widely distributed zoonosis that affects domestic and wild animals, and that has the man as the end point of its epidemiological chain. Leptospirosis diagnosis in primates is more difficult than in other animal species, as clinical signs and lesions are less evident and antibody response is detected only for short periods. The aim of this article was to describe the detection of Leptospira spp using polymerase chain reaction (PCR), in clinical samples from one captive black...

  12. Comparison of a conventional polymerase chain reaction with real-time polymerase chain reaction for the detection of neurotropic viruses in cerebrospinal fluid samples

    OpenAIRE

    M Ramamurthy; Alexander, M; Aaron, S; Kannangai, R.; Ravi, V.; Sridharan, G.; A.M. Abraham

    2011-01-01

    Purpose : To compare a conventional polymerase chain reaction (PCR) and real-time PCR for the detection of neurotropic DNA viruses. Materials and Methods : A total of 147 cerebrospinal fluid (CSF) samples was collected from patients attending a tertiary care hospital in South India for a period from 2005 to 2008. All these samples were tested using a conventional multiplex/uniplex PCR and a real-time multiplex/uniplex PCR. This technique was used to detect a large number of herpes viruses res...

  13. BORRELIA BURGDORFERI DNA IN BIOLOGICAL SAMPLES FROM PATIENTS WITH SARCOIDOSIS USING THE POLYMERASE CHAIN REACTION TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    连伟; 罗慰慈

    1995-01-01

    Polymerase chain reaction (PCR) was used to detect the presence of Borretia burgdoferi DNA in biological samples from patients with sarcoidcsis. The target DNA sequence was of chromosomal origin. The amplified DNA sequence was analyzed by agarose gel electrophoresis, PAGE with silver staining, and the identity of amplified DNA was confirmed by restriction enzyme cleavage and DNA-DNA hybridlzation with a 32P-labelled probe. The assay was sensitive to fewer than two copies of B. burgdor feri genome, even in the presence of a 104-fold excess of human eukaryotic DNA, and was also specific to different B. burgdorferl strains tested. Sera seroiogieally positive to B. burgdorferi (n=26), broncbemlveolar lavage fluid and supematant of BALF (n=26) and peripheral blood (n=9) from sarcoidosis patients were tested. The positive rate was low (4/26, 2/26, and 0/9, respectively). It was considered that DNA from B. bur gdor feri may be identified in a minority of patients with s,arcoidosis, and it may play a pathogenetic rote in such cases. More studies need to be done before advancing the hypothesis of an etiologic role of B. burgdorferi in sarcoidosis.

  14. Shear mechanical anisotropy of side chain liquid-crystal elastomers: Influence of sample preparation

    Science.gov (United States)

    Rogez, D.; Francius, G.; Finkelmann, H.; Martinoty, P.

    2006-08-01

    We study the mechanical anisotropy of a series of uniaxial side chain nematic elastomers prepared with the same chemical composition but with different preparation protocols. For all the compounds, the experiments performed as a function of temperature show no discontinuity in both G'// and G'⊥ (the labels // and ⊥ stand for the director parallel, respectively perpendicular to the shear displacement) around the nematic-isotropic (N-I) phase transition temperature determined by DSC. They also all show a small decrease in G'// starting at temperatures well above this temperature (from ˜ 4°C to ˜ 20°C depending on the compound studied) and leading to a small hydrodynamic value of the G'⊥/G'// ratio. The measurements taken as a function of frequency show that the second plateau in G'// and the associated dip in G//” expected from dynamic semi-soft elasticity are not observed. These results can be described by the de Gennes model, which predicts small elastic anisotropy in the hydrodynamic and linear regimes. They correspond to the behavior expected for compounds beyond the mechanical critical point, which is consistent with the NMR and specific heat measurements taken on similar compounds. We also show that a reduction in the cross-linking density does not change the non-soft character of the mechanical response. From the measurements taken as a function of frequency at several temperatures we deduce that the time-temperature superposition method does not apply. From these measurements, we also determine the temperature dependence of the longest relaxation time τE of the network for the situations where the director is either parallel or perpendicular to the shear velocity. Finally, we discuss the influence on the measurements of the mechanical constraint associated with the fact that the samples cannot change their shape around the pseudo phase transition, because of their strong adherence on the sample-bearing glass slides.

  15. EFFECTIVE METHOD TO EXTRACT DNA FROM ENVIRONMENTAL SAMPLES FOR POLYMERASE CHAIN REACTION AMPLIFICATION AND DNA FINGERPRINT ANALYSIS

    Science.gov (United States)

    A rapid direct-extraction method was used to obtain DNA from environmental soil samples. eat, enzymes, and guanidine isothiocyanate were utilized to lyse cells. he DNA was purified by agarose gel electrophoresis, amplified with 16S based primers by use of the polymerase chain rea...

  16. Microbiological assessment along the fish production chain of the Norwegian pelagic fisheries sector - Results from a spot sampling programme

    OpenAIRE

    Svanevik, Cecilie Smith; Roiha, Irja Sunde; Levsen, Arne; Lunestad, Bjørn Tore

    2015-01-01

    Microbes play an important role in the degradation of fish products, thus better knowledge of the microbiological conditions throughout the fish production chain may help to optimise product quality and resource utilisation. This paper presents the results of a ten-year spot sampling programme (2005–2014) of the commercially most important pelagic fish species harvested in Norway. Fish-, surface-, and storage water samples were collected from fishing vessels and processing factories. Totally ...

  17. Nanobarcoding: detecting nanoparticles in biological samples using in situ polymerase chain reaction

    Directory of Open Access Journals (Sweden)

    Eustaquio T

    2012-11-01

    Full Text Available Trisha Eustaquio, James F LearyWeldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USABackground: Determination of the fate of nanoparticles (NPs in a biological system, or NP biodistribution, is critical in evaluating an NP formulation for nanomedicine. Current methods to determine NP biodistribution are greatly inadequate, due to their limited detection thresholds. Herein, proof of concept of a novel method for improved NP detection based on in situ polymerase chain reaction (ISPCR, coined “nanobarcoding,” is demonstrated.Methods: Nanobarcoded superparamagnetic iron oxide nanoparticles (NB-SPIONs were characterized by dynamic light scattering, zeta potential, and hyperspectral imaging measurements. Cellular uptake of Cy5-labeled NB-SPIONs (Cy5-NB-SPIONs was imaged by confocal microscopy. The feasibility of the nanobarcoding method was first validated by solution-phase PCR and “pseudo”-ISPCR before implementation in the model in vitro system of HeLa human cervical adenocarcinoma cells, a cell line commonly used for ISPCR-mediated detection of human papilloma virus (HPV.Results: Dynamic light-scattering measurements showed that NB conjugation stabilized SPION size in different dispersion media compared to that of its precursor, carboxylated SPIONs (COOH-SPIONs, while the zeta potential became more positive after NB conjugation. Hyperspectral imaging confirmed NB conjugation and showed that the NB completely covered the SPION surface. Solution-phase PCR and pseudo-ISPCR showed that the expected amplicons were exclusively generated from the NB-SPIONs in a dose-dependent manner. Although confocal microscopy revealed minimal cellular uptake of Cy5-NB-SPIONs at 50 nM over 24 hours in individual cells, ISPCR detected definitive NB-SPION signals inside HeLa cells over large sample areas.Conclusion: Proof of concept of the nanobarcoding method has been demonstrated in in vitro systems, but the technique needs further

  18. Fitting a distribution to censored contamination data using Markov Chain Monte Carlo methods and samples selected with unequal probabilities.

    Science.gov (United States)

    Williams, Michael S; Ebel, Eric D

    2014-11-18

    The fitting of statistical distributions to chemical and microbial contamination data is a common application in risk assessment. These distributions are used to make inferences regarding even the most pedestrian of statistics, such as the population mean. The reason for the heavy reliance on a fitted distribution is the presence of left-, right-, and interval-censored observations in the data sets, with censored observations being the result of nondetects in an assay, the use of screening tests, and other practical limitations. Considerable effort has been expended to develop statistical distributions and fitting techniques for a wide variety of applications. Of the various fitting methods, Markov Chain Monte Carlo methods are common. An underlying assumption for many of the proposed Markov Chain Monte Carlo methods is that the data represent independent and identically distributed (iid) observations from an assumed distribution. This condition is satisfied when samples are collected using a simple random sampling design. Unfortunately, samples of food commodities are generally not collected in accordance with a strict probability design. Nevertheless, pseudosystematic sampling efforts (e.g., collection of a sample hourly or weekly) from a single location in the farm-to-table continuum are reasonable approximations of a simple random sample. The assumption that the data represent an iid sample from a single distribution is more difficult to defend if samples are collected at multiple locations in the farm-to-table continuum or risk-based sampling methods are employed to preferentially select samples that are more likely to be contaminated. This paper develops a weighted bootstrap estimation framework that is appropriate for fitting a distribution to microbiological samples that are collected with unequal probabilities of selection. An example based on microbial data, derived by the Most Probable Number technique, demonstrates the method and highlights the

  19. Rapid Detection/pathotyping of Newcastle disease virus isolates in clinical samples using real time polymerase chain reaction assay

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: Abdul Wajid, Muhammad Wasim, Tahir Yaqub, Shafqat F Rehmani, Tasra Bibi, Nadia Mukhtar, Javed Muhammad, Umar Bacha, Suliman Qadir Afridi, Muhammad Nauman Zahid, Zia u ddin, Muhammad Zubair Shabbir, Kamran Abbas & Muneer Ahmad ### Abstract In the present protocol we describe the real time reverse transcription polymerase chain reaction (rRT-PCR) assay for the rapid detection/pathotyping of Newcastle disease virus (NDV) isoaltes in clinical samples. Fusion gene and matrix ...

  20. Detection of Wuchereria bancrofti DNA in paired serum and urine samples using polymerase chain reaction-based systems

    OpenAIRE

    Camila Ximenes; Eduardo Brandão; Paula Oliveira; Abraham Rocha; Tamisa Rego; Rafael Medeiros; Ana Aguiar-Santos; João Ferraz; Christian Reis; Paulo Araujo; Luiz Carvalho; Melo, Fabio L

    2014-01-01

    The Global Program for the Elimination of Lymphatic Filariasis (GPELF) aims to eliminate this disease by the year 2020. However, the development of more specific and sensitive tests is important for the success of the GPELF. The present study aimed to standardise polymerase chain reaction (PCR)-based systems for the diagnosis of filariasis in serum and urine. Twenty paired biological urine and serum samples from individuals already known to be positive for Wuche...

  1. Detection of Adenoviruses from clinical samples in bone marrow transplant patients by nested PCR (polymerase chain reaction)

    OpenAIRE

    Fatemeh Sabagh; Michael Roggendorf

    2012-01-01

    Adenoviruses are recognized as common human pathogens that are responsible for a wide variety of infectious syndromes. Bone marrow transplant patients are prone to life threatening opportunistic infections like adenoviruses. The nested polymerase chain reaction has provided an alternative, sensitive diagnostic method for detection of Adenoviruses. In this study we developed PCR from hexon genes as rapid diagnostic method of Advs infections on different clinical samples. Adenovirus infections ...

  2. Microbiological assessment along the fish production chain of the Norwegian pelagic fisheries sector--Results from a spot sampling programme.

    Science.gov (United States)

    Svanevik, Cecilie Smith; Roiha, Irja Sunde; Levsen, Arne; Lunestad, Bjørn Tore

    2015-10-01

    Microbes play an important role in the degradation of fish products, thus better knowledge of the microbiological conditions throughout the fish production chain may help to optimise product quality and resource utilisation. This paper presents the results of a ten-year spot sampling programme (2005-2014) of the commercially most important pelagic fish species harvested in Norway. Fish-, surface-, and storage water samples were collected from fishing vessels and processing factories. Totally 1,181 samples were assessed with respect to microbiological quality, hygiene and food safety. We introduce a quality and safety assessment scheme for fresh pelagic fish recommending limits for heterotrophic plate counts (HPC), thermos tolerant coliforms, enterococci and Listeria monocytogenes. According to the scheme, in 25 of 41 samplings, sub-optimal conditions were found with respect to quality, whereas in 21 and 9 samplings, samples were not in compliance concerning hygiene and food safety, respectively. The present study has revealed that the quality of pelagic fish can be optimised by improving the hygiene conditions at some critical points at an early phase of the production chain. Thus, the proposed assessment scheme may provide a useful tool for the industry to optimise quality and maintain consumer safety of pelagic fishery products. PMID:26187839

  3. Single-Point Mutation with a Rotamer Library Toolkit: Toward Protein Engineering.

    Science.gov (United States)

    Pottel, Joshua; Moitessier, Nicolas

    2015-12-28

    Protein engineers have long been hard at work to harness biocatalysts as a natural source of regio-, stereo-, and chemoselectivity in order to carry out chemistry (reactions and/or substrates) not previously achieved with these enzymes. The extreme labor demands and exponential number of mutation combinations have induced computational advances in this domain. The first step in our virtual approach is to predict the correct conformations upon mutation of residues (i.e., rebuilding side chains). For this purpose, we opted for a combination of molecular mechanics and statistical data. In this work, we have developed automated computational tools to extract protein structural information and created conformational libraries for each amino acid dependent on a variable number of parameters (e.g., resolution, flexibility, secondary structure). We have also developed the necessary tool to apply the mutation and optimize the conformation accordingly. For side-chain conformation prediction, we obtained overall average root-mean-square deviations (RMSDs) of 0.91 and 1.01 Å for the 18 flexible natural amino acids within two distinct sets of over 3000 and 1500 side-chain residues, respectively. The commonly used dihedral angle differences were also evaluated and performed worse than the state of the art. These two metrics are also compared. Furthermore, we generated a family-specific library for kinases that produced an average 2% lower RMSD upon side-chain reconstruction and a residue-specific library that yielded a 17% improvement. Ultimately, since our protein engineering outlook involves using our docking software, Fitted/Impacts, we applied our mutation protocol to a benchmarked data set for self- and cross-docking. Our side-chain reconstruction does not hinder our docking software, demonstrating differences in pose prediction accuracy of approximately 2% (RMSD cutoff metric) for a set of over 200 protein/ligand structures. Similarly, when docking to a set of over 100

  4. Evaluation of polymerase chain reaction for the detection of Paracoccidioides brasiliensis DNA on serum samples from patients with paracoccidioidomycosis

    Directory of Open Access Journals (Sweden)

    Cecília Eugenia Charbel

    2006-03-01

    Full Text Available The aim of this study was to demonstrate the DNA of Paracoccidioides brasiliensis in human serum samples of patients with paracoccidioidomycosis using the polymerase chain reaction (PCR. The diagnosis of paracoccidioidomycosis (PCM was defined by microscopic observation of the fungus on direct exam or histopathology, culture, and serological positivity. DNA from serum of 33 patients with PCM was extracted and submitted to nested-PCR using primers from the gp 43 gene. Only one sample was positive on nested-PCR. We conclude that the prevalence of fungemia in patients with different clinical forms of PCM is low, limiting the use of serum DNA detection as an alternative diagnostic tool.

  5. Influence of EDTA and magnesium on DNA extraction from blood samples and specificity of polymerase chain reaction

    OpenAIRE

    H. Khosravinia; Ramesha, KP

    2007-01-01

    This study consisting of two trails conducted to examine the impact of initial EDTA level added to blood samples on quantity and quality of genomic DNA isolated from avian fresh blood and the influence of initial EDTA level with various levels of $MgCl_2$ added to polymerase chain reaction (PCR) final volume on amplification pattern. EDTA level added to collected blood samples had no significant impact on quantity as well as quality of extracted genomic DNA. However, higher levels of EDTA inc...

  6. Consistent single- and multi-step sampling of multivariate arrival times: A characterization of self-chaining copulas

    CERN Document Server

    Brigo, Damiano

    2012-01-01

    This paper deals with dependence across marginally-exponentially distributed arrival times, such as default times in financial modeling or inter-failure times in reliability theory. We explore the relationship between dependence and the possibility to sample final multivariate survival in a long time-interval as a sequence of iterations of local multivariate survivals along a partition of the total time interval. We find that this is possible under a form of multivariate lack of memory that is linked to a property of the survival times copula. This property defines a "self-chaining-copula", and we show that this coincides with the extreme value copulas characterization. The self-chaining condition is satisfied by the Gumbel-Hougaard copula, a full characterization of self chaining copulas in the Archimedean family, and by the Marshall-Olkin copula. We present a homogeneity characterization of the self chaining condition. The result has important practical implications for consistent single-step and multi-step...

  7. A mixture representation of π with applications in Markov chain Monte Carlo and perfect sampling

    OpenAIRE

    Hobert, James P.; Robert, Christian P.

    2004-01-01

    Let X={Xn:n=0,1,2,…} be an irreducible, positive recurrent Markov chain with invariant probability measure π. We show that if X satisfies a one-step minorization condition, then π can be represented as an infinite mixture. The distributions in the mixture are associated with the hitting times on an accessible atom introduced via the splitting construction of Athreya and Ney [Trans. Amer. Math. Soc. 245 (1978) 493–501] and Nummelin [Z. Wahrsch. Verw. Gebiete 43 (1978) 309–318]. When the small ...

  8. Alteration in sample preparation to increase the yield of multiplex Polymerase Chain Reaction assay for diagnosis of genital ulcer disease

    Directory of Open Access Journals (Sweden)

    G Rao

    2013-01-01

    Full Text Available Purpose: Genital Ulcer Disease (GUD is common sexually transmitted infection (STI. Multiple studies have shown that GUDs are strongly associated with the transmission and the acquisition of HIV infection. An accurate diagnosis of common etiology of GUD namely Herpes, syphilis and Chancroid is possible using Multiplex PCR (M-PCR. However, frequent presence of Polymerase Chain Reaction inhibitors in the ulcer swab specimen limits the performance of the assay. In order to overcome this problem, alternative specimen preparation method was used. Materials and Methods: To determine the common etiology, GUD specimens obtained under an STI operations research study were tested with M-PCR after the samples were prepared using Roche Amplicor specimen preparation kit. PCR inhibiting samples were identified from that, which showed negative results. These samples were subjected to phenol-chloroform extraction and ethanol precipitation before the conduct of M-PCR on them. Results: Of the 237 GUD specimens tested, in 145 etiologies could be detected, whereas 92 samples were found negative. Further spiking with one of the target DNA, 128 of the negative samples were found to contain the inhibitors. These 126 samples were then subjected to phenol chloroform extraction and ethanol precipitation followed by M-PCR. Using this method for sample preparation, etiology could be determined in 46 (23% additional samples. This success rate of altered sample preparation method has been lower than that has reported. Conclusion: The results indicate that sample preparation using phenol chloroform extraction and ethanol precipitation, prior to M-PCR helps to eliminate the inhibitors and increase the yield of the assay. However, being a laborious procedure, it may be used for samples giving negative results after the screening by Roche Amplicor specimen preparation kit.

  9. Leptospira spp detection by Polymerase Chain Reaction (PCR in clinical samples of captive black-capped Capuchin monkey (Cebus apella

    Directory of Open Access Journals (Sweden)

    Scarcelli Eliana

    2003-01-01

    Full Text Available Leptospirosis is a widely distributed zoonosis that affects domestic and wild animals, and that has the man as the end point of its epidemiological chain. Leptospirosis diagnosis in primates is more difficult than in other animal species, as clinical signs and lesions are less evident and antibody response is detected only for short periods. The aim of this article was to describe the detection of Leptospira spp using polymerase chain reaction (PCR, in clinical samples from one captive black-capped Capuchin monkey (Cebus apella, which presented characteristics compatible with leptospirosis (jaundice and haemorrhagic kdney in the macroscopic post-mortem examination. A friable kidney fragment and urine sample were cultured and submitted to experimental inoculation in guinea pigs and PCR using genus specific primer pair targeting the 16S rRNA region from Leptospira interrogans serovar canicola. Isolation of the agent was negative both in culture and experimental inoculation. The PCR amplification of the clinical samples showed a 330 pb amplified fragment that corresponds to the Leptospira genus. Based on these results PCR was considered an important tool for leptospira detection in nonhumam primates, more sensitive and specific than other techniques, especially considering that the viability of the pathogen was not possible. These advantages enable the detection of the leptospiras in urine and kidney, even when autolysed, frozen or badly conserved, which prevented the isolation and experimental inoculation from positive results.

  10. Detection and Enumeration of Streptococcus agalactiae from Bovine Milk Samples by Real-Time Polymerase Chain Reaction.

    Science.gov (United States)

    de Carvalho, Nara Ladeira; Gonçalves, Juliano Leonel; Botaro, Bruno Garcia; Silva, Luis Felipe de Prada E; dos Santos, Marcos Veiga

    2015-09-01

    The aim of this study was to evaluate the use of real-time polymerase chain reaction (qPCR) combined with DNA extraction directly from composite milk and bulk tank samples for detection and enumeration of Streptococcus agalactiae (SAG) causing subclinical mastitis. Dilutions of sterile reconstituted skim milk inoculated with SAG ATCC 13813 were used to establish a standard curve (cfu/mL) for the qPCR assay targeting SAG. The analytical sensitivity and repeatability of the qPCR assay were determined. Bulk tank (BTM; n = 38) and composite milk samples (CM; n = 26) collected from lactating cows with positive isolation of SAG were submitted to the qPCR protocol and SAG plate counting, with results from both methods compared. Amplification of DNA was not possible in two out of 64 samples, indicating that qPCR was able to detect SAG in 96 and 97% of BTM and CM samples, respectively. The inter-assay coefficient of variation was <5%, showing that the technique had adequate repeatability. The qPCR protocol can be a high-throughput and rapid diagnostic assay to accurately detect SAG from BTM and CM samples compared with conventional microbiological culture method. However, the evaluated qPCR protocol is not accurate for enumerating SAG in milk samples, probably due to quantification of DNA of non-viable cells. PMID:26134534

  11. Optimized nested Markov chain Monte Carlo sampling: application to the liquid nitrogen Hugoniot using density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Milton Sam [Los Alamos National Laboratory; Coe, Joshua D [Los Alamos National Laboratory; Sewell, Thomas D [UNIV OF MISSOURI-COLUMBIA

    2009-01-01

    An optimized version of the Nested Markov Chain Monte Carlo sampling method is applied to the calculation of the Hugoniot for liquid nitrogen. The 'full' system of interest is calculated using density functional theory (DFT) with a 6-31 G* basis set for the configurational energies. The 'reference' system is given by a model potential fit to the anisotropic pair interaction of two nitrogen molecules from DFT calculations. The EOS is sampled in the isobaric-isothermal (NPT) ensemble with a trial move constructed from many Monte Carlo steps in the reference system. The trial move is then accepted with a probability chosen to give the full system distribution. The P's and T's of the reference and full systems are chosen separately to optimize the computational time required to produce the full system EOS. The method is numerically very efficient and predicts a Hugoniot in excellent agreement with experimental data.

  12. Sample-Path Optimal Stationary Policies in Stable Markov Decision Chains with Average Reward Criterion

    Czech Academy of Sciences Publication Activity Database

    Cavazos-Cadena, R.; Montes-de-Oca, R.; Sladký, Karel

    2015-01-01

    Roč. 52, č. 2 (2015), s. 419-440. ISSN 0021-9002 Grant ostatní: GA AV ČR(CZ) 171396 Institutional support: RVO:67985556 Keywords : Dominated Convergence theorem for the expected average criterion * Discrepancy function * Kolmogorov inequality * Innovations * Strong sample-path optimality Subject RIV: BC - Control Systems Theory Impact factor: 0.586, year: 2014 http://library.utia.cas.cz/separaty/2015/E/sladky-0449029.pdf

  13. Markov chain Monte Carlo sampling of gene genealogies conditional on observed genetic data

    OpenAIRE

    Burkett, Kelly

    2011-01-01

    The gene genealogy is a tree describing the ancestral relationships among genes sampled from unrelated individuals. Knowledge of the tree is useful for inference of population-genetic parameters such as the mutation or recombination rate. It also has potential application in genomic mapping, as individuals with similar trait values will tend to be more closely related genetically at the location of a trait-influencing mutation. One way to incorporate genealogical trees in genetic applications...

  14. Direct polymerase chain reaction from blood and tissue samples for rapid diagnosis of bovine leukemia virus infection.

    Science.gov (United States)

    Nishimori, Asami; Konnai, Satoru; Ikebuchi, Ryoyo; Okagawa, Tomohiro; Nakahara, Ayako; Murata, Shiro; Ohashi, Kazuhiko

    2016-06-01

    Bovine leukemia virus (BLV) infection induces bovine leukemia in cattle and causes significant financial harm to farmers and farm management. There is no effective therapy or vaccine; thus, the diagnosis and elimination of BLV-infected cattle are the most effective method to eradicate the infection. Clinical veterinarians need a simpler and more rapid method of diagnosing infection, because both nested polymerase chain reaction (PCR) and real-time PCR are labor intensive, time-consuming, and require specialized molecular biology techniques and expensive equipment. In this study, we describe a novel PCR method for amplifying the BLV provirus from whole blood, thus eliminating the need for DNA extraction. Although the sensitivity of PCR directly from whole blood (PCR-DB) samples as measured in bovine blood containing BLV-infected cell lines was lower than that of nested PCR, the PCR-DB technique showed high specificity and reproducibility. Among 225 clinical samples, 49 samples were positive by nested PCR, and 37 samples were positive by PCR-DB. There were no false positive samples; thus, PCR-DB sensitivity and specificity were 75.51% and 100%, respectively. However, the provirus loads of the samples detected by nested PCR and not PCR-DB were quite low. Moreover, PCR-DB also stably amplified the BLV provirus from tumor tissue samples. PCR-DB method exhibited good reproducibility and excellent specificity and is suitable for screening of thousands of cattle, thus serving as a viable alternative to nested PCR and real-time PCR. PMID:26911373

  15. Direct polymerase chain reaction from blood and tissue samples for rapid diagnosis of bovine leukemia virus infection

    Science.gov (United States)

    NISHIMORI, Asami; KONNAI, Satoru; IKEBUCHI, Ryoyo; OKAGAWA, Tomohiro; NAKAHARA, Ayako; MURATA, Shiro; OHASHI, Kazuhiko

    2016-01-01

    Bovine leukemia virus (BLV) infection induces bovine leukemia in cattle and causes significant financial harm to farmers and farm management. There is no effective therapy or vaccine; thus, the diagnosis and elimination of BLV-infected cattle are the most effective method to eradicate the infection. Clinical veterinarians need a simpler and more rapid method of diagnosing infection, because both nested polymerase chain reaction (PCR) and real-time PCR are labor intensive, time-consuming, and require specialized molecular biology techniques and expensive equipment. In this study, we describe a novel PCR method for amplifying the BLV provirus from whole blood, thus eliminating the need for DNA extraction. Although the sensitivity of PCR directly from whole blood (PCR-DB) samples as measured in bovine blood containing BLV-infected cell lines was lower than that of nested PCR, the PCR-DB technique showed high specificity and reproducibility. Among 225 clinical samples, 49 samples were positive by nested PCR, and 37 samples were positive by PCR-DB. There were no false positive samples; thus, PCR-DB sensitivity and specificity were 75.51% and 100%, respectively. However, the provirus loads of the samples detected by nested PCR and not PCR-DB were quite low. Moreover, PCR-DB also stably amplified the BLV provirus from tumor tissue samples. PCR-DB method exhibited good reproducibility and excellent specificity and is suitable for screening of thousands of cattle, thus serving as a viable alternative to nested PCR and real-time PCR. PMID:26911373

  16. Generalized likelihood uncertainty estimation (GLUE) using adaptive Markov chain Monte Carlo sampling

    DEFF Research Database (Denmark)

    Blasone, Roberta-Serena; Vrugt, Jasper A.; Madsen, Henrik;

    2008-01-01

    estimate of the associated uncertainty. This uncertainty arises from incomplete process representation, uncertainty in initial conditions, input, output and parameter error. The generalized likelihood uncertainty estimation (GLUE) framework was one of the first attempts to represent prediction uncertainty...... within the context of Monte Carlo (MC) analysis coupled with Bayesian estimation and propagation of uncertainty. Because of its flexibility, ease of implementation and its suitability for parallel implementation on distributed computer systems, the GLUE method has been used in a wide variety of...... applications. However, the MC based sampling strategy of the prior parameter space typically utilized in GLUE is not particularly efficient in finding behavioral simulations. This becomes especially problematic for high-dimensional parameter estimation problems, and in the case of complex simulation models...

  17. Evaluation of As, Se and Zn in octopus samples in different points of sales of the distribution chain in Brazil

    International Nuclear Information System (INIS)

    Shellfish such as squid and octopus, class Cephalopoda, has high commercial value in restaurants and for export. As, Se and Zn concentrations were determined in 117 octopus acquired in different points of the distribution chain in 4 coastal cities of Sao Paulo state (Guaruja, Santos, Sao Vicente and Praia Grande)-Brazil. The methodology for elemental determination was Instrumental Neutron Activation Analysis (INAA). The element concentration in the octopus samples (wet weight) range from: 0.184 to 35.4 mg kg-1 for As, 0.203 to 2.26 mg kg-1 for Se and 4.73 to 37.4 mg kg-1 for Zn. Arsenic and Se levels were above the limit for fish established by Brazilian legislation, while Zn concentrations were in accordance with literature values. (author)

  18. Detection of Wuchereria bancrofti DNA in paired serum and urine samples using polymerase chain reaction-based systems

    Directory of Open Access Journals (Sweden)

    Camila Ximenes

    2014-12-01

    Full Text Available The Global Program for the Elimination of Lymphatic Filariasis (GPELF aims to eliminate this disease by the year 2020. However, the development of more specific and sensitive tests is important for the success of the GPELF. The present study aimed to standardise polymerase chain reaction (PCR-based systems for the diagnosis of filariasis in serum and urine. Twenty paired biological urine and serum samples from individuals already known to be positive for Wuchereria bancrofti were collected during the day. Conventional PCR and semi-nested PCR assays were optimised. The detection limit of the technique for purified W. bancrofti DNA extracted from adult worms was 10 fg for the internal systems (WbF/Wb2 and 0.1 fg by using semi-nested PCR. The specificity of the primers was confirmed experimentally by amplification of 1 ng of purified genomic DNA from other species of parasites. Evaluation of the paired urine and serum samples by the semi-nested PCR technique indicated only two of the 20 tested individuals were positive, whereas the simple internal PCR system (WbF/Wb2, which has highly promising performance, revealed that all the patients were positive using both samples. This study successfully demonstrated the possibility of using the PCR technique on urine for the diagnosis of W. bancrofti infection.

  19. [Investigation on Toxoplasma gondii by polymerase chain reaction and loop-mediated isothermal amplification in water samples from Giresun, Turkey].

    Science.gov (United States)

    Demirel, Elif; Kolören, Zeynep; Karaman, Ulkü; Ayaz, Emine

    2014-10-01

    Toxoplasmosis is generally asymptomatic in immunocompetent subjects, however serious manifestations of the disease may develop in immunocompromised patients and in pregnant women. The mean Toxoplasma gondii seroprevalence which is approximately 40% in Turkish population, indicates the high risk for the development of acute toxoplasmosis in those cases. One of the transmission ways of T.gondii is the consumption of contaminated water. The aim of this study was to detect the presence of T.gondii in the environmental and drinking water samples by using standard polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) methods. A total of 96 water samples, of them 76 were environmental water samples collected from creeks in Giresun province center and its various districts (Piraziz, Bulancak, Keşap, Espiye) and 20 from drinking water samples, were included in the study. The samples were precipitated by the aluminium sulfate method and DNAs were isolated from the pellets formed with the sucrose gradient method. PCR and LAMP were applied to the isolated DNAs, by the use of primers F3 and B3 specific to B1 gene of the parasite. In our study, T.gondii was detected in none of the drinking water samples by PCR and LAMP, however T.gondii DNAs were positive in 13.2% (10/76) of the environmental water samples. Both of the methods yielded the same results in those samples. The stations that were positive for T.gondii were Aksu creek in Giresun province center; Gelivera creek in Espiye; Yolağzı, Keşap, Keşap Login Bridge creeks in Keşap; Bulancak, Karadere and İncivez creeks in Bulancak; Piraziz and Çayırağzı creeks in Piraziz counties. Resistance of T.gondii to chlorination and the inadequacy of the filtration processes, create a serious threat among people in contact with rivers, sea and drinking waters particularly in areas with high humidity. As far as the national literature was considered, no report about the water-borne T

  20. Diagnosis of visceral leishmaniasis by the polymerase chain reaction using blood, bone marrow and lymph node samples from patients from the Sudan

    DEFF Research Database (Denmark)

    Andresen, K; Gasim, S; Elhassan, A M;

    1997-01-01

    We have evaluated the sensitivity of the polymerase chain reaction (PCR) as a diagnostic tool for Leishmania donovani using blood, bone marrow and lymph node samples from Sudanese patients with a confirmed infection. Forty patients were diagnosed by microscopic examination of bone marrow or lymph...

  1. Determining the Diagnostic Value of Mycobacterium Tuberculosis DNA in the Differentiation of Blood Samples of Patients with Active Pulmonary Tuberculosis and Healthy Controls Using Polymerase Chain Reaction

    OpenAIRE

    Abasali Niazi; Nezarali Muolai; Mosayeb Shahriar; Reza Karimian; Farzaneh Peykfalak

    2013-01-01

    Background: Tuberculosis (TB) is now a major cause of mortality and morbidity in the world. Nowadays, different methods are used to diagnose tuberculosis. Although classical microbiological methods (such as sputum smear) are specific, they have little sensitivity and the culture is also time-consuming. Using Polymerase Chain Reaction (PCR) in blood samples in terms of Mycobacterium tuberculosis DNA, this study examines diagnostic power of this test in the diagnosis of pulmonary tuberculosis c...

  2. Alteration in sample preparation to increase the yield of multiplex Polymerase Chain Reaction assay for diagnosis of genital ulcer disease

    OpenAIRE

    Rao, G.; A Das; Prabhakar, P.; V Nema; Risbud, A. R.

    2013-01-01

    Purpose: Genital Ulcer Disease (GUD) is common sexually transmitted infection (STI). Multiple studies have shown that GUDs are strongly associated with the transmission and the acquisition of HIV infection. An accurate diagnosis of common etiology of GUD namely Herpes, syphilis and Chancroid is possible using Multiplex PCR (M-PCR). However, frequent presence of Polymerase Chain Reaction inhibitors in the ulcer swab specimen limits the performance of the assay. In order to overcome this proble...

  3. Detection of Mycobacterium tuberculosis in clinical samples by two-step polymerase chain reaction and nonisotopic hybridization methods.

    OpenAIRE

    Shawar, R M; el-Zaatari, F A; Nataraj, A; Clarridge, J E

    1993-01-01

    Detection of Mycobacterium tuberculosis in clinical specimens by the polymerase chain reaction (PCR) was compared with detection by culture. A 317-bp segment within the M. tuberculosis-specific insertion sequence IS6110 was amplified. The detection limit of the PCR assay for cultured mycobacteria was 50 cells per reaction by ethidium bromide-stained agarose gel electrophoresis and 5 cells per reaction by hybridization with an oligonucleotide probe conjugated with either digoxigenin or alkalin...

  4. Effect of sample pooling and transport conditions on the clinical sensitivity of a real-time polymerase chain reaction assay for Campylobacter fetus subsp. venerealis in preputial samples from bulls.

    Science.gov (United States)

    García-Guerra, Alvaro; Waldner, Cheryl L; Pellegrino, Andrea; Macdonald, Nicole; Chaban, Bonnie; Hill, Janet E; Hendrick, Steven H

    2016-01-01

    The diagnosis of bovine genital campylobacteriosis (BGC) presents significant challenges, as traditional methods lack sensitivity when prolonged transport of samples is required. Assays of preputial samples by means of real-time polymerase chain reaction (PCR) provide good sensitivity and high throughput capabilities. However, there is limited information on the acceptable duration of transport and temperature during transport of samples. In addition, the use of pooled samples has proven to be a valuable strategy for the diagnosis of other venereal diseases in cattle. The objectives of the present study were to determine the effect of sample pooling and of transport time and temperature on the clinical sensitivity of a real-time quantitative PCR (qPCR) assay for Campylobacter fetus subsp. venerealis in preputial samples from beef bulls. Eight infected bulls and 176 virgin yearling bulls were used as the source of samples. The qPCR sensitivity was comparable for unpooled samples and pools of 5 samples, whereas sensitivity was decreased for pools of 10 samples. Sensitivity for the various pool sizes improved with repeated sampling. For shorter-term transport (2 and 48 h), sensitivity was greatest when the samples were stored at 4°C and 30°C, whereas for longer-term transport (96 h) sensitivity was greatest when the samples were stored at -20°C. The creation of pools of 5 samples is therefore a good option to decrease costs when screening bulls for BGC with the qPCR assay of direct preputial samples. Ideally the samples should be stored at 4°C and arrive at the laboratory within 48 h of collection, but when that is not possible freezing at -20°C could minimize the loss of sensitivity. PMID:26733730

  5. Polymerase chain reaction and bacteriological comparative analysis of raw milk samples and buffalo mozzarella produced and marketed in Caserta in the Campania region of Italy

    Directory of Open Access Journals (Sweden)

    Elisabetta Di Giannatale

    2009-09-01

    Full Text Available To help identify an epidemiological link between the consumption of buffalo mozzarella prepared with raw milk (not heat-treated and cases of human brucellosis, 80 samples of raw buffalo milk and 315 samples of mozzarella were tested for the presence of Brucella spp. Samples originated from Caserta, the province with the highest number of Brucella-positive buffalo herds in Campania, the region in which 96.02% of all cases of human brucellosis reported in 2000-2005 were recorded. To take into account possible seasonal variations, between February 2006 and March 2007, samples were purchased directly from 72 dairy outlets that were representative of the province. Samples were tested for Brucella spp. using the polymerase chain reaction (PCR and bacterial isolation. Samples tested negative for Brucella using both methods. Spiked samples were then prepared and tested by PCR and bacterial isolation and the sensitivity, specificity, repeatability, reproducibility and limit of detection were determined. The PCR limit of detection was below 1 colony-forming unit (cfu/g. The repeatability and reproducibility of the method were 100% (p = 0.95, the sensitivity was 96.7% (p = 0.95 and the specificity was 100% (p = 0.95.

  6. Direct diagnosis ofMycobacterium tuberculosis in blood samples of HIV infected patients by polymerase chain reaction

    OpenAIRE

    Kamatchiammal, Senthilkumar; Saravanakumar, Dhashinamoorthy; Kumarasamy, Nagalingeswaran; Solomon, Sunithi; Sritharan, Manjula; Sritharan, Venkataraman

    2000-01-01

    We have developed a simple, economical and reproducible method for processing blood samples from HIV infected patients for diagnosis of tuberculosis. The procedure was validated on 55 samples selected for tuberculosis based on clinical criteria. 52 patients had radiological changes indicative of pulmonary tuberculosis of which only 28 were positive for AFB in sputum (sensitivity 54%) and 27 for tuberculin (sensitivity 52%). 26 HIV positive patients who showed positive X-ray did not react to t...

  7. Application of headspace solid-phase microextraction followed by gas chromatography–mass spectrometry to determine short-chain alkane monocarboxylic acids in aqueous samples

    OpenAIRE

    Banel, Anna; Wasielewska, Marta; Zygmunt, Bogdan

    2010-01-01

    In this study, a procedure was developed to determine short-chain alkane monocarboxylic acids (SCMAs) in aqueous samples using headspace solid-phase microextraction (HS-SPME) followed by gas chromatography (GC) coupled with mass spectrometry (MS). A Stabilwax-DA capillary column (30 m × 0.32-mm inner diameter, 0.50-μm film thickness) was used for GC separation and a 60-μm poly(ethylene glycol) fiber was used to isolate SCMAs from water and introduce them into the gas chromatograph. Parameters...

  8. A simplified method for sample collection and DNA isolation for polymerase chain reaction detection of Trypanosoma rangeli and Trypanosoma cruzi in triatomine vectors

    Directory of Open Access Journals (Sweden)

    Evandro MM Machado

    2000-12-01

    Full Text Available Due to the overlapping distribution of Trypanosoma rangeli and T. cruzi in Central and South America, sharing several reservoirs and triatomine vectors, we herein describe a simple method to collect triatomine feces and hemolymph in filter paper for further detection and specific characterization of these two trypanosomes. Experimentally infected triatomines feces and hemolymph were collected in filter paper and specific detection of T. rangeli or T. cruzi DNA by polymerase chain reaction was achieved. This simple DNA collection method allows sample collection in the field and further specific trypanosome detection and characterization in the laboratory.

  9. Rapid detection of avian influenza virus in chicken fecal samples by immunomagnetic capture reverse transcriptase–polymerase chain reaction assay

    DEFF Research Database (Denmark)

    Dhumpa, Raghuram; Handberg, Kurt; Jørgensen, Poul Henrik;

    2011-01-01

    this study, magnetic beads were applied for immunoseparation and purification of AIV from spiked chicken fecal sample. The beads were conjugated with monoclonal antibodies against the AIV nucleoprotein, which is conserved in all the AIV. The bead-captured virus was detected by reverse transcriptase...

  10. Evaluation of nested polymerase chain reaction for the early detection of Leptospira spp. DNA in serum samples from patients with leptospirosis.

    Science.gov (United States)

    Blanco, Roberta Morozetti; Romero, Eliete Caló

    2014-04-01

    The aim of this study was to analyse the nested polymerase chain reaction (nested PCR) in human serum samples of patients with clinical manifestations of leptospirosis. The cases of leptospirosis were defined by the microagglutination test (MAT). The samples were collected in 2010. Of 1042 serum samples collected from 521 patients, 28 (5.4%) were considered positive cases of leptospirosis, and 493 (94.6%) were negative. Twenty-three confirmed cases had no MAT-detectable antibodies in the acute sample (mean of 5.6 days after onset). Nested PCR was positive in 22/23 (95.7%) patients during the acute phase of the disease, with negative results by MAT. Nested PCR was negative in all convalescent serum samples with positive results by MAT. All negative cases of leptospirosis were negative by nested PCR. The nested PCR is an alternative diagnostic tool for early detection of leptospires in sera during the first 7 days of the disease. PMID:24445157

  11. A Counterexample on Sample-Path Optimality in Stable Markov Decision Chains with the Average Reward Criterion

    Czech Academy of Sciences Publication Activity Database

    Cavazos-Cadena, R.; Montes-de-Oca, R.; Sladký, Karel

    2014-01-01

    Roč. 163, č. 2 (2014), s. 674-684. ISSN 0022-3239 Grant ostatní: PSF Organization(US) 012/300/02; CONACYT (México) and ASCR (Czech Republic)(MX) 171396 Institutional support: RVO:67985556 Keywords : Strong sample-path optimality * Lyapunov function condition * Stationary policy * Expected average reward criterion Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.509, year: 2014 http://library.utia.cas.cz/separaty/2014/E/sladky-0432661.pdf

  12. Differential Diagnosis of Entamoeba spp. in Clinical Stool Samples Using SYBR Green Real-Time Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Thiago dos Santos Gomes

    2014-01-01

    Full Text Available Amoebiasis, a disease caused by Entamoeba histolytica, is usually diagnosed by microscopic examination, which does not differentiate the morphologically identical species of the E. histolytica/E. dispar complex. Furthermore, morphologically similar species such as Entamoeba hartmanni contribute to misidentification. Therefore, there is a need for more sensitive and specific methods. This study standardized a multiplex real-time PCR system for E. histolytica and E. dispar and a single real-time PCR for E. hartmanni. The multiplex protocol detected up to 0.0143 pg of E. histolytica DNA and 0.5156 pg of E. dispar DNA, and the average melting temperature (Tm was 73°C and 70°C, respectively. For E. hartmanni, the Tm was 73°C and the amplification was successful down to 0.03 fg of plasmid DNA. Negative controls and other intestinal parasites presented no amplification. Among the 48 samples tested, E. dispar DNA was detected in 37; none exhibited E. histolytica DNA and 11 were negative in the multiplex protocol. In 4 of these 11 samples, however, E. hartmanni DNA was amplified. SYBR Green is demonstrated to be an interesting option and these combined PCR reactions can improve laboratory diagnosis of amoebiasis in developing countries.

  13. Differential diagnosis of Entamoeba spp. in clinical stool samples using SYBR green real-time polymerase chain reaction.

    Science.gov (United States)

    Gomes, Thiago Dos Santos; Garcia, Mariana Coimbra; de Souza Cunha, Flavia; Werneck de Macedo, Heloisa; Peralta, José Mauro; Peralta, Regina Helena Saramago

    2014-01-01

    Amoebiasis, a disease caused by Entamoeba histolytica, is usually diagnosed by microscopic examination, which does not differentiate the morphologically identical species of the E. histolytica/E. dispar complex. Furthermore, morphologically similar species such as Entamoeba hartmanni contribute to misidentification. Therefore, there is a need for more sensitive and specific methods. This study standardized a multiplex real-time PCR system for E. histolytica and E. dispar and a single real-time PCR for E. hartmanni. The multiplex protocol detected up to 0.0143 pg of E. histolytica DNA and 0.5156 pg of E. dispar DNA, and the average melting temperature (T(m)) was 73 °C and 70 °C, respectively. For E. hartmanni, the T(m) was 73 °C and the amplification was successful down to 0.03 fg of plasmid DNA. Negative controls and other intestinal parasites presented no amplification. Among the 48 samples tested, E. dispar DNA was detected in 37; none exhibited E. histolytica DNA and 11 were negative in the multiplex protocol. In 4 of these 11 samples, however, E. hartmanni DNA was amplified. SYBR Green is demonstrated to be an interesting option and these combined PCR reactions can improve laboratory diagnosis of amoebiasis in developing countries. PMID:24693242

  14. Identification of Common Bacterial Pathogens Causing Meningitis in Culture-Negative Cerebrospinal Fluid Samples Using Real-Time Polymerase Chain Reaction.

    Science.gov (United States)

    Khater, Walaa Shawky; Elabd, Safia Hamed

    2016-01-01

    Background. Meningitis is a serious communicable disease with high morbidity and mortality rates. It is an endemic disease in Egypt caused mainly by Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. In some settings, bacterial meningitis is documented depending mainly on positive cerebrospinal fluid (CSF) culture results or CSF positive latex agglutination test, missing the important role of prior antimicrobial intake which can yield negative culture and latex agglutination test results. This study aimed to utilize molecular technology in order to diagnose bacterial meningitis in culture-negative CSF samples. Materials and Methods. Forty culture-negative CSF samples from suspected cases of bacterial meningitis were examined by real-time polymerase chain reaction (real-time PCR) for the presence of lytA, bexA, and ctrA genes specific for Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, respectively. Results. Positive real-time PCR results for Streptococcus pneumoniae were detected in 36 (90%) of culture-negative CSF samples while no positive results for Haemophilus influenzae or Neisseria meningitidis were detected. Four (10%) samples were negative by real-time PCR for all tested organisms. Conclusion. The use of molecular techniques as real-time PCR can provide a valuable addition to the proportion of diagnosed cases of bacterial meningitis especially in settings with high rates of culture-negative results. PMID:27563310

  15. Fast Markov chain Monte Carlo sampling for sparse Bayesian inference in high-dimensional inverse problems using L1-type priors

    International Nuclear Information System (INIS)

    Sparsity has become a key concept for solving of high-dimensional inverse problems using variational regularization techniques. Recently, using similar sparsity-constraints in the Bayesian framework for inverse problems by encoding them in the prior distribution has attracted attention. Important questions about the relation between regularization theory and Bayesian inference still need to be addressed when using sparsity promoting inversion. A practical obstacle for these examinations is the lack of fast posterior sampling algorithms for sparse, high-dimensional Bayesian inversion. Accessing the full range of Bayesian inference methods requires being able to draw samples from the posterior probability distribution in a fast and efficient way. This is usually done using Markov chain Monte Carlo (MCMC) sampling algorithms. In this paper, we develop and examine a new implementation of a single component Gibbs MCMC sampler for sparse priors relying on L1-norms. We demonstrate that the efficiency of our Gibbs sampler increases when the level of sparsity or the dimension of the unknowns is increased. This property is contrary to the properties of the most commonly applied Metropolis–Hastings (MH) sampling schemes. We demonstrate that the efficiency of MH schemes for L1-type priors dramatically decreases when the level of sparsity or the dimension of the unknowns is increased. Practically, Bayesian inversion for L1-type priors using MH samplers is not feasible at all. As this is commonly believed to be an intrinsic feature of MCMC sampling, the performance of our Gibbs sampler also challenges common beliefs about the applicability of sample based Bayesian inference. (paper)

  16. Slice Sampling

    OpenAIRE

    Neal, Radford M.

    2000-01-01

    Markov chain sampling methods that automatically adapt to characteristics of the distribution being sampled can be constructed by exploiting the principle that one can sample from a distribution by sampling uniformly from the region under the plot of its density function. A Markov chain that converges to this uniform distribution can be constructed by alternating uniform sampling in the vertical direction with uniform sampling from the horizontal `slice' defined by the current vertical positi...

  17. Plan de mejoramiento para el área de logística a nivel local de la compañía RotamAgrochemical Colombia S.A.S.

    OpenAIRE

    Gómez Susa, Martha Jannett; Morales Valero, Nadine Stella; Mosquera López, Diana Milena

    2013-01-01

    El trabajo pretende diseñar un plan de mejoramiento en el área logística que agregue valor, aumente la eficiencia y mejore los procesos de almacenamiento y distribución, gestión de inventarios y control de los productos agroquímicos de la Compañía RotamAgrochemical Colombia S.A.S., se formulan algunas recomendaciones para el mejoramiento de los procesos en las Áreas de almacenamiento, inventarios y seguridad industrial

  18. Detection and quantification of Wuchereria bancrofti and Brugia malayi DNA in blood samples and mosquitoes using duplex droplet digital polymerase chain reaction.

    Science.gov (United States)

    Jongthawin, Jurairat; Intapan, Pewpan M; Lulitanond, Viraphong; Sanpool, Oranuch; Thanchomnang, Tongjit; Sadaow, Lakkhana; Maleewong, Wanchai

    2016-08-01

    Lymphatic filariasis, a mosquito-borne disease, is still a major public health problem in tropical and sub-tropical countries. Effective diagnostic tools are required for identification of infected individuals, for epidemiological assessment, and for monitoring of control programs. A duplex droplet digital polymerase chain reaction (ddPCR) was conducted to differentiate and quantify Wuchereria bancrofti DNA by targeting the long DNA repeat (LDR) element and Brugia malayi DNA by targeting the HhaI element in blood samples and mosquito vectors. The analytical sensitivity and specificity were evaluated. Our results indicated that the duplex ddPCR assay could differentiate and quantify W. bancrofti and B. malayi DNA from blood samples and mosquitoes. DNA from a single larva in 50 μl of a blood sample, or in one mosquito vector, could be detected. The analytical sensitivity and specificity for W. bancrofti are both 100 %. Corresponding values for B. malayi are 100 and 98.3 %, respectively. Therefore, duplex ddPCR is a potential tool for simultaneous diagnosis and monitoring of bancroftian and brugian filariasis in endemic areas. PMID:27085707

  19. Development of a set of multiplex standard polymerase chain reaction assays for the identification of infectious agents from aborted bovine clinical samples.

    Science.gov (United States)

    Tramuta, Clara; Lacerenza, Daniela; Zoppi, Simona; Goria, Mariella; Dondo, Alessandro; Ferroglio, Ezio; Nebbia, Patrizia; Rosati, Sergio

    2011-07-01

    The current study describes the development of a set of 5 multiplex polymerase chain reaction (mPCR) assays for the simultaneous detection of abortive infection agents in bovine fetal tissues, including Brucella spp., Leptospira spp., and Campylobacter fetus (mPCR1); Hammondia heydorni, Neospora caninum, and Toxoplasma gondii (mPCR2); Coxiella burnetii and Chlamydophila psittaci (mPCR3); Mycoplasma bovis, Mycoplasma bovigenitalium, and Ureaplasma diversum (mPCR4); and Bovine viral diarrhea virus (BVDV) and Bovine herpesvirus-1 (BoHV-1; mPCR5). The protocol was tested on different tissue samples collected from 50 aborted bovine fetuses, and it showed that out of the 50 fetuses, 7 (14%, mPCR2) were PCR-positive for N. caninum, 4 (8%, mPCR5) were PCR-positive for BVDV, and 2 (4%, mPCR4) were PCR-positive for U. diversum. The results obtained by using each multiplex PCR were 100% concordant with those obtained by using the respective PCR assays targeting single genes on the same specimens. Moreover, all multiplex PCR assays on clinical samples were compared with reference methods, obtaining a perfect accordance in all samples and confirming the validity of the set of multiplex PCR assays. The proposed set of multiplex PCR assays is, therefore, suitable for the simultaneous detection of the main infectious agents responsible for bovine abortion. PMID:21908306

  20. The use of epifluorescent microscopy and quantitative polymerase chain reaction to determine the presence/absence and identification of microorganisms associated with domestic and foreign wallboard samples

    Science.gov (United States)

    Griffin, Dale W.

    2011-01-01

    Epifluorescent microscopy and quantitative polymerase chain reaction (qPCR) were utilized to determine the presence, concentration and identification of bacteria, and more specifically sulfate reducing bacteria (SRB) in subsamples of Chinese and North American wallboard, and wallboard-mine rock. Bacteria were visible in most subsamples, which included wallboard-lining paper from each side of the wallboard, wallboard filler, wallboard tape and fragments of mined wallboard rock via microscopy. Observed bacteria occurred as single or small clusters of cells and no mass aggregates indicating colonization were noted. Universal 16S qPCR was utilized to directly examine samples and detected bacteria at concentrations ranging from 1.4 x 103 to 6.4 x 104 genomic equivalents per mm2 of paper or per gram of wallboard filler or mined rock, in 12 of 41 subsamples. Subsamples were incubated in sulfate reducing broth for ~30 to 60 days (enrichment assay) and then analyzed by universal 16S and SRB qPCR. Enrichment universal 16S qPCR detected bacteria in 32 of 41 subsamples at concentrations ranging from 1.5 x 104 to 4.2 x 107 genomic equivalents per ml of culture broth. Evaluation of enriched subsamples by SRB qPCR demonstrated that SRB were not detectable in most of the samples and if they were detected, detection was not reproducible (an indication of low concentrations, if present). Enrichment universal 16S and SRB qPCR demonstrated that viable bacteria were present in subsamples (as expected given exposure of the samples following manufacture, transport and use) but that SRB were either not present or present at very low numbers. Further, no differences in trends were noted between the various Chinese and North American wallboard samples. In all, the microscopy and qPCR data indicated that the suspected ‘sulfur emissions’ emanating from suspect wallboard samples is not due to microbial activity.

  1. Entropy and enthalpy of interaction between amino acid side chains in nanopores

    CERN Document Server

    Vaitheeswaran, S

    2014-01-01

    Understanding the stabilities of proteins in nanopores requires a quantitative description of confinement induced interactions between amino acid side chains. We use molecular dynamics simulations to study the nature of interactions between the side chain pairs ALA-PHE, SER-ASN and LYS-GLU in bulk water and in water-filled nanopores. The temperature dependence of the bulk solvent potentials of mean force and the interaction free energies in cylindrical and spherical nanopores is used to identify the corresponding entropic and enthalpic components. The entropically stabilized hydrophobic interaction between ALA and PHE in bulk water is enthalpically dominated upon confinement depending on the relative orientations between the side chains. In the case of SER-ASN, hydrogen bonded configurations that are similar in bulk water are thermodynamically distinct in a cylindrical pore, thus making rotamer distributions different from those in the bulk. Remarkably, salt bridge formation between LYS-GLU is stabilized by e...

  2. Identification of Human Adenovirus in Respiratory Samples with Luminex Respiratory Virus Panel Fast V2 Assay and Real-Time Polymerase Chain Reaction.

    Science.gov (United States)

    Esposito, Susanna; Scala, Alessia; Bianchini, Sonia; Zampiero, Alberto; Fossali, Emilio; Principi, Nicola

    2016-01-01

    In order to compare the last version of the Respiratory Virus Panel (RVP) Fast assay for human Adenovirus (hAdv) detection with a specific real-time polymerase chain reaction (qPCR), which is considered the gold standard for hAdv detection, nasopharyngeal samples collected from 309 children (age range, four months to eight years) with respiratory tract infection were tested using the RVP Fast v2 assay (Luminex Molecular Diagnostics, Inc., Toronto, ON, Canada) and a specific TaqMan qPCR to identify hAdv DNA. The RVP Fast v2 assay detected 30/61 (49.2%) hAdv infections that had been identified by real-time qPCR, demonstrating a significantly lower detection rate (p < 0.001). The sensitivity of the RVP Fast v2 assay in comparison to qPCR was lower in younger children (42.9% vs. 57.7%; Cohen's kappa coefficient, 0.53); in samples with co-infections (40.0% vs. 56.7%; Cohen's kappa coefficient, 0.52); and in samples with hAdv type C (45.9% vs. 57.1%; Cohen's kappa coefficient, 0.60). Samples with lower viral loads were associated with a significantly lower sensitivity of the RVP Fast v2 assay (35.1% vs. 68.2%, p = 0.01; Cohen's kappa coefficients, 0.49). The RVP Fast v2 assay has important limitations for the detection of hAdv and cannot be used to evaluate whether hAdvs are the main etiologic agent responsible for an outbreak or when epidemiological studies are performed. PMID:26927078

  3. Association of diverse bacterial communities in human bile samples with biliary tract disorders: a survey using culture and polymerase chain reaction-denaturing gradient gel electrophoresis methods.

    Science.gov (United States)

    Tajeddin, E; Sherafat, S J; Majidi, M R S; Alebouyeh, M; Alizadeh, A H M; Zali, M R

    2016-08-01

    Bacterial infection is considered a predisposing factor for disorders of the biliary tract. This study aimed to determine the diversity of bacterial communities in bile samples and their involvement in the occurrence of biliary tract diseases. A total of 102 bile samples were collected during endoscopic retrograde cholangiopancreatography (ERCP). Characterization of bacteria was done using culture and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) methods. Antimicrobial susceptibility of the isolates was determined based on the Clinical and Laboratory Standards Institute (CLSI) guidelines and identity of the nucleotide sequences of differentiated bands from the DGGE gels was determined based on GenBank data. In total, 41.2 % (42/102) of the patients showed bacterial infection in their bile samples. This infection was detected in 21 % (4/19), 45.4 % (5/11), 53.5 % (15/28), and 54.5 % (24/44) of patients with common bile duct stone, microlithiasis, malignancy, and gallbladder stone, respectively. Escherichia coli showed a significant association with gallstones. Polymicrobial infection was detected in 48 % of the patients. While results of the culture method established coexistence of biofilm-forming bacteria (Pseudomonas aeruginosa, E. coli, Klebsiella pneumoniae, Enterococcus spp., and Acinetobacter spp.) in different combinations, the presence of Capnocytophaga spp., Lactococcus spp., Bacillus spp., Staphylococcus haemolyticus, Enterobacter or Citrobacter spp., Morganella spp., Salmonella spp., and Helicobacter pylori was also characterized in these samples by the PCR-DGGE method. Multidrug resistance phenotypes (87.5 %) and resistance to third- and fourth-generation cephalosporins and quinolones were common in these strains, which could evolve through their selection by bile components. Ability for biofilm formation seems to be a need for polymicrobial infection in this organ. PMID:27193890

  4. Sampling the conformation of protein surface residues for flexible protein docking

    Directory of Open Access Journals (Sweden)

    Amenta Nina

    2010-11-01

    Full Text Available Abstract Background The problem of determining the physical conformation of a protein dimer, given the structures of the two interacting proteins in their unbound state, is a difficult one. The location of the docking interface is determined largely by geometric complementarity, but finding complementary geometry is complicated by the flexibility of the backbone and side-chains of both proteins. We seek to generate candidates for docking that approximate the bound state well, even in cases where there is backbone and/or side-chain difference from unbound to bound states. Results We divide the surfaces of each protein into local patches and describe the effect of side-chain flexibility on each patch by sampling the space of conformations of its side-chains. Likely positions of individual side-chains are given by a rotamer library; this library is used to derive a sample of possible mutual conformations within the patch. We enforce broad coverage of torsion space. We control the size of the sample by using energy criteria to eliminate unlikely configurations, and by clustering similar configurations, resulting in 50 candidates for a patch, a manageable number for docking. Conclusions Using a database of protein dimers for which the bound and unbound structures of the monomers are known, we show that from the unbound patch we are able to generate candidates for docking that approximate the bound structure. In patches where backbone change is small (within 1 Å RMSD of bound, we are able to account for flexibility and generate candidates that are good approximations of the bound state (82% are within 1 Å and 98% are within 1.4 Å RMSD of the bound conformation. We also find that even in cases of moderate backbone flexibility our candidates are able to capture some of the overall shape change. Overall, in 650 of 700 test patches we produce a candidate that is either within 1 Å RMSD of the bound conformation or is closer to the bound state than the

  5. Diagnosis of bovine foot and mouth disease virus by real-time polymerase chain reaction and nucleotide sequencing from outbreak herd samples in Ilesha Baruba, Kwara state, Nigeria

    Directory of Open Access Journals (Sweden)

    Olatunde Hamza Olabode

    2014-10-01

    Full Text Available Aim: Molecular diagnosis of bovine foot and mouth disease virus (FMDV from outbreak herd in Bukaru-Rontuwa, Sinawu/Tumbunya ward of Ilesha Baruba, in Kwara state-Nigeria was conducted to establish the associated serotypes and disease control plan. Materials and Methods: Purposive study was conducted in cattle outbreak herds during the dry season of January-March, 2011. Random sampling of blood and observed epithelial tissues was collected, stored in accordance with standard methods and subjected to RNA extraction and real-time reverse transcription polymerase chain reaction (rRT-PCR. Positive samples for FMDV were further subjected to reverse transcription polymerase chain reaction (RT-PCR, nucleotide sequencing using sequence primers of serotypes O, A, SAT 1-3 and gel electrophoresis. Obtained data were interpreted based on NCBI BLASTN program. Results: Foot and mouth disease (FMD-RNA extract was not found in all the blood tested with beta-actin range of Ct = 30-34. rRT-PCR assay showed two positive samples with Ct values of 18.79 and 15.28. Gel electrophoresis identified sequenced PCR amplicons as serotype A and SAT 2 respectively. Direct product sequencing confirmed SAT 2 serotype was closely related to SAT 2 isolate LIB/7/2003. Cloned RT-PCR product in pGEM-T easy vector confirmed serotype A as closely related to sequence of A/NIG/21/2009, though multiple NIG/2009 sequences were also identified as closely related. Both isolates showed marked genetic homogeneity with >93% genetic identity in the VP1 region which confirmed heterogeneity and antigenic variation nature of FMDV. Conclusion: Quasi species and subtypes of FMD serotypes A and SAT 2 similar to A/NIG/21/2009 and SAT 2/LIB/7/2003 respectively caused the reported FMD outbreaks in Fulani livestock herds investigated. A combined real-time and optimized RT-PCR protocols that would facilitate effective and timely FMD outbreak control plan based on identified serotypes is thus suggested.

  6. Determining the Diagnostic Value of Mycobacterium Tuberculosis DNA in the Differentiation of Blood Samples of Patients with Active Pulmonary Tuberculosis and Healthy Controls Using Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Abasali Niazi

    2013-10-01

    Full Text Available Background: Tuberculosis (TB is now a major cause of mortality and morbidity in the world. Nowadays, different methods are used to diagnose tuberculosis. Although classical microbiological methods (such as sputum smear are specific, they have little sensitivity and the culture is also time-consuming. Using Polymerase Chain Reaction (PCR in blood samples in terms of Mycobacterium tuberculosis DNA, this study examines diagnostic power of this test in the diagnosis of pulmonary tuberculosis compared with other standard methods. Materials and Methods: In a cross-sectional descriptive-analytic study, blood samples were taken from 40 TB patients and 40 non-TB cases. Following DNA extraction by the commercial kit QIAGEN, the PCR assay was performed using IS6110 primer.Results: In this study, there were 80 people in two groups of TB and non-TB cases. Each group composed of 14 men (35% and 26 women (65%. Sensitivity, specificity as well as positive and negative predictive values obtained 37.5, 100, 100 and 61.5%, respectively.Conclusion: Despite high costs of using PCR for TB diagnosis, sensitivity of this method is low due to various factors and cannot replace current standard methods for TB diagnosis such as smear and culture. It can only be used as a complementary method to confirm diagnosis in strongly suspected cases of tuberculosis.

  7. Development of a diagnostic real-time polymerase chain reaction assay for the detection of invasive Haemophilus influenzae in clinical samples.

    Science.gov (United States)

    Meyler, Kenneth L; Meehan, Mary; Bennett, Desiree; Cunney, Robert; Cafferkey, Mary

    2012-12-01

    Since the introduction of the Haemophilus influenzae serotype b vaccine, invasive H. influenzae disease has become dominated by nontypeable (NT) strains. Several widely used molecular diagnostic methods have been shown to lack sensitivity or specificity in the detection of some of these strains. Novel real-time assays targeting the fucK, licA, and ompP2 genes were developed and evaluated. The fucK assay detected all strains of H. influenzae tested (n = 116) and had an analytical sensitivity of 10 genome copies/polymerase chain reaction (PCR). This assay detected both serotype b and NT H. influenzae in 12 previously positive specimens (culture and/or bexA PCR) and also detected H. influenzae in a further 5 of 883 culture-negative blood and cerebrospinal fluid (CSF) samples. The fucK assay has excellent potential as a diagnostic test for detection of typeable and nontypeable strains of invasive H. influenzae in clinical samples of blood and CSF. PMID:23017260

  8. Giardia duodenalis in Damascus, Syria: Identification of Giardia genotypes in a sample of human fecal isolates using polymerase chain reaction and restriction fragment length polymorphism analyzing method.

    Science.gov (United States)

    Skhal, Dania; Aboualchamat, Ghalia; Al Nahhas, Samar

    2016-02-01

    Giardia duodenalis is a common gastrointestinal parasite that infects humans and many other mammals. It is most prevalent in many developing and industrialized countries. G. duodenalis is considered to be a complex species. While no morphological distinction among different assemblages exist, it can be genetically differentiated into eight major assemblages: A to H. The aim of this study was to determine the genetic heterogeneity of G. duodenalis in human isolates (a study conducted for the first time in Syria). 40 fecal samples were collected from three different hospitals during the hot summer season of 2014. Extraction of genomic DNA from all Giardia positive samples (based on a microscopic examination) was performed using QIAamp DNA Stool Mini Kit. β-giardin gene was used to differentiate between different Giardia assemblages. The 514 bp fragment was amplified using the Polymerase Chain Reaction method, followed by digestion in HaeIII restriction enzyme. Our result showed that genotype A was more frequent than genotype B, 27/40 (67.5%); 4/40 (10%) respectively. A mixed genotype of A+B was only detected in 9 isolates (22.5%). This is the first molecular study performed on G. duodenalis isolates in Syria in order to discriminate among the different genotypes. Further expanded studies using more genes are needed to detect and identify the Giardia parasite at the level of assemblage and sub-assemblage. PMID:26524628

  9. Development of a diagnostic real-time polymerase chain reaction assay for the detection of invasive Haemophilus influenzae in clinical samples.

    LENUS (Irish Health Repository)

    Meyler, Kenneth L

    2012-12-01

    Since the introduction of the Haemophilus influenzae serotype b vaccine, invasive H. influenzae disease has become dominated by nontypeable (NT) strains. Several widely used molecular diagnostic methods have been shown to lack sensitivity or specificity in the detection of some of these strains. Novel real-time assays targeting the fucK, licA, and ompP2 genes were developed and evaluated. The fucK assay detected all strains of H. influenzae tested (n = 116) and had an analytical sensitivity of 10 genome copies\\/polymerase chain reaction (PCR). This assay detected both serotype b and NT H. influenzae in 12 previously positive specimens (culture and\\/or bexA PCR) and also detected H. influenzae in a further 5 of 883 culture-negative blood and cerebrospinal fluid (CSF) samples. The fucK assay has excellent potential as a diagnostic test for detection of typeable and nontypeable strains of invasive H. influenzae in clinical samples of blood and CSF.

  10. Detection and differentiation of Cryptosporidium by real-time polymerase chain reaction in stool samples from patients in Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Roberta Flávia Ribeiro Rolando

    2012-06-01

    Full Text Available This study reports the first genetic characterisation of Cryptosporidium isolates in Brazil using real-time polymerase chain reaction (RT-PCR. A total of 1,197 faecal specimens from children and 10 specimens from human immunodeficiency virus-infected patients were collected between 1999-2010 and screened using microscopy. Forty-eight Cryptosporidium oocyst-positive isolates were identified and analysed using a generic TaqMan assay targeting the 18S rRNA to detect Cryptosporidium species and two other TaqMan assays to identify Cryptosporidium hominis and Cryptosporidium parvum. The 18S rRNA assay detected Cryptosporidium species in all 48 of the stool specimens. The C. parvum TaqMan assay correctly identified five/48 stool samples, while 37/48 stool specimens were correctly amplified in the C. hominis TaqMan assay. The results obtained in this study support previous findings showing that C. hominis infections are more prevalent than C. parvum infections in Brazil and they demonstrate that the TaqMan RT-PCR procedure is a simple, fast and valuable tool for the detection and differentiation of Cryptosporidium species.

  11. [Detection of Echinococcus granulosus and Echinococcus multilocularis in cyst samples using a novel single tube multiplex real-time polymerase chain reaction].

    Science.gov (United States)

    Can, Hüseyin; İnceboz, Tonay; Caner, Ayşe; Atalay Şahar, Esra; Karakavuk, Muhammet; Döşkaya, Mert; Çelebi, Fehmi; Değirmenci Döşkaya, Aysu; Gülçe İz, Sultan; Gürüz, Yüksel; Korkmaz, Metin

    2016-04-01

    Cystic echinococcosis (CE) and alveolar echinococcosis (AE) caused by Echinococcus granulosus and Echinococcus multilocularis, respectively, are important helminthic diseases worldwide as well as in our country. Epidemiological studies conducted in Turkey showed that the prevalence of CE is 291-585/100.000. It has also been showed that the seroprevalence of AE is 3.5%. For the diagnosis of CE and AE, radiological (ultrasonography, computed tomography, magnetic resonance) and serological methods, in addition to clinical findings, are being used. The definitive diagnosis relies on pathological examination When the hydatid cysts are sterile or does not contain protoscolex, problems may occur during pathological discrimination of E.granulosus and E.multilocularis species. In this study, we aimed to develop a novel multiplex real-time polymerase chain reaction (M-RT-PCR) targeting mitochondrial 12S rRNA gene of E.granulosus and E.multilocularis using Echi S (5'-TTTATGAATATTGTGACCCTGAGAT-3') and Echi A (5'-GGTCTTAACTCAACTCATGGAG-3') primers and three different probes; Anchor Ech (5'-GTTTGCCACCTCGATGTTGACTTAG-fluoroscein-3'), Granulosus (5'-LC640-CTAAGGTTTTGGTGTAGTAATTGATATTTT-phosphate-3') and Multilocularis (5'-LC705-CTGTGATCTTGGTGTAGTAGTTGAGATT-phosphate-3') that will enable the diagnosis of CE and AE in same assay. During M-RTR-PCR, plasmids containing E.granulosus (GenBank: AF297617.1) and E.multilocularis (GenBank: NC_000928.2) mitochondrial 12S rRNA regions were used as positive controls. Cysts samples of patients which were pathologically confirmed to be CE (n: 10) and AE (n: 15) and healthy human DNA samples (n: 25) as negative control as well as DNA samples of 12 different parasites (Taenia saginata, Hymenolepis nana, Trichuris trichiura, Fasciola hepatica, Enterobius vermicularis, Toxoplasma gondii, Pneumocystis jirovecii, Trichomonas vaginalis, Cryptosporidium hominis, Strongyloides stercoralis, Plasmodium falciparum, Plasmodium vivax) were used to develop M

  12. Rapid detection of cytomegalovirus in bronchoalveolar lavage fluid and serum samples by polymerase chain reaction: correlation of virus isolation and clinical outcome for patients with human immunodeficiency virus infection

    DEFF Research Database (Denmark)

    Hansen, K K; Vestbo, Jørgen; Benfield, T;

    1997-01-01

    Bronchoalveolar lavage (BAL) fluids and serum samples from 153 patients with pulmonary symptoms who were infected with human immunodeficiency virus (HIV) and underwent BAL were examined for the presence of cytomegalovirus (CMV) by conventional culture and by polymerase chain reaction (PCR) for...

  13. Accessing ns-{mu}s side chain dynamics in ubiquitin with methyl RDCs

    Energy Technology Data Exchange (ETDEWEB)

    Fares, Christophe [University of Toronto, University Health Network, Max Bell Research Center (Canada); Lakomek, Nils-Alexander [National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases (United States); Walter, Korvin F. A.; Frank, Benedikt T. C. [Max-Planck Institute for Biophysical Chemistry, Department of NMR-based Structural Biology (Germany); Meiler, Jens [Vanderbilt University, Department of Chemistry, Center of Structural Biology (United States); Becker, Stefan; Griesinger, Christian [Max-Planck Institute for Biophysical Chemistry, Department of NMR-based Structural Biology (Germany)], E-mail: cigr@nmr.mpibpc.mpg.de

    2009-09-15

    This study presents the first application of the model-free analysis (MFA) (Meiler in J Am Chem Soc 123:6098-6107, 2001; Lakomek in J Biomol NMR 34:101-115, 2006) to methyl group RDCs measured in 13 different alignment media in order to describe their supra-{tau}{sub c} dynamics in ubiquitin. Our results indicate that methyl groups vary from rigid to very mobile with good correlation to residue type, distance to backbone and solvent exposure, and that considerable additional dynamics are effective at rates slower than the correlation time {tau}{sub c}. In fact, the average amplitude of motion expressed in terms of order parameters S{sup 2} associated with the supra-{tau}{sub c} window brings evidence to the existence of fluctuations contributing as much additional mobility as those already present in the faster ps-ns time scale measured from relaxation data. Comparison to previous results on ubiquitin demonstrates that the RDC-derived order parameters are dominated both by rotameric interconversions and faster libration-type motions around equilibrium positions. They match best with those derived from a combined J-coupling and residual dipolar coupling approach (Chou in J Am Chem Soc 125:8959-8966, 2003) taking backbone motion into account. In order to appreciate the dynamic scale of side chains over the entire protein, the methyl group order parameters are compared to existing dynamic ensembles of ubiquitin. Of those recently published, the broadest one, namely the EROS ensemble (Lange in Science 320:1471-1475, 2008), fits the collection of methyl group order parameters presented here best. Last, we used the MFA-derived averaged spherical harmonics to perform highly-parameterized rotameric searches of the side chains conformation and find expanded rotamer distributions with excellent fit to our data. These rotamer distributions suggest the presence of concerted motions along the side chains.

  14. T-O, OII-OIII and OIII-OI phase boundary in oxygen-chain-equalized and order-stabilized polycrystalline pair samples of YBa2Cu3O6+x

    International Nuclear Information System (INIS)

    A comparative investigation, performed on Oxygen-Chain-equalized(k) Deintercalated [OCD]k and Intercalated [OCI]k pair-samples (k-pairs) of YBa2Cu3O6+x by resistive Tc and electron diffraction (ED) at steps Δk = 0.02--0.03, revealed that equivalent or non-equivalent microscopic oxygen-chain arrangements are produced, at the same oxygen content k, by intercalation and deintercalation of oxygen in the Cu(1)Ox chains. These arrangements manifest in Tc-singularities or Tc-splittings of the k-pairs, whose occurrence can be straightforwardly explained by taking into account the non equivalence of the structural phase diagrams of YBCO, pointed out by electron diffraction, when produced by intercalation of oxygen in the tetragonal T structure or by deintercalation from the orthorhombic OI structure. Tc-singularities are produced in the k ranges for which a superimposition of the phase diagrams occurs, whereas Tc-splittings are pointed out in correspondence of split structural regions. The maximum Tc-splitting is observed in proximity of the semiconductor-metal transition with the appearing of superconductivity related to an anti-OIII (OIII*) superstructure in intercalated samples at k = 0.30, where the corresponding deintercalated samples are tetragonal and semiconductor. This result confirms that the vanishing of the antiferromagnetic ordering, the emergence of hole doped superconductivity and the symmetry breaking at the T-O transition are nearly coincident phenomena in YBCO. However, the related critical oxygen stoichiometry is strictly dependent on the ordering parameter in the Cu(1) plane, i.e., on the formation of extended chains. The OIII* structure, for the first time observed in a systematic way at the T-O transition in intercalated samples, seems to exhibit in analogy with OII and OIII a characteristic Tc

  15. Comparison of subgingival bacterial sampling with oral lavage for detection and quantification of periodontal pathogens by real-time polymerase chain reaction

    OpenAIRE

    Boutaga, Khalil; Savelkoul, Paul H. M.; Winkel, Edwin G.; van Winkelhoff, Arie J.

    2007-01-01

    Background: Saliva has been studied for the presence of subgingival pathogens in periodontitis patients. With the anaerobic culture technique, the discrepancy between salivary recovery and subgingival presence has been significant, which makes this approach not suitable for practical use in the microbial diagnosis of periodontitis patients. The real-time polymerase chain reaction (PCR) technique represents a very sensitive technique to detect and quantify bacterial pathogens. The aim of the s...

  16. Markov chain Monte Carlo test of toric homogeneous Markov chains

    OpenAIRE

    Takemura, Akimichi; Hara, Hisayuki

    2010-01-01

    Markov chain models are used in various fields, such behavioral sciences or econometrics. Although the goodness of fit of the model is usually assessed by large sample approximation, it is desirable to use conditional tests if the sample size is not large. We study Markov bases for performing conditional tests of the toric homogeneous Markov chain model, which is the envelope exponential family for the usual homogeneous Markov chain model. We give a complete description of a Markov basis for ...

  17. Polymerase chain reaction and bacteriological comparative analysis of raw milk samples and buffalo mozzarella produced and marketed in Caserta in the Campania region of Italy

    OpenAIRE

    Elisabetta Di Giannatale; Alessandra Alessiani; Vincenza Prencipe; Osvaldo Matteucci; Tiziana Persiani; Katiuscia Zilli; Giacomo Migliorati

    2009-01-01

    To help identify an epidemiological link between the consumption of buffalo mozzarella prepared with raw milk (not heat-treated) and cases of human brucellosis, 80 samples of raw buffalo milk and 315 samples of mozzarella were tested for the presence of Brucella spp. Samples originated from Caserta, the province with the highest number of Brucella-positive buffalo herds in Campania, the region in which 96.02% of all cases of human brucellosis reported in 2000-2005 were recorded. To take into ...

  18. Sample Optimization and Identification of Signal Patterns of Amino Acid Side Chains in 2D RFDR Spectra of the α-Spectrin SH3 Domain

    Science.gov (United States)

    Pauli, Jutta; van Rossum, Barth; Förster, Hans; de Groot, Huub J. M.; Oschkinat, Hartmut

    2000-04-01

    Future structural investigations of proteins by solid-state CPMAS NMR will rely on uniformly labeled protein samples showing spectra with an excellent resolution. NMR samples of the solid α-spectrin SH3 domain were generated in four different ways, and their 13C CPMAS spectra were compared. The spectrum of a [u-13C, 15N]-labeled sample generated by precipitation shows very narrow 13C signals and resolved scalar carbon-carbon couplings. Linewidths of 16-19 Hz were found for the three alanine Cβ signals of a selectively labeled [70% 3-13C]alanine-enriched SH3 sample. The signal pattern of the isoleucine, of all prolines, valines, alanines, and serines, and of three of the four threonines were identified in 2D 13C-13C RFDR spectra of the [u-13C,15N]-labeled SH3 sample. A comparison of the 13C chemical shifts of the found signal patterns with the 13C assignment obtained in solution shows an intriguing match.

  19. A novel nested multiplex polymerase chain reaction (PCR assay for differential detection of Entamoeba histolytica, E. moshkovskii and E. dispar DNA in stool samples

    Directory of Open Access Journals (Sweden)

    Parija Subhash C

    2007-05-01

    Full Text Available Abstract Background E. histolytica, a pathogenic amoeba, is indistinguishable in its cyst and trophozoite stages from those of non-pathogenic E. moshkovskii and E. dispar by light microscopy. We have developed a nested multiplex PCR targeting a 16S-like rRNA gene for differential detection of all the three morphologically similar forms of E. histolytica, E. moshkovskii and E. dispar simultaneously in stool samples. Results The species specific product size for E. histolytica, E. moshkovskii and E. dispar was 439, 553 and 174 bp respectively, which was clearly different for all the three Entamoeba species. The nested multiplex PCR showed a sensitivity of 94% and specificity of 100% for the demonstration of E. histolytica, E. moshkovskii and E. dispar DNA in stool samples. The PCR was positive for E. histolytica, E. moshkovskii and E. dispar in a total of 190 out of 202 stool specimens (94% sensitive that were positive for E. histolytica/E. dispar/E. moshkovskii by examination of stool by microscopy and/or culture. All the 35 negative control stool samples that were negative for E. histolytica/E. dispar/E. moshkovskii by microscopy and culture were also found negative by the nested multiplex PCR (100% specific. The result from the study shows that only 34.6% of the patient stool samples that were positive for E. histolytica/E. dispar/E. moshkovskii by examination of stool by microscopy and/or culture, were actually positive for pathogenic E. histolytica and the remaining majority of the stool samples were positive for non-pathogenic E. dispar or E. moshkovskii as demonstrated by the use of nested multiplex PCR. Conclusion The present study reports a new nested multiplex PCR strategy for species specific detection and differentiation of E. histolytica, E. dispar and E. moshkovskii DNA in stool specimens. The test is highly specific, sensitive and also rapid, providing the results within 12 hours of receiving stool specimens.

  20. Social networks of men who have sex with men: a study of recruitment chains using Respondent Driven Sampling in Salvador, Bahia State, Brazil

    Directory of Open Access Journals (Sweden)

    Sandra Mara Silva Brignol

    2015-11-01

    Full Text Available Abstract Social and sexual contact networks between men who have sex with men (MSM play an important role in understanding the transmission of HIV and other sexually transmitted infections (STIs. In Salvador (Bahia State, Brazil, one of the cities in the survey Behavior, Attitudes, Practices, and Prevalence of HIV and Syphilis among Men Who Have Sex with Men in 10 Brazilian Cities, data were collected in 2008/2009 from a sample of 383 MSM using Respondent Driven Sampling (RDS. Network analysis was used to study friendship networks and sexual partner networks. The study also focused on the association between the number of links (degree and the number of sexual partners, in addition to socio-demographic characteristics. The networks’ structure potentially facilitates HIV transmission. However, the same networks can also be used to spread messages on STI/HIV prevention, since the proximity and similarity of MSM in these networks can encourage behavior change and positive attitudes towards prevention.

  1. Social networks of men who have sex with men: a study of recruitment chains using Respondent Driven Sampling in Salvador, Bahia State, Brazil.

    Science.gov (United States)

    Brignol, Sandra Mara Silva; Dourado, Inês; Amorim, Leila Denise; Miranda, José Garcia Vivas; Kerr, Lígia R F S

    2015-11-01

    Social and sexual contact networks between men who have sex with men (MSM) play an important role in understanding the transmission of HIV and other sexually transmitted infections (STIs). In Salvador (Bahia State, Brazil), one of the cities in the survey Behavior, Attitudes, Practices, and Prevalence of HIV and Syphilis among Men Who Have Sex with Men in 10 Brazilian Cities, data were collected in 2008/2009 from a sample of 383 MSM using Respondent Driven Sampling (RDS). Network analysis was used to study friendship networks and sexual partner networks. The study also focused on the association between the number of links (degree) and the number of sexual partners, in addition to socio-demographic characteristics. The networks' structure potentially facilitates HIV transmission. However, the same networks can also be used to spread messages on STI/HIV prevention, since the proximity and similarity of MSM in these networks can encourage behavior change and positive attitudes towards prevention. PMID:26648372

  2. Chain Teleportation

    OpenAIRE

    Lee, Chien-er

    2004-01-01

    By means of the idea of measurements on the crossed space-time nonlocal observables, we extend the mechanism for the two-way quantum teleportation to the chain teleportation among N spatially separated spin-1/2 systems. Since in the process only the local interactions are used, the microcausality is automatically satisfied.

  3. Comparison of real-time polymerase chain reaction with the COBAS Amplicor test for quantitation of hepatitis B virus DNA in serum samples

    Institute of Scientific and Technical Information of China (English)

    Ming Shi; Yong Zhang; Ying-Hua Zhu; Jing Zhang; Wei-Jia Xu

    2008-01-01

    AIM: To compare the clinical performance of a real-time PCR assay with the COBAS Amplicor Hepatitis B Virus (HBV) Monitor test for quantitation of HBV DNA in serum samples. METHODS: The reference sera of the Chinese National Institute for the Control of Pharmaceutical and Biological Products and the National Center for Clinical Laboratories of China, and 158 clinical serum samples were used in this study. The linearity, accuracy, reproducibility, assay time, and costs of the real-time PCR were evaluated and compared with those of the Cobas Amplicor test. RESULTS: The intra-assay and inter-assay variations of the real-time PCR ranged from 0.3% to 3.8% and 1.4% to 8.1%, respectively. The HBV DNA levels measured by the real-time PCR correlated very well with those obtained with the COBAS Amplicor test (r = 0.948). The real-time PCR HBV DNA kit was much cheaper and had a wider dynamic range. CONCLUSION: The real-time PCR assay is an excellent tool for monitoring of HBV DNA levels in patients with chronic hepatitis B.

  4. Protein side-chain resonance assignment and NOE assignment using RDC-defined backbones without TOCSY data

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Jianyang [Duke University, Department of Computer Science (United States); Zhou Pei [Duke University Medical Center, Department of Biochemistry (United States); Donald, Bruce Randall [Duke University, Department of Computer Science (United States)

    2011-08-15

    One bottleneck in NMR structure determination lies in the laborious and time-consuming process of side-chain resonance and NOE assignments. Compared to the well-studied backbone resonance assignment problem, automated side-chain resonance and NOE assignments are relatively less explored. Most NOE assignment algorithms require nearly complete side-chain resonance assignments from a series of through-bond experiments such as HCCH-TOCSY or HCCCONH. Unfortunately, these TOCSY experiments perform poorly on large proteins. To overcome this deficiency, we present a novel algorithm, called Nasca (NOE Assignment and Side-Chain Assignment), to automate both side-chain resonance and NOE assignments and to perform high-resolution protein structure determination in the absence of any explicit through-bond experiment to facilitate side-chain resonance assignment, such as HCCH-TOCSY. After casting the assignment problem into a Markov Random Field (MRF), Nasca extends and applies combinatorial protein design algorithms to compute optimal assignments that best interpret the NMR data. The MRF captures the contact map information of the protein derived from NOESY spectra, exploits the backbone structural information determined by RDCs, and considers all possible side-chain rotamers. The complexity of the combinatorial search is reduced by using a dead-end elimination (DEE) algorithm, which prunes side-chain resonance assignments that are provably not part of the optimal solution. Then an A* search algorithm is employed to find a set of optimal side-chain resonance assignments that best fit the NMR data. These side-chain resonance assignments are then used to resolve the NOE assignment ambiguity and compute high-resolution protein structures. Tests on five proteins show that Nasca assigns resonances for more than 90% of side-chain protons, and achieves about 80% correct assignments. The final structures computed using the NOE distance restraints assigned by Nasca have backbone RMSD 0

  5. Diagnostic potential of IS6110, 38kDa, 65kDa and 85B sequence-based polymerase chain reaction in the diagnosis of Mycobacterium tuberculosis in clinical samples

    Directory of Open Access Journals (Sweden)

    Negi S

    2007-01-01

    Full Text Available Purpose: The correlation between the presence of specific gene sequence of M. tuberculosis and specific diagnosis of clinical tuberculosis is not known. This study compared the results of polymerase chain reaction (PCR amplification of M . tuberculosis specific DNA sequences (IS6110, 65kDa, 38kDa and mRNA coding for 85 B protein from different clinical samples of pulmonary and extrapulmonary tuberculosis. Methods: One hundred and seventy-two clinical samples from suspected tuberculosis patients were tested for smear examination, culture (LJ and rapid BACTEC 460 TB system and PCR. PCR was performed with specific primers for the targets: IS6110, 65kDa, 38kDa and 85B. Results: Each PCR test was found to have a much higher positivity than conventional test and BACTEC culture ( P < 0.05. Smear positive samples (56 and the samples (36 showing positive results by conventional methods (smear and LJ medium culture and BACTEC were found to be positive by all PCR protocols. No significant difference was found between the four PCR protocols ( P >0.05. The primer specific for amplifying the 123bp IS6110 fragment gave the highest positivity (83%, followed by 65kDa, 38kDa and 85B RT-PCR in descending order. Conclusions: These data suggest that the presence of IS6110 correlates more closely with the diagnosis of clinical tuberculosis than that of 65kDa, 38kDa and 85B proteins.

  6. Development and evaluation of a reverse transcription-insulated isothermal polymerase chain reaction (RT-iiPCR) assay for detection of equine arteritis virus in equine semen and tissue samples using the POCKIT™ system.

    Science.gov (United States)

    Carossino, Mariano; Lee, Pei-Yu A; Nam, Bora; Skillman, Ashley; Shuck, Kathleen M; Timoney, Peter J; Tsai, Yun-Long; Ma, Li-Juan; Chang, Hsiao-Fen G; Wang, Hwa-Tang T; Balasuriya, Udeni B R

    2016-08-01

    Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory and reproductive disease of horses. Most importantly, EAV induces abortion in pregnant mares and can establish persistent infection in up to 10-70% of the infected stallions, which will continue to shed the virus in their semen. The objective of this study was to develop and evaluate a reverse transcription insulated isothermal polymerase chain reaction (RT-iiPCR) for the detection of EAV in semen and tissue samples. The newly developed assay had a limit of detection of 10 RNA copies and a 10-fold higher sensitivity than a previously described real-time RT-PCR (RT-qPCR). Evaluation of 125 semen samples revealed a sensitivity and specificity of 98.46% and 100.00%, respectively for the RT-qPCR assay, and 100.00% and 98.33%, respectively for the RT-iiPCR assay. Both assays had the same accuracy (99.2%, k=0.98) compared to virus isolation. Corresponding values derived from testing various tissue samples (n=122) collected from aborted fetuses, foals, and EAV carrier stallions are as follows: relative sensitivity, specificity, and accuracy of 88.14%, 96.83%, and 92.62% (k=0.85), respectively for the RT-qPCR assay, and 98.31%, 92.06%, and 95.08% (k=0.90), respectively for the RT-iiPCR assay. These results indicate that RT-iiPCR is a sensitive, specific, and a robust test enabling detection of EAV in semen and tissue samples with very considerable accuracy. Even though the RT-qPCR assay showed a sensitivity and specificity equal to virus isolation for semen samples, its diagnostic performance was somewhat limited for tissue samples. Thus, this new RT-iiPCR could be considered as an alternative tool in the implementation of EAV control and prevention strategies. PMID:27036504

  7. Catch Chain

    OpenAIRE

    Talbert, Robert

    2010-01-01

    Catch Chain is a book of poems that traces the journey of a Corrections Officer who attempts to combat issues of isolation, inhumane treatment of inmates and societal rejection in jails by embarking upon a cross-country road trip. However, the same issues the officer initially wrestled with begin cropping up in different cities, on various highways and in a multitude of states. The excitement and adventure of the open road runs parallel to the recurring imprisonment of the guard's mind.

  8. One-step triplex-polymerase chain reaction assay for the authentication of yellowfin (Thunnus albacares), bigeye (Thunnus obesus), and skipjack (Katsuwonus pelamis) tuna DNA from fresh, frozen, and canned tuna samples.

    Science.gov (United States)

    Michelini, Elisa; Cevenini, Luca; Mezzanotte, Laura; Simoni, Patrizia; Baraldini, Mario; De Laude, Luca; Roda, Aldo

    2007-09-19

    A one-step triplex-polymerase chain reaction (PCR)-based assay was developed to discriminate between three tuna species, Thunnus albacares, Thunnus obesus, and Katsuwonus pelamis, even in highly processed food samples such as canned or cooked tuna. Diagnostic nucleotides were identified by direct sequencing and alignment of part of the mitochondrial cytochrome b gene of 30 authenticated exemplars, which allowed us to evaluate intraspecific variation and the genetic distance between three tuna species. The assay relies on a one-step triplex-PCR reaction in which in a single tube species-specific amplification products are generated only in the presence of the correct template nucleic acid and the species of origin of the DNA is indicated by the distinctive size of the PCR product. The identification of tuna species can be performed with a good accuracy, low cost, and with potential automation for large-scale high-throughput screenings in small in-house laboratories. PMID:17711337

  9. Determine the prevalence of Brucella spp. and Leptospira spp. in blood samples by multiplex polymerase chain reaction collected from cattle, sheep and goats in herds located in provinces of Iran

    Directory of Open Access Journals (Sweden)

    Faham Khamesipour

    2014-05-01

    Full Text Available Leptospirosis and brucellosis are common zoonosis that affect many species of mammals mostly causing economical losses. Further, very important fact is huge danger for human and animal health around the world. The purpose of the study is to determine the prevalence of Brucella spp. and Leptospira spp. using multiplex polymerase chain reaction (mPCR method, in blood samples collected from cattle, sheep and goats. In this study, a total number of 250 blood samples (5 cc of blood with ethilen diamin tetra asetic acid were collected randomly from 100 cattle, 80 sheep and 70 goats located on 6 herds in Chaharmahal Va Bakhtiari and Esfahan provinces, Iran. After DNA extraction and setting of mPCR for Brucella spp. and Leptospira spp. mPCR products were screened. The DNA of these microorganisms was detected by multiplex PCR from 31 and 21 out of 100 cattle, respectively. Four of 70 goat’s blood samples from goat breeding farms were positive for Leptospira spp. and 11 were positive for Brucella spp. Out of 80 sheep blood samples 23 were positive for Brucella spp. and 14 for Leptospira spp. The results of the present study show ruminant as an important reservoir for transmission of these zoonotic diseases to humans in Iran. mPCR has the ability to concurrently detect both Brucella and Leptospira species from blood samples of ruminants. The convenience and the possibility of detection of both bacteria at a time, strongly support the use of this mPCR for routine diagnostics.

  10. The development and empirical testing of a pressure/ response model of green supply chain management amongst a cross-sectoral sample of members of The Chartered Institute of Purchasing and Supply.

    OpenAIRE

    Holt, Diane Lesley

    2005-01-01

    This study develops and empirically tests a model of factors determining green supply chain management practices in organisations. Previous research on aspects of green supply chain management is dominated by anecdotal, sector specific studies that examine specific aspects of the supply chain, such as purchasing or logistics. Many argue this field is embryonic and lacking a structured integrative framework of research. This study addresses this gap by focussing on a whole supply chain appr...

  11. A Rapid and Sensitive UPLC-MS/MS-Method for the Separation and Quantification of Branched-Chain Amino Acids from Dried Blood Samples of Patients with Maple Syrup Urine Disease (MSUD

    Directory of Open Access Journals (Sweden)

    Ralph Fingerhut

    2016-06-01

    Full Text Available Newborn screening for MSUD is a special challenge since patients with MSUD can metabolically decompensate rapidly without adequate treatment within the first two weeks of life. However, the screening method does not detect the actual marker metabolite (alloisoleucine specifically, but only as part of the group of the other isobaric amino acids leucine, isoleucine and hydroxyproline. We describe a sensitive and rapid second-tier UPLC-MS/MS method to determine branched-chain amino acids from the initial extraction of the screening sample. Quantification is based on a seven-point calibration curve. Reference ranges (mean ± SD in µmol/L were determined from 179 normal, not pre-selected samples from the newborn screening: leucine: 72 ± 27; isoleucine: 37 ± 19; valine: 98 ± 46; hydroxyproline: 23 ± 13. The concentration of alloisoleucine was below the detection limit in about 55% of the cases, and the highest concentration was 1.9 µmol/L. In all 30 retrospectively studied screening samples from patients with confirmed MSUD the concentration of alloisoleucine was significantly increased. In 238 samples with false-positive newborn screening due to a significant increase in the combined concentration of leucine + isoleucine + alloisoleucine + hydroxyproline (400 to >4000 µmol/L, alloisoleucine was below 6.5 µmol/L (n = 57 or not detectable (n = 181. The application of this assay markedly reduces the false-positive rate and the associated anxiety and costs. It is also suitable for routinely monitoring blood spots of patients with MSUD.

  12. Effect of gamma radiation on the growth of Aspergillus Flavus aflatoxins producer and on the use of polymerase chain reaction technique (PCR) in samples of maize grains artificially inoculated

    International Nuclear Information System (INIS)

    The aim of this present study was to verify the effects of gamma radiation on the growth of Aspergillus flavus Link aflatoxins producer; to demonstrate the application of Polymerase Chain Reaction (PCR) technique in the diagnostic of A. Flavus, as well to verify the effect of radiation in the profile of DNA bands. Twenty samples of grains maize with 200 g each were individually irradiated with 20 kGy, to eliminate the microbial contamination. In following, the samples were inoculated with an toxigenic A. flavus (1x106 spores/ml), incubated for 15 days at 25 deg C with a relative humidity of around 97,5% and irradiated with 0, 2; 5 and 10 kGy. The samples, 5 to each dose of irradiation, were individually analyzed for the number of fungal cells, water activity, viability test (fluorescein diacetate and ethidium bromide), PCR and aflatoxins (AFB) detection. The results showed that the doses used were effective in reducing the number of Colony Forming Units (CFU/g) mainly the doses of 5 and 10 kGy. In addition, the viability test showed a decrease of viable cells with increase of irradiation doses. The reduction of AFB1 and AFB-2, was more efficient with the use of 2 kGy in comparison with the dose of 5 kGy, while the dose of 10 kGy, degraded the aflatoxins. Thereby, it was observed that AFB2 showed to be more radiosensitive. The use of PCR technique showed the presence of DNA bands, in all samples. (author)

  13. Leptospira spp detection by Polymerase Chain Reaction (PCR) in clinical samples of captive black-capped Capuchin monkey (Cebus apella) Detecção de Leptospira spp pela técnica da reação da polimerase em cadeia (PCR) em amostras clínicas de macaco prego (Cebus apella) criado em cativeiro

    OpenAIRE

    Eliana Scarcelli; Rosa Maria Piatti; José Daniel Luzes Fedullo; Faiçal Simon; Maristela Vasconcellos Cardoso; Vanessa Castro; Simone Miyashiro; Margareth Élide Genovez

    2003-01-01

    Leptospirosis is a widely distributed zoonosis that affects domestic and wild animals, and that has the man as the end point of its epidemiological chain. Leptospirosis diagnosis in primates is more difficult than in other animal species, as clinical signs and lesions are less evident and antibody response is detected only for short periods. The aim of this article was to describe the detection of Leptospira spp using polymerase chain reaction (PCR), in clinical samples from one captive black...

  14. Chain reaction

    International Nuclear Information System (INIS)

    Chain Reaction is a work of recent American political history. It seeks to explain how and why America came to depend so heavily on its experts after World War II, how those experts translated that authority into political clout, and why that authority and political discretion declined in the 1970s. The author's research into the internal memoranda of the Atomic Energy Commission substantiates his argument in historical detail. It was not the ravages of American anti-intellectualism, as so many scholars have argued, that brought the experts back down to earth. Rather, their decline can be traced to the very roots of their success after World War II. The need to over-state anticipated results in order to garner public support, incessant professional and bureaucratic specialization, and the sheer proliferation of expertise pushed arcane and insulated debates between experts into public forums at the same time that a broad cross section of political participants found it easier to gain access to their own expertise. These tendencies ultimately undermined the political influence of all experts. (author)

  15. Crater Chains

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] The large crater at the top of this THEMIS visible image has several other craters inside of it. Most noticeable are the craters that form a 'chain' on the southern wall of the large crater. These craters are a wonderful example of secondary impacts. They were formed when large blocks of ejecta from an impact crashed back down onto the surface of Mars. Secondaries often form radial patterns around the impact crater that generated them, allowing researchers to trace them back to their origin.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.Image information: VIS instrument. Latitude 19.3, Longitude 347.5 East (12.5 West). 19 meter/pixel resolution.

  16. Graphs: Associated Markov Chains

    OpenAIRE

    Murthy, Garimella Rama

    2012-01-01

    In this research paper, weighted / unweighted, directed / undirected graphs are associated with interesting Discrete Time Markov Chains (DTMCs) as well as Continuous Time Markov Chains (CTMCs). The equilibrium / transient behaviour of such Markov chains is studied. Also entropy dynamics (Shannon entropy) of certain structured Markov chains is investigated. Finally certain structured graphs and the associated Markov chains are studied.

  17. Elastic Behavior of Polymer Chains

    Institute of Scientific and Technical Information of China (English)

    Teng Lu; Tao Chen; Hao-jun Liang

    2008-01-01

    The elastic behavior of the polymer chain was investigated in a three-dimensional off-lattice model. We sample more than 109 conformations of each kind of polymer chain by using a Monte Carlo algorithm, then analyze them with the non-Gaussian theory of rubberlike elasticity, and end with a statistical study. Through observing the effect of the chain flexibility and the stretching ratio on the mean-square end-to-end distance,the average energy, the average Helmholtz free energy, the elastic force, the contribution of energy to the elastic force, and the entropy contribution to elastic force of the polymer chain, we find that a rigid polymer chain is much easier to stretch than a flexible polymer chain. Also, a rigid polymer chain will become difficult to stretch only at a quite high stretching ratio because of the effect of the entropy contribution.These results of our simulation calculation may explain some of the macroscopic phenomena of polymer and biomacromolecular elasticity.

  18. qPCR (quantitative polymerase chain reaction) for the quantification of bacteriophages in stream water samples to investigate hydrological processes: a proof-of-concept study in the Huewelerbach experimental catchment (Luxembourg)

    Science.gov (United States)

    Antonelli, Marta; Narayanan Balasubramanian, Mukundh; Ogorzaly, Leslie; Pfister, Laurent

    2016-04-01

    Albeit recent technological developments (e.g. field deployable instruments operating at high temporal frequencies), experimental hydrology is a discipline that remains measurement limited. From this perspective, trans-disciplinary approaches may create valuable opportunities to enlarge the amount of tools available for investigating hydrological processes. Bacteriophages have been widely used in hydrology as biological tracer for investigating colloid transport and contamination of ground water systems. However, there are only a few studies focusing on the employability of bacteriophages as surface water tracers (i.e. phage transport, system functioning). Here, we present a proof-of-concept study carried out in the Huewelerbach catchment in Luxembourg in December 2015. The aim of this study was to investigate how viral particles can be used to detect hydrological connectivity between the riparian zone/river bank and the stream during rainfall events. Moreover, this study is one of the first attempts for applying the qPCR (quantitative polymerase chain reaction) technique for the quantification of bacteriophages in stream water samples to investigate hydrological processes. This technique is very sensitive and has a large dynamic range - enhancing ease and speed of phage detection. We used two different male-specific coliphages (GA phage, genogroup II and SP phage, genogroup IV). Two litres of GA phage were injected directly in the stream as a slug injection and two litres of SP phage were poured next to the river bank (alluvial deposition) close to the injection point. We also added NaCl (200 g) to both phage suspensions. We collected stream water samples 100 m and 500 m downstream (i.e. catchment outlet) of the injection point for one week. Phages were concentrated through ultracentrifugation of 100 ml of water sample followed by quantification via qPCR. Conductivity in stream water was monitored for the entire duration of the experiment. Discharge was monitored

  19. Health supply chain management.

    Science.gov (United States)

    Zimmerman, Rolf; Gallagher, Pat

    2010-01-01

    This chapter gives an educational overview of: * The actual application of supply chain practice and disciplines required for service delivery improvement within the current health environment. * A rationale for the application of Supply Chain Management (SCM) approaches to the Health sector. * The tools and methods available for supply chain analysis and benchmarking. * Key supply chain success factors. PMID:20407173

  20. Silicone chain extender

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a silicone chain extender, more particularly a chain extender for silicone polymers and copolymers, to a chain extended silicone polymer or copolymer and to a functionalized chain extended silicone polymer or copolymer, to a method for the preparation thereof and...

  1. Accordion-like oscillation of contracted and stretched helices of polyacetylenes synchronized with the restricted rotation of side chains.

    Science.gov (United States)

    Yoshida, Yoshiaki; Mawatari, Yasuteru; Motoshige, Asahi; Motoshige, Ranko; Hiraoki, Toshifumi; Wagner, Manfred; Müllen, Klaus; Tabata, Masayoshi

    2013-03-13

    A chiral substituted acetylene, (s)-2-octyl propiolate, was stereoregularly polymerized using a catalyst, [Rh(nbd)Cl]2, at 40 °C in methanol to give the corresponding helical polymer, Ps2OcP. The changes of (1)H and (13)C NMR spectra in line shapes and splitting patterns were consistently interpreted in terms of restricted rotation around the ester O-*C bond, ~O-*C(ε)H(ε)(R)~, R = a branched CH(ε)3 in the ester side chains rather than the helix inversion with the aid of a 3-site jump model. Three peaks due to the branched methyl H(ε) proton and its C(η) carbon observed at 0 °C suggested the formation of three rotamers called A, B, and C, based on the presence of the contracted helix and stretched helix forms that have an intrinsic helical pitch. Furthermore, an accordion-like helix oscillation (HELIOS) along the main chain axis was proposed to explain the temperature dependence spectral changes observed in (1)H and (13)C NMR, UV-vis, and circular dicromism (CD) spectra. The temperature dependence UV-vis and CD spectra of Ps2OcP corroborate the presence of contracted and stretched one-handed helix sense polymers in solution in which the helical pitches and their persistence lengths depend on the temperature. PMID:23402213

  2. FragBuilder

    DEFF Research Database (Denmark)

    Christensen, Anders Steen; Hamelryck, Thomas Wim; Jensen, Jan Halborg

    2014-01-01

    . Additionally the library also offers sampling of backbone conformations and side chain rotamer conformations from continuous distributions. The generated peptides can then be geometry optimized by the MMFF94 molecular mechanics force field via convenient functions inside the library. Finally, it is possible to...

  3. COFFEE COMMODITY CHAIN

    OpenAIRE

    Tine Olsen; Brett Inder

    2008-01-01

    To explain the value added along the coffee commodity chain we propose and estimate a theoretical model of the coffee commodity chain. The theoretical model consists of four markets and five agents in the coffee commodity chain and predicts that prices in the coffee commodity chain move together but are also influenced by income, technology and production. A vector error correction model is used to test the theoretical predictions. In addition to the theoretical conclusions the empirical mode...

  4. The Global Value Chain

    DEFF Research Database (Denmark)

    Sørensen, Olav Jull

    The conference paper aims to develop the global value chain concept by including corporate internal value adding activities and competition to the basic framework in order to turn the global value chain into a strategic management tool......The conference paper aims to develop the global value chain concept by including corporate internal value adding activities and competition to the basic framework in order to turn the global value chain into a strategic management tool...

  5. Chain-Chain Based Routing Protocol

    Directory of Open Access Journals (Sweden)

    Samia A Ali

    2011-05-01

    Full Text Available Wireless sensor network (WSN is an emerging technology for monitoring physical world. WSNs consist of large numbers of sensor nodes operated by battery mostly in harsh environment. Thus energy conservation is a primary issue for organization of these sensor nodes. Another crucial issue is the data delivery time by sensor nodes to the sink node, especially in Military, medical fields, and security monitoring systems where minimum delay is desirable. Number of protocols has been proposed in the literature for routing. One of such protocols is the cluster based routing protocol LEACH (low energy adaptive clustering hierarchy. LEACH protocol organizes WSN into a set of clusters and a periodic voting for cluster head is performed in order to be evenly distributed among all the sensors of the WSN. This periodical cluster head voting in LEACH, however, consumes an amount of non-negligible energy and other resources. For energy conservation, PEGASIS (power efficient gathering in sensor information systems a near optimal chain-based protocol has been proposed, however, it is faced with the challenge of long delay for the transmitted data. Another routing protocol called CCM (Chain-Cluster based Mixed routing, which is mainly a hybrid of LEACH and PEGASIS is proposed, the consumed energy increases as network size increases. In this paper, we propose an efficient routing protocol called CCBRP (Chain-Chain based routing protocol, it achieves both minimum energy consumption and minimum delay. The CCBRP protocol mainly divides a WSN into a number of chains (Greedy algorithm is used to form each chain as in PEGSIS protocol and runs in two phases. In the first phase, sensor nodes in each chain transmit data to their chain leader nodes in parallel. In the second phase, all chain leader nodes form a chain (also, using Greedy algorithm and choose randomly a leader node then all chain leader nodes send their data to this chosen leader node. This chosen leader node

  6. Empirical Research on Associations among Information Technology, Supply Chain Robustness and Supply Chain Performance

    OpenAIRE

    Xinrui Zhang; Hengshan Wang

    2011-01-01

    Supply chain reliability and ability to do with risks are important research fields in SCM. Although it is intuitivethat supply chain’s ability to resist risks is likely to have a positive impact on supply chain performance, there islittle systematic analysis and documentation of the magnitude of these impacts in the literature. This paperempirically documents the associations among information technology, supply chain robustness, and supplychain performance. Based on a sample of 186 qu...

  7. Discrete Quantum Markov Chains

    CERN Document Server

    Faigle, Ulrich

    2010-01-01

    A framework for finite-dimensional quantum Markov chains on Hilbert spaces is introduced. Quantum Markov chains generalize both classical Markov chains with possibly hidden states and existing models of quantum walks on finite graphs. Quantum Markov chains are based on Markov operations that may be applied to quantum systems and include quantum measurements, for example. It is proved that quantum Markov chains are asymptotically stationary and hence possess ergodic and entropic properties. With a quantum Markov chain one may associate a quantum Markov process, which is a stochastic process in the classical sense. Generalized Markov chains allow a representation with respect to a generalized Markov source model with definite (but possibly hidden) states relative to which observables give rise to classical stochastic processes. It is demonstrated that this model allows for observables to violate Bell's inequality.

  8. Gushing metal chain

    Science.gov (United States)

    Belyaev, Alexander; Sukhanov, Alexander; Tsvetkov, Alexander

    2016-03-01

    This article addresses the problem in which a chain falls from a glass from some height. This phenomenon demonstrates a paradoxical rise of the chain over the glass. To explain this effect, an initial hypothesis and an appropriate theory are proposed for calculating the steady fall parameters of the chain. For this purpose, the modified Cayley's problem of falling chain given its rise due to the centrifugal force of upward inertia is solved. Results show that the lift caused by an increase in linear density at the part of chain where it is being bent (the upper part) is due to the convergence of the chain balls to one another. The experiments confirm the obtained estimates of the lifting chain.

  9. Crater chains on Mercury

    Science.gov (United States)

    Shevchenko, V.; Skobeleva, T.

    After discovery of disruption comet Shoemaker-Levy 9 into fragment train before it's collision with Jupiter there was proposed that linear crater chains on the large satellites of Jupiter and on the Moon are impact scars of past tidally disrupted comets.It's known that radar images have revealed the possible presence of water ice deposits in polar regions of Mercury. Impacts by a few large comets seem to provide the best explanation for both the amount and cleanliness of the ice deposits on Mercury because they have a larger volatile content that others external sources, for example, asteroid. A number of crater chains on the surface of Mercury are most likely the impact tracks of "fragment trains" of comets tidally disrupted by Sun or by Mercury and are not secondary craters. Mariner 10 image set (the three Mariner 10 flybys in 1974-1975) was used to recognize the crater chains these did not associate with secondary crater ejecta from observed impact structures. As example, it can be shown such crater chain located near crater Imhotep and crater Ibsen (The Kuiper Quadrangle of Mercury). Resolution of the Mariner 10 image is about 0.54 km/pixel. The crater chain is about 50 km long. It was found a similar crater chain inside large crater Sophocles (The Tolstoj Quadrangle of Mercury). The image resolution is about 1.46 km/pixel. The chain about 50 km long is located in northen part of the crater. Image resolution limits possibility to examine the form of craters strongly. It seems the craters in chains have roughly flat floor and smooth form. Most chain craters are approximately circular. It was examined many images from the Mariner 10 set and there were identified a total 15 crater chains and were unable to link any of these directly to any specific large crater associated with ejecta deposits. Chain craters are remarkably aligned. All distinguished crater chains are superposed on preexisting formations. A total of 127 craters were identified in the 15 recognized

  10. Electric Power Supply Chain Management Addressing Climate Change

    DEFF Research Database (Denmark)

    Wang, Xiao-Hui; Cong, Ronggang

    2012-01-01

    change. The study compared the difference between electric power supply chain management and traditional supply chain management. Furthermore, some possible research topics are addressed. The aim of this paper was to promote the application of supply chain management in the China electricity sector......Supply chain management played a critical role in the electric power industrial chain optimization. The purpose of this paper was to review a sample of the literature relating to supply chain management and its possible applications in electricity power system, especially in the context of climate...... optimizations and brought a change in the related government policy options....

  11. A Markov Chain Monte Carlo technique to sample transport and source parameters of Galactic cosmic rays: II. Results for the diffusion model combining B/C and radioactive nuclei

    CERN Document Server

    Putze, A; Maurin, D

    2010-01-01

    On-going measurements of the cosmic radiation (nuclear, electronic, and gamma-ray) are shedding new light on cosmic-ray physics. A comprehensive picture of these data relies on an accurate determination of the transport and source parameters of propagation models. A Markov Chain Monte Carlo is used to obtain these parameters in a diffusion model. From the measurement of the B/C ratio and radioactive cosmic-ray clocks, we calculate their probability density functions, with a special emphasis on the halo size L of the Galaxy and the local underdense bubble of size r_h. The analysis relies on the USINE code for propagation and on a Markov Chain Monte Carlo technique (Putze et al. 2009, paper I of this series) for the parameter determination. As found in previous studies, the B/C best-fit model favours diffusion/convection/reacceleration (Model III) over diffusion/reacceleration (Model II). A combined fit on B/C and the isotopic ratios (10Be/9Be, 26Al/27Al, 36Cl/Cl) leads to L ~ 8 kpc and r_h ~ 120 pc for the bes...

  12. Supply Chain Management og Supply Chain costing

    DEFF Research Database (Denmark)

    Nielsen, Steen; Mortensen, Ole

    2002-01-01

    Formålet med denne artikel er at belyse de muligheder som ligger i at integrere virksomhedens økonomiske styring med begrebet Supply Chain Management (SCM). Dette søges belyst ved først at beskrive den teoretiske ramme, hvori SCM indgår. Herefter analyseres begrebet Supply Chain Costing (SCC) som...... Århus. Et resultat er, at via begrebet Supply Chain Costing skabes der mulighed for at måle logistikkædens aktiviteter i kr./øre. Anvendelsen af denne information har også strategisk betydning for at kunne vælge kunde og leverandør. Ved hjælp af integrationen skabes der også helt nye mulighed for at...

  13. Food supply chains

    OpenAIRE

    Zhou, Qian

    2011-01-01

    The dissertation analyses food waste in global supply chain. From the related managerial literature, the process of supply chain operation, from agriculture, manufacturing, warehouses, retailers to customers are explained clearly. Then the reasons and characteristics of food wastes in any point of food supply chain are analyzed. From some case studies and questionnaire investigation, some corresponding methods to reduce food waste are put forward in the following. Lastly, in terms of method s...

  14. Supply chain components

    Directory of Open Access Journals (Sweden)

    Vieraşu, T.

    2011-01-01

    Full Text Available In this article I will go through three main logistics components, which are represented by: transportation, inventory and facilities, and the three secondary logistical components: information, production location, price and how they determine performance of any supply chain. I will discuss then how these components are used in the design, planning and operation of a supply chain. I will also talk about some obstacles a supply chain manager may encounter.

  15. Supply Chain Collaboration

    OpenAIRE

    Meca, Ana; Timmer, Judith

    2008-01-01

    In this chaper, we have reviewed and surveyed the literature on supply chain collaboration. As mentioned above, the game theory models that include cooperative behaviour among retailers seem to be a natural framework to model cooperation (collaboration) in supply chains that consist of a supplier and a finite number of retailers. Various researchers in this area have already adopted several cooperative models dealing with supply chain coordination, and it is expected to see many more in the n...

  16. Supply chain components

    OpenAIRE

    Vieraşu, T.; Bălăşescu, M.

    2011-01-01

    In this article I will go through three main logistics components, which are represented by: transportation, inventory and facilities, and the three secondary logistical components: information, production location, price and how they determine performance of any supply chain. I will discuss then how these components are used in the design, planning and operation of a supply chain. I will also talk about some obstacles a supply chain manager may encounter.

  17. Sustainable Supply Chain Management

    OpenAIRE

    Geentjens, Marlies

    2013-01-01

    This project investigates the phenomena Sustainable Supply Chain Management. The point of departure is Supply Chain Management, which we analyse in order to lock into an understanding of the development that occur when implementing sustainability. In the quest for higher understanding of the interlocking mechanisms of supply chain management, we combine a theoretical approach to the developmnent of sustainability with some relevant case-examples (mainly depicting IKEA). This focal point g...

  18. Economy, market and chain

    OpenAIRE

    Sukkel, W.; Hommes, M.

    2009-01-01

    In their pursuit of growth and professionalisation, the Dutch organic sector focuses primarily on market development. But how do you stimulate the market for organic foods? This is the subject of many research projects concerning market, consumer preferences and the supply chain. These projects focus specifically at consumer purchasing behaviour, product development, supply chain formation and minimising cost price. As a rule, this research takes place in close cooperation with chain actors

  19. Value Chain Engineering

    DEFF Research Database (Denmark)

    Wæhrens, Brian Vejrum; Slepniov, Dmitrij

    2015-01-01

    This workbook is recommended for the attention of students of and managers in Danish small and medium sized enterprises (SMEs). Danish SMEs are currently facing a number of key challenges related to their position in global value chains. This book provides an insight into value chain management...... that may help these SMEs to occupy and sustain a competitive position in the value chain. It addresses this objective by introducing and discussing: • The concept of global value chains and its founding principles • The buyer-supplier relationships • Various SMEs operations configurations • Ideas for...

  20. Independent sets in chain cacti

    CERN Document Server

    Sedlar, Jelena

    2011-01-01

    In this paper chain cacti are considered. First, for two specific classes of chain cacti (orto-chains and meta-chains of cycles with h vertices) the recurrence relation for independence polynomial is derived. That recurrence relation is then used in deriving explicit expressions for independence number and number of maximum independent sets for such chains. Also, the recurrence relation for total number of independent sets for such graphs is derived. Finaly, the proof is provided that orto-chains and meta-chains are the only extremal chain cacti with respect to total number of independent sets (orto-chains minimal and meta-chains maximal).

  1. Fields From Markov Chains

    DEFF Research Database (Denmark)

    Justesen, Jørn

    2005-01-01

    A simple construction of two-dimensional (2-D) fields is presented. Rows and columns are outcomes of the same Markov chain. The entropy can be calculated explicitly.......A simple construction of two-dimensional (2-D) fields is presented. Rows and columns are outcomes of the same Markov chain. The entropy can be calculated explicitly....

  2. Sustainable Supply Chain Design

    DEFF Research Database (Denmark)

    Bals, Lydia; Tate, Wendy

    design for TBL sustainability. These are located in catastrophe-ridden Haiti and supported by the Germany-based investor company Yunus Social Business. Three supply chain archetypes combining physical and support chains are presented that focus on TBL sustainable outputs and outcomes. For SSCM research...

  3. Chain Reaction Polymerization.

    Science.gov (United States)

    McGrath, James E.

    1981-01-01

    The salient features and importance of chain-reaction polymerization are discussed, including such topics as the thermodynamics of polymerization, free-radical polymerization kinetics, radical polymerization processes, copolymers, and free-radical chain, anionic, cationic, coordination, and ring-opening polymerizations. (JN)

  4. Supply Chain Maturity Assessment of Coca Cola Ghana Ltd

    OpenAIRE

    Tetteh, Quaye

    2015-01-01

    This study aims to assess the supply chain process management of Coca Cola Ghana Ltd; this research is of importance due to its potential to point out processes that can yield higher performance of the supply chain and those processes that can be enhanced for higher per-formance levels. The sample for this study was selected using purposive sampling; five supply chain man-agement practitioners in the company were used for the data extraction. Questionnaires were sent to these five respond...

  5. Integrated supply chain risk management

    OpenAIRE

    Riaan Bredell; Jackie Walters

    2007-01-01

    Integrated supply chain risk management (ISCRM) has become indispensable to the theory and practice of supply chain management. The economic and political realities of the modern world require not only a different approach to supply chain management, but also bold steps to secure supply chain performance and sustainable wealth creation. Integrated supply chain risk management provides supply chain organisations with a level of insight into their supply chains yet to be achieved. If correctly ...

  6. Supply Chain Connectivity: Enhancing Participation in the Global Supply Chain

    OpenAIRE

    Patalinghug, Epictetus E.

    2015-01-01

    Supply chain connectivity is vital for the efficient flow of trade among APEC economies. This paper reviews the literature and supply chain management, describes the barriers to enhancing participation in global supply chain, analyzes the various measures of supply chain performance, and suggests steps for the Philippines to fully reap the benefits of the global value chain.

  7. Ligand pose and orientational sampling in molecular docking.

    Directory of Open Access Journals (Sweden)

    Ryan G Coleman

    Full Text Available Molecular docking remains an important tool for structure-based screening to find new ligands and chemical probes. As docking ambitions grow to include new scoring function terms, and to address ever more targets, the reliability and extendability of the orientation sampling, and the throughput of the method, become pressing. Here we explore sampling techniques that eliminate stochastic behavior in DOCK3.6, allowing us to optimize the method for regularly variable sampling of orientations. This also enabled a focused effort to optimize the code for efficiency, with a three-fold increase in the speed of the program. This, in turn, facilitated extensive testing of the method on the 102 targets, 22,805 ligands and 1,411,214 decoys of the Directory of Useful Decoys-Enhanced (DUD-E benchmarking set, at multiple levels of sampling. Encouragingly, we observe that as sampling increases from 50 to 500 to 2000 to 5000 to 20,000 molecular orientations in the binding site (and so from about 1×10(10 to 4×10(10 to 1×10(11 to 2×10(11 to 5×10(11 mean atoms scored per target, since multiple conformations are sampled per orientation, the enrichment of ligands over decoys monotonically increases for most DUD-E targets. Meanwhile, including internal electrostatics in the evaluation ligand conformational energies, and restricting aromatic hydroxyls to low energy rotamers, further improved enrichment values. Several of the strategies used here to improve the efficiency of the code are broadly applicable in the field.

  8. Understanding the supply chain

    Directory of Open Access Journals (Sweden)

    Aćimović Slobodan

    2006-01-01

    Full Text Available Supply chain management represents new business philosophy and includes strategically positioned and much wider scope of activity in comparison with its "older brother" - management of logistics. Philosophy of the concept of supply chain is directed to more coordination of key business functions of every link in distribution chain in the process of organization of the flow of both goods and information, while logistic managing instruments are focused on internal optimum of flows of goods and information within one company. Applying the concept of integrated supply chain among several companies makes the importance of operative logistics activity even greater on the level of one company, thus advancing processes of optimum and coordination within and between different companies and confirms the importance of logistics performances for the company’s profitability. Besides the fact that the borders between companies are being deleted, this concept of supply chain in one distribution channel influences increasing of importance of functional, i.e. traditional business managing approaches but instead it points out the importance of process managing approaches. Although the author is aware that "there is nothing harder, more dangerous and with uncertain success, but to find a way for introducing some novelties (Machiavelli, it would be even his additional stimulation for trying to bring closer the concept and goals of supply chain implementation that are identified in key, relevant, modern, theoretical and consulting approaches in order to achieve better understanding of the subject and faster implementation of the concept of supply chain management by domestic companies.

  9. SUMO chains: polymeric signals.

    Science.gov (United States)

    Vertegaal, Alfred C O

    2010-02-01

    Ubiquitin and ubiquitin-like proteins are conjugated to a wide variety of target proteins that play roles in all biological processes. Target proteins are conjugated to ubiquitin monomers or to ubiquitin polymers that form via all seven internal lysine residues of ubiquitin. The fate of these target proteins is controlled in a chain architecture-dependent manner. SUMO (small ubiquitin-related modifier) shares the ability of ubiquitin to form chains via internal SUMOylation sites. Interestingly, a SUMO-binding site in Ubc9 is important for SUMO chain synthesis. Similar to ubiquitin-polymer cleavage by USPs (ubiquitin-specific proteases), SUMO chain formation is reversible. SUMO polymers are cleaved by the SUMO proteases SENP6 [SUMO/sentrin/SMT3 (suppressor of mif two 3)-specific peptidase 6], SENP7 and Ulp2 (ubiquitin-like protease 2). SUMO chain-binding proteins including ZIP1, SLX5/8 (synthetic lethal of unknown function 5/8), RNF4 (RING finger protein 4) and CENP-E (centromere-associated protein E) have been identified that interact non-covalently with SUMO chains, thereby regulating target proteins that are conjugated to SUMO multimers. SUMO chains play roles in replication, in the turnover of SUMO targets by the proteasome and during mitosis and meiosis. Thus signalling via polymers is an exciting feature of the SUMO family. PMID:20074033

  10. Project Decision Chain

    DEFF Research Database (Denmark)

    Rolstadås, Asbjørn; Pinto, Jeffrey K.; Falster, Peter;

    2015-01-01

    To add value to project performance and help obtain project success, a new framework for decision making in projects is defined. It introduces the project decision chain inspired by the supply chain thinking in the manufacturing sector and uses three types of decisions: authorization, selection......, and plan decision. A primitive decision element is defined where all the three decision types can be accommodated. Each task in the primitive element can in itself contain subtasks that in turn will comprise new primitive elements. The primitive elements are nested together in a project decision chain....

  11. A novel nested multiplex polymerase chain reaction (PCR) assay for differential detection of Entamoeba histolytica, E. moshkovskii and E. dispar DNA in stool samples

    OpenAIRE

    Parija Subhash C; Khairnar Krishna

    2007-01-01

    Abstract Background E. histolytica, a pathogenic amoeba, is indistinguishable in its cyst and trophozoite stages from those of non-pathogenic E. moshkovskii and E. dispar by light microscopy. We have developed a nested multiplex PCR targeting a 16S-like rRNA gene for differential detection of all the three morphologically similar forms of E. histolytica, E. moshkovskii and E. dispar simultaneously in stool samples. Results The species specific product size for E. histolytica, E. moshkovskii a...

  12. Supply chain risk management

    Directory of Open Access Journals (Sweden)

    Christian Hollstein

    2013-03-01

    Full Text Available Background: Supply chain risk management increasingly gains prominence in many international industries. In order to strengthen supply chain structures, processes, and networks, adequate potentials for risk management need to be built (focus on effective logistics and to be utilized (focus on efficient logistics. Natural-based disasters, such as the case of Fukushima, illustrate how crucial risk management is. Method: By aligning a theoretical-conceptual framework with empirical-inductive findings, it may be hypothesized that logistical systems do have a positive effect on supply chain risk management activities.  Result/conclusion:  Flexibility and capacity, as well as redundancy and standardization, are often viewed as being conflictionary. It shows, however, that in the light of supply chain risk management, those factors may yield a common benefit if proper logistics systems are applied.  

  13. Editorial: Supply Chain Management

    Directory of Open Access Journals (Sweden)

    Aidonis, D.

    2012-01-01

    Full Text Available This special issue has followed up the 2nd Olympus International Conference on Supply Chains held on October 5-6, 2012, in Katerini, Greece. The Conference was organized by the Department of Logistics of Alexander Technological Educational Institution (ATEI of Thessaloniki, in collaboration with the Laboratory of Quantitative Analysis, Logistics and Supply Chain Management of the Department of Mechanical Engineering, Aristotle University of Thessaloniki (AUTH. During the 2-Days Conference more than 50 research papers were presented covering the following thematic areas: (i Business Logistics, (ii Transportation, Telematics and Distribution Networks, (iii Green Logistics, (iv Information and Communication Technologies in Supply Chain Management, and (v Services and Quality. Three keynote invited speakers addressed interesting issues for the Humanitarian Logistics, Green Supply Chains of the Agrifood Sector and the Opportunities and Prospects of Greek Ports chaired Round Tables with other Greek and Foreign Scientists and Specialists.

  14. Environmental Retail Supply Chains

    DEFF Research Database (Denmark)

    Kotzab, Herbert; Munch, Hilde; de Faultrier, Birgitte;

    2011-01-01

    Purpose – The purpose of this paper is to develop a scale that evaluates the environmental elements in retail supply chains and to examine the environmental supply chain management initiatives of the world's largest 100 retailing companies. Design/methodology/approach – The empirical evaluation has...... which were grouped into eight categories; they refer to “fundamental environmental attitude”, “use of energy”, “use of input material”, “product”, “packaging”, “transport”, “consumption” and “waste”. The level of environmental supply chain management can be characterised as very operational and very...... short-term oriented (green operations). Long-term oriented green design initiatives were hardly observed. Furthermore, the specific environmental activities of three retailers from Denmark, France and the UK were compared. Research limitations/implications – The empirical study investigates supply chain...

  15. Supply Chain Collaboration

    OpenAIRE

    Guy Rodrigue Ghomsi 1982

    2015-01-01

    Companies are now progressively looking beyond themselves to come up with ways to improve revenue and profit margins. This has resulted in a heightened focus on the efficiency of the supply chains. Inefficient supply chains are being perceived as cavities that can deprive the firm from its cash flows when inventory is not required and sales revenue when product is not available at the point of sales. This has stimulated development of business models that intend to leverage and enhance the su...

  16. Variance bounding Markov chains

    OpenAIRE

    Roberts, Gareth O.; Jeffrey S. Rosenthal

    2008-01-01

    We introduce a new property of Markov chains, called variance bounding. We prove that, for reversible chains at least, variance bounding is weaker than, but closely related to, geometric ergodicity. Furthermore, variance bounding is equivalent to the existence of usual central limit theorems for all L2 functionals. Also, variance bounding (unlike geometric ergodicity) is preserved under the Peskun order. We close with some applications to Metropolis–Hastings algorithms.

  17. Supply chain risk management

    OpenAIRE

    Christian Hollstein; Frank Himpel

    2013-01-01

    Background: Supply chain risk management increasingly gains prominence in many international industries. In order to strengthen supply chain structures, processes, and networks, adequate potentials for risk management need to be built (focus on effective logistics) and to be utilized (focus on efficient logistics). Natural-based disasters, such as the case of Fukushima, illustrate how crucial risk management is. Method: By aligning a theoretical-conceptual framework with empirical-induct...

  18. Editorial: Supply Chain Management

    OpenAIRE

    Aidonis, D.; Folinas, D.; Triantafillou, D.

    2012-01-01

    This special issue has followed up the 2nd Olympus International Conference on Supply Chains held on October 5-6, 2012, in Katerini, Greece. The Conference was organized by the Department of Logistics of Alexander Technological Educational Institution (ATEI) of Thessaloniki, in collaboration with the Laboratory of Quantitative Analysis, Logistics and Supply Chain Management of the Department of Mechanical Engineering, Aristotle University of Thessaloniki (AUTH). During the 2-Days Conference m...

  19. Issues on Supply Chain Management

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Although supply chain is regarded as an integrated pr ocess, actually, researchers and practitioners have primarily investigated the v arious processes of the supply chain individually. The competitive field in most markets requires well-designed integrated supply chain instead of individual o perations. In this paper, some traditional thinking of supply chain is given fir st, then SCM (Supply Chain Management) is introduced, which views the entire sup ply chain as a whole rather than individual process a...

  20. Phasic Triplet Markov Chains.

    Science.gov (United States)

    El Yazid Boudaren, Mohamed; Monfrini, Emmanuel; Pieczynski, Wojciech; Aïssani, Amar

    2014-11-01

    Hidden Markov chains have been shown to be inadequate for data modeling under some complex conditions. In this work, we address the problem of statistical modeling of phenomena involving two heterogeneous system states. Such phenomena may arise in biology or communications, among other fields. Namely, we consider that a sequence of meaningful words is to be searched within a whole observation that also contains arbitrary one-by-one symbols. Moreover, a word may be interrupted at some site to be carried on later. Applying plain hidden Markov chains to such data, while ignoring their specificity, yields unsatisfactory results. The Phasic triplet Markov chain, proposed in this paper, overcomes this difficulty by means of an auxiliary underlying process in accordance with the triplet Markov chains theory. Related Bayesian restoration techniques and parameters estimation procedures according to the new model are then described. Finally, to assess the performance of the proposed model against the conventional hidden Markov chain model, experiments are conducted on synthetic and real data. PMID:26353069

  1. Comparison of human cytomegalovirus DNA detection in different samples by fluorescent quantitative polymerase chain reaction%人巨细胞病毒感染的核酸检测比较及对肝脏损伤的研究

    Institute of Scientific and Technical Information of China (English)

    刘春梅; 邹建文; 刘玲玲; 鞠瑛; 栾芳; 田文君; 王盛华; 刘义庆; 张炳昌

    2014-01-01

    Objective To investigate the diagnostic value of fluorescent quantitative polymerase chain re-action ( FQ-PCR) technique in detecting the human cytomegalovirus infection and its impact on hepatic function through the detection of human cytomegalovirus (HCMV) DNA in urinary epithelial cell (EC), blood of breast-feeding infants and the milk of their mothers .Methods FQ-PCR was used to analyze the HCMV DNA in urinary EC, blood of 104 breast-fed suspected infants and breast milk of their mothers .The hepatic impairment was ana-lyzed through detecting aspartate aminotransferase ( AST ) , alanine aminotransferase ( ALT ) , gamma glutamyl transpeptidase ( GGT ) and total bilirubin .Results The positive rate of urinary EC and blood was 52.9%(55/104) and 24.0% (25/104) respectively.The positive rate of urinary EC was much higher than that of blood.The differences between these groups were statistically significant (P<0.01).The positive rate of breast milk was 81.7%(85/104), and the positive rate of the paired urinary EC and/or blood in positive breast milk test was 62.4%(53/85).The difference between the two groups was statistically significant (P<0.05).The possibility of hepatic impairment was much higher with the HCMV DNA copies in infants .Conclusions Detection of HCMV DNA load in urinary EC by FQ-PCR can predict HCMV active infection in infants and monitor the treat-ment of HCMV infection .The level of AST , ALT, GGT and total bilirubin can be used for evaluating hepatic im-pairment .%目的:应用实时荧光定量聚合酶链反应( FQ-PCR)检测疑似人巨细胞病毒( HCMV)感染的患儿尿液、血液及对应母亲乳汁中HCMV DNA含量,探讨其在HCMV感染诊断中的价值及对肝脏损伤情况。方法应用FQ-PCR方法检测104例疑似HCMV感染患儿新鲜尿液上皮细胞、血液及其对应的母亲乳汁中的HCMV DNA拷贝数,并同时检测患儿血液中天冬氨酸转氨酶( AST)、丙氨酸转氨酶( ALT)、谷氨酰

  2. Supply chain quality management

    Directory of Open Access Journals (Sweden)

    Hannan Amoozad Mahdiraji

    2012-10-01

    Full Text Available In recent years, there are several methods introduced for the improvement of operational performances. Total quality management and supply chain management are two methods recommended for this purpose. These two approaches have been studied in most researches separately, while they have objectives in common, and this makes them a strategic means, which can be used, simultaneously. Total quality management and supply chain management play significant roles to increase the organizational competitiveness power. Moreover, they have only one purpose that is customer satisfaction, and they are different only on their approaches to reach their objectives. In this research, we aim to study both approaches of quality management and supply chain, their positive increasing effects that may be generated after their integration. For this purpose, the concept and definitions of each approach is studied, independently, their similarities and differences are recognized, and finally, the advantages of their integration are introduced.

  3. Bayesian Posterior Distributions Without Markov Chains

    OpenAIRE

    Cole, Stephen R.; Chu, Haitao; Greenland, Sander; Hamra, Ghassan; Richardson, David B.

    2012-01-01

    Bayesian posterior parameter distributions are often simulated using Markov chain Monte Carlo (MCMC) methods. However, MCMC methods are not always necessary and do not help the uninitiated understand Bayesian inference. As a bridge to understanding Bayesian inference, the authors illustrate a transparent rejection sampling method. In example 1, they illustrate rejection sampling using 36 cases and 198 controls from a case-control study (1976–1983) assessing the relation between residential ex...

  4. Essentials of supply chain management

    CERN Document Server

    Hugos, Michael H

    2011-01-01

    The latest thinking, strategies, developments, and technologies to stay current in supply chain management Presenting the core concepts and techniques of supply chain management in a clear, concise and easily readable style, the Third Edition of Essentials of Supply Chain Management outlines the most crucial tenets and concepts of supply chain management.

  5. Building the resilient supply chain.

    OpenAIRE

    Christopher, Martin; Peck, Helen

    2004-01-01

    In today’s uncertain and turbulent markets, supply chain vulnerability has become an issue of significance for many companies. As supply chains become more complex as a result of global sourcing and the continued trend to ‘leaning-down’, supply chain risk increases. The challenge to business today is to manage and mitigate that risk through creating more resilient supply chains.

  6. Supply-Chain Optimization Template

    Science.gov (United States)

    Quiett, William F.; Sealing, Scott L.

    2009-01-01

    The Supply-Chain Optimization Template (SCOT) is an instructional guide for identifying, evaluating, and optimizing (including re-engineering) aerospace- oriented supply chains. The SCOT was derived from the Supply Chain Council s Supply-Chain Operations Reference (SCC SCOR) Model, which is more generic and more oriented toward achieving a competitive advantage in business.

  7. Fuzzy Markov chains: uncertain probabilities

    OpenAIRE

    James J. Buckley; Eslami, Esfandiar

    2002-01-01

    We consider finite Markov chains where there are uncertainties in some of the transition probabilities. These uncertainties are modeled by fuzzy numbers. Using a restricted fuzzy matrix multiplication we investigate the properties of regular, and absorbing, fuzzy Markov chains and show that the basic properties of these classical Markov chains generalize to fuzzy Markov chains.

  8. Integrated supply chain risk management

    Directory of Open Access Journals (Sweden)

    Riaan Bredell

    2007-11-01

    Full Text Available Integrated supply chain risk management (ISCRM has become indispensable to the theory and practice of supply chain management. The economic and political realities of the modern world require not only a different approach to supply chain management, but also bold steps to secure supply chain performance and sustainable wealth creation. Integrated supply chain risk management provides supply chain organisations with a level of insight into their supply chains yet to be achieved. If correctly applied, this process may optimise management decision-making and assist in the protection and enhancement of shareholder value.

  9. Plastic value chains

    DEFF Research Database (Denmark)

    Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin;

    2014-01-01

    Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example...

  10. Innovation in Supply Chains

    DEFF Research Database (Denmark)

    Maier, Maximilian; Korbel, Jakob; Brem, Alexander

    2015-01-01

    . Moreover, along with the fourth industrial revolution – industry 4.0 – new technologies such as cyber physical systems are fast gaining popularity. Hence, based on the analysis of relevant literature, we further develop the supply chain committee model, developed by Kaluza et al. (2003) to demonstrate how...

  11. Heavy chain only antibodies

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moein; Rahbarizadeh, Fatemeh; Ahmadvand, Davoud;

    2013-01-01

    Unlike conventional antibodies, heavy chain only antibodies derived from camel contain a single variable domain (VHH) and two constant domains (CH2 and CH3). Cloned and isolated VHHs possess unique properties that enable them to excel conventional therapeutic antibodies and their smaller antigen...

  12. METRODOS: Meteorological preprocessor chain

    DEFF Research Database (Denmark)

    Astrup, P.; Mikkelsen, T.; Deme, S.

    2001-01-01

    - heat flux related measurement, e.g. a temperature gradient, are used to give local values of friction velocity and Monin-Obukhov length plus an estimate of the mixing height. The METRODOS meteorological preprocessor chain is an integral part of the RODOS - Real Time On Line Decision Support - program...

  13. Supply chain reliability modelling

    Directory of Open Access Journals (Sweden)

    Eugen Zaitsev

    2012-03-01

    Full Text Available Background: Today it is virtually impossible to operate alone on the international level in the logistics business. This promotes the establishment and development of new integrated business entities - logistic operators. However, such cooperation within a supply chain creates also many problems related to the supply chain reliability as well as the optimization of the supplies planning. The aim of this paper was to develop and formulate the mathematical model and algorithms to find the optimum plan of supplies by using economic criterion and the model for the probability evaluating of non-failure operation of supply chain. Methods: The mathematical model and algorithms to find the optimum plan of supplies were developed and formulated by using economic criterion and the model for the probability evaluating of non-failure operation of supply chain. Results and conclusions: The problem of ensuring failure-free performance of goods supply channel analyzed in the paper is characteristic of distributed network systems that make active use of business process outsourcing technologies. The complex planning problem occurring in such systems that requires taking into account the consumer's requirements for failure-free performance in terms of supply volumes and correctness can be reduced to a relatively simple linear programming problem through logical analysis of the structures. The sequence of the operations, which should be taken into account during the process of the supply planning with the supplier's functional reliability, was presented.

  14. Shared Value Chain Design

    DEFF Research Database (Denmark)

    Bals, Lydia; Tate, Wendy L.

    In Sustainable Supply Chain Management (SSCM) research still the classic economic perspective is the dominating perspective, although the triple bottom line (including economic, social and ecological) is well accepted. The theoretical foundation for the paper is Stakeholder Theory. Case studies o...

  15. Exploration Supply Chain Simulation

    Science.gov (United States)

    2008-01-01

    The Exploration Supply Chain Simulation project was chartered by the NASA Exploration Systems Mission Directorate to develop a software tool, with proper data, to quantitatively analyze supply chains for future program planning. This tool is a discrete-event simulation that uses the basic supply chain concepts of planning, sourcing, making, delivering, and returning. This supply chain perspective is combined with other discrete or continuous simulation factors. Discrete resource events (such as launch or delivery reviews) are represented as organizational functional units. Continuous resources (such as civil service or contractor program functions) are defined as enabling functional units. Concepts of fixed and variable costs are included in the model to allow the discrete events to interact with cost calculations. The definition file is intrinsic to the model, but a blank start can be initiated at any time. The current definition file is an Orion Ares I crew launch vehicle. Parameters stretch from Kennedy Space Center across and into other program entities (Michaud Assembly Facility, Aliant Techsystems, Stennis Space Center, Johnson Space Center, etc.) though these will only gain detail as the file continues to evolve. The Orion Ares I file definition in the tool continues to evolve, and analysis from this tool is expected in 2008. This is the first application of such business-driven modeling to a NASA/government-- aerospace contractor endeavor.

  16. CHAINE DES ROTISSEUR @ HILTON

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The annual gala dinner of Chaine des Rotisseurs was hosted by Hilton Beijing. The “Ballet Dinner” - a great creation for both art and fine dining lovers was taken place in varies places within the hotel, including hotel lobby, 3rd floor and lobby lounge.

  17. Sampling methods

    OpenAIRE

    Kılıç, Selim

    2013-01-01

    Most of the studies related to health are conducted with samples. Selection of sampling may be performed with random or nonrandom sampling methods. Sampling methods may vary with respect to some characteristics of study population, researchers’ aims and facilities. It is necessary to select samples by random sampling methods in order to provide the representativeness of the study population. The advantages and disadvantages of different sampling methods are presented in this manuscript which ...

  18. A protrusion can "eclipse" looping of a long self-avoiding chain

    CERN Document Server

    Pollak, Yaroslav; Amit, Roee

    2016-01-01

    We simulate long self-avoiding chains using a weighted-biased sampling Monte-Carlo algorithm, and compute the probabilities for chain looping with and without a protrusion. We find that a protrusion near one of the chain's termini reduces the probability of looping, even for chains much longer than the protrusion-chain-terminus distance. This effect increases with protrusion size, and decreases with protrusion-terminus distance. We model the simulated results theoretically by considering how the protrusion "eclipses" the chain terminus closer to the protrusion from the more distant chain terminus. This eclipse mechanism has implications for understanding the regulatory role of proteins bound to DNA.

  19. Boat sampling

    International Nuclear Information System (INIS)

    This presentation describes essential boat sampling activities: on site boat sampling process optimization and qualification; boat sampling of base material (beltline region); boat sampling of weld material (weld No. 4); problems accompanied with weld crown varieties, RPV shell inner radius tolerance, local corrosion pitting and water clarity. The equipment used for boat sampling is described too. 7 pictures

  20. Performance Metrics in Supply Chain Management. Evidence from Romanian Economy

    Directory of Open Access Journals (Sweden)

    Alexandru Constăngioară

    2013-02-01

    Full Text Available The proposed empirical research uses a national sample of 19 Romanian companies from various industries to estimate de utilities for financial and non-financial performance measures used in Romanian supply chains. Empirical findings show that national supply chain measurement systems are balanced, using both financial and non-financial performance measures. The high estimated utility corresponding to indicators measuring logistic costs provides evidence that inter-functional and inter-organization integration in supply chains at national level are realized through operational excellence. Achieving the full potential of supply chain integration requires that management fosters both integration of operations and integration of customers.

  1. A conceptual framework to analyse supply chain designs

    Directory of Open Access Journals (Sweden)

    J. A. Badenhorst-Weiss

    2011-12-01

    Full Text Available Objectives: Supply chain design (SCD is a concept that forms an integral part of supply chain management (SCM. Effective SCD enhances supply chain integration (SCI which in turn contributes towards improved supply chain performance. Therefore, organisations' supply chain designs need to be analysed. This article proposes a conceptual framework to analyse organisations' supply chain designs. The objective of this article is to determine whether the proposed conceptual framework is a workable instrument with which organisations can analyse their supply chain designs. Problem investigated: Effective SCD is a complex and demanding undertaking and has become a major challenge for organisations. Moreover, the literature suggests that organisations allow their supply chains to evolve rather than consciously designing them. Although the importance of SCD is emphasised, very little attention is given to what it entails exactly. The problem statement of this article is thus: What are the elements of SCD and how can these elements be included in a conceptual framework to analyse organisations' supply chain designs? Methodology: The methodology used in this article comprised two phases. Firstly, a literature review was conducted to identify SCD elements. The elements were used to develop a conceptual framework with which organisations can analyse their supply chain designs. Secondly, the conceptual framework was tested in 13 organisations to determine whether it is a workable instrument to analyse supply chain designs. The respondents were selected by means of non-probability sampling. Purposive, judgmental and convenience sampling methods were used to select the sample. Findings and implications: As mentioned, the conceptual framework was tested empirically within 13 organisations. The findings show that the conceptual framework is in fact a workable instrument to analyse supply chain designs. Value of the research: The research will make a contribution in

  2. Effect of gamma radiation on the growth of Aspergillus Flavus aflatoxins producer and on the use of polymerase chain reaction technique (PCR) in samples of maize grains artificially inoculated; Efeitos da radiacao gama no crescimento de Aspergillus flavus produtor de aflatoxinas e no emprego da tecnica da Reacao em Cadeia da Polimerase (RCP) em amostras de graos de milho inoculadas artificialmente

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Simone

    2003-07-01

    The aim of this present study was to verify the effects of gamma radiation on the growth of Aspergillus flavus Link aflatoxins producer; to demonstrate the application of Polymerase Chain Reaction (PCR) technique in the diagnostic of A. Flavus, as well to verify the effect of radiation in the profile of DNA bands. Twenty samples of grains maize with 200 g each were individually irradiated with 20 kGy, to eliminate the microbial contamination. In following, the samples were inoculated with an toxigenic A. flavus (1x10{sup 6} spores/ml), incubated for 15 days at 25 deg C with a relative humidity of around 97,5% and irradiated with 0, 2; 5 and 10 kGy. The samples, 5 to each dose of irradiation, were individually analyzed for the number of fungal cells, water activity, viability test (fluorescein diacetate and ethidium bromide), PCR and aflatoxins (AFB) detection. The results showed that the doses used were effective in reducing the number of Colony Forming Units (CFU/g) mainly the doses of 5 and 10 kGy. In addition, the viability test showed a decrease of viable cells with increase of irradiation doses. The reduction of AFB{sub 1} and AFB-2, was more efficient with the use of 2 kGy in comparison with the dose of 5 kGy, while the dose of 10 kGy, degraded the aflatoxins. Thereby, it was observed that AFB2 showed to be more radiosensitive. The use of PCR technique showed the presence of DNA bands, in all samples. (author)

  3. Innovation Across the Supply Chain

    DEFF Research Database (Denmark)

    Druehl, Cheryl; Carrillo, Janice; Hsuan, Juliana

    Innovation is an integral part of every firm’s ongoing operations. Beyond product innovation, supply chain innovations offer a unique source of competitive advantage. We synthesize recent research on innovation in the supply chain, specifically, innovative supply chain processes such as collabora...... collaborations with customers and suppliers to create new product and process innovations, open innovation, and globally distributed innovation. We conclude with potential areas for future research.......Innovation is an integral part of every firm’s ongoing operations. Beyond product innovation, supply chain innovations offer a unique source of competitive advantage. We synthesize recent research on innovation in the supply chain, specifically, innovative supply chain processes such as...

  4. Decision-Making for Supply Chain Integration Supply Chain Integration

    CERN Document Server

    Lettice, Fiona; Durowoju, Olatunde

    2012-01-01

    Effective supply chain integration, and the tight co-ordination it creates, is an essential pre-requisite for successful supply chain management.  Decision-Making for Supply Chain Integration is a practical reference on recent research in the area of supply chain integration focusing on distributed decision-making problems. Recent applications of various decision-making tools for integrating supply chains are covered including chapters focusing on: •Supplier selection, pricing strategy and inventory decisions in multi-level supply chains, •RFID-enabled distributed decision-making, •Operational risk issues and time-critical decision-making for sensitive logistics nodes, Modelling end to end processes to improve supply chain integration, and •Integrated systems to improve service delivery and optimize resource use. Decision-Making for Supply Chain Integration provides an insight into the tools and methodologies of this field with support from real-life case studies demonstrating successful application ...

  5. Iron modulates the alpha chain of fibrinogen.

    Science.gov (United States)

    Nielsen, Vance G; Jacobsen, Wayne K

    2016-04-01

    Iron-bound fibrinogen has been noted to accelerate plasmatic coagulation in patients with divergent conditions involving upregulation of heme oxygenase activity, including hemodialysis, Alzheimer's disease, sickle cell anemia, and chronic migraine. Our goal was to determine if a site of iron-fibrinogen interaction was on the alpha chain. Using thrombelastography, we compared the coagulation kinetic profiles of plasma exposed to 0-10 µM ferric chloride after activation of coagulation with thrombin generated by contact activation of plasma with the plastic sample cup or by exposure to 1 µg/ml of Calloselasma rhodostoma venom (rich in ancrod activity), which causes coagulation via polymerization of alpha chain monomers. Venom mediated coagulation always occurred before thrombin activated thrombus formation, and ferric chloride always diminished the time of onset of coagulation and increased the velocity of clot growth. Iron enhances plasmatic coagulation kinetics by modulating the alpha chain of fibrinogen. PMID:26782808

  6. On the Markov Chain Monte Carlo (MCMC) method

    Indian Academy of Sciences (India)

    Rajeeva L Karandikar

    2006-04-01

    Markov Chain Monte Carlo (MCMC) is a popular method used to generate samples from arbitrary distributions, which may be specified indirectly. In this article, we give an introduction to this method along with some examples.

  7. Volumes of chain links

    CERN Document Server

    Kaiser, James; Rollins, Clint

    2011-01-01

    Agol has conjectured that minimally twisted n-chain links are the smallest volume hyperbolic manifolds with n cusps, for n at most 10. In his thesis, Venzke mentions that these cannot be smallest volume for n at least 11, but does not provide a proof. In this paper, we give a proof of Venzke's statement. The proof for n at least 60 is completely rigorous. The proof for n between 11 and 59 uses a computer calculation, and can be made rigorous for manifolds of small enough complexity, using methods of Moser and Milley. Finally, we prove that the n-chain link with 2m or 2m+1 half-twists cannot be the minimal volume hyperbolic manifold with n cusps, provided n is at least 60 or |m| is at least 8, and we give computational data indicating this remains true for smaller n and |m|.

  8. Towards Intelligent Supply Chains

    DEFF Research Database (Denmark)

    Siurdyban, Artur; Møller, Charles

    2012-01-01

    applied to the context of organizational processes can increase the success rate of business operations. The framework is created using a set of theoretical based constructs grounded in a discussion across several streams of research including psychology, pedagogy, artificial intelligence, learning...... of deploying inapt operations leading to deterioration of profits. To address this problem, we propose a unified business process design framework based on the paradigm of intelligence. Intelligence allows humans and human-designed systems cope with environmental volatility, and we argue that its principles......, business process management and supply chain management. It outlines a number of system tasks combined in four integrated management perspectives: build, execute, grow and innovate, put forward as business process design propositions for Intelligent Supply Chains....

  9. Extended linear chain compounds

    CERN Document Server

    Linear chain substances span a large cross section of contemporary chemistry ranging from covalent polymers, to organic charge transfer com­ plexes to nonstoichiometric transition metal coordination complexes. Their commonality, which coalesced intense interest in the theoretical and exper­ imental solid state physics/chemistry communities, was based on the obser­ vation that these inorganic and organic polymeric substrates exhibit striking metal-like electrical and optical properties. Exploitation and extension of these systems has led to the systematic study of both the chemistry and physics of highly and poorly conducting linear chain substances. To gain a salient understanding of these complex materials rich in anomalous aniso­ tropic electrical, optical, magnetic, and mechanical properties, the conver­ gence of diverse skills and talents was required. The constructive blending of traditionally segregated disciplines such as synthetic and physical organic, inorganic, and polymer chemistry, crystallog...

  10. Demand chain management-integrating marketing and supply chain management

    OpenAIRE

    Jüttner, Uta; Christopher, Martin; Baker, Susan

    2007-01-01

    This paper endorses demand chain management as a new business model aimed at creating value in today's marketplace, and combining the strengths of marketing and supply chain competencies. Demand chain design is based on a thorough market understanding and has to be managed in such a way as to effectively meet differing customer needs. Based on a literature review as well as the findings from a co-development workshop and focus group discussions with marketing and supply chain professionals, a...

  11. Putting Markov Chains Back into Markov Chain Monte Carlo

    OpenAIRE

    Barker, Richard J.; Schofield, Matthew R.

    2007-01-01

    Markov chain theory plays an important role in statistical inference both in the formulation of models for data and in the construction of efficient algorithms for inference. The use of Markov chains in modeling data has a long history, however the use of Markov chain theory in developing algorithms for statistical inference has only become popular recently. Using mark-recapture models as an illustration, we show how Markov chains can be used for developing demographic models and also ...

  12. Supply Chain Initiatives Database

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-11-01

    The Supply Chain Initiatives Database (SCID) presents innovative approaches to engaging industrial suppliers in efforts to save energy, increase productivity and improve environmental performance. This comprehensive and freely-accessible database was developed by the Institute for Industrial Productivity (IIP). IIP acknowledges Ecofys for their valuable contributions. The database contains case studies searchable according to the types of activities buyers are undertaking to motivate suppliers, target sector, organization leading the initiative, and program or partnership linkages.

  13. Input chains and industrialization

    OpenAIRE

    Ciccone, Antonio

    2000-01-01

    A key aspect of industrialization is the adoption of increasing-returns-to-scale, industrial, technologies. Two other, well-documented aspects are that industrial technologies are adopted throughout intermediate-input chains and that they use intermediate inputs intensively relative to the technologies they replace. These features of industrial technologies combined imply that countries with access to similar technologies may have very different levels of industrial...

  14. Polymerase chain reaction

    OpenAIRE

    Gaurav Solanki

    2015-01-01

    The polymerase chain reaction (PCR) is a technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence. PCR is now a common and often indispensable technique used in medical and biological research labs for a variety of applications. There are three major steps involved in the PCR technique: denaturation, annealing and extension. PCR is useful in the investigation...

  15. Tax efficient supply chain

    OpenAIRE

    Borralho, Joana Patrícia Costeira

    2014-01-01

    Master of Science in Business Administration. This case started with the following question: How supply chains and tax policy interact? This question was the starting point for this study and was developed under the areas of Logistics and International Tax Policy. In order to support this study, the adopted methodology was the selection of a Multinational company – LPR Portugal – which has the transportation and distribution in the European Union as a scope of service and...

  16. Inclusive Global Value Chains

    OpenAIRE

    Cusolito, Ana Paula; Safadi, Raed; Taglioni, Daria

    2016-01-01

    This report's focus is making global value chains (GVCs) more inclusive. To achieve inclusiveness is by overcoming participation constraints for Small and Medium Enterprises (SMEs) and facilitation access for Low Income Developing Countries (LIDCs). The underlying assumption is that most firms in LIDCs are SMEs. Even larger firms in LIDCs are likely to face similar challenges to SMEs, including a less supportive domestic operating environment and weaker institutions that lead to higher fixed ...

  17. Structural Origins of Nitroxide Side Chain Dynamics on Membrane Protein [alpha]-Helical Sites

    Energy Technology Data Exchange (ETDEWEB)

    Kroncke, Brett M.; Horanyi, Peter S.; Columbus, Linda (UV)

    2010-12-07

    Understanding the structure and dynamics of membrane proteins in their native, hydrophobic environment is important to understanding how these proteins function. EPR spectroscopy in combination with site-directed spin labeling (SDSL) can measure dynamics and structure of membrane proteins in their native lipid environment; however, until now the dynamics measured have been qualitative due to limited knowledge of the nitroxide spin label's intramolecular motion in the hydrophobic environment. Although several studies have elucidated the structural origins of EPR line shapes of water-soluble proteins, EPR spectra of nitroxide spin-labeled proteins in detergents or lipids have characteristic differences from their water-soluble counterparts, suggesting significant differences in the underlying molecular motion of the spin label between the two environments. To elucidate these differences, membrane-exposed {alpha}-helical sites of the leucine transporter, LeuT, from Aquifex aeolicus, were investigated using X-ray crystallography, mutational analysis, nitroxide side chain derivatives, and spectral simulations in order to obtain a motional model of the nitroxide. For each crystal structure, the nitroxide ring of a disulfide-linked spin label side chain (R1) is resolved and makes contacts with hydrophobic residues on the protein surface. The spin label at site I204 on LeuT makes a nontraditional hydrogen bond with the ortho-hydrogen on its nearest neighbor F208, whereas the spin label at site F177 makes multiple van der Waals contacts with a hydrophobic pocket formed with an adjacent helix. These results coupled with the spectral effect of mutating the i {+-} 3, 4 residues suggest that the spin label has a greater affinity for its local protein environment in the low dielectric than on a water-soluble protein surface. The simulations of the EPR spectra presented here suggest the spin label oscillates about the terminal bond nearest the ring while maintaining weak

  18. Tryptophan rotamer distributions in amphipathic peptides at a lipid surface.

    OpenAIRE

    Clayton, A H; Sawyer, W. H.

    1999-01-01

    The fluorescence decay of tryptophan is a sensitive indicator of its local environment within a peptide or protein. We describe the use of frequency domain fluorescence spectroscopy to determine the conformational and environmental changes associated with the interaction of single tryptophan amphipathic peptides with a phospholipid surface. The five 18-residue peptides studied are based on a class A amphipathic peptide known to associate with lipid bilayers. The peptides contain a single tryp...

  19. Supply chain dynamics in Asia

    OpenAIRE

    Banomyong, Ruth

    2010-01-01

    Supply chain management in Asia is a relatively novel topic but a key challenge for all Asian based manufacturers and traders when trying to integrate into the "global market". The purpose of the paper is to describe key supply chain issues faced in Asia. These issues are related to supply chain security that forces Asian firms to comply with numerous requirements as well as the importance of a properly managed supply chain in enhancing firms' competitiveness. The critical role played by Asia...

  20. Requirements of supply chain management in differentiating European pork chains.

    Science.gov (United States)

    Trienekens, Jacques; Wognum, Nel

    2013-11-01

    This paper summarizes results obtained by research into pork chain management in the EU Integrated Project Q-Porkchains. Changing demands for intrinsic and extrinsic quality attributes of pork products impact the way supply chain management should be organized from the farmer down to the consumer. The paper shows the importance of Quality Management Systems for integrating supply chains and enhancing consumer confidence. The paper also presents innovations in information system integration for aligning information exchange in the supply chain and logistics concepts based on innovative measurement technologies at the slaughterhouse stage. In the final section research challenges towards sustainable pork supply chains satisfying current consumer demands are presented. PMID:23611335

  1. Academic Education Chain Operation Model

    OpenAIRE

    Ruskov, Petko; Ruskov, Andrey

    2007-01-01

    This paper presents an approach for modelling the educational processes as a value added chain. It is an attempt to use a business approach to interpret and compile existing business and educational processes towards reference models and suggest an Academic Education Chain Operation Model. The model can be used to develop an Academic Chain Operation Reference Model.

  2. Designing structural supply chain flexibility

    NARCIS (Netherlands)

    Mulinski, Ksawery Jan

    2012-01-01

    In a continuously changing business environment the role of supply chain flexibility is constantly increasing. A flexible supply chain can ensure survival in quickly changing market conditions as well as enable sustainable growth. This thesis explores the topic of supply chain flexibility with focus

  3. Risk Management in Logystics Chains

    OpenAIRE

    Butrin, Andrey; Vikulov, Vladimir

    2013-01-01

    Article is devoted to risk management of supply chain. The authors considered indicators of supply chain risks, including risks caused by supplier. Authors formed a method of optimizing the level of supply chain risk in the integration with suppliers and customers.

  4. On chains of centered valuations

    Directory of Open Access Journals (Sweden)

    Rachid Chibloun

    2003-01-01

    Full Text Available We study chains of centered valuations of a domain A and chains of centered valuations of A [X1,…,Xn] corresponding to valuations of A. Finally, we make some applications to chains of valuations centered on the same ideal of A [X1,…,Xn] and extending the same valuation of A.

  5. Concurrent Product & Supply Chain Creation

    DEFF Research Database (Denmark)

    Gubi, Ebbe

    that product and supply chains should be created concurrently and integrated. The concept of Concurrent Product & Supply Chain Creation is introduced, and the two main components Focused Supply Chains and Design For Logistics are explained and exemplified by use of Bang & Olufsen....

  6. Radiology's value chain.

    Science.gov (United States)

    Enzmann, Dieter R

    2012-04-01

    A diagnostic radiology value chain is constructed to define its main components, all of which are vulnerable to change, because digitization has caused disaggregation of the chain. Some components afford opportunities to improve productivity, some add value, while some face outsourcing to lower labor cost and to information technology substitutes, raising commoditization risks. Digital image information, because it can be competitive at smaller economies of scale, allows faster, differential rates of technological innovation of components, initiating a centralization-to-decentralization technology trend. Digitization, having triggered disaggregation of radiology's professional service model, may soon usher in an information business model. This means moving from a mind-set of "reading images" to an orientation of creating and organizing information for greater accuracy, faster speed, and lower cost in medical decision making. Information businesses view value chain investments differently than do small professional services. In the former model, producing a better business product will extend image interpretation beyond a radiologist's personal fund of knowledge to encompass expanding external imaging databases. A follow-on expansion with integration of image and molecular information into a report will offer new value in medical decision making. Improved interpretation plus new integration will enrich and diversify radiology's key service products, the report and consultation. A more robust, information-rich report derived from a "systems" and "computational" radiology approach will be facilitated by a transition from a professional service to an information business. Under health care reform, radiology will transition its emphasis from volume to greater value. Radiology's future brightens with the adoption of a philosophy of offering information rather than "reads" for decision making. Staunchly defending the status quo via turf wars is unlikely to constitute a

  7. India China Supply Chain

    OpenAIRE

    Danendran, Rahul

    2014-01-01

    This research report addresses the topic of India China supply chain. This study would be looking at the existing policies among the China India trade and a real life scenario of this trade will be analysed. By conducting this study, the current situation of trades can be put forward and it will give an idea to what extent trade policies are useful when it comes to trading and to what extent the policies aid the bottlenecks faced by a trader. The objectives of the research are to understa...

  8. Secondary Heavy Chain Rearrangement

    OpenAIRE

    Sekiguchi, Debora R.; Eisenberg, Robert A.; Weigert, Martin

    2003-01-01

    The chronic graft-versus-host (cGVH) reaction results in a syndrome that closely resembles systemic lupus erythematosus (SLE). It is induced in nonautoimmune mice by the transfer of alloreactive T cells. The availability of anti-DNA transgenes allows us to study the genetic origins of autoantibodies in this model. We induced cGVH in two anti-DNA H chain site-directed transgenic mouse strains. This resulted in clonal expansion and selection of specific mutations in the anti–double-stranded (ds...

  9. A chain of FPU cells

    OpenAIRE

    Verhulst, F.

    2015-01-01

    In contrast to the classical Fermi-Pasta-Ulam (FPU) chain, the inhomogeneous FPU chain shows nearly all the principal resonances. Using this fact, we can construct a periodic FPU chain of low dimension, for instance a FPU cell of four degrees-of-freedom, that can be used as a building block for a chain of FPU cells. Differences between chains in nearest-neighbour interaction and those in overall interaction are caused by symmetry. We will also show some results on the dynamics of a particular...

  10. Green supply chain management practices and performance

    OpenAIRE

    Laosirihongthong, Tritos; Adebanjo, Dotun; Tan, Keah Choon

    2013-01-01

    Purpose – The purpose of this study is to examine the deployment of pro-active and re-active practices in the implementation of green supply chain management (GSCM) and analyze their impact on environmental, economic, and intangible performance by considering business strategy as organizational focus. Design/methodology/approach – Data were collected from a sample of 190 ISO 14001 certified manufacturing companies in Thailand and used to test the research hypotheses. Factor analysis was ...

  11. RESEARCH SAMPLING

    OpenAIRE

    NISHA MD

    2012-01-01

    No aspect of the research plan is more critical for assuring the usefulness of a study than the sampling strategy. It will determine if the results of the study can be applied as evidence and contributes to the trustworthiness of the results. The sampling strategy is a critical part of research design. An appropriate sampling plan is vital for drawing the right conclusions from a study. Good sampling is critical for the confident application of the study findings to other people, settings, or...

  12. Doping of Semiconducting Atomic Chains

    Science.gov (United States)

    Toshishige, Yamada; Kutler, Paul (Technical Monitor)

    1997-01-01

    Due to the rapid progress in atom manipulation technology, atomic chain electronics would not be a dream, where foreign atoms are placed on a substrate to form a chain, and its electronic properties are designed by controlling the lattice constant d. It has been shown theoretically that a Si atomic chain is metallic regardless of d and that a Mg atomic chain is semiconducting or insulating with a band gap modified with d. For electronic applications, it is essential to establish a method to dope a semiconducting chain, which is to control the Fermi energy position without altering the original band structure. If we replace some of the chain atoms with dopant atoms randomly, the electrons will see random potential along the chain and will be localized strongly in space (Anderson localization). However, if we replace periodically, although the electrons can spread over the chain, there will generally appear new bands and band gaps reflecting the new periodicity of dopant atoms. This will change the original band structure significantly. In order to overcome this dilemma, we may place a dopant atom beside the chain at every N lattice periods (N > 1). Because of the periodic arrangement of dopant atoms, we can avoid the unwanted Anderson localization. Moreover, since the dopant atoms do not constitute the chain, the overlap interaction between them is minimized, and the band structure modification can be made smallest. Some tight-binding results will be discussed to demonstrate the present idea.

  13. Spin chains and combinatorics

    International Nuclear Information System (INIS)

    In this paper we continue the investigation of finite XXZ spin chains with periodic boundary conditions and odd number of sites, initiated in our previous article (Stroganov Yu. G. 2001 J. Phys. A: Math. Gen. 34 L179-85). As it turned out, for a special value of the asymmetry parameter Δ=-1/2 the Hamiltonian of the system has an eigenvalue, which is exactly proportional to the number of sites E=-3N/2. Using Mathematica we have found explicitly the corresponding eigenvectors for N≤17. The obtained results support the conjecture our paper that this special eigenvalue corresponds to the ground state vector. We make a lot of conjectures concerning the correlations of the model. Many remarkable relations between the wavefunction components are noted. It turns out, for example, that the ratio of the largest component to the least one is equal to the number of the alternating sign matrices. (author)

  14. Supply chain reaction

    International Nuclear Information System (INIS)

    'Logic' (Leading Oil and Gas Industry Competitiveness) is a government-industry supply chain management initiative which aims to improve the competitiveness of the UK's North Sea business by 1 billion UK pounds by 2002 and its export performance by 50% inside 5 years. Much of the article is devoted to the background and views of Logic's chief executive Chris. Freeman. Freeman makes clear that 'unlike Crine, we are not a cost-reduction initiative: that may be one of the outcomes, but we are really focusing on the co-operation side of things'. Logic aims to change the culture of the UK offshore industry through example. Freeman believes that the creation of collaborative success will flag up industry and give credence to Logics objectives

  15. Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Gaurav Solanki

    2012-10-01

    Full Text Available The polymerase chain reaction (PCR is a technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence. PCR is now a common and often indispensable technique used in medical and biological research labs for a variety of applications. There are three major steps involved in the PCR technique: denaturation, annealing and extension. PCR is useful in the investigation and diagnosis of a growing number of diseases. PCR is also used in forensics laboratories. PCR can identify genes that have been implicated in the development of cancer. The present paper is an attempt to review basics of PCR in relation to its methods, application and use.

  16. Chain formation of metal atoms

    DEFF Research Database (Denmark)

    Bahn, Sune Rastad; Jacobsen, Karsten Wedel

    2001-01-01

    The possibility of formation of single-atomic chains by manipulation of nanocontacts is studied for a selection of metals (Ni, Pd, Pt, Cu, Ag, Au). Molecular dynamics simulations show that the tendency for chain formation is strongest for Au and Pt. Density functional theory calculations indicate...... that the metals which form chains exhibit pronounced many-atom interactions with strong bonding in low coordinated systems....

  17. Supply chain collaboration under uncertainty

    OpenAIRE

    Hasan, Saad; Eckert, Claudia; Earl, Chris

    2012-01-01

    In fluctuating economic conditions such as global recession, supply chains operate under changing conditions of uncertainty. The impact of this uncertainty and associated risk might be mitigated by collaboration. This paper proposes a model of supply chain collaboration based on information exchange and decision coordination at both the strategic and tactical levels. However, a collaborative supply chain can be exposed to associated risks such as the failure of individual actors. Governance r...

  18. Agent Simulation of Chain Bankruptcy

    OpenAIRE

    Yuichi Ikeda; Yoshi Fujiwara; Wataru Souma; Hideaki Aoyama; Hiroshi Iyetomi

    2007-01-01

    We have conducted an agent-based simulation of chain bankruptcy. The propagation of credit risk on a network, i.e., chain bankruptcy, is the key to nderstanding largesized bankruptcies. In our model, decrease of revenue by the loss of accounts payable is modeled by an interaction term, and bankruptcy is defined as a capital deficit. Model parameters were estimated using financial data for 1,077 listed Japanese firms. Simulations of chain bankruptcy on the real transaction network consisting o...

  19. Sampling Development

    OpenAIRE

    Adolph, Karen E.; Robinson, Scott R.

    2011-01-01

    Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of the enterprise. This article discusses how to sample development in order to accurately discern the shape of developmental change. The ideal solutio...

  20. The Service-Profit Chain

    DEFF Research Database (Denmark)

    Grønholdt, Lars; Martensen, Anne

    This paper examines the links between employee attitudes, customer loyalty and company profitability. From a conceptual point of view, this employee-customer-profit chain, also known as the service-profit chain, is well founded and generally accepted. But for many companies, it seems difficult to...... evidence of the employee-customer-profit chain. As it is possible to estimate the links, we have demonstrated their effect on company profitability. The research findings provide a better understanding of the service-profit chain and may help practitioners in improving company financial performance....

  1. Risikobasiertes Supply-Chain-Management

    DEFF Research Database (Denmark)

    Wieland, Andreas; Schinz, Philipp

    2015-01-01

    Das Management erlebt seit einigen Jahren dahingehend einen Paradigmenwechsel, dass nicht mehr Unternehmen als einzelne autonome Einheiten im Wettbewerb zueinander stehen, sondern die Supply Chains, in denen diese Unternehmen eingebunden sind. Ursachen hierfür sind beispielsweise die Auslagerung...... von Nicht-Kernprozessen auf vorgelagerte Stufen der Supply Chain oder auf Supply-Chain-Dienstleister sowie die Internationalisierung der Beschaffung. Dieser Paradigmenwechsel hat traditionelles Denken in den Schranken des Systems „Unternehmen“ abgelöst und zum Supply- Chain-Denken geführt, das vor......- und nachgelagerte Stufen des Systems „End-to-End-Supply-Chain“ einbezieht, etwa auch die Lieferanten von Lieferanten....

  2. Social Media and Supply Chain

    OpenAIRE

    Sonja Markova; Tatjana Petkovska-Mirčevska

    2013-01-01

    Web 2.0, also referred to as social media, is the use of the World Wide Web to increase creativity, information sharing, and collaboration among users. Social media is driving the rethinking of many of the principles of economics. The use of social media within supply chains is lagging behind their usage for other operational functions, however supply chain management is evolving into supply chain management 2.0.The purpose of this article is to provide researches of the supply chain manageme...

  3. Social Media and Supply Chain

    Directory of Open Access Journals (Sweden)

    Sonja Markova

    2013-02-01

    Full Text Available Web 2.0, also referred to as social media, is the use of the World Wide Web to increase creativity, information sharing, and collaboration among users. Social media is driving the rethinking of many of the principles of economics. The use of social media within supply chains is lagging behind their usage for other operational functions, however supply chain management is evolving into supply chain management 2.0.The purpose of this article is to provide researches of the supply chain management a reference with the main concepts of social media: social profiles, social applications, brand outposts and communities, and the social ecosystem.

  4. Supply Chain Coordination in Hospitals

    Science.gov (United States)

    Rego, Nazaré; de Sousa, Jorge Pinho

    This paper presents an innovative approach to support the definition of strategies for the design of alternative configurations of hospital supply chains. This approach was developed around a hybrid Tabu Search / Variable Neighbourhood Search metaheuristic, that uses several neighbourhood structures. The flexibility of the procedure allows its application to supply chains with different topologies and atypical cost characteristics. A preliminary computational experience shows the approach potential in solving large scale supply chain configuration problems. The future incorporation of this approach in a broader Decision Support System (DSS) will provide a tool that can significantly contribute to an increase of healthcare supply chains efficiency and encourage the establishment of collaborative partnerships between their members.

  5. Target Density Normalization for Markov Chain Monte Carlo Algorithms

    CERN Document Server

    Caldwell, Allen

    2014-01-01

    Techniques for evaluating the normalization integral of the target density for Markov Chain Monte Carlo algorithms are described and tested numerically. It is assumed that the Markov Chain algorithm has converged to the target distribution and produced a set of samples from the density. These are used to evaluate sample mean, harmonic mean and Laplace algorithms for the calculation of the integral of the target density. A clear preference for the sample mean algorithm applied to a reduced support region is found, and guidelines are given for implementation.

  6. Requirements of supply chain management in differentiating European pork chains

    NARCIS (Netherlands)

    Trienekens, J.H.; Wognum, P.M.

    2013-01-01

    This paper summarizes results obtained by research into pork chain management in the EU Integrated Project Q-Porkchains. Changing demands for intrinsic and extrinsic quality attributes of pork products impact the way supply chain management should be organized from the farmer down to the consumer. T

  7. Sampling Development

    Science.gov (United States)

    Adolph, Karen E.; Robinson, Scott R.

    2011-01-01

    Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of…

  8. Language sampling

    DEFF Research Database (Denmark)

    Rijkhoff, Jan; Bakker, Dik

    1998-01-01

    This article has two aims: [1] to present a revised version of the sampling method that was originally proposed in 1993 by Rijkhoff, Bakker, Hengeveld and Kahrel, and [2] to discuss a number of other approaches to language sampling in the light of our own method. We will also demonstrate how our...

  9. Environmental sampling

    International Nuclear Information System (INIS)

    Environmental Sampling (ES) is a technology option that can have application in transparency in nuclear nonproliferation. The basic process is to take a sample from the environment, e.g., soil, water, vegetation, or dust and debris from a surface, and through very careful sample preparation and analysis, determine the types, elemental concentration, and isotopic composition of actinides in the sample. The sample is prepared and the analysis performed in a clean chemistry laboratory (CCL). This ES capability is part of the IAEA Strengthened Safeguards System. Such a Laboratory is planned to be built by JAERI at Tokai and will give Japan an intrinsic ES capability. This paper presents options for the use of ES as a transparency measure for nuclear nonproliferation

  10. Sustainable Supply Chain Engagement in a Retail Environment

    Directory of Open Access Journals (Sweden)

    Anika Berning

    2015-05-01

    Full Text Available Sustainability is a key requirement for business success and is often regarded a competitive advantage if strategically managed. Sustainability-mature organisations look to their value chains where the retailer-supplier collaboration becomes critical in embedding sustainability. With this in mind, it is important to monitor retailer-supplier collaboration to determine whether it is effective. To facilitate this monitoring, the UN Global Compact Supply Chain Sustainability: A Guide for Continuous Improvement was consulted. The research question aimed to determine the progress of a prominent South African retailer regarding their sustainable supply chain management (SSCM and collaboration with suppliers. Therefore, this study attempts to apply the Supplier Engagement Continuum, extracted from the UN Global Compact Supply Chain Sustainability: A Guide for Continuous Improvement, in order to determine how the retailer is progressing in sustainable supply chain management. The qualitative and exploratory nature of the study necessitated a case study research design, while the technique of purposive sampling was used to select the sample of three suppliers. Data was collected by means of semi-structured interviews facilitated by an interview guide, and data analysis was conducted with Atlas.ti software. It was found that the retailer’s sustainable supply chain management can only be located on level one of the continuum. Supply chain sustainability in organisations lack the theoretical foundation of what sustainability really is. Therefore, the model was amended and an additional level was added to incorporate the education of sustainability.

  11. Detection of Francisella tularensis in blood by polymerase chain reaction.

    OpenAIRE

    Long, G W; Oprandy, J J; Narayanan, R. B.; Fortier, A H; Porter, K R; Nacy, C.A.

    1993-01-01

    We developed a polymerase chain reaction-based assay for Francisella tularensis which we evaluated by using spiked blood samples and experimentally infected mice. The assay detected both type A and type B F. tularensis at levels equivalent to one CFU/microliter of spiked blood. Results from polymerase chain reaction-based assay of limiting dilutions of blood from mice infected with the live vaccine strain agreed closely with results from blood culture.

  12. Performance Metrics in Supply Chain Management. Evidence from Romanian Economy

    OpenAIRE

    Alexandru Constăngioară

    2013-01-01

    The proposed empirical research uses a national sample of 19 Romanian companies from various industries to estimate de utilities for financial and non-financial performance measures used in Romanian supply chains. Empirical findings show that national supply chain measurement systems are balanced, using both financial and non-financial performance measures. The high estimated utility corresponding to indicators measuring logistic costs provides evidence that inter-functional and inter-organiz...

  13. INTERNATIONALIZATION OF BRAZILIAN FRANCHISE CHAINS: A COMPARATIVE STUDY

    OpenAIRE

    Pedro Lucas de Resende Melo; Felipe Mendes Borini; Moacir de Miranda Oliveira Junior; Ronaldo Couto Parente

    2015-01-01

    The primary goal of this paper is to comprehend the fundamental organizational differences between Brazilian franchise chains that only operate in the home market and Brazilian franchise chains that operate internationally. The sample chosen for this study comprehends 96 Brazilian franchises operating in the home market and 67 franchises with international operations; logistic regression was used to analyze data obtained from these sources. Our findings suggest that the development of a brand...

  14. Orbiting chains and rings

    Science.gov (United States)

    Breakwell, J. V.

    1983-01-01

    Two very different, highly flexible, space structures proposed during the last decade which involve analytical solution of certain partial differential equations are discussed. The first structure is an array, or hanging chain of aluminum beads which would serve as a convenient communicator if, under the influence of the Earth's gravity gradient, it assumes a local vertical orientation as it circles the Earth. Two passive schemes have been proposed for damping the rigid modes: twist the wire at the ends to provide non-zero moment of inertia about the vertical, thereby inducing relative motion of the two tips during rigid pitch or roll, and thus exercising a damper; and introduce weak lossy springs between the end sections and the main section; thereby providing linear coupling between the springs and all the in-plane (pitch) modes. The second structure is a complete ring of satellites cabled together at synchronous altitude. By a slight increase in altitude, the cable is in tension. This configuration is, however, unstable, and an active feedback control scheme is required to stabilize it. A possible scheme involves local cable length adjustment based on measurement of local altitude and shape variations and their rates.

  15. The Fast Simulation Chain for ATLAS

    CERN Document Server

    Basalaev, Artem; The ATLAS collaboration

    2016-01-01

    In order to generate the huge number of Monte Carlo events that will be required by the ATLAS experiment over the next several runs, a very fast simulation is critical. Fast detector simulation alone, however, is insufficient: with very high numbers of simultaneous proton-proton collisions expected in Run 3 and beyond, the digitization (detector response emulation) and event reconstruction time quickly become comparable to the time required for detector simulation. The ATLAS Fast Chain simulation has been developed to solve this problem. Modules are implemented for fast simulation, fast digitization, and fast track reconstruction. The application is sufficiently fast -- several orders of magnitude faster than the standard simulation -- that the simultaneous proton-proton collisions can be generated during the simulation job, so Pythia8 also runs concurrently with the rest of the algorithms. The Fast Chain has been built to be extremely modular and flexible, so that each sample can be custom-tailored to match ...

  16. Analysing the differences between theoretical and implemented supply chain strategies in selected organisations

    Directory of Open Access Journals (Sweden)

    Danie J. Nel

    2011-11-01

    Full Text Available Organisations can use supply chain strategies to gain a competitive advantage for the supply chain. A competitive advantage can be achieved by means of low cost or by means of differentiation. However, organisations have to implement the correct supply chain strategy. Returns on investment can be compromised if organisations implement an incorrect supply chain strategy. The objective of the article is to analyse the differences between theoretically implied and implemented supply chain strategies within selected organisations. The differences between supply chain strategies implied by literature and those implemented by selected organisations are analysed by determining how the organisations are managing their supply chain drivers. Organisations with lean supply chains should manage their supply chain drivers to achieve efficiency, while organisations with agile supply chains should manage their supply chain drivers with responsiveness towards customers' needs in mind. Non-probability sampling was used to include 13 organisations in the research. Six organisations are implementing different supply chain strategies to what literature principles are suggesting to them based on specific supply chain characteristics. An analysis is done on how these six organisations are managing their supply chain drivers.

  17. Negotiations in Supply Chain Management

    DEFF Research Database (Denmark)

    Zachariassen, Frederik

    2008-01-01

    negotiation literature. Subsequently, an empirical case study is presented, which explicitly aims at exploring the role of negotiations between members of a supply chain. Based on the findings, the paper concludes on specific, normative guidelines for negotiations for improved supply chain competitiveness...

  18. Environmental Management in Product Chains

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Forman, Marianne

    2009-01-01

    The chapter aims at giving background to companies, consultants, governmental regulators, NGOs etc. for the analysis and planning of environmental management in specific product chains through: A framework for understanding environmental management in product chains as shaped by the interaction...... between existing resources, norms and values and external pressures for environmental management (second section). A model for the types of corporate network relations that need to be mapped and understood in order to analyze and/or develop environmental management in a product chain (third section). An...... developed or needed to be developed as part of environmental management in a product chain (fifth and sixth sections). A framework for understanding, in particular, environmental management in product chains involving companies from different countries with different regulatory frameworks and some...

  19. Managing the Global Supply Chain

    DEFF Research Database (Denmark)

    Hsuan, Juliana; Skjøtt-Larsen, Tage; Kinra, Aseem;

    The world today faces global competition. The supply chain is vital part of the globalization process. Presenting a global view of the scope and complexity of supply chain management, this book reflects the rapid change that has taken place within the supply chain and its environment. This new...... well as current examples of best practice of managing supply chains in a global context....... edition has been fully updated with recent changes in concepts, technology and practice. Integration and collaboration are keywords in future competition. Firms must be agile and lean at the same time. The book gives an insightful overview of the conceptual foundations of the global supply chain, as...

  20. Environmental Management in Product Chains

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Forman, Marianne

    2009-01-01

    The chapter aims at giving background to companies, consultants, governmental regulators, NGOs etc. for the analysis and planning of environmental management in specific product chains through: A framework for understanding environmental management in product chains as shaped by the interaction...... between existing resources, norms and values and external pressures for environmental management (second section). A model for the types of corporate network relations that need to be mapped and understood in order to analyze and/or develop environmental management in a product chain (third section......). An overview of examples from our own research and from literature of the type and the role of environmental issues and initiatives in product chains (fourth section). A typology for characterizing corporate strategies as part of environmental management in product chains and characterizing those competencies...

  1. Managing the Global Supply Chain

    DEFF Research Database (Denmark)

    Skjøtt-Larsen, Tage; Schary, Philip B.; Mikkola, Juliana Hsuan;

    The world today faces global competition. The supply chain is vital part of the globalization process. Presenting a global view of the scope and complexity of supply chain management, this book reflects the rapid change that has taken place within the supply chain and its environment. This new...... edition has been fully updated with recent changes in concepts, technology and practice. Integration and collaboration are keywords in future competition. Firms must be agile and lean at the same time. The book gives an insightful overview of the conceptual foundations of the global supply chain, as...... well as current examples of best practice of managing supply chains in a global context....

  2. Association Between Supply Chain Glitches and Operating Performance

    OpenAIRE

    Kevin B. Hendricks; Vinod R. Singhal

    2005-01-01

    This paper empirically documents the association between supply chain glitches and operating performance. The results are based on a sample of 885 glitches announced by publicly traded firms. Changes in various operating performance metrics for the sample firms are compared against a sample of control firms of similar size and from similar industries. In the year leading up to the announcement, the control-adjusted mean percent changes in operating income, return on sales, and return on asset...

  3. Chains-into-Bins Processes

    CERN Document Server

    Batu, Tugkan; Cooper, Colin

    2010-01-01

    The study of {\\em balls-into-bins processes} or {\\em occupancy problems} has a long history. These processes can be used to translate realistic problems into mathematical ones in a natural way. In general, the goal of a balls-into-bins process is to allocate a set of independent objects (tasks, jobs, balls) to a set of resources (servers, bins, urns) and, thereby, to minimize the maximum load. In this paper, we analyze the maximum load for the {\\em chains-into-bins} problem, which is defined as follows. There are $n$ bins, and $m$ objects to be allocated. Each object consists of balls connected into a chain of length $\\ell$, so that there are $m \\ell$ balls in total. We assume the chains cannot be broken, and that the balls in one chain have to be allocated to $\\ell$ consecutive bins. We allow each chain $d$ independent and uniformly random bin choices for its starting position. The chain is allocated using the rule that the maximum load of any bin receiving a ball of that chain is minimized. We show that, fo...

  4. Optical regulation of cell chain

    Science.gov (United States)

    Liu, Xiaoshuai; Huang, Jianbin; Zhang, Yao; Li, Baojun

    2015-06-01

    Formation of cell chains is a straightforward and efficient method to study the cell interaction. By regulating the contact sequence and interaction distance, the influence of different extracellular cues on the cell interaction can be investigated. However, it faces great challenges in stable retaining and precise regulation of cell chain, especially in cell culture with relatively low cell concentration. Here we demonstrated an optical method to realize the precise regulation of cell chain, including removing or adding a single cell, adjusting interaction distance, and changing cell contact sequence. After injecting a 980-nm wavelength laser beam into a tapered optical fiber probe (FP), a cell chain of Escherichia colis (E. colis) is formed under the optical gradient force. By manipulating another FP close to the cell chain, a targeted E. coli cell can be trapped by the FP and removed from the chain. Further, the targeted cell can be added back to the chain at different positions to change the cell contact sequence. The experiments were interpreted by numerical simulations and the impact of cell sizes and shapes on this method was analyzed.

  5. Improving supply chain collaborations and performance of inefficient supply chain

    Directory of Open Access Journals (Sweden)

    M. Sanei

    2010-03-01

    Full Text Available Modern manufacturing enterprises are required to collaborate by their business partners through their business process operations such as design, manufacture, distribution, and aftersales services. And furthermore performance evaluation is of great importance for effective supply chain man agement. Therefore, DEA can help companies to remove some of the in efficiencies in operational processes in order to become more effective. The current paper develops one approach for determining the DEA projections for inefficient supply chains. Meanwhile this approach aims at providing an easy, efficient and more practical approach based on the performance evaluation for the multi-member supply chain. And ultimately, this model is illustrated by an numerical example of Chinese commercial bank, and case study application to provide of machine-making supply chain.

  6. 5. Sampling

    International Nuclear Information System (INIS)

    The sampling is described for radionuclide X-ray fluorescence analysis. Aerosols are captured with various filter materials whose properties are summed up in the table. Fine dispersed solid and liquid particles and gaseous admixtures may be captured by bubbling air through a suitable absorption solution. The concentration of small amounts of impurities from large volumes of air is done by adsorbing impurities on surfactants, e.g., activated charcoal, silica gel, etc. Aerosols may be captured using an electrostatic precipitator and aerosol fractions may be separated with a cascade impactor. Water sampling differs by the water source, i.e., ground water, surface water, rain or waste water. Soil samples are taken by probes. (ES)

  7. Markov chains theory and applications

    CERN Document Server

    Sericola, Bruno

    2013-01-01

    Markov chains are a fundamental class of stochastic processes. They are widely used to solve problems in a large number of domains such as operational research, computer science, communication networks and manufacturing systems. The success of Markov chains is mainly due to their simplicity of use, the large number of available theoretical results and the quality of algorithms developed for the numerical evaluation of many metrics of interest.The author presents the theory of both discrete-time and continuous-time homogeneous Markov chains. He carefully examines the explosion phenomenon, the

  8. New sensors and processing chain

    CERN Document Server

    Yaakoubi, Nourdin

    2014-01-01

    A vital tool for researchers, engineers, and students, New Sensors and Processing Chain focuses on the processing chain to set up in order to extract relevant information on various systems. Highlighting the design of new microsensors and various applications, the authors present recent progress in instrumentation and microsystem design, providing insight to the modification of the sensor itself as well as its environment. Various applications illustrate the presentations, which show how a processing chain is organized from the data acquired by a specific sensor.

  9. Quadratic Variation by Markov Chains

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Horel, Guillaume

    We introduce a novel estimator of the quadratic variation that is based on the the- ory of Markov chains. The estimator is motivated by some general results concerning filtering contaminated semimartingales. Specifically, we show that filtering can in prin- ciple remove the effects of market...... microstructure noise in a general framework where little is assumed about the noise. For the practical implementation, we adopt the dis- crete Markov chain model that is well suited for the analysis of financial high-frequency prices. The Markov chain framework facilitates simple expressions and elegant analyti...

  10. Food Chain Security and Vulnerability

    Science.gov (United States)

    Brunet, Sébastien; Delvenne, Pierre; Claisse, Frédéric

    In our contemporary societies, the food chain could be defined as a macro-technical system, which depends on a wide variety of actors and risks analysis methods. In this contribution, risks related to the food chain are defined in terms of "modern risks" (Beck 1992). The whole national economic sector of food production/distribution is vulnerable to a local accident, which can affect the functioning of food chain, the export programs and even the political system. Such a complex socio-technical environment is undoubtedly vulnerable to intentional act such as terrorism.

  11. Chains of Mean Field Models

    OpenAIRE

    Hassani, S. Hamed; Macris, Nicolas; Urbanke, Ruediger

    2011-01-01

    We consider a collection of Curie-Weiss (CW) spin systems, possibly with a random field, each of which is placed along the positions of a one-dimensional chain. The CW systems are coupled together by a Kac-type interaction in the longitudinal direction of the chain and by an infinite range interaction in the direction transverse to the chain. Our motivations for studying this model come from recent findings in the theory of error correcting codes based on spatially coupled graphs. We find tha...

  12. Good Criteria for Supply Chain Performance Measurement

    Directory of Open Access Journals (Sweden)

    Elisa Kusrini

    2014-03-01

    conducted by distributing questionnaires to supply chain actors from different industry fields (both manufacturing and services in Indonesia using random sampling techniques. Data analysis using pairwise comparisons with an analytical Hierarchy Process model showed that efficient criteria were more important than effective criteria. Efficient criteria consisted of three sub-criteria: the amount of data is not too much and low cost and output is presented in a simple form. Effective criteria consisted of the criteria in the order of importance as follows: clarity, validity, comprehensiveness, responsiveness and dynamics. Further research is needed for developing a model that meets these criteria

  13. Importance Sampling for the Infinite Sites Model*

    OpenAIRE

    Hobolth, Asger; Uyenoyama, Marcy K.; Wiuf, Carsten

    2008-01-01

    Importance sampling or Markov Chain Monte Carlo sampling is required for state-of-the-art statistical analysis of population genetics data. The applicability of these sampling-based inference techniques depends crucially on the proposal distribution. In this paper, we discuss importance sampling for the infinite sites model. The infinite sites assumption is attractive because it constraints the number of possible genealogies, thereby allowing for the analysis of larger data sets. We recall th...

  14. Carbon linear chains inside multiwalled nanotubes

    Science.gov (United States)

    Cazzanelli, E.; Caputi, L.; Castriota, M.; Cupolillo, A.; Giallombardo, C.; Papagno, L.

    2007-09-01

    Multiwalled carbon nanotubes have been deposited on graphite cathodes by using an arc discharge technique in He atmosphere, with the insertion of a catalytic Ni-Cr mixture as well as without catalysers. The topography of such deposition has been investigated by SEM, while a parallel micro-Raman study has revealed, in particular regions of the deposited cathodes, strong bands in the range 1780-1860 cm -1, assignable to linear carbon chains inside the nanotubes. The variation of intensity, frequency and bandwidth of such bands has been investigated, in relation with the spectral characters of the host multiwalled carbon nanotube. In the cathode deposited without catalyst a quite ordered configuration of multiwalled carbon nanotubes is obtained in the central zone, while the maximum concentration of linear carbon chains is found in a ring shaped zone just inside the border. In sample obtained with catalyst the deposited multiwalled carbon nanotubes appear always more disordered, and a remarkable concentration of carbon chains appears in some zones, with a more casual distribution.

  15. Influence of chain topology and bond potential on the glass transition of polymer chains simulated with the bond fluctuation model

    Energy Technology Data Exchange (ETDEWEB)

    Freire, J J [Departamento de Ciencias y Tecnicas FisicoquImicas, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), Senda del Rey 9, 28040 Madrid (Spain)], E-mail: jfreire@invi.uned.es

    2008-07-16

    The bond fluctuation model with a bond potential has been applied to investigation of the glass transition of linear chains and chains with a regular disposition of small branches. Cooling and subsequent heating curves are obtained for the chain energies and also for the mean acceptance probability of a bead jump. In order to mimic different trends to vitrification, a factor B gauging the strength of the bond potential with respect to the long-range potential (i.e. the intramolecular or intermolecular potential between indirectly bonded beads) has been introduced. (A higher value of B leads to a preference for the highest bond lengths and a higher total energy, implying a greater tendency to vitrify.) Different cases have been considered for linear chains: no long-range potential, no bond potential and several choices for B. Furthermore, two distinct values of B have been considered for alternate bonds in linear chains. In the case of the branched chains, mixed models with different values of B for bonds in the main chain and in the branches have also been investigated. The possible presence of ordering or crystallization has been characterized by calculating the collective light scattering function of the different samples after annealing at a convenient temperature below the onset of the abrupt change in the curves associated with a thermodynamic transition. It is concluded that ordering is inherited more efficiently in the systems with branched chains and also for higher values of B. The branched molecules with the highest B values in the main chain bonds exhibit two distinct transitions in the heating curves, which may be associated with two glass transitions. This behavior has been detected experimentally for chains with relatively long flexible branches.

  16. Bibliometric Application of Markov Chains.

    Science.gov (United States)

    Pao, Miranda Lee; McCreery, Laurie

    1986-01-01

    A rudimentary description of Markov Chains is presented in order to introduce its use to describe and to predict authors' movements among subareas of the discipline of ethnomusicology. Other possible applications are suggested. (Author)

  17. Designing the Reverse Supply Chain

    DEFF Research Database (Denmark)

    Gobbi, Chiara

    2011-01-01

    supply chain. Research limitations/implications – The focus is restricted to the industry of electrical and electronic products. Practical implications – Based on the outcome of the study, managers are able to determine the basic prerequisites for the design of their reverse supply chains. Originality......Purpose – The purpose of this paper is to explore the impact of the product residual value (PRV) and the loss of value over time of returned products in the reverse supply chain configuration. It also examines whether or not the distinction of Fisher's functional and innovative products holds for...... the reverse supply chain. Design/methodology/approach – In order to identify the relevance of the Fisher model, the model needs to be recast in terms of PRV, which, in this context, is considered the independent variable in the reverse logistics arena. Products defined as innovative in Fisher...

  18. Supply Chain Shipment Pricing Data

    Data.gov (United States)

    US Agency for International Development — This data set provides supply chain health commodity shipment and pricing data. Specifically, the data set identifies Antiretroviral (ARV) and HIV lab shipments to...

  19. Supply Chain Management and Hypercompetition

    OpenAIRE

    Kotzab, H,; Grant, DB; Teller, C.; Halldorsson, A

    2008-01-01

    Firms nowadays face significant challenges in their operating environments, which have been characterised in two different ways. From a strategic management perspective these environments are in a state of hypercompetition while from a logistics or supply chain perspective these environments require market responsiveness predicated upon agile supply chains. However, firms must also rely on many interorganizational relationships to ensure efficient and effective movements within their supply c...

  20. Risk Management in Supply Chains

    OpenAIRE

    Sharma Satyendra Kumar

    2009-01-01

    With increasing competition and globalization, the importance of risk management is increasing in extended enterprises. There are evidences that companies who excel in managing risks outperform their rivals. The ability to be “adaptive” in Supply Chain Management (SCM) has been the subject of much discussion as a means to deal with the increasing level of uncertainty in global supply chains. Traditional approaches to SCM focused on the “goodness” of a plan and sought to eliminate variability....

  1. Product Classification in Supply Chain

    OpenAIRE

    Xing, Lihong; Xu, Yaoxuan

    2010-01-01

    Oriflame is a famous international direct sale cosmetics company with complicated supply chain operation but it lacks of a product classification system. It is vital to design a product classification method in order to support Oriflame global supply planning and improve the supply chain performance. This article is aim to investigate and design the multi-criteria of product classification, propose the classification model, suggest application areas of product classification results and intro...

  2. Demand chain management - The evolution

    OpenAIRE

    D Ericsson

    2011-01-01

    The concepts of Supply Chain Management (SCM) and Demand Chain Management (DCM) are among the new and debated topics concerning logistics in the literature. The question considered in this paper is: “Are these concepts needed or will they just add to the confusion?” Lasting business concepts have always evolved in close interaction between business and academia. Different approaches start out in business and they are then, more or less si- multaneously, aligned, integrated, systemised and str...

  3. The chain re-action

    CERN Multimedia

    2009-01-01

    On 18 March, beam commissioning started in the first ‘link’ of the accelerator chain – LINAC 2. This marks the start of what will be the longest period of beam operations in CERN’s history, with the accelerator complex remaining operational throughout the winter to supply the LHC. The Bulletin finds out what is being done to make sure the whole chain is ready for this historic run.

  4. A Qualitative Approach for Assessing Resiliency in Supply Chains

    Directory of Open Access Journals (Sweden)

    Nikookar Hassan

    2014-12-01

    Full Text Available The ultimate goal of this study is to develop a comprehensive and competitive management system to enhance resilience capability of supply chains. In addition, the study aims to identify and eliminate barriers affecting resilience by identifying the factors may cause trouble in the near future. The theoretical framework was established to summarize the significant finding in the area of resilient supply chain and as a guideline for the empirical part. A qualitative approach based on multi criteria decision making process has been adopted in order to gather data through in-depth interviews. The developed method to evaluate resilience capability through supply chains piloted in a sample of five companies involved in an automotive supply chain.

  5. A Note on Perfect Slice Sampling

    OpenAIRE

    Hörmann, Wolfgang; Leydold, Josef

    2006-01-01

    Perfect slice sampling is a method to turn Markov Chain Monte Carlo (MCMC) samplers into exact generators for independent random variates. We show that the simplest version of the perfect slice sampler suggested in the literature does not always sample from the target distribution. (author's abstract)

  6. Sports Nutrition Food Industry Chain Development Research

    OpenAIRE

    Jie Yin

    2015-01-01

    Through the study of Henan sports nutrition food industry chain optimization, the study analyses development advantage and competitive advantage of Henan in sports nutrition food industry chain and existing problems and challenges in Henan sports nutrition food industry chain and at the same time introduces the theory of supply chain management to the development of sports nutrition food industry chain, clearly optimizes countermeasures of sports nutrition food industry chain. Pointing out sp...

  7. Risk Management in Biopharmaceutical Supply Chains

    OpenAIRE

    Ma, Yao

    2011-01-01

    Biopharmaceutical supply chains present considerable complexity issue for the formulation of optimal plans due to significant uncertainty in the supply chain. The primary goal of biopharmaceutical supply chain planning is to provide reliable supply to patients while coping with various supply chain risks. In chapter 1 first I discuss the key elements and basic characteristics of the biopharmaceutical supply chain . Then I present the major challenges in biopharmaceutical supply chain planning...

  8. Finance Management Based on Value Chain Management

    OpenAIRE

    Wenjing Shang; Jianping Yang

    2009-01-01

    The theory of value chain has brought about a new idea for enterprise management. In recent years, scholars inside and outside have kept on researching how to meet the needs for management by means of studying the value chain of enterprises. In a sense, the value chain management has penetrated into human mind, concerning with every aspect of enterprise management, such as accounting of value chain, human resource management of value chain, and cost management of value chain. Based on an anal...

  9. What is a Responsible Supply Chain?

    OpenAIRE

    Terje Ingebrigt Vaaland; Owusu, Richard A.

    2012-01-01

    The paper introduces the concept of responsible supply chain based on two dimensions, the core processes of a supply chain and the concept of corporate social responsibility (CSR). It is suggested that a responsible supply chain is achieved through manifested core values of the supply chain actors, strategies, and tactics. The paper further discusses the individual supply chain actors’ responsibility in securing a responsible supply chain beyond the actors’ direct control. A conceptual model ...

  10. Returning Samples from Enceladus

    Science.gov (United States)

    Tsou, P.; Kanik, I.; Brownlee, D.; McKay, C.; Anbar, A.; Glavin, D.; Yano, H.

    2012-12-01

    search for chemical biosignatures to understand the habitability potential of the subsurface ocean of Enceladus [Glavin et al. 2011]. By assessing the chiral excess among different amino acids, identifying chains of amino acids, isolate distinct sequences of these chains and the same for nucleic acids, we can formulate a new set of hypotheses to address some of the key science questions required for investigating the stage of extraterrestrial life at Enceladus beyond the four factors of habitability. Criticality of Analyses - For extraterrestrial organic matter analyses such as chirality and compound-specific isotopes, the repeatable robustness of laboratory measurements is a necessity. These analyses require a series of chemical extraction and derivatization steps prior to analysis that is adapted to the sample and procedures results-driven. The Stardust mission is an excellent example of the challenges in the analysis of organics. Confirmation of the cometary origin of the amino acid glycine from comet Wild 2 was obtained 3 years after the samples were returned to Earth. This long period of laboratory development allowed several modifications to the extraction protocol, multiple analytical techniques and instrumentations. Reference: Tsou et al., Astrobiology, in press 2012. McKay et al. Astrobiology 2008. Waite et al. Nature V 460 I 7254, 2009. Postberg et al. EPSC 642P 2011. Glavin et al., LPSC, #5002, 2011.

  11. Demand chain management - The evolution

    Directory of Open Access Journals (Sweden)

    D Ericsson

    2011-06-01

    Full Text Available The concepts of Supply Chain Management (SCM and Demand Chain Management (DCM are among the new and debated topics concerning logistics in the literature. The question considered in this paper is: “Are these concepts needed or will they just add to the confusion?” Lasting business concepts have always evolved in close interaction between business and academia. Different approaches start out in business and they are then, more or less si- multaneously, aligned, integrated, systemised and structured in academia. In this way a terminology (or language is provided that helps in further diffusion of the concepts. There is a lack of consensus on the definition of the concept of SCM. This may be one of the major reasons for the difficulty in advancing the science and measuring the results of implementation in business. Relationships in SCM span from rather loose coalitions to highly structured virtual network integrations. DCM is a highly organised chain in which the key is mutual interdependence and partnership. The purpose is to create a distinctive competence for the chain as a whole that helps to identify and satisfy customer needs and wishes. The classical research concerning vertical marketing systems is very helpful in systemising the rather unstructured discussions in current SCM research. The trend lies in increasing competition between channels rather than between companies, which in turn leads to the creation of channels with a high degree of partnership and mutual interdependence between members. These types of channels are known as organised vertical marketing systems in the classic marketing channel research. The behaviour in these types of channels, as well as the formal and informal structures, roles in the network, power and dependence relations, etc. are well covered topics in the literature. The concept of vertical marketing systems lies behind the definition of demand chains and demand chain management proposed in this paper. A

  12. Linear chains and chain-like fractals from electrostatic heteroaggregation.

    Science.gov (United States)

    Kim, Anthony Y; Hauch, Kip D; Berg, John C; Martin, James E; Anderson, Robert A

    2003-04-01

    The internal structure of materials prepared by aggregation of oppositely charged polystyrene spheres (electrostatic heteroaggregation) is investigated by static light scattering, optical microscopy, and Brownian dynamics simulation. Light scattering indicates ultralow mass fractal dimensions, as low as 1.2. Such low fractal dimensions, approaching the theoretical limit of a linear object, imply a chaining mechanism. Optical micrographs reveal linear chains with the particle charge alternating down the chains. Brownian dynamics simulation gives additional support for a chaining mechanism. For the polystyrene system (120-nm primary particle diameters), the fractal dimension is found to increase from 1.2 to 1.7 as the background electrolyte is increased. In terms of electrostatic screening, the results match those reported recently for larger polystyrene spheres. The low fractal dimensions appear to represent a crossover from linear chains to a structure of diffusion-limited aggregates; however, experiments under density-neutral conditions imply that sedimentation plays an important role in the formation of ultralow fractal dimensions. The practical implication is that microcomposites with a locally uniform distribution of starting materials and almost any degree of branching can be prepared from oppositely charged particles. PMID:12742045

  13. A demand chain design for Chinese oatmeal companies

    Directory of Open Access Journals (Sweden)

    Haitao Wen

    2015-04-01

    Full Text Available Purpose: The purpose of this paper is to provide a demand chain design framework for Chinese small and medium enterprises in the oatmeal industry, to help them blaze a new trail in China's oatmeal market. Design/methodology/approach: The approach using in the demand chain design is extended Quality Function Development (QFD, which provides a communication tool so that designers can find a way to integrate customers’ needs into design chain. Findings: This paper illustrates an investigation of oatmeal consumed in China, and the result shows 9 factors influencing consumer’s purchasing decisions mostly. Then use these factors to design the demand chain, and the most important processes and tasks for the enterprises are come out from the fist and the second House of Quality (HOQ, which are the main part of the design. Finally, a demand chain design is completed. Research limitations/implications: It is an application of a demand chain design framework in real Chinese oatmeal market, but the data sample is limited. Consumption surveys should have more data sources with more detailed consumer groups. And the design model needs more real-life examples to verify Practical implications: Since oatmeal products industry develops rapidly in China, oatmeal market is becoming a vast bright market. And due to the low customer satisfaction of Chinese oatmeal market, it is crucial that companies can find a way to design their demand chain, so they can completely meet the needs. Originality/value: A demand chain design framework is presented with being specific to Chinese oatmeal market. It shows a real-life example of demand chain design, and provides the domestic oatmeal companies with an approach to compete in the market.

  14. Supply Chain Management Practices in Toy Supply Chains

    DEFF Research Database (Denmark)

    Wong, Chee Yew; Arlbjørn, Jan Stentoft; Johansen, John

    2005-01-01

    Purpose - Innovative products usually experience highly unpredictable and variable demand. This is especially valid for the volatile and seasonal toy industry, which produces high obsolete inventory, lost sales and markdown. In such a volatile industry, what supply chain management (SCM) practices...... manufacturers (traditional mass-production or push-models). These low-responsive practices in the toy supply chain are not caused only by slow knowledge diffusion. SCM know-how is not yet capable of managing such levels of volatility and seasonality. Therefore, explanations of these theoretical gaps and what...... are applicable and effective? This study seeks to explore SCM practices, and identify practical and theoretical gaps in toy supply chains. Design/methodology/approach - This article includes a longitudinal and in-depth case study during the past year in an international toy manufacturer, which...

  15. Dynamic temperature selection for parallel-tempering in Markov chain Monte Carlo simulations

    OpenAIRE

    Vousden, Will; Farr, Will M.; Mandel, Ilya

    2015-01-01

    Modern problems in astronomical Bayesian inference require efficient methods for sampling from complex, high-dimensional, often multi-modal probability distributions. Most popular methods, such as Markov chain Monte Carlo sampling, perform poorly on strongly multi-modal probability distributions, rarely jumping between modes or settling on just one mode without finding others. Parallel tempering addresses this problem by sampling simultaneously with separate Markov chains from tempered versio...

  16. Competitive behaviour in supply chains

    Directory of Open Access Journals (Sweden)

    Sylwia Konecka

    2014-06-01

    Full Text Available Background: The article deals with the results of literature and empirical research into competitiveness and behaviour of entities in supply chains. Methods: A research hypothesis has been formulated that both partnership as well as dominance relations occur between enterprises functioning as suppliers-consignees. In order to verify the hypothesis a survey was completed in 2012. It encompassed 116 enterprises (manufacturers - 33, service providers - 32 and sellers - 24 as well as enterprises selling goods and providing services - 27 of which 54 were large, 26 medium and 36 were small enterprises. Competitive behaviour in supply chains has been identified and analysed. Furthermore, the authors intended to identify, reveal and examine possible interdependences between competitive behaviour and behaviour typical of supply chain strategies. Results and conclusions: The analysis of survey results revealed a tendency to preserve equilibrium between a chain leader and dependent enterprises. It may be easily justified in practice as on the one hand there is a need to keep the supply chain competitive and on the other hand to avoid the interruptions, which could occur as a result of elimination of dependent enterprises.

  17. Chains of Mean Field Models

    CERN Document Server

    Hassani, S Hamed; Urbanke, Ruediger

    2011-01-01

    We consider a collection of mean field spin systems, each of which is placed on the positions of a one-dimensional chain, coupled together by a Kac-type interaction along the chain. We analyze the simplest possible cases where the individual system is a Curie-Weiss model, possibly with a random field. We are interested in the regime where the size of each mean field model tends to infinity and, the length of the chain and range of the Kac interaction are large but finite. Below the critical temperature, there appears a series of equilibrium states representing kink-like interfaces between the two equilibrium states of the individual system. The van der Waals curve oscillates periodically around the Maxwell plateau. These oscillations have a period inversely proportional to the chain length and an amplitude exponentially small in the range of the interaction; in other words the spinodal points of the chain model lie exponentially close to the phase transition threshold. The amplitude of the oscillations is clo...

  18. Design and synthesis of side-chain conformationally restricted phenylalanines and their use for structure-activity studies on tachykinin NK-1 receptor.

    Science.gov (United States)

    Josien, H; Lavielle, S; Brunissen, A; Saffroy, M; Torrens, Y; Beaujouan, J C; Glowinski, J; Chassaing, G

    1994-05-27

    Constrained analogues of phenylalanine have been conceptually designed for analyzing the binding pockets of Phe7 (S7) and Phe8 (S8), two aromatic residues important for the pharmacological properties of SP, i.e., L-tetrahydroisoquinoleic acid, L-diphenylalanine, L-9-fluorenylglycine (Flg), 2-indanylglycine, the diastereomers of L-1-indanylglycine (Ing) and L-1-benz[f]indanylglycine (Bfi), and the Z and E isomers of dehydrophenylalanine (delta ZPhe, delta EPhe). Binding studies were performed with appropriate ligands and tissue preparations allowing the discrimination of the three tachykinin binding sites, NK-1, NK-2, and NK-3. The potencies of these agonists were evaluated in the guinea pig ileum bioassay. According to the binding data, we can conclude that the S7 subsite is small, only the gauche (-) probe [(2S,3S)-Ing7]SP presents a high affinity for specific NK-1 binding sites. Surprisingly, the [delta EPhe7]SP analogue, which projects the aromatic ring toward the trans orientation, is over 40-fold more potent than the Z isomer, [delta ZPhe7]SP. A plausible explanation of these conflictual results is that either the binding protein quenches the minor trans rotamer of [(2S,3S)-Ing7]SP in solution or this constrained amino acid side chain rotates when inserted in the protein. In position 8, the high binding affinities of [Flg8]SP and [(2S,3S)-Bfi8]SP suggest that the S8 subsite is large enough to accept two aromatic rings in the gauche (-) and one aromatic ring in the trans direction. Peptides bearing two conformational probes in positions 7, 8, or 9 led to postulate that S7, S8, and S9 subsites are independent from each other. The volumes available for side chains 7 and 8 can be estimated to be close to 110 and 240 A3, respectively. The large volume of the S8 subsite raises question on the localization of the SP-binding site in the NK-1 receptor. If SP were to bind in the transmembrane domains, the cleft defined by the seven transmembrane segments must rearrange

  19. Exploring Mass Perception with Markov Chain Monte Carlo

    Science.gov (United States)

    Cohen, Andrew L.; Ross, Michael G.

    2009-01-01

    Several previous studies have examined the ability to judge the relative mass of objects in idealized collisions. With a newly developed technique of psychological Markov chain Monte Carlo sampling (A. N. Sanborn & T. L. Griffiths, 2008), this work explores participants; perceptions of different collision mass ratios. The results reveal…

  20. Intrathecal synthesis of free immunoglobulin light chains in multiple sclerosis

    DEFF Research Database (Denmark)

    Krakauer, M; Schaldemose Nielsen, H; Jensen, J; Sellebjerg, F

    1998-01-01

    OBJECTIVE: The detection of oligoclonal immunoglobulin free light chains (FLC) in the diagnosis of multiple sclerosis (MS) was compared to IgG isoelectric focusing. MATERIAL AND METHODS: Cerebrospinal fluid and serum samples from 69 patients with possible first attacks of MS, 50 patients with...

  1. Chain reconfiguration in active noise

    Science.gov (United States)

    Samanta, Nairhita; Chakrabarti, Rajarshi

    2016-05-01

    In a typical single molecule experiment, the dynamics of an unfolded protein is studied by determining the reconfiguration time using long-range Förster resonance energy transfer, where the reconfiguration time is the characteristic decay time of the position correlation between two residues of the protein. In this paper we theoretically calculate the reconfiguration time for a single flexible polymer in the presence of active noise. The study suggests that though the mean square displacement grows faster, the chain reconfiguration is always slower in the presence of long-lived active noise with exponential temporal correlation. Similar behavior is observed for a worm-like semi-flexible chain and a Zimm chain. However it is primarily the characteristic correlation time of the active noise and not the strength that controls the increase in the reconfiguration time. In brief, such active noise makes the polymer move faster but the correlation loss between the monomers becomes slow.

  2. Ligand chain length conveys thermochromism.

    Science.gov (United States)

    Ganguly, Mainak; Panigrahi, Sudipa; Chandrakumar, K R S; Sasmal, Anup Kumar; Pal, Anjali; Pal, Tarasankar

    2014-08-14

    Thermochromic properties of a series of non-ionic copper compounds have been reported. Herein, we demonstrate that Cu(II) ion with straight-chain primary amine (A) and alpha-linolenic (fatty acid, AL) co-jointly exhibit thermochromic properties. In the current case, we determined that thermochromism becomes ligand chain length-dependent and at least one of the ligands (A or AL) must be long chain. Thermochromism is attributed to a balanced competition between the fatty acids and amines for the copper(II) centre. The structure-property relationship of the non-ionic copper compounds Cu(AL)2(A)2 has been substantiated by various physical measurements along with detailed theoretical studies based on time-dependent density functional theory. It is presumed from our results that the compound would be a useful material for temperature-sensor applications. PMID:24943491

  3. Precise Nanoelectronics with Adatom Chains

    Science.gov (United States)

    Yamada, Toshishige

    1999-01-01

    Adatom chains on an atomically regulated substrate will be building components in future precise nanoelectronics. Adatoms need to be secured with chemical bonding, but then electronic isolation between the adatom and substrate systems is not guaranteed. A one-dimensional model shows that good isolation with existence of surface states is expected on an s-p crossing substrate such as Si, Ge, or GaAs, reflecting the bulk nature of the substrate. Isolation is better if adatoms are electronically similar to the substrate atoms, and can be manipulated by hydrogenation. Chain structures with group IV adatoms with two chemical bonds, or group III adatoms with one chemical bond, are semiconducting, reflecting the surface nature of the substrate. These structures are unintentionally doped due to the charge transfer across the chemical bonds. Physical properties of adatom chains have to be determined for the unified adatom-substrate system.

  4. Thermophoresis of linear polymer chains

    Science.gov (United States)

    Bringuier, Eric

    2011-05-01

    The thermophoresis of a linear polymer chain in a solvent is examined theoretically and is shown to be due to the action of two forces. The first one is Waldmann's thermophoretic force (stemming from the departure of the molecular-velocity distribution from Maxwell's equilibrium distribution), which here is extrapolated to a dense medium by using scaling considerations. The second force is due to the fact that the viscous friction varies with position owing to the temperature gradient, which brings a zeroth-order correction to the Stokes law of friction. The present scaling theory is compared with recent experiments and is found to account for: (i) the existence of both signs of the thermodiffusion coefficient; (ii) the absolute magnitude of the coefficient; (iii) the fact that it is independent of the chain length in the high-polymer limit; and (iv) the dependence on solvent viscosity. The variation of the coefficient for short chains is also examined.

  5. Environmental management in product chains

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Forman, Marianne; Hansen, Anne Grethe

    of environmental initiatives, a number of recommendations for governmental regulation, which can support the further diffusion of environmental management in product chains, are developed. Furthermore, the report describes a number of theoretical perspectives from sociology of technology, organisation theory......This report presents the analyses of the shaping, implementation and embedding of eight types of environmental initiatives in product chains. The analyses focus on • the role of the type of product and branch, of the size of the companies and of governmental regulation • the focus...... of the environmental concerns and the reductions in environmental impact • organisational changes which have been part of the embedding of the initiatives The analyses are based on 25 cases from national and international product chains involving one or more Danish companies. Based on the analyses of the eight types...

  6. Towards biotracing in food chains

    DEFF Research Database (Denmark)

    Hoorfar, Jeffrey; Wagner, Martin; Jordan, Kieran;

    2011-01-01

    integration of these disciplines will lead to better capability in full-chain tracing and tracking biological contaminations (biotracing). The advantages of improved biotraceability are faster intervention, limited recalls and more targeted remedial action. The project is not dealing with risk assessments but......Biotracing is tracing (backward)/tracking (forward) biological contamination in the food/feed chain. Advances in detection technologies, improvements in molecular marker identification, clearer understanding of pathogenicity markers, improved modelling methodologies and, more importantly, the......, and 21 cross-disciplinary work packages that cover tracing and tracking of contamination in feed, meat and dairy chains, in addition to accidental and deliberate contamination of bottled water. The BIOTRACER Consortium consists of 46 partners, including Europe's largest food/feed industries, several...

  7. Chain reconfiguration in active noise

    International Nuclear Information System (INIS)

    In a typical single molecule experiment, the dynamics of an unfolded protein is studied by determining the reconfiguration time using long-range Förster resonance energy transfer, where the reconfiguration time is the characteristic decay time of the position correlation between two residues of the protein. In this paper we theoretically calculate the reconfiguration time for a single flexible polymer in the presence of active noise. The study suggests that though the mean square displacement grows faster, the chain reconfiguration is always slower in the presence of long-lived active noise with exponential temporal correlation. Similar behavior is observed for a worm-like semi-flexible chain and a Zimm chain. However it is primarily the characteristic correlation time of the active noise and not the strength that controls the increase in the reconfiguration time. In brief, such active noise makes the polymer move faster but the correlation loss between the monomers becomes slow. (paper)

  8. Differential evolution Markov chain with snooker updater and fewer chains

    Energy Technology Data Exchange (ETDEWEB)

    Vrugt, Jasper A [Los Alamos National Laboratory; Ter Braak, Cajo J F [NON LANL

    2008-01-01

    Differential Evolution Markov Chain (DE-MC) is an adaptive MCMC algorithm, in which multiple chains are run in parallel. Standard DE-MC requires at least N=2d chains to be run in parallel, where d is the dimensionality of the posterior. This paper extends DE-MC with a snooker updater and shows by simulation and real examples that DE-MC can work for d up to 50--100 with fewer parallel chains (e.g. N=3) by exploiting information from their past by generating jumps from differences of pairs of past states. This approach extends the practical applicability of DE-MC and is shown to be about 5--26 times more efficient than the optimal Normal random walk Metropolis sampler for the 97.5% point of a variable from a 25--50 dimensional Student T{sub 3} distribution. In a nonlinear mixed effects model example the approach outperformed a block-updater geared to the specific features of the model.

  9. Quantum crystals and spin chains

    Energy Technology Data Exchange (ETDEWEB)

    Dijkgraaf, Robbert [KdV Institute for Mathematics, University of Amsterdam, Plantage Muidergracht 24, 1018 TV Amsterdam (Netherlands); Institute for Theoretical Physics, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands); Orlando, Domenico [Institut de Physique, Universite de Neuchatel, Rue Breguet 1, CH-2000 Neuchatel (Switzerland); Reffert, Susanne [Institute for Theoretical Physics, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands)], E-mail: sreffert@gmail.com

    2009-04-21

    In this article, we discuss the quantum version of the melting crystal corner in one, two, and three dimensions, generalizing the treatment for the quantum dimer model. Using a mapping to spin chains we find that the two-dimensional case (growth of random partitions) is integrable and leads directly to the Hamiltonian of the Heisenberg XXZ ferromagnet. The three-dimensional case of the melting crystal corner is described in terms of a system of coupled XXZ spin chains. We give a conjecture for its mass gap and analyze the system numerically.

  10. Health Care Provider Value Chain

    OpenAIRE

    Kawczynski, Lukasz; Taisch, Marco

    2010-01-01

    In every society there is a need for an efficient health care system. This paper aims to propose a value definition and a value chain model within the health care. In order to define value patients and experts were surveyed. The proposed definition offers a complex way of looking at the value within the health care sector. The proposal of the value chain model is anticipated with a value stream mapping activities and experts interviews. Proposed model offers consistent way of looking at the v...

  11. MANAGING RISK IN SUPPLY CHAIN

    OpenAIRE

    Karppinen, Sami

    2015-01-01

    In this master thesis the focus was to study risk management in supply chain management. During the work different types of risks were studied and how they affect purchasing in industry. The purpose of the work was also to enhance the writer’s ability to do his own daily work and to bring new views to his employer for managing a supply chain. In this work different techniques which have been introduced in the industry were reviewed. During the work, an interview survey was made among the ...

  12. Thermodynamics of Dipolar Chain Systems

    DEFF Research Database (Denmark)

    R. Armstrong, J.; Zinner, Nikolaj Thomas; V. Fedorov, D.;

    2012-01-01

    The thermodynamics of a quantum system of layers containing perpendicularly oriented dipolar molecules is studied within an oscillator approximation for both bosonic and fermionic species. The system is assumed to be built from chains with one molecule in each layer. We consider the effects of the...... numerically. Our findings indicate that thermodynamic observables, such as the heat capacity, can be used to probe the signatures of the intralayer interaction between chains. This should be relevant for near future experiments on polar molecules with strong dipole moments....

  13. Chemical potential and dimensions of chain molecules in athermal environments

    Science.gov (United States)

    Escobedo, Fernando A.

    A recently developed method for the simulation of chemical potentials of chain molecules (EVALENCH) is applied here to obtain the chemical potential, the mean square end-to-end distance (R2n) and the mean square radius of gyration (R2g) of dilute chains in different athermal media. The environments considered in this work are a frozen network structure, a deformable network matrix and a monomeric solvent at various densities. The properties of all chain lengths smaller than a preset maximum are calculated in a single simulation. A novel method is also presented for locating and computing the fraction of sampling space available to append one segment of an existing chain. This method enhances the range of densities where simulations of chemical potential are feasible. Simulated chemical potentials are compared with the predictions of two theories; good agreement is found in both cases. We find that R2n and R2g are reduced as the density of the medium is increased (network or solvent), while they are increased when the network is frozen and as the monomeric solvent size is made larger than that of the chain sites. At the conditions studied here, no direct evidence of chain collapse is observed.

  14. Reseach of Supply Chain Modeling Technology

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The supply chain modeling technology is research. Firstly, the concept of supply chain and supply chain management is introduced. Secondly, enterprise-modeling methods, such as CIM-OSA, GIM-GRAI, PERA and ARIS, are analyzed and compared. The supply chain modeling technology is studied. Then the ARIS-based supply chain modeling method is proposed and the supply chain operation reference model is set up. Finally, the applications of ARIS-based supply chain modeling method in Shanghai Turbine Generator Co. Ltd. (STGC) is described in detail.

  15. Evaluation of the Detection of Borrelia burgdorferi DNA in Urine Samples by Polymerase ChainReaction for Diagnosing Lyme Disease%聚合酶链法检测莱姆病患者尿液中伯氏疏螺旋体DNA(附17例报道)

    Institute of Scientific and Technical Information of China (English)

    谭毓绘; 朱沂; 刘勇; 孙荷; 龙江; 牛晓珊; 于鲁海; 莫合塔尔; 阿斯亚; 李红燕

    2012-01-01

    目的:评估聚合酶链反应(PCR)检测莱姆病患者尿液中伯氏疏螺旋体DNA的诊断价值.方法:2004至2006年来自新疆莱姆病自然疫源地临床疑似莱姆病患者17例(均有蜱暴露史和莱姆病临床证据者)和6例以前确诊并治疗后完全恢复的莱姆病患者,共23例为病例组;另选择25例非疑似莱姆病患者为对照组.应用PCR方法检测尿液中伯氏疏螺旋体DNA,采用间接免疫荧光(IFA)检测血清伯氏疏螺旋体抗体.结果:①17例莱姆病患者临床表现呈多系统损害.12/17例(70.59%)为神经型(周围神经病3例,其中1例合并下肢瘀积性皮炎;游走性红斑并发莱姆脑病2例;脑膜脑炎2例;脑炎2例;脑膜炎、脑干炎和脊髓炎各1例);流感样症状2例,其中伴皮疹1例;余心脏型、精神障碍和肝病型各1例.②PCR伯氏疏螺旋体DNA检测阳性17/17例(总阳性率100%).4例血清IFA试验伯氏疏螺旋体抗体阳性.以前确诊并治疗者6例及对照组25例尿PCR伯氏疏螺旋体DNA和血清IFA试验伯氏疏螺旋体抗体均阴性.③10例完成抗生素治疗后3个月复查,9例PCR伯氏疏螺旋体DNA检测阴性(包括3例晚期莱姆病患者),1例2年复查时仍阳性;4例血清伯氏疏螺旋体抗体阳性者复查均阴性.④早期莱姆病多采用几周的抗生素治疗方案.结论:PCR检测尿液中伯氏疏螺旋体DNA是莱姆病一个有价值的诊断工具.%Aim: To estimate the value of detecting Borrelia bugdorferi DNA in urine samples by polymerase chain reaction (PCR) for diagnosing Lyme disease. Methods: 17 patients suspected of Lyme disease come from nature foci and 25 cases with Non-Lyme disease evidence were enrolled from 2004 to 2006. Lyme serology was performed by IF A. Urine samples were examined by PCR. Results: 17 patients with Lyme disease showed sings of multisystem damage. The majority of them, accounting for 70.59%, was nervous system diseases called neuroborreliosis, which were

  16. Thermal stability in exchange-spring chains of spins

    Science.gov (United States)

    Pellicelli, Raffaele; Solzi, Massimo

    2016-02-01

    Thermal stability and switching behaviour have been compared in pure-hard and soft-hard Heisenberg linear spin chains of the same total length and equal magnetic parameters (except for magnetic anisotropy) with the anisotropy axis and external magnetic field parallel to the chain direction. The zero-temperature energy barriers and finite-temperature transition rates between remanent equilibrium states have been calculated by utilizing the string method and the forward flux sampling (FFS) method, respectively. Depending on the assumed interfaces, the FFS method could in fact fail to correctly sample the characteristic transition paths at interfaces at which these paths have probabilities much lower than those associated with other non-characteristic transition paths. This can especially occur in the case of the asymmetric energy landscapes and multiple asymmetric minimum energy paths (MEPs) of soft-hard systems. Therefore, a proper interface definition is needed in order to deduce the correct transition rates. In particular, we show that the thermal switching of soft-hard chains starting in the soft or in the hard part turns out to occur with an equal rate provided that the interfaces of the FFS method are defined on the basis of the corresponding zero-temperature MEPs. The thermal stability of a soft-hard chain in the remanent equilibrium state could be to some extent lower with respect to that of a pure-hard chain, due to the shorter hard-part length crossed by the domain wall formed in the chain and also to the related slightly smaller energy barrier. However, its switching field at zero temperature is verified to be widely lower than that of the pure-hard chain. Analytical expressions of switching fields and energy barriers have been deduced in various cases.

  17. Thermal stability in exchange-spring chains of spins

    International Nuclear Information System (INIS)

    Thermal stability and switching behaviour have been compared in pure-hard and soft–hard Heisenberg linear spin chains of the same total length and equal magnetic parameters (except for magnetic anisotropy) with the anisotropy axis and external magnetic field parallel to the chain direction. The zero-temperature energy barriers and finite-temperature transition rates between remanent equilibrium states have been calculated by utilizing the string method and the forward flux sampling (FFS) method, respectively. Depending on the assumed interfaces, the FFS method could in fact fail to correctly sample the characteristic transition paths at interfaces at which these paths have probabilities much lower than those associated with other non-characteristic transition paths. This can especially occur in the case of the asymmetric energy landscapes and multiple asymmetric minimum energy paths (MEPs) of soft–hard systems. Therefore, a proper interface definition is needed in order to deduce the correct transition rates. In particular, we show that the thermal switching of soft–hard chains starting in the soft or in the hard part turns out to occur with an equal rate provided that the interfaces of the FFS method are defined on the basis of the corresponding zero-temperature MEPs. The thermal stability of a soft–hard chain in the remanent equilibrium state could be to some extent lower with respect to that of a pure-hard chain, due to the shorter hard-part length crossed by the domain wall formed in the chain and also to the related slightly smaller energy barrier. However, its switching field at zero temperature is verified to be widely lower than that of the pure-hard chain. Analytical expressions of switching fields and energy barriers have been deduced in various cases. (paper)

  18. Digital Microfluidics Sample Analyzer

    Science.gov (United States)

    Pollack, Michael G.; Srinivasan, Vijay; Eckhardt, Allen; Paik, Philip Y.; Sudarsan, Arjun; Shenderov, Alex; Hua, Zhishan; Pamula, Vamsee K.

    2010-01-01

    Three innovations address the needs of the medical world with regard to microfluidic manipulation and testing of physiological samples in ways that can benefit point-of-care needs for patients such as premature infants, for which drawing of blood for continuous tests can be life-threatening in their own right, and for expedited results. A chip with sample injection elements, reservoirs (and waste), droplet formation structures, fluidic pathways, mixing areas, and optical detection sites, was fabricated to test the various components of the microfluidic platform, both individually and in integrated fashion. The droplet control system permits a user to control droplet microactuator system functions, such as droplet operations and detector operations. Also, the programming system allows a user to develop software routines for controlling droplet microactuator system functions, such as droplet operations and detector operations. A chip is incorporated into the system with a controller, a detector, input and output devices, and software. A novel filler fluid formulation is used for the transport of droplets with high protein concentrations. Novel assemblies for detection of photons from an on-chip droplet are present, as well as novel systems for conducting various assays, such as immunoassays and PCR (polymerase chain reaction). The lab-on-a-chip (a.k.a., lab-on-a-printed-circuit board) processes physiological samples and comprises a system for automated, multi-analyte measurements using sub-microliter samples of human serum. The invention also relates to a diagnostic chip and system including the chip that performs many of the routine operations of a central labbased chemistry analyzer, integrating, for example, colorimetric assays (e.g., for proteins), chemiluminescence/fluorescence assays (e.g., for enzymes, electrolytes, and gases), and/or conductometric assays (e.g., for hematocrit on plasma and whole blood) on a single chip platform.

  19. Supply Chains and Social Network Analysis

    OpenAIRE

    Mueller, Rolf A.E.; Buergelt, Doreen; Seidel-Lass, Linda

    2008-01-01

    Judged by its currency, the supply chain is one of the more successful metaphors in economics. The metaphor borrows from mechanics the idea of the chain, that is something that consists of elements that are linked to each of their two immediate neighbors and which jointly provide a strong but flexible connection. The metaphor transplants the chain-idea into the sphere of economics where, before the introduction of supply chains, chains were, for most economists, things best left in the care o...

  20. SUPPLY CHAIN MANAGEMENT – KEY FACTORS

    OpenAIRE

    Magdalena Daniela DINU

    2014-01-01

    This paper exposes Supply Chain Management by its key factors. Briefly, where the Supply Chain Management is treated as strategic part of a company then maintaining both control and influence throughout the entire supply chain are key factors and critical to success. On the other hand, finding the right partner to manage the non-strategic Supply Chains would be another key factor too. To define the most important key factors within Supply Chain Management means a deeply understanding of bot...

  1. Information flow in the pharmaceutical supply chain

    OpenAIRE

    Yousefi, Nazila; Alibabaei, Ahmad

    2015-01-01

    Managing the supply chain plays an important role in creating competitive advantages for companies. Adequate information flow in supply chain is one of the most important issues in SCM. Therefore, using certain Information Systems can have a significant role in managing and integrating data and information within the supply chain. Pharmaceutical supply chain is more complex than many other supply chains, in the sense that it can affect social and political perspectives. On the other hand, man...

  2. OVERVIEW OF CHINESE CHAIN CATERING MARKET

    OpenAIRE

    Wang, Yiting

    2012-01-01

    This thesis is a market overview for chain catering business situation in China. Chinese chain catering market is developing rapidly in recent years, it is a business where everybody can become a customer, but the business is highly competitive. The subject of this thesis is to give an overview of the market situation and strategies for market expansion of Chinese chain catering industry. It contains knowledge of chain management and introduction of Chinese chain catering ma...

  3. Supply chain management and optimization in manufacturing

    CERN Document Server

    Pirim, Harun; Yilbas, Bekir Sami

    2014-01-01

    This book introduces general supply chain terminology particularly for novice readers, state of the art supply chain management and optimization issues and problems in manufacturing. The book provides insights for making supply chain decisions, planning and scheduling through supply chain network. It introduces optimization problems, i.e. transportation of raw materials, products and location, inventory of plants, warehouses and retailers, faced throughout the supply chain network.

  4. Ontological Supply Chain Management: Concepts, Applications, Extensions

    OpenAIRE

    Ilter, H. Kemal

    2013-01-01

    SCOM: Multi-Layer Ontological Model for Supply Chain Systems© aims to create a model for tracking and tracing products, agents, flows and operations of a supply chain with an upper ontology.  It will hopefully let us to track or trace most properties in not-usual supply chains such as interstellar supply chains (eg. raw materials from the planet Mars), health-related supply chains (eg. blood products), food management (eg. genetic structures of agricultural products), envir...

  5. Research on Integrated Green Supply Chain Management

    Institute of Scientific and Technical Information of China (English)

    DENG Lei; WANG Xu

    2006-01-01

    On the basis of the analyzing product life cycle and value chain management in green supply chain, integrated green supply chain is put forward and constructed which involve lean production, agile manufacturing and green supply chain. This integrated structure provides an effective method for resolving some questions such as cost, market, environment, etc. in enterprise. A case study is presented at the end of paper to demonstrate how integrated supply chain implemented successfully in enterprise.

  6. Sustainability Analysis for Gayo Coffee Supply Chain

    OpenAIRE

    Rachman Jaya; Machfud Machfud; Sapta Raharja; Marimin Marimin

    2013-01-01

    Sustainable supply chain is a development of the conventional supply chains that discuses trade-off among economic, social and environmental dimensions in order to achieve better responsiveness in terms of quality, quantity and time-delivery in the supply chain structure. The objective of this research was to determine the Gayo coffee supply chain sustainability. The research was conducted at Bener Meriah and Aceh Tengah Districts, Aceh Province, Indonesia. Key actors in the supply chain cons...

  7. MRSA CC398 in the pig production chain.

    Science.gov (United States)

    Broens, E M; Graat, E A M; van der Wolf, P J; van de Giessen, A W; van Duijkeren, E; Wagenaar, J A; van Nes, A; Mevius, D J; de Jong, M C M

    2011-02-01

    In 2005, a distinct clone of methicillin resistant Staphylococcus aureus (MRSA CC398) was found in pigs and people in contact with pigs. The structure of the pig production chain in high technology pig husbandry enables pathogens to spread during animal trading, with an increasing prevalence in herds further down the chain. The objective of this study was to quantify the effect of the MRSA status of the supplying herd on the MRSA status of the receiving herd in order to gain more insight into the role of animal trading as a transmission route for MRSA CC398. Nasal samples (60-80 pigs per herd) were collected from 38 herds; in 20 herds, environmental samples were collected as well. Ten MRSA-positive herds (based on the results of nasal swabs of 10 individual pigs per herd) from a prior study were included in the data analysis. Herds were classified as MRSA positive if at least one sample tested positive. The 48 herds were part of 14 complete (40 herds) and 4 incomplete (8 herds) pig production chains. Fifty-six percent of the herds were classified as MRSA positive. MRSA-positive herds were observed at the start (breeding herds), middle (farrowing herds) and the end (finishing herds) of the pig production chain. All of the herds in 8 chains tested MRSA positive;, all of the herds in 5 chains tested MRSA negative and in the remaining 5 chains, MRSA-positive and MRSA-negative herds were detected. Seven spa types were found, which were all previously confirmed to belong to CC398. All of the isolates were susceptible to mupirocin, linezolid, rifampicin, fusidic acid and cotrimoxazole. Resistance against tetracycline, erythromycin and clindamycin was found in 100, 74 and 76% of the isolates, respectively. Seventy-nine percent of herds with a MRSA-positive supplier of pigs were MRSA positive, whereas 23% of herds with a MRSA-negative supplier were MRSA positive (OR=10.8; 95% CI: 1.5-110.1; P=0.011). The presence of entirely MRSA-positive and MRSA-negative chains and the

  8. Novette chain design and performance

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, J.T.; Speck, D.R.

    1980-12-11

    The design and performance of the Novette laser system, which is a two-beam, two-wavelength (1.05 ..mu.. and 0.53 ..mu..) target irradiation facility using phosphate glass laser chains, are discussed with information on the glass properties, controlling factors in the design selection, and projected performance with varying operating conditions. (LCL)

  9. Novette chain design and performance

    International Nuclear Information System (INIS)

    The design and performance of the Novette laser system, which is a two-beam, two-wavelength (1.05 μ and 0.53 μ) target irradiation facility using phosphate glass laser chains, are discussed with information on the glass properties, controlling factors in the design selection, and projected performance with varying operating conditions

  10. The design of supply chains

    DEFF Research Database (Denmark)

    Bøge Sørensen, Lars

    2004-01-01

    the existing literature. Describes the conceptexternal specificity and how it's used to design supply chains. Using the concept upstream,archetypes of risk minimal and maximal design are identified. Downstream the conceptdescribes two viable scenarios, one minimizing the impact, the other minimizing...

  11. What Shapes Food Value Chains?

    DEFF Research Database (Denmark)

    Jespersen, Karen Sau; Kelling, Ingrid; Ponte, Stefano;

    2014-01-01

    In this article, we explain what shapes food value chains through the analysis of selected aquaculture industries in four key Asian producing countries. Worldwide production of aquatic resources has grown rapidly in the past few decades, and aquaculture production in Asia has played a decisive ro...

  12. Smallest Nanoelectronics with Adatom Chains

    Science.gov (United States)

    Yamada, Toshishige; Saini, Subhash (Technical Monitor)

    1998-01-01

    This viewgraph presentation is focused on the general aspect of atomic chain electronics that I have been studying. Results have been published before, but are being rederived here using a new physical/mathematical picture/model, which deepens the physical understanding. Precise adatom structures can be used as a template on a regulated surface with no uncertainty.

  13. Preisdifferenzierung im Supply Chain Management

    OpenAIRE

    Koppers, Laura

    2010-01-01

    In the field of marketing, pricing is a valuable and long-established steering tool. But in the logistics context of co-operative strategies like supply chain management, this field is mainly neglected. Therefore, the author describes the basic principles and effects of price differentiation and suggests some further research regarding pricing in SCM considerations as well as co-operative pricing concepts.

  14. Supply Chain Management: een overzicht

    NARCIS (Netherlands)

    Schuring, R.W.

    2012-01-01

    De laatste jaren wordt voor het managen van het netwerk van bedrijven die betrokken zijn bij het tot stand komen van producten of diensten het woord Supply Chain Management, ook wel SCM, gebruikt. SCM wordt als term vooral in grote industrieën gebruikt. Bijna ieder bedrijf heeft echter een toelevern

  15. Discrete breathers in polyethylene chain

    OpenAIRE

    Savin, A. V.; Manevitch, L. I.

    2002-01-01

    The existence of discrete breathers (DBs), or intrinsic localized modes (localized periodic oscillations of transzigzag) is shown. In the localization region periodic contraction-extension of valence C-C bonds occurs which is accompanied by decrease-increase of valence angles. It is shown that the breathers present in thermalized chain and their contribution dependent on temperature has been revealed.

  16. A Markov Chain Estimator of Multivariate Volatility from High Frequency Data

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Horel, Guillaume; Lunde, Asger; Archakov, Ilya

    We introduce a multivariate estimator of financial volatility that is based on the theory of Markov chains. The Markov chain framework takes advantage of the discreteness of high-frequency returns. We study the finite sample properties of the estimation in a simulation study and apply it to...

  17. New Freeform Manufacturing Chains Based on Atmospheric Plasma Jet Machining

    Science.gov (United States)

    Arnold, T.; Boehm, G.; Paetzelt, H.

    2016-01-01

    New manufacturing chains for precise fabrication of asphere and freeform optical surfaces including atmospheric Plasma Jet Machining (PJM) technology will be presented. PJM is based on deterministic plasma-assisted material removal. It has the potential for flexible and cost-efficient shape generation and correction of small and medium-sized optical freeform elements. The paper discusses the interactions between the plasma tools and optical fused silica samples in the context of the pre-machined and intermediate surface states and identifies several plasma jet machining methods for freeform generation, surface correction, and finishing as well as suitable auxiliary polishing methods. The successful application of either processing chain is demonstrated.

  18. Improving supply chain collaborations and performance of inefficient supply chain

    OpenAIRE

    M. Sanei; S. Mamizadeh-Chatghayeh

    2010-01-01

    Modern manufacturing enterprises are required to collaborate by their business partners through their business process operations such as design, manufacture, distribution, and aftersales services. And furthermore performance evaluation is of great importance for effective supply chain man agement. Therefore, DEA can help companies to remove some of the in efficiencies in operational processes in order to become more effective. The current paper develops one approach for determining the DEA p...

  19. Supply Chain Management Performance in Tourism. Continental Hotels Chain Case

    OpenAIRE

    Gabriela Ţigu; Bogdan Călăreţu

    2013-01-01

    With its origins in logistics, Supply Chain Management (SCM) concept is covering all managerial aspects of the flow of materials and information from source to customer, across the entire range of materials handling and movement functions, and throughout an organization and its supply channels. In tourism, these issues relate to the whole process of providing tourism services from sourcing of raw materials, products or different services) to supply and distribution, and SCM performance can ul...

  20. What is a Responsible Supply Chain?

    Directory of Open Access Journals (Sweden)

    Terje Ingebrigt Vaaland

    2012-02-01

    Full Text Available The paper introduces the concept of responsible supply chain based on two dimensions, the core processes of a supply chain and the concept of corporate social responsibility (CSR. It is suggested that a responsible supply chain is achieved through manifested core values of the supply chain actors, strategies, and tactics. The paper further discusses the individual supply chain actors’ responsibility in securing a responsible supply chain beyond the actors’ direct control. A conceptual model and a definition of a responsible supply chain are offered. Our model not only provides structure to the extant research but also develops new constructs and relationships that improve the conceptualization of the responsible supply chain. The paper is based on a review of 81 research articles published between 2000 and 2010 in which elements of CSR and supply chain processes are included.

  1. Dynamics of Single Chains of Suspended Ferrofluid Particles

    Science.gov (United States)

    Cutillas, S.; Liu, J.

    1999-01-01

    . Therefore, only motions in this plane are probed. A very dilute sample of a ferrofluid emulsion with a particle volume fraction of 10(exp -5) is used in this experiment. We chose such a low volume fraction to avoid multiple light scattering as well as lateral chain-chain aggregation. DLS measures the dynamic structure factor S(q,t) of the sample (q is the scattering wave vector, t is the time). In the absence of the magnetic field, identical particles of ferrofluid droplets are randomly distributed and S(q,t) reduces to exp(-q(exp 2)2D(sub 0)t). D(sub 0)=(kT/(6(pi)(eta)(a)) is the diffusion coefficient of Brownian particles (where Xi = (6(pi)(eta)(a)) is the Stokes frictional coefficient of a spherical particle in a fluid of viscosity eta). If interactions or polydispersity can not be ignored, an effective diffusion coefficient is introduced. Formally, D(sub eff) is defined as: D(sub eff) = - q(exp -2) partial derivative of (ln(S(q,t)) with respect to time, as t goes to 0. D(sub eff) reduces to D(sub 0) if no interactions and only a few particles size are present. Therefore, we can use DLS to measure particle size. The particle radius was found to be a=0.23 mu m with 7% of polydispersity. In this case, if we vary the scattering angle theta (and so q) we do not have any change in the measured diffusion coefficient: it is q-independent. When a magnetic field is applied, particles aggregate into chains if lambda > 1. We first studied the kinetics of the chain formation when lambda = 406. At a fixed scattering angle, we measured diffusion coefficient D(sub eff) as a function of time. Experimentally, we find that D(sub eff) decreases monotonously with time. Physically, this means that chains are becoming longer and longer. Since we are only sensitive to motions in the scattering plane and since chains have their main axis perpendicular to this plane, the measured diffusion coefficient is the trans-verse diffusion coefficient. We can relate D(sub eff) to the mean number of

  2. chains

    Directory of Open Access Journals (Sweden)

    Gabriel Pérez-Salas

    2015-01-01

    Full Text Available Las barreras y aranceles al comercio exterior han disminuido significativamente gracias a los acuerdos multilaterales y los mecanismos de integración entre las naciones. Los costos logísticos representan una proporción significativa del precio final de los artículos, especialmente de los commodities. Por esta razón, minimizar los costos logísticos es un desafío importante para las naciones para fomentar la competitividad del comercio exterior y en particular para aprovechar la renta de los recursos naturales. En este artículo, proponemos un marco de referencia integral para la medición de costos logísticos, enfocado en determinar los extra-costos que resultan por procedimientos ineficientes y la falta de políticas públicas y regulaciones de las entidades públicas. Estos elementos no han sido considerados en la literatura, y este artículo aborda esta brecha. Como caso de estudio, presentamos la aplicación del marco de referencia para estimar los extra-costos en algunas cadenas logísticas de recursos naturales en Bolivia. Se presenta una discusión de los resultados encontrados, así como recomendaciones para trabajo futuro.

  3. Price adjustments by a gasoline retail chain

    International Nuclear Information System (INIS)

    We use daily data to examine price responses in the Swedish gasoline market to changes in the Rotterdam spot price, exchange rates and taxes. The distribution of price adjustments by a leading retail chain, for the period January 1980 to December 1996, is symmetric with no small adjustments. An error correction model shows that, in the short run, prices gradually move towards the long-run equilibrium in response to cost shocks. There is some evidence that, also in the short run, prices are stickier downwards than upwards. Prices respond more rapidly to exchange rate movements than to the spot market price. Our analysis emphasizes that to fully understand price adjustments it is necessary to examine data sets where the sample frequency at least matches that of price adjustments

  4. Den teoretiske udvikling af Supply Chain Strategimodeller

    DEFF Research Database (Denmark)

    Arvad Johansen, Jens

    2011-01-01

    segmentering via postponement-princippet, har givet mærkbare forbedringer. Det beskrives endvidere, hvordan produkternes livscyklus påvirker valget af supply chain design. Begrebet Demand Chain Management( DCM), hvormed strategimodeller bruger klassiske marketingelementer sammen med Supply Chain Management......Denne artikel beskriver med udgangspunkt i artikler og virksomhedseksempler udviklingen inde for supply chain strategimodeller. Ved hjælp af tidligere udviklede koncepter besvares spørgsmålet: “Hvad er den rette supply chain for mine produkter?”. Virksomhedseksempler beskriver, hvordan supply chain...... (SCM), bliver behandlet og der udvikles en DCM-strategimodel....

  5. The chain relation in sofic subshifts

    CERN Document Server

    Kazda, Alexandr

    2009-01-01

    The paper gives a characterisation of the chain relation of a sofic subshift. Every sofic subshift $\\Sigma$ can be described by a labelled graph $G$. Factorising $G$ in a suitable way we obtain the graph $G/_\\approx$ that offers insight into some properties of the original subshift. Using $G/_\\approx$ we describe first the chain relation in $\\Sigma$, then characterise chain-transitive sofic subshifts, chain-mixing sofic subshifts and finally the attractors of the subshift dynamic system. At the end we present (straightforward) algorithms deciding chain-transitivity and chain-mixing properties of a sofic subshift and listing all the attractors of the subshift system.

  6. Actinobaculum suis Detection Using Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Cristina Román Amigo

    2012-01-01

    Full Text Available Actinobaculum suis is an important agent related to urinary infection in swine females. Due to its fastidious growth characteristics, the isolation of this anaerobic bacterium is difficult, thus impairing the estimation of its prevalence. The purpose of this study was to develop and test a polymerase chain reaction (PCR for the detection and identification of A. suis and then compare these results with traditional isolation methods. Bacterial isolation and PCR were performed on one hundred and ninety-two urine samples from sows and forty-five preputial swabs from boars. The results indicate that this PCR was specific for A. suis, presenting a detection limit between 1.0×101 CFU/mL and 1.0×102 CFU/mL. A. suis frequencies, as measured by PCR, were 8.9% (17/192 in sow urine samples and 82.2% (37/45 in preputial swabs. Assessed using conventional culturing techniques, none of the urine samples were positive for A. suis; however, A. suis was detected in 31.1% (14/45 of the swabs. This PCR technique was shown to be an efficient method for the detection of A. suis in urine and preputial swabs.

  7. INTERNATIONALIZATION OF BRAZILIAN FRANCHISE CHAINS: A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Pedro Lucas de Resende Melo

    2015-04-01

    Full Text Available The primary goal of this paper is to comprehend the fundamental organizational differences between Brazilian franchise chains that only operate in the home market and Brazilian franchise chains that operate internationally. The sample chosen for this study comprehends 96 Brazilian franchises operating in the home market and 67 franchises with international operations; logistic regression was used to analyze data obtained from these sources. Our findings suggest that the development of a brand in international operations can be strategic for certain Brazilian franchise chains; this seems to be, however, a scarce resource for many franchises and it could be developed through international operations. With regard to the fees charged, the outcomes demonstrate that Brazilian franchises with international operations tend to charge lower fees from its franchisees to install new units. Regarding the monitoring and control of franchises, there is evidence that the monitoring capability is one of the determining factors in the development of Brazilian franchises international operations.

  8. Supply Chain Reorganization and Coordination

    Institute of Scientific and Technical Information of China (English)

    WANG Feng-bin

    2001-01-01

    Three generic forms of governance--hierarchy, hybrid and market are proposed in the newinstitutional economics, giving an abstract description of alternative coordination and control mechanisms forgeneral use. While this theory is known as far away from being operational and specified, a few researchersin the management and organization area are trying to extend Galbraith and/or Mintzberg's organizationaldesign theories into the application of logistical coordination for obtaining a smooth flow of products along thesupply chain within and without the focal organization. In this paper, we present an explorative case study onthe design of various organizational architectures of logistics activities and their relevant coordinationmechanisms, especially internal and external contracts as one new kind of hybrid mechanisms forcoordinating effective supply chains.

  9. Labour in Global Value Chains

    DEFF Research Database (Denmark)

    Lund-Thomsen, Peter; Nadvi, Khalid; Chan, Anita;

    2012-01-01

    A critical challenge facing developing country producers is to meet international labour standards and codes of conduct in order to engage in global value chains. Evidence of gains for workers from compliance with such standards and codes remains limited and patchy. This article focuses on the...... draws on detailed qualitative primary field research with football-stitching workers and producers in these three countries. The article explains how and why work conditions of football stitchers differ across these locations through an analytical framework that interweaves both global and local...... global football industry, a sector dominated by leading global brands that manage dispersed global value chains. It assesses the working conditions for football stitchers engaged in different forms of work organization, factories, stitching centres and home-based settings in Pakistan, India and China. It...

  10. Supply Chain Simulation: A Survey

    OpenAIRE

    Kleijnen, J.P.C.

    2003-01-01

    This paper provides a survey of simulation in supply chain management.It reviews four types of simulation, namely spreadsheet simulation, system dynamics, discreteevent simulation, and business games.Which simulation type should be applied, depends on the type of managerial question to be answered by the model.Moreover, this paper summarizes novel sensitivity and robustness analyses.This sensitivity analysis yields a shortlist of the truly important factors in large simulation models with (sa...

  11. Tunnel magnetoresistance of polymeric chains

    OpenAIRE

    Walczak, Kamil

    2004-01-01

    Coherent spin-dependent electronic transport is investigated in a molecular junction made of polymeric chain attached to ferromagnetic electrodes (Ni and Co, respectively). Molecular system is described by a simple Huckel model, while the coupling to the electrodes is treated through the use of a broad-band theory. The current flowing through the device is calculated within non-equilibrium Green's function approach. It is shown that tunnel magnetoresistance of molecular junction can be quite ...

  12. China's Role in Purchasing Chain

    Institute of Scientific and Technical Information of China (English)

    Eva; Alice

    2007-01-01

    @@ In current world market,"Made-in-China"often means good price and competitive quality.In terms of China's trade pattern,more than half of Chinese exporting products belong to processing trade industry according to the demands and requirements of international orders.On the purchasing chain,China is learning from its international partners.Safety and quality always tops all issues.

  13. Organizing the Global Value Chain

    OpenAIRE

    Pol Antràs; Davin Chor

    2012-01-01

    We develop a property-rights model of the firm in which production entails a continuum of uniquely sequenced stages. In each stage, a final-good producer contracts with a distinct supplier for the procurement of a customized stage-specific component. Our model yields a sharp characterization for the optimal allocation of ownership rights along the value chain. We show that the incentive to integrate suppliers varies systematically with the relative position (upstream versus downstream) at whi...

  14. Spin Chain for Quantum Strings

    OpenAIRE

    Beisert, N.

    2005-01-01

    We review and compare the integrable structures in N=4 gauge theory and string theory on AdS5xS5. Recently, Bethe ansaetze for gauge theory/weak coupling and string theory/strong coupling were proposed to describe scaling dimensions in the su(2) subsector. Here we investigate the Bethe equations for quantum string theory, naively extrapolated to weak coupling. Excitingly, we find a spin chain Hamiltonian similar, but not equal, to the gauge theory dilatation operator.

  15. Demand and Supply Chain Management

    OpenAIRE

    Jack A.A. van der Veenl:; Robben, Henry S.J.

    1999-01-01

    In dit artikel wordt ingegaan op de recente ontwikkelingen met be-trekking tot de managementactiviteiten gericht op de keten die begint bij het winnen van grondstoffen en via toeleveranciers, fabrikanten en de (detail)handel loopt naar de eindgebruikers. De moderne denkbeelden op dit terrein worden samengevat met de term Demand & Supply Chain Management (DSCM); het management van de keten die onafhankelijke klanten en leveranciers verbindt als ware het een enkele en-titeit met het doel om waa...

  16. The Milk Supply Chain Project.

    OpenAIRE

    Smith, Howard; Thanassoulis, John

    2008-01-01

    This report presents the results of an Oxford University research project into the UK liquid milk supply chain. Financial sponsorship was kindly provided by the Milk Development Council (MDC) and by DEFRA. The research reported here is independent academic research which is not designed to further any group‟s particular agenda. We have striven to be as objective as possible. The project's aim is to investigate the competitive forces which influence the buyerseller relationsh...

  17. On Markov Chains and Filtrations

    OpenAIRE

    Spreij, Peter

    1997-01-01

    In this paper we rederive some well known results for continuous time Markov processes that live on a finite state space.Martingale techniques are used throughout the paper. Special attention is paid to the construction of a continuous timeMarkov process, when we start from a discrete time Markov chain. The Markov property here holds with respect tofiltrations that need not be minimal.

  18. Supply Chain Performance Evaluation: Trends and Challenges

    Directory of Open Access Journals (Sweden)

    Ezutah U. Olugu

    2009-01-01

    Full Text Available Problem statement: In today’s manufacturing world, globalization policies and rejuvenation have created a more intensive competition amongst manufacturers. On the other hand, manufacturers have turned to the option of adopting innovative technologies, process re-engineering and strategies such as efficient supply chain management to achieve a sustainable competitive advantage. Effective supply chain performance measurement has been identified as a key issue towards efficient supply chain management. To explore the extent of research in supply chain performance measurement and establish the gap in knowledge in supply chain performance measurement using fuzzy logic operation. Approach: Literatures in the area of supply chain performance measurement had been extensively reviewed. Both traditional and fuzzy logic approaches to supply chain performance measurement were scrutinized. Further scrutiny was carried out to establish potential research areas in the application of fuzzy logic operations in supply chain performance measurement. Results: The supply chain performance measurement using fuzzy logic operation was identified as a new direction in measuring the uncertainty and ambiguity surrounding supply chain performance measurement. Direction for further studies in the application of fuzzy logic operation in supply chain management and its performance measurement were also identified. Conclusion: Result of this study implied that there is still a gap in knowledge in the area of supply chain performance measurement. This new direction of studies involved extending the existing supply chains to incorporate product recovery after the useful life.

  19. ARCHITECTURAL CONCEPTS FOR VALUE CHAINS

    Directory of Open Access Journals (Sweden)

    A.C. Janse van Rensburg

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT:The Porter Value Chain has been widely adopted by the business community as a mechanism to understand and comprehend complexity in business environments, with the ultimate goal of structuring the business to maximize its competitive advantage. Implementing the Value Chain is not easy: a number of organizations can testify to their failure to derive any benefits at all from this concept. To overcome this problem, an approach is presented to assist the organization in creating a Value Chain reference model within the broader context of the organization’s enterprise architecture.

    AFRIKAANSE OPSOMMING: Die “Porter Waardeketting” is ’n algemene aanvaarde praktyk wat deur maatskappye gebruik word om die kompleksiteit van besigheidsomgewings mee te verstaan. Die uiteindelike doel hiervan is om die besigheid se mededings voordele te optimiseer. Om die Waardekettingkonsep te implementeer, is nie ’n maklike taak nie – verskeie organisasies kan getuig van mislukte implementeringspogings. Hierdie artikel beskryf ’n benadering beskryf wat gebruik kan word om die organisasie te help om ’n Waardekettingmodel te skep in die bree konteks van die organisasie se besigheidsargitektuur.

  20. on Guinea Pig Tracheal Chains

    Directory of Open Access Journals (Sweden)

    Rana Keyhanmanesh

    2013-02-01

    Full Text Available   Objective(s: In regard to the high incidence of asthma and the side-effects of the drugs used, finding novel treatments for this disease is necessary. Our previous studies demonstrated the preventive effect of Nigella sativa extract on ovalbumin-induced asthma. In addition, water-soluble substances of N. sativa extract and methanol fraction of this plant were responsible for the relaxant effect of this plant on tracheal chains of guinea pigs. Therefore, for the first time, in the present study, in order to identify main constituents of the methanolic extract, the relaxant effects of five different methanolic fractions (20%, 40%, 60%, 80%, and 100% of N. sativa   on tracheal chains of guinea pigs were examined.     Materials and Methods:     The relaxant effects of four cumulative concentrations of each fraction (0.8, 1.2, 1.6, and 2.0 g% in comparison with saline as negative control and four cumulative concentrations of theophylline (0.2, 0.4, 0.6, and 0.8 mM were examined by their relaxant effects on precontracted tracheal chains of guinea pig by 60 mM KCl (group 1 and 10 μM methacholine (group 2.     Results: In group 1, all concentrations of only theophylline showed significant relaxant effects but all concentrations of these methanolic fractions showed significant contractile effects compared with that of saline (P

  1. Natural radioactivity in food chains

    International Nuclear Information System (INIS)

    A number of longliving and still being produced radioactive isotopes produces well measurable and not to be neglected radiation, by which, via the food chains, plant, animal and man receives a socalled natural radiation dose. Six of the most important isotopes are discussed here. The radioisotopes 14C and 40K form part of the most live-necessary elements; they pass without strong enrichment and discrimination through the food chains and form a practically constant part of the living organism. Yet by excessive fertilizing a rather higher content of potassium than necessary is present in plants. Also a higher radiation dose arises from exessive uptake of food. The isotopes of uranium 238U and radium, 226Ra, discussed here, occur everywhere in the soil, but locally in very high amounts. They migrate for a very small part into plant and animal, sometimes occur in vegetable food as part of soil particles. Other important isotopes of the uranium families are radioactive lead, 210Pb, and polonium, 210Po, which can be dispersed to a much greater amount than the other isotopes: in the form of the gaseous intermediate product radon, here the isotope 222Rn. 210Pb and 210Po are finally deposited upon plants and other food products. In the hydrosphere 210Po can be enriched in the food chain from plankton to fish. (author). 35 refs.; 2 figs.; 3 tabs

  2. Limitations of clonality analysis of B cell proliferations using CDR3 polymerase chain reaction

    OpenAIRE

    Hoeve, M A; Krol, A D G; Philippo, K; Derksen, P W B; Veenendaal, R. A.; Schuuring, E; Kluin, Ph M; Krieken, J.H.J.M. van

    2000-01-01

    Background/Aims—Detection of clonal immunoglobulin heavy chain (IgH) rearrangements by the polymerase chain reaction (PCR) is an attractive alternative to Southern blotting in lymphoma diagnostics. However, the advantages and limitations of PCR in clonality analysis are still not fully appreciated. In this study, clonality was analysed by means of PCR, focusing in particular on the sample size requirements when studying extremely small samples of polyclonal and monoclonal lesions.

  3. Hepatitis E Virus in Pork Food Chain, United Kingdom, 2009–2010

    OpenAIRE

    Berto, Alessandra; Martelli, Francesca; Grierson, Sylvia; Banks, Malcolm

    2012-01-01

    We investigated contamination by hepatitis E virus (HEV) in the pork production chain in the United Kingdom. We detected HEV in pig liver samples in a slaughterhouse, in surface samples from a processing plant, and in pork sausages and surface samples at point of sale. Our findings provide evidence for possible foodborne transmission of HEV during pork production.

  4. Detection of adenovirus hexon sequence in a cat by polymerase chain reaction(short communication)

    NARCIS (Netherlands)

    Horzinek, M.C.; Lakatos, B.; Farkas, J.; Egberink, H.F.; Vennema, H.; Benko, M.

    1999-01-01

    Adenoviral nucleic acid was detected by polymerase chain reaction (PCR) in pharyngeal and rectal swab samples of a cat seropositive for adenovirus and suffering from transient hepatic failure. The samples were taken at a one-year interval, and both faecal samples as well as the second pharyngeal sam

  5. The Impact of Risks in Supply Chain on Organizational Performances: Evidence from Romania

    Directory of Open Access Journals (Sweden)

    Gyula Laszlo FLORIAN

    2014-12-01

    Full Text Available The proposed empirical research uses a national sample of 64 Romanian companies from various industries to document the relationship between organizational performances and risks in the context of Romanian supply chains. Empirical findings show that a supply chain risk management strategy successfully mitigates the negative consequences of risks. Our research underlines the changes necessary to maximize the benefits of supply chain integration. To extend the knowledge in this area our research is interdisciplinary, using a structural approach to model the determinants of organizational performances in supply chains and to measure the complex relationships among risks in supply chains and different facets of organizational performances in the context of Romanian supply chains.

  6. Determinants of Supply Chain Performance of Indian Manufacturing Organizations

    Directory of Open Access Journals (Sweden)

    Amit Kumar Marwah

    2014-02-01

    Full Text Available This paper aims at proposing various determinants of supply chain performance of Indian manufacturing organizations. The determinants are summarized based on extensive literature review of empirical research articles on supply chain management (SCM and performance measurement approaches. This study is a part of a larger research project exploring SC related practices. A critical analysis is carried out so as to identify research gaps in context of performance measurement of supply chains, as well as to propose directions for future research. A conceptual model is also proposed. Critical investigation of selected articles led to an idea that there can be significant effect of selected variables on SC Performance. It is to be seen that how various parameters, taken from the literature review, affect SC performance and ultimately contributing to its competitiveness. The various parameters like supplier-buyer relations, external supply chain, environmental factors, human metrics, information sharing and performance measurement approaches are taken in a single study in the context of Indian manufacturing organizations. Based on a pilot study with sample size of 100, empirical tests resulted in reduction of items. Based on the obtained results, the organizations can enhance the SCM performance by improving the current practices/strategies through focusing on the determinants that significantly influence SCM performance. Further research can be carried out by using data of various supply chains of other sectors and industries of India to generalize the research.

  7. Synthesis and Properties of Dendritic Long-Chain Esters as Crude Oil Flow Improver Additives

    Institute of Scientific and Technical Information of China (English)

    Li Cuiqin; Sun Peng; Shi Weiguang; Wang Jun

    2016-01-01

    The efifciencies of 6 kinds of macromolecules with dendritic structure in improving the lfow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amidoamine) and alkyl long-chain acrylic esters as starting materials, and their structures were characterized by the Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental analysis. The effects on the pour point and rheological properties of crude oil samples were studied. Efifciencies of dendritic long-chain esters were not only inlfuenced by the alky chain length, but also by the generation of dendrimer. The longer the alkyl chain of dendritic long-chain ester was, the better the effect in the reduction of pour point and apparent viscosity was. Efifciencies of 1.5 generation dendritic long-chain ester with 8 branched chains for the reduction of pour point and apparent viscosity were superior to those of 0.5 generation dendritic long-chain ester with 4 branched chains. Under the same conditions, efifciencies of 1.5 generation dendritic eighteen ester were superior to those of other 1.5 generation dendritic long-chain esters for the reduction of pour point and viscosity of crude oil.

  8. Transition Probability Estimates for Reversible Markov Chains

    OpenAIRE

    Telcs, Andras

    2000-01-01

    This paper provides transition probability estimates of transient reversible Markov chains. The key condition of the result is the spatial symmetry and polynomial decay of the Green's function of the chain.

  9. Information flow in the pharmaceutical supply chain.

    Science.gov (United States)

    Yousefi, Nazila; Alibabaei, Ahmad

    2015-01-01

    Managing the supply chain plays an important role in creating competitive advantages for companies. Adequate information flow in supply chain is one of the most important issues in SCM. Therefore, using certain Information Systems can have a significant role in managing and integrating data and information within the supply chain. Pharmaceutical supply chain is more complex than many other supply chains, in the sense that it can affect social and political perspectives. On the other hand, managing the pharmaceutical supply chain is difficult because of its complexity and also government regulations in this field. Although, Iran has progressed a lot in pharmaceutical manufacturing, still there are many unsolved issues in managing the information flow in the pharmaceutical supply chain. In this study, we reviewed the benefits of using different levels of an integrated information system in the supply chain and the possible challenges ahead. PMID:26664401

  10. SUPPLY CHAIN MANAGEMENT – KEY FACTORS

    Directory of Open Access Journals (Sweden)

    Magdalena Daniela DINU

    2014-06-01

    Full Text Available This paper exposes Supply Chain Management by its key factors. Briefly, where the Supply Chain Management is treated as strategic part of a company then maintaining both control and influence throughout the entire supply chain are key factors and critical to success. On the other hand, finding the right partner to manage the non-strategic Supply Chains would be another key factor too. To define the most important key factors within Supply Chain Management means a deeply understanding of both Supply Chain’ s components, procedures, workflow, processes and the importance of Supply Chain Management into maximizing company's value. SCORE model able to provide solid information about measuring performance and identifying priorities within Supply Chain Management will help us to understand the key factors by analyzing its elements: Plan, Source, Make, Deliver,Return, Enable. These elements covers all the challenging areas from first to third tier of Supply Chain Management.

  11. Polymerization as a Model Chain Reaction

    Science.gov (United States)

    Morton, Maurice

    1973-01-01

    Describes the features of the free radical, anionic, and cationic mechanisms of chain addition polymerization. Indicates that the nature of chain reactions can be best taught through the study of macromolecules. (CC)

  12. Supply chain strategies, issues and models

    CERN Document Server

    Ramanathan, Ramakrishnan

    2014-01-01

    In the 21st century, supply chain operations and relationships among supply chain partners have become highly challenging, necessitating new approaches, e.g., the development of new models. Supply Chain Strategies, Issues and Models discusses supply chain issues and models with examples from actual industrial cases. Expert authors with a wide spectrum of knowledge working in various areas of supply chain management from various geographical locations offer refreshing, novel and insightful ideas and address possible solutions using established theories and models. Supply Chain Strategies, Issues and Models features studies that have used mathematical modeling, statistical analyses and also descriptive qualitative studies. The chapters cover many relevant themes related to supply chains and logistics including supply chain complexity, information sharing, quality (six sigma), electronic Kanbans, inventory models, scheduling, purchasing and contracts. To facilitate easy reading, the chapters that deal with suppl...

  13. Chain Networks as a Leverage for Innovation Capacity: The Case of Food SMEs

    Directory of Open Access Journals (Sweden)

    Bianka Kühne

    2011-02-01

    Full Text Available  Nowadays, innovation is no longer limited to the individual firm but involves increasingly the chain network in which the firm is embedded. The chain network is considered as the place where the internal and external resources of a firm are combined and transformed, leading to innovation capacity. In the increasingly globalizing market, innovation is an important strategic tool for small and medium sized enterprises (SMEs to achieve competitive advantage. However, SMEs are often confronted with barriers for developing and introducing innovations, such as the lack of economies of scale. Our paper investigates how the chain network is contributing to the enhancement of the innovation capacity and which chain network characteristics are crucial in this process. In contrast to previous studies at chain network level, in our research specific chain networks are investigated and compared to each other. Hence, data collection took place at different chain network levels, being the supplier, the food manufacturer and the customer, working together and consequently belonging to one specific and unique chain network.The analysis of innovation capacity at the chain network level is realized by means of cluster analysis. This results in a three-cluster solution dividing the sample into Non-innovator chain networks, Customer-driven innovator chain networks and food manufacturer-supplier-driven innovator chain networks. Next, the influence of the chain network on the innovation capacity is examined. Thereby, the three achieved clusters differ significantly related to certain chain network characteristics. The following characteristics form an important leverage for the innovation capacity: firm size, profitability and business growth of the chain network members, as well as higher dependency, and lower levels of integration, rewarding power, social satisfaction and collaboration. The distinction of Customer-driven and food manufacturer

  14. Benchmarking carbon emissions performance in supply chains

    OpenAIRE

    Acquaye, Adolf; Genovese, Andrea; Barrett, John W.; Koh, Lenny

    2014-01-01

    Purpose – The paper aims to develop a benchmarking framework to address issues such as supply chain complexity and visibility, geographical differences and non-standardized data, ensuring that the entire supply chain environmental impact (in terms of carbon) and resource use for all tiers, including domestic and import flows, are evaluated. Benchmarking has become an important issue in supply chain management practice. However, challenges such as supply chain complexity and visibility, geogra...

  15. Supply Chain Integration: Challenges and Solutions

    OpenAIRE

    Sweeney, Edward

    2011-01-01

    Rapid changes in technological development are forcing businesses to continuously innovate to improve their competitiveness, which is particularly evident in logistics and supply chain management (SCM), where innovation impacts both the strategic and operational levels. Supply Chain Innovation for Competing in Highly Dynamic Markets: Challenges and Solutions investigates the role of innovation in the management of supply chains of today. This book focuses on supply chain integration from both...

  16. Supply chain management in product development.

    OpenAIRE

    Tzortzopoulos, Patricia; Kagioglou, Mike; Cooper, Rachel; Dyson, E

    2009-01-01

    Mounting emphasis on construction supply chain management (CSCM) is due to both global sourcing of materials and a shortage of labor. These factors force increasing amounts of value-added work to be conducted off-site deep in the supply chain. Construction Supply Chain Management Handbookcompiles in one comprehensive source an overview of the diverse research and examples of construction supply chain practice around the world.Reflecting the emergence of CSCM as an important area of multi-nati...

  17. Model protocells from single-chain lipids.

    Science.gov (United States)

    Mansy, Sheref S

    2009-03-01

    Significant progress has been made in the construction of laboratory models of protocells. Most frequently the developed vesicle systems utilize single-chain lipids rather than the double-chain lipids typically found in biological membranes. Although single-chain lipids yield less robust vesicles, their dynamic characteristics are highly exploitable for protocellular functions. Herein the advantages of using single-chain lipids in the construction of protocells are discussed. PMID:19399223

  18. BUSINESS TENDENCIES IN SERVICES WITHIN SUPPLY CHAIN

    OpenAIRE

    Beata Skowron-Grabowska

    2008-01-01

    Supply chain management has been a major component of competitive strategy to enhance organizational productivity and profitability. Client satisfaction and improvement in profitability are two basic goals while organizing supply chain. In the paper author tried to prove that there is a correlation between organization of supply chain and subjective evaluation of economic situation by enterprises. Logistics integration helps enterprises to find their place in the supply chain.

  19. Analysis of a quantum Markov chain

    International Nuclear Information System (INIS)

    A quantum chain is analogous to a classical stationary Markov chain except that the probability measure is replaced by a complex amplitude measure and the transition probability matrix is replaced by a transition amplitude matrix. After considering the general situation, we study a particular example of a quantum chain whose transition amplitude matrix has the form of a Dirichlet matrix. Such matrices generate a discrete analog of the usual continuum Feynman amplitude. We then compute the probability distribution for these quantum chains

  20. Australian Lamb Supply Chain: A Conceptual Framework

    OpenAIRE

    Jie, Ferry

    2011-01-01

    In the last decade, supply chain management has played an important role to lead agribusiness today to succeed in their business goals, to gain competitive advantages, and to improve business performance. As the result of that, there has been extensive studying in a popular topic of strategic supply chain management in order to improve business performance as well as along supply chain performance under the real situation. This is because in current business world, supply chain practices are ...

  1. Kooperationsanforderungen im Supply Chain Management (SCM)

    OpenAIRE

    Klumpp, Matthias; Koppers, Laura

    2007-01-01

    In this paper the general concept of Supply Chain Management (SCM) is described and the scientific cooperation models in the supply chain are discussed. Though there are several models to explain cooperations there is no clear perspective on the needed competencies in companies to shape a successful cooperation e.g. within a supply chain. Instead companies rely solely on experience and intuition in order to create and steer supply chain relationships with high business values. In order to mit...

  2. Supply Chain Differentiation : Background, Concept and Examples

    OpenAIRE

    Hofmann, Erik; Knébel, Stephan

    2016-01-01

    The purpose of this paper is to provide new evidence in the field of supply chain differentiation. It aims to combine insights of supply chain management with the service dominant logic to connect fundamental customer requirements with supply chain decision-making. The paper claims to provide a framework that brings together the most relevant factors in the context of supply chain differentiation. The contents of the framework were applied as source to develop a generic decision support flowc...

  3. Green Supply Chains: An Indian Perspective

    OpenAIRE

    Dani, Samir

    2011-01-01

    In today’s business environment global supply chains have to deal with the complexities of sourcing, logistics and costs. In order to keep costs down, supply chains are long and thus have to deal with complex inventory management challenges. Another challenge faced by supply chains is that of being environmentally friendly or green. As the discussion regarding climate change gathers momentum, the supply chains will be held under scrutiny for carbon emissions and use of fuel. Green supply chai...

  4. Supply Chain Management in the Construction Industry

    OpenAIRE

    Olsson, Fredrik

    2000-01-01

    In this licentiate thesis the implications of a deliberate use of logistics knowledge have been investigated by describing and analyzing the use of a supply chain management approach in the construction industry.
    A five-step approach is used in the thesis. First, theoretical models are developed from the supply chain management literature. Two models are elaborated; One model identifying supply chain criteria and the other comparing traditional to supply chain-based.

  5. Model Protocells from Single-Chain Lipids

    OpenAIRE

    Mansy, Sheref S.

    2009-01-01

    Significant progress has been made in the construction of laboratory models of protocells. Most frequently the developed vesicle systems utilize single-chain lipids rather than the double-chain lipids typically found in biological membranes. Although single-chain lipids yield less robust vesicles, their dynamic characteristics are highly exploitable for protocellular functions. Herein the advantages of using single-chain lipids in the construction of protocells are discussed.

  6. Model Protocells from Single-Chain Lipids

    Directory of Open Access Journals (Sweden)

    Sheref S. Mansy

    2009-03-01

    Full Text Available Significant progress has been made in the construction of laboratory models of protocells. Most frequently the developed vesicle systems utilize single-chain lipids rather than the double-chain lipids typically found in biological membranes. Although single-chain lipids yield less robust vesicles, their dynamic characteristics are highly exploitable for protocellular functions. Herein the advantages of using single-chain lipids in the construction of protocells are discussed.

  7. Trade in Value Chain of Food Products

    OpenAIRE

    Zdenko Segetlija

    2008-01-01

    The paper sets out from the definition of the value chain upon which follows the analysis of the value chain structure ih the food sector. Special attention is paid to market forms in the food sector (competition, agreements, oligopolistic constellation and the like). After that, modern form of cooperation in the value chain are started (supply chain management - SCM, efficient consumer response – ECR, and other). In this context the role of wholesale and that of retail trade in the food prod...

  8. A concept for collaborative supply chain planning

    DEFF Research Database (Denmark)

    Alfnes, E.; Dreyer, H.C.; Hvolby, Hans-Henrik;

    2012-01-01

    The main challenge for many manufacturers is the increased complexity of the supply chain, and as supply chains get more complicated enterprises require better tools for supply chain planning and execution. Many vendors offer systems to plan and control in-house operations, whereas mainly large v...... discusses current supply chain planning solutions and presents a more simple and adaptive concept to be used in both SMEs and larger enterprises....

  9. Magnetic Properties of Quantum Ferrimagnetic Spin Chains

    OpenAIRE

    Yamamoto, Shoji

    1998-01-01

    Magnetic susceptibilities of spin-$(S,s)$ ferrimagnetic Heisenberg chains are numerically investigated. It is argued how the ferromagnetic and antiferromagnetic features of quantum ferrimagnets are exhibited as functions of $(S,s)$. Spin-$(S,s)$ ferrimagnetic chains behave like combinations of spin-$(S-s)$ ferromagnetic and spin-$(2s)$ antiferromagnetic chains provided $S=2s$.

  10. Systematic Methodology of Integrated Supply Chain Management

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Supply chain management (SCM) is a strategy for global competition. Th e characteristics of SCM are integration, systematic and coordination. Using sys tematic, coordination thoughts and integration theory, a new model of enterprise integration based on supply chain management is put forward and an implementing paradigm for systematic methodology of supply chain management is developed.

  11. On a Result for Finite Markov Chains

    Science.gov (United States)

    Kulathinal, Sangita; Ghosh, Lagnojita

    2006-01-01

    In an undergraduate course on stochastic processes, Markov chains are discussed in great detail. Textbooks on stochastic processes provide interesting properties of finite Markov chains. This note discusses one such property regarding the number of steps in which a state is reachable or accessible from another state in a finite Markov chain with M…

  12. The Evolutionary Dynamics of Biofuel Value Chains

    DEFF Research Database (Denmark)

    Ponte, Stefano

    2014-01-01

    In this paper I propose to push the frontier of global value chain (GVC) governance analysis through the concept of ‘polarity’. Much of the existing GVC literature has focused on ‘unipolar’ value chains, where one group of ‘lead firms’ inhabiting a specific function in a chain plays a dominant ro...

  13. Visualisation for System Learning in Supply Chains

    Science.gov (United States)

    Lindskog, Magnus; Abrahamsson, Mats; Aronsson, Hakan

    2007-01-01

    Contemporary supply chains are vastly complex, and decisions made by actors have system-wide consequences that these might not be able to foresee. There are gaps between "best practice"-founded theory and actual practice in supply chains. To remedy this, we argue, the supply chain actors need to enhance systems knowledge. There is a need to…

  14. Learning to Integrate: Supply Chains Reconceptualised

    Science.gov (United States)

    Sense, Andrew J.; Clements, Michael D. J.

    2007-01-01

    This paper introduces and explains a conception of supply chains from a situated learning perspective. This non-conventional supply chain perspective invites the reader to consider supply chain scenarios as "situated learning opportunities involving multiple communities of practice" interacting and participating together. It is argued that by…

  15. Principles in Halal Supply Chain Management

    NARCIS (Netherlands)

    Tieman, H.; Vorst, van der J.G.A.J.; Maznah Che Ghazali,

    2012-01-01

    Purpose – The purpose of this paper is to introduce a new framework to optimise the design of halal food supply chains, called the “Halal Supply Chain Model”. In this research the main logistics business processes are defined, which are the determinants for the halal supply chain performance. Design

  16. Extending the "Knowledge Advantage": Creating Learning Chains

    Science.gov (United States)

    Maqsood, Tayyab; Walker, Derek; Finegan, Andrew

    2007-01-01

    Purpose: The purpose of this paper is to develop a synergy between the approaches of knowledge management in a learning organisation and supply chain management so that learning chains can be created in order to unleash innovation and creativity by managing knowledge in supply chains. Design/methodology/approach: Through extensive literature…

  17. Compressing redundant information in Markov chains

    OpenAIRE

    Aletti, Giacomo

    2006-01-01

    Given a strongly stationary Markov chain and a finite set of stopping rules, we prove the existence of a polynomial algorithm which projects the Markov chain onto a minimal Markov chain without redundant information. Markov complexity is hence defined and tested on some classical problems.

  18. Supply Chain Management Performance in Tourism. Continental Hotels Chain Case

    Directory of Open Access Journals (Sweden)

    Gabriela Ţigu

    2013-02-01

    Full Text Available With its origins in logistics, Supply Chain Management (SCM concept is covering all managerial aspects of the flow of materials and information from source to customer, across the entire range of materials handling and movement functions, and throughout an organization and its supply channels. In tourism, these issues relate to the whole process of providing tourism services from sourcing of raw materials, products or different services to supply and distribution, and SCM performance can ultimately be measured by customer satisfaction. Thus, an important component of tourism SCM is the demand management. Therefore, this study aims to highlight the features of the concept of SCM and demand management in tourism, with an emphasis on a hotel chain in Romania, based on research and analysis of tourist traffic indicators as well as assessment of customers satisfaction. The sources of information are the internal company statistics, as well as various hotels booking websites that offer customers’ feedback. The results of the study provide a snapshot of how the hotel demand management can influence SCM performance in tourism.

  19. MODELING SUPPLY CHAIN WITH SIMULATION

    OpenAIRE

    János Benkõ

    2010-01-01

    Supply Chain Management faces a lot of challenging issues involving difficult decisions which can be company-oriented and customer-oriented issues. In this study we deal with customeroriented issues. For example, a customer’s demand may not be fully satisfied from stock on hand and the shortage may be backordered or the sale may be lost. Either way, it is desirable to balance the holding cost which depends on the magnitude of inventory against the cost of not fully satisfying customer demand....

  20. Supply chain management - safety aspects

    Directory of Open Access Journals (Sweden)

    2010-12-01

    Full Text Available Developing economy, growing customer requirements and competition make the service level higher. Delivery safety - as the highest priority - has to be maintained at the same time. Customers more and more often require transport to be very flexible, fast, and complex in terms of carrying every quantity of goods of different sizes, from and to different countries, through customs clearance, storing and distribution of shipments. Meeting these requirements depends on complex information on transport processes and their safety. The article presents safety foundations and institution Authorized Economic Operator - AEO in supply chains.

  1. Compressibility of Nickel Nanoparticle Chain

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Dong; TANG Ling-Yun; LI Yan-Chun; LIU Jing

    2007-01-01

    We perform the high-pressure energy dispersive x-ray diffraction experiments of nickel nanoparticle chain using a synchrotron source under quasi-hydrostatic compression up to 44.7GPa. There is no phase transition over the pressure range. The bulk modulus Kg, the first pressure derivative of bulk modulus K'0 and the volume Vo are calculated from the pressure-volume data using the Birch-Murnaghan equation of state. A decrease of compressibility is observed, in agreement with the Hall-Petch effect.

  2. What Can Healthcare Supply Chains Learn from Consumer-Product Supply Chains?

    OpenAIRE

    Leroy B. Schwarz

    2008-01-01

    A Framework for Thinking About Supply-Chain Management: “The IDIB Portfolio” (Information, Decision-making, Implementation, Buffer system) Describe Supply-Chains for Consumer Products Before “Wal-Mart” Describe Supply-Chains for Consumer Products After “Wal-Mart” Describe Stylized Supply Chain for Healthcare Products

  3. Integration of Forestry Industrial Chain in China

    Institute of Scientific and Technical Information of China (English)

    Zhanzhan; LAN; Liqun; WANG

    2013-01-01

    Based on the Smile Curve and Michael E. Porter’ value chain model,this paper points out that China’s forestry industry stays at the low end of the value chain for a long time. Raw materials are imported from foreign countries and also sold in foreign countries. Then,the authors analyze characteristics and existing problems of China’s forestry industrial chain. They put forward the development direction of China’s forestry industrial chain with reference to International Paper Company. Finally,they present their recommendations for integration of China’s forestry industrial chain.

  4. Maintaining Power Relations in Supply Chain

    OpenAIRE

    Ibishukcu, Ozlem; Datar, Aniket

    2016-01-01

    Managing supply chain relations has evolved over a decade and many companies have given importance to regulate their relations in supply chain relations to stay competitive in the market. In this context of adjusting relations among supply chain members, central point of discussion is the role of power. Power can be a component that persuades one member of supply chain to do certain things that he/she wouldn’t agree on doing it voluntarily. The implication of that power among supply chain mem...

  5. Cellular chain formation in Escherichia coli biofilms

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk; Klemm, Per

    2009-01-01

    In this study we report on a novel structural phenotype in Escherichia coli biofilms: cellular chain formation. Biofilm chaining in E. coli K-12 was found to occur primarily by clonal expansion, but was not due to filamentous growth. Rather, chain formation was the result of intercellular......; type I fimbriae expression significantly reduced cellular chain formation, presumably by steric hindrance. Cellular chain formation did not appear to be specific to E coli K-12. Although many urinary tract infection (UTI) isolates were found to form rather homogeneous, flat biofilms, three isolates...

  6. The role of enterprise systems in supply chain networks: a taxonomy of supply chain strategies

    DEFF Research Database (Denmark)

    Møller, Charles

    2006-01-01

    supply chain and to choose the right supply chain strategy. The work is based on a comprehensive study of the Supply Chain Management (SCM) and Enterprise Resource Planning (ERP) literature and the study suggests that there is an emerging new research potential for Enterprise Systems (ES) in the supply......This paper proposes a taxonomy for supply chain integration strategies. The taxonomy is based on the contingencies of supply chain network coupling and the Extended Enterprise Systems (EES) architecture in the supply chain. The purpose of this model is to map the portfolio of relations in the...... chain....

  7. Chain store management through private labels strategy

    Directory of Open Access Journals (Sweden)

    Martina Sopta

    2007-07-01

    Full Text Available The purpose of this paper is to examine the market shares of private labels in the European Union and on the global market, and to compare the results of the analysis with the level of presence of private labels on the Croatian market. Moreover, through the application of macro and microeconomic tools, the author tried to estimate the future trends of private labels in Croatia.For the purpose of the paper secondary and primary data was used in the research. Relevant scientific and professional literature of local and foreign authors was analyzed. In addition, a few recent research studies were analyzed and their results compared. Field research has been conducted by the survey method, with 225 respondents included in the intentional sample.The main hypothesis of the paper based on research is that, in total sales, private labels are gaining a growing share in all markets, regardless of the development level of those markets. Alongside the main hypothesis of the work, three supporting hypotheses were tested to see which private labels are a good alternative to other brands on the world market. Private labels are generally developed on generic products. The third supporting hypothesis starts from the assumption that the investments in the promotion of private labels are negligible, resulting in lower prices of thoseproducts. The results of research and analyses in the work indicate that the position of private labels will strengthen internationally, as part of the process of liberalization and globalization of trade flows. In the process of purchase of private labels the positioning of the point of sale and price have an increasing contribution. With the concentration of commerce in chain stores, the share of private labels grows, approaching a half of the total sales in some countries. Considering the Croatian market, according to the international product life cycle theory, the share of private labels in the total sales will grow in the future

  8. Parallel Markov Chain Monte Carlo via Spectral Clustering

    OpenAIRE

    Basse, Guillaume W.; Pillai, Natesh S.; Smith, Aaron

    2016-01-01

    As it has become common to use many computer cores in routine applications, finding good ways to parallelize popular algorithms has become increasingly important. In this paper, we present a parallelization scheme for Markov chain Monte Carlo (MCMC) methods based on spectral clustering of the underlying state space, generalizing earlier work on parallelization of MCMC methods by state space partitioning. We show empirically that this approach speeds up MCMC sampling for multimodal distributio...

  9. Kinematics and Dynamics of Roller Chain Drives

    DEFF Research Database (Denmark)

    Fuglede, Niels

    There are two main subjects of this work: Kinematic and dynamic modeling and analysis of roller chain drives. In the kinematic analysis we contribute first with a complete treatment of the roller chain drive modeled as a four-bar mechanism. This includes a general, exact and approximate analysis...... parameters which is useful for predicting the characteristic loading of the roller chain drive. As a completely novel contribution, a kinematic model and analysis is presented which includes both spans and sprockets in a simple chain drive system. A general procedure for determination of the total wrapping...... conditions for real chain drives. Examples are presented of both decoupled and coupled motion. Together, the kinematic and dynamic model and analytical results provides a framework for numerical and experimental investigations of roller chain drive motion and deepens the understanding of roller chain drive...

  10. Determining an optimal supply chain strategy

    Directory of Open Access Journals (Sweden)

    Intaher M. Ambe

    2012-11-01

    Full Text Available In today’s business environment, many companies want to become efficient and flexible, but have struggled, in part, because they have not been able to formulate optimal supply chain strategies. Often this is as a result of insufficient knowledge about the costs involved in maintaining supply chains and the impact of the supply chain on their operations. Hence, these companies find it difficult to manufacture at a competitive cost and respond quickly and reliably to market demand. Mismatched strategies are the root cause of the problems that plague supply chains, and supply-chain strategies based on a one-size-fits-all strategy often fail. The purpose of this article is to suggest instruments to determine an optimal supply chain strategy. This article, which is conceptual in nature, provides a review of current supply chain strategies and suggests a framework for determining an optimal strategy.

  11. The fish industry - toward supply chain modelling

    DEFF Research Database (Denmark)

    Jensen, Toke Koldborg; Nielsen, Jette; Larsen, Erling;

    2010-01-01

    Mathematical models for simulating and optimizing aspects of supply chains such as distribution, planning, and optimal handling of raw materials are widely used. However, modeling based on a holistic chain view including several or all supply chain agents is less studied, and food-related aspects...... step toward innovative supply chain modeling aimed to identify benefits for all agents along chains in the fish industry....... such as quality and shelf-life issues enforce additional requirements onto the chains. In this article, we consider the supply chain structure of the fish industry. We discuss and illustrate the potential of using mathematical models to identify quality and value-adding activities. The article provides a first...

  12. Two Cases of Heavy Chain MGUS.

    Science.gov (United States)

    Van Keer, Jan; Meijers, Björn; Delforge, Michel; Verhoef, Gregor; Poesen, Koen

    2016-01-01

    Heavy chain diseases are rare variants of B-cell lymphomas that produce one of three classes of immunoglobulin heavy chains, without corresponding light chains. We describe two patients with asymptomatic heavy chain monoclonal gammopathy. The first patient is a 51-year-old woman with alpha paraprotein on serum immunofixation. The second case is a 46-year-old woman with gamma paraprotein on urine immunofixation. Neither patient had corresponding monoclonal light chains. Workup for multiple myeloma and lymphoma was negative in both patients. These two cases illustrate that heavy chain monoclonal gammopathy can exist in the absence of clinically apparent malignancy. Only a few reports of "heavy chain MGUS" have been described before. In the absence of specialized guidelines, we suggest a similar follow-up as for MGUS, while taking into account the higher probability of progression to lymphoma than to myeloma. PMID:27213064

  13. Two Cases of Heavy Chain MGUS

    Directory of Open Access Journals (Sweden)

    Jan Van Keer

    2016-01-01

    Full Text Available Heavy chain diseases are rare variants of B-cell lymphomas that produce one of three classes of immunoglobulin heavy chains, without corresponding light chains. We describe two patients with asymptomatic heavy chain monoclonal gammopathy. The first patient is a 51-year-old woman with alpha paraprotein on serum immunofixation. The second case is a 46-year-old woman with gamma paraprotein on urine immunofixation. Neither patient had corresponding monoclonal light chains. Workup for multiple myeloma and lymphoma was negative in both patients. These two cases illustrate that heavy chain monoclonal gammopathy can exist in the absence of clinically apparent malignancy. Only a few reports of “heavy chain MGUS” have been described before. In the absence of specialized guidelines, we suggest a similar follow-up as for MGUS, while taking into account the higher probability of progression to lymphoma than to myeloma.

  14. Sustainability Analysis for Gayo Coffee Supply Chain

    Directory of Open Access Journals (Sweden)

    Rachman Jaya

    2013-01-01

    Full Text Available Sustainable supply chain is a development of the conventional supply chains that discuses trade-off among economic, social and environmental dimensions in order to achieve better responsiveness in terms of quality, quantity and time-delivery in the supply chain structure. The objective of this research was to determine the Gayo coffee supply chain sustainability. The research was conducted at Bener Meriah and Aceh Tengah Districts, Aceh Province, Indonesia. Key actors in the supply chain considered were farmers, collectors, agro-industry and exporter. Sustainability dimensions considered in this research were the economic, social, environmental and material resources. The performance of each aspect was analyzed by using Multi-dimensional scaling and leverage analysis. The result of the research showed that the composite of Gayo coffee supply chain sustainability index was 33.53 which mean less sustainable level. Therefore it is recommended to reengineering the Gayo coffee supply chain by considering all of the four sustainability dimensions above.

  15. PV supply chain growing pains

    International Nuclear Information System (INIS)

    This article discussed issues involving the supply chain for photovoltaic (PV) equipment that is emerging in Ontario as a result of the Feed-in-Tariff (FIT) program that was launched in late 2009. The rapidly developing PV supply chain may not be taking a sustainable path. The domestic-content requirement is making manufacturers outlay capital to set up manufacturing in Ontario without reliable market data. Only a small number of dealer/installers have any meaningful experience designing and installing grid-tie PV. Until recently, wholesale distributors designed and supplied most grid-tie PV systems in Canada, and solar dealers/installers or electricians or electrical contractors did the installation. Instead of selling directly to dealer/installers, solar manufacturers should develop strong relationships with wholesalers, who have system design experience and product training. This would allow manufacturers to focus on their core strength, reach more customers, and keep lower inventory levels. Wholesale distributors in turn provide dealer/installers with expertise in product and system design, training from a range of manufacturers, marketing and logistics support, and immediate access to inventory. Manufacturers generally lack appropriate accounting, engineering, marketing, and logistics services to deal with a multitude of active accounts, and they are not structured to work with architects and engineers to do complete system design. Partnering with wholesale distributors allows manufacturers to take on the residential and small-scale commercial sectors by building brand awareness and increasing market share and sales across Canada. 2 figs.

  16. Artificial radioisotopes in food chains

    International Nuclear Information System (INIS)

    Use of uranium for nuclear fission involves the risk of environmental contamination by radiation during the processes of mining, concentration, peaceful and military application and storage, reprocessing and waste disposal. Three of the most dangerous radioisotopes have been followed here as they move through four different food chains. The main bottlenecks for fast and massive transfer are for 131I its rather short half life, for 137Cs the defective plant uptake from soil (and much less so also the pathway through the animal body), and for 90Sr its discrimination relative to calcium in several transport processes in the animal body, and its preference for the bone mass. Hence it is often of advantage for man to use animals as an additional food chain. Known exceptions are discussed: the reindeer and karibou living entirely on lichens during the winter and thereby acquiring for 137Cs nearly identical specific activity as plant food, and cow's milk for iodine during a short period after contamination. 15 refs.; 1 figure; 4 tabs

  17. RS-markov Chain Model of Logistics Service Supply Chain based on Exploration Diagram

    OpenAIRE

    Shi Li; Shi Yu-Zhen

    2013-01-01

    In order to achieve the forecast evaluation of logistics service supply chain, a tool of system-thinking in complex scientific management-Exploration diagram, is used to establish the index system for the forecast evaluation of logistics service supply chain. And according to the significant Markov chain property in the operation of logistics service supply chain, the predictability of the Markov chain is used to put forward a dynamic evaluation model, example ...

  18. Challenges of locally manufactured vehicle supply chains in South Africa

    Directory of Open Access Journals (Sweden)

    Intaher M. Ambe

    2013-05-01

    Full Text Available Locally manufactured vehicles are destined (partly for the export market and thus, global competitiveness  is  important.  This  article  explores  the  challenges  facing  supply  chains  of locally manufactured vehicles in South Africa. The automotive industry is perceived to be the most advanced in supply chain management practices in South Africa. It has embraced technology and management practices that have transformed the manufacturing environment by using cutting-edge design and visualisation tools. However, the industry has fragilities and faces new and emerging supply chain challenges. A survey research design was employed and  the  data  was  collected  through  face-to-face  semi-structured  interview  questionnaires based on the purposive sampling technique. Data analysis and interpretation was based on descriptive  statistics  using  SPSS  software.  The  findings  revealed  that  there  are  challenges hindering  best  supply  chain  practices  of  local  vehicle  manufacturers.  The  research  also revealed that there is a perceived difference in supply chain challenges between the different manufacturers of different origins in South Africa. Asian manufacturers felt much stronger about the adequacy of their information systems compared to the European manufacturers. Asian  manufacturers  tended  to  agree  more  than  their  European  counterparts  that  labour problems were a challenge. European manufacturers, on the other hand, tended to agree more that rail transport is unreliable. This article contributes to the body of knowledge on supply chain practices in South Africa. 

  19. Dangling chain elastomers as repeatable fibrillar adhesives.

    Science.gov (United States)

    Sitti, Metin; Cusick, Brian; Aksak, Burak; Nese, Alper; Lee, Hyung-il; Dong, Hongchen; Kowalewski, Tomasz; Matyjaszewski, Krzysztof

    2009-10-01

    This work reports on repeatable adhesive materials prepared by controlled grafting of dangling hetero chains from polymer elastomers. The dangling chain elastomer system was prepared by grafting poly(n-butyl acrylate) (PBA) chains from prefunctionalized polydimethylsiloxane (PDMS) elastomer networks using atom transfer radical polymerization. To study the effects of chain growth and network strain as they relate to network adhesion mechanics, various lengths of PBA chains with degree of polymerizations (DP) of 65, 281, 508, and 1200 were incorporated into the PDMS matrix. PBA chains with a DP value of 281 grafted from a flat PDMS substrate showed the highest (approximately 3.5-fold) enhancement of nano- and macroscale adhesion relative to a flat raw (ungrafted and not prefunctionalized) PDMS substrate. Moreover, to study the effect of PBA dangling chains on adhesion in fibrillar elastomer structures inspired by gecko foot hairs, a dip-transfer fabrication method was used to graft PBA chains with a DP value of 296 from the tip endings of mushroom-shaped PDMS micropillars. A PBA chain covered micropillar array showed macroscale adhesion enhancement up to approximately 7 times relative to the flat ungrafted prefunctionalized PDMS control substrate, showing additional nonoptimized approximately 2-fold adhesion enhancement due to fibrillar structuring and mushroom-shaped tip ending. These dangling hetero chains on elastomer micro-/nanofibrillar structures may provide a novel fabrication platform for multilength scale, repeatable, and high-strength fibrillar adhesives inspired by gecko foot hairs. PMID:20355863

  20. Structure of polymer chains under confinement

    Indian Academy of Sciences (India)

    Jyotsana Lal

    2008-11-01

    We observe by SANS the structure of neutral polystyrene and charged polystyrene sulphonate chains in semi-dilute solutions confined in a model nanoporous glass, Vycor. The size of the free chains in solution is always larger than the pore diameter, 70. The use of a suitable mixture of hydrogenated and deuterated solvents and polymers enables us to measure directly the form factor of one single chain among the others. Single chain form factor was observed both for bulk and confined chains using the condition of zero average contrast. Our measurements on neutral polymer chains are in agreement with the theoretical predictions established by Daoud and de Gennes for chains confined in a cylindrical pore when the chains are entangled and laterally squeezed but remain ideal at large scale along the cylinder axis because of the screening of the excluded volume interactions (so-called regime of ``semi-dilute cigars"). For confined charged polymers, a peak is observed whose intensity increases with molecular weight and the asymptotic 1/ scattering region is extended compared to the bulk. We infer that the chains are sufficiently extended, under the influence of confinement, to highlight the large scale disordered structure of Vycor even under contrast matched conditions. The asymptotic behaviour of the observed interchain structure factor is ≈ 1/2 and ≈ 1/ for free and confined chains respectively.

  1. Phase behaviour of polyethylene knotted ring chains

    Institute of Scientific and Technical Information of China (English)

    Wen Xiao-Hui; Zhang Lin-Xi; Xia A-Gen; Chen Hong-Ping

    2011-01-01

    The phase behaviour of polyethylene knotted ring chains is investigated by using molecular dynamics simulations.In this paper, we focus on the collapse of the polyethylene knotted ring chain, and also present the results of linear and ring chains for comparison. At high temperatures, a fully extensive knot structure is observed. The mean-square radius of gyration per bond〈S2〉/(Nb2)and the shape factor(δ*)depend on not only the chain length but also the knot type.With temperature decreasing, chain collapse is observed, and the collapse temperature decreases with the chain length increasing. The actual collapse transition can be determined by the specific heat capacity Cv, and the knotted ring chain undergoes gas-liquid-solid-like transition directly. The phase transition of a knotted ring chain is only one-stage collapse, which is different from the polyethylene linear and ring chains. This investigation can provide some insights into the statistical properties of knotted polymer chains.

  2. A possible chain of motivation

    Directory of Open Access Journals (Sweden)

    Rodica Ianole

    2007-12-01

    Full Text Available On a world-wide basis there is a growing concern about organization' s capability to retain their top talents. In the specific case of a student's organization . Team Work - we confront with the same problems: how to inspire our members to act in the spirit of the values we share: professionalism, team work and voluntariate, and how to determine them to remain part of the system. This is where motivation appears like one of those terms that can mean very different things depending on exactly where you sit. The aim of the present paper is to draw a schematic picture of how it can work a chain of motivation in Team Work and other similar organizations.

  3. Revisiting Causality in Markov Chains

    CERN Document Server

    Shojaee, Abbas

    2016-01-01

    Identifying causal relationships is a key premise of scientific research. The growth of observational data in different disciplines along with the availability of machine learning methods offers the possibility of using an empirical approach to identifying potential causal relationships, to deepen our understandings of causal behavior and to build theories accordingly. Conventional methods of causality inference from observational data require a considerable length of time series data to capture cause-effect relationship. We find that potential causal relationships can be inferred from the composition of one step transition rates to and from an event. Also known as Markov chain, one step transition rates are a commonly available resource in different scientific disciplines. Here we introduce a simple, effective and computationally efficient method that we termed 'Causality Inference using Composition of Transitions CICT' to reveal causal structure with high accuracy. We characterize the differences in causes,...

  4. The stylohyoid chain: CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Uysal Ramadan, Selma, E-mail: uysalselma@yahoo.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Goekharman, Dilek, E-mail: gokharman@ttnet.net.t [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Kosar, Pinar, E-mail: pkosar@hotmail.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Kacar, Mahmut, E-mail: mkacar1961@gamil.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Kosar, Ugur, E-mail: ugurkosar@hotmail.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey)

    2010-09-15

    We aimed in this report to discuss the embryology, anatomy, theories of ossification and symptoms, clinical presentation, and diagnosis of the stylohyoid chain (SHC) variations, together with the role of radiographs, computed tomography (CT) and three-dimensional (3D)-CT in showing these variations. Because CT/3D-CT additionally facilitates visualization of the entire SHC with different axes, it is the most valuable method for establishing the relationship between the SHC and the surrounding tissue. SHC variation can be discovered during CT performed for indications other than ossified SHC. It is important to diagnose whether or not the SHC is ossified, since one of the treatment procedures in ossified SHC is total excision. If the clinician and radiologist are aware of these variations observed in the SHC, patients with vague symptoms may be spared unnecessary investigations and may be properly diagnosed earlier.

  5. THE SPATIAL DISTRIBUTION AND MOMENTS OF CIRCULAR FREELY JOINTED CHAIN

    Institute of Scientific and Technical Information of China (English)

    HAO Minghong

    1991-01-01

    The spatial distribution function and second moments of circular freely jointed chain are derived based on an analytical method. The circular Gauss chain, which is simple for long chains, is compared with the circular freely jointed chain, which is exact for short chains. It is shown that the Gauss chain model predicts a more compact configurational distribution than the exact freely jointed chain. The two chain models, however, become closer to each other when the chain length increases.It is found that the difference of the mean square radius of gyration calculated with these two chain models is a constant, independent of the chain length.

  6. Determination of backbone chain direction of PDA using FFM

    Science.gov (United States)

    Jo, Sadaharu; Okamoto, Kentaro; Takenaga, Mitsuru

    2010-01-01

    The effect of backbone chains on friction force was investigated on both Langmuir-Blodgett (LB) films of 10,12-heptacosadiynoic acid and the (0 1 0) surfaces of single crystals of 2,4-hexadiene-1,6-diol using friction force microscopy (FFM). It was observed that friction force decreased when the scanning direction was parallel to the [0 0 1] direction in both samples. Moreover, friction force decreased when the scanning direction was parallel to the crystallographic [1 0 2], [1 0 1], [1 0 0] and [1 0 1¯] directions in only the single crystals. For the LB films, the [0 0 1] direction corresponds to the backbone chain direction of 10,12-heptacosadiynoic acid. For the single crystals, both the [0 0 1] and [1 0 1] directions correspond to the backbone chain direction, and the [1 0 2], [1 0 0] and [1 0 1¯] directions correspond to the low-index crystallographic direction. In both the LB films and single crystals, the friction force was minimized when the directions of scanning and the backbone chain were parallel.

  7. Probability Sampling Method for a Hidden Population Using Respondent-Driven Sampling: Simulation for Cancer Survivors.

    Science.gov (United States)

    Jung, Minsoo

    2015-01-01

    When there is no sampling frame within a certain group or the group is concerned that making its population public would bring social stigma, we say the population is hidden. It is difficult to approach this kind of population survey-methodologically because the response rate is low and its members are not quite honest with their responses when probability sampling is used. The only alternative known to address the problems caused by previous methods such as snowball sampling is respondent-driven sampling (RDS), which was developed by Heckathorn and his colleagues. RDS is based on a Markov chain, and uses the social network information of the respondent. This characteristic allows for probability sampling when we survey a hidden population. We verified through computer simulation whether RDS can be used on a hidden population of cancer survivors. According to the simulation results of this thesis, the chain-referral sampling of RDS tends to minimize as the sample gets bigger, and it becomes stabilized as the wave progresses. Therefore, it shows that the final sample information can be completely independent from the initial seeds if a certain level of sample size is secured even if the initial seeds were selected through convenient sampling. Thus, RDS can be considered as an alternative which can improve upon both key informant sampling and ethnographic surveys, and it needs to be utilized for various cases domestically as well. PMID:26107223

  8. Position Paper on Intelligent Supply Chains

    DEFF Research Database (Denmark)

    Møller, Charles

    frame the concept of Intelligent Supply Chain and to establish an overall perspective based on information management. The claim made here is that the notion of the intelligent enterprise contributes with a new perspective on supply chain management that addresses the current challenges in an industrial...... development of intelligent supply chains. It is concluded that information management is critical to intelligent supply chains and a research agenda is outlined.......This paper is intended to present and to analyze the concept of the Intelligent Supply Chain (ISC). The purpose of the paper is to: 1) Clarify the concept of the intelligent supply chain; 2) Identify emerging research opportunities; and 3) Specify a research engagement model for further exploration...

  9. The Governance of Global Wealth Chains

    DEFF Research Database (Denmark)

    Seabrooke, Leonard; Wigan, Duncan

    This working paper creates a theoretical framework to explain how Global Wealth Chains are created, maintained, and governed. We draw upon different strands of literature, including scholarship in international political economy and economic geography on Global Value Chains, literature on finance......, and global-scale corporate tax avoidance.......) innovation capacities among suppliers of products used in wealth chains. We then differentiate five types of global value chain governance - market, modular, relational, captive, and hierarchy - which range from simple ‘off shelf’ products shielded from regulators by advantageous international tax laws to...... highly complex and flexible innovative financial products produced by large financial institutions and corporations. This paper highlights how Global Wealth Chains intersect with value chains and real economies, and provides three brief case studies on offshore shell companies, family property trusts...

  10. Toc Approach for Supply Chain Performance Enhancement

    Directory of Open Access Journals (Sweden)

    Brijesh Ainapur

    2011-12-01

    Full Text Available Field of Supply Chain Management witnessed rapid growth in recent past and proved to be a successful tool for organizations growth. Success of supply chain improvement initiative lies in selection of appropriate Key Performance Indicators (KPIs using best suitable supply chain framework. These KPI’s are to be measured, monitored and controlled with proper review mechanism. This study presents a methodology for identification of the constraint KPI from the supply chain metrics. Selection of the KPI’s is done using Supply Chain Operations Reference (SCOR framework. Analytical Hierarchy Process (AHP is used for decomposing the goal into micro level for analyzing and prioritizing KPIs. Subsequently, benchmarking study is carried by comparing foundry industry KPIs with global best practice industry average. Goal Programming function is formulated using AHP ratings and solved using WINQSB software. Finally Theory of Constraint (TOC management philosophy is applied for finding the constraints for supply chain performance enhancement.

  11. Sustainable Supply Chain Design: A Configurational Approach

    OpenAIRE

    S. Maryam Masoumik; Salwa Hanim Abdul-Rashid; Ezutah Udoncy Olugu; Raja Ariffin Raja Ghazilla

    2014-01-01

    Designing the right supply chain that meets the requirements of sustainable development is a significant challenge. Although there are a considerable number of studies on issues relating to sustainable supply chain design (SSCD) in terms of designing the practices, processes, and structures, they have rarely demonstrated how these components can be aligned to form an effective sustainable supply chain (SSC). Considering this gap in the literature, this study adopts the configurational approac...

  12. Ground states for nonuniform periodic Ising chains

    OpenAIRE

    Martínez-Garcilazo, J. P.; Ramírez, C.

    2014-01-01

    We give a generalization of Morita's works on ground states of Ising chains, for chains with a periodic structure with different spins, and distant neighbor interactions. The main assumption is translational invariance. The length of the irreducible blocks is a multiple of the period of the chain. In the case of parity invariance, it restricts the length in general only in the diatomic case. There are degenerated states and under certain circumstances there could be nonregular ground states. ...

  13. Supply Chain Performance Evaluation: Trends and Challenges

    OpenAIRE

    Ezutah U. Olugu; Kuan Y. Wong

    2009-01-01

    Problem statement: In todays manufacturing world, globalization policies and rejuvenation have created a more intensive competition amongst manufacturers. On the other hand, manufacturers have turned to the option of adopting innovative technologies, process re-engineering and strategies such as efficient supply chain management to achieve a sustainable competitive advantage. Effective supply chain performance measurement has been identified as a key issue towards efficient supply chain manag...

  14. Challenges of Responsible Supply Chain Management

    OpenAIRE

    Krisztina Szegedi; Károly Norbert Kerekes

    2012-01-01

    Many firms are increasing their focus on their Supply Chain as a strategic factor. This focus has primarily emphasized cost reducing and risk minimizing, although some proactive companies began to manage their supply chain in a responsible way several years ago. This paper provides a comprehensive review of the part of the Corporate Social Responsibility literature that introduces responsibility to the field of supply chain management; furthermore, it processes public documents and Internet s...

  15. Sustainability management in apparel & footwear supply chain

    OpenAIRE

    Cheng, Hau-chung; 鄭孝仲

    2014-01-01

    Self-regulatory Code of Conduct has widely been adopted by international brands to manage CSR issues in apparel and footwear supply chain for the last 2 decades. Increasingly, more apparel and footwear brands started to expand CSR scope to include environmental management in their supply chain. However, only very few international brands have disclosed their efforts on environmental management in their supply chain. This study aims to find out how apparel and footwear brands implement environ...

  16. Sustainability in Logistics and Supply Chain Management

    OpenAIRE

    2015-01-01

    The HICL-Conference celebrates its 10th anniversary, indicating major interest in the research fields of supply chain management and logistics. They are dedicated to make recommendations for new approaches and solutions that enable companies to cope with current and future challenges in supply chains and logistics. The second volume of the 2015 conference provides valuable insights into the highly relevant topic of sustainability in logistics and supply chains. Contributions concern ...

  17. Antecedents and Dimensions of Supply Chain Robustness

    OpenAIRE

    Durach, Christian F.; Wieland, Andreas; Machuca, Jose A.D.

    2015-01-01

    Purpose – The purpose of this paper is to provide groundwork for an emerging theory of supply chain robustness – which has been conceptualized as a dimension of supply chain resilience – through reviewing and synthesizing related yet disconnected studies. The paper develops a formal definition of supply chain robustness to build a framework that captures the dimensions, antecedents and moderators of the construct as discussed in the literature. Design/methodology/approach – The...

  18. Spectral methods for quantum Markov chains

    International Nuclear Information System (INIS)

    The aim of this project is to contribute to our understanding of quantum time evolutions, whereby we focus on quantum Markov chains. The latter constitute a natural generalization of the ubiquitous concept of a classical Markov chain to describe evolutions of quantum mechanical systems. We contribute to the theory of such processes by introducing novel methods that allow us to relate the eigenvalue spectrum of the transition map to convergence as well as stability properties of the Markov chain.

  19. Wear of conveyor chains with polymer rolls

    OpenAIRE

    Kerremans, Vincent; Rolly, Tom; DE BAETS, PATRICK; De Pauw, Jan; Sukumaran, Jacob; Perez Delgado, Yeczain

    2011-01-01

    Roller conveyor chains are common used to transport goods in production lines or assembly lines, such as pallets, cars or steel coils. They are sometimes used in severe environments, soiled with water, foreign particles, chemicals or other contaminants. Normal use will result in wear of the components of the chain which can lead to unexpected failure and costly production downtime. Today, few literature on the wear of conveyor chain is available and there are almost no reliable test-rigs to g...

  20. BEHAVIOURAL INSIGHTS INTO SUPPLY CHAIN RISK MANAGEMENT

    OpenAIRE

    Alexandra-Codruta Popescu (Bîzoi); Cristian-Gabriel Bîzoi

    2015-01-01

    Literature has focused largely on the field of supply chain risk management. Numerous risks occur within supply chain management. Until lately, behavioural risks (implying large amount of losses) have been neglected and considered not relevant. In this paper we provide an analysis of the importance of including behavioural research in logistics and supply chain risk management, what has been written so far and potential future research directions. Until now, literature on logistics and supply...

  1. Understanding Construction Supply Chains: An Alternative Interpretation

    OpenAIRE

    Vrijhoef, Ruben; Koskela, Lauri; Howell, Greg

    2001-01-01

    Much research work has assessed that construction is ineffective and many problems can be observed. Analysis of these problems has shown that a major part of them are supply chain problems, originating at the interfaces of different parties or functions. There have been several kinds of initiatives aiming at improvement and renewal of construction supply chains, but only few have a track record of consequent and significant successes. Here construction supply chains are approached from an alt...

  2. The Mitigation of Supply Chain Risk.

    OpenAIRE

    Wilding, Richard D.

    2007-01-01

    Supply Chain Risk Management is receiving increased attention in recent years. With events such as 9/11, the foot and mouth outbreak in Europe and hurricane Katrina all impacting on organisations and the global supply chains they are part of. Trends including the rapid growth in global sourcing and offshore manufacturing; the continued move to reduce the supplier base; industry consolidation and the centralisation of distribution all change the risk profile of supply chains ...

  3. 1D ferrimagnetism in homometallic chains

    OpenAIRE

    Coronado Miralles, Eugenio; Gómez García, Carlos José; Borrás Almenar, Juan José

    1990-01-01

    The magnetic properties of the cobalt zigzag chain Co(bpy)(NCS)2 (bpy=2,2′‐bipyridine) are discussed on the basis of an Ising‐chain model that takes into account alternating Landé factors. It is emphasized, for the first time, that a homometallic chain containing only one type of site can give rise to a 1D ferrimagneticlike behavior. ,

  4. Achieving Supply Chain Integration within Construction Industry

    OpenAIRE

    Peter McDermotti; Malik Khalfan

    2012-01-01

    The main driver behind the adoption of supply chain management (SCM) philosophy into the construction industry was the successes within other industry sectors. SCM can be defined as network of different organisations, linked upstream and downstream in a chain, aiming to produce quality and value in the services and products for the end consumers through integrated processes and activities. In order to achieve the optimised level of integration of the whole supply chain, the industry has respo...

  5. Supply chain management tools and methods

    OpenAIRE

    IVANOVA, Ivelina

    2004-01-01

    In today's business environment, manufacturers need to manage their enterprises as an inseparable part of a supply chain. Key to achieving this is the creation of an extended and integrated information system. In an attempt to find out what needs to be done to improve current supply chain methods and tools, the current research project 1) reviewed the literature to establish current approaches to Supply Chain Management (SCM); 2) identified what tools and methods are availab...

  6. Supply chain management: An opportunity for metaheuristics

    OpenAIRE

    Ramalhinho-Louren??o, Helena

    2001-01-01

    In today?s highly competitive and global marketplace the pressure on organizations to find new ways to create and deliver value to customers grows ever stronger. In the last two decades, logistics and supply chain has moved to the center stage. There has been a growing recognition that it is through an effective management of the logistics function and the supply chain that the goal of cost reduction and service enhancement can be achieved. The key to success in Supply Chain...

  7. Knowledge sharing in organic food supply chains

    OpenAIRE

    Kottila, Marja-Riitta

    2009-01-01

    Although local, short supply chains are regarded as most suitable for organic products, most organic food is sold through general retailers. The extended supply chains create challenges: (1) how to sustain the connection between farmers and consumers and deliver the multifaceted value of organic food and (2) how to cooperate to meet both the needs of consumers and of each independent company involved in the supply chain. This publication gives among other things practical implications concern...

  8. Logistics and Supply Chain Practices in India

    OpenAIRE

    Samir K. Srivastava

    2006-01-01

    This paper seeks to comprehensively examine and present the state of logistics and supply chain practices in India. We consider the two separately as they have still not integrated seamlessly in the Indian context. Our study is based on both field observations and secondary data. We focus on supply chain collaboration and partnerships, supply chain structure, facilities network design, transportation and logistics and the role of Information and Communications Technologies (ICT). On-site obse...

  9. Single chain elasticity and thermoelasticity of polyethylene

    OpenAIRE

    Titantah, John T.; Pierleoni, Carlo; Ryckaert, Jean-Paul

    2002-01-01

    Single-chain elasticity of polyethylene at $\\theta$ point up to 90% of stretching with respect to its contour length is computed by Monte-Carlo simulation of an atomistic model in continuous space. The elasticity law together with the free-energy and the internal energy variations with stretching are found to be very well represented by the wormlike chain model up to 65% of the chain elongation, provided the persistence length is treated as a temperature dependent parameter. Beyond this value...

  10. Sustaining Supply Chain Operations through Lean Manufacturing

    OpenAIRE

    Suphattra Ketsarapong; Kong Suwantaranrangsri; Kongkiti Phusavat; Binshan Lin

    2012-01-01

    Purpose – The study aims to report a case study in a Thai Electronics Manufacturing deploying a lean manufacturing approach, and to discuss the value gained in their supply chain operations. These experiences can be adapted by others for design, redesign, and problem shooting when analyzing the performance of supply chain operations. Approach – The paper is based on actual activities in a case study. This paper begins by reviewing the relevant literature on supply chain operations and supply ...

  11. Waste Reduction in Fresh Food Supply Chains

    DEFF Research Database (Denmark)

    Kaipia, Riikka; Loikkanen, Lauri; Dukovska-Popovska, Iskra

    2011-01-01

    The paper studies a well-known phenomenon, information sharing in supply chains, in a new context, fresh foods, with a specific goal, supporting sustainable performance in the supply chain. Fresh foods are important for retail stores, representing around half of retail sales, but form a challenging...... and heterogeneous group of products to manage. The value of the paper lies in its pointing out detailed solutions to how in real-life supply chains data can be used efficiently to improve the performance of the supply chain....

  12. Responsive supply chain: modeling and simulation

    Directory of Open Access Journals (Sweden)

    Amit Kumar Sinha

    2015-06-01

    Full Text Available Unexpected occurrence like natural calamity, abruptly change in customer demands, upgradation of technologies, necessity of compatible suppliers etc. is the most challenging issues even for efficient global supply chain management. Therefore, modeling of responsive supply chain is an emerging technology for sustaining any firm/industry in future competitive environment. In this paper, an attempt has been made to not only analyze the performance of efficient supply chain management but also how to improve the performance of existing supply chain with the objective of developing a modeling of responsive supply chain management. The complexity of the model is also highlighted with the help of numerical example. This paper also explores the possibility to mathematical modeling of the responsive supply chain which will be an emerging topic for researchers and practitioners. The modeling of responsive supply chain can be employed as a competitive strategy for e-commerce, green supply chain, and compatible supplier selection problem. The another salient feature of this paper is that a distinct comparative literature review of the lean, agile, efficient, and responsive supply chain management has been presented.

  13. Stochastically Perturbed Chains of Variable Memory

    OpenAIRE

    Garcia, Nancy L.; Moreira, Lucas

    2013-01-01

    In this paper, we study inference for chains of variable order under two distinct contamination regimes. Consider we have a chain of variable memory on a finite alphabet containing zero. At each instant of time an independent coin is flipped and if it turns head a contamination occurs. In the first regime a zero is read independent of the value of the chain. In the second regime, the value of another chain of variable memory is observed instead of the original one. Our results state that the ...

  14. Toc Approach for Supply Chain Performance Enhancement

    Directory of Open Access Journals (Sweden)

    Brijesh Ainapur

    2011-12-01

    Full Text Available Many foundries are operating at lower levels than the installed capacities. Study of 56 foundries acrossIndia has shown that only 68% of installed capacities are being utilized. This is mainly because of lack ofco-ordination among the supply chain partners. This study is an effort in identifying these gaps using TOCapproach which will help in supply chain performance enhancement.Field of Supply Chain Management witnessed rapid growth in recent past and proved to be a successfultool for organizations growth. Success of supply chain improvement initiative lies in selection ofappropriate Key Performance Indicators (KPIs using best suitable supply chain framework. Theseperformance indicators are to be measured, monitored and controlled with proper review mechanism.This study presents a methodology for identification of the KPI’s from the supply chain metrics suitablefor foundries. Selection of the KPI’s is done using Supply Chain Operations Reference (SCORframework. Analytical Hierarchy Process (AHP is used for decomposing the goal into micro level foranalyzing and prioritizing KPIs. In order to study the gap between as-is-state and as-to-be state,benchmarking is carried by comparing foundry industry KPIs with global best practice industry average.To optimize the supply chain performance, Goal Programming function is formulated using AHP ratingsand solved using WINQSB software. Theory of Constraint (TOC management philosophy is applied forfinding the constraints, on improving these constraints supply chain performance enhancement isachieved.

  15. Edge states in Open Antiferromagnetic Heisenberg Chains

    OpenAIRE

    Qin, Shaojin; Ng, Tai-Kai; Su, Zhao-Bin

    1995-01-01

    In this letter we report our results in investigating edge effects of open antiferromagnetic Heisenberg spin chains with spin magnitudes $S=1/2, 1,3/2,2$ using the density-matrix renormalization group (DMRG) method initiated by White. For integer spin chains, we find that edge states with spin magnitude $S_{edge}=S/2$ exist, in agreement with Valence-Bond-Solid model picture. For half-integer spin chains, we find that no edge states exist for $S=1/2$ spin chain, but edge state exists in $S=3/...

  16. An Evaluation of a Markov Chain Monte Carlo Method for the Rasch Model.

    Science.gov (United States)

    Kim, Seock-Ho

    2001-01-01

    Examined the accuracy of the Gibbs sampling Markov chain Monte Carlo procedure for estimating item and person (theta) parameters in the one-parameter logistic model. Analyzed four empirical datasets using the Gibbs sampling, conditional maximum likelihood, marginal maximum likelihood, and joint maximum likelihood methods. Discusses the conditions…

  17. Systematic sampling with errors in sample locations

    DEFF Research Database (Denmark)

    Ziegel, Johanna; Baddeley, Adrian; Dorph-Petersen, Karl-Anton; Jensen, Eva Bjørn Vedel

    2010-01-01

    variance analysis using point process methods. We then analyze three different models for the error process, calculate exact expressions for the variances, and derive asymptotic variances. Errors in the placement of sample points can lead to substantial inflation of the variance, dampening of......Systematic sampling of points in continuous space is widely used in microscopy and spatial surveys. Classical theory provides asymptotic expressions for the variance of estimators based on systematic sampling as the grid spacing decreases. However, the classical theory assumes that the sample grid...... is exactly periodic; real physical sampling procedures may introduce errors in the placement of the sample points. This paper studies the effect of errors in sample positioning on the variance of estimators in the case of one-dimensional systematic sampling. First we sketch a general approach to...

  18. 9 CFR 147.30 - Laboratory procedure recommended for the polymerase chain reaction (PCR) test for Mycoplasma...

    Science.gov (United States)

    2010-01-01

    ... the polymerase chain reaction (PCR) test for Mycoplasma gallisepticum and M. synoviae. 147.30 Section... Examination Procedures § 147.30 Laboratory procedure recommended for the polymerase chain reaction (PCR) test... sample (100 to 2000 ng/5 μl) with one of the following 45 μl PCR cocktails: (i) 5 μl 10x PCR buffer, 1...

  19. The Retail Value Chain: Linking Employee Perceptions to Employee Performance, Customer Evaluations, and Store Performance

    OpenAIRE

    James G. Maxham, III; Richard G. Netemeyer; Lichtenstein, Donald R

    2008-01-01

    The authors test a value chain model entailing a progression of influence from retail employee job perceptions -> retail employee job performances -> customer evaluations -> customer spending and comparable store sales growth. The authors test the model using three matched samples of 1,615 retail employees, 57,656 customers, and 306 stores of a single retail chain. The authors find that three retail employee job perceptions (conscientiousness, perceived organizational justice, and organizatio...

  20. Branched-Chain Amino Acids

    Directory of Open Access Journals (Sweden)

    Matteo Ghiringhelli

    2015-07-01

    Full Text Available Our study is focused on evaluation and use of the most effective and correct nutrients. In particular, our attention is directed to the role of certain amino acids in cachectic patients.During parenteral nutrition in humans, physician already associates in the PN-bags different formulations including amino acids, lipids and glucose solutions or essential amino acids solution alone or exclusively branched-chain amino acids (BCAA. Studies investigated the effects of dietary BCAA ingestion on different diseases and conditions such as obesity and metabolic disorders, liver disease, muscle atrophy, cancer, impaired immunity or injuries (surgery, trauma, burns, and sepsis. BCAAs have been shown to affect gene expression, protein metabolism, apoptosis and regeneration of hepatocytes, and insulin resistance. They have also been shown to inhibit the proliferation of liver cancer cells in vitro, and are essential for lymphocyte proliferation and dendritic cell maturation. Oral or parenteral administration of these three amino acids will allow us to evaluate the real efficacy of these compounds during a therapy to treat malnutrition in subjects unable to feed themselves.

  1. Geometry behind chordal Loewner chains

    CERN Document Server

    Contreras, Manuel D; Gumenyuk, Pavel

    2010-01-01

    Loewner Theory is a deep technique in Complex Analysis affording a basis for many further important developments such as the proof of famous Bieberbach's conjecture and well-celebrated Schramm's Stochastic Loewner Evolution (SLE). It provides analytic description of expanding domains dynamics in the plane. Two cases have been developed in the classical theory, namely the {\\it radial} and the {\\it chordal} Loewner evolutions, referring to the associated families of holomorphic self-mappings being normalized at an internal or boundary point of the reference domain, respectively. Recently there has been introduced a new approach [arXiv:0807.1594v1, arXiv:0807.1715v1, arXiv:0902.3116v1] bringing together, and containing as quite special cases, radial and chordal variants of Loewner Theory. In the framework of this approach we address the question what kind of systems of simply connected domains can be described by means of Loewner chains of chordal type. As an answer to this question we establish a necessary and ...

  2. Migration of radionuclides in chosen parts of food chains

    International Nuclear Information System (INIS)

    Results of environmental contamination measurements are reported. The aim of this study was to compare the amount of radiocaesium in chosen parts of food chains from localities in the eastern Slovakia. Prevailing part of radiocaesium is in the upper layer of soils and specific activity of 137Cs in the first layer for locality Stara Voda in 2000 achieved 152.4 Bq · kg-1. The amount of artificial radionuclides in the individual compartments of food chains is at present at a very low level. Mushrooms are characterised by high ability to accumulate radiocaesium. From studied species of mushrooms the highest value was determined in sample of Sarcodon imbricatum and specific activity achieved 6.24 kBq · kg-1 d. w. (author)

  3. Consumer-perceived quality in 'traditional' food chains

    DEFF Research Database (Denmark)

    Krystallis, Athanasios; Chryssochoidis, George; Scholderer, Joachim

    2007-01-01

    develop the profile of different consumer segments in relation to these perceptions. The substantial findings of the survey include the fact that, despite their enormous per capita consumption, the majority of consumers are not particularly involved in the meat-purchasing process. Rather they attach......Recent food scares have increased consumer concern about meat safety. However, the Greek 'traditional' meat supply chain from producers to local butchers does not seem to realise the pressing consumer demand for certified meat quality. Or is it that, in such food chains, this demand is not so...... pressing yet? The present paper seeks to answer this question based on a survey conducted in the Athens area, involving a sample of 268 participants responsible for food purchasing decisions. The survey mainly aims to develop an integrated model of factors that affect consumer-perceived meat quality and to...

  4. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, Simon Minze; Vertregt, Maarten

    2010-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital converte

  5. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, Simon Minze; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital converte

  6. Optimizing Supply Chain Performance in China with Country-Specific Supply Chain Coordination

    OpenAIRE

    Herczeg, András; Vastag, Gyula

    2012-01-01

    The implementation of country-specific supply chain coordination techniques ensures an optimal global supply chain performance. This paper looks at success factors going with a supply chain coordination strategy within the global supply chain of a successful, medium-sized, privately-owned company, one having locations in North America (USA), Europe (Hungary) and Asia (China). Through the shown GSL’s Chinese plant, we will endeavor to argue that increased collaboration in the supply network wi...

  7. A new framework for supply chain risk management through supply chain management capability

    OpenAIRE

    Göçer, Aysu; Yumurtacı, Işık Özge; Yurt, Öznur; Baltacıoğlu, Tunçdan

    2015-01-01

    Supply chain risk management is considered as one of the most powerful competitive tools for the companies. Therefore, the concept has caught the attention of researchers especially in the recent years. However, supply chain risk management has not been examined in the literature by considering the maturity and capability levels of supply chain members. This study aims to address this gap and develops a new framework on supply chain risk management which focuses on different...

  8. The fishing industry - toward supply chain modelling

    DEFF Research Database (Denmark)

    Jensen, Toke Koldborg; Nielsen, Jette; Larsen, Erling P.;

    Mathematical models for simulating and optimizing supply chain aspects such as distribution planning and optimal use of raw materials are widely used. However, modelling based on a holistic chain view is less studied, and food-related aspects such as quality and shelf life issues enforce additional...

  9. Towards effective food chains : models and applications

    NARCIS (Netherlands)

    Trienekens, J.H.; Top, J.L.; Vorst, van der J.G.A.J.; Beulens, A.J.M.

    2010-01-01

    Food chain management research can help in the analysis and redesign of value creation and the product flow throughout the chain from primary producer down to the consumer. The aim is to meet consumer and societal requirements effectively at minimal cost. In the Wageningen UR strategic research prog

  10. Bethe vectors for XXX-spin chain

    International Nuclear Information System (INIS)

    The paper deals with algebraic Bethe ansatz for XXX-spin chain. Generators of Yang-Baxter algebra are expressed in basis of free fermions and used to calculate explicit form of Bethe vectors. Their relation to N-component models is used to prove conjecture about their form in general. Some remarks on inhomogeneous XXX-spin chain are included

  11. Quantum channels in random spin chains

    International Nuclear Information System (INIS)

    We study the entanglement between pairs of qubits in a random antiferromagnetic spin-1/2 chain at zero temperature. We show that some very distant pairs of qubits are highly entangled, being almost pure Bell states. Furthermore, the probability to obtain such spin pairs is proportional to the chain disorder strength and inversely proportional to the square of their separation

  12. Stakeholder salience in humanitarian supply chain management

    OpenAIRE

    Schiffling, Sarah

    2013-01-01

    Mitchell et al.(1997) developed a framework for assessing the salience of stakeholder groups based on their power, urgency and the legitimacy of their claim. This has been applied to illustrate the complexities of stakeholder interactions in humanitarian supply chains and to provide insights for their management and further research. Keywords: Supply chain management, Humanitarian logistics, Stakeholder salience

  13. Value Chain Responsibility in Emerging Technologies

    NARCIS (Netherlands)

    Bos, Colette; van Lente, Harro

    2014-01-01

    Corporate social responsibility (CSR) and value chain responsibility (VCR) have gained increasing importance for firms. The literature on these topics reports on CSR practices for established firms with existing technologies and stable value chains. This raises questions about the viability of CSR a

  14. Using Games to Teach Markov Chains

    Science.gov (United States)

    Johnson, Roger W.

    2003-01-01

    Games are promoted as examples for classroom discussion of stationary Markov chains. In a game context Markov chain terminology and results are made concrete, interesting, and entertaining. Game length for several-player games such as "Hi Ho! Cherry-O" and "Chutes and Ladders" is investigated and new, simple formulas are given. Slight…

  15. Qualitative methodology for efficient food chain design

    NARCIS (Netherlands)

    Apaiah, R.K.; Hendrix, E.M.T.; Meerdink, G.; Linnemann, A.R.

    2005-01-01

    This paper presents a methodology to efficiently design food supply chains. The goals of quality, cost and environmental load are looked at independently of each other. Food chains are made up of links and are designed to deliver a particular product with consumer-specified attributes. These attribu

  16. Information Technologies and Supply Chain Integration

    DEFF Research Database (Denmark)

    Lemoine, W; Mortensen, Ole

    The goal of the Supply Chain Management process is to create value for customers, stakeholders and all supply chain members, through the integration of different processes like manufacturing flow management, customer service and order fulfillment. However, many firms fail in the path of achieving...

  17. Theory of chain association versus liquid condensation

    NARCIS (Netherlands)

    Roij, R. van

    1996-01-01

    We combine the original van der Waals description for liquid condensation with the association theory of ideal particles into a simple association theory of nonideal chains. The theory shows that vapor-liquid coexistence becomes metastable if the tendency to form weakly interacting chains is suffici

  18. The chain-length dependence test.

    Science.gov (United States)

    Stone, Matthew T; Heemstra, Jennifer M; Moore, Jeffrey S

    2006-01-01

    Trends obtained from systematic studies based on chain-length variation have provided valuable insight and understanding into the behavior of m-phenylene ethynylene foldamers. The generalization of this experimental approach, the chain-length dependence test, is useful for studying solution conformation, packing in the solid state, specific intrachain interactions, and the contributions of end groups to a particular property. PMID:16411735

  19. Localized Lymph Node Light Chain Amyloidosis

    Directory of Open Access Journals (Sweden)

    Binod Dhakal

    2015-01-01

    Full Text Available Immunoglobulin-derived light chain amyloidosis can occasionally be associated with localized disease. We present a patient with localized lymph node light chain amyloidosis without an underlying monoclonal protein or lymphoproliferative disorder and review the literature of lymph node amyloidosis discussing work-up and risk factors for systemic progression.

  20. Bethe vectors for XXX-spin chain

    Science.gov (United States)

    Burdík, Čestmír; Fuksa, Jan; Isaev, Alexei

    2014-11-01

    The paper deals with algebraic Bethe ansatz for XXX-spin chain. Generators of Yang-Baxter algebra are expressed in basis of free fermions and used to calculate explicit form of Bethe vectors. Their relation to N-component models is used to prove conjecture about their form in general. Some remarks on inhomogeneous XXX-spin chain are included.

  1. Operational excellence in logistics and supply chains

    OpenAIRE

    2015-01-01

    This volume contains research contributions by an international group of authors focusing on innovative models to optimize logistics and supply chains at an operational level. They address process efficiency and data-related aspects. Supply chain security insights are also given.

  2. Supply chain coordination in industrial symbiosis

    DEFF Research Database (Denmark)

    Herczeg, Gabor; Akkerman, Renzo; Hauschild, Michael Zwicky

    2013-01-01

    Industrial symbiosis (IS) is a form of supply chain cooperation in industrial networks in order to achieve collective benefits by leveraging each other’s by-products and sharing services and utilities. This paper investigates the concept of IS from the perspective of supply chain coordination (SCC...

  3. Synchronize Your Supply Chain with RFID

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    1 Executive Summary Driving efficiencies throughout your supply chain and increasing the velocity of items through the supply chain from creation to consumer is more than a business mandate today; it’s a matter of business survival. If your company doesn’t do it, your competition will. Radio Frequency Identification (RFID) is a true next-generation

  4. Small-Sample Equating Using a Synthetic Linking Function

    Science.gov (United States)

    Kim, Sooyeon; von Davier, Alina A.; Haberman, Shelby

    2008-01-01

    This study addressed the sampling error and linking bias that occur with small samples in a nonequivalent groups anchor test design. We proposed a linking method called the synthetic function, which is a weighted average of the identity function and a traditional equating function (in this case, the chained linear equating function). Specifically,…

  5. Teaching Lean Six Sigma within a Supply Chain Context: The Airplane Supply Chain Simulation

    Science.gov (United States)

    Ellis, Scott C.; Goldsby, Thomas J.; Bailey, Ana M.; Oh, Jae-Young

    2014-01-01

    Lean six sigma is a management methodology that firms can employ to achieve substantial improvement in supply chain performance. However, few pedagogical exercises facilitate students' use of a comprehensive set of lean six sigma principles within a supply chain context. We describe the Airplane Supply Chain Simulation that helps students…

  6. Effective food supply chains; generating, modelling and evaluating supply chain scenarios

    NARCIS (Netherlands)

    Vorst, van der J.G.A.J.

    2000-01-01

    Logistical co-ordination in FMCG supply chains

    The overall objectives of the research described in this thesis were to obtain insight into the applicability of the concept Supply Chain Management (SCM) in food supply chains (SCs) from a logistical point of view, and to find an efficient and

  7. A conceptual framework for supply chain governance: An application to agri-food chains in China

    NARCIS (Netherlands)

    Zhang, X.Y.; Aramyan, L.H.

    2009-01-01

    Purpose - Chinese agri-food chains consist of the millions of small scale farmers, who are not well structured and organized in the supply chain. Owing to market liberalization and globalization, one of the most challenging issues along agri-food chains in China is becoming the issue of how to link

  8. Chain graph models and their causal interpretations

    DEFF Research Database (Denmark)

    Lauritzen, Steffen Lilholt; Richardson, Thomas S.

    2002-01-01

    equilibrium distributions of dynamic models with feed-back. These dynamic interpretations lead to a simple theory of intervention, extending the theory developed for directed acyclic graphs. Finally, we contrast chain graph models under this interpretation with simultaneous equation models which have......Chain graphs are a natural generalization of directed acyclic graphs and undirected graphs. However, the apparent simplicity of chain graphs belies the subtlety of the conditional independence hypotheses that they represent. There are many simple and apparently plausible, but ultimately fallacious......, interpretations of chain graphs that are often invoked, implicitly or explicitly. These interpretations also lead to flawed methods for applying background knowledge to model selection. We present a valid interpretation by showing how the distribution corresponding to a chain graph may be generated from the...

  9. REPRESENTING MARKOV CHAINS WITH TRANSITION DIAGRAMS

    Directory of Open Access Journals (Sweden)

    Farida Kachapova

    2013-01-01

    Full Text Available Stochastic processes have many useful applications and are taught in several university programmes. Students often encounter difficulties in learning stochastic processes and Markov chains, in particular. In this article we describe a teaching strategy that uses transition diagrams to represent a Markov chain and to re-define properties of its states in simple terms of directed graphs. This strategy utilises the students’ intuition and makes the learning of complex concepts about Markov chains faster and easier. The method is illustrated by worked examples. The described strategy helps students to master properties of finite Markov chains, so they have a solid basis for the study of infinite Markov chains and other stochastic processes.

  10. Integrating product design into the supply chain

    DEFF Research Database (Denmark)

    Khan, Omera; Stolte, Terje; Creazza, Alessandro;

    2016-01-01

    Purpose: The aim of the research is to illustrate how companies can create competitive capabilities through integration of product design into the supply chain. In doing so the paper reveals the challenges and the opportunities that companies face when integrating product design and supply chain...... opportunities and challenges when integrating product design and the supply chain and subsequently a step-by-step guide is developed to address these. Practical Implications: The research provides key recommendations to companies on how to create competitive capabilities by integrating product design into the...... supply chain. Originality/Value: This paper provides novel insights to both practitioners and researchers. For practitioners detailed recommendations are given on how they can maximise benefits through integrating product design into the supply chain. The RBV has been harnessed to highlight how...

  11. Designing value-creating supply chain networks

    CERN Document Server

    Martel, Alain

    2016-01-01

    Focusing on the design of robust value-creating supply chain networks (SCN) and key strategic issues related to the number; location, capacity and mission of supply chain facilities (plants, distribution centers) – as well as the network structure required to provide flexibility and resilience in an uncertain world – this book presents an innovative methodology for SCN reengineering that can be used to significantly improve the bottom line of supply chain dependent businesses. Providing readers with the tools needed to analyze and model value creation activities, Designing Value-Creating Supply Chain Networks examines the risks faced by modern supply chains, and shows how to develop plausible future scenarios to evaluate potential SCN designs. The design methods proposed are based on a visual representation formalism that facilitates the analysis and modeling of SCN design problems, book chapters incorporate several example problems and exercises which can be solved with Excel tools (Analysis tools and So...

  12. Research Methodologies in Supply Chain Management

    DEFF Research Database (Denmark)

    Kotzab, Herbert

    While supply chain management has risen to great prominence in recent year, there are hardly related developments in research methodologies. Yet, as supply chains cover more than one company, one central issue is how to collect and analyse data along the whole or relevant part of the supply chain....... Within the 36 chapters 70 authors bring together a rich selection of theoretical and practical examples of how research methodologies are applied in supply chain management. The book contains papers on theoretical implications as well as papers on a range of key methods, such as modelling, surveys, case...... studies or action research. It will be of great interest to researchers in the area of supply chain management and logistics, but also to neighbouring fields, such as network management or global operations....

  13. Supply Chain Management in Industrial Symbiosis Networks

    DEFF Research Database (Denmark)

    Herczeg, Gabor

    2016-01-01

    Sustainable supply chain management deals with the design and operation of profitable supply chains that also respect limitations on natural resources, do no harm to the environment, and consider the social systems they operate in. In academic research on sustainable supply chain management, as...... sustainable develop- ment efforts, and emphasize synergistic relations, community, and collabora- tion. This thesis takes an operations and supply chain management perspec- tive on industrial symbiosis networks. More specifically, the thesis elaborates on the collaborative and competitive characteristics of......-product allocation strategies, which turn out to have different requirements and consequences for the organization and facilitation of the collaborative efforts. Overall, this thesis aims to ground industrial symbiosis in operations and supply chain management theory. The thesis thereby provides a basis for the...

  14. Sales Rebate Contracts in Fashion Supply Chains

    Directory of Open Access Journals (Sweden)

    Chun-Hung Chiu

    2012-01-01

    Full Text Available We explore in this paper the performance of sales rebate contracts in fashion supply chains. We conduct both analytical and numerical analyses via a mean-variance framework with reference to real empirical data. To be specific, we evaluate the expected profits and variance of profits (risk of the fashion supply chains, fashion retailers, and manufacturers under (1 the currently implemented sales rebate practices, (2 the case without sales rebate, and (3 the theoretical coordination situation (if target sales rebate is adopted. In addition, we analyze how sales effort affects the performances of the supply chain and its agents. Our analysis indicates that the rebate contracts may hurt the retailer and the manufacturer of a fashion supply chain when it is inappropriately set. Moreover, a properly designed sales rebate contract not only can coordinate the supply chain (with retail sales effort but can also improve expected profits and lower the levels of risk for both the manufacturer and the retailer.

  15. Direct current hopping conductance along DNA chain

    Institute of Scientific and Technical Information of China (English)

    Ma Song-Shan; Xu Hui; Liu Xiao-Liang; Li Ming-Jun

    2007-01-01

    This paper proposes a model of direct current(DC) electron hopping transport in DNA,in which DNA is considered as a binary one-dimensional disordered system.To quantitatively study the DC conductivity in DNA,it numerically calculates the DC conductivity of DNA chains with difierent parameter values.The result shows that the DC conductivity of DNA chain increases with the increase of temperature.And the conductivity of DNA chain is depended on the probability P.which represents the degree of compositional disorder in a DNA sequence to some extent.For P<0.5,the conductivity of DNA chain decreases with the increase of P,while for P≥0.5,the conductivity increases with the increase of p.The DC conductivity in DNA chain also varies with the change of the electric field,it presents non-Ohm's law conductivity characteristics.

  16. Structural repertoire of immunoglobulin λ light chains

    KAUST Repository

    Chailyan, Anna

    2011-03-01

    The immunoglobulin λ isotype is present in nearly all vertebrates and plays an important role in the human immune system. Despite its importance, few systematic studies have been performed to analyze the structural conformation of its variable regions, contrary to what is the case for κ and heavy chains. We show here that an analysis of the structures of λ chains allows the definition of a discrete set of recurring conformations (canonical structures) of their hypervariable loops and, most importantly, the identification of sequence constraints that can be used to predict their structure. We also show that the structural repertoire of λ chains is different and more varied than that of the κ chains, consistently with the current view of the involvement of the two major light-chain families in complementary strategies of the immune system to ensure a fine tuning between diversity and stability in antigen recognition. © 2011 Wiley-Liss, Inc.

  17. Environmental management the supply chain perspective

    CERN Document Server

    Wong, Christina W Y; Lun, Y H Venus; Cheng, T C E

    2015-01-01

    In view of the increasing quest for environmental management in businesses, this book provides a good reference to firms to understand how they may manage their supply chains to improve business and environmental performance. The book consists of six chapters covering such topics as environmental management, environmental management practices with supply chain efforts, collaborative environmental management, organizational capabilities in environmental management, environmental disclosure, and closed-loop supply chains. The book presents theory-driven discussions on the link between environmental management and business performance in the context of supply chain management. The book will be useful for firms to learn from the research findings and real-life cases to develop plans to implement environmental management practices jointly with supply chain partners.

  18. Ratchet behaviour of polarons in molecular chains

    Energy Technology Data Exchange (ETDEWEB)

    Brizhik, L S; Eremko, A A [Bogolyubov Institute for Theoretical Physics, 03680 Kyiv (Ukraine); Piette, B M A G; Zakrzewski, W J [Department of Mathematical Sciences, University of Durham, Durham DH1 3LE (United Kingdom)], E-mail: brizhik@bitp.kiev.ua, E-mail: eremko@bitp.kiev.ua, E-mail: B.M.A.G.Piette@durham.ac.uk, E-mail: W.J.Zakrzewski@durham.ac.uk

    2008-06-25

    We study the ratchet behaviour of polarons in diatomic molecular chains under the influence of an external electromagnetic field which is periodic in time. We show that in asymmetric chains a harmonic unbiased field causes a drift of polarons. This phenomenon has a threshold with respect to the intensity and the frequency of the field. In spatially symmetric chains a harmonic periodic electric field generates oscillations of polarons but does not result in their movement. The polaron drift current can be induced in symmetric chains by a time periodic asymmetric external field. This complex dynamics of polarons is generated by the interplay between the Peierls-Nabarro barrier and dissipative effects in the chains.

  19. Ratchet behaviour of polarons in molecular chains

    International Nuclear Information System (INIS)

    We study the ratchet behaviour of polarons in diatomic molecular chains under the influence of an external electromagnetic field which is periodic in time. We show that in asymmetric chains a harmonic unbiased field causes a drift of polarons. This phenomenon has a threshold with respect to the intensity and the frequency of the field. In spatially symmetric chains a harmonic periodic electric field generates oscillations of polarons but does not result in their movement. The polaron drift current can be induced in symmetric chains by a time periodic asymmetric external field. This complex dynamics of polarons is generated by the interplay between the Peierls-Nabarro barrier and dissipative effects in the chains

  20. A Mars Sample Return Sample Handling System

    Science.gov (United States)

    Wilson, David; Stroker, Carol

    2013-01-01

    We present a sample handling system, a subsystem of the proposed Dragon landed Mars Sample Return (MSR) mission [1], that can return to Earth orbit a significant mass of frozen Mars samples potentially consisting of: rock cores, subsurface drilled rock and ice cuttings, pebble sized rocks, and soil scoops. The sample collection, storage, retrieval and packaging assumptions and concepts in this study are applicable for the NASA's MPPG MSR mission architecture options [2]. Our study assumes a predecessor rover mission collects samples for return to Earth to address questions on: past life, climate change, water history, age dating, understanding Mars interior evolution [3], and, human safety and in-situ resource utilization. Hence the rover will have "integrated priorities for rock sampling" [3] that cover collection of subaqueous or hydrothermal sediments, low-temperature fluidaltered rocks, unaltered igneous rocks, regolith and atmosphere samples. Samples could include: drilled rock cores, alluvial and fluvial deposits, subsurface ice and soils, clays, sulfates, salts including perchlorates, aeolian deposits, and concretions. Thus samples will have a broad range of bulk densities, and require for Earth based analysis where practical: in-situ characterization, management of degradation such as perchlorate deliquescence and volatile release, and contamination management. We propose to adopt a sample container with a set of cups each with a sample from a specific location. We considered two sample cups sizes: (1) a small cup sized for samples matching those submitted to in-situ characterization instruments, and, (2) a larger cup for 100 mm rock cores [4] and pebble sized rocks, thus providing diverse samples and optimizing the MSR sample mass payload fraction for a given payload volume. We minimize sample degradation by keeping them frozen in the MSR payload sample canister using Peltier chip cooling. The cups are sealed by interference fitted heat activated memory

  1. Auto component supply chain: a path to global India

    OpenAIRE

    Kale, Shailendra; Palacios Fernández, Miguel; Tafur Segura, José Javier; Jarad, Rajendra; Chitale, C.M.

    2011-01-01

    Supply chain management works to bring the supplier, the distributor, and the customer into one cohesive process. The Supply Chain Council defined supply chain as ‘Supply Chain: The flow and transformation of raw materials into products from suppliers through production and distribution facilities to the ultimate consumer., and then Sunil Chopra and Meindl, (2001) have define Supply chain management as ‘Supply Chain Management involves the flows between and among stages in a supply chain to m...

  2. A sampling algorithm for segregation analysis

    Directory of Open Access Journals (Sweden)

    Henshall John

    2001-11-01

    Full Text Available Abstract Methods for detecting Quantitative Trait Loci (QTL without markers have generally used iterative peeling algorithms for determining genotype probabilities. These algorithms have considerable shortcomings in complex pedigrees. A Monte Carlo Markov chain (MCMC method which samples the pedigree of the whole population jointly is described. Simultaneous sampling of the pedigree was achieved by sampling descent graphs using the Metropolis-Hastings algorithm. A descent graph describes the inheritance state of each allele and provides pedigrees guaranteed to be consistent with Mendelian sampling. Sampling descent graphs overcomes most, if not all, of the limitations incurred by iterative peeling algorithms. The algorithm was able to find the QTL in most of the simulated populations. However, when the QTL was not modeled or found then its effect was ascribed to the polygenic component. No QTL were detected when they were not simulated.

  3. Chain packing in polycarbonate glasses

    Science.gov (United States)

    Stueber, Dirk; Yu, Tsyr-Yan; Hess, Berk; Kremer, Kurt; O'Connor, Robert D.; Schaefer, Jacob

    2010-03-01

    Chain packing in homogeneous blends of carbonate C13-labeled bisphenol A polycarbonate with either (i) CF3-labeled bisphenol A polycarbonate or (ii) ring-F-labeled bisphenol A polycarbonate has been characterized using C13{F19} rotational-echo double-resonance (REDOR) nuclear magnetic resonance. In both blends, the C13 observed spin was at high concentration, and the F19 dephasing or probe spin was at low concentration. In this situation, an analysis in terms of a distribution of isolated heteronuclear pairs of spins is valid. Nearest-neighbor separation of C13 and F19 labels was determined by accurately mapping the initial dipolar evolution using a shifted-pulse version of REDOR. Based on the results of this experiment, the average distance from a ring-fluorine to the nearest C13O is more than 1.2 Å greater than the corresponding CF3C13O distance. Next-nearest and more-distant-neighbor separations of labels were measured in a 416-rotor-cycle constant-time version of REDOR for both blends. Statistically significant local order was established for the nearest-neighbor labels in the methyl-labeled blend. These interchain packing results are in qualitative agreement with predictions based on coarse-grained simulations of a specially adapted model for bisphenol A polycarbonate. The model itself has been previously used to determine static and dynamic properties of polycarbonate with results in good agreement with those from rheological and neutron scattering experiments.

  4. Optimal sampling efficiency in Monte Carlo sampling with an approximate potential

    Energy Technology Data Exchange (ETDEWEB)

    Coe, Joshua D [Los Alamos National Laboratory; Shaw, M Sam [Los Alamos National Laboratory; Sewell, Thomas D [U MISSOURI

    2009-01-01

    Building on the work of Iftimie et al., Boltzmann sampling of an approximate potential (the 'reference' system) is used to build a Markov chain in the isothermal-isobaric ensemble. At the endpoints of the chain, the energy is evaluated at a higher level of approximation (the 'full' system) and a composite move encompassing all of the intervening steps is accepted on the basis of a modified Metropolis criterion. For reference system chains of sufficient length, consecutive full energies are statistically decorrelated and thus far fewer are required to build ensemble averages with a given variance. Without modifying the original algorithm, however, the maximum reference chain length is too short to decorrelate full configurations without dramatically lowering the acceptance probability of the composite move. This difficulty stems from the fact that the reference and full potentials sample different statistical distributions. By manipulating the thermodynamic variables characterizing the reference system (pressure and temperature, in this case), we maximize the average acceptance probability of composite moves, lengthening significantly the random walk between consecutive full energy evaluations. In this manner, the number of full energy evaluations needed to precisely characterize equilibrium properties is dramatically reduced. The method is applied to a model fluid, but implications for sampling high-dimensional systems with ab initio or density functional theory (DFT) potentials are discussed.

  5. Fresh fish distribution chains: An analysis of three Danish and three Australian chains

    DEFF Research Database (Denmark)

    Frederiksen, Marco Thorup; Bremner, Allan

    2001-01-01

    . Traceability is a most important issue in the high value product chains in Australia. No information technology methods, were in evidence. In the Danish chains, nearly all traceability was lost after the collector/auction stage and the only evaluation of quality parameters was by inspection.......Information on traceability was gathered for three domestic Danish fish chains typical of the current trading practices in fresh seafood and for three chains exporting products from Australia to Japan. The same standard questionnaires, coupled with personal interviews, were used in all six chains...

  6. Rate-Distortion via Markov Chain Monte Carlo

    CERN Document Server

    Jalali, Shirin

    2008-01-01

    We propose an approach to lossy source coding, utilizing ideas from Gibbs sampling, simulated annealing, and Markov Chain Monte Carlo (MCMC). The idea is to sample a reconstruction sequence from a Boltzmann distribution associated with an energy function that incorporates the distortion between the source and reconstruction, the compressibility of the reconstruction, and the point sought on the rate-distortion curve. To sample from this distribution, we use a 'heat bath algorithm': Starting from an initial candidate reconstruction (say the original source sequence), at every iteration, an index i is chosen and the i-th sequence component is replaced by drawing from the conditional probability distribution for that component given all the rest. At the end of this process, the encoder conveys the reconstruction to the decoder using universal lossless compression. The complexity of each iteration is independent of the sequence length and only linearly dependent on a certain context parameter (which grows sub-log...

  7. Issue on supply chain of renewable energy

    International Nuclear Information System (INIS)

    Highlights: • One of the most relevant debates, is related to energy and environmental issue. • The development of renewable energy usage is due to several factors. • Indeed challenges from a supply chain point of view are required. • Thorough survey on topics of supply chain and renewable energy has been conducted. • Findings are discussed against the backdrop of SCs as sustainable RE option. - Abstract: Actually, one of the most relevant debates, among both citizens that government, is related to energy and environmental issue. The development of renewable energy usage is due to several factors such as the political strategic decisions and geographical situation. Indeed the high development of renewable energies requires challenges from a supply chain point of view. In this paper, a thorough survey of the extant literature on the topic of supply chain (SC) and renewable energy (RE) has been conducted. English papers published on international peer-reviewed journals from 2003 to 2013 have been considered. Sustainable Supply Chain Management (SSCM) resolves the duality between environmental, economic and social aspects. Sustainable manufacturing practices play an essential role in promoting renewable energy development and commercialization; this will require significant changes to the industry’s traditional Supply Chain Management and business model. The aim of the paper is investigate literature insights useful to increase the performance and overcome barriers to the RE supply chain development. Like many typical supply chains, also supply chain related to RE includes elements such as: physical, information, and financial flows. The present research is useful to individualize characteristics of a RE supply chain. Moreover, the research is useful improve the performance of RE supply chain in some aspects like: • better control supply chain costs to make renewable energy more affordable; • manage supply chain to address weakened demand in the near

  8. The composite supply chain efficiency model: A case study of the Sishen-Saldanha supply chain

    Directory of Open Access Journals (Sweden)

    Leila L. Goedhals-Gerber

    2016-01-01

    Full Text Available As South Africa strives to be a major force in global markets, it is essential that South African supply chains achieve and maintain a competitive advantage. One approach to achieving this is to ensure that South African supply chains maximise their levels of efficiency. Consequently, the efficiency levels of South Africa’s supply chains must be evaluated. The objective of this article is to propose a model that can assist South African industries in becoming internationally competitive by providing them with a tool for evaluating their levels of efficiency both as individual firms and as a component in an overall supply chain. The Composite Supply Chain Efficiency Model (CSCEM was developed to measure supply chain efficiency across supply chains using variables identified as problem areas experienced by South African supply chains. The CSCEM is tested in this article using the Sishen-Saldanda iron ore supply chain as a case study. The results indicate that all three links or nodes along the Sishen-Saldanha iron ore supply chain performed well. The average efficiency of the rail leg was 97.34%, while the average efficiency of the mine and the port were 97% and 95.44%, respectively. The results also show that the CSCEM can be used by South African firms to measure their levels of supply chain efficiency. This article concludes with the benefits of the CSCEM.

  9. Inference in Kingman's Coalescent with Particle Markov Chain Monte Carlo Method

    OpenAIRE

    Chen, Yifei; Xie, Xiaohui

    2013-01-01

    We propose a new algorithm to do posterior sampling of Kingman's coalescent, based upon the Particle Markov Chain Monte Carlo methodology. Specifically, the algorithm is an instantiation of the Particle Gibbs Sampling method, which alternately samples coalescent times conditioned on coalescent tree structures, and tree structures conditioned on coalescent times via the conditional Sequential Monte Carlo procedure. We implement our algorithm as a C++ package, and demonstrate its utility via a ...

  10. Prevalence and characteristics of Salmonella in the beef chain in the Republic of Ireland.

    Science.gov (United States)

    Khen, B K; Lynch, O A; Carroll, J; McDowell, D A; Duffy, G

    2014-12-01

    The study investigated the prevalence, concentration and characteristics of Salmonella spp. in the Irish beef chain. A total of 900 samples including bovine hides, carcasses and ground beef were examined for the pathogen over a 2-year study (July 2007-June 2009). Salmonella prevalence was low in all sample types; bovine hide (0.75%, 3 of 400); carcasses (0.25%, 1 of 400); and ground beef (3%, 3 of 100). All positive samples contained the pathogen in low concentrations (Dublin from hide and carcasses and S. Braenderup in ground beef. All isolates were susceptible to 13 anti-microbials. The study highlights that Salmonella can be found at low levels at all stages of beef chain production, processing and retail and that there is a need for multiple hurdle interventions and practices along the beef chain, which will reduce consumer exposure to this pathogen. PMID:24495534

  11. An in-vitro study to compare the force degradation of pigmented and non-pigmented elastomeric chains

    OpenAIRE

    Palathottungal Joseph Antony; Joby Paulose

    2014-01-01

    Aim: The purpose of the study was to compare the force delivery and force decay property of pigmented and non-pigmented elastomeric chains, widely used in orthodontic practice. Materials and Methods: Force delivered by the samples consisting of pigmented and non-pigmented elastomeric chains obtained from 3 manufacturers were tested at 3 time intervals (as received, after 24 hours and 21 days of stretching) to measure the force delivered by the test samples, as well as the force decay over...

  12. Study on Green Supply Chain Management Based on Circular Economy

    Science.gov (United States)

    Ying, Jiang; Li-jun, Zhou

    The article starts with circular economy and the connotation of green supply chain, then analyzes the difference between green supply chain and traditional supply chain and elaborates the content of green supply chain management. On that basis, the approach to implement green supply chain management in china shall be put forward.

  13. Spin chain sigma models with fermions

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Rafael [Institut de Physique, Universite de Neuchatel, Breguet 1, CH-2000 Neuchatel (Switzerland)]. E-mail: rafael.hernandez@cern.ch; Lopez, [Departamento de Fisica Teorica C-XI and Instituto de Fisica Teorica C-XVI, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2004-11-01

    The complete one-loop planar dilatation operator of N=4 supersymmetric Yang-Mills is isomorphic to the hamiltonian of an integrable PSU(2,2 vertical bar 4) quantum spin chain. We construct the non-linear sigma models describing the continuum limit of the SU(1|3) and SU(2|3) sectors of the complete N=4 chain. We explicitly identify the spin chain sigma model with the one for a superstring moving in AdS{sub 5} x S{sup 5} with large angular momentum along the five-sphere. (author)

  14. CONFORMATIONAL PROPERTIES OF STRETCHED POLYETHYLENE CHAIN

    Institute of Scientific and Technical Information of China (English)

    Lin-xi Zhang; De-lu Zhao

    2000-01-01

    When polyethylene chains are stretched, the chains are regarded as being confined in an infinite cylinder with decreasing diameter. The conformational properties of polyethylene chains confined in an infinite cylinder are investigated by using rotational isomeric state model. Using the average conformational energy and entropy and the average length, we can determine the elastic force f, or the fraction of the energy term to the total force fe/f, where fe=(б)/(б)/(б). Comparisons with experimental data are also made. The results of these microscopic calculations are discussed in terms of the macroscopic phenomena of rubber elasticity.

  15. Markov chains models, algorithms and applications

    CERN Document Server

    Ching, Wai-Ki; Ng, Michael K; Siu, Tak-Kuen

    2013-01-01

    This new edition of Markov Chains: Models, Algorithms and Applications has been completely reformatted as a text, complete with end-of-chapter exercises, a new focus on management science, new applications of the models, and new examples with applications in financial risk management and modeling of financial data.This book consists of eight chapters.  Chapter 1 gives a brief introduction to the classical theory on both discrete and continuous time Markov chains. The relationship between Markov chains of finite states and matrix theory will also be highlighted. Some classical iterative methods

  16. Supply Chain Management : importing football from Pakistan

    OpenAIRE

    Hafiz Muhammad, Bilal

    2016-01-01

    The concept of the thesis is to know how one can start a business of import and export in Finland and the steps taking place during this process. Pakistan is not in the top lists of doing import and export business but due to low labor cost,corporations prefer to do business with Pakistan. My thesis mainly consists on a business plan and supply chain management. As I have done my specialization in Supply chain management, it helped me to understand how the supply chain management and logis...

  17. Improving construction performance through supply chain management

    Institute of Scientific and Technical Information of China (English)

    王要武; 薛小龙

    2004-01-01

    A typical model of construction supply chain (CSC) is presented firstly. Then the characteristics and problems of CSC are identified. The authors also describe the progress towards adoption of supply chain management (SCM) in the construction industry. Traditional construction management approaches (CMAs) are compared with new SCM-based CMAs. The authors suggest that integrated SCM based on cooperating competition is crucial to improve construction performance. Based on relevant results from related research, a framework for integrated construction supply chain management (CSCM) is developed to guide the effective implementation of SCM in construction.

  18. Markov chains analytic and Monte Carlo computations

    CERN Document Server

    Graham, Carl

    2014-01-01

    Markov Chains: Analytic and Monte Carlo Computations introduces the main notions related to Markov chains and provides explanations on how to characterize, simulate, and recognize them. Starting with basic notions, this book leads progressively to advanced and recent topics in the field, allowing the reader to master the main aspects of the classical theory. This book also features: Numerous exercises with solutions as well as extended case studies.A detailed and rigorous presentation of Markov chains with discrete time and state space.An appendix presenting probabilistic notions that are nec

  19. Decay Chain Deduction of Uranium Fission Products.

    Science.gov (United States)

    Guo, Huiping; Tian, Chenyang; Wang, Xiaotian; Lv, Ning; Ma, Meng; Wei, Yingguang

    2016-07-01

    Delayed gamma spectrum is the fingerprint of uranium materials in arms control verification technology. The decay chain is simplified into basic state linear chain and excitation state linear chain to calculate and analyze the delayed gamma spectra of fission products. Formulas of the changing rule for nuclide number before and after zero-time are deduced. The C program for calculating the delayed gamma ray spectra data is constructed, and related experiments are conducted to verify this theory. Through analysis of the delayed gamma counts of several nuclides, the calculated results are found to be consistent with experimental values. PMID:27218290

  20. Ideal-Chain Collapse in Biopolymers

    CERN Document Server

    Neumann, R M

    2000-01-01

    A conceptual difficulty in the Hooke's-law description of ideal Gaussian polymer-chain elasticity is sometimes apparent in analyses of experimental data or in physical models designed to simulate the behavior of biopolymers. The problem, the tendency of a chain to collapse in the absence of external forces, is examined in the following examples: DNA-stretching experiments, gel electrophoresis, and protein folding. We demonstrate that the application of a statistical-mechanically derived repulsive force, acting between the chain ends, whose magnitude is proportional to the absolute temperature and inversely proportional to the scalar end separation removes this difficulty.