WorldWideScience

Sample records for bottlenecks

  1. Logistics bottlenecks

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-09-15

    Many of the vulnerabilities to Energy Access, Energy Security, and Environmental Sustainability result from impediments to reaching a global demand-supply balance, as well as local balances, for various energy sources and carriers. Vulnerabilities result from multiple reasons: regional imbalances of energy production and consumption, the bulky character of the majority of energy fuels, the virtual necessity of electricity consumption following its production, among others. To detect and prioritize respective 'bottlenecks' across energy carriers, they have to be measured. In this report, production, consumption, exports, and imports were measured across all major energy carriers for seven key regions of the world for three time frames-2008, 2020, and 2050. Imbalances between production and consumption form bottlenecks in each region.

  2. When is a bottleneck a bottleneck?

    CERN Document Server

    Schadschneider, Andreas; Popkov, Vladislav

    2015-01-01

    Bottlenecks, i.e. local reductions of capacity, are one of the most relevant scenarios of traffic systems. The asymmetric simple exclusion process (ASEP) with a defect is a minimal model for such a bottleneck scenario. One crucial question is "What is the critical strength of the defect that is required to create global effects, i.e. traffic jams localized at the defect position". Intuitively one would expect that already an arbitrarily small bottleneck strength leads to global effects in the system, e.g. a reduction of the maximal current. Therefore it came as a surprise when, based on computer simulations, it was claimed that the reaction of the system depends in non-continuous way on the defect strength and weak defects do not have a global influence on the system. Here we reconcile intuition and simulations by showing that indeed the critical defect strength is zero. We discuss the implications for the analysis of empirical and numerical data.

  3. Economic analysis of production bottlenecks

    Directory of Open Access Journals (Sweden)

    Lawrence Stephen R.

    1995-01-01

    Full Text Available The management of bottlenecks has become a central topic in the planning and control of production systems. In this paper, we critically analyze bottlenecks from an economic perspective. Using a queueing network model, we demonstrate that bottlenecks are inevitable when there are differences in job arrival rates, processing rates, or costs of productive resources. These differences naturally lead to the creation of bottlenecks both for facilities design and demand planning problems. To evaluate bottlenecks from an economic perspective, we develop the notion of an “economic bottleneck,” which defines resources as bottlenecks based on economic, rather than physical, characteristics.

  4. Bottleneck flows in networks

    CERN Document Server

    Punnen, Abraham P

    2007-01-01

    The bottleneck network flow problem (BNFP) is a generalization of several well-studied bottleneck problems such as the bottleneck transportation problem (BTP), bottleneck assignment problem (BAP), bottleneck path problem (BPP), and so on. In this paper we provide a review of important results on this topic and its various special cases. We observe that the BNFP can be solved as a sequence of $O(\\log n)$ maximum flow problems. However, special augmenting path based algorithms for the maximum flow problem can be modified to obtain algorithms for the BNFP with the property that these variations and the corresponding maximum flow algorithms have identical worst case time complexity. On unit capacity network we show that BNFP can be solved in $O(\\min \\{{m(n\\log n)}^{{2/3}}, m^{{3/2}}\\sqrt{\\log n}\\})$. This improves the best available algorithm by a factor of $\\sqrt{\\log n}$. On unit capacity simple graphs, we show that BNFP can be solved in $O(m \\sqrt {n \\log n})$ time. As a consequence we have an $O(m \\sqrt {n \\l...

  5. Effects of Bottlenecks in Vehicle Traffic

    CERN Document Server

    Yamamoto, S; Tadaki, S; Yamamoto, Syohei; Hieida, Yasuhiro; Tadaki, Shin-ichi

    2006-01-01

    Traffic congestion is usually observed at the upper streams of bottlenecks like tunnels. Congestion appears as stop-and-go waves and high density uniform flow. We perform simulations of traffic flow with a bottleneck using the coupled map optimal velocity model. The bottleneck is expressed as a road segment with speed reduction. The emergence of stop-and-go waves depends on the speed reduction in the bottleneck. A phenomenological theory of bottleneck effects is constructed.

  6. Mitigating SDN controller performance bottlenecks

    DEFF Research Database (Denmark)

    Caba, Cosmin Marius; Soler, José

    2015-01-01

    proposes a new approach for addressing the performance bottlenecks that arise from limited computational resources at the SDNC. The proposed approach is based on optimally configuring the operating parameters of the components residing inside the SDNC (network control functions such as monitoring, routing...

  7. Sales bottlenecks and their effect on profit

    NARCIS (Netherlands)

    Veltman, M.; Kooij, R.E.; Marban, S.

    2014-01-01

    This study introduces the term sales bottleneck, defined as a stage in a total production or service delivery process that limits sales. After analyzing the suitability of traditional methods to find sales bottlenecks, the study proposes the bottleneck accounting model as a method to determine sales

  8. MODIFIED BOTTLENECK-BASED PROCEDURE FOR LARGE-SCALE FLOW-SHOP SCHEDULING PROBLEMS WITH BOTTLENECK

    Institute of Scientific and Technical Information of China (English)

    ZUO Yan; GU Hanyu; XI Yugeng

    2006-01-01

    A new bottleneck-based heuristic for large-scale flow-shop scheduling problems with a bottleneck is proposed, which is simpler but more tailored than the shifting bottleneck (SB)procedure. In this algorithm, a schedule for the bottleneck machine is first constructed optimally and then the non-bottleneck machines are scheduled around the bottleneck schedule by some effective dispatching rules. Computational results show that the modified bottleneck-based procedure can achieve a tradeoff between solution quality and computational time comparing with SB procedure for medium-size problems. Furthermore it can obtain a good solution in quite short time for large-scale scheduling problems.

  9. Dynamic Prediction Method of Production Logistics Bottleneck Based on Bottleneck Index

    Institute of Scientific and Technical Information of China (English)

    LIU Mingzhou; TANG Juan; GE Maogen; JIANG Zengqiang; HU Jing; LING Lin

    2009-01-01

    In modern manufacturing pattern, there are many uncertain factors in the modern manufacturing process, such as changes of product attribute, changes of manufacturing resources' state, and so on, which cause production logistics bottleneck frequently shift, and make decisions of production planning and control based on formed bottleneck deviated from practical production process. Considering these factors, present researches mainly apply afterwards control to optimize production process to passively adapt to bottleneck changes. If the direction of bottleneck shifting can be accurately forecasted, the transition from afterwards control of chasing bottleneck to beforehand control can be realized. Therefore, aiming at the phenomenon of production logistics bottleneck shifting under uncertain manufacturing circumstances, this paper starts off with dynamic property of capability and requirement and then builds the concepts of bottleneck degree and bottleneck index to describe dynamic bottleneck characteristic of production unit;taken production capability, production load and quality assurance capability into consideration, mathematical model of bottleneck index is established to measure bottleneck degree accurately, consequently, quantitative research on mechanism of production logistics shifting is achieved. Based on bottleneck index, the prediction model of production logistics bottleneck is founded to predict dynamic change of bottleneck accurately. Finally, an example of forecasting and monitoring the production logistics bottleneck in one manufacturing shop is given to testify the validation and practicability of the prediction method.

  10. BOTTLENECKS IN PRODUCTION NETWORKS: AN OVERVIEW

    Institute of Scientific and Technical Information of China (English)

    Yongcai WANG; Qianchuan ZHAO; Dazhong ZHENG

    2005-01-01

    Bottlenecks, the key ingredients for improving the performances of the production networks,have been profoundly studied during the last decade. Yet, because of the complexity of the research results, there is still a significant gap between theory and practice. In this paper, we review various bottleneck definitions, detection methods and the asymptotic results and provide a practical guidance for recognizing and utilizing the bottlenecks in production networks. Queueing theory works as the mathematical foundation in our study. Various definitions of the bottlenecks are classified as either Performance in Processing (PIP) based or sensitivity based definitions, which reflect the preferences of the managers. Detection methods are surveyed closely based on the definitions. These methods are used to recognize the bottlenecks and to provide diagnosis results to managers. Comparisons show that different detection methods may lead to vastly different conclusions. The recognition of the bottlenecks has another advantage: the ultimate phenomena of the bottlenecks can greatly reduce the computation complexity in calculating the system performances. Bottlenecks based approximation and asymptotic results are studied to exhibit the contribution of bottlenecks in performance estimation and theoretical analysis.

  11. Analytical approach to continuous and intermittent bottleneck flows

    DEFF Research Database (Denmark)

    Helbing, D.; Johansson, A.; Mathiesen, Joachim Kaj;

    2006-01-01

    Many-particle-inspired theory, Continuous and Intermittent Bottleneck Flows Udgivelsesdato: Oct. 20......Many-particle-inspired theory, Continuous and Intermittent Bottleneck Flows Udgivelsesdato: Oct. 20...

  12. Cloud Technology May Widen Genomic Bottleneck - TCGA

    Science.gov (United States)

    Computational biologist Dr. Ilya Shmulevich suggests that renting cloud computing power might widen the bottleneck for analyzing genomic data. Learn more about his experience with the Cloud in this TCGA in Action Case Study.

  13. Anticipation Behavior Upstream of a Bottleneck

    NARCIS (Netherlands)

    Duives, D.C.; Daamen, W.; Hoogendoorn, S.P.

    2014-01-01

    Whether pedestrian movements do or do not follow similar patterns as vehicular traffic while experiencing congestion is not entirely understood. Using data gathered during bottleneck experiments under laboratory conditions, the phenomenon of anticipation before entering congestion is studied. This p

  14. Urban traffic congestion propagation and bottleneck identification

    Institute of Scientific and Technical Information of China (English)

    LONG JianCheng; GAO ZiYou; REN HuaLing; LIAN AiPing

    2008-01-01

    Bottlenecks in urban traffic network are sticking points in restricting network col-lectivity traffic efficiency.To identify network bottlenecks effectively is a founda-tional work for improving network traffic condition and preventing traffic conges-tion.In this paper,a congestion propagation model of urban network traffic is proposed based on the cell transmission model (CTM).The proposed model in-cludes a link model,which describes flow propagation on links,and a node model,which represents link-to-link flow propagation.A new method of estimating average journey velocity (AJV) of both link and network is developed to identify network congestion bottlenecks.A numerical example is studied in Sioux Falls urban traffic network.The proposed model is employed in simulating network traffic propaga-tion and congestion bottleneck identification under different traffic demands.The simulation results show that continual increase of traffic demand is an immediate factor in network congestion bottleneck emergence and increase as well as re-ducing network collectivity capability.Whether a particular link will become a bot-tleneck is mainly determined by its position in network,its traffic flow (attributed to different OD pairs) component,and network traffic demand.

  15. Tracing Road Network Bottleneck by Data Driven Approach

    Science.gov (United States)

    Qi, Hongsheng; Liu, Meiqi; Zhang, Lihui; Wang, Dianhai

    2016-01-01

    Urban road congestions change both temporally and spatially. They are essentially caused by network bottlenecks. Therefore, understanding bottleneck dynamics is critical in the goal of reasonably allocating transportation resources. In general, a typical bottleneck experiences the stages of formation, propagation and dispersion. In order to understand the three stages of a bottle neck and how the bottleneck moves on a road network, traffic flow data can be used to reconstruct these dynamics. However, raw traffic flow data is usually flawed in many ways. For instance some portion of data may be missing due to the failure of data collection devices, or some random factors in the data make it hard to identify real bottlenecks. In this paper a “user voting method” is proposed to deal with such raw-data-related issues. In this method, road links are ranked according to the weighed sum of certain performance measures and the links that are ranked relatively high are regarded as recurrent bottlenecks in a network, and several bottlenecks form a bottleneck area. A series of bottleneck parameters can be defined based on the identified bottleneck areas, such as bottleneck coverage, bottleneck link length, etc. Identifying bottleneck areas and calculating the bottleneck parameters for each time interval can reflect the evolution of the bottlenecks and also help trace how the bottlenecks move. PMID:27228150

  16. Tracing Road Network Bottleneck by Data Driven Approach.

    Science.gov (United States)

    Qi, Hongsheng; Liu, Meiqi; Zhang, Lihui; Wang, Dianhai

    2016-01-01

    Urban road congestions change both temporally and spatially. They are essentially caused by network bottlenecks. Therefore, understanding bottleneck dynamics is critical in the goal of reasonably allocating transportation resources. In general, a typical bottleneck experiences the stages of formation, propagation and dispersion. In order to understand the three stages of a bottle neck and how the bottleneck moves on a road network, traffic flow data can be used to reconstruct these dynamics. However, raw traffic flow data is usually flawed in many ways. For instance some portion of data may be missing due to the failure of data collection devices, or some random factors in the data make it hard to identify real bottlenecks. In this paper a "user voting method" is proposed to deal with such raw-data-related issues. In this method, road links are ranked according to the weighed sum of certain performance measures and the links that are ranked relatively high are regarded as recurrent bottlenecks in a network, and several bottlenecks form a bottleneck area. A series of bottleneck parameters can be defined based on the identified bottleneck areas, such as bottleneck coverage, bottleneck link length, etc. Identifying bottleneck areas and calculating the bottleneck parameters for each time interval can reflect the evolution of the bottlenecks and also help trace how the bottlenecks move. PMID:27228150

  17. Tracing Road Network Bottleneck by Data Driven Approach.

    Directory of Open Access Journals (Sweden)

    Hongsheng Qi

    Full Text Available Urban road congestions change both temporally and spatially. They are essentially caused by network bottlenecks. Therefore, understanding bottleneck dynamics is critical in the goal of reasonably allocating transportation resources. In general, a typical bottleneck experiences the stages of formation, propagation and dispersion. In order to understand the three stages of a bottle neck and how the bottleneck moves on a road network, traffic flow data can be used to reconstruct these dynamics. However, raw traffic flow data is usually flawed in many ways. For instance some portion of data may be missing due to the failure of data collection devices, or some random factors in the data make it hard to identify real bottlenecks. In this paper a "user voting method" is proposed to deal with such raw-data-related issues. In this method, road links are ranked according to the weighed sum of certain performance measures and the links that are ranked relatively high are regarded as recurrent bottlenecks in a network, and several bottlenecks form a bottleneck area. A series of bottleneck parameters can be defined based on the identified bottleneck areas, such as bottleneck coverage, bottleneck link length, etc. Identifying bottleneck areas and calculating the bottleneck parameters for each time interval can reflect the evolution of the bottlenecks and also help trace how the bottlenecks move.

  18. The Simulation Utilization for the Bottleneck Identification

    Directory of Open Access Journals (Sweden)

    Petra Vegnerová

    2009-12-01

    Full Text Available Advancing globalization increasingly leads to the creation of delivery systems. Increasing competition forces companies to reduce costs permanently. Both of these trends lead to the need to control material and information flows precisely. The target of this article is to describe and show one of ways of bottleneck determination in the supply system. This study deals with the computer simulation and its utilization for assessment of bottleneck. The foundation of the work is created a model of the supply system, it is used to compare the costs associated with the existence of stocks and stock levels in the individual partner of the system, depending on the location of the bottleneck. This article is published as a part of the research intention MSM 6046137306.

  19. Potential performance bottleneck in Linux TCP

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wenji; Crawford, Matt; /Fermilab

    2006-12-01

    TCP is the most widely used transport protocol on the Internet today. Over the years, especially recently, due to requirements of high bandwidth transmission, various approaches have been proposed to improve TCP performance. The Linux 2.6 kernel is now preemptible. It can be interrupted mid-task, making the system more responsive and interactive. However, we have noticed that Linux kernel preemption can interact badly with the performance of the networking subsystem. In this paper we investigate the performance bottleneck in Linux TCP. We systematically describe the trip of a TCP packet from its ingress into a Linux network end system to its final delivery to the application; we study the performance bottleneck in Linux TCP through mathematical modeling and practical experiments; finally we propose and test one possible solution to resolve this performance bottleneck in Linux TCP.

  20. Properties of Bottleneck on Complex Networks

    Institute of Scientific and Technical Information of China (English)

    WANG Chao-Yang; WU Jian-Jun; GAO Zi-You

    2011-01-01

    The traffic bottleneck plays a key role in most of the natural and artificial network.Here we present a simply model for bottleneck dynamical characteristics consideration the reliability on the complex network by taking into account the network topology characteristics and system size.We find that there is a critical rate of flow generation below which the network traffic is free but above which traffic congestion occurs.Also, it is found that random networks have larger critical flow generating rate than scale free ones.Analytical results may be practically useful for designing networks, especially for the urban traffic network.

  1. Reliability of genetic bottleneck tests for detecting recent population declines

    NARCIS (Netherlands)

    Peery, M. Zachariah; Kirby, Rebecca; Reid, Brendan N.; Stoelting, Ricka; Doucet-Beer, Elena; Robinson, Stacie; Vasquez-Carrillo, Catalina; Pauli, Jonathan N.; Palsboll, Per J.

    2012-01-01

    The identification of population bottlenecks is critical in conservation because populations that have experienced significant reductions in abundance are subject to a variety of genetic and demographic processes that can hasten extinction. Genetic bottleneck tests constitute an appealing and popula

  2. Performance Bottlenecks in Digital Movie Systems

    OpenAIRE

    Keller, Ralf; Effelsberg, Wolfgang; Lamparter, Bernd

    1993-01-01

    Digital movie systems offer great perspectives for multimedia applications. But the large amounts of data involved and the demand for isochronous transmission and playback are also great challenges for the designers of a new generation of file systems, database systems, operating systems, window systems, video encoder/decoder and networks. Today's research prototypes of digital movie systems suffer from severe performance bottlenecks, resulting in small movie windows, low frame rates or bad i...

  3. DYNAMIC BOTTLENECKS IN HANDLING AND STORAGE SYSTEMS

    OpenAIRE

    PANOVA YULIA; HILMOLA OLLI-PEKKA

    2015-01-01

    The development of industrial engineering and production systems is manifested under the demand of Russian customers in the current economic and political situation, e.g. deprivation from several import markets. In these circumstances, issues related to the formation of process systems are gaining their importance. The article considers the objective of reaching the smooth and continuous material flow in the handling and storage system of the plant, as well as the problems of bottlenecks opti...

  4. Individual Microscopic Results Of Bottleneck Experiments

    CERN Document Server

    Bukáček, Marek; Krbálek, Milan

    2016-01-01

    This contribution provides microscopic experimental study of pedestrian motion in front of the bottleneck, explains the high variance of individual travel time by the statistical analysis of trajectories. The analysis shows that this heterogeneity increases with increasing occupancy. Some participants were able to reach lower travel time due more efficient path selection and more aggressive behavior within the crowd. Based on this observations, linear model predicting travel time with respect to the aggressiveness of pedestrian is proposed.

  5. Bottlenecks to coral recovery in the Seychelles

    Science.gov (United States)

    Chong-Seng, K. M.; Graham, N. A. J.; Pratchett, M. S.

    2014-06-01

    Processes that affect recovery of coral assemblages require investigation because coral reefs are experiencing a diverse array of more frequent disturbances. Potential bottlenecks to coral recovery include limited larval supply, low rates of settlement, and high mortality of new recruits or juvenile corals. We investigated spatial variation in local abundance of scleractinian corals in the Seychelles at three distinct life history stages (recruits, juveniles, and adults) on reefs with differing benthic conditions. Following widespread coral loss due to the 1998 bleaching event, some reefs are recovering (i.e., relatively high scleractinian coral cover: `coral-dominated'), some reefs have low cover of living macrobenthos and unconsolidated rubble substrates (`rubble-dominated'), and some reefs have high cover of macroalgae (`macroalgal-dominated'). Rates of coral recruitment to artificial settlement tiles were similar across all reef conditions, suggesting that larval supply does not explain differential coral recovery across the three reef types. However, acroporid recruits were absent on macroalgal-dominated reefs (0.0 ± 0.0 recruits tile-1) in comparison to coral-dominated reefs (5.2 ± 1.6 recruits tile-1). Juvenile coral colony density was significantly lower on macroalgal-dominated reefs (2.4 ± 1.1 colonies m-2), compared to coral-dominated reefs (16.8 ± 2.4 m-2) and rubble-dominated reefs (33.1 ± 7.3 m-2), suggesting that macroalgal-dominated reefs have either a bottleneck to successful settlement on the natural substrates or a high post-settlement mortality bottleneck. Rubble-dominated reefs had very low cover of adult corals (10.0 ± 1.7 %) compared to coral-dominated reefs (33.4 ± 3.6 %) despite no statistical difference in their juvenile coral densities. A bottleneck caused by low juvenile colony survivorship on unconsolidated rubble-dominated reefs is possible, or alternatively, recruitment to rubble-dominated reefs has only recently begun. This

  6. A theory of traffic congestion at moving bottlenecks

    Science.gov (United States)

    Kerner, Boris S.; Klenov, Sergey L.

    2010-10-01

    The physics of traffic congestion occurring at a moving bottleneck on a multi-lane road is revealed based on the numerical analyses of vehicular traffic with a discrete stochastic traffic flow model in the framework of three-phase traffic theory. We find that there is a critical speed of a moving bottleneck at which traffic breakdown, i.e. a first-order phase transition from free flow to synchronized flow, occurs spontaneously at the moving bottleneck, if the flow rate upstream of the bottleneck is great enough. The greater the flow rate, the higher the critical speed of the moving bottleneck. A diagram of congested traffic patterns at the moving bottleneck is found, which shows regions in the flow-rate-moving-bottleneck-speed plane in which congested patterns emerge spontaneously or can be induced through large enough disturbances in an initial free flow. A comparison of features of traffic breakdown and resulting congested patterns at the moving bottleneck with known ones at an on-ramp (and other motionless) bottleneck is made. Nonlinear features of complex interactions and transformations of congested traffic patterns occurring at on- and off-ramp bottlenecks due to the existence of the moving bottleneck are found. The physics of the phenomenon of traffic congestion due to 'elephant racing' on a multi-lane road is revealed.

  7. Modified bottleneck-based heuristic for large-scale job-shop scheduling problems with a single bottleneck

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A modified bottleneck-based (MB) heuristic for large-scale job-shop scheduling problems with a welldefined bottleneck is suggested,which is simpler but more tailored than the shifting bottleneck (SB) procedure.In this algorithm,the bottleneck is first scheduled optimally while the non-bottleneck machines are subordinated around the solutions of the bottleneck schedule by some effective dispatching rules.Computational results indicate that the MB heuristic can achieve a better tradeoff between solution quality and computational time compared to SB procedure for medium-size problems.Furthermore,it can obtain a good solution in a short time for large-scale job-shop scheduling problems.

  8. Bimodal mesoporous silica with bottleneck pores.

    Science.gov (United States)

    Reber, M J; Brühwiler, D

    2015-11-01

    Bimodal mesoporous silica consisting of two sets of well-defined mesopores is synthesized by a partial pseudomorphic transformation of an ordered mesoporous starting material (SBA-15 type). The introduction of a second set of smaller mesopores (MCM-41 type) establishes a pore system with bottlenecks that restricts the access to the core of the bimodal mesoporous silica particles. The particle size and shape of the starting material are retained, but micropores present in the starting material disappear during the transformation, leading to a true bimodal mesoporous product. A varying degree of transformation allows the adjustment of the pore volume contribution of the two mesopore domains. Information on the accessibility of the mesopores is obtained by the adsorption of fluorescence-labeled poly(amidoamine) dendrimers and imaging by confocal laser scanning microscopy. This information is correlated with nitrogen sorption data to provide insights regarding the spatial distribution of the two mesopore domains. The bimodal mesoporous materials are excellent model systems for the investigation of cavitation effects in nitrogen desorption isotherms. PMID:26399172

  9. Deep bottleneck features for spoken language identification.

    Directory of Open Access Journals (Sweden)

    Bing Jiang

    Full Text Available A key problem in spoken language identification (LID is to design effective representations which are specific to language information. For example, in recent years, representations based on both phonotactic and acoustic features have proven their effectiveness for LID. Although advances in machine learning have led to significant improvements, LID performance is still lacking, especially for short duration speech utterances. With the hypothesis that language information is weak and represented only latently in speech, and is largely dependent on the statistical properties of the speech content, existing representations may be insufficient. Furthermore they may be susceptible to the variations caused by different speakers, specific content of the speech segments, and background noise. To address this, we propose using Deep Bottleneck Features (DBF for spoken LID, motivated by the success of Deep Neural Networks (DNN in speech recognition. We show that DBFs can form a low-dimensional compact representation of the original inputs with a powerful descriptive and discriminative capability. To evaluate the effectiveness of this, we design two acoustic models, termed DBF-TV and parallel DBF-TV (PDBF-TV, using a DBF based i-vector representation for each speech utterance. Results on NIST language recognition evaluation 2009 (LRE09 show significant improvements over state-of-the-art systems. By fusing the output of phonotactic and acoustic approaches, we achieve an EER of 1.08%, 1.89% and 7.01% for 30 s, 10 s and 3 s test utterances respectively. Furthermore, various DBF configurations have been extensively evaluated, and an optimal system proposed.

  10. Deep bottleneck features for spoken language identification.

    Science.gov (United States)

    Jiang, Bing; Song, Yan; Wei, Si; Liu, Jun-Hua; McLoughlin, Ian Vince; Dai, Li-Rong

    2014-01-01

    A key problem in spoken language identification (LID) is to design effective representations which are specific to language information. For example, in recent years, representations based on both phonotactic and acoustic features have proven their effectiveness for LID. Although advances in machine learning have led to significant improvements, LID performance is still lacking, especially for short duration speech utterances. With the hypothesis that language information is weak and represented only latently in speech, and is largely dependent on the statistical properties of the speech content, existing representations may be insufficient. Furthermore they may be susceptible to the variations caused by different speakers, specific content of the speech segments, and background noise. To address this, we propose using Deep Bottleneck Features (DBF) for spoken LID, motivated by the success of Deep Neural Networks (DNN) in speech recognition. We show that DBFs can form a low-dimensional compact representation of the original inputs with a powerful descriptive and discriminative capability. To evaluate the effectiveness of this, we design two acoustic models, termed DBF-TV and parallel DBF-TV (PDBF-TV), using a DBF based i-vector representation for each speech utterance. Results on NIST language recognition evaluation 2009 (LRE09) show significant improvements over state-of-the-art systems. By fusing the output of phonotactic and acoustic approaches, we achieve an EER of 1.08%, 1.89% and 7.01% for 30 s, 10 s and 3 s test utterances respectively. Furthermore, various DBF configurations have been extensively evaluated, and an optimal system proposed. PMID:24983963

  11. Critical Bottleneck Size for Jamless Particle Flows in Two Dimensions

    Science.gov (United States)

    Masuda, Takumi; Nishinari, Katsuhiro; Schadschneider, Andreas

    2014-04-01

    We propose a simple microscopic model for arching phenomena at bottlenecks. The dynamics of particles in front of a bottleneck is described by a one-dimensional stochastic cellular automaton on a semicircular geometry. The model reproduces oscillation phenomena due to the formation and collapsing of arches. It predicts the existence of a critical bottleneck size for continuous particle flows. The dependence of the jamming probability on the system size is approximated by the Gompertz function. The analytical results are in good agreement with simulations.

  12. Impacts of genetic bottlenecks on soybean genome diversity

    OpenAIRE

    Hyten, David L; Song, Qijian; Zhu, Youlin; Choi, Ik-Young; Nelson, Randall L.; Costa, Jose M.; Specht, James E; Shoemaker, Randy C.; Cregan, Perry B

    2006-01-01

    Soybean has undergone several genetic bottlenecks. These include domestication in Asia to produce numerous Asian landraces, introduction of relatively few landraces to North America, and then selective breeding over the past 75 years. It is presumed that these three human-mediated events have reduced genetic diversity. We sequenced 111 fragments from 102 genes in four soybean populations representing the populations before and after genetic bottlenecks. We show that soybean has lost many rare...

  13. Optimizing Database Architecture for the New Bottleneck: Memory Access

    OpenAIRE

    Manegold, Stefan; Boncz, Peter; Kersten, Martin

    2000-01-01

    In the past decade, advances in speed of commodity CPUs have far out-paced advances in memory latency. Main-memory access is therefore increasingly a performance bottleneck for many computer applications, including database systems. In this article, we use a simple scan test to show the severe impact of this bottleneck. The insights gained are translated into guidelines for database architecture; in terms of both data structures and algorithms. We discuss how vertically fragmented data struct...

  14. Database architecture optimized for the new bottleneck: Memory access

    OpenAIRE

    Boncz, Peter; Manegold, Stefan; Kersten, Martin

    1999-01-01

    In the past decade, advances in speed of commodity CPUs have far out-paced advances in memory latency. Main-memory access is therefore increasingly a performance bottleneck for many computer applications, including database systems. In this article, we use a simple scan test to show the severe impact of this bottleneck. The insights gained are translated into guidelines for database architecture; in terms of both data structures and algorithms. We discuss how vertically fragmented data struct...

  15. Bottlenecks in serial production lines: A system-theoretic approach

    Directory of Open Access Journals (Sweden)

    C.-T. Kuo

    1996-01-01

    Full Text Available In this work, a new definition of production systems bottlenecks is formulated and analyzed. Specifically, a machine is defined as the bottleneck if the sensitivity of the system's performance index to this machine's production rate in isolation is the largest. Although appealing from the systems point of view, this definition suffers a deficiency due to the fact that the sensitivities involved cannot be either measured on-line or efficiently calculated off-line. To avoid this, the paper develops a method based on indirect but real-time data. From this point of view, the main result of the work is as follows: The bottleneck machine in a serial production line can be identified by analyzing relationships between the so-called manufacturing blockage and manufacturing starvation of each machine. This leads to a simple rule for bottleneck identification. The rule requires neither the calculation of the production rate sensitivities nor the production rate itself. When the probabilities of manufacturing blockages and starvations are not available from on-line measurements, the paper presents their analytical estimates which, under certain conditions, can be used for bottleneck identification. Finally, a case study at an automotive component plant is described.

  16. Steady State of Pedestrian Flow in Bottleneck Experiments

    CERN Document Server

    Liao, Weichen; Seyfried, Armin; Chraibi, Mohcine; Drzycimski, Kevin; Zheng, Xiaoping; Zhao, Ying

    2015-01-01

    Experiments with pedestrians could depend strongly on initial conditions. Comparisons of the results of such experiments require to distinguish carefully between transient state and steady state. In this work, a feasible algorithm - Cumulative Sum Control Chart - is proposed and improved to automatically detect steady states from density and speed time series of bottleneck experiments. The threshold of the detection parameter in the algorithm is calibrated using an autoregressive model. Comparing the detected steady states with previous manually selected ones, the modified algorithm gives more reproducible results. For the applications, three groups of bottleneck experiments are analysed and the steady states are detected. The study about pedestrian flow shows that the difference between the flows in all states and in steady state mainly depends on the ratio of pedestrian number to bottleneck width. When the ratio is higher than a critical value (approximately 115 persons/m), the flow in all states is almost ...

  17. Research of Cruise Industry Development Bottlenecks In China

    Directory of Open Access Journals (Sweden)

    Ping Zhou

    2014-08-01

    Full Text Available Cruise industry is a comprehensive new industry, which has a strong impetus to the development of other industries. In recent years, as the explosive growth in cruise market, China has become a global rapidly-growing emerging cruise market. The cruise industry has begun transiting from infancy to the development phase, in all likelihood facing a number of bottlenecks problem. In this paper, the development trend of the cruise industry is first analyzed, then the bottlenecks of cruise industry are studied and finally some reasonable countermeasures and suggestions are put forward. By perfecting policy and legal, expanding industrial chain, diversifying investment mode, cultivating the market of consumer subjects, and establishing a scientific talents training mode of enterprise, the bottlenecks of cruise industry can be solved. This will consequently promote healthy and rapid development in cruise tourism industry, and give full play to the role of joint economy.

  18. Breaking the biomass bottleneck of the fossil free society

    DEFF Research Database (Denmark)

    Wenzel, Henrik

    be converted to high-density fuels for mobility purposes, and it is a key source of carbon feedstock All in all, everything points to the fact, that biomass (and agricultural land) may be a severe bottleneck in the fossil free society and that excessive use can have severe consequences for the world’s forest...... resources, the food sector and the poorest part of the world population. We can, however, break this bottleneck. First of all, we must seek further energy savings. Secondly, we need to look for ways to de-carbonize society. There is a growing consensus among energy scientists and energy planners...... by hydrogenation and CCR, can approximately five-double our biomass potential for providing storable and high-density fuels and carbon feedstock compared to the presently applied technologies for converting biomass to fuels and feedstock. This can fully and effectively break the biomass bottleneck of the fossil...

  19. Bottleneck Paths and Trees and Deterministic Graphical Games

    OpenAIRE

    Chechik, Shiri; Kaplan, Haim; Thorup, Mikkel; Zamir, Or; Zwick, Uri

    2016-01-01

    Gabow and Tarjan showed that the Bottleneck Path (BP) problem, i.e., finding a path between a given source and a given target in a weighted directed graph whose largest edge weight is minimized, as well as the Bottleneck spanning tree (BST) problem, i.e., finding a directed spanning tree rooted at a given vertex whose largest edge weight is minimized, can both be solved deterministically in O(m * log^*(n)) time, where m is the number of edges and n is the number of vertices in the graph. We p...

  20. Kinetic description of bottleneck effects in traffic flow

    Institute of Scientific and Technical Information of China (English)

    Peng ZHANG; Dong-yan WU; S. C. WONG; Yi-zhou TAO

    2009-01-01

    This paper deals with the effects of traffic bottlenecks using an extended Lighthill-Whitham-Richards (LWR) model. The solution structure is analytically indi-cated by the study of the Riemann problem characterized by a discontinuous flux. This leads to a typical solution describing a queue upstream of the bottleneck and its width and height, and informs the design of a 5-mapping algorithm. More significantly, it is found that the kinetic model is able to reproduce stop-and-go waves for a triangular fun-damental diagram. Some simulation examples, which are in agreement with the analytical solutions, are given to support these conclusions.

  1. The "Bottleneck" Behaviours in Linear FNNCs and Their Breakthrough

    Institute of Scientific and Technical Information of China (English)

    HUANG Deshuang

    1999-01-01

    The classification mechanisms of linear feed forward neural network classifiers (FNNC), whose hidden layer performs the Fisher lineartrans formation of the input patterns, under the supervision of outer-supervised signals are investigated. The "bottleneck" behavioursin linear FNNCs are observed and analyzed. In addition, the structure stabilities of the linear FNNCs are also discussed. It is pointed out that the key point to break through the "bottleneck" behaviours forlinear FNNCs is to change linear hidden neurons into nonlinear hiddenones. Finally, the experimental results, taking the parity 3 problem asexample, are given.

  2. Energetic bottlenecks and other design constraints in avian annual cycles

    NARCIS (Netherlands)

    Piersma, T

    2002-01-01

    The flexible phenotypes of birds and mammals often appear to represent adjustments to alleviate some energetic bottleneck or another. By increasing the size of the organs involved in digestion and assimilation of nutrients (gut and liver), an individual bird can increase its ability to process nutri

  3. The Case for a Gaian Bottleneck: The Biology of Habitability.

    Science.gov (United States)

    Chopra, Aditya; Lineweaver, Charles H

    2016-01-01

    The prerequisites and ingredients for life seem to be abundantly available in the Universe. However, the Universe does not seem to be teeming with life. The most common explanation for this is a low probability for the emergence of life (an emergence bottleneck), notionally due to the intricacies of the molecular recipe. Here, we present an alternative Gaian bottleneck explanation: If life emerges on a planet, it only rarely evolves quickly enough to regulate greenhouse gases and albedo, thereby maintaining surface temperatures compatible with liquid water and habitability. Such a Gaian bottleneck suggests that (i) extinction is the cosmic default for most life that has ever emerged on the surfaces of wet rocky planets in the Universe and (ii) rocky planets need to be inhabited to remain habitable. In the Gaian bottleneck model, the maintenance of planetary habitability is a property more associated with an unusually rapid evolution of biological regulation of surface volatiles than with the luminosity and distance to the host star.

  4. The bottleneck may be the solution, not the problem.

    Science.gov (United States)

    Lotem, Arnon; Kolodny, Oren; Halpern, Joseph Y; Onnis, Luca; Edelman, Shimon

    2016-01-01

    As a highly consequential biological trait, a memory "bottleneck" cannot escape selection pressures. It must therefore co-evolve with other cognitive mechanisms rather than act as an independent constraint. Recent theory and an implemented model of language acquisition suggest that a limit on working memory may evolve to help learning. Furthermore, it need not hamper the use of language for communication. PMID:27562516

  5. Bottlenecks reduction using superconductors in high voltage transmission lines

    Directory of Open Access Journals (Sweden)

    Daloub Labib

    2016-01-01

    Full Text Available Energy flow bottlenecks in high voltage transmission lines known as congestions are one of the challenges facing power utilities in fast developing countries. Bottlenecks occur in selected power lines when transmission systems are operated at or beyond their transfer limits. In these cases, congestions result in preventing new power supply contracts, infeasibility in existing contracts, price spike and market power abuse. The “Superconductor Technology” in electric power transmission cables has been used as a solution to solve the problem of bottlenecks in energy transmission at high voltage underground cables and overhead lines. The increase in demand on power generation and transmission happening due to fast development and linked to the intensive usage of transmission network in certain points, which in turn, lead to often frequent congestion in getting the required power across to where it is needed. In this paper, a bottleneck in high voltage double overhead transmission line with Aluminum Conductor Steel Reinforced was modeled using conductor parameters and replaced by Gap-Type Superconductor to assess the benefit of upgrading to higher temperature superconductor and obtain higher current carrying capacity. This proved to reduce the high loading of traditional aluminum conductors and allow more power transfer over the line using superconductor within the same existing right-of-way, steel towers, insulators and fittings, thus reducing the upgrade cost of building new lines.

  6. The Case for a Gaian Bottleneck: The Biology of Habitability.

    Science.gov (United States)

    Chopra, Aditya; Lineweaver, Charles H

    2016-01-01

    The prerequisites and ingredients for life seem to be abundantly available in the Universe. However, the Universe does not seem to be teeming with life. The most common explanation for this is a low probability for the emergence of life (an emergence bottleneck), notionally due to the intricacies of the molecular recipe. Here, we present an alternative Gaian bottleneck explanation: If life emerges on a planet, it only rarely evolves quickly enough to regulate greenhouse gases and albedo, thereby maintaining surface temperatures compatible with liquid water and habitability. Such a Gaian bottleneck suggests that (i) extinction is the cosmic default for most life that has ever emerged on the surfaces of wet rocky planets in the Universe and (ii) rocky planets need to be inhabited to remain habitable. In the Gaian bottleneck model, the maintenance of planetary habitability is a property more associated with an unusually rapid evolution of biological regulation of surface volatiles than with the luminosity and distance to the host star. PMID:26789354

  7. Congestion in a city with a central bottleneck

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Palma, André de

    2012-01-01

    We consider dynamic congestion in an urban setting where trip origins are spatially distributed. All travelers must pass through a downtown bottleneck in order to reach their destination in the CBD. Each traveler chooses departure time to maximize general concave scheduling utility. We find that...

  8. Mitigating the controller performance bottlenecks in Software Defined Networks

    DEFF Research Database (Denmark)

    Caba, Cosmin Marius; Soler, José

    2016-01-01

    proposes a new approach for addressing the performance bottlenecks that arise from limited computational resources at the SDNC. The proposed approach is based on optimally configuring the operating parameters of the components residing inside the SDNC (network control functions such as monitoring, routing...

  9. Congestion in a city with a central bottleneck

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Palma, André de

    2010-01-01

    We consider dynamic congestion in an urban setting where trip origins are spatially distributed. All travelers must pass through a downtown bottleneck in order to reach their destination in the CBD. Each traveler chooses departure time to maximize general concave scheduling utility. At equilibrium...

  10. On the inefficiency of equilibria in linear bottleneck congestion games

    NARCIS (Netherlands)

    Keijzer, B. de; Schäfer, G.; Telelis, O.; Kontogiannis, S.; Koutsoupias, E.; Spirakis, P.G.

    2010-01-01

    We study the inefficiency of equilibrium outcomes in bottleneck congestion games. These games model situations in which strategic players compete for a limited number of facilities. Each player allocates his weight to a (feasible) subset of the facilities with the goal to minimize the maximum (weigh

  11. Towards a microscopic understanding of the phonon bottleneck

    Science.gov (United States)

    Garanin, D. A.

    2007-03-01

    The problem of the phonon bottleneck in the relaxation of two-level systems (spins) to a narrow group of resonant phonons via emission-absorption processes is investigated from first principles. It is shown that the kinetic approach based on the Pauli master equation is invalid because of the narrow distribution of the phonons exchanging their energy with the spins. This results in a long-memory effect that can be best taken into account by introducing an additional dynamical variable corresponding to the nondiagonal matrix elements responsible for spin-phonon correlation. The resulting system of dynamical equations describes the phonon-bottleneck plateau in the spin excitation, as well as a gap in the spin-phonon spectrum, for any finite concentration of spins. On the other hand, it does not accurately render the line shape of emitted phonons and still needs improving.

  12. Reservoir computing and the Sooner-is-Better bottleneck.

    Science.gov (United States)

    Frank, Stefan L; Fitz, Hartmut

    2016-01-01

    Prior language input is not lost but integrated with the current input. This principle is demonstrated by "reservoir computing": Untrained recurrent neural networks project input sequences onto a random point in high-dimensional state space. Earlier inputs can be retrieved from this projection, albeit less reliably so as more input is received. The bottleneck is therefore not "Now-or-Never" but "Sooner-is-Better."

  13. Energetic bottlenecks and other design constraints in avian annual cycles

    OpenAIRE

    Piersma, T

    2002-01-01

    The flexible phenotypes of birds and mammals often appear to represent adjustments to alleviate some energetic bottleneck or another. By increasing the size of the organs involved in digestion and assimilation of nutrients (gut and liver), an individual bird can increase its ability to process nutrients, for example to quickly store fuel for onward flight. Similarly, an increase in the exercise organs (pectoral muscles and heart) enables a bird to increase its metabolic power for sustained fl...

  14. Linguistics, cognitive psychology, and the Now-or-Never bottleneck.

    Science.gov (United States)

    Endress, Ansgar D; Katzir, Roni

    2016-01-01

    Christiansen & Chater (C&C)'s key premise is that "if linguistic information is not processed rapidly, that information is lost for good" (sect. 1, para. 1). From this "Now-or-Never bottleneck" (NNB), C&C derive "wide-reaching and fundamental implications for language processing, acquisition and change as well as for the structure of language itself" (sect. 2, para. 10). We question both the premise and the consequentiality of its purported implications.

  15. Restricted Dynamic Programming Heuristic for Precedence Constrained Bottleneck Generalized TSP

    OpenAIRE

    Salii, Y.

    2015-01-01

    We develop a restricted dynamical programming heuristic for a complicated traveling salesman problem: a) cities are grouped into clusters, resp. Generalized TSP; b) precedence constraints are imposed on the order of visiting the clusters, resp. Precedence Constrained TSP; c) the costs of moving to the next cluster and doing the required job inside one are aggregated in a minimax manner, resp. Bottleneck TSP; d) all the costs may depend on the sequence of previously visited clusters, resp. Seq...

  16. Natural language processing and the Now-or-Never bottleneck.

    Science.gov (United States)

    Gómez-Rodríguez, Carlos

    2016-01-01

    Researchers, motivated by the need to improve the efficiency of natural language processing tools to handle web-scale data, have recently arrived at models that remarkably match the expected features of human language processing under the Now-or-Never bottleneck framework. This provides additional support for said framework and highlights the research potential in the interaction between applied computational linguistics and cognitive science. PMID:27561430

  17. Linguistics, cognitive psychology, and the Now-or-Never bottleneck.

    Science.gov (United States)

    Endress, Ansgar D; Katzir, Roni

    2016-01-01

    Christiansen & Chater (C&C)'s key premise is that "if linguistic information is not processed rapidly, that information is lost for good" (sect. 1, para. 1). From this "Now-or-Never bottleneck" (NNB), C&C derive "wide-reaching and fundamental implications for language processing, acquisition and change as well as for the structure of language itself" (sect. 2, para. 10). We question both the premise and the consequentiality of its purported implications. PMID:27561603

  18. Nonlocal bottleneck effect in two-dimensional turbulence

    OpenAIRE

    Biskamp, D.; Celani, A; E. Schwarz

    1998-01-01

    The bottleneck pileup in the energy spectrum is investigated for several two-dimensional (2D) turbulence systems by numerical simulation using high-order diffusion terms to amplify the effect, which is weak for normal diffusion. For 2D magnetohydrodynamic (MHD) turbulence, 2D electron MHD (EMHD) turbulence and 2D thermal convection, which all exhibit direct energy cascades, a nonlocal behavior is found resulting in a logarithmic enhancement of the spectrum.

  19. Metaheuristic procedures for the lexicographic bottleneck assembly line balancing problem

    OpenAIRE

    Pastor Moreno, Rafael; García Villoria, Alberto; Laguna, Manuel; Martí Cunquero, Rafael

    2015-01-01

    The goal of this work is to develop an improved procedure for the solution of the lexicographic bottleneck variant of the assembly line balancing problem (LB-ALBP). The objective of the LB-ALBP is to minimize the workload of the most heavily loaded workstation, followed by the workload of the second most heavily loaded workstation and so on. This problem-recently introduced to the literature (Pastor, 2011)-has practical relevance to manufacturing facilities. We design, implement and fine-tune...

  20. Bottleneck on Supply Chain of Organic Agricultural Products and Countermeasures

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-min

    2012-01-01

    Organic agriculture is one of successful models of low-carbon agriculture, and plays an important role in alleviating and adapting to climate change. However, the development of supply chain of organic agricultural products lags behind, which seriously restricts development of organic agricultural product market. In this paper, major models and bottleneck of supply chain of organic agricultural products are analyzed, and finally countermeasures are put forward.

  1. A Macro Model for Traffic Flow with Consideration of Static Bottleneck

    Institute of Scientific and Technical Information of China (English)

    唐铁桥; 李鹏; 吴永洪; 黄海军

    2012-01-01

    In this paper, we develop a macro model for traffic flow with consideration of static bottleneck to explore the impacts of static bottleneck on traffic flow. The analytical and numerical results show that the proposed model can qualitatively describe the equilibrium flux, uniform flow and small perturbation under the action of a static bottleneck.

  2. A recent bottleneck of Y chromosome diversity coincides with a global change in culture

    DEFF Research Database (Denmark)

    Monika, Karmin; Saag, Lauri; Vicente, Mario;

    2015-01-01

    the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males....

  3. ON THE BOTTLENECK CAPACITY EXPANSION PROBLEMS ON NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Yang Chao; Zhang Jianzhong

    2006-01-01

    This article considers a class of bottleneck capacity expansion problems. Such problems aim to enhance bottleneck capacity to a certain level with minimum cost. Given a network G(V, A,(-C)) consisting of a set of nodes V = {v1, v2,………, vn}, a set of arcs A(∪-){(vi, vj) | i = 1, 2,………, n; j = 1, 2,………, n} and a capacity vector (-C). The component (-C)ij of (-C) is the capacity of arc (vi, vj). Define the capacity of a subset A' of A as the minimum capacity of the arcs in A, the capacity of a family F of subsets of A is the maximum capacity of its members. There axe two types of expanding models. In the arc-expanding model, the unit cost to increase the capacity of arc (vi, vj) is wij. In the node-expanding model, it is assumed that the capacities of all arcs (vi, vi) which start at the same node vi should be increased by the same amount and that the unit cost to make such expansion is wi. This article considers three kinds of bottleneck capacity expansion problems (path,spanning arborescence and maximum flow) in both expanding models. For each kind of expansion problems, this article discusses the characteristics of the problems and presents several results on the complexity of the problems.

  4. Estimation of the bottleneck size in Florida panthers

    Science.gov (United States)

    Culver, M.; Hedrick, P.W.; Murphy, K.; O'Brien, S.; Hornocker, M.G.

    2008-01-01

    We have estimated the extent of genetic variation in museum (1890s) and contemporary (1980s) samples of Florida panthers Puma concolor coryi for both nuclear loci and mtDNA. The microsatellite heterozygosity in the contemporary sample was only 0.325 that in the museum samples although our sample size and number of loci are limited. Support for this estimate is provided by a sample of 84 microsatellite loci in contemporary Florida panthers and Idaho pumas Puma concolor hippolestes in which the contemporary Florida panther sample had only 0.442 the heterozygosity of Idaho pumas. The estimated diversities in mtDNA in the museum and contemporary samples were 0.600 and 0.000, respectively. Using a population genetics approach, we have estimated that to reduce either the microsatellite heterozygosity or the mtDNA diversity this much (in a period of c. 80years during the 20th century when the numbers were thought to be low) that a very small bottleneck size of c. 2 for several generations and a small effective population size in other generations is necessary. Using demographic data from Yellowstone pumas, we estimated the ratio of effective to census population size to be 0.315. Using this ratio, the census population size in the Florida panthers necessary to explain the loss of microsatellite variation was c .41 for the non-bottleneck generations and 6.2 for the two bottleneck generations. These low bottleneck population sizes and the concomitant reduced effectiveness of selection are probably responsible for the high frequency of several detrimental traits in Florida panthers, namely undescended testicles and poor sperm quality. The recent intensive monitoring both before and after the introduction of Texas pumas in 1995 will make the recovery and genetic restoration of Florida panthers a classic study of an endangered species. Our estimates of the bottleneck size responsible for the loss of genetic variation in the Florida panther completes an unknown aspect of this

  5. The bottleneck effect in three-dimensional turbulence simulations

    CERN Document Server

    Dobler, W; Yousef, T A; Brandenburg, A; Dobler, Wolfgang; Haugen, Nils Erland L.; Yousef, Tarek A.; Brandenburg, Axel

    2003-01-01

    At numerical resolutions around $512^3$ and above, three-dimensional energy spectra from turbulence simulations begin to show noticeably shallower spectra than $k^{-5/3}$ near the Kolmogorov dissipation wavenumber (`bottleneck effect'). This effect is shown to be significantly weaker in one-dimensional spectra like those obtained in wind tunnel turbulence. The difference can be understood in terms of the transformation between one-dimensional and three-dimensional energy spectra under the assumption that the turbulent velocity field is isotropic. Transversal and longitudinal energy spectra are similar and can both accurately be computed from the full three-dimensional spectra.

  6. Bottlenecks to vibrational energy flow in OCS: Structures and mechanisms

    CERN Document Server

    Paškauskas, R; Uzer, T

    2008-01-01

    Finding the causes for the nonstatistical vibrational energy relaxation in the planar carbonyl sulfide (OCS) molecule is a longstanding problem in chemical physics: Not only is the relaxation incomplete long past the predicted statistical relaxation time, but it also consists of a sequence of abrupt transitions between long-lived regions of localized energy modes. We report on the phase space bottlenecks responsible for this slow and uneven vibrational energy flow in this Hamiltonian system with three degrees of freedom. They belong to a particular class of two-dimensional invariant tori which are organized around elliptic periodic orbits. We relate the trapping and transition mechanisms with the linear stability of these structures.

  7. Give or take? Rewards vs. Charges for a Congested Bottleneck

    OpenAIRE

    Rouwendal, Jan; Erik T. Verhoef; Knockaert, Jasper

    2010-01-01

    This discussion paper resulted in a publication in 'Regional Science and Urban Economics', 42(1-2), 166-76.This paper analyzes the possibilities to relieve congestion using rewards instead of taxes, as well as combinations of rewards and taxes. The model considers a Vickrey-ADL model of bottleneck congestion with endogenous scheduling. With inelastic demand, a fine (time-varying) reward is equivalent to a fine toll, and to a continuum of combinations of time-varying tolls and rewards (includi...

  8. A lexisearch Algorithm for the Bottleneck Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Zakir H. Ahmed

    2010-02-01

    Full Text Available The Bottleneck Traveling Salesman Problem (BTSP is a variation of the well-known Traveling Salesman Problem in which the objective is to minimize the maximum lap (arc length in the tour of the salesman. In this paper, a lexisearch algorithm using adjacency representation for a tour has been developed for obtaining exact optimal solution to the problem. Then a comparative study has been carried out to show the efficiency of the algorithm as against existing exact algorithm for some randomly generated and TSPLIB instances of different sizes.

  9. A cellular automaton model for a bridge traffic bottleneck

    Institute of Scientific and Technical Information of China (English)

    Shifa Xiao; Lingjiang Kong; Muren Liu

    2005-01-01

    A cellular automaton (CA) model is proposed in this paper to analyze a bridge traffic bottleneck. The simulation results with this model show that there are several phase transitions in the traffic average density, velocity and flow for each lane under a periodic boundary condition. An unstable phase in the traffic average density and velocity for the upstream and downstream lanes of the bridge is shown in a range of initial traffic densities. The critical points of the phase transitions and the phenomenon of the unstable phase found in the simulation are also explained with the mean-field theory.

  10. OPTIMISATION OF JOB SHOP SCHEDULING USING SHIFTING BOTTLENECK TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Katuru Phani Raja Kumar

    2013-07-01

    Full Text Available In manufacturing system the problem of scheduling machines is a difficult task to reach the due date of the productivity. The Job Shop Scheduling have been solved by different algorithms and methods based on the sequence operation constraints and processing times for small size problems. The JSSP with m machines and n jobs is represented to determine an optimal solution by using the shortest processing time technique and Gantt chart is drawn to visually represent the total makespan. The shifting bottleneck method has been used to reduce the total flow time of the JSSP and arrive at an optimal solution.

  11. The Plasmodium bottleneck: malaria parasite losses in the mosquito vector

    Directory of Open Access Journals (Sweden)

    Ryan C Smith

    2014-08-01

    Full Text Available Nearly one million people are killed every year by the malaria parasite Plasmodium. Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission.

  12. A bottleneck model of set-specific capture.

    Directory of Open Access Journals (Sweden)

    Katherine Sledge Moore

    Full Text Available Set-specific contingent attentional capture is a particularly strong form of capture that occurs when multiple attentional sets guide visual search (e.g., "search for green letters" and "search for orange letters". In this type of capture, a potential target that matches one attentional set (e.g. a green stimulus impairs the ability to identify a temporally proximal target that matches another attentional set (e.g. an orange stimulus. In the present study, we investigated whether set-specific capture stems from a bottleneck in working memory or from a depletion of limited resources that are distributed across multiple attentional sets. In each trial, participants searched a rapid serial visual presentation (RSVP stream for up to three target letters (T1-T3 that could appear in any of three target colors (orange, green, or lavender. The most revealing findings came from trials in which T1 and T2 matched different attentional sets and were both identified. In these trials, T3 accuracy was lower when it did not match T1's set than when it did match, but only when participants failed to identify T2. These findings support a bottleneck model of set-specific capture in which a limited-capacity mechanism in working memory enhances only one attentional set at a time, rather than a resource model in which processing capacity is simultaneously distributed across multiple attentional sets.

  13. A bottleneck model of set-specific capture.

    Science.gov (United States)

    Moore, Katherine Sledge; Weissman, Daniel H

    2014-01-01

    Set-specific contingent attentional capture is a particularly strong form of capture that occurs when multiple attentional sets guide visual search (e.g., "search for green letters" and "search for orange letters"). In this type of capture, a potential target that matches one attentional set (e.g. a green stimulus) impairs the ability to identify a temporally proximal target that matches another attentional set (e.g. an orange stimulus). In the present study, we investigated whether set-specific capture stems from a bottleneck in working memory or from a depletion of limited resources that are distributed across multiple attentional sets. In each trial, participants searched a rapid serial visual presentation (RSVP) stream for up to three target letters (T1-T3) that could appear in any of three target colors (orange, green, or lavender). The most revealing findings came from trials in which T1 and T2 matched different attentional sets and were both identified. In these trials, T3 accuracy was lower when it did not match T1's set than when it did match, but only when participants failed to identify T2. These findings support a bottleneck model of set-specific capture in which a limited-capacity mechanism in working memory enhances only one attentional set at a time, rather than a resource model in which processing capacity is simultaneously distributed across multiple attentional sets.

  14. Size of genetic bottlenecks leading to virus fitness loss is determined by mean initial population fitness.

    OpenAIRE

    Novella, I S; Elena, S F; Moya, A.; Domingo, E; Holland, J J

    1995-01-01

    Genetic bottlenecks are important events in the genetic diversification of organisms and colonization of new ecological niches. Repeated bottlenecking of RNA viruses often leads to fitness losses due to the operation of Muller's ratchet. Herein we use vesicular stomatitis virus to determine the transmission population size which leads to fitness decreases of virus populations. Remarkably, the effective size of a genetic bottleneck associated with fitness loss is greater when the fitness of th...

  15. Traffic Flow States in a Freeway with Bottleneck

    Institute of Scientific and Technical Information of China (English)

    PENG Zi-Hui; SUN Gang; ZHU Jing-Yi

    2009-01-01

    The system of mixture of single lane and double lane is studied by a cellular automata model, which is developed by us based on the Nagel and Schreckenberg's models. We justify that the model can reach a stable states quickly. The density distributions of the stable state is presented for several cases, which illustrate the manner of the congestion. The relationship between the outflow rate and the total number of vehicles and that between the outflow rate and the density just before the bottleneck are both given. Comparing with the relationship that occurring in the granular flow, we conclude that the transition from the free traffic flow to the congested traffic flow can also be attributed to the abrupt variation through unstable flow state, which can naturally explain the discontinuities and the complex time variation behavior observed in the traffic flow experiments.

  16. Queuing model of a traffic bottleneck with bimodal arrival rate

    Science.gov (United States)

    Woelki, Marko

    2016-06-01

    This paper revisits the problem of tuning the density in a traffic bottleneck by reduction of the arrival rate when the queue length exceeds a certain threshold, studied recently for variants of totally asymmetric simple exclusion process (TASEP) and Burgers equation. In the present approach, a simple finite queuing system is considered and its contrasting “phase diagram” is derived. One can observe one jammed region, one low-density region and one region where the queue length is equilibrated around the threshold. Despite the simplicity of the model the physics is in accordance with the previous approach: The density is tuned at the threshold if the exit rate lies in between the two arrival rates.

  17. Genetic diversity and bottleneck studies in the Marwari horse breed

    Indian Academy of Sciences (India)

    A. K. Gupta; M. Chauhan; S. N. Tandon; Sonia

    2005-12-01

    Genetic diversity within the Marwari breed of horses was evaluated using 26 different microsatellite pairs with 48 DNA samples from unrelated horses. This molecular characterisation was undertaken to evaluate the problem of genetic bottlenecks also, if any, in this breed. The estimated mean (± s.e.) allelic diversity was 5.9 (± 2.24), with a total of 133 alleles. A high level of genetic variability within this breed was observed in terms of high values of mean (± s.e.) effective number of alleles (3.3 ± 1.27), observed heterozygosity (0.5306 ± 0.22), expected Levene’s heterozygosity (0.6612 ± 0.15), expected Nei’s heterozygosity (0.6535 ± 0.14), and polymorphism information content (0.6120 ± 0.03). Low values of Wright’s fixation index, $F_{\\text{IS}}$ (0.2433 ± 0.05) indicated low levels of inbreeding. This basic study indicated the existence of substantial genetic diversity in the Marwari horse population. No significant genotypic linkage disequilibrium was detected across the population, suggesting no evidence of linkage between loci. A normal ‘L’ shaped distribution of mode–shift test, non-significant heterozygote excess on the basis of different models, as revealed from Sign, Standardized differences and Wilcoxon sign rank tests as well as non-significant ratio value suggested that there was no recent bottleneck in the existing Marwari breed population, which is important information for equine breeders. This study also revealed that the Marwari breed can be differentiated from some other exotic breeds of horses on the basis of three microsatellite primers.

  18. Divergent evolution peaks under intermediate population bottlenecks during bacterial experimental evolution

    Science.gov (United States)

    Phillips, Robyn L.; Gifford, Danna R.; MacLean, R. Craig

    2016-01-01

    There is growing evidence that parallel molecular evolution is common, but its causes remain poorly understood. Demographic parameters such as population bottlenecks are predicted to be major determinants of parallelism. Here, we test the hypothesis that bottleneck intensity shapes parallel evolution by elucidating the genomic basis of adaptation to antibiotic-supplemented media in hundreds of populations of the bacterium Pseudomonas fluorescens Pf0-1. As expected, bottlenecking decreased the rate of phenotypic and molecular adaptation. Surprisingly, bottlenecking had no impact on the likelihood of parallel adaptive molecular evolution at a genome-wide scale. However, bottlenecking had a profound impact on the genes involved in antibiotic resistance. Specifically, under either intense or weak bottlenecking, resistance predominantly evolved by strongly beneficial mutations which provide high levels of antibiotic resistance. In contrast with intermediate bottlenecking regimes, resistance evolved by a greater diversity of genetic mechanisms, significantly reducing the observed levels of parallel genetic evolution. Our results demonstrate that population bottlenecking can be a major predictor of parallel evolution, but precisely how may be more complex than many simple theoretical predictions. PMID:27466449

  19. Divergent evolution peaks under intermediate population bottlenecks during bacterial experimental evolution.

    Science.gov (United States)

    Vogwill, Tom; Phillips, Robyn L; Gifford, Danna R; MacLean, R Craig

    2016-07-27

    There is growing evidence that parallel molecular evolution is common, but its causes remain poorly understood. Demographic parameters such as population bottlenecks are predicted to be major determinants of parallelism. Here, we test the hypothesis that bottleneck intensity shapes parallel evolution by elucidating the genomic basis of adaptation to antibiotic-supplemented media in hundreds of populations of the bacterium Pseudomonas fluorescens Pf0-1. As expected, bottlenecking decreased the rate of phenotypic and molecular adaptation. Surprisingly, bottlenecking had no impact on the likelihood of parallel adaptive molecular evolution at a genome-wide scale. However, bottlenecking had a profound impact on the genes involved in antibiotic resistance. Specifically, under either intense or weak bottlenecking, resistance predominantly evolved by strongly beneficial mutations which provide high levels of antibiotic resistance. In contrast with intermediate bottlenecking regimes, resistance evolved by a greater diversity of genetic mechanisms, significantly reducing the observed levels of parallel genetic evolution. Our results demonstrate that population bottlenecking can be a major predictor of parallel evolution, but precisely how may be more complex than many simple theoretical predictions. PMID:27466449

  20. Population Bottlenecks Increase Additive Genetic Variance But Do Not Break a Selection Limit in Rainforest Drosophila

    DEFF Research Database (Denmark)

    van Heerwaarden, Belinda; Willi, Yvonne; Kristensen, Torsten N;

    2008-01-01

    According to neutral quantitative genetic theory, population bottlenecks are expected to decrease standing levels of additive genetic variance of quantitative traits. However, some empirical and theoretical results suggest that, if nonadditive genetic effects influence the trait, bottlenecks may...... actually increase additive genetic variance. This has been an important issue in conservation genetics where it has been suggested that small population size might actually experience an increase rather than a decrease in the rate of adaptation. Here we test if bottlenecks can break a selection limit...... effects were responsible for the divergence in desiccation resistance between the original control and a bottlenecked line exhibiting increased additive genetic variance for desiccation resistance. However, when bottlenecked lines were selected for increased desiccation resistance, there was only a small...

  1. Bottleneck Analysis of the Minimum Coat Problem for the Generalized Network Based on Augmented Forest Structure

    Institute of Scientific and Technical Information of China (English)

    江永亨; 王军; 等

    2003-01-01

    The bottleneck analysis of the minimum coat problem for the generalized netwok(MCPGN) is discussed.The analysis is based on the network simplex algorithm,which gains negative cost graphs by constructing augmented forest structure,then augments flows on the negative cost graphs until the optimal revolution is gained Bottleneck structure is presented after analyzing the augmented forest structure.The negative cost augmented graphs are constructed with the bottleneck structure.The arcs that block the negative cost augmented graph are the elements of the bottleneck.The bottleneck analysis for the generalized circulation problem,the minimum circulation problem and the circulation problem are discussed respectively as the basal problems,then that for MCPGN is achieved.An example is presented at the end.

  2. Bottlenecks of motion processing during a visual glance: the leaky flask model.

    Directory of Open Access Journals (Sweden)

    Haluk Öğmen

    Full Text Available Where do the bottlenecks for information and attention lie when our visual system processes incoming stimuli? The human visual system encodes the incoming stimulus and transfers its contents into three major memory systems with increasing time scales, viz., sensory (or iconic memory, visual short-term memory (VSTM, and long-term memory (LTM. It is commonly believed that the major bottleneck of information processing resides in VSTM. In contrast to this view, we show major bottlenecks for motion processing prior to VSTM. In the first experiment, we examined bottlenecks at the stimulus encoding stage through a partial-report technique by delivering the cue immediately at the end of the stimulus presentation. In the second experiment, we varied the cue delay to investigate sensory memory and VSTM. Performance decayed exponentially as a function of cue delay and we used the time-constant of the exponential-decay to demarcate sensory memory from VSTM. We then decomposed performance in terms of quality and quantity measures to analyze bottlenecks along these dimensions. In terms of the quality of information, two thirds to three quarters of the motion-processing bottleneck occurs in stimulus encoding rather than memory stages. In terms of the quantity of information, the motion-processing bottleneck is distributed, with the stimulus-encoding stage accounting for one third of the bottleneck. The bottleneck for the stimulus-encoding stage is dominated by the selection compared to the filtering function of attention. We also found that the filtering function of attention is operating mainly at the sensory memory stage in a specific manner, i.e., influencing only quantity and sparing quality. These results provide a novel and more complete understanding of information processing and storage bottlenecks for motion processing.

  3. Eye shape and the nocturnal bottleneck of mammals.

    Science.gov (United States)

    Hall, Margaret I; Kamilar, Jason M; Kirk, E Christopher

    2012-12-22

    Most vertebrate groups exhibit eye shapes that vary predictably with activity pattern. Nocturnal vertebrates typically have large corneas relative to eye size as an adaptation for increased visual sensitivity. Conversely, diurnal vertebrates generally demonstrate smaller corneas relative to eye size as an adaptation for increased visual acuity. By contrast, several studies have concluded that many mammals exhibit typical nocturnal eye shapes, regardless of activity pattern. However, a recent study has argued that new statistical methods allow eye shape to accurately predict activity patterns of mammals, including cathemeral species (animals that are equally likely to be awake and active at any time of day or night). Here, we conduct a detailed analysis of eye shape and activity pattern in mammals, using a broad comparative sample of 266 species. We find that the eye shapes of cathemeral mammals completely overlap with nocturnal and diurnal species. Additionally, most diurnal and cathemeral mammals have eye shapes that are most similar to those of nocturnal birds and lizards. The only mammalian clade that diverges from this pattern is anthropoids, which have convergently evolved eye shapes similar to those of diurnal birds and lizards. Our results provide additional evidence for a nocturnal 'bottleneck' in the early evolution of crown mammals.

  4. HIV/AIDS: global trends, global funds and delivery bottlenecks

    Directory of Open Access Journals (Sweden)

    Hadingham Jacqui

    2005-08-01

    Full Text Available Abstract Globalisation affects all facets of human life, including health and well being. The HIV/AIDS epidemic has highlighted the global nature of human health and welfare and globalisation has given rise to a trend toward finding common solutions to global health challenges. Numerous international funds have been set up in recent times to address global health challenges such as HIV. However, despite increasingly large amounts of funding for health initiatives being made available to poorer regions of the world, HIV infection rates and prevalence continue to increase world wide. As a result, the AIDS epidemic is expanding and intensifying globally. Worst affected are undoubtedly the poorer regions of the world as combinations of poverty, disease, famine, political and economic instability and weak health infrastructure exacerbate the severe and far-reaching impacts of the epidemic. One of the major reasons for the apparent ineffectiveness of global interventions is historical weaknesses in the health systems of underdeveloped countries, which contribute to bottlenecks in the distribution and utilisation of funds. Strengthening these health systems, although a vital component in addressing the global epidemic, must however be accompanied by mitigation of other determinants as well. These are intrinsically complex and include social and environmental factors, sexual behaviour, issues of human rights and biological factors, all of which contribute to HIV transmission, progression and mortality. An equally important factor is ensuring an equitable balance between prevention and treatment programmes in order to holistically address the challenges presented by the epidemic.

  5. Information bottleneck based incremental fuzzy clustering for large biomedical data.

    Science.gov (United States)

    Liu, Yongli; Wan, Xing

    2016-08-01

    Incremental fuzzy clustering combines advantages of fuzzy clustering and incremental clustering, and therefore is important in classifying large biomedical literature. Conventional algorithms, suffering from data sparsity and high-dimensionality, often fail to produce reasonable results and may even assign all the objects to a single cluster. In this paper, we propose two incremental algorithms based on information bottleneck, Single-Pass fuzzy c-means (spFCM-IB) and Online fuzzy c-means (oFCM-IB). These two algorithms modify conventional algorithms by considering different weights for each centroid and object and scoring mutual information loss to measure the distance between centroids and objects. spFCM-IB and oFCM-IB are used to group a collection of biomedical text abstracts from Medline database. Experimental results show that clustering performances of our approaches are better than such prominent counterparts as spFCM, spHFCM, oFCM and oHFCM, in terms of accuracy. PMID:27260783

  6. Photonic ADC: overcoming the bottleneck of electronic jitter.

    Science.gov (United States)

    Khilo, Anatol; Spector, Steven J; Grein, Matthew E; Nejadmalayeri, Amir H; Holzwarth, Charles W; Sander, Michelle Y; Dahlem, Marcus S; Peng, Michael Y; Geis, Michael W; DiLello, Nicole A; Yoon, Jung U; Motamedi, Ali; Orcutt, Jason S; Wang, Jade P; Sorace-Agaskar, Cheryl M; Popović, Miloš A; Sun, Jie; Zhou, Gui-Rong; Byun, Hyunil; Chen, Jian; Hoyt, Judy L; Smith, Henry I; Ram, Rajeev J; Perrott, Michael; Lyszczarz, Theodore M; Ippen, Erich P; Kärtner, Franz X

    2012-02-13

    Accurate conversion of wideband multi-GHz analog signals into the digital domain has long been a target of analog-to-digital converter (ADC) developers, driven by applications in radar systems, software radio, medical imaging, and communication systems. Aperture jitter has been a major bottleneck on the way towards higher speeds and better accuracy. Photonic ADCs, which perform sampling using ultra-stable optical pulse trains generated by mode-locked lasers, have been investigated for many years as a promising approach to overcome the jitter problem and bring ADC performance to new levels. This work demonstrates that the photonic approach can deliver on its promise by digitizing a 41 GHz signal with 7.0 effective bits using a photonic ADC built from discrete components. This accuracy corresponds to a timing jitter of 15 fs - a 4-5 times improvement over the performance of the best electronic ADCs which exist today. On the way towards an integrated photonic ADC, a silicon photonic chip with core photonic components was fabricated and used to digitize a 10 GHz signal with 3.5 effective bits. In these experiments, two wavelength channels were implemented, providing the overall sampling rate of 2.1 GSa/s. To show that photonic ADCs with larger channel counts are possible, a dual 20-channel silicon filter bank has been demonstrated. PMID:22418205

  7. Photonic ADC: overcoming the bottleneck of electronic jitter.

    Science.gov (United States)

    Khilo, Anatol; Spector, Steven J; Grein, Matthew E; Nejadmalayeri, Amir H; Holzwarth, Charles W; Sander, Michelle Y; Dahlem, Marcus S; Peng, Michael Y; Geis, Michael W; DiLello, Nicole A; Yoon, Jung U; Motamedi, Ali; Orcutt, Jason S; Wang, Jade P; Sorace-Agaskar, Cheryl M; Popović, Miloš A; Sun, Jie; Zhou, Gui-Rong; Byun, Hyunil; Chen, Jian; Hoyt, Judy L; Smith, Henry I; Ram, Rajeev J; Perrott, Michael; Lyszczarz, Theodore M; Ippen, Erich P; Kärtner, Franz X

    2012-02-13

    Accurate conversion of wideband multi-GHz analog signals into the digital domain has long been a target of analog-to-digital converter (ADC) developers, driven by applications in radar systems, software radio, medical imaging, and communication systems. Aperture jitter has been a major bottleneck on the way towards higher speeds and better accuracy. Photonic ADCs, which perform sampling using ultra-stable optical pulse trains generated by mode-locked lasers, have been investigated for many years as a promising approach to overcome the jitter problem and bring ADC performance to new levels. This work demonstrates that the photonic approach can deliver on its promise by digitizing a 41 GHz signal with 7.0 effective bits using a photonic ADC built from discrete components. This accuracy corresponds to a timing jitter of 15 fs - a 4-5 times improvement over the performance of the best electronic ADCs which exist today. On the way towards an integrated photonic ADC, a silicon photonic chip with core photonic components was fabricated and used to digitize a 10 GHz signal with 3.5 effective bits. In these experiments, two wavelength channels were implemented, providing the overall sampling rate of 2.1 GSa/s. To show that photonic ADCs with larger channel counts are possible, a dual 20-channel silicon filter bank has been demonstrated.

  8. Analysis of registered CDM projects: potential removal of evidenced bottlenecks

    Energy Technology Data Exchange (ETDEWEB)

    Agosto, D.; Bombard, P.; Gostinelli, F.

    2007-07-01

    The Clean Development Mechanism (CDM) has developed during its first period of implementation, a distinctive set of patterns. The authors thought of concentrating on the CDM analysis in order to highlight potential remedies or reasons for given bottlenecks. In order to establish a sort of extensive SWOT analysis for CDMs, all the 356 projects actually (November 2006) registered at UNFCCC were examined, together with all the about 1000 PDDs presented to the UNFCCC but not registered yet. The CDM projects have been studied trying to cluster projects according to relevant characteristics, both from a technical and an economic point of view. Chosen indicators are meant to identify: more convenient/more diffused energy system for a CDM; reasons for a geographical distribution of different types of projects; potentials for a future exploitation of lower used technologies in CDM. Conclusions are drawn and appropriate tables and graphs presented. (1) the Baseline Emission Factor, combined to economic patterns, is the pivotal factor that characterizes both choices of host country and technology; (2) some technologies can exploit appropriately CDM scheme, whilst other technologies, are constrained by it. (3) there are still some important weak points: grouping of non Annex I countries; crediting period; criteria for the evaluation of sustainable development. (auth)

  9. Development of control strategy of variable speed limits for improving traffic operations at freeway bottlenecks

    Institute of Scientific and Technical Information of China (English)

    李志斌; 刘攀; 王炜; 徐铖铖

    2014-01-01

    A control strategy of variable speed limits (VSL) was developed to reduce the travel time at freeway recurrent bottleneck areas. The proposed control strategy particularly focused on preventing the capacity drop and increasing the discharge flow. A cell transmission model (CTM) was developed to evaluate the effects of the proposed VSL control strategy on the traffic operations. The results show that the total travel time is reduced by 25.5% and the delay is reduced by 56.1%. The average travel speed is increased by 34.3% and the queue length is reduced by 31.0%. The traffic operation is improved by the proposed VSL control strategy. The way to use the proposed VSL control strategy in different types of freeway bottlenecks was also discussed by considering different traffic flow characteristics. It is concluded that the VSL control strategy is effective for merge bottlenecks but is less effective for diverge bottlenecks.

  10. Circuit model for spin-bottleneck resistance in magnetic-tunnel-junction devices

    OpenAIRE

    Jungwirth, T.; MacDonald, A. H.

    1998-01-01

    Spin-bottlenecks are created in magnetic-tunnel-junction devices by spatial inhomogeneity in the relative resistances for up and down spins. We propose a simple electrical circuit model for these devices which incorporates spin-bottleneck effects and can be used to calculate their overall resistance and magnetoresistance. The model permits a simple understanding of the dependence of device magnetoresistance on spin diffusion lengths, tunneling magnetoresistance, and majority and minority spin...

  11. On the Accurate Identification of Network Paths Having a Common Bottleneck

    Directory of Open Access Journals (Sweden)

    Muhammad Murtaza Yousaf

    2013-01-01

    Full Text Available We present a new mechanism for detecting shared bottlenecks between end-to-end paths in a network. Our mechanism, which only needs one-way delays from endpoints as an input, is based on the well-known linear algebraic approach: singular value decomposition (SVD. Clusters of flows which share a bottleneck are extracted from SVD results by applying an outlier detection method. Simulations with varying topologies and different network conditions show the high accuracy of our technique.

  12. A Framework for Accelerating Bottlenecks in GPU Execution with Assist Warps

    OpenAIRE

    Vijaykumar, Nandita; Pekhimenko, Gennady; Jog, Adwait; Ghose, Saugata; Bhowmick, Abhishek; Ausavarangnirun, Rachata; Das, Chita; Kandemir, Mahmut; Mowry, Todd C.; Mutlu, Onur

    2016-01-01

    Modern Graphics Processing Units (GPUs) are well provisioned to support the concurrent execution of thousands of threads. Unfortunately, different bottlenecks during execution and heterogeneous application requirements create imbalances in utilization of resources in the cores. For example, when a GPU is bottlenecked by the available off-chip memory bandwidth, its computational resources are often overwhelmingly idle, waiting for data from memory to arrive. This work describes the Core-Assist...

  13. Analysis of the pedestrian arching at bottleneck based on a bypassing behavior model

    Science.gov (United States)

    Tang, Ming; Jia, Hongfei; Ran, Bin; Li, Jun

    2016-07-01

    A bypassing behavior model was proposed, in which the local optimal decision behavior in the strategy level was modeled in velocity-time domain, to describe how pedestrians bypass the local obstacles considering the relative speed. The model contains (1) pedestrian visual and contact information acquisition; (2) motion state prediction of the local obstacles based on the visual and contact information; (3) pedestrian bypass strategy modeling in the velocity-time domain; (4) moving and overlapping solution. In the numerical solution, velocity domain was divided into n equal angle, the value of n ranges from 2 to infinity, the Manhattan space was refined gradually to Euclid Space accordingly, in which the movement of pedestrians was described. The model was applied to the analysis of pedestrian arching at the bottleneck in the emergent evacuation situation. (1) The results showed that the formation of the pedestrian arching at the bottleneck was deformation pressure, because many pedestrians try to pass through the bottleneck simultaneously, even in the absence of friction, the pedestrian arching still occurs; (2) In the emergent situation, we are more concerned about the bottleneck attribution of resistance to form the arching, the calculation and simulation results showed that the probability of an arching and the bottleneck width is an exponential function relationship, so when the stampede occurs in the middle of the bottleneck, the probability of arching will increase exponentially.

  14. Central as well as peripheral attentional bottlenecks in dual-task performance activate lateral prefrontal cortices

    Directory of Open Access Journals (Sweden)

    Andre J Szameitat

    2016-03-01

    Full Text Available Human information processing suffers from severe limitations in parallel processing. In particular, when required to respond to two stimuli in rapid succession, processing bottlenecks may appear at central and peripheral stages of task processing. Importantly, it has been suggested that executive functions are needed to resolve the interference arising at such bottlenecks. The aims of the present study were to test whether central attentional limitations (i.e., bottleneck at the decisional response selection stage as well as peripheral limitations (i.e., bottleneck at response initiation both demand executive functions located in the lateral prefrontal cortex. For this, we re-analysed two previous studies, in which a total of 33 participants performed a dual-task according to the paradigm of the psychological refractory period (PRP during fMRI. In one study (N=17, the PRP task consisted of two two-choice response tasks known to suffer from a central bottleneck (CB group. In the other study (N=16, the PRP task consisted of two simple-response tasks known to suffer from a peripheral bottleneck (PB group. Both groups showed considerable dual-task costs in form of slowing of the second response in the dual-task (PRP effect. Imaging results are based on the subtraction of both single-tasks from the dual-task within each group. In the CB group, the bilateral middle frontal gyri and inferior frontal gyri were activated. Higher activation in these areas was associated with lower dual-task costs. In the PB group, the right middle frontal and inferior frontal gyrus were activated. Here, higher activation was associated with higher dual-task costs. In conclusion we suggest that central and peripheral bottlenecks both demand executive functions located in lateral prefrontal cortices. Differences between the CB and PB groups with respect to the exact prefrontal areas activated and the correlational patterns suggest that the executive functions resolving

  15. Bottlenecks and Hubs in Inferred Networks Are Important for Virulence in Salmonella typhimurium

    Energy Technology Data Exchange (ETDEWEB)

    McDermott, Jason E.; Taylor, Ronald C.; Yoon, Hyunjin; Heffron, Fred

    2009-02-01

    Recent advances in experimental methods have provided sufficient data to consider systems as large networks of interconnected components. High-throughput determination of protein-protein interaction networks has led to the observation that topological bottlenecks, that is proteins defined by high centrality in the network, are enriched in proteins with systems-level phenotypes such as essentiality. Global transcriptional profiling by microarray analysis has been used extensively to characterize systems, for example, cellular response to environmental conditions and genetic mutations. These transcriptomic datasets have been used to infer regulatory and functional relationship networks based on co-regulation. We use the context likelihood of relatedness (CLR) method to infer networks from two datasets gathered from the pathogen Salmonella typhimurium; one under a range of environmental culture conditions and the other from deletions of 15 regulators found to be essential in virulence. Bottleneck nodes were identified from these inferred networks and we show that these nodes are significantly more likely to be essential for virulence than their non-bottleneck counterparts. A network generated using Pearson correlation did not display this behavior. Overall this study demonstrates that topology of networks inferred from global transcriptional profiles provides information about the systems-level roles of bottleneck genes. Analysis of the differences between the two CLR-derived networks suggests that the bottleneck nodes are either mediators of transitions between system states or sentinels that reflect the dynamics of these transitions.

  16. Bottlenecks and hubs in inferred networks are important for virulence in Salmonella typhimurium.

    Science.gov (United States)

    McDermott, Jason E; Taylor, Ronald C; Yoon, Hyunjin; Heffron, Fred

    2009-02-01

    Recent advances in experimental methods have provided sufficient data to consider systems as large networks of interconnected components. High-throughput determination of protein-protein interaction networks has led to the observation that topological bottlenecks, proteins defined by high centrality in the network, are enriched in proteins with systems-level phenotypes such as essentiality. Global transcriptional profiling by microarray analysis has been used extensively to characterize systems, for example, examining cellular response to environmental conditions and effects of genetic mutations. These transcriptomic datasets have been used to infer regulatory and functional relationship networks based on co-regulation. We use the context likelihood of relatedness (CLR) method to infer networks from two datasets gathered from the pathogen Salmonella typhimurium: one under a range of environmental culture conditions and the other from deletions of 15 regulators found to be essential in virulence. Bottleneck and hub genes were identified from these inferred networks, and we show for the first time that these genes are significantly more likely to be essential for virulence than their non-bottleneck or non-hub counterparts. Networks generated using simple similarity metrics (correlation and mutual information) did not display this behavior. Overall, this study demonstrates that topology of networks inferred from global transcriptional profiles provides information about the systems-level roles of bottleneck genes. Analysis of the differences between the two CLR-derived networks suggests that the bottleneck nodes are either mediators of transitions between system states or sentinels that reflect the dynamics of these transitions.

  17. Study on traffic characteristics for a typical expressway on-ramp bottleneck considering various merging behaviors

    Science.gov (United States)

    Sun, Jie; Li, Zhipeng; Sun, Jian

    2015-12-01

    Recurring bottlenecks at freeway/expressway are considered as the main cause of traffic congestion in urban traffic system while on-ramp bottlenecks are the most significant sites that may result in congestion. In this paper, the traffic bottleneck characteristics for a simple and typical expressway on-ramp are investigated by the means of simulation modeling under the open boundary condition. In simulations, the running behaviors of each vehicle are described by a car-following model with a calibrated optimal velocity function, and lane changing actions at the merging section are modeled by a novel set of rules. We numerically derive the traffic volume of on-ramp bottleneck under different upstream arrival rates of mainline and ramp flows. It is found that the vehicles from the ramp strongly affect the pass of mainline vehicles and the merging ratio changes with the increasing of ramp vehicle, when the arrival rate of mainline flow is greater than a critical value. In addition, we clarify the dependence of the merging ratio of on-ramp bottleneck on the probability of lane changing and the length of the merging section, and some corresponding intelligent control strategies are proposed in actual traffic application.

  18. Selectivity of fish ladders: a bottleneck in Neotropical fish movement

    Directory of Open Access Journals (Sweden)

    Carlos Sérgio Agostinho

    2007-01-01

    their proportions in the downriver stretch: fish samples in the ladder were clearly dominated by a few species, including some that do not need to be translocated. Thus, selectivity constitutes an important bottleneck to initiatives for translocating fish aimed at conserving their stocks or biodiversity. It is urgent to review the decision-making process for the construction of fish passages and to evaluate the functioning of those already operating.Dezenas de escadas de peixes foram construídas em barragens de reservatórios brasileiros, mas são raros os estudos acerca de suas eficiências como instrumentos de conservação da ictiofauna Neotropical, em especial de espécies migradoras. Neste contexto, o presente estudo teve como objetivo avaliar a seletividade específica no ingresso e ascensão de peixes na escada localizada junto à barragem de Lajeado (UHE Luis Eduardo Magalhães, rio Tocantins. Amostragens foram realizadas mensalmente de novembro de 2002 a outubro de 2003 nos tanques de descanso da escada, utilizando tarrafas, e no trecho a jusante, utilizando redes de espera. A avaliação da seletividade no ingresso da escada foi realizada através da comparação da ocorrência, abundância relativa, dominância e congruência dos ranks de abundância de espécies migradoras e não migradoras na escada e no trecho imediatamente a jusante. A riqueza e abundância específica nos diferentes tanques de descanso foram utilizadas para avaliar a seletividade ao longo da escada. Os efeitos das variações temporais do nível hidrométrico de jusante e da velocidade de fluxo na seletividade foram também analisados. Das 130 espécies registradas a jusante, 63,2% foram capturadas na escada, com claro favorecimento das espécies migradoras. Entretanto, mais de 2/3 das capturas pertenceram a apenas três espécies (Rhaphiodon vulpinus, Psectrogaster amazonica e Oxydoras niger. Embora a maioria das espécies que ingressa na escada possa alcançar seu topo, constatou

  19. A recent bottleneck of Y chromosome diversity coincides with a global change in culture

    KAUST Repository

    Karmin, Monika

    2015-04-30

    It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50–100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192–307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47–52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males.

  20. Effects of speed bottleneck on traffic flow with feedback control signal

    Science.gov (United States)

    Zhu, Kangli; Bi, Jiantao; Wu, Jianjun; Li, Shubin

    2016-09-01

    Various car-following models (CMs) have been developed to capture the complex characteristics of microscopic traffic flow, among which the coupled map CM can better reveal and reflect various phenomena of practical traffic flow. Capacity change at bottleneck contributes to high-density traffic flow upstream the bottleneck and contains very complex dynamic behavior. In this paper, we analyze the effect of speed bottleneck on the spatial-temporal evolution characteristics of traffic flow, and propose a method to reduce traffic congestion with the feedback control signal based on CM. Simulation results highlight the potential of using the feedback signal to control the stop-and-go wave and furthermore to alleviate the traffic congestion effectively.

  1. "BOTTLENECK" AND COUNTERMEASURE OF HIGH-TECHNOLOGIZATION OF MARINE INDUSTRY IN CHINA

    Institute of Scientific and Technical Information of China (English)

    LUAN Wei-xin

    2004-01-01

    This article deeply researched into the existent five problems and four main "bottlenecks" in the high-technologization of marine industry in China on the basis of analyzing the new trends in international marine problems and the necessity of implementing the strategy of developing China based on marine. This article brought up specific measures to the five "bottlenecks" according to the situations, and pointed out that new marine industry should be high-technologization and the traditional marine industry should be reformed by high-technique. The research results may provide the scientific basis for realizing the high-technologization of marine industry in China.

  2. Bottlenecks, population differentiation and apparent selection at microsatellite loci in Australian Drosophila buzzatii

    DEFF Research Database (Denmark)

    Barker, J.S.F.; Frydenberg, Jane; González, J.;

    2009-01-01

    variation for 15 microsatellite loci in each of nine populations in eastern Australia was used to estimate the size of the bottleneck, and to determine if any of these microsatellites marked genomic regions subject to recent selection. We estimate that on its introduction to Australia, D. buzzatii went...... through a moderate bottleneck (approximately 30-40 founders). Linkage disequilibrium was common, both intrachromosomal and between loci on different chromosomes. Of the 15 loci, 2 showed evidence of selection, one exhibiting local adaptation in different populations and the other balancing selection. We...

  3. Reducing the Analytical Bottleneck for Domain Scientists: Lessons from a Climate Data Visualization Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Aritra; Poco, Jorge; Bertini, Enrico; Silva, Claudio T.

    2016-01-31

    The gap between large-scale data production rate and the rate of generation of data-driven scientific insights has led to an analytical bottleneck in scientific domains like climate, biology, etc. This is primarily due to the lack of innovative analytical tools that can help scientists efficiently analyze and explore alternative hypotheses about the data, and communicate their findings effectively to a broad audience. In this paper, by reflecting on a set of successful collaborative research efforts between with a group of climate scientists and visualization researchers, we introspect how interactive visualization can help reduce the analytical bottleneck for domain scientists.

  4. Research on polymorphism of production logistics bottleneck based on bottleneck index%基于瓶颈指数的生产物流瓶颈多态性研究

    Institute of Scientific and Technical Information of China (English)

    唐娟; 刘志

    2011-01-01

    Aiming at the shifting phenomenon of production logistics in the manufacturing shop under uncertain environments, the conceptual model which is composed of main bottleneck, second bottleneck, sensitive bottleneck and insensitive bottleneck is built;taken production capability,production load,quality assurance capability and production cost of manufacturing unit into con-sideration ,mathematical model of bottleneck index is established to measure bottleneck degree accurately;based on bottleneck in-dex, the prediction mechanism is established to identify bottleneck and non-bottleneck,main bottleneck and second bottleneck, then sensitive coefficient of bottleneck shifting is founded to accurately judge sensitive bottleneck and insensitive bottleneck of the manufacturing shop,which provide a method support for forecasting and monitoring the phenomenon of bottleneck shifting.%针对不确定性环境下制造车间生产物流瓶颈漂移现象,建立以主瓶颈、次瓶颈、灵敏型瓶颈和迟钝型瓶颈为主的瓶颈多态性概念模型;综合考虑制造单元的生产能力、生产负荷、质量保证能力和生产成本,构建瓶颈指数数学模型,以实现制造单元瓶颈度的准确度量;以瓶颈指数为基础,构建瓶颈及主次瓶颈的预测机制,并构建瓶颈漂移敏感系数,以实现制造车间生产物流瓶颈与非瓶颈、主瓶颈和次瓶颈、灵敏型瓶颈和迟钝型瓶颈的准确判别,进而为实现瓶颈漂移现象的预测和监控提供一种方法.

  5. About the Role of the Bottleneck/Cork Interface on Oxygen Transfer.

    Science.gov (United States)

    Lagorce-Tachon, Aurélie; Karbowiak, Thomas; Paulin, Christian; Simon, Jean-Marc; Gougeon, Régis D; Bellat, Jean-Pierre

    2016-09-01

    The transfer of oxygen through a corked bottleneck was investigated using a manometric technique. First, the effect of cork compression on oxygen transfer was evaluated without considering the glass/cork interface. No significant effect of cork compression (at 23% strain, corresponding to the compression level of cork in a bottleneck for still wines) was noticeable on the effective diffusion coefficient of oxygen. The mean value of the effective diffusion coefficient is equal to 10(-8) m(2) s(-1), with a statistical distribution ranging from 10(-10) to 10(-7) m(2) s(-1), which is of the same order of magnitude as for the non-compressed cork. Then, oxygen transfer through cork compressed in a glass bottleneck was determined to assess the effect of the glass/cork interface. In the particular case of a gradient-imposed diffusion of oxygen through our model corked bottleneck system (dry cork without surface treatment; 200 and ∼0 hPa of oxygen on both sides of the sample), the mean effective diffusion coefficient is of 5 × 10(-7) m(2) s(-1), thus revealing the possible importance of the role of the glass/stopper interface in the oxygen transfer.

  6. Self-organized phenomena of pedestrian counterflow through a wide bottleneck in a channel

    Science.gov (United States)

    Dong, Li-Yun; Lan, Dong-Kai; Li, Xiang

    2016-09-01

    The pedestrian counterflow through a bottleneck in a channel shows a variety of flow patterns due to self-organization. In order to reveal the underlying mechanism, a cellular automaton model was proposed by incorporating the floor field and the view field which reflects the global information of the studied area and local interactions with others. The presented model can well reproduce typical collective behaviors, such as lane formation. Numerical simulations were performed in the case of a wide bottleneck and typical flow patterns at different density ranges were identified as rarefied flow, laminar flow, interrupted bidirectional flow, oscillatory flow, intermittent flow, and choked flow. The effects of several parameters, such as the size of view field and the width of opening, on the bottleneck flow are also analyzed in detail. The view field plays a vital role in reproducing self-organized phenomena of pedestrian. Numerical results showed that the presented model can capture key characteristics of bottleneck flows. Project supported by the National Basic Research Program of China (Grant No. 2012CB725404) and the National Natural Science Foundation of China (Grant Nos. 11172164 and 11572184).

  7. Maternal age effect and severe germ-line bottleneck in the inheritance of human mitochondrial DNA

    DEFF Research Database (Denmark)

    Rebolledo-Jaramillo, Boris; Su, Marcia Shu-Wei; Stoler, Nicholas;

    2014-01-01

    The manifestation of mitochondrial DNA (mtDNA) diseases depends on the frequency of heteroplasmy (the presence of several alleles in an individual), yet its transmission across generations cannot be readily predicted owing to a lack of data on the size of the mtDNA bottleneck during oogenesis...

  8. Temperature dependence of the polariton relaxation bottleneck in a GaN microcavity

    Energy Technology Data Exchange (ETDEWEB)

    Stokker-Cheregi, F. [LENS and Department of Physics, University of Florence (Italy); NILPRP, Lasers Department, Magurele, Bucharest (Romania); Vinattieri, A.; Colocci, M.; Gurioli, M. [LENS and Department of Physics, University of Florence (Italy); Semond, F.; Leroux, M.; Massies, J. [CRHEA-CNRS, Valbonne (France); Sellers, I.R. [CRHEA-CNRS, Valbonne (France); Department of Physics, University of Buffalo, NY (United States)

    2008-07-01

    We present an experimental study aimed to investigate discuss the possible presence of a phonon bottleneck in a GaN bulk microcavity. Clear anticrossing between the lower (LP) and upper polariton (UP) branches has been observed up to room temperature in photoluminescence (PL) by angular measurements with a Rabi splitting of the order of 30 meV. In order to determine the presence of a relaxation bottleneck, angular PL measurements have been performed at different temperatures for negative detuning. At low T the PL shows a clear maximum, at the angle corresponding to the resonance between the exciton and the photon modes, which is an experimental demonstration of the presence of a relaxation bottleneck. The PL enhancement in resonance condition is suppressed with increasing T and it almost disappears at room temperature. We therefore demonstrate that the exciton-phonon interaction washes out the polariton bottleneck in GaN MCs at room temperature. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Identifikasi Bottleneck pada Hasil Ekstraksi Proses Bisnis ERP dengan Membandingkan Algoritma Alpha++ dan Heuristics Miner

    Directory of Open Access Journals (Sweden)

    Laeila Mardhatillah

    2012-09-01

    Full Text Available Saat ini banyak perusahaan menggunakan sistem informasi untuk menunjang proses bisnis. Namun kenyataannya hanya beberapa perusahaan yang melakukan evaluasi untuk proses bisnis pada sistem informasi tersebut. Evaluasi ini didapat dari data Event log yang merupakan hasil proses ekstrasi ERP. Cara melakukan evaluasi yaitu dengan process mining. Process mining berfungsi untuk menggali proses transaksi sehingga terbentuk suatu workflow proses bisnis yang actual. Workflow proses bisnis ini akan digambarkan dalam bentuk Petri Net, selanjutnya dari Petri Net inilah akan dilakukan analisis untuk mengidentifikasi adanya BottleneckBottleneck merupakan peristiwa pada suatu transaksi yang memiliki waktu tunggu yang lebih lama dibandingkan transaksi lainnya dalam suatu proses bisnis. Dengan adanya PROM Tools maka penggambaran mengenai proses bisnis ERP dapat terbentuk. Penggambaran model tersebut menggunakan dua algoritma, yaitu Algoritma Alpha ++ dan Heuristics Miner. Kedua algoritma ini digunakan untuk mencari perbedaan bottleneck yang terjadi. Dari penelitian didapatkan  hasil bahwa algoritma sangat mempengaruhi letak bottleneck. Letak tersebut didasarkan pada perhitungan waktu token yang ada pada place (tempat antara dua transisi atau dua transaksi saat terbentuk model.

  10. Consequences of the Now-or-Never bottleneck for signed versus spoken languages.

    Science.gov (United States)

    Emmorey, Karen

    2016-01-01

    Signed and spoken languages emerge, change, are acquired, and are processed under distinct perceptual, motor, and memory constraints. Therefore, the Now-or-Never bottleneck has different ramifications for these languages, which are highlighted in this commentary. The extent to which typological differences in linguistic structure can be traced to processing differences provides unique evidence for the claim that structure is processing. PMID:27562833

  11. Evaluation of bottlenecks in the late stages of protein secretion in Bacillus subtilis

    NARCIS (Netherlands)

    Bolhuis, A; Tjalsma, H; Smith, H.E; Meima, R.; Venema, G; Bron, S; van Dijl, J.M

    1999-01-01

    Despite a high capacity for secretion of homologous proteins, the secretion of heterologous proteins by Bacillus subtilis is frequently inefficient. In the present studies, we have investigated and compared bottlenecks in the secretion of four heterologous proteins: Bacillus lichenifomis alpha-amyla

  12. About the Role of the Bottleneck/Cork Interface on Oxygen Transfer.

    Science.gov (United States)

    Lagorce-Tachon, Aurélie; Karbowiak, Thomas; Paulin, Christian; Simon, Jean-Marc; Gougeon, Régis D; Bellat, Jean-Pierre

    2016-09-01

    The transfer of oxygen through a corked bottleneck was investigated using a manometric technique. First, the effect of cork compression on oxygen transfer was evaluated without considering the glass/cork interface. No significant effect of cork compression (at 23% strain, corresponding to the compression level of cork in a bottleneck for still wines) was noticeable on the effective diffusion coefficient of oxygen. The mean value of the effective diffusion coefficient is equal to 10(-8) m(2) s(-1), with a statistical distribution ranging from 10(-10) to 10(-7) m(2) s(-1), which is of the same order of magnitude as for the non-compressed cork. Then, oxygen transfer through cork compressed in a glass bottleneck was determined to assess the effect of the glass/cork interface. In the particular case of a gradient-imposed diffusion of oxygen through our model corked bottleneck system (dry cork without surface treatment; 200 and ∼0 hPa of oxygen on both sides of the sample), the mean effective diffusion coefficient is of 5 × 10(-7) m(2) s(-1), thus revealing the possible importance of the role of the glass/stopper interface in the oxygen transfer. PMID:27564243

  13. South West Georgia: an important bottleneck for raptor migration during autumn

    NARCIS (Netherlands)

    B. Verhelst; J. Jansen; W. Vansteelant

    2011-01-01

    Counts of migrating raptors at Batumi, Georgia, revealed the eastern Black Sea coast to form one of the most important bottlenecks for raptor migration during autumn in the Eurasian-African migration system. Totals for 10 species (European Honey-buzzard Pernis apivorus, Steppe Buzzard Buteo buteo vu

  14. Dispersal and colonisation of plants in lowland streams: success rates and bottlenecks

    DEFF Research Database (Denmark)

    Riis, Tenna

    2008-01-01

    by releasing plant shoots and subsequently re-collecting the retained shoots in the study reach. The main bottleneck for plant colonisation in macrophyte-rich lowland streams is the primary colonisation (development of attached roots in the sediment from vegetative propagules or seedlings) of retained shoots...

  15. Steiner tree heuristic in the Euclidean d-space using bottleneck distances

    DEFF Research Database (Denmark)

    Lorenzen, Stephan Sloth; Winter, Pawel

    2016-01-01

    in a greedy fashion to obtain a low cost tree spanning all terminals. The weakness of this approach is that obtained solutions are topologically related to minimum spanning trees. To avoid this and to obtain even better solutions, bottleneck distances are utilized to determine good subsets of terminals...

  16. Strategic behavior and social outcomes in a bottleneck queue: experimental evidence

    DEFF Research Database (Denmark)

    Breinbjerg, Jesper Breinbjerg; Sebald, Alexander Christopher; Østerdal, Lars Peter

    2016-01-01

    We theoretically and experimentally study the differential incentive effects of three well known queue disciplines in a strategic environment in which a bottleneck facility opens and impatient players decide when to arrive. For a class of three-player games, we derive equilibrium arrivals under...

  17. Avoiding the problem state bottleneck by strategic use of the environment

    NARCIS (Netherlands)

    Borst, Jelmer P.; Buwalda, Trudy A.; van Rijn, Hedderik; Taatgen, Niels A.

    2013-01-01

    We investigated whether environmental support can be used to circumvent the problem state bottleneck in human multitasking. Previously, it was shown that people can only maintain a single chunk of information in their problem state resource, the central part of working memory. Consequently, when the

  18. Bottleneck distances and Steiner trees in the Euclidean d-space

    DEFF Research Database (Denmark)

    Winter, Pawel; Lorenzen, Stephan Sloth

    fashion to obtain low cost trees spanning all terminals. The weakness of this approach is that obtained solutions are topologically related to minimum spanning trees. To obtain better solutions, bottleneck distances are utilized to determine good subsets of terminals without being constrained...

  19. The nocturnal bottleneck and the evolution of activity patterns in mammals

    NARCIS (Netherlands)

    Gerkema, Menno P.; Davies, Wayne I. L.; Foster, Russell G.; Menaker, Michael; Hut, Roelof A.

    2013-01-01

    In 1942, Walls described the concept of a 'nocturnal bottleneck' in placental mammals, where these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant taxon. Walls based this concept of a longer episode of nocturnality in early eutherian mammals

  20. Genetic variability and bottleneck detection of four Tricholoma matsutake populations from northeastern and southwestern China.

    Science.gov (United States)

    Zeng, Dong-Fang; Chen, Bin

    2015-08-01

    The excessive commercial collection of matsutake mushrooms can lead to extreme reduction of population size, which may cause genetic bottleneck and decrease genetic diversity of Tricholoma matsutake. Here, six polymorphic microsatellite loci markers were used to examine the genetic diversity of four natural T. matsutake populations from two main producing regions of China. The minimum combinations of four loci were able to discriminate total 86 sampled individuals with distinctive multilocus genotypes. Our analysis of molecular variance (AMOVA) revealed that about 80% and 20% of the overall genetic variation were respectively partitioned within and among populations. The principal-coordinate analyses (PCA) distinguished the four tested populations into three genetic clusters, each of which was correlated with respective endemic host plants on a geographical basis. The AMOVA, PCA and pairwise population FST estimates consistently displayed the same genetic divergence patterns and spatial structure of T. matsutake mediated by host plants in China. The significant heterozygosity excesses demonstrated that a recent genetic bottleneck occurred in each population tested. The complementary M-ratio test indicated past genetic bottleneck events over longer periods. Only four individuals were identified as putative first generation migrants within northeastern China, which implies restricted interpopulation gene flow in T. matsutake. We discuss that the significant genetic differentiation among populations of T. matsutake is most likely a function of host adaptation, host specificity, genetic bottleneck, limited dispersal and habitat fragmentation. PMID:25682708

  1. Achievements & bottlenecks in humanitarian demining EU-funded research: Final results from the EC DELVE project

    NARCIS (Netherlands)

    Sahli, H.; Bruschini, C.; Kempen, L. van; Schleijpen, H.M.A.; Breejen, E. den

    2008-01-01

    The EC DELVE Support Action project has analyzed the bottlenecks in the transfer of Humanitarian Demining (HD) technology from technology development to the use in the field, and drawn some lessons learned, basing itself on the assessment of the European Humanitarian Demining Research and Technology

  2. The strength and timing of the mitochondrial bottleneck in salmon suggests a conserved mechanism in vertebrates.

    Directory of Open Access Journals (Sweden)

    Jonci N Wolff

    Full Text Available In most species mitochondrial DNA (mtDNA is inherited maternally in an apparently clonal fashion, although how this is achieved remains uncertain. Population genetic studies show not only that individuals can harbor more than one type of mtDNA (heteroplasmy but that heteroplasmy is common and widespread across a diversity of taxa. Females harboring a mixture of mtDNAs may transmit varying proportions of each mtDNA type (haplotype to their offspring. However, mtDNA variants are also observed to segregate rapidly between generations despite the high mtDNA copy number in the oocyte, which suggests a genetic bottleneck acts during mtDNA transmission. Understanding the size and timing of this bottleneck is important for interpreting population genetic relationships and for predicting the inheritance of mtDNA based disease, but despite its importance the underlying mechanisms remain unclear. Empirical studies, restricted to mice, have shown that the mtDNA bottleneck could act either at embryogenesis, oogenesis or both. To investigate whether the size and timing of the mitochondrial bottleneck is conserved between distant vertebrates, we measured the genetic variance in mtDNA heteroplasmy at three developmental stages (female, ova and fry in chinook salmon and applied a new mathematical model to estimate the number of segregating units (N(e of the mitochondrial bottleneck between each stage. Using these data we estimate values for mtDNA Ne of 88.3 for oogenesis, and 80.3 for embryogenesis. Our results confirm the presence of a mitochondrial bottleneck in fish, and show that segregation of mtDNA variation is effectively complete by the end of oogenesis. Considering the extensive differences in reproductive physiology between fish and mammals, our results suggest the mechanism underlying the mtDNA bottleneck is conserved in these distant vertebrates both in terms of it magnitude and timing. This finding may lead to improvements in our understanding of

  3. More precisely biased : increasing the number of markers is not a silver bullet in genetic bottleneck testing

    NARCIS (Netherlands)

    Peery, M. Zachariah; Reid, Brendan N.; Kirby, Rebecca; Stoelting, Ricka; Doucet-Beer, Elena; Robinson, Stacie; Vasquez-Carrillo, Catalina; Pauli, Jonathan N.; Palsboll, Per J.

    2013-01-01

    In response to our review of the use of genetic bottleneck tests in the conservation literature (Peery etal. 2012, Molecular Ecology, 21, 3403-3418), Hoban etal. (2013, Molecular Ecology, in press) conducted population genetic simulations to show that the statistical power of genetic bottleneck test

  4. 基于瓶颈多态性的生产物流瓶颈闭环预测方法%Close-loop prediction method of logistics bottleneck based on bottleneck polymorphism

    Institute of Scientific and Technical Information of China (English)

    刘志; 唐娟; 费志敏

    2012-01-01

    针对不确定性环境下的生产物流瓶颈漂移预测问题,提出一种基于瓶颈多态性的瓶颈闭环预测方法。建立灵敏型瓶颈、迟钝型瓶颈、渐向型瓶颈和渐离型瓶颈的概念,以定性描述制造系统的物流瓶颈多态性;以瓶颈指数为基础,以制造单元时问和质量为参数,构建瓶颈漂移指数数学模型,并以此为依据构建瓶颈多态性判定机制,以实现瓶颈多态性的定量描述,进而为瓶颈漂移规律的研究提供技术支持;构建包含数据统计分析、瓶颈预测机制、瓶颈多态性分析和瓶颈指数迭代预测四项内容的瓶颈闭环预测方法,以实现生产物流瓶颈的动态连续预测。通过对某汽车装配车间生产物流瓶颈的动态预测和监控,验证了该方法的有效性和准确性。%Aiming at the prediction problem of production logistics bottleneck shifting under uncertain environment, a closed-loop prediction method of bottleneck was proposed based on bottleneck polymorphisrrL The concepts of sensi- tive bottleneck, obtuse bottleneck, growing bottleneck and decreasing bottleneck were formulated to describe the lo- gistics bottleneck polymorphism of manufacturing system qualitatively. Based on bottleneck index, mathematical model of bottleneck shifting index was established by taking time and quality of manufacturing unit as parameters. Decision mechanism of bottleneck polymorphism was constructed to realize bottleneck polymorphism description on the basis of bottleneck shifting index quantitatively, which provided technological support for studying on bottleneck shifting rule. The bottleneck closed-loop prediction method which was composed of data statistic analysis, bottle- neck prediction mechanism, bottleneck polymorphism analysis and bottleneck index iterative prediction was founded to realize dynamic and continuous prediction of production logistics bottleneck. An example of dynamically forecas- ting

  5. 基于两种瓶颈度的制造车间多瓶颈动态预测方法%Dynamic Prediction Method of Multi-bottleneck in Manufacturing Shop Based on Two Bottleneck Degrees

    Institute of Scientific and Technical Information of China (English)

    刘志; 蒋增强; 龚本刚

    2014-01-01

    针对制造车间多瓶颈预测问题,提出一种基于两种瓶颈度的多瓶颈动态预测方法,以在合理认定瓶颈责任的前提下实现系统多瓶颈的连续准确预测。首先,建立综合瓶颈度和独立瓶颈度的概念模型,并以时间、质量和成本为参数,构建其数学模型;然后,构建包含多瓶颈双层预测机制、瓶颈多态性分析和瓶颈指数迭代预测模型的多瓶颈动态预测方法;最后,将多瓶颈动态预测方法、单瓶颈度法和PBM 法运用至某汽车产品总装线,以验证该方法有效性。%Aiming at the prediction problem of multi-bottleneck in complex manufacturing shop , a dynamic prediction method of multi-bottleneck was proposed based on two bottleneck degrees ,which can forecast bottleneck accurately under conditions that bottleneck responsibility was verified reasona-bly .Firstly ,conceptual models about general bottleneck degree and independent bottleneck degree were built ,and then taking time ,quality and cost as parameters ,their mathematical models were es-tablished .Secondly ,one dynamic prediction method of multi-bottleneck was come up with ,which con-tained dual-layer multi-bottleneck prediction mechanism ,bottleneck polymorphism analysis and the it-erative prediction of bottleneck index .Finally ,it is proved to be superior and credible by comparison to the method of single bottleneck degree and the method of PBM for production bottleneck prediction problem of one vehicle assembly line .

  6. Zero-temperature quantum annealing bottlenecks in the spin-glass phase

    Science.gov (United States)

    Knysh, Sergey

    2016-08-01

    A promising approach to solving hard binary optimization problems is quantum adiabatic annealing in a transverse magnetic field. An instantaneous ground state--initially a symmetric superposition of all possible assignments of N qubits--is closely tracked as it becomes more and more localized near the global minimum of the classical energy. Regions where the energy gap to excited states is small (for instance at the phase transition) are the algorithm's bottlenecks. Here I show how for large problems the complexity becomes dominated by O(log N) bottlenecks inside the spin-glass phase, where the gap scales as a stretched exponential. For smaller N, only the gap at the critical point is relevant, where it scales polynomially, as long as the phase transition is second order. This phenomenon is demonstrated rigorously for the two-pattern Gaussian Hopfield model. Qualitative comparison with the Sherrington-Kirkpatrick model leads to similar conclusions.

  7. Note: Inhibiting bottleneck corrosion in electrical calcium tests for ultra-barrier measurements

    Science.gov (United States)

    Nehm, F.; Müller-Meskamp, L.; Klumbies, H.; Leo, K.

    2015-12-01

    A major failure mechanism is identified in electrical calcium corrosion tests for quality assessment of high-end application moisture barriers. Accelerated calcium corrosion is found at the calcium/electrode junction, leading to an electrical bottleneck. This causes test failure not related to overall calcium loss. The likely cause is a difference in electrochemical potential between the aluminum electrodes and the calcium sensor, resulting in a corrosion element. As a solution, a thin, full-area copper layer is introduced below the calcium, shifting the corrosion element to the calcium/copper junction and inhibiting bottleneck degradation. Using the copper layer improves the level of sensitivity for the water vapor transmission rate (WVTR) by over one order of magnitude. Thin-film encapsulated samples with 20 nm of atomic layer deposited alumina barriers this way exhibit WVTRs of 6 × 10-5 g(H2O)/m2/d at 38 °C, 90% relative humidity.

  8. Squeezing through the Now-or-Never bottleneck: Reconnecting language processing, acquisition, change, and structure.

    Science.gov (United States)

    Chater, Nick; Christiansen, Morten H

    2016-01-01

    If human language must be squeezed through a narrow cognitive bottleneck, what are the implications for language processing, acquisition, change, and structure? In our target article, we suggested that the implications are far-reaching and form the basis of an integrated account of many apparently unconnected aspects of language and language processing, as well as suggesting revision of many existing theoretical accounts. With some exceptions, commentators were generally supportive both of the existence of the bottleneck and its potential implications. Many commentators suggested additional theoretical and linguistic nuances and extensions, links with prior work, and relevant computational and neuroscientific considerations; some argued for related but distinct viewpoints; a few, though, felt traditional perspectives were being abandoned too readily. Our response attempts to build on the many suggestions raised by the commentators and to engage constructively with challenges to our approach.

  9. Understanding of empty container movement: A study on a bottleneck at an off-dock depot

    Science.gov (United States)

    Zain, Rosmaizura Mohd; Rahman, Mohd Nizam Ab; Nopiah, Zulkifli Mohd; Saibani, Nizaroyani

    2014-09-01

    Port not only function as connections between marine and land transportation but also as core business areas. In a port terminal, available space is limited, but the influx of container is growing. The off-dock depot is one of the key supply chain players that hold empty containers in the inventory. Therefore, this paper aims to identify the main factors of bottlenecks or congestion that hinder the rapid movement of empty containers from the off-dock depot to the customers. Thirty interviews were conducted with individuals who are key players in the container supply chain. The data were analyzed using Atlas.ti software and the analytic hierarchy process to rank the priority factors of bottlenecks. Findings show that several pertinent factors act as barriers to the key players in the container movement in the day-to-day operations. In future studies, strategies to overcome fragmentation in the container supply chain and logistics must be determined.

  10. CO2 capture enhancement in InOF-1 via the bottleneck effect of confined ethanol.

    Science.gov (United States)

    Peralta, Ricardo A; Campos-Reales-Pineda, Alberto; Pfeiffer, Heriberto; Álvarez, J Raziel; Zárate, J Antonio; Balmaseda, Jorge; González-Zamora, Eduardo; Martínez, Ana; Martínez-Otero, Diego; Jancik, Vojtech; Ibarra, Ilich A

    2016-08-11

    CO2 capture of InOF-1 was enhanced 3.6-fold, at 1 bar and 30 °C, by confining EtOH within its pores. Direct visualisation by single crystal X-ray diffraction revealed that EtOH divides InOF-1 channels in wide sections separated by "bottlenecks" caused by EtOH molecules bonded to the μ2-OH functional groups of InOF-1. PMID:27469274

  11. Why don’t we see changes?: The role of attentional bottlenecks and limited visual memory

    OpenAIRE

    Jeremy M Wolfe; Reinecke, Andrea; BRAWN, PETER

    2006-01-01

    Seven experiments explore the role of bottlenecks in selective attention and access to visual short-term memory in the failure of observers to identify clearly visible changes in otherwise stable visual displays. Experiment One shows that observers fail to register a color change in an object even if they are cued to the location of the object by a transient at that location as the change is occurring. Experiment Two shows the same for orientation change. In Experiments Three and Four, attent...

  12. An assessment of The Capacity Drops at The Bottleneck Segments: A review on the existing methodologies

    Directory of Open Access Journals (Sweden)

    Sugiarto Sugiarto

    2015-08-01

    Full Text Available The term of capacity is very useful to quantify the ability of transport facilities in terms of carrying traffic. The capacity of the road is an essential ingredient in the planning, design, and operation of roadways. It is desirable for traffic analyst to be able to predict the time and places where congestion will occur and the volumes to be expected. Most of urbanized areas have been experiencing of traffic congestion problems particularly at urban arterial systems. High traffic demand and limited supply of roadways are always the main factors produced traffic congestion. However, there are other sources of local and temporal congestion, such as uncontrolled access point, median opening and on-street parking activities, which are caused a reduction of roadway capacity during peak operations. Those locations could result in reduction of travel speed and road, as known as hidden bottlenecks. This is bottleneck which is without any changes in geometric of the segments. The Indonesian Highway Capacity Manual (IHCM, 1997 is used to assess urban arterial systems till current days. IHCM provides a static method for examining the capacityand does not systematically take into account of bottleneck activities. However, bottleneck activities create interruption smooth traffic flow along arterial streets, which in turns stimulate related problems, such as, excessive air pollution, additional energy consumption and driver’s frustration due to traffic jammed. This condition could happen simultaneously; mostly repetitive and predictable in same peak hour demands. Therefore, this paper carefully summarize on the existing methodologies considering required data, handled data processing and expected output of each proposed of analysis. We further notice that dynamic approach could be more appropriated for analyzing temporal congestion segments (median opening, on street parking, etc.. Method of oblique cumulative plot seems to be more applicable in terms of

  13. Bottleneck of Farmers’ Quality in New Socialist Countryside Construction and Countermeasures

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    We analyzed problems of farmers’ quality in the new socialist countryside construction,including low educational level,poor specialized skills,and low ideological and ethical quality.These problems become bottleneck of the socialist countryside construction.In view of these problems,we put forward following countermeasures:speeding up urbanization development,consolidating rural basic education,strengthening rural vocational education,and developing new approaches to improve farmers’ ideological and ethical quality.

  14. Emerging from the bottleneck: Benefits of the comparative approach to modern neuroscience

    OpenAIRE

    Brenowitz, Eliot A.; Zakon, Harold H.

    2015-01-01

    Neuroscience historically exploited a wide diversity of animal taxa. Recently, however, research focused increasingly on a few model species. This trend accelerated with the genetic revolution, as genomic sequences and genetic tools became available for a few species, which formed a bottleneck. This coalescence on a small set of model species comes with several costs often not considered, especially in the current drive to use mice explicitly as models for human diseases. Comparative studies ...

  15. On the prospect of identifying adaptive loci in recently bottlenecked populations.

    Directory of Open Access Journals (Sweden)

    Yu-Ping Poh

    Full Text Available Identifying adaptively important loci in recently bottlenecked populations - be it natural selection acting on a population following the colonization of novel habitats in the wild, or artificial selection during the domestication of a breed - remains a major challenge. Here we report the results of a simulation study examining the performance of available population-genetic tools for identifying genomic regions under selection. To illustrate our findings, we examined the interplay between selection and demography in two species of Peromyscus mice, for which we have independent evidence of selection acting on phenotype as well as functional evidence identifying the underlying genotype. With this unusual information, we tested whether population-genetic-based approaches could have been utilized to identify the adaptive locus. Contrary to published claims, we conclude that the use of the background site frequency spectrum as a null model is largely ineffective in bottlenecked populations. Results are quantified both for site frequency spectrum and linkage disequilibrium-based predictions, and are found to hold true across a large parameter space that encompasses many species and populations currently under study. These results suggest that the genomic footprint left by selection on both new and standing variation in strongly bottlenecked populations will be difficult, if not impossible, to find using current approaches.

  16. Sequential bottlenecks drive viral evolution in early acute hepatitis C virus infection.

    Directory of Open Access Journals (Sweden)

    Rowena A Bull

    2011-09-01

    Full Text Available Hepatitis C is a pandemic human RNA virus, which commonly causes chronic infection and liver disease. The characterization of viral populations that successfully initiate infection, and also those that drive progression to chronicity is instrumental for understanding pathogenesis and vaccine design. A comprehensive and longitudinal analysis of the viral population was conducted in four subjects followed from very early acute infection to resolution of disease outcome. By means of next generation sequencing (NGS and standard cloning/Sanger sequencing, genetic diversity and viral variants were quantified over the course of the infection at frequencies as low as 0.1%. Phylogenetic analysis of reassembled viral variants revealed acute infection was dominated by two sequential bottleneck events, irrespective of subsequent chronicity or clearance. The first bottleneck was associated with transmission, with one to two viral variants successfully establishing infection. The second occurred approximately 100 days post-infection, and was characterized by a decline in viral diversity. In the two subjects who developed chronic infection, this second bottleneck was followed by the emergence of a new viral population, which evolved from the founder variants via a selective sweep with fixation in a small number of mutated sites. The diversity at sites with non-synonymous mutation was higher in predicted cytotoxic T cell epitopes, suggesting immune-driven evolution. These results provide the first detailed analysis of early within-host evolution of HCV, indicating strong selective forces limit viral evolution in the acute phase of infection.

  17. The nocturnal bottleneck and the evolution of activity patterns in mammals.

    Science.gov (United States)

    Gerkema, Menno P; Davies, Wayne I L; Foster, Russell G; Menaker, Michael; Hut, Roelof A

    2013-08-22

    In 1942, Walls described the concept of a 'nocturnal bottleneck' in placental mammals, where these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant taxon. Walls based this concept of a longer episode of nocturnality in early eutherian mammals by comparing the visual systems of reptiles, birds and all three extant taxa of the mammalian lineage, namely the monotremes, marsupials (now included in the metatherians) and placentals (included in the eutherians). This review describes the status of what has become known as the nocturnal bottleneck hypothesis, giving an overview of the chronobiological patterns of activity. We review the ecological plausibility that the activity patterns of (early) eutherian mammals were restricted to the night, based on arguments relating to endothermia, energy balance, foraging and predation, taking into account recent palaeontological information. We also assess genes, relating to light detection (visual and non-visual systems) and the photolyase DNA protection system that were lost in the eutherian mammalian lineage. Our conclusion presently is that arguments in favour of the nocturnal bottleneck hypothesis in eutherians prevail.

  18. Incident and Traffic-Bottleneck Detection Algorithm in High-Resolution Remote Sensing Imagery

    Directory of Open Access Journals (Sweden)

    S.M.M. Kahaki

    2012-09-01

    Full Text Available One of the most important methods to solve traffic congestion is to detect the incident state of a roadway. This paper describes the development of a method for road traffic monitoring aimed at the acquisition and analysis of remote sensing imagery. We propose a strategy for road extraction, vehicle detection and incident detection from remote sensing imagery using techniques based on neural networks, Radon transform for angle detection and traffic-flow measurements. Traffic-bottleneck detection is another method that is proposed for recognizing incidents in both offline and real-time mode. Traffic flows and incidents are extracted from aerial images of bottleneck zones. The results show that the proposed approach has a reasonable detection performance compared to other methods. The best performance of the learning system was a detection rate of 87% and a false alarm rate of less than 18% on 45 aerial images of roadways. The performance of the traffic-bottleneck detection method had a detection rate of 87.5%.

  19. Managing bottlenecks in manual automobile assembly systems using discrete event simulation

    Directory of Open Access Journals (Sweden)

    Dewa, M.

    2013-08-01

    Full Text Available Batch model lines are quite handy when the demand for each product is moderate. However, they are characterised by high work-in-progress inventories, lost production time when changing over models, and reduced flexibility when it comes to altering production rates as product demand changes. On the other hand, mixed model lines can offer reduced work-in-progress inventory and increased flexibility. The object of this paper is to illustrate that a manual automobile assembling system can be optimised through managing bottlenecks by ensuring high workstation utilisation, reducing queue lengths before stations and reducing station downtime. A case study from the automobile industry is used for data collection. A model is developed through the use of simulation software. The model is then verified and validated before a detailed bottleneck analysis is conducted. An operational strategy is then proposed for optimal bottleneck management. Although the paper focuses on improving automobile assembly systems in batch mode, the methodology can also be applied in single model manual and automated production lines.

  20. Potential and bottlenecks of the carbon market: The case of a developing country, Nepal

    International Nuclear Information System (INIS)

    The majority of clean development mechanism (CDM) projects are confined to a few countries. For many developing nations, entry into the carbon market, either through CDM or others, has been difficult. Thus, rationalizing CDM projects and the carbon market as a tool for sustainable development is often questioned. Many developing countries, such as Nepal, lack a quantification of CO2 reduction potential and an assessment of bottlenecks necessary for the carbon market. In this context, this paper assesses the potential emission reductions from major sectors of Nepal and the accompanying bottlenecks of the carbon market. The analyses provide indications of the type and scale of the carbon mitigation opportunities in key sectors such as waste management, biogas utilization, promotion of electric vehicles, rice cultivation, bio-energy utilization, brick making, hydropower development and a few others. These might be helpful to decision-makers in Nepal as well as to the process of re-orienting CDM and other carbon markets to better understand the bottlenecks of developing countries.

  1. Mine production index (MPI)-extension of OEE for bottleneck detection in mining

    Institute of Scientific and Technical Information of China (English)

    Amol Arun Lanke; Seyed Hadi Hoseinie; Behzad Ghodrati

    2016-01-01

    Although mining production depends on various equipments, significant amount of production loss can be attributed a specific equipment or fleet. Bottleneck is defined not only by production loss but also by our satisfaction from the equipment. The user satisfaction could be measured as machine effectiveness. Mining literatures on performance improvement and optimization of equipment operations assert importance of availability, utilization and production performance as key parameters. These three param-eters are useful for evaluating effectiveness of equipment. Mine production index (MPI), which can rep-resent the effect of these factors, has been applied for continuous operation in mining. MPI uses Fuzzy Delphi Analytical Hierarchy Process to determine importance of each three parameter for individual equipment. A case study in a Swedish open pit mine was done to evaluate the field application of MPI. The results reveal that crusher is the bottleneck equipment in studied mine. As a methodical approach, an algorithm which uses MPI and detects bottleneck in continuous mining operation has been proposed.

  2. Lagrangian-averaged model for magnetohydrodynamic turbulence and the absence of bottlenecks.

    Science.gov (United States)

    Pietarila Graham, Jonathan; Mininni, Pablo D; Pouquet, Annick

    2009-07-01

    We demonstrate that, for the case of quasiequipartition between the velocity and the magnetic field, the Lagrangian-averaged magnetohydrodynamics (LAMHD) alpha model reproduces well both the large-scale and the small-scale properties of turbulent flows; in particular, it displays no increased (superfilter) bottleneck effect with its ensuing enhanced energy spectrum at the onset of the subfilter scales. This is in contrast to the case of the neutral fluid in which the Lagrangian-averaged Navier-Stokes alpha model is somewhat limited in its applications because of the formation of spatial regions with no internal degrees of freedom and subsequent contamination of superfilter-scale spectral properties. We argue that, as the Lorentz force breaks the conservation of circulation and enables spectrally nonlocal energy transfer (associated with Alfvén waves), it is responsible for the absence of a viscous bottleneck in magnetohydrodynamics (MHD), as compared to the fluid case. As LAMHD preserves Alfvén waves and the circulation properties of MHD, there is also no (superfilter) bottleneck found in LAMHD, making this method capable of large reductions in required numerical degrees of freedom; specifically, we find a reduction factor of approximately 200 when compared to a direct numerical simulation on a large grid of 1536;{3} points at the same Reynolds number. PMID:19658812

  3. Circulating virus load determines the size of bottlenecks in viral populations progressing within a host.

    Directory of Open Access Journals (Sweden)

    Serafín Gutiérrez

    Full Text Available For any organism, population size, and fluctuations thereof, are of primary importance in determining the forces driving its evolution. This is particularly true for viruses--rapidly evolving entities that form populations with transient and explosive expansions alternating with phases of migration, resulting in strong population bottlenecks and associated founder effects that increase genetic drift. A typical illustration of this pattern is the progression of viral disease within a eukaryotic host, where such demographic fluctuations are a key factor in the emergence of new variants with altered virulence. Viruses initiate replication in one or only a few infection foci, then move through the vasculature to seed secondary infection sites and so invade distant organs and tissues. Founder effects during this within-host colonization might depend on the concentration of infectious units accumulating and circulating in the vasculature, as this represents the infection dose reaching new organs or "territories". Surprisingly, whether or not the easily measurable circulating (plasma virus load directly drives the size of population bottlenecks during host colonization has not been documented in animal viruses, while in plants the virus load within the sap has never been estimated. Here, we address this important question by monitoring both the virus concentration flowing in host plant sap, and the number of viral genomes founding the population in each successive new leaf. Our results clearly indicate that the concentration of circulating viruses directly determines the size of bottlenecks, which hence controls founder effects and effective population size during disease progression within a host.

  4. Modeling the Impact of Border Crossing Bottlenecks on Supply Chain Disruption Risk

    Directory of Open Access Journals (Sweden)

    Shaheen Sardar

    2015-04-01

    Full Text Available In order to remain competitive, companies outsource the manufacturing process to global markets. Globalization requires shipping of goods across borders. Cross border movement of goods faces diverse difficulties and creates bottlenecks in the supply chain. Complex products involve numerous parts and complications in the assembly process, resulting in multiple border-crossings with varying level of complexity across multiple countries before reaching to the customers. This activity contributes to the supply chain disruption risk. Border crossing is unavoidable in global supply chains, and how to integrate border crossing complexity in supply chain models is an unresolved issue. This paper suggests an approach to quantify the border crossing complexity and its impact on the supply chain disruption risk in the global outsourcing environment. Results show that key factors which contribute to border crossing complexity include product complexity, trade procedures, and various bottlenecks at each bordercrossing. Based on results drawn from the quantitative analysis, we propose several strategies to manage the impact of border crossing bottlenecks. The focus of this research is the manufacturing companies which are involved in managing the global supply chains.

  5. BOTTLENECK ANALYSIS AND STRATEGIC PLANNING ON CHILDHOOD DIARRHEA MANAGEMENT IN 6 HIGH PRIORITY DISTRICTS OF GUJARAT

    Directory of Open Access Journals (Sweden)

    Rupani Mihir

    2015-01-01

    Full Text Available Introduction:Bottleneck Analysis and Strategic Planning exercise was carried out in 6 High Priority Districts (HPDs, under Call-to-Action for RMNCH+A strategy.Rationale: In spite of continued efforts, India is still lagging behind in its MDG goals.Objectives: To identify gaps in childhood diarrhea management and propose strategic options for the same.Materials and Methods: Bottleneck analysis exercisewas carried out based on the Tanahashi model, desk review and focused group discussions between district officials, front-line workers and UNICEF officials. These bottlenecks were pertaining to the availability, accessibility, utilization of services and quality of services being provided by the health department.Elaborating the Tanahashi model for the 6 HPDs, 94% of the front-line workers (FLWs had stock of Zinc-ORS; 88% FLWs were trained in diarrhea management; 98% villages had at least one FLW trained in diarrhea management; health care seeking for diarrhea cases was 17%; 5.1% diarrhea cases received Zinc-ORS from health worker and 2.4% care takers prepared Zinc-ORS in safe drinking water.Results: The major bottlenecks identified for Childhood Diarrhea management in the 6 High Priority Districts were poor demand generation, unsafe drinking water, poor access to improved sanitation facility and lack of equitable distribution of Zinc-ORS till the front-line worker level. The main strategic options that were suggested for relieving these bottlenecks were Zinc-ORS roll out in scale-up districts, develop IEC/BCC plan for childhood diarrhea management at state/district level, use of Drug Logistics Information Management System (DLIMS software for supply chain management of Zinc-ORS, strengthening of chlorination activity at household level, monitoring implementation of Nirmal Bharat Abhiyaan (NBA for constructing improved sanitation facilities at household level and to develop an IEC/BCC plan for hygiene promotion and usage of sanitary latrines

  6. Bottleneck Prediction Method Based on Improved Adaptive Network-based Fuzzy Inference System (ANFIS) in Semiconductor Manufacturing System%Bottleneck Prediction Method Based on Improved Adaptive Network-based Fuzzy Inference System (ANFIS) in Semiconductor Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    曹政才; 邓积杰; 刘民; 王永吉

    2012-01-01

    Semiconductor manufacturing (SM) system is one of the most complicated hybrid processes involved continuously variable dynamical systems and discrete event dynamical systems. The optimization and scheduling of semiconductor fabrication has long been a hot research direction in automation. Bottleneck is the key factor to a SM system, which seriously influences the throughput rate, cycle time, time-delivery rate, etc. Efficient prediction for the bottleneck of a SM system provides the best support for the consequent scheduling. Because categorical data (product types, releasing strategies) and numerical data (work in process, processing time, utilization rate, buffer length, etc.) have significant effect on bottleneck, an improved adaptive network-based fuzzy inference system (ANFIS) was adopted in this study to predict bottleneck since conventional neural network-based methods accommodate only numerical inputs. In this improved ANFIS, the contribution of categorical inputs to firing strength is reflected through a transformation matrix. In order to tackle high-dimensional inputs, reduce the number of fuzzy rules and obtain high prediction accuracy, a fuzzy c-means method combining binary tree linear division method was applied to identify the initial structure of fuzzy inference system. According to the experimental results, the main-bottleneck and sub-bottleneck of SM system can be predicted accurately with the proposed method.

  7. Anatomy of a bottleneck: diagnosing factors limiting population growth in the Puerto Rican parrot

    Science.gov (United States)

    Beissenger, S.R.; Wunderle, J.M.; Meyers, J.M.; Saether, B.-E.; Engen, S.

    2008-01-01

    The relative importance of genetic, demographic, environmental, and catastrophic processes that maintain population bottlenecks has received little consideration. We evaluate the role of these factors in maintaining the Puerto Rican Parrot (Amazona vittata) in a prolonged bottleneck from 1973 through 2000 despite intensive conservation efforts. We first conduct a risk analysis, then examine evidence for the importance of specific processes maintaining the bottleneck using the multiple competing hypotheses approach, and finally integrate these results through a sensitivity analysis of a demographic model using life-stage simulation analysis (LSA) to determine the relative importance of genetic, demographic, environmental, and catastrophic processes on population growth. Annual population growth has been slow and variable (1.0 6 5.2 parrots per year, or an average k?1.05 6 0.19) from 16 parrots (1973) to a high of 40-42 birds (1997-1998). A risk analysis based on population prediction intervals (PPI) indicates great risk and large uncertainty, with a range of 22?83 birds in the 90% PPI only five years into the future. Four primary factors (reduced hatching success due to inbreeding, failure of adults to nest, nest failure due to nongenetic causes, and reduced survival of adults and juveniles) were responsible for maintaining the bottleneck. Egghatchability rates were low (70.6% per egg and 76.8% per pair), and hatchability increased after mate changes, suggesting inbreeding effects. Only an average of 34% of the population nested annually, which was well below the percentage of adults that should have reached an age of first breeding (41-56%). This chronic failure to nest appears to have been caused primarily by environmental and/or behavioral factors, and not by nest-site scarcity or a skewed sex ratio. Nest failure rates from nongenetic causes (i.e., predation, parasitism, and wet cavities) were low (29%) due to active management (protecting nests and fostering

  8. High and distinct range-edge genetic diversity despite local bottlenecks.

    Science.gov (United States)

    Assis, Jorge; Castilho Coelho, Nelson; Alberto, Filipe; Valero, Myriam; Raimondi, Pete; Reed, Dan; Serrão, Ester Alvares

    2013-01-01

    The genetic consequences of living on the edge of distributional ranges have been the subject of a largely unresolved debate. Populations occurring along persistent low latitude ranges (rear-edge) are expected to retain high and unique genetic diversity. In contrast, currently less favourable environmental conditions limiting population size at such range-edges may have caused genetic erosion that prevails over past historical effects, with potential consequences on reducing future adaptive capacity. The present study provides an empirical test of whether population declines towards a peripheral range might be reflected on decreasing diversity and increasing population isolation and differentiation. We compare population genetic differentiation and diversity with trends in abundance along a latitudinal gradient towards the peripheral distribution range of Saccorhiza polyschides, a large brown seaweed that is the main structural species of kelp forests in SW Europe. Signatures of recent bottleneck events were also evaluated to determine whether the recently recorded distributional shifts had a negative influence on effective population size. Our findings show decreasing population density and increasing spatial fragmentation and local extinctions towards the southern edge. Genetic data revealed two well supported groups with a central contact zone. As predicted, higher differentiation and signs of bottlenecks were found at the southern edge region. However, a decrease in genetic diversity associated with this pattern was not verified. Surprisingly, genetic diversity increased towards the edge despite bottlenecks and much lower densities, suggesting that extinctions and recolonizations have not strongly reduced diversity or that diversity might have been even higher there in the past, a process of shifting genetic baselines. PMID:23967038

  9. Laboratory colonisation and genetic bottlenecks in the tsetse fly Glossina pallidipes.

    Directory of Open Access Journals (Sweden)

    Marc Ciosi

    2014-02-01

    Full Text Available BACKGROUND: The IAEA colony is the only one available for mass rearing of Glossina pallidipes, a vector of human and animal African trypanosomiasis in eastern Africa. This colony is the source for Sterile Insect Technique (SIT programs in East Africa. The source population of this colony is unclear and its genetic diversity has not previously been evaluated and compared to field populations. METHODOLOGY/PRINCIPAL FINDINGS: We examined the genetic variation within and between the IAEA colony and its potential source populations in north Zimbabwe and the Kenya/Uganda border at 9 microsatellites loci to retrace the demographic history of the IAEA colony. We performed classical population genetics analyses and also combined historical and genetic data in a quantitative analysis using Approximate Bayesian Computation (ABC. There is no evidence of introgression from the north Zimbabwean population into the IAEA colony. Moreover, the ABC analyses revealed that the foundation and establishment of the colony was associated with a genetic bottleneck that has resulted in a loss of 35.7% of alleles and 54% of expected heterozygosity compared to its source population. Also, we show that tsetse control carried out in the 1990's is likely reduced the effective population size of the Kenya/Uganda border population. CONCLUSIONS/SIGNIFICANCE: All the analyses indicate that the area of origin of the IAEA colony is the Kenya/Uganda border and that a genetic bottleneck was associated with the foundation and establishment of the colony. Genetic diversity associated with traits that are important for SIT may potentially have been lost during this genetic bottleneck which could lead to a suboptimal competitiveness of the colony males in the field. The genetic diversity of the colony is lower than that of field populations and so, studies using colony flies should be interpreted with caution when drawing general conclusions about G. pallidipes biology.

  10. Mitochondrial DNA sequence characteristics modulate the size of the genetic bottleneck.

    Science.gov (United States)

    Wilson, Ian J; Carling, Phillipa J; Alston, Charlotte L; Floros, Vasileios I; Pyle, Angela; Hudson, Gavin; Sallevelt, Suzanne C E H; Lamperti, Costanza; Carelli, Valerio; Bindoff, Laurence A; Samuels, David C; Wonnapinij, Passorn; Zeviani, Massimo; Taylor, Robert W; Smeets, Hubert J M; Horvath, Rita; Chinnery, Patrick F

    2016-03-01

    With a combined carrier frequency of 1:200, heteroplasmic mitochondrial DNA (mtDNA) mutations cause human disease in ∼1:5000 of the population. Rapid shifts in the level of heteroplasmy seen within a single generation contribute to the wide range in the severity of clinical phenotypes seen in families transmitting mtDNA disease, consistent with a genetic bottleneck during transmission. Although preliminary evidence from human pedigrees points towards a random drift process underlying the shifting heteroplasmy, some reports describe differences in segregation pattern between different mtDNA mutations. However, based on limited observations and with no direct comparisons, it is not clear whether these observations simply reflect pedigree ascertainment and publication bias. To address this issue, we studied 577 mother-child pairs transmitting the m.11778G>A, m.3460G>A, m.8344A>G, m.8993T>G/C and m.3243A>G mtDNA mutations. Our analysis controlled for inter-assay differences, inter-laboratory variation and ascertainment bias. We found no evidence of selection during transmission but show that different mtDNA mutations segregate at different rates in human pedigrees. m.8993T>G/C segregated significantly faster than m.11778G>A, m.8344A>G and m.3243A>G, consistent with a tighter mtDNA genetic bottleneck in m.8993T>G/C pedigrees. Our observations support the existence of different genetic bottlenecks primarily determined by the underlying mtDNA mutation, explaining the different inheritance patterns observed in human pedigrees transmitting pathogenic mtDNA mutations. PMID:26740552

  11. Bottleneck analysis and strategic planning using Tanahashi model for childhood diarrhea management in Gujarat, Western India.

    Science.gov (United States)

    Rupani, Mihir Prafulbhai; Gaonkar, Narayan T; Bhatt, Gneyaa S

    2016-10-01

    In spite of continued efforts, India is still lagging behind in achieving its MDG goals. The objectives of this study were to identify stake-holders who have a role to play in childhood diarrhea management, to identify gaps in childhood diarrhea management and to propose strategic options for relieving these gaps. Bottleneck analysis exercise was carried out based on the Tanahashi model in six High Priority Districts (HPDs) of Gujarat in period between July-November 2013. The major bottlenecks identified for Childhood Diarrhea management were poor demand generation, unsafe drinking water, poor access to improved sanitation facility and lack of equitable distribution and replenishment mechanisms for Oral Rehydration Solution (ORS) packets and Zinc tablets till the front-line worker level. The main strategic options that were suggested for relieving these bottlenecks were Zinc-ORS roll out in scale-up districts, develop Information Education Communication/Behaviour Change Communication (IEC/BCC) plan for childhood diarrhea management at state/district level, use of Drug Logistics Information Management System (DLIMS) software for supply chain management of Zinc-ORS, strengthening of chlorination activity at household level, monitoring implementation of Nirmal Bharat Abhiyaan (NBA) for constructing improved sanitation facilities at household level and to develop an IEC/BCC plan for hygiene promotion and usage of sanitary latrines. Use of Zinc tablets need to be intensified through an effective scale-up. Adequate demand generation activity is needed. There is need to address safe drinking water and improved sanitation measures at household levels. Multi-sectoral engagements and ownership of Zinc-ORS program is the need of the hour.

  12. High and distinct range-edge genetic diversity despite local bottlenecks.

    Directory of Open Access Journals (Sweden)

    Jorge Assis

    Full Text Available The genetic consequences of living on the edge of distributional ranges have been the subject of a largely unresolved debate. Populations occurring along persistent low latitude ranges (rear-edge are expected to retain high and unique genetic diversity. In contrast, currently less favourable environmental conditions limiting population size at such range-edges may have caused genetic erosion that prevails over past historical effects, with potential consequences on reducing future adaptive capacity. The present study provides an empirical test of whether population declines towards a peripheral range might be reflected on decreasing diversity and increasing population isolation and differentiation. We compare population genetic differentiation and diversity with trends in abundance along a latitudinal gradient towards the peripheral distribution range of Saccorhiza polyschides, a large brown seaweed that is the main structural species of kelp forests in SW Europe. Signatures of recent bottleneck events were also evaluated to determine whether the recently recorded distributional shifts had a negative influence on effective population size. Our findings show decreasing population density and increasing spatial fragmentation and local extinctions towards the southern edge. Genetic data revealed two well supported groups with a central contact zone. As predicted, higher differentiation and signs of bottlenecks were found at the southern edge region. However, a decrease in genetic diversity associated with this pattern was not verified. Surprisingly, genetic diversity increased towards the edge despite bottlenecks and much lower densities, suggesting that extinctions and recolonizations have not strongly reduced diversity or that diversity might have been even higher there in the past, a process of shifting genetic baselines.

  13. Bottleneck analysis and strategic planning using Tanahashi model for childhood diarrhea management in Gujarat, Western India.

    Science.gov (United States)

    Rupani, Mihir Prafulbhai; Gaonkar, Narayan T; Bhatt, Gneyaa S

    2016-10-01

    In spite of continued efforts, India is still lagging behind in achieving its MDG goals. The objectives of this study were to identify stake-holders who have a role to play in childhood diarrhea management, to identify gaps in childhood diarrhea management and to propose strategic options for relieving these gaps. Bottleneck analysis exercise was carried out based on the Tanahashi model in six High Priority Districts (HPDs) of Gujarat in period between July-November 2013. The major bottlenecks identified for Childhood Diarrhea management were poor demand generation, unsafe drinking water, poor access to improved sanitation facility and lack of equitable distribution and replenishment mechanisms for Oral Rehydration Solution (ORS) packets and Zinc tablets till the front-line worker level. The main strategic options that were suggested for relieving these bottlenecks were Zinc-ORS roll out in scale-up districts, develop Information Education Communication/Behaviour Change Communication (IEC/BCC) plan for childhood diarrhea management at state/district level, use of Drug Logistics Information Management System (DLIMS) software for supply chain management of Zinc-ORS, strengthening of chlorination activity at household level, monitoring implementation of Nirmal Bharat Abhiyaan (NBA) for constructing improved sanitation facilities at household level and to develop an IEC/BCC plan for hygiene promotion and usage of sanitary latrines. Use of Zinc tablets need to be intensified through an effective scale-up. Adequate demand generation activity is needed. There is need to address safe drinking water and improved sanitation measures at household levels. Multi-sectoral engagements and ownership of Zinc-ORS program is the need of the hour. PMID:27340871

  14. Phonon bottleneck in GaAs/AlxGa1−xAs quantum dots

    Directory of Open Access Journals (Sweden)

    Y. C. Chang

    2015-06-01

    Full Text Available We report low-temperature photoluminescence measurements on highly-uniform GaAs/AlxGa1−xAs quantum dots grown by droplet epitaxy. Recombination between confined electrons and holes bound to carbon acceptors in the dots allow us to determine the energies of the confined states in the system, as confirmed by effective mass calculations. The presence of acceptor-bound holes in the quantum dots gives rise to a striking observation of the phonon-bottleneck effect.

  15. Direct structural mapping of organic field-effect transistors reveals bottlenecks to carrier transport

    KAUST Repository

    Li, Ruipeng

    2012-08-10

    X-ray microbeam scattering is used to map the microstructure of the organic semiconductor along the channel length of solution-processed bottom-contact OFET devices. Contact-induced nucleation is known to influence the crystallization behavior within the channel. We find that microstructural inhomogeneities in the center of the channel act as a bottleneck to charge transport. This problem can be overcome by controlling crystallization of the preferable texture, thus favoring more efficient charge transport throughout the channel. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Breaking CFD Bottlenecks in Gas-Turbine Flow-Path Design

    Science.gov (United States)

    Davis, Roger L.; Dannenhoffer, John F., III; Clark, John P.

    2010-01-01

    New ideas are forthcoming to break existing bottlenecks in using CFD during design. CAD-based automated grid generation. Multi-disciplinary use of embedded, overset grids to eliminate complex gridding problems. Use of time-averaged detached-eddy simulations as norm instead of "steady" RANS to include effects of self-excited unsteadiness. Combined GPU/Core parallel computing to provide over an order of magnitude increase in performance/price ratio. Gas-turbine applications are shown here but these ideas can be used for other Air Force, Navy, and NASA applications.

  17. Dynamics of the central bottleneck: dual-task and task uncertainty.

    Directory of Open Access Journals (Sweden)

    Mariano Sigman

    2006-07-01

    Full Text Available Why is the human brain fundamentally limited when attempting to execute two tasks at the same time or in close succession? Two classical paradigms, psychological refractory period (PRP and task switching, have independently approached this issue, making significant advances in our understanding of the architecture of cognition. Yet, there is an apparent contradiction between the conclusions derived from these two paradigms. The PRP paradigm, on the one hand, suggests that the simultaneous execution of two tasks is limited solely by a passive structural bottleneck in which the tasks are executed on a first-come, first-served basis. The task-switching paradigm, on the other hand, argues that switching back and forth between task configurations must be actively controlled by a central executive system (the system controlling voluntary, planned, and flexible action. Here we have explicitly designed an experiment mixing the essential ingredients of both paradigms: task uncertainty and task simultaneity. In addition to a central bottleneck, we obtain evidence for active processes of task setting (planning of the appropriate sequence of actions and task disengaging (suppression of the plan set for the first task in order to proceed with the next one. Our results clarify the chronometric relations between these central components of dual-task processing, and in particular whether they operate serially or in parallel. On this basis, we propose a hierarchical model of cognitive architecture that provides a synthesis of task-switching and PRP paradigms.

  18. The Now-or-Never bottleneck: A fundamental constraint on language.

    Science.gov (United States)

    Christiansen, Morten H; Chater, Nick

    2016-01-01

    Memory is fleeting. New material rapidly obliterates previous material. How, then, can the brain deal successfully with the continual deluge of linguistic input? We argue that, to deal with this "Now-or-Never" bottleneck, the brain must compress and recode linguistic input as rapidly as possible. This observation has strong implications for the nature of language processing: (1) the language system must "eagerly" recode and compress linguistic input; (2) as the bottleneck recurs at each new representational level, the language system must build a multilevel linguistic representation; and (3) the language system must deploy all available information predictively to ensure that local linguistic ambiguities are dealt with "Right-First-Time"; once the original input is lost, there is no way for the language system to recover. This is "Chunk-and-Pass" processing. Similarly, language learning must also occur in the here and now, which implies that language acquisition is learning to process, rather than inducing, a grammar. Moreover, this perspective provides a cognitive foundation for grammaticalization and other aspects of language change. Chunk-and-Pass processing also helps explain a variety of core properties of language, including its multilevel representational structure and duality of patterning. This approach promises to create a direct relationship between psycholinguistics and linguistic theory. More generally, we outline a framework within which to integrate often disconnected inquiries into language processing, language acquisition, and language change and evolution.

  19. [Bottlenecks in the provision of inpatient care--caused by the Hospital Funding Act].

    Science.gov (United States)

    Jansen, Christoph

    2010-01-01

    The responsibility of the state for ensuring the provision of hospital care services to its citizens derives from the welfare state principle laid down in Sect. 20 para. 1 GG (Grundgesetz, i.e., the German constitutional law). The state fulfils this responsibility by means of planning and funding regulations in the Hospital Funding Act (KHG), the Hospital Remuneration Act (KHEntG), the National Ordinance on Hospital Rates (BPflV), the Hospital Laws of the German federal states and other supplementary legislation. The funding of hospitals is based on a dual funding system, meaning that hospital investment costs generally need to be borne by the German federal states as required, while operating costs will have to be funded through the remuneration for hospital treatments. Because of the tight budget situation of the German federal states a considerable backlog of investment has built up. After a transition period (between 2005 and 2009) operating costs are now funded on the basis of the so-called DRG system (DRG=Diagnosis Related Groups)--irrespective of the actual costs incurred by each individual hospital, which has led to a commodification of hospital care services. Whether this commodification avoids bottlenecks in the provision of health services to hospital patients or creates additional bottlenecks, is a controversial issue. PMID:20870488

  20. Topological-based bottleneck analysis and improvement strategies for traffic networks

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A method is proposed to find key components of traffic networks with homogenous and heterogeneous topologies, in which heavier traffic flow is transported. One component, called the skeleton, is the minimum spanning tree (MST) based on the zero flow cost (ZCMST). The other component is the infinite incipient percolation cluster (IIC) which represents the spine of the traffic network. Then, a new method to analysis the property of the bottleneck in a large scale traffic network is given from a macroscopic and statistical viewpoint. Moreover, three effective strategies are proposed to alleviate traffic congestion. The significance of the findings is that one can significantly improve the global transport by enhancing the capacity in the ZCMST with a few links, while for improving the local traffic property, improving a tiny fraction of the traffic network in the IIC is effective. The result can be used to help traffic managers prevent and alleviate traffic congestion in time, guard against the formation of congestion bottleneck, and make appropriate policies for traffic demand management. Meanwhile, the method has very important theoretical significance and practical worthiness in optimizing traffic organization, traffic control, and disposal of emergency.

  1. Note: Inhibiting bottleneck corrosion in electrical calcium tests for ultra-barrier measurements

    Energy Technology Data Exchange (ETDEWEB)

    Nehm, F., E-mail: frederik.nehm@iapp.de; Müller-Meskamp, L.; Klumbies, H.; Leo, K. [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany)

    2015-12-15

    A major failure mechanism is identified in electrical calcium corrosion tests for quality assessment of high-end application moisture barriers. Accelerated calcium corrosion is found at the calcium/electrode junction, leading to an electrical bottleneck. This causes test failure not related to overall calcium loss. The likely cause is a difference in electrochemical potential between the aluminum electrodes and the calcium sensor, resulting in a corrosion element. As a solution, a thin, full-area copper layer is introduced below the calcium, shifting the corrosion element to the calcium/copper junction and inhibiting bottleneck degradation. Using the copper layer improves the level of sensitivity for the water vapor transmission rate (WVTR) by over one order of magnitude. Thin-film encapsulated samples with 20 nm of atomic layer deposited alumina barriers this way exhibit WVTRs of 6 × 10{sup −5} g(H{sub 2}O)/m{sup 2}/d at 38 °C, 90% relative humidity.

  2. Genetic diversity of native Turkish cattle breeds: Mantel, AMOVA and bottleneck analysis

    Directory of Open Access Journals (Sweden)

    Yusuf Özşensoy

    2014-09-01

    Full Text Available This study was conducted to evaluate potential extinction risk of Turkish native cattle breeds using Mantel and AMOVA tests and Bottleneck analysis. A total of 271 DNA samples were isolated from Anatolian Black, Anatolian Grey, South Anatolian Red, Native Southern Anatolian Yellow, East Anatolian Red, and Zavot cattle. In this study, genotypes of 20 microsatellites were determined by capillary electrophoresis and fragment analysis. A total of 269 different alleles were detected. The maximum and minimum numbers of total alleles were observed in TGLA122 (n=26 and INRA005 (n=7 loci, respectively. The highest average observed and expected heterozygosity values were determined as 0.619–0.852 and 0.669–0.877, respectively. The average FIS value was 0.068. Results of AMOVA and Mantel tests illustrated statistically significant differences in populations (p<0.001 and correlation (p<0.01. Bottleneck analysis revealed a normal distribution of L–shaped curve indicating that there was no recent risk of extinction for these breeds.

  3. Fast electronic relaxation in metal nanoclusters via excitation of coherent shape deformations: Circumventing a bottleneck

    CERN Document Server

    Kresin, V V; Kresin, Vitaly V.; Ovchinnikov, Yu. N.

    2006-01-01

    Electron-phonon relaxation in size-quantized systems may become inhibited when the spacing of discrete electron energy levels exceeds the magnitude of the phonon frequency. We show, however, that nanoclusters can support a fast nonradiative relaxation channel which derives from their distinctive ability to undergo Jahn-Teller shape deformations. Such a deformation represents a collective and coherent vibrational excitation and enables electronic transitions to occur without a multiphonon bottleneck. We analyze this mechanism for a metal cluster within the analytical framework of a three-dimensional potential well undergoing a spheroidal distortion. An expression for the time evolution of the distortion parameter is derived, the electronic level crossing condition formulated, and the probability of electronic transition at a level crossing is evaluated. An application to electron-hole recombination in a closed-shell aluminum cluster with 40 electrons shows that the short (~250 fs) excitation lifetime observed ...

  4. Bottlenecks, burstiness, and fat tails regulate mixing times of non-Poissonian random walks

    CERN Document Server

    Delvenne, Jean-Charles; Rocha, Luis E C

    2013-01-01

    We focus on general continuous-time random walks on networks and find that the mixing time, i.e. the relaxation time for the random process to reach stationarity, is determined by a combination of three factors: the spectral gap, associated to bottlenecks in the underlying topology, burstiness, related to the second moment of the waiting time distribution, and the characteristic time of its exponential tail, which is an indicator of the tail `fatness'. We show theoretically that a strong modular structure dampens the importance of burstiness, and empirically that either of the three factors may be dominant in real-life data. These results provide a theoretical framework for the modeling of diffusion on temporal networks representing human interactions, often characterized by non-Poissonian contact patterns.

  5. Phonon bottleneck in p-type Ge/Si quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Yakimov, A. I., E-mail: yakimov@isp.nsc.ru [Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Science, 630090 Novosibirsk (Russian Federation); Tomsk State University, 634050 Tomsk (Russian Federation); Kirienko, V. V.; Armbrister, V. A. [Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Science, 630090 Novosibirsk (Russian Federation); Bloshkin, A. A.; Dvurechenskii, A. V. [Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Science, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation)

    2015-11-23

    We study the effect of quantum dot size on the mid-infrared photo- and dark current, photoconductive gain, and hole capture probability in ten-period p-type Ge/Si quantum dot heterostructures. The dot dimensions are varied by changing the Ge coverage and the growth temperature during molecular beam epitaxy of Ge/Si(001) system in the Stranski-Krastanov growth mode. In all samples, we observed the general tendency: with decreasing the size of the dots, the dark current and hole capture probability are reduced, while the photoconductive gain and photoresponse are enhanced. Suppression of the hole capture probability in small-sized quantum dots is attributed to a quenched electron-phonon scattering due to phonon bottleneck.

  6. Head-of-tide bottleneck of particulate material transport from watersheds to estuaries

    Science.gov (United States)

    Ensign, Scott H.; Noe, Gregory; Hupp, Cliff R.; Skalak, Katherine

    2015-01-01

    We measured rates of sediment, C, N, and P accumulation at four floodplain sites spanning the nontidal through oligohaline Choptank and Pocomoke Rivers, Maryland, USA. Ceramic tiles were used to collect sediment for a year and sediment cores were collected to derive decadal sedimentation rates using 137Cs. The results showed highest rates of short- and long-term sediment, C, N, and P accumulation occurred in tidal freshwater forests at the head of tide on the Choptank and the oligohaline marsh of the Pocomoke River, and lowest rates occurred in the downstream tidal freshwater forests in both rivers. Presumably, watershed material was mostly trapped at the head of tide, and estuarine material was trapped in oligohaline marshes. This hydrologic transport bottleneck at the head of tide stores most available watershed sediment, C, N, and P creating a sediment shadow in lower tidal freshwater forests potentially limiting their resilience to sea level rise.

  7. Engineering oilseeds for sustainable production of industrial and nutritional feedstocks: solving bottlenecks in fatty acid flux.

    Science.gov (United States)

    Cahoon, Edgar B; Shockey, Jay M; Dietrich, Charles R; Gidda, Satinder K; Mullen, Robert T; Dyer, John M

    2007-06-01

    Oilseeds provide a unique platform for the production of high-value fatty acids that can replace non-sustainable petroleum and oceanic sources of specialty chemicals and aquaculture feed. However, recent efforts to engineer the seeds of crop and model plant species to produce new types of fatty acids, including hydroxy and conjugated fatty acids for industrial uses and long-chain omega-3 polyunsaturated fatty acids for farmed fish feed, have met with only modest success. The collective results from these studies point to metabolic 'bottlenecks' in the engineered plant seeds that substantially limit the efficient or selective flux of unusual fatty acids between different substrate pools and ultimately into storage triacylglycerol. Evidence is emerging that diacylglycerol acyltransferase 2, which catalyzes the final step in triacylglycerol assembly, is an important contributor to the synthesis of unusual fatty acid-containing oils, and is likely to be a key target for future oilseed metabolic engineering efforts. PMID:17434788

  8. Algorithm Based on Taboo Search and Shifting Bottleneck for Job Shop Scheduling

    Institute of Scientific and Technical Information of China (English)

    Wen-Qi Huang; Zhi Huang

    2004-01-01

    In this paper, a computational effective heuristic method for solving the minimum makespan problem of job shop scheduling is presented. It is based on taboo search procedure and on the shifting bottleneck procedure used to jump out of the trap of the taboo search procedure. A key point of the algorithm is that in the taboo search procedure two taboo lists are used to forbid two kinds of reversals of arcs, which is a new and effective way in taboo search methods for job shop scheduling. Computational experiments on a set of benchmark problem instances show that, in several cases, the approach, in reasonable time, yields better solutions than the other heuristic procedures discussed in the literature.

  9. Approximation Algorithm for Bottleneck Steiner Tree Problem in the Euclidean Plane

    Institute of Scientific and Technical Information of China (English)

    Zi-Mao Li; Da-Ming Zhu; Shao-Han Ma

    2004-01-01

    A special case of the bottleneck Steiner tree problem in the Euclidean plane was considered in this paper. The problem has applications in the design of wireless communication networks, multifacility location, VLSI routing and network routing. For the special case which requires that there should be no edge connecting any two Steiner points in the optimal solution, a 3-restricted Steiner tree can be found indicating the existence of the performance ratio √2. In this paper, the special case of the problem is proved to be NP-hard and cannot be approximated within ratio √2. First a simple polynomial time approximation algorithm with performance ratio √3 is presented. Then based on this algorithm and the existence of the 3-restricted Steiner tree, a polynomial time approximation algorithm with performance ratio-√2 + ε is proposed, for any ε>0.

  10. Fixation times in differentiation and evolution in the presence of bottlenecks, deserts, and oases.

    Science.gov (United States)

    Chou, Tom; Wang, Yu

    2015-05-01

    Cellular differentiation and evolution are stochastic processes that can involve multiple types (or states) of particles moving on a complex, high-dimensional state-space or "fitness" landscape. Cells of each specific type can thus be quantified by their population at a corresponding node within a network of states. Their dynamics across the state-space network involve genotypic or phenotypic transitions that can occur upon cell division, such as during symmetric or asymmetric cell differentiation, or upon spontaneous mutation. Here, we use a general multi-type branching processes to study first passage time statistics for a single cell to appear in a specific state. Our approach readily allows for nonexponentially distributed waiting times between transitions, reflecting, e.g., the cell cycle. For simplicity, we restrict most of our detailed analysis to exponentially distributed waiting times (Poisson processes). We present results for a sequential evolutionary process in which L successive transitions propel a population from a "wild-type" state to a given "terminally differentiated," "resistant," or "cancerous" state. Analytic and numeric results are also found for first passage times across an evolutionary chain containing a node with increased death or proliferation rate, representing a desert/bottleneck or an oasis. Processes involving cell proliferation are shown to be "nonlinear" (even though mean-field equations for the expected particle numbers are linear) resulting in first passage time statistics that depend on the position of the bottleneck or oasis. Our results highlight the sensitivity of stochastic measures to cell division fate and quantify the limitations of using certain approximations (such as the fixed-population and mean-field assumptions) in evaluating fixation times.

  11. Reducing the Disk IO Bandwidth Bottleneck through Fast Floating Point Compression using Accelerators

    Directory of Open Access Journals (Sweden)

    Ajith Padyana

    2014-03-01

    Full Text Available Compute-intensive tasks in high-end high performance computing (HPC systems often generate large amounts of data, especially floating-point data that need to be transmitted over the network. Although computation speeds are very high, the overall performance of these applications is affected by the data transfer overhead. Moreover, as data sets are growing in size rapidly, bandwidth limitations pose a serious bottleneck in several scientific applications. Fast floating point compression can ameliorate the bandwidth limitations. If data is compressed well, then the amount of data transfer is reduced. This reduction in data transfer time comes at the expense of the increased computation required by compression and decompression. It is important for compression and decompression rates to be greater than the network bandwidth; otherwise, it will be faster to transmit uncompressed data directly [1]. Accelerators such as Graphics Processing Units (GPU provide much computational power. In this paper, we show that the computational power of GPUs and CellBE processor can be harnessed to provide sufficiently fast compression and decompression for this approach to be effective for data produced by many practical applications. In particularly, we use Holt`s Exponential smoothing algorithm from time series analysis, and encode the difference between its predictions and the actual data. This yields a lossless compression scheme. We show that it can be implemented efficiently on GPUs and CellBE to provide an effective compression scheme for the purpose of saving on data transfer overheads The primary contribution of this work lies in demonstrating the potential of floating point compression in reducing the I/O bandwidth bottleneck on modern hardware for important classes of scientific applications.

  12. Capacity drop: A comparison between stop-and-go wave and standing queue at lane-drop bottleneck

    NARCIS (Netherlands)

    Yuan, K.; Knoop, V.L.; Leclercq, L.; Hoogendoorn, S.P.

    2014-01-01

    In freeways, the maximum traffic flow through a bottleneck is usually higher than the outflow of congestion there. This phenomenon is called the capacity drop. In literature, there are considerable debates about the mechanism causing this phenomenon. This paper studies the mechanism by analyzing rea

  13. Diversity and stability of Aleutian mink disease virus during bottleneck transitions resulting from eradication in domestic mink in Denmark

    DEFF Research Database (Denmark)

    Christensen, Laurids Siig; Hansen, Lene Gram; Chriél, Mariann;

    2011-01-01

    cluster compared with Swedish, Finnish and Dutch isolates and seem to represent a minor fraction of the genetic diversity previously found in Denmark. Stability of nucleoide deviations reveals that the purifying selection of bottlenecks imposed on the AMDV population in Denmark by the stamping out policy...

  14. A decomposition heuristics based on multi-bottleneck machines for large-scale job shop scheduling problems

    Directory of Open Access Journals (Sweden)

    Yingni Zhai

    2014-10-01

    Full Text Available Purpose: A decomposition heuristics based on multi-bottleneck machines for large-scale job shop scheduling problems (JSP is proposed.Design/methodology/approach: In the algorithm, a number of sub-problems are constructed by iteratively decomposing the large-scale JSP according to the process route of each job. And then the solution of the large-scale JSP can be obtained by iteratively solving the sub-problems. In order to improve the sub-problems' solving efficiency and the solution quality, a detection method for multi-bottleneck machines based on critical path is proposed. Therewith the unscheduled operations can be decomposed into bottleneck operations and non-bottleneck operations. According to the principle of “Bottleneck leads the performance of the whole manufacturing system” in TOC (Theory Of Constraints, the bottleneck operations are scheduled by genetic algorithm for high solution quality, and the non-bottleneck operations are scheduled by dispatching rules for the improvement of the solving efficiency.Findings: In the process of the sub-problems' construction, partial operations in the previous scheduled sub-problem are divided into the successive sub-problem for re-optimization. This strategy can improve the solution quality of the algorithm. In the process of solving the sub-problems, the strategy that evaluating the chromosome's fitness by predicting the global scheduling objective value can improve the solution quality.Research limitations/implications: In this research, there are some assumptions which reduce the complexity of the large-scale scheduling problem. They are as follows: The processing route of each job is predetermined, and the processing time of each operation is fixed. There is no machine breakdown, and no preemption of the operations is allowed. The assumptions should be considered if the algorithm is used in the actual job shop.Originality/value: The research provides an efficient scheduling method for the

  15. A single origin and moderate bottleneck during domestication of soybean (Glycine max): implications from microsatellites and nucleotide sequences.

    Science.gov (United States)

    Guo, Juan; Wang, Yunsheng; Song, Chi; Zhou, Jianfeng; Qiu, Lijuan; Huang, Hongwen; Wang, Ying

    2010-09-01

    Background and Aims It is essential to illuminate the evolutionary history of crop domestication in order to understand further the origin and development of modern cultivation and agronomy; however, despite being one of the most important crops, the domestication origin and bottleneck of soybean (Glycine max) are poorly understood. In the present study, microsatellites and nucleotide sequences were employed to elucidate the domestication genetics of soybean. Methods The genomes of 79 landrace soybeans (endemic cultivated soybeans) and 231 wild soybeans (G. soja) that represented the species-wide distribution of wild soybean in East Asia were scanned with 56 microsatellites to identify the genetic structure and domestication origin of soybean. To understand better the domestication bottleneck, four nucleotide sequences were selected to simulate the domestication bottleneck. Key Results Model-based analysis revealed that most of the landrace genotypes were assigned to the inferred wild soybean cluster of south China, South Korea and Japan. Phylogeny for wild and landrace soybeans showed that all landrace soybeans formed a single cluster supporting a monophyletic origin of all the cultivars. The populations of the nearest branches which were basal to the cultivar lineage were wild soybeans from south China. The coalescent simulation detected a bottleneck severity of K' = 2 during soybean domestication, which could be explained by a foundation population of 6000 individuals if domestication duration lasted 3000 years. Conclusions As a result of integrating geographic distribution with microsatellite genotype assignment and phylogeny between landrace and wild soybeans, a single origin of soybean in south China is proposed. The coalescent simulation revealed a moderate genetic bottleneck with an effective wild soybean population used for domestication estimated to be approximately 2 % of the total number of ancestral wild soybeans. Wild soybeans in Asia, especially in

  16. Population structure and genetic bottleneck in sweet cherry estimated with SSRs and the gametophytic self-incompatibility locus

    Directory of Open Access Journals (Sweden)

    Mariette Stéphanie

    2010-08-01

    Full Text Available Abstract Background Domestication and breeding involve the selection of particular phenotypes, limiting the genomic diversity of the population and creating a bottleneck. These effects can be precisely estimated when the location of domestication is established. Few analyses have focused on understanding the genetic consequences of domestication and breeding in fruit trees. In this study, we aimed to analyse genetic structure and changes in the diversity in sweet cherry Prunus avium L. Results Three subgroups were detected in sweet cherry, with one group of landraces genetically very close to the analysed wild cherry population. A limited number of SSR markers displayed deviations from the frequencies expected under neutrality. After the removal of these markers from the analysis, a very limited bottleneck was detected between wild cherries and sweet cherry landraces, with a much more pronounced bottleneck between sweet cherry landraces and modern sweet cherry varieties. The loss of diversity between wild cherries and sweet cherry landraces at the S-locus was more significant than that for microsatellites. Particularly high levels of differentiation were observed for some S-alleles. Conclusions Several domestication events may have happened in sweet cherry or/and intense gene flow from local wild cherry was probably maintained along the evolutionary history of the species. A marked bottleneck due to breeding was detected, with all markers, in the modern sweet cherry gene pool. The microsatellites did not detect the bottleneck due to domestication in the analysed sample. The vegetative propagation specific to some fruit trees may account for the differences in diversity observed at the S-locus. Our study provides insights into domestication events of cherry, however, requires confirmation on a larger sampling scheme for both sweet cherry landraces and wild cherry.

  17. Smart-pixel-based free-space interconnects: solving the high-speed multichip packaging bottleneck

    Science.gov (United States)

    Haney, Michael W.; Christensen, Marc P.; Milojkovic, Predrag; McFadden, Michael J.

    2001-11-01

    As IC densities grow to 100's of millions of devices per chip and beyond, the inter-chip link bandwidth becomes a critical performance-limiting bottleneck in many applications. Electronic packaging technology has not kept pace with the growth of IC I/O requirements. Recent advances in smart pixel technology, however, offer the potential to use 3-D optical interconnects to overcome the inter-chip I/O bottleneck by linking dense arrays of Vertical Cavity Surface Emitting Lasers (VCSELs) and photodetectors, which are directly integrated onto electronic IC circuits. Many switching and parallel computing applications demand multi-chip interconnection fabrics that achieve high-density global I/O across an array of chips. Such global interconnections require a high degree of space-variance in the interconnection fabric, in addition to high inter-chip throughput capacity. This paper reviews the architectural and optical design issues associated with global interconnections among arrays of chips. The emphasis is on progress made in the design and implementation of the second generation Free-space Accelerator for Switching Terabit Networks (FAST-Net) prototype. The FAST-Net prototype uses a macro-optical lens array and mirror to effect a global (fully connected) fabric across a 4 X 4 array of smart pixel chips. Clusters of VCSELs and photodetectors are imaged onto corresponding clusters on other chips, creating a high- density bi-directional data path between every pair of smart pixel chips on a multi-chip module. The combination of programmable intra-chip electronic routing and the fixed global inter-chip optical interconnection pattern of the FAST- Net architecture has been shown to provide a low latency, minimum complexity fabric, that can effect an arbitrary interconnection pattern across the chip array. Recent experimental results show that the narrow beam characteristics of VCSELs can be exploited in an efficient optical design for the FAST-Net optical interconnection

  18. Genetic architecture and bottleneck analyses of Salem Black goat breed based on microsatellite markers

    Directory of Open Access Journals (Sweden)

    A. K. Thiruvenkadan

    2014-09-01

    Full Text Available Aim: The present study was undertaken in Salem Black goat population for genetic analysis at molecular level to exploit the breed for planning sustainable improvement, conservation and utilization, which subsequently can improve the livelihood of its stakeholders. Materials and Methods: Genomic DNA was isolated from blood samples of 50 unrelated Salem Black goats with typical phenotypic features in several villages in the breeding tract and the genetic characterization and bottleneck analysis in Salem Black goat was done using 25 microsatellite markers as recommended by the Food and Agricultural Organization, Rome, Italy. The basic measures of genetic variation were computed using bioinformatic software. To evaluate the Salem Black goats for mutation drift equilibrium, three tests were performed under three different mutation models, viz., infinite allele model (IAM, stepwise mutation model (SMM and two-phase model (TPM and the observed gene diversity (He and expected equilibrium gene diversity (Heq were estimated under different models of microsatellite evolution. Results: The study revealed that the observed number of alleles ranged from 4 (ETH10, ILSTS008 to 17 (BM64444 with a total of 213 alleles and mean of 10.14±0.83 alleles across loci. The overall observed heterozygosity, expected heterozygosity, inbreeding estimate and polymorphism information content values were 0.631±0.041, 0.820±0.024, 0.233±0.044 and 0.786±0.023 respectively indicating high genetic diversity. The average observed gene diversities (He pooled over different markers was 0.829±0.024 and the average expected gene diversities under IAM, TPM and SMM models were 0.769±0.026, 0.808±0.024 and 0.837±0.020 respectively. The number of loci found to exhibit gene diversity excess under IAM, TPM and SMM models were 18, 17 and 12 respectively. Conclusion: All the three statistical tests, viz., sign test, standardized differences test and Wilcoxon sign rank test, revealed

  19. Independent bottlenecks characterize colonization of systemic compartments and gut lymphoid tissue by salmonella.

    Directory of Open Access Journals (Sweden)

    Chee Han Lim

    2014-07-01

    Full Text Available Vaccination represents an important instrument to control typhoid fever in humans and protects mice from lethal infection with mouse pathogenic serovars of Salmonella species. Mixed infections with tagged Salmonella can be used in combination with probabilistic models to describe the dynamics of the infection process. Here we used mixed oral infections with tagged Salmonella strains to identify bottlenecks in the infection process in naïve and vaccinated mice. We established a next generation sequencing based method to characterize the composition of tagged Salmonella strains which offers a fast and reliable method to characterise the composition of genome-tagged Salmonella strains. We show that initial colonization of Salmonella was distinguished by a non-Darwinian selection of few bacteria setting up the infection independently in gut associated lymphoid tissue and systemic compartments. Colonization of Peyer's patches fuels the sustained spread of bacteria into mesenteric lymph nodes via dendritic cells. In contrast, infection of liver and spleen originated from an independent pool of bacteria. Vaccination only moderately reduced invasion of Peyer's patches but potently uncoupled bacterial populations present in different systemic compartments. Our data indicate that vaccination differentially skews the capacity of Salmonella to colonize systemic and gut immune compartments and provide a framework for the further dissection of infection dynamics.

  20. Independent bottlenecks characterize colonization of systemic compartments and gut lymphoid tissue by salmonella.

    Science.gov (United States)

    Lim, Chee Han; Voedisch, Sabrina; Wahl, Benjamin; Rouf, Syed Fazle; Geffers, Robert; Rhen, Mikael; Pabst, Oliver

    2014-07-01

    Vaccination represents an important instrument to control typhoid fever in humans and protects mice from lethal infection with mouse pathogenic serovars of Salmonella species. Mixed infections with tagged Salmonella can be used in combination with probabilistic models to describe the dynamics of the infection process. Here we used mixed oral infections with tagged Salmonella strains to identify bottlenecks in the infection process in naïve and vaccinated mice. We established a next generation sequencing based method to characterize the composition of tagged Salmonella strains which offers a fast and reliable method to characterise the composition of genome-tagged Salmonella strains. We show that initial colonization of Salmonella was distinguished by a non-Darwinian selection of few bacteria setting up the infection independently in gut associated lymphoid tissue and systemic compartments. Colonization of Peyer's patches fuels the sustained spread of bacteria into mesenteric lymph nodes via dendritic cells. In contrast, infection of liver and spleen originated from an independent pool of bacteria. Vaccination only moderately reduced invasion of Peyer's patches but potently uncoupled bacterial populations present in different systemic compartments. Our data indicate that vaccination differentially skews the capacity of Salmonella to colonize systemic and gut immune compartments and provide a framework for the further dissection of infection dynamics.

  1. Only adding stationary storage to vaccine supply chains may create and worsen transport bottlenecks.

    Science.gov (United States)

    Haidari, Leila A; Connor, Diana L; Wateska, Angela R; Brown, Shawn T; Mueller, Leslie E; Norman, Bryan A; Schmitz, Michelle M; Paul, Proma; Rajgopal, Jayant; Welling, Joel S; Leonard, Jim; Claypool, Erin G; Weng, Yu-Ting; Chen, Sheng-I; Lee, Bruce Y

    2013-01-01

    Although vaccine supply chains in many countries require additional stationary storage and transport capacity to meet current and future needs, international donors tend to donate stationary storage devices far more often than transport equipment. To investigate the impact of only adding stationary storage equipment on the capacity requirements of transport devices and vehicles, we used HERMES (Highly Extensible Resource for Modeling Supply Chains) to construct a discrete event simulation model of the Niger vaccine supply chain. We measured the transport capacity requirement for each mode of transport used in the Niger vaccine cold chain, both before and after adding cold rooms and refrigerators to relieve all stationary storage constraints in the system. With the addition of necessary stationary storage, the average transport capacity requirement increased from 88% to 144% for cold trucks, from 101% to 197% for pickup trucks, and from 366% to 420% for vaccine carriers. Therefore, adding stationary storage alone may worsen or create new transport bottlenecks as more vaccines flow through the system, preventing many vaccines from reaching their target populations. Dynamic modeling can reveal such relationships between stationary storage capacity and transport constraints.

  2. Photodegradation alleviates the lignin bottleneck for carbon turnover in terrestrial ecosystems.

    Science.gov (United States)

    Austin, Amy T; Méndez, M Soledad; Ballaré, Carlos L

    2016-04-19

    A mechanistic understanding of the controls on carbon storage and losses is essential for our capacity to predict and mitigate human impacts on the global carbon cycle. Plant litter decomposition is an important first step for carbon and nutrient turnover, and litter inputs and losses are essential in determining soil organic matter pools and the carbon balance in terrestrial ecosystems. Photodegradation, the photochemical mineralization of organic matter, has been recently identified as a mechanism for previously unexplained high rates of litter mass loss in arid lands; however, the global significance of this process as a control on carbon cycling in terrestrial ecosystems is not known. Here we show that, across a wide range of plant species, photodegradation enhanced subsequent biotic degradation of leaf litter. Moreover, we demonstrate that the mechanism for this enhancement involves increased accessibility to plant litter carbohydrates for microbial enzymes. Photodegradation of plant litter, driven by UV radiation, and especially visible (blue-green) light, reduced the structural and chemical bottleneck imposed by lignin in secondary cell walls. In leaf litter from woody species, specific interactions with UV radiation obscured facilitative effects of solar radiation on biotic decomposition. The generalized effect of sunlight exposure on subsequent microbial activity, mediated by increased accessibility to cell wall polysaccharides, suggests that photodegradation is quantitatively important in determining rates of mass loss, nutrient release, and the carbon balance in a broad range of terrestrial ecosystems.

  3. Development and bottlenecks of renewable electricity generation in China: a critical review.

    Science.gov (United States)

    Hu, Yuanan; Cheng, Hefa

    2013-04-01

    This review provides an overview on the development and status of electricity generation from renewable energy sources, namely hydropower, wind power, solar power, biomass energy, and geothermal energy, and discusses the technology, policy, and finance bottlenecks limiting growth of the renewable energy industry in China. Renewable energy, dominated by hydropower, currently accounts for more than 25% of the total electricity generation capacity. China is the world's largest generator of both hydropower and wind power, and also the largest manufacturer and exporter of photovoltaic cells. Electricity production from solar and biomass energy is at the early stages of development in China, while geothermal power generation has received little attention recently. The spatial mismatch in renewable energy supply and electricity demand requires construction of long-distance transmission networks, while the intermittence of renewable energy poses significant technical problems for feeding the generated electricity into the power grid. Besides greater investment in research and technology development, effective policies and financial measures should also be developed and improved to better support the healthy and sustained growth of renewable electricity generation. Meanwhile, attention should be paid to the potential impacts on the local environment from renewable energy development, despite the wider benefits for climate change. PMID:23445126

  4. Fluctuating bottleneck model studies on kinetics of DNA escape from α-hemolysin nanopores.

    Science.gov (United States)

    Bian, Yukun; Wang, Zilin; Chen, Anpu; Zhao, Nanrong

    2015-11-14

    We have proposed a fluctuation bottleneck (FB) model to investigate the non-exponential kinetics of DNA escape from nanometer-scale pores. The basic idea is that the escape rate is proportional to the fluctuating cross-sectional area of DNA escape channel, the radius r of which undergoes a subdiffusion dynamics subjected to fractional Gaussian noise with power-law memory kernel. Such a FB model facilitates us to obtain the analytical result of the averaged survival probability as a function of time, which can be directly compared to experimental results. Particularly, we have applied our theory to address the escape kinetics of DNA through α-hemolysin nanopores. We find that our theoretical framework can reproduce the experimental results very well in the whole time range with quite reasonable estimation for the intrinsic parameters of the kinetics processes. We believe that FB model has caught some key features regarding the long time kinetics of DNA escape through a nanopore and it might provide a sound starting point to study much wider problems involving anomalous dynamics in confined fluctuating channels. PMID:26567685

  5. Calculation of the mean circle size does not circumvent the bottleneck of crowding.

    Science.gov (United States)

    Banno, Hayaki; Saiki, Jun

    2012-10-22

    Visually, we can extract a statistical summary of sets of elements efficiently. However, our visual system has a severe limitation in that the ability to recognize an object is remarkably impaired when it is surrounded by other objects. The goal of this study was to investigate whether the crowding effect obstructs the calculation of the mean size of objects. First, we verified that the crowding effect occurs when comparing the sizes of circles (Experiment 1). Next, we manipulated the distances between circles and measured the sensitivity when circles were on or off the limitation of crowding (Experiment 2). Participants were asked to compare the mean sizes of the circles in the left and right visual fields and to judge which was larger. Participants' sensitivity to mean size difference was lower when the circles were located in the nearer distance. Finally, we confirmed that crowding is responsible for the observed results by showing that displays without a crowded object eliminated the effects (Experiment 3). Our results indicate that the statistical information of size does not circumvent the bottleneck of crowding.

  6. Photodegradation alleviates the lignin bottleneck for carbon turnover in terrestrial ecosystems.

    Science.gov (United States)

    Austin, Amy T; Méndez, M Soledad; Ballaré, Carlos L

    2016-04-19

    A mechanistic understanding of the controls on carbon storage and losses is essential for our capacity to predict and mitigate human impacts on the global carbon cycle. Plant litter decomposition is an important first step for carbon and nutrient turnover, and litter inputs and losses are essential in determining soil organic matter pools and the carbon balance in terrestrial ecosystems. Photodegradation, the photochemical mineralization of organic matter, has been recently identified as a mechanism for previously unexplained high rates of litter mass loss in arid lands; however, the global significance of this process as a control on carbon cycling in terrestrial ecosystems is not known. Here we show that, across a wide range of plant species, photodegradation enhanced subsequent biotic degradation of leaf litter. Moreover, we demonstrate that the mechanism for this enhancement involves increased accessibility to plant litter carbohydrates for microbial enzymes. Photodegradation of plant litter, driven by UV radiation, and especially visible (blue-green) light, reduced the structural and chemical bottleneck imposed by lignin in secondary cell walls. In leaf litter from woody species, specific interactions with UV radiation obscured facilitative effects of solar radiation on biotic decomposition. The generalized effect of sunlight exposure on subsequent microbial activity, mediated by increased accessibility to cell wall polysaccharides, suggests that photodegradation is quantitatively important in determining rates of mass loss, nutrient release, and the carbon balance in a broad range of terrestrial ecosystems. PMID:27044070

  7. Circum-planetary discs as bottlenecks for gas accretion onto giant planets

    CERN Document Server

    Rivier, Guillaume; Morbidelli, Alessandro; Brouet, Yann

    2012-01-01

    With hundreds of exoplanets detected, it is necessary to revisit giant planets accretion models to explain their mass distribution. In particular, formation of sub-jovian planets remains unclear, given the short timescale for the runaway accretion of massive atmospheres. However, gas needs to pass through a circum-planetary disc. If the latter has a low viscosity (as expected if planets form in "dead zones"), it might act as a bottleneck for gas accretion. We investigate what the minimum accretion rate is for a planet under the limit assumption that the circum-planetary disc is totally inviscid, and the transport of angular momentum occurs solely because of the gravitational perturbations from the star. To estimate the accretion rate, we present a steady-state model of an inviscid circum-planetary disc, with vertical gas inflow and external torque from the star. Hydrodynamical simulations of a circum-planetary disc were conducted in 2D, in a planetocentric frame, with the star as an external perturber in orde...

  8. Metabolic Engineering of Yeast to Produce Fatty Acid-derived Biofuels: Bottlenecks and Solutions

    Directory of Open Access Journals (Sweden)

    Jiayuan eSheng

    2015-06-01

    Full Text Available Fatty acid-derived biofuels can be a better solution than bioethanol to replace petroleum fuel, since they have similar energy content and combustion properties as current transportation fuels. The environmentally friendly microbial fermentation process has been used to synthesize advanced biofuels from renewable feedstock. Due to their robustness as well as the high tolerance to fermentation inhibitors and phage contamination, yeast strains such as Saccharomyces cerevisiae and Yarrowia lipolytica have attracted tremendous attention in recent studies regarding the production of fatty acid-derived biofuels, including fatty acids, fatty acid ethyl esters, fatty alcohols, and fatty alkanes. However, the native yeast strains cannot produce fatty acids and fatty acid-derived biofuels in large quantities. To this end, we have summarized recent publications in this review on metabolic engineering of yeast strains to improve the production of fatty acid-derived biofuels, identified the bottlenecks that limit the productivity of biofuels, and categorized the appropriate approaches to overcome these obstacles.

  9. Neutron capture cross section of $^{90}$Zr Bottleneck in the s-process reaction flow

    CERN Document Server

    Tagliente, G; Milazzo, P M; Moreau, C; Aerts, G; Abbondanno, U; Alvarez, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, Panayiotis; Audouin, L; Badurek, G; Baumann, P; Bečvář, F; Berthoumieux, E; Bisterzo, S; Calviño, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapiço, C; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Domingo-Pardo, C; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Furman, W; Gallino, R; Gonçalves, I; Gonzalez-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Köhler, P; Kossionides, E; Krtička, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martínez, T; Massimi, C; Mastinu, P; Mengoni, A; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Santos, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M, C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2008-01-01

    The neutron capture cross sections of the Zr isotopes have important implications in nuclear astrophysics and for reactor design. The small cross section of the neutron magic nucleus 90Zr, which accounts for more than 50% of natural zirconium represents one of the key isotopes for the stellar s-process, because it acts as a bottleneck in the neutron capture chain between the Fe seed and the heavier isotopes. The same element, Zr, also is an important component of the structural materials used in traditional and advanced nuclear reactors. The (n,γ) cross section has been measured at CERN, using the n_TOF spallation neutron source. In total, 45 resonances could be resolved in the neutron energy range below 70 keV, 10 being observed for the first time thanks to the high resolution and low backgrounds at n_TOF. On average, the Γγ widths obtained in resonance analyses with the R-matrix code SAMMY were 15% smaller than reported previously. By these results, the accuracy of the Maxwellian averaged cross section f...

  10. Only adding stationary storage to vaccine supply chains may create and worsen transport bottlenecks.

    Science.gov (United States)

    Haidari, Leila A; Connor, Diana L; Wateska, Angela R; Brown, Shawn T; Mueller, Leslie E; Norman, Bryan A; Schmitz, Michelle M; Paul, Proma; Rajgopal, Jayant; Welling, Joel S; Leonard, Jim; Claypool, Erin G; Weng, Yu-Ting; Chen, Sheng-I; Lee, Bruce Y

    2013-01-01

    Although vaccine supply chains in many countries require additional stationary storage and transport capacity to meet current and future needs, international donors tend to donate stationary storage devices far more often than transport equipment. To investigate the impact of only adding stationary storage equipment on the capacity requirements of transport devices and vehicles, we used HERMES (Highly Extensible Resource for Modeling Supply Chains) to construct a discrete event simulation model of the Niger vaccine supply chain. We measured the transport capacity requirement for each mode of transport used in the Niger vaccine cold chain, both before and after adding cold rooms and refrigerators to relieve all stationary storage constraints in the system. With the addition of necessary stationary storage, the average transport capacity requirement increased from 88% to 144% for cold trucks, from 101% to 197% for pickup trucks, and from 366% to 420% for vaccine carriers. Therefore, adding stationary storage alone may worsen or create new transport bottlenecks as more vaccines flow through the system, preventing many vaccines from reaching their target populations. Dynamic modeling can reveal such relationships between stationary storage capacity and transport constraints. PMID:23903398

  11. 城市轨道交通车站动态瓶颈识别方法研究%Identification of Dynamic Bottlenecks of Urban Rail Transit Stations

    Institute of Scientific and Technical Information of China (English)

    黄令海; 李海鹰; 许心越

    2015-01-01

    瓶颈识别是城市轨道交通车站规划设计和运营管理亟待解决的难题。本文在既有静态瓶颈和动态瓶颈的基础上,按动态瓶颈产生原因将其细化为原发性瓶颈及继发性瓶颈;研究瓶颈的动态传播特性,提出关联瓶颈与瓶颈簇理论,以此刻画瓶颈传播机理,并在此基础上构建车站动态瓶颈识别方法;以瓶颈簇理论为支撑,定量分析单个设备能力对车站集散能力的影响程度,提出基于灵敏度分析的瓶颈疏解策略。最后,对北京地铁某车站进行案例分析,验证该瓶颈识别方法的有效性与实用性。案例表明,该方法能够有效识别车站瓶颈,明确瓶颈之间的依附关系以及瓶颈的重要程度。与既有方法相比减少66.7%的仿真次数,可以明显提高识别效率。%Bottleneck identification is an urgent issue that needs to be addressed in the planning,design and op-eration management of urban rail transit stations.Based on the concepts of existing static bottlenecks and dy-namic bottlenecks,dynamic bottlenecks were classified into two categories,i.e.primary bottlenecks and sec-ondary bottlenecks,according to the causes of dynamic bottlenecks.The dynamic bottleneck transmission characteristics were studied,and the correlation bottleneck and bottleneck cluster concepts were proposed to describe the bottleneck transmission mechanism,whereby a new bottleneck identification method was pro-posed.Supported by bottleneck cluster concept,quantitative analysis was conducted on the effect of the capaci-ty of an individual facility on collection and distribution capacity of the station,and sensitivity analysis-based bottleneck relief strategy was proposed.Finally,a case study of a station in Beijing subway was implemented to verify the validity and practicability of the proposed method.The results showed that this method can identi-fy the bottlenecks of a station effectively,and define the dependence

  12. A New Wireless Packet Scheduling Algorithm Based on EDF and Its Application in Multi-bottleneck Networks

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Most of current wireless packet scheduling algorithms aim at resource allocation as fairly as possible or maximizing throughput. This paper proposed a new packet scheduling algorithm that aims at satisfying delay requirement and is the improvement of earliest due first (EDF) algorithm in wired networks. The main idea is to classify the packets based on their delay bound, scheduling the most "urgent" class of user and the users that have the best channel condition with higher priority. This algorithm can easily integrate with common buffer management algorithms, when buffer management algorithm cannot accept new arrival packets, try to modify scheduling policy. Packet scheduling algorithms in multiple bottleneck wireless networks were also discussed. A new variable multi-hop factor was defined to estimate the congestion situation (including channel condition) of future hops.Multi-hop factor can be integrated into packet scheduling algorithms as assistant and supplement to improve its performance in multi-bottleneck wireless networks.

  13. Hurry Up and Wait: Differential Impacts of Congestion, Bottleneck Pressure, and Predictability on Patient Length of Stay

    OpenAIRE

    Berry Jaeker, Jillian Alexandra; Tucker, Anita Lynn

    2012-01-01

    High work load, from high inventory levels, impacts unit processing times, but prior operations management studies have found conflicting results regarding direction. Thus, it is difficult to predict inventory’s effects on productivity a priori, inhibiting effective capacity management in high load systems. We categorize load into in-process inventory (congestion) and incoming inventory, decomposing the latter into its levels of bottleneck (BN) pressure and predictability, and quantify the ma...

  14. Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus

    Science.gov (United States)

    Tully, Damien C.; Ogilvie, Colin B.; Batorsky, Rebecca E.; Bean, David J.; Power, Karen A.; Ghebremichael, Musie; Bedard, Hunter E.; Gladden, Adrianne D.; Seese, Aaron M.; Amero, Molly A.; Lane, Kimberly; McGrath, Graham; Bazner, Suzane B.; Tinsley, Jake; Lennon, Niall J.; Henn, Matthew R.; Brumme, Zabrina L.; Norris, Philip J.; Rosenberg, Eric S.; Mayer, Kenneth H.; Jessen, Heiko; Kosakovsky Pond, Sergei L.; Walker, Bruce D.; Altfeld, Marcus; Carlson, Jonathan M.; Allen, Todd M.

    2016-01-01

    Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM) exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX) transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU), we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic “signatures” within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission. PMID:27163788

  15. Oracle Database Common Bottleneck Issues Analysis%Oracle数据库常见的瓶颈问题分析

    Institute of Scientific and Technical Information of China (English)

    李文鹏

    2011-01-01

    Oracle database as the world's largest database companies at home and abroad has been applied widely.Article on the current Oracle database common bottleneck issues analyzed and discussed.%Oracle数据库作为全球第一大数据库厂商,在国内外获得了广泛应用。文章对目前Oracle数据库常见的瓶颈问题进行了分析探讨。

  16. Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus.

    Directory of Open Access Journals (Sweden)

    Damien C Tully

    2016-05-01

    Full Text Available Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU, we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic "signatures" within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission.

  17. Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus.

    Science.gov (United States)

    Tully, Damien C; Ogilvie, Colin B; Batorsky, Rebecca E; Bean, David J; Power, Karen A; Ghebremichael, Musie; Bedard, Hunter E; Gladden, Adrianne D; Seese, Aaron M; Amero, Molly A; Lane, Kimberly; McGrath, Graham; Bazner, Suzane B; Tinsley, Jake; Lennon, Niall J; Henn, Matthew R; Brumme, Zabrina L; Norris, Philip J; Rosenberg, Eric S; Mayer, Kenneth H; Jessen, Heiko; Kosakovsky Pond, Sergei L; Walker, Bruce D; Altfeld, Marcus; Carlson, Jonathan M; Allen, Todd M

    2016-05-01

    Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM) exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX) transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU), we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic "signatures" within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission. PMID:27163788

  18. Combinatorial Sec pathway analysis for improved heterologous protein secretion in Bacillus subtilis: identification of bottlenecks by systematic gene overexpression

    OpenAIRE

    Chen, Jingqi; Fu, Gang; Gai, Yuanming; Zheng, Ping; Zhang, Dawei; Wen, Jianping

    2015-01-01

    Background Secretory expression of valuable proteins by B. subtilis and its related species has attracted intensive work over the past three decades. Although very high yields can be achieved with homologous proteins, production of heterologous proteins by B. subtilis is unfortunately not the straight forward. The Sec pathway is the major route for protein secretion in B. subtilis. Therefore, the aim of this work was to identify the bottlenecks of the Sec pathway and improve the secretion of ...

  19. Transcriptome population genomics reveals severe bottleneck and domestication cost in the African rice (Oryza glaberrima).

    Science.gov (United States)

    Nabholz, Benoit; Sarah, Gautier; Sabot, François; Ruiz, Manuel; Adam, Hélène; Nidelet, Sabine; Ghesquière, Alain; Santoni, Sylvain; David, Jacques; Glémin, Sylvain

    2014-05-01

    The African cultivated rice (Oryza glaberrima) was domesticated in West Africa 3000 years ago. Although less cultivated than the Asian rice (O. sativa), O. glaberrima landraces often display interesting adaptation to rustic environment (e.g. drought). Here, using RNA-seq technology, we were able to compare more than 12,000 transcripts between 9 O. glaberrima, 10 wild O. barthii and one O. meridionalis individuals. With a synonymous nucleotide diversity πs = 0.0006 per site, O. glaberrima appears as the least genetically diverse crop grass ever documented. Using approximate Bayesian computation, we estimated that O. glaberrima experienced a severe bottleneck during domestication. This demographic scenario almost fully accounts for the pattern of genetic diversity across O. glaberrima genome as we detected very few outliers regions where positive selection may have further impacted genetic diversity. Moreover, the large excess of derived nonsynonymous substitution that we detected suggests that the O. glaberrima population suffered from the 'cost of domestication'. In addition, we used this genome-scale data set to demonstrate that (i) O. barthii genetic diversity is positively correlated with recombination rate and negatively with gene density, (ii) expression level is negatively correlated with evolutionary constraint, and (iii) one region on chromosome 5 (position 4-6 Mb) exhibits a clear signature of introgression with a yet unidentified Oryza species. This work represents the first genome-wide survey of the African rice genetic diversity and paves the way for further comparison between the African and the Asian rice, notably regarding the genetics underlying domestication traits.

  20. Thermodynamic modelling predicts energetic bottleneck for seabirds wintering in the northwest Atlantic.

    Science.gov (United States)

    Fort, Jérôme; Porter, Warren P; Grémillet, David

    2009-08-01

    Studying the energetics of marine top predators such as seabirds is essential to understand processes underlying adult winter survival and its impact on population dynamics. Winter survival is believed to be the single most important life-history trait in long-lived species but its determinants are largely unknown. Seabirds are inaccessible during this season, so conventional metabolic studies are extremely challenging and new approaches are needed. This paper describes and uses a state-of-the-art mechanistic model, Niche Mapper, to predict energy expenditure and food requirements of the two main seabird species wintering in the northwest Atlantic. We found that energy demand increased throughout the winter phase in both species. Across this period, mean estimated daily energy requirements were 1306 kJ day(-1) for Brünnich's guillemots (Uria lomvia) and 430 kJ day(-1) for little auks (Alle alle) wintering off Greenland and Newfoundland. Mean estimated daily food requirements were 547 g wet food day(-1) for Brünnich's guillemots, and 289 g wet food day(-1) for little auks. For both species and both wintering sites, our model predicts a sharp increase in energy expenditure between November and December, primarily driven by climatic factors such as air temperature and wind speed. These findings strongly suggest the existence of an energetic bottleneck for North Atlantic seabirds towards the end of the year, a challenging energetic phase which might explain recurrent events of winter mass-mortality, so called 'seabird winter wrecks'. Our study therefore emphasizes the relevance of thermodynamics/biophysical modelling for investigating the energy balance of wintering marine top predators and its interplay with survival and population dynamics in the context of global change. PMID:19617442

  1. IDENTIFYING BOTTLENECKS FOR APPROPRIATE INFANT FEEDING IN URBAN SLUMS, ALIGARH CITY.

    Directory of Open Access Journals (Sweden)

    Saira Mehnaz

    2012-04-01

    Full Text Available Introduction: Urban population is increasing rapidly. Majority of these families are poor or landless farmers and labourers, who settle down in peri-urban areas, creating slums. Urban slums are thus growing at an alarming rate. The present study was carried out with the general objective of identifying factors which prevent access to health services. Objectives: 1. To determine the prevalence of stunting, wasting, and underweight in infants and young children. 2. To determine presence of certain micro-environmental and socioeconomic factors associated with poor nutritional status of infants and children. Methodology: Baseline study was carried out in Oct –Nov 2009 (as a part of another ongoing study and data was collected in 110 Mothers who had delivered children during the last one month. In Oct 2010 these families were visited again the infants were followed up. 39 families had shifted to another location or emigrated back to their parent state or village mostly in search of seasonal employment as reported by neighbours. One family refused to cooperate. . Two infants had died. Remaining 68 Mothers were interviewed in friendly informal manner after taking consent for study. Results: (35.4% study subjects had migrated to other areas, as reported by neighbours. Of the 68 mothers interviewed during follow up visit, previous baseline record showed that a majority were 20-30 years of age. , only 2 mothers (2.9% had exclusively breastfed for 6 months. 46 (67.6% said they had not been contacted by any health worker during the last 3 months. All 68 children were malnourished. Immunization status was poor and 94.1% children had suffered from some illness in the last one month. Conclusion: Migration is a problem which makes it difficult for providers to give continuity of care. Capacity building of the community can reduce the the bottlenecks leading to marginalization and exclusion of slum mothers from the mainstream urban health services.

  2. Raptor mortality in wind farms of southern Spain: mitigation measures on a major migration bottleneck area

    Energy Technology Data Exchange (ETDEWEB)

    Gallego, Antonio-Roman Munoz; Lucas, Manuela De; Casado, Eva; Ferrer, Miguel

    2011-07-01

    Full text: To assess and monitor the impact of wind farms on fauna is crucial if we want to achieve ecologically sustainable development of this renewable energy resource. Today there are clear evidences that the probability of raptor collision depends critically on species behaviour and weather conditions, and the topographic factors related to each windmill. In our study area EIA were not able to predict this differential risk and in these circumstances mitigating the causes of bird mortality becomes a task of major importance, especially to those wind farms located in the Strait of Gibraltar, a water crossing of 14 km at its shortest distance acting as a major migration bottleneck for Paleo-African soaring migrants. We collected all available information on raptor collision from 1992, when the first wind farm was installed, and from 2005 until present a total of 262 turbines, grouped into 20 wind farms, were surveyed in a daily basis through a surveillance program with the main goal of register the actual mortality of birds. A total of 1291 raptors of 19 species were found of which 78.5% correspond to two species, the griffon vulture (Gyps fulvus) and the kestrel (Falco tinnunculus). In order to mitigate the impact on raptors, and particularly on the griffon vulture, in 2007 a program based on selective stopping of turbines was imposed, in collaboration with the environmental competent authority, on new approved projects. During 2008 there was a reduction in mortality by 48%, which remained in 2009 with a remarkably lower economic cost. An analysis of the temporal collision patterns will be presented and discussed, with special attention to those species suffering higher mortality rate, and to those who have some degree of threat. (Author)

  3. Population aging and migrant workers: bottlenecks in tuberculosis control in rural China.

    Directory of Open Access Journals (Sweden)

    Sumedh Bele

    Full Text Available BACKGROUND: Tuberculosis is a serious global health problem. Its paradigms are shifting through time, especially in rapidly developing countries such as China. Health providers in China are at the forefront of the battle against tuberculosis; however, there are few empirical studies on health providers' perspectives on the challenges they face in tuberculosis control at the county level in China. This study was conducted among health providers to explore their experiences with tuberculosis control in order to identify bottlenecks and emerging challenges in controlling tuberculosis in rural China. METHODS: A qualitative approach was used. Semi-structured, in-depth interviews were conducted with 17 health providers working in various positions within the health system of one rural county (ZJG of China. Data were analyzed based on thematic content analysis using MAXQDA 10 qualitative data analysis software. RESULTS: Health providers reported several problems in tuberculosis control in ZJG county. Migrant workers and the elderly were repeatedly documented as the main obstacles in effective tuberculosis control in the county. At a personal level, doctors showed their frustration with the lack of new drugs for treating tuberculosis patients, and their opinions varied regarding incentives for referring patients. CONCLUSION: The results suggest that several problems still remain for controlling tuberculosis in rural China. Tuberculosis control efforts need to make reaching the most vulnerable populations a priority and encourage local health providers to adopt innovative practices in the local context based on national guidelines to achieve the best results. Considerable changes in China's National Tuberculosis Control Program are needed to tackle these emerging challenges faced by health workers at the county level.

  4. Epigeic Earthworms Exert a Bottleneck Effect on Microbial Communities through Gut Associated Processes

    Science.gov (United States)

    Gómez-Brandón, María; Aira, Manuel; Lores, Marta; Domínguez, Jorge

    2011-01-01

    Background Earthworms play a critical role in organic matter decomposition because of the interactions they establish with microorganisms. The ingestion, digestion, assimilation of organic material in the gut and then casting is the first step in earthworm-microorganism interactions. The current knowledge of these direct effects is still limited for epigeic earthworm species, mainly those living in man-made environments. Here we tested whether and to what extent the earthworm Eisenia andrei is capable of altering the microbiological properties of fresh organic matter through gut associated processes; and if these direct effects are related to the earthworm diet. Methodology To address these questions we determined the microbial community structure (phospholipid fatty acid profiles) and microbial activity (fluorescein diacetate hydrolysis) in the earthworm casts derived from three types of animal manure (cow, horse and pig manure), which differed in microbial composition. Principal Findings The passage of the organic material through the gut of E. andrei reduced the total microbial biomass irrespective of the type of manure, and resulted in a decrease in bacterial biomass in all the manures; whilst leaving the fungi unaffected in the egested materials. However, unlike the microbial biomass, no such reduction was detected in the total microbial activity of cast samples derived from the pig manure. Moreover, no differences were found between cast samples derived from the different types of manure with regards to microbial community structure, which provides strong evidence for a bottleneck effect of worm digestion on microbial populations of the original material consumed. Conclusions/Significance Our data reveal that earthworm gut is a major shaper of microbial communities, thereby favouring the existence of a reduced but more active microbial population in the egested materials, which is of great importance to understand how biotic interactions within the decomposer

  5. Epigeic earthworms exert a bottleneck effect on microbial communities through gut associated processes.

    Directory of Open Access Journals (Sweden)

    María Gómez-Brandón

    Full Text Available BACKGROUND: Earthworms play a critical role in organic matter decomposition because of the interactions they establish with microorganisms. The ingestion, digestion, assimilation of organic material in the gut and then casting is the first step in earthworm-microorganism interactions. The current knowledge of these direct effects is still limited for epigeic earthworm species, mainly those living in man-made environments. Here we tested whether and to what extent the earthworm Eisenia andrei is capable of altering the microbiological properties of fresh organic matter through gut associated processes; and if these direct effects are related to the earthworm diet. METHODOLOGY: To address these questions we determined the microbial community structure (phospholipid fatty acid profiles and microbial activity (fluorescein diacetate hydrolysis in the earthworm casts derived from three types of animal manure (cow, horse and pig manure, which differed in microbial composition. PRINCIPAL FINDINGS: The passage of the organic material through the gut of E. andrei reduced the total microbial biomass irrespective of the type of manure, and resulted in a decrease in bacterial biomass in all the manures; whilst leaving the fungi unaffected in the egested materials. However, unlike the microbial biomass, no such reduction was detected in the total microbial activity of cast samples derived from the pig manure. Moreover, no differences were found between cast samples derived from the different types of manure with regards to microbial community structure, which provides strong evidence for a bottleneck effect of worm digestion on microbial populations of the original material consumed. CONCLUSIONS/SIGNIFICANCE: Our data reveal that earthworm gut is a major shaper of microbial communities, thereby favouring the existence of a reduced but more active microbial population in the egested materials, which is of great importance to understand how biotic interactions

  6. Analysis of talent bottleneck of chain retailing business%连锁零售企业人才瓶颈问题浅析

    Institute of Scientific and Technical Information of China (English)

    赵根良

    2012-01-01

    In the chain retailing business operation and management, talent is the foundation of its success and continuous development. With the rapid expansion of chain retailing business, chain retailing business in China has relatively serious talent bottleneck problem. Based on the analysis of the situation and reasons of Chinese chain retailing business talent bottleneck, this article puts forward counter- measures and suggestions to solve Chinese chain retailing business talent bottleneck problem.%在分析了我国连锁零售企业人才瓶颈的现状和原因的基础上,提出了解决这一问题的对策和建议。

  7. Variation at innate immunity Toll-like receptor genes in a bottlenecked population of a New Zealand robin.

    Directory of Open Access Journals (Sweden)

    Catherine E Grueber

    Full Text Available Toll-like receptors (TLRs are an ancient family of genes encoding transmembrane proteins that bind pathogen-specific molecules and initiate both innate and adaptive aspects of the immune response. Our goal was to determine whether these genes show sufficient genetic diversity in a bottlenecked population to be a useful addition or alternative to the more commonly employed major histocompatibility complex (MHC genotyping in a conservation genetics context. We amplified all known avian TLR genes in a severely bottlenecked population of New Zealand's Stewart Island robin (Petroica australis rakiura, for which reduced microsatellite diversity was previously observed. We genotyped 17-24 birds from a reintroduced island population (including the 12 founders for nine genes, seven of which were polymorphic. We observed a total of 24 single-nucleotide polymorphisms overall, 15 of which were non-synonymous, representing up to five amino-acid variants at a locus. One locus (TLR1LB showed evidence of past directional selection. Results also confirmed a passerine duplication of TLR7. The levels of TLR diversity that we observe are sufficient to justify their further use in addressing conservation genetic questions, even in bottlenecked populations.

  8. Contact transmission of influenza virus between ferrets imposes a looser bottleneck than respiratory droplet transmission allowing propagation of antiviral resistance.

    Science.gov (United States)

    Frise, Rebecca; Bradley, Konrad; van Doremalen, Neeltje; Galiano, Monica; Elderfield, Ruth A; Stilwell, Peter; Ashcroft, Jonathan W; Fernandez-Alonso, Mirian; Miah, Shahjahan; Lackenby, Angie; Roberts, Kim L; Donnelly, Christl A; Barclay, Wendy S

    2016-01-01

    Influenza viruses cause annual seasonal epidemics and occasional pandemics. It is important to elucidate the stringency of bottlenecks during transmission to shed light on mechanisms that underlie the evolution and propagation of antigenic drift, host range switching or drug resistance. The virus spreads between people by different routes, including through the air in droplets and aerosols, and by direct contact. By housing ferrets under different conditions, it is possible to mimic various routes of transmission. Here, we inoculated donor animals with a mixture of two viruses whose genomes differed by one or two reverse engineered synonymous mutations, and measured the transmission of the mixture to exposed sentinel animals. Transmission through the air imposed a tight bottleneck since most recipient animals became infected by only one virus. In contrast, a direct contact transmission chain propagated a mixture of viruses suggesting the dose transferred by this route was higher. From animals with a mixed infection of viruses that were resistant and sensitive to the antiviral drug oseltamivir, resistance was propagated through contact transmission but not by air. These data imply that transmission events with a looser bottleneck can propagate minority variants and may be an important route for influenza evolution. PMID:27430528

  9. A Qualitative Study of Bottlenecks and Causes of Fractions for Dedicated Incomes of Health Centers and Solutions for their Reduction

    Science.gov (United States)

    Tabrizi, Jafar Sadegh; Alidoost, Saeide; Abdolahi, Hossein Mashhadi

    2016-01-01

    Background: Primary health care is one of effective approaches for improving public health. Providing optimal cares requires supplication of various resources such as financial resources. “Fractions of incomes” in health centers is one of the remarkable problems for the domain of financial resources management in Iran. This study was aimed to identify bottlenecks and causes of fractions for incomes in health centers and solutions for their reduction. Methods: The current study was conducted in a qualitative phenomenology method in East Azerbaijan province of Iran in 2014. Data collection method was focus group discussion and semi-structured interview. Purposive sampling was used for selecting participants. Focus group discussions and interviews were conducted based on pre-prepared guidance and continued till data saturation. Validity of guidance was approved by qualitative studies experts. Data were analyzed using content analysis method. Results: Based on the opinions of participants, two and six themes were respectively extracted for bottlenecks of fractions and causes and solutions for their reduction. Themes for bottlenecks of fractions included cash (monetary) and non-cash (non-monetary) fractions and themes for causes and solutions included causes and solutions for fractions per capita, insurance deductions, fractions related to sending documents, registration fractions, discounts fractions, and incomplete deposit of cash incomes. Conclusion: All cash and non-cash incomes of health centers are subject to fractions. The causes of fractions are related to the whole process of converting services to incomes and insurance requirements. Identified solutions and interventions also focus on these areas.

  10. Childhood leukemia genetic bottleneck phenomenon related to TEL-AML1: the postulation by a mathematical model

    Institute of Scientific and Technical Information of China (English)

    Petar Ivanovski; Ivan Ivanovski; Dimitrije Nikoli(c); Ivana Jovanovi(c)

    2012-01-01

    Childhood leukemia bottleneck phenomenon is the most mysterious corollary of the prenatal origin discovery of leukemogenic chromosome translocations.The bottleneck is evidence that leukemia initiation,by in utero acquired chromosome translocations that generate functional fusion genes,is far more common than the incidence rate of corresponding leukemia.For childhood TEL-AML1+ acute lymphoblastic leukemia (ALL) this equates to approximately 100 times.Practically this means that among a hundred children born with TEL-AML1 fusion gene,only one child will later in its life develop ALL.The key data necessary for unraveling of this mystery were discovered in 2002.It was the level of TEL-AML1 + cells' frequency.The bottleneck is caused by the very low body TEL-AML1 + cell count.Only one out of a thousand B cells carries TEL-AML1 fusion gene.TEL-AML1+ body cell count is low because TEL-AML1 fusion is generated at cell level of 10a to 10-4 just during the late fetal lymphopoiesis i.e.after the 36th gestational week.

  11. Effect of Driver Behavior on Spatiotemporal Congested Traffic Patterns at Highway Bottlenecks in the Framework of Three-Phase Traffic Theory

    OpenAIRE

    Kerner, Boris S.

    2010-01-01

    We present results of numerical simulations of the effect of driver behavior on spatiotemporal congested traffic patterns that result from traffic breakdown at an on-ramp bottleneck. The simulations are made with the Kerner-Klenov stochastic traffic flow model in the framework of three-phase traffic theory. Different diagrams of congested patterns at the bottleneck associated with different driver behavioral characteristics are found and compared each other. An adaptive cruise control (ACC) i...

  12. Phonon bottleneck in GaAs/Al{sub x}Ga{sub 1−x}As quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y. C.; Robson, A. J.; Harrison, S.; Zhuang, Q. D.; Hayne, M., E-mail: m.hayne@lancaster.ac.uk [Department of Physics, Lancaster University, Lancaster, LA1 4YB (United Kingdom)

    2015-06-15

    We report low-temperature photoluminescence measurements on highly-uniform GaAs/Al{sub x}Ga{sub 1−x}As quantum dots grown by droplet epitaxy. Recombination between confined electrons and holes bound to carbon acceptors in the dots allow us to determine the energies of the confined states in the system, as confirmed by effective mass calculations. The presence of acceptor-bound holes in the quantum dots gives rise to a striking observation of the phonon-bottleneck effect.

  13. Resistance of virus to extinction on bottleneck passages: Study of a decaying and fluctuating pattern of fitness loss

    Science.gov (United States)

    Lázaro, Ester; Escarmís, Cristina; Pérez-Mercader, Juan; Manrubia, Susanna C.; Domingo, Esteban

    2003-01-01

    RNA viruses display high mutation rates and their populations replicate as dynamic and complex mutant distributions, termed viral quasispecies. Repeated genetic bottlenecks, which experimentally are carried out through serial plaque-to-plaque transfers of the virus, lead to fitness decrease (measured here as diminished capacity to produce infectious progeny). Here we report an analysis of fitness evolution of several low fitness foot-and-mouth disease virus clones subjected to 50 plaque-to-plaque transfers. Unexpectedly, fitness decrease, rather than being continuous and monotonic, displayed a fluctuating pattern, which was influenced by both the virus and the state of the host cell as shown by effects of recent cell passage history. The amplitude of the fluctuations increased as fitness decreased, resulting in a remarkable resistance of virus to extinction. Whereas the frequency distribution of fitness in control (independent) experiments follows a log-normal distribution, the probability of fitness values in the evolving bottlenecked populations fitted a Weibull distribution. We suggest that multiple functions of viral genomic RNA and its encoded proteins, subjected to high mutational pressure, interact with cellular components to produce this nontrivial, fluctuating pattern. PMID:12960384

  14. Optimization of pigment dyeing process of high performance fibers using feed-forward bottleneck neural networks mapping technique

    Energy Technology Data Exchange (ETDEWEB)

    Fjodorova, Natalja, E-mail: natalja.fjodorova@ki.si [National Institute of Chemistry, Hajdrihova 19, SI-1000, Ljubljana (Slovenia); Novic, Marjana [National Institute of Chemistry, Hajdrihova 19, SI-1000, Ljubljana (Slovenia); Diankova, Tamara [St-Petersburg State University of Technology and Design, Bolshaya Morskaya st. 18, 191186, St. Petersburg (Russian Federation)

    2011-10-31

    Highlights: {yields} Optimum conditions of pigment dying process of high performance fibers were proposed. {yields} The feed-forward bottleneck neural network (FFBN) as a mapping technique was implemented. {yields} We showed the influence of different factors (parameters of pigment dying) on different output responses (quality of pigment dying). - Abstract: Process optimization involves the minimization (or maximization) of an objective function, that can be established from a technical and (or) economic viewpoint taking into account safety of process. The basic idea of the optimization method using neural network (NN) is to replace the model equations (which traditionally obtained using, for example, the surface response design or others methods) by an equivalent NN. The feed-forward bottleneck neural network (FFBN) as a mapping technique is described and evaluated. From the 2D maps the optimal parameters of pigment dyeing of high performance fibers on the bases of poly-amide benzimidazole (PABI) and polyimide (arimid) are discussed. The studied fibers were treated in 32 experiments under the conditions as proposed by the Design of Experiment (DOE), varying five influencing factors. Neural network mapping method enables visualization of process and shows the influence of different factors on different output responses. Optimum parameters were selected upon compromise decision.

  15. Is integration and survival of newborn neurons the bottleneck for effective neural repair by endogenous neural precursor cells?

    Directory of Open Access Journals (Sweden)

    Ann eTurnley

    2014-02-01

    Full Text Available After two decades of research the existence of adult neural precursor cells and the phenomenon of adult neurogenesis is well established. However, there has been little or no effective harnessing of these endogenous cells to promote functional neuronal replacement following neural injury or disease. Neural precursor cells can respond to neural damage by proliferating, migrating to the site of injury and differentiating into neuronal or glial lineages. However, after a month or so, very few or no newborn neurons can be detected, suggesting that even though neuroblasts are generated, they generally fail to survive as mature neurons and contribute to the local circuitry. Is this lack of survival and integration one of the major bottlenecks that inhibits effective neuronal replacement and subsequent repair of the nervous system following injury or disease? In this perspective article the possibility that this bottleneck can be targeted to enhance the integration and subsequent survival of newborn neurons will be explored and will suggest some possible mechanisms that may need to be modulated for this to occur.

  16. Optimization of pigment dyeing process of high performance fibers using feed-forward bottleneck neural networks mapping technique

    International Nuclear Information System (INIS)

    Highlights: → Optimum conditions of pigment dying process of high performance fibers were proposed. → The feed-forward bottleneck neural network (FFBN) as a mapping technique was implemented. → We showed the influence of different factors (parameters of pigment dying) on different output responses (quality of pigment dying). - Abstract: Process optimization involves the minimization (or maximization) of an objective function, that can be established from a technical and (or) economic viewpoint taking into account safety of process. The basic idea of the optimization method using neural network (NN) is to replace the model equations (which traditionally obtained using, for example, the surface response design or others methods) by an equivalent NN. The feed-forward bottleneck neural network (FFBN) as a mapping technique is described and evaluated. From the 2D maps the optimal parameters of pigment dyeing of high performance fibers on the bases of poly-amide benzimidazole (PABI) and polyimide (arimid) are discussed. The studied fibers were treated in 32 experiments under the conditions as proposed by the Design of Experiment (DOE), varying five influencing factors. Neural network mapping method enables visualization of process and shows the influence of different factors on different output responses. Optimum parameters were selected upon compromise decision.

  17. Bottlenecks in deriving definitive hematopoietic stem cells from human pluripotent stem cells: a CIRM mini-symposium and workshop report.

    Science.gov (United States)

    Shepard, Kelly A; Talib, Sohel

    2014-07-01

    On August 29, 2013, the California Institute for Regenerative Medicine (CIRM) convened a small group of investigators in San Francisco, CA, to discuss a longstanding challenge in the stem cell field: the inability to derive fully functional, definitive hematopoietic stem cells (HSCs) from pluripotent stem cells (PSCs). To date, PSC-derived HSCs have been deficient in their developmental potential and their ability to self-renew and engraft upon transplantation. Tasked with identifying key challenges to overcoming this "HSC bottleneck", workshop participants identified critical knowledge gaps in two key areas: (a) understanding the ontogeny of human HSCs, and (b) understanding of the intrinsic and extrinsic factors that govern HSC behavior and function. They agreed that development of new methods and tools is critical for addressing these knowledge gaps. These include molecular profiling of key HSC properties, development of new model systems/assays for predicting and assessing HSC function, and novel technological advancements for manipulating cell culture conditions and genetic programs. The workshop produced tangible advances, including providing a current definition of the nature and challenge of the HSC bottleneck and identifying key mechanistic studies of HSC biology that should be prioritized for future funding initiatives (e.g., including higher risk approaches that have potential for high gain). PMID:24973044

  18. Differences in Strength and Timing of the mtDNA Bottleneck between Zebrafish Germline and Non-germline Cells

    Directory of Open Access Journals (Sweden)

    Auke B.C. Otten

    2016-07-01

    Full Text Available We studied the mtDNA bottleneck in zebrafish to elucidate size, timing, and variation in germline and non-germline cells. Mature zebrafish oocytes contain, on average, 19.0 × 106 mtDNA molecules with high variation between oocytes. During embryogenesis, the mtDNA copy number decreases to ∼170 mtDNA molecules per primordial germ cell (PGC, a number similar to that in mammals, and to ∼50 per non-PGC. These occur at the same developmental stage, implying considerable variation in mtDNA copy number in (non-PGCs of the same female, dictated by variation in the mature oocyte. The presence of oocytes with low mtDNA numbers, if similar in humans, could explain how (de novo mutations can reach high mutation loads within a single generation. High mtDNA copy numbers in mature oocytes are established by mtDNA replication during oocyte development. Bottleneck differences between germline and non-germline cells, due to early differentiation of PGCs, may account for different distribution patterns of familial mutations.

  19. Conservation genetics of the alligator snapping turtle: cytonuclear evidence of range-wide bottleneck effects and unusually pronounced geographic structure

    Science.gov (United States)

    Echelle, A.A.; Hackler, J.C.; Lack, Justin B.; Ballard, S. R.; Roman, J.; Fox, S. F.; Leslie,, David M., Jr.; Van Den Bussche, Ronald A.

    2010-01-01

    A previous mtDNA study indicated that female-mediated gene flow was extremely rare among alligator snapping turtle populations in different drainages of the Gulf of Mexico. In this study, we used variation at seven microsatellite DNA loci to assess the possibility of male-mediated gene flow, we augmented the mtDNA survey with additional sampling of the large Mississippi River System, and we evaluated the hypothesis that the consistently low within-population mtDNA diversity reflects past population bottlenecks. The results show that dispersal between drainages of the Gulf of Mexico is rare (F STmsat  = 0.43, ΦSTmtDNA = 0.98). Past range-wide bottlenecks are indicated by several genetic signals, including low diversity for microsatellites (1.1–3.9 alleles/locus; H e = 0.06–0.53) and mtDNA (h = 0.00 for most drainages; π = 0.000–0.001). Microsatellite data reinforce the conclusion from mtDNA that the Suwannee River population might eventually be recognized as a distinct taxonomic unit. It was the only population showing fixation or near fixation for otherwise rare microsatellite alleles. Six evolutionarily significant units are recommended on the basis of reciprocal mtDNA monophyly and high levels of microsatellite DNA divergence.

  20. The Effects of Juvenile Competitive Bottleneck on Dynamic Behavior%幼年竞争瓶颈对动力学行为的影响

    Institute of Scientific and Technical Information of China (English)

    唐光耀

    2011-01-01

    The effect of juvenile competitive bottlenecks on population dynamics is investigated by formulating food web models with a nonlinear maturation rate.The food web system consists of a resource (R),an intermediate consumer (N) and a predator (P).Our results show,with weak bottlenecks,that a juvenile bottleneck in the predator's life history has a larger impact than a bottleneck in the consumer.In the food web model with bottleneck for the predator,there are two possible internal steady states,and the system can exhibit consumer-predator equilibrium and consumer equilibrium as two alternative stable states,as well as the consumer equilibrium and predator equilibrium as two alternative stable states.No bistable phenomenon induced by bottleneck can be detected,and nothing new happens in system with consumer bottlenecks.Further,we show that a bottleneck can change the net effect of the intermediate consumer on predator from facilitation to inhibition or from inhibition to facilitation,which case occurs depends on both the choice of bottleneck and the initial states of systems.%通过建立具有非线性成熟率的食物网模型研究了幼年竞争瓶颈对种群动力学行为的影响,结论显示当竞争瓶颈比较弱的时,捕食者生活史中的幼年瓶颈对系统的影响要大于成年.模型存在两种可能的共存态或双稳定性,即消费者-捕食者和消费者平衡态共存,但是瓶颈不能诱导系统的双稳定性.进一步研究说明了选择不同的瓶颈或初始条件,瓶颈能够改变次级消费者对捕食者的净影响.

  1. 作业车间区间型多属性瓶颈识别方法%Interval multi-attribute bottleneck identification in job shop

    Institute of Scientific and Technical Information of China (English)

    王军强; 陈剑; 王烁; 郭银洲; 张映锋; 孙树栋

    2013-01-01

    Aiming at the Job shop bottleneck identification problem under random disturbance resulting in the difficulty of obtaining the determinate value of machine feature attribute, interval form was used to describe these uncertain attributes of machine. Furthermore, a new interval multi-attribute bottleneck identification model was established, and an interval TOPSIS bottleneck identification approach was proposed. By considering the close relationship between bottleneck utilization and bottleneck identification, an integrated framework, under which they could be solved simultaneously, was presented. This framework included two layers. In the first layer of bottleneck utilization, the Plant-Simulation platform was used to simulate random disturbance including equipment failure. Genetic algorithm (GA) was applied to perform optimization and simulation for the scheduling problems under the random disturbance and the optimum scheduling solution was obtained. In the second layer of bottleneck identification, based on scheduling optimization, interval TOPSIS bottleneck identification approach was proposed to identify bottleneck machines with considerations of multiple feature attributes. Comparing the proposed approach with machine utilization, bottleneck occurrence rate and shifting bottleneck detection method in the existing literatures, the results demonstrated the effectiveness of this approach. Finally, the influence of machining cost and material cost on bottleneck identification was analyzed.%针对扰动情形下作业车间瓶颈识别时机器的特征属性难以用确定值表示的问题,采用区间形式描述机器特征属性,构建了区间型多属性瓶颈识别模型,提出了区间TOPSIS多属性瓶颈识别方法.考虑瓶颈识别与瓶颈利用的紧密关系,提出了先进行瓶颈利用再进行瓶颈识别的统一框架.其中瓶颈利用层基于Plant-Simulation 仿真平台设置了机器故障等随机扰动,采用遗传算法对扰动情形

  2. Blue Cathodoluminescence from Highly Er-Doped ZnO Thin Films Induced by the Phonon Bottleneck Effect

    Institute of Scientific and Technical Information of China (English)

    张喜田; 刘益春; 马剑刚; 吕有明; 申德振; 许武; 钟国柱; 范希武

    2003-01-01

    The room-temperature blue cathodoluminescence (CL) from highly Er-doped ZnO thin films has been studied by using different electron beam currents (EBCs). The ZnO:Er thin films used in our experiment were prepared by simultaneous evaporation from two sources. The x-ray diffraction spectra show that the thin films have a strong preferential c-axis (0002) orientation with a hexagonal crystalline structure. The blue emission at 455 nm originating from the intra-4 f shell transition (4F5/2.4I15/2) in Er3+ ions was observed at room temperature. The nonlinear dependence of the CL intensity on the EBC shows a more intense blue emission above the threshold EBC of 0. 6 μA, which is attributed to the phonon bottleneck effect.

  3. Limited population structure, genetic drift and bottlenecks characterise an endangered bird species in a dynamic, fire-prone ecosystem.

    Directory of Open Access Journals (Sweden)

    Sarah M Brown

    Full Text Available Fire is a major disturbance process in many ecosystems world-wide, resulting in spatially and temporally dynamic landscapes. For populations occupying such environments, fire-induced landscape change is likely to influence population processes, and genetic patterns and structure among populations. The Mallee Emu-wren Stipiturus mallee is an endangered passerine whose global distribution is confined to fire-prone, semi-arid mallee shrublands in south-eastern Australia. This species, with poor capacity for dispersal, has undergone a precipitous reduction in distribution and numbers in recent decades. We used genetic analyses of 11 length-variable, nuclear loci to examine population structure and processes within this species, across its global range. Populations of the Mallee Emu-wren exhibited a low to moderate level of genetic diversity, and evidence of bottlenecks and genetic drift. Bayesian clustering methods revealed weak genetic population structure across the species' range. The direct effects of large fires, together with associated changes in the spatial and temporal patterns of suitable habitat, have the potential to cause population bottlenecks, serial local extinctions and subsequent recolonisation, all of which may interact to erode and homogenise genetic diversity in this species. Movement among temporally and spatially shifting habitat, appears to maintain long-term genetic connectivity. A plausible explanation for the observed genetic patterns is that, following extensive fires, recolonisation exceeds in-situ survival as the primary driver of population recovery in this species. These findings suggest that dynamic, fire-dominated landscapes can drive genetic homogenisation of populations of species with low-mobility and specialised habitat that otherwise would be expected to show strongly structured populations. Such effects must be considered when formulating management actions to conserve species in fire-prone systems.

  4. Narrow bottlenecks affect Pea seedborne mosaic virus populations during vertical seed transmission but not during leaf colonization.

    Directory of Open Access Journals (Sweden)

    Frédéric Fabre

    2014-01-01

    Full Text Available The effective size of populations (Ne determines whether selection or genetic drift is the predominant force shaping their genetic structure and evolution. Populations having high Ne adapt faster, as selection acts more intensely, than populations having low Ne, where random effects of genetic drift dominate. Estimating Ne for various steps of plant virus life cycle has been the focus of several studies in the last decade, but no estimates are available for the vertical transmission of plant viruses, although virus seed transmission is economically significant in at least 18% of plant viruses in at least one plant species. Here we study the co-dynamics of two variants of Pea seedborne mosaic virus (PSbMV colonizing leaves of pea plants (Pisum sativum L. during the whole flowering period, and their subsequent transmission to plant progeny through seeds. Whereas classical estimators of Ne could be used for leaf infection at the systemic level, as virus variants were equally competitive, dedicated stochastic models were needed to estimate Ne during vertical transmission. Very little genetic drift was observed during the infection of apical leaves, with Ne values ranging from 59 to 216. In contrast, a very drastic genetic drift was observed during vertical transmission, with an average number of infectious virus particles contributing to the infection of a seedling from an infected mother plant close to one. A simple model of vertical transmission, assuming a cumulative action of virus infectious particles and a virus density threshold required for vertical transmission to occur fitted the experimental data very satisfactorily. This study reveals that vertically-transmitted viruses endure bottlenecks as narrow as those imposed by horizontal transmission. These bottlenecks are likely to slow down virus adaptation and could decrease virus fitness and virulence.

  5. Analysis of Object and Bottle-Necks for Chemical Plant Retrofit%化工装置扩建改造的目标与瓶颈分析

    Institute of Scientific and Technical Information of China (English)

    胡仰栋; 李玉刚; 韩方煜

    2001-01-01

    对化工装置扩建改造的目标与瓶颈进行了分析,阐述了目标与瓶颈在扩建改造过程中的相辅相成关系。给出了制定目标和发现瓶颈的一般原则,认为发现并去除瓶颈的顺序应该是先考虑信息瓶颈,然后考虑强度瓶颈,最后再考虑容积瓶颈。结合实例给出了目标与瓶颈分析在扩建改造中的应用。%Object and bottle-necks were analyzed for chemical plant retrofit.The relationship between object and bottle-necks in the process of plant expansion and revamping was related.A general rule to establish object and to find bottle-necks was given,which suggests that the sequence to find bottle-necks should be informational factors,intensive factors and extensive factors.An example was given to show the application of methods mentioned above in chemical plant retrofit.

  6. Microsatellite analysis of a population crash and bottleneck in the Mauna Kea silversword, Argyroxiphium sandwicense ssp. sandwicense (Asteraceae), and its implications for reintroduction.

    Science.gov (United States)

    Friar, E A; Ladoux, T; Roalson, E H; Robichaux, R H

    2000-12-01

    The Mauna Kea silversword, Argyroxiphium sandwicense ssp. sandwicense, has experienced both a severe population crash associated with an increase in alien ungulate populations on Mauna Kea, and a population bottleneck associated with reintroduction. In this paper, we address the genetic consequences of both demographic events using eight microsatellite loci. The population crash was not accompanied by a significant reduction in number of alleles or heterozygosity. However, the population bottleneck was accompanied by significant reductions in observed number of alleles, effective number of alleles, and expected heterozygosity, though not in observed heterozygosity. The effective size of the population bottleneck was calculated using both observed heterozygosities and allele frequency variances. Both methods corroborated the historical census size of the population bottleneck of at most three individuals. The results suggest that: (i) small populations, even those that result from severe reductions in historical population size and extent, are not necessarily genetically depauperate; and (ii) species reintroduction plans need to be conceived and implemented carefully, with due consideration to the genetic impact of sampling for reintroduction.

  7. Microscopic theory of traffic-flow instability governing traffic breakdown at highway bottlenecks: Growing wave of increase in speed in synchronized flow.

    Science.gov (United States)

    Kerner, Boris S

    2015-12-01

    We have revealed a growing local speed wave of increase in speed that can randomly occur in synchronized flow (S) at a highway bottleneck. The development of such a traffic flow instability leads to free flow (F) at the bottleneck; therefore, we call this instability an S→F instability. Whereas the S→F instability leads to a local increase in speed (growing acceleration wave), in contrast, the classical traffic flow instability introduced in the 1950s-1960s and incorporated later in a huge number of traffic flow models leads to a growing wave of a local decrease in speed (growing deceleration wave). We have found that the S→F instability can occur only if there is a finite time delay in driver overacceleration. The initial speed disturbance of increase in speed (called "speed peak") that initiates the S→F instability occurs usually at the downstream front of synchronized flow at the bottleneck. There can be many speed peaks with random amplitudes that occur randomly over time. It has been found that the S→F instability exhibits a nucleation nature: Only when a speed peak amplitude is large enough can the S→F instability occur; in contrast, speed peaks of smaller amplitudes cause dissolving speed waves of a local increase in speed (dissolving acceleration waves) in synchronized flow. We have found that the S→F instability governs traffic breakdown-a phase transition from free flow to synchronized flow (F→S transition) at the bottleneck: The nucleation nature of the S→F instability explains the metastability of free flow with respect to an F→S transition at the bottleneck. PMID:26764764

  8. Microscopic theory of traffic-flow instability governing traffic breakdown at highway bottlenecks: Growing wave of increase in speed in synchronized flow.

    Science.gov (United States)

    Kerner, Boris S

    2015-12-01

    We have revealed a growing local speed wave of increase in speed that can randomly occur in synchronized flow (S) at a highway bottleneck. The development of such a traffic flow instability leads to free flow (F) at the bottleneck; therefore, we call this instability an S→F instability. Whereas the S→F instability leads to a local increase in speed (growing acceleration wave), in contrast, the classical traffic flow instability introduced in the 1950s-1960s and incorporated later in a huge number of traffic flow models leads to a growing wave of a local decrease in speed (growing deceleration wave). We have found that the S→F instability can occur only if there is a finite time delay in driver overacceleration. The initial speed disturbance of increase in speed (called "speed peak") that initiates the S→F instability occurs usually at the downstream front of synchronized flow at the bottleneck. There can be many speed peaks with random amplitudes that occur randomly over time. It has been found that the S→F instability exhibits a nucleation nature: Only when a speed peak amplitude is large enough can the S→F instability occur; in contrast, speed peaks of smaller amplitudes cause dissolving speed waves of a local increase in speed (dissolving acceleration waves) in synchronized flow. We have found that the S→F instability governs traffic breakdown-a phase transition from free flow to synchronized flow (F→S transition) at the bottleneck: The nucleation nature of the S→F instability explains the metastability of free flow with respect to an F→S transition at the bottleneck.

  9. Bottleneck Analysis of the Minimum Cost Problem for the Generalized Network Based on Augmented Forest Structure%基于增广森林结构的一般网络最小费用问题瓶颈分析

    Institute of Scientific and Technical Information of China (English)

    江永亨; 王军; 金以慧

    2003-01-01

    The bottleneck analysis of the minimum cost problem for the generalized network (MCPGN) is dis-cussed. The analysis is based on the network simplex algorithm, which gains negative cost graphs by constructingaugmented forest structure, then augments flows on the negative cost graphs until the optimal revolution is gained.Bottleneck structure is presented after analyzing the augmented forest structure. The negative cost augmentedgraphs are constructed with the bottleneck structure. The arcs that block the negative cost augmented graph arethe elements of the bottleneck. The bottleneck analysis for the generalized circulation problem, the minimum circu-lation problem and the circulation problem are discussed respectively as the basal problems, then that for MCPGNis achieved. An example is presented at the end.

  10. Consequences of extreme life history traits on population persistence: do short-lived gobies face demographic bottlenecks?

    Science.gov (United States)

    Lefèvre, Carine D.; Nash, Kirsty L.; González-Cabello, Alonso; Bellwood, David R.

    2016-06-01

    The majority of coral reef goby species are short-lived, with some highly abundant species living less than 100 d. To understand the role and consequences of this extreme life history in shaping coral reef fish populations, we quantitatively documented the structure of small reef fish populations over a 26-month period (>14 short-lived fish generations) at an inshore reef on the Great Barrier Reef, Australia. Most species with life spans >1 yr, such as pomacentrids, exhibited a peak in recruitment during the austral summer, driving seasonal changes in the small fish community composition. In contrast, there were no clear changes in goby community composition, despite the abundance of short-lived, high turnover species. Species of Eviota, the most abundant gobiid genus observed, showed remarkably similar demographic profiles year-round, with consistent densities of adults as well as recently recruited juveniles. Our results demonstrate ongoing recruitment of these small cryptic fishes, which appears to compensate for an exceptionally short life span on the reef. Our results suggest that gobiid populations are able to overcome demographic limitations, and by maintaining reproduction, larval survival and recruitment throughout the year, they may avoid population bottlenecks. These findings also underline the potential trophodynamic importance of these small species; because of this constant turnover, Eviota species and other short-lived fishes may be particularly valuable contributors to the flow of energy on coral reefs, underpinning the year-round trophic structure.

  11. Breaking the I/O bottleneck for high-compute performance processing with Xtensa LX configurable and extensible processor architecture

    Science.gov (United States)

    Ezer, Gulbin A.

    2005-03-01

    The challenges of new embedded applications have conflicting requirements: complex algorithms, evolving standards, shorter product cycles dictate programmable solutions, and yet, high data bandwidth, compute power and lower power consumption dictate carefully crafted hardwired functional modules. An application specific instruction set processor (ASIP) is ideally suited to provide most of the advantages of hardwired logic, while maintaining the time-to-market and programmability advantages of a general purpose processor. This paper presents the unique blend of high compute performance and i/o bandwidth of the configurable and extensible Xtensa LX ASIP architectures. Xtensa LX provides high compute performance with wide instruction words using multiple operation slots that enable superscalar performance suitable for data-intensive applications. Xtensa LX also provides high I/O bandwidth through its multiple load/store units that provide parallel low latency access or external DMA access to local memories and virtually unlimited number of ports and queues directly connected to the processor core functional units and system control registers, which remove the I/O bottleneck of traditional processors. The advantages of Xtensa LX features are proven with their impressive performance results: 171.6 ConsumerMark on out-of-the-box simulation of EEMBC consumer suite and a BDTIsimMark2000™ score of 6150 at 370MHz.

  12. The role of host and microbial factors in the pathogenesis of pneumococcal bacteraemia arising from a single bacterial cell bottleneck.

    Directory of Open Access Journals (Sweden)

    Alice Gerlini

    2014-03-01

    Full Text Available The pathogenesis of bacteraemia after challenge with one million pneumococci of three isogenic variants was investigated. Sequential analyses of blood samples indicated that most episodes of bacteraemia were monoclonal events providing compelling evidence for a single bacterial cell bottleneck at the origin of invasive disease. With respect to host determinants, results identified novel properties of splenic macrophages and a role for neutrophils in early clearance of pneumococci. Concerning microbial factors, whole genome sequencing provided genetic evidence for the clonal origin of the bacteraemia and identified SNPs in distinct sub-units of F0/F1 ATPase in the majority of the ex vivo isolates. When compared to parental organisms of the inoculum, ex-vivo pneumococci with mutant alleles of the F0/F1 ATPase had acquired the capacity to grow at low pH at the cost of the capacity to grow at high pH. Although founded by a single cell, the genotypes of pneumococci in septicaemic mice indicate strong selective pressure for fitness, emphasising the within-host complexity of the pathogenesis of invasive disease.

  13. Genetic Evidence of a Population Bottleneck and Inbreeding in the Endangered New Zealand Sea Lion, Phocarctos hookeri.

    Science.gov (United States)

    Osborne, Amy J; Negro, Sandra S; Chilvers, B Louise; Robertson, Bruce C; Kennedy, Martin A; Gemmell, Neil J

    2016-09-01

    The New Zealand sea lion (NZSL) is of high conservation concern due to its limited distribution and its declining population size. Historically, it occupied most of coastal New Zealand, but is now restricted to a few coastal sites in southern mainland New Zealand and the sub-Antarctic Islands. NZSLs have experienced a recent reduction in population size due to sealing in the 1900s, which is expected to have resulted in increased inbreeding and a loss of genetic variation, potentially reducing the evolutionary capacity of the species and negatively impacting on its long-term prospects for survival. We used 17 microsatellite loci, previously shown to have cross-species applications in pinnipeds, to determine locus- and population-specific statistics for 1205 NZSLs from 7 consecutive breeding seasons. We show that the NZSL population has a moderate level of genetic diversity in comparison to other pinnipeds. We provide genetic evidence for a population reduction, likely caused by historical sealing, and a measure of allele sharing/parental relatedness (internal relatedness) that is suggestive of increased inbreeding in pups that died during recent epizootic episodes. We hypothesize that population bottlenecks and nonrandom mating have impacted on the population genetic architecture of NZSLs, affecting its population recovery. PMID:26995741

  14. 我国北极通航瓶颈问题分析%Analysis on Arctic shipping bottlenecks for China

    Institute of Scientific and Technical Information of China (English)

    曹玉墀; 刘大刚; 刘军坡

    2012-01-01

      As a result of the global warming,the issues concerning Arctic navigation have drawn increasing attention in the world.However,navigation in the Arctic waters depends on the clear understanding of difficulties and problems.This paper,from the perspective of legislation,marine environment protection,ships and navigation conditions,seafarer training and certification,provides a primary analysis on some bottleneck issues concerning involvement of China in Arctic shipping,for reference by those people engaged in the research of Arctic shipping.%  随着全球气温变暖趋势的显现,北极通航问题日益受到各方面的关注。但是要实施北极通航,必须对可能面临的困难和问题有清楚的认识。文中从法律法规、环境保护、船舶和航行条件,以及船员培训和认证等方面,对中国实施北极通航可能存在的一些瓶颈问题作了初步分析,可为从事北极通航问题研究人员提供参考。

  15. LONG-ORBITAL-PERIOD PREPOLARS CONTAINING EARLY K-TYPE DONOR STARS. BOTTLENECK ACCRETION MECHANISM IN ACTION

    Energy Technology Data Exchange (ETDEWEB)

    Tovmassian, G.; González–Buitrago, D.; Zharikov, S. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Apartado Postal 877, Ensenada, Baja California, 22800 México (Mexico); Reichart, D. E.; Haislip, J. B.; Ivarsen, K. M.; LaCluyze, A. P.; Moore, J. P. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Campus Box 3255, Chapel Hill, NC 27599 (United States); Miroshnichenko, A. S., E-mail: gag@astro.unam.mx, E-mail: dgonzalez@astro.unam.mx, E-mail: zhar@astro.unam.mx [Department of Physics and Astronomy, University of North Carolina at Greensboro, Greensboro, NC 27402-6170 (United States)

    2016-03-01

    We studied two objects identified as cataclysmic variables (CVs) with periods exceeding the natural boundary for Roche-lobe-filling zero-age main sequence (ZAMS) secondary stars. We present observational results for V1082 Sgr with a 20.82 hr orbital period, an object that shows a low luminosity state when its flux is totally dominated by a chromospherically active K star with no signs of ongoing accretion. Frequent accretion shutoffs, together with characteristics of emission lines in a high state, indicate that this binary system is probably detached, and the accretion of matter on the magnetic white dwarf takes place through stellar wind from the active donor star via coupled magnetic fields. Its observational characteristics are surprisingly similar to V479 And, a 14.5 hr binary system. They both have early K-type stars as donor stars. We argue that, similar to the shorter-period prepolars containing M dwarfs, these are detached binaries with strong magnetic components. Their magnetic fields are coupled, allowing enhanced stellar wind from the K star to be captured and channeled through the bottleneck connecting the two stars onto the white dwarf’s magnetic pole, mimicking a magnetic CV. Hence, they become interactive binaries before they reach contact. This will help to explain an unexpected lack of systems possessing white dwarfs with strong magnetic fields among detached white+red dwarf systems.

  16. Juvenile competitive bottleneck in the production of brown trout in hydroelectric reservoirs due to intraspecific habitat segregation

    International Nuclear Information System (INIS)

    Resource utilization and growth of brown trout were studied in four deep (mean depths 16.2 - 37.5 m) Norwegian hydroelectric reservoirs by benthic and pelagic gillnet sampling. In all the reservoirs supplementary stockings are carried out. The brown trout were spatially segregated according to size as the habitat use of small individuals (< 180-220 mm) was completely restricted to benthic habitats, whereas larger individuals mainly utilized the upper strata of pelagic waters. It is argued that the pelagic habitat is the more rewarding, and that small-sized brown trout are forced into the less favourable benthic habitat through social interactions with larger specimens. This is supported by an increase in growth of brown trout from their third to fifth year of life, which seems to be related to the shift from benthic to pelagic behaviour. It is also argued that the conditions for small-sized brown trout may be a bottleneck in the capacity to produce brown trout in hydroelectric reservoirs with limited benthic feeding conditions, despite ample access to food in pelagic habitats. When evaluating the possibility of increasing the yield of brown trout through supplementary stockings, it is therefore important to consider food and growth conditions for all age and size groups of brown trout. In reservoirs with poor benthic feeding conditions it may be necessary to stock with brown trout of sizes that are large enough to utilize pelagic habitat, to avoid the limiting benthic living stage. (Author)

  17. Genetic variability in four Alouatta species measured by means of nine DNA microsatellite markers: genetic structure and recent bottlenecks.

    Science.gov (United States)

    Ruiz-Garcia, M; Escobar-Armel, P; Alvarez, D; Mudry, M; Ascunce, M; Gutierrez-Espeleta, G; Shostell, J M

    2007-01-01

    We used microsatellite DNA to study the population genetics of 4 Alouatta species from Central and South America. Our main findings include the following: (1) A. seniculus had the highest level of microsatellite variability while A. caraya and A. palliata had the lowest mean number of alleles per locus and the lowest expected heterozygosity, respectively; (2) the samples of A. seniculus and A. palliata came from different regions and were not in Hardy-Weinberg equilibrium (HWE) which may indicate a Wahlund effect and differentiated gene pools -- in contrast, A. macconnelli and A. caraya were in HWE; (3) the microsatellite genetic heterogeneity of the 4 Alouatta species was similar to the karyotype divergence found among these Alouatta species; the species pair with the lowest level of heterogeneity (genetic differentiation) was A. seniculus/A. caraya, while the Central American species, A. palliata, was highly differentiated from the other 3 South American species; (4) we recommend the establishment of a conservation plan to help protect A. caraya because the Cornuet and Luikart procedure demonstrated a recent bottleneck for this species. PMID:17303937

  18. Ancient DNA reveals substantial genetic diversity in the California Condor (Gymnogyps californianus) prior to a population bottleneck

    Science.gov (United States)

    D'Elia, Jesse; Haig, Susan M.; Mullins, Thomas D.; Miller, Mark P.

    2016-01-01

    Critically endangered species that have undergone severe population bottlenecks often have little remaining genetic variation, making it difficult to reconstruct population histories to apply in reintroduction and recovery strategies. By using ancient DNA techniques, it is possible to combine genetic evidence from the historical population with contemporary samples to provide a more complete picture of a species' genetic variation across its historical range and through time. Applying this approach, we examined changes in the mitochondrial DNA (mtDNA) control region (526 base pairs) of the endangered California Condor (Gymnogyps californianus). Results showed a >80% reduction in unique haplotypes over the past 2 centuries. We found no spatial sorting of haplotypes in the historical population; the periphery of the range contained haplotypes that were common throughout the historical range. Direct examination of mtDNA from California Condor museum specimens provided a new window into historical population connectivity and genetic diversity showing: (1) a substantial loss of haplotypes, which is consistent with the hypothesis that condors were relatively abundant in the nineteenth century, but declined rapidly as a result of human-caused mortality; and (2) no evidence of historical population segregation, meaning that the available genetic data offer no cause to avoid releasing condors in unoccupied portions of their historical range.

  19. Hanging on the line – on the need to assess the risk to global submarine telecommunications infrastructure – an example of the Hawaiian "bottleneck" and Australia

    Directory of Open Access Journals (Sweden)

    D. Dominey-Howes

    2009-04-01

    Full Text Available National economies are becoming increasingly dependent on the global telecommunications system – and in particular, its submarine cable infrastructure. We note that a variety of natural hazard processes are capable of damaging and destroying this infrastructure, both in deep water and at the coast. Some places within the global telecommunications system are already known to be bottlenecks or "choke points". Hawaii is just such a choke point and interestingly, Hawaii is also affected by numerous large magnitude natural hazard processes. Any damage to the submarine telecommunications infrastructure routed through Hawaii could result in significant impacts on the electronic flow of data and voice traffic, negatively affecting dependent economies such as Australia. We propose that proper risk assessments be undertaken at all bottlenecks in the global telecommunications system affected by natural hazards (such as tsunami. We use Hawaii as an example of the sort of research that should be undertaken.

  20. Transmission of human mtDNA heteroplasmy in the Genome of the Netherlands families: support for a variable-size bottleneck

    Science.gov (United States)

    Li, Mingkun; Rothwell, Rebecca; Vermaat, Martijn; Wachsmuth, Manja; Schröder, Roland; Laros, Jeroen F.J.; van Oven, Mannis; de Bakker, Paul I.W.; Bovenberg, Jasper A.; van Duijn, Cornelia M.; van Ommen, Gert-Jan B.; Slagboom, P. Eline; Swertz, Morris A.; Wijmenga, Cisca; Kayser, Manfred; Boomsma, Dorret I.; Zöllner, Sebastian; de Knijff, Peter; Stoneking, Mark

    2016-01-01

    Although previous studies have documented a bottleneck in the transmission of mtDNA genomes from mothers to offspring, several aspects remain unclear, including the size and nature of the bottleneck. Here, we analyze the dynamics of mtDNA heteroplasmy transmission in the Genomes of the Netherlands (GoNL) data, which consists of complete mtDNA genome sequences from 228 trios, eight dizygotic (DZ) twin quartets, and 10 monozygotic (MZ) twin quartets. Using a minor allele frequency (MAF) threshold of 2%, we identified 189 heteroplasmies in the trio mothers, of which 59% were transmitted to offspring, and 159 heteroplasmies in the trio offspring, of which 70% were inherited from the mothers. MZ twin pairs exhibited greater similarity in MAF at heteroplasmic sites than DZ twin pairs, suggesting that the heteroplasmy MAF in the oocyte is the major determinant of the heteroplasmy MAF in the offspring. We used a likelihood method to estimate the effective number of mtDNA genomes transmitted to offspring under different bottleneck models; a variable bottleneck size model provided the best fit to the data, with an estimated mean of nine individual mtDNA genomes transmitted. We also found evidence for negative selection during transmission against novel heteroplasmies (in which the minor allele has never been observed in polymorphism data). These novel heteroplasmies are enhanced for tRNA and rRNA genes, and mutations associated with mtDNA diseases frequently occur in these genes. Our results thus suggest that the female germ line is able to recognize and select against deleterious heteroplasmies. PMID:26916109

  1. A wide range of 3243A>G/tRNALeu(UUR (MELAS mutation loads may segregate in offspring through the female germline bottleneck.

    Directory of Open Access Journals (Sweden)

    Francesco Pallotti

    Full Text Available Segregation of mutant mtDNA in human tissues and through the germline is debated, with no consensus about the nature and size of the bottleneck hypothesized to explain rapid generational shifts in mutant loads. We investigated two maternal lineages with an apparently different inheritance pattern of the same pathogenic mtDNA 3243A>G/tRNALeu(UUR (MELAS mutation. We collected blood cells, muscle biopsies, urinary epithelium and hair follicles from 20 individuals, as well as oocytes and an ovarian biopsy from one female mutation carrier, all belonging to the two maternal lineages to assess mutant mtDNA load, and calculated the theoretical germline bottleneck size (number of segregating units. We also evaluated "mother-to-offspring" segregations from the literature, for which heteroplasmy assessment was available in at least three siblings besides the proband. Our results showed that mutation load was prevalent in skeletal muscle and urinary epithelium, whereas in blood cells there was an inverse correlation with age, as previously reported. The histoenzymatic staining of the ovarian biopsy failed to show any cytochrome-c-oxidase defective oocyte. Analysis of four oocytes and one offspring from the same unaffected mother of the first family showed intermediate heteroplasmic mutant loads (10% to 75%, whereas very skewed loads of mutant mtDNA (0% or 81% were detected in five offspring of another unaffected mother from the second family. Bottleneck size was 89 segregating units for the first mother and 84 for the second. This was remarkably close to 88, the number of "segregating units" in the "mother-to-offspring" segregations retrieved from literature. In conclusion, a wide range of mutant loads may be found in offspring tissues and oocytes, resulting from a similar theoretical bottleneck size.

  2. No Genetic Bottleneck in Plasmodium falciparum Wild-Type Pfcrt Alleles Reemerging in Hainan Island, China, following High-Level Chloroquine Resistance▿

    OpenAIRE

    Chen, Nanhua; Gao, Qi; Wang, Shanqing; Wang, Guangze; Gatton, Michelle; Cheng, Qin

    2007-01-01

    Chloroquine-resistant Plasmodium falciparum was highly prevalent in Hainan, China, in the 1970s. Twenty-five years after cessation of chloroquine therapy, the prevalence of P. falciparum wild-type Pfcrt alleles has risen to 36% (95% confidence interval, 22.1 to 52.4%). The diverse origins of wild-type alleles indicate that there was no genetic bottleneck caused by high chloroquine resistance.

  3. Human migration through bottlenecks from Southeast Asia into East Asia during Last Glacial Maximum revealed by Y chromosomes.

    Science.gov (United States)

    Cai, Xiaoyun; Qin, Zhendong; Wen, Bo; Xu, Shuhua; Wang, Yi; Lu, Yan; Wei, Lanhai; Wang, Chuanchao; Li, Shilin; Huang, Xingqiu; Jin, Li; Li, Hui

    2011-01-01

    Molecular anthropological studies of the populations in and around East Asia have resulted in the discovery that most of the Y-chromosome lineages of East Asians came from Southeast Asia. However, very few Southeast Asian populations had been investigated, and therefore, little was known about the purported migrations from Southeast Asia into East Asia and their roles in shaping the genetic structure of East Asian populations. Here, we present the Y-chromosome data from 1,652 individuals belonging to 47 Mon-Khmer (MK) and Hmong-Mien (HM) speaking populations that are distributed primarily across Southeast Asia and extend into East Asia. Haplogroup O3a3b-M7, which appears mainly in MK and HM, indicates a strong tie between the two groups. The short tandem repeat network of O3a3b-M7 displayed a hierarchical expansion structure (annual ring shape), with MK haplotypes being located at the original point, and the HM and the Tibeto-Burman haplotypes distributed further away from core of the network. Moreover, the East Asian dominant haplogroup O3a3c1-M117 shows a network structure similar to that of O3a3b-M7. These patterns indicate an early unidirectional diffusion from Southeast Asia into East Asia, which might have resulted from the genetic drift of East Asian ancestors carrying these two haplogroups through many small bottle-necks formed by the complicated landscape between Southeast Asia and East Asia. The ages of O3a3b-M7 and O3a3c1-M117 were estimated to be approximately 19 thousand years, followed by the emergence of the ancestors of HM lineages out of MK and the unidirectional northward migrations into East Asia. PMID:21904623

  4. Human migration through bottlenecks from Southeast Asia into East Asia during Last Glacial Maximum revealed by Y chromosomes.

    Directory of Open Access Journals (Sweden)

    Xiaoyun Cai

    Full Text Available Molecular anthropological studies of the populations in and around East Asia have resulted in the discovery that most of the Y-chromosome lineages of East Asians came from Southeast Asia. However, very few Southeast Asian populations had been investigated, and therefore, little was known about the purported migrations from Southeast Asia into East Asia and their roles in shaping the genetic structure of East Asian populations. Here, we present the Y-chromosome data from 1,652 individuals belonging to 47 Mon-Khmer (MK and Hmong-Mien (HM speaking populations that are distributed primarily across Southeast Asia and extend into East Asia. Haplogroup O3a3b-M7, which appears mainly in MK and HM, indicates a strong tie between the two groups. The short tandem repeat network of O3a3b-M7 displayed a hierarchical expansion structure (annual ring shape, with MK haplotypes being located at the original point, and the HM and the Tibeto-Burman haplotypes distributed further away from core of the network. Moreover, the East Asian dominant haplogroup O3a3c1-M117 shows a network structure similar to that of O3a3b-M7. These patterns indicate an early unidirectional diffusion from Southeast Asia into East Asia, which might have resulted from the genetic drift of East Asian ancestors carrying these two haplogroups through many small bottle-necks formed by the complicated landscape between Southeast Asia and East Asia. The ages of O3a3b-M7 and O3a3c1-M117 were estimated to be approximately 19 thousand years, followed by the emergence of the ancestors of HM lineages out of MK and the unidirectional northward migrations into East Asia.

  5. Homopolymeric tract heteroplasmy in mtDNA from tissues and single oocytes: Support for a genetic bottleneck

    Energy Technology Data Exchange (ETDEWEB)

    Marchington, D.R.; Hartshorne, G.M.; Barlow, D.; Poulton, J. [Univ. of Oxford (United Kingdom)

    1997-02-01

    While mtDNA polymorphisms at single base positions are common, the overwhelming majority of the mitochondrial genomes within a single individual are usually identical. When there is a point-mutation difference between a mother and her offspring, there may be a complete switching of mtDNA type within a single generation. It is generally assumed that there is a genetic bottleneck whereby a single or small number of founder mtDNA(s) populate the organism, but it is not known at which stages the restriction/amplification of mtDNA subtype(s) occur, and this uncertainty impedes antenatal diagnosis for mtDNA disorders. Length polymorphisms in homopolymeric tracts have been demonstrated in the large noncoding region of mtDNA. We have developed a new method, T-PCR (trimmed PCR), to quantitate heteroplasmy for two of these tracts (D310 and D16189). D310 variation is sufficient to indicate clonal origins of tissues and single oocytes. Tissues from normal individuals often possessed more than one length variant (heteroplasmy). However, there was no difference in the pattern of the length variants between somatic tissues in any control individual when bulk samples were taken. Oocytes from normal women undergoing in vitro fertilization were frequently heteroplasmic for length variants, and in two cases the modal length of the D310 tract differed in individual oocytes from the same woman. These data suggest that a restriction/amplification event, which we attribute to clonal expansion of founder mtDNA(s), has occurred by the time oocytes are mature, although further segregation may occur at a later stage. In contrast to controls, the length distribution of the D310 tract varied between tissues in a patient with heteroplasmic mtDNA rearrangements, suggesting that these mutants influence segregation. These findings have important implications for the genetic counselling of patients with pathogenic mtDNA mutations. 21 refs., 5 figs., 1 tab.

  6. Global change ecotoxicology: Identification of early life history bottlenecks in marine invertebrates, variable species responses and variable experimental approaches.

    Science.gov (United States)

    Byrne, M

    2012-05-01

    Climate change is a threat to marine biota because increased atmospheric CO₂ is causing ocean warming, acidification, hypercapnia and decreased carbonate saturation. These stressors have toxic effects on invertebrate development. The persistence and success of populations requires all ontogenetic stages be completed successfully and, due to their sensitivity to environmental stressors, developmental stages may be a population bottleneck in a changing ocean. Global change ecotoxicology is being used to identify the marine invertebrate developmental stages vulnerable to climate change. This overview of research, and the methodologies used, shows that most studies focus on acidification, with few studies on ocean warming, despite a long history of research on developmental thermotolerance. The interactive effects of stressors are poorly studied. Experimental approaches differ among studies. Fertilization in many species exhibits a broad tolerance to warming and/or acidification, although different methodologies confound inter-study comparisons. Early development is susceptible to warming and most calcifying larvae are sensitive to acidification/increased pCO₂. In multistressor studies moderate warming diminishes the negative impact of acidification on calcification in some species. Development of non-calcifying larvae appears resilient to near-future ocean change. Although differences in species sensitivities to ocean change stressors undoubtedly reflect different tolerance levels, inconsistent handling of gametes, embryos and larvae probably influences different research outcomes. Due to the integrative 'developmental domino effect', life history responses will be influenced by the ontogenetic stage at which experimental incubations are initiated. Exposure to climate change stressors from early development (fertilization where possible) in multistressor experiments is needed to identify ontogenetic sensitivities and this will be facilitated by more consistent

  7. Sensitivity of Material-flow Bottleneck to Uncertain Environment in Job Shop%物料流瓶颈对制造车间不确定环境的敏感性研究

    Institute of Scientific and Technical Information of China (English)

    凌琳; 刘明周; 王强

    2013-01-01

    The method for measuring the sensitivity of the bottleneck degree to the bottleneck shifting factors was proposed. According to the material-flow bottleneck defining, the production capability and load were described from the perspectives of process speed and quality level, then the bottleneck index was constructed to characterize the degree of manufacturing unit blocking the material-flow ( that is bottleneck degree). Based on the measurement of the sensitivity of the bottleneck index to the single bottleneck shifting factor and DEMATEL method for analyzing the relationship of the factors, bottleneck shifting sensitivity index was built to measure the sensitive degree of bottleneck index to the uncertain environment. At the end of this thesis, an example for monitoring the bottleneck and measuring sensitive degree to the uncertain environment in job shop was given to prove the validation and practicability of bottleneck index and bottleneck shifting sensitivity index.%提出了物料流瓶颈对瓶颈漂移因素的敏感性度量方法.通过定义物料流瓶颈,从生产速率和生产质量两个方面综合度量制造单元生产能力和需求,并提出物料流瓶颈指数用于表征制造单元阻碍制造车间物料流流动平顺性的程度(即物料流瓶颈程度);分显性和隐性瓶颈漂移因素测度制造单元瓶颈指数对各因素的敏感性,并利用DEMATEL方法分析因素间的相互关联关系,在此基础上提出瓶颈漂移敏感指数度量物料流瓶颈对制造车间不确定环境的敏感程度;最后,通过对某一制造车间内物料流瓶颈和瓶颈程度对不确定环境的敏感性的度量和监测,验证了瓶颈指数和瓶颈漂移敏感指数的有效性和实用性.

  8. Microscopic Theory of Traffic Flow Instability Governing Traffic Breakdown at Highway Bottlenecks: Growing Wave of Increase in Speed in Synchronized Flow

    CERN Document Server

    Kerner, Boris S

    2015-01-01

    We have revealed a growing local speed wave of increase in speed that can randomly occur in synchronized flow (S) at a highway bottleneck. The development of such a traffic flow instability leads to free flow (F) at the bottleneck; therefore, we call this instability as an S$\\rightarrow$F instability. Whereas the S$\\rightarrow$F instability leads to a local {\\it increase in speed} (growing acceleration wave), in contrast, the classical traffic flow instability introduced in 50s--60s and incorporated later in a huge number of traffic flow models leads to a growing wave of a local {\\it decrease in speed} (growing deceleration wave). We have found that the S$\\rightarrow$F instability can occur only, if there is a finite time delay in driver over-acceleration. The initial speed disturbance of increase in speed (called "speed peak") that initiates the S$\\rightarrow$F instability occurs usually at the downstream front of synchronized flow at the bottleneck. There can be many speed peaks with random amplitudes that ...

  9. Effect of Driver Behavior on Spatiotemporal Congested Traffic Patterns at Highway Bottlenecks in the Framework of Three-Phase Traffic Theory

    CERN Document Server

    Kerner, Boris S

    2010-01-01

    We present results of numerical simulations of the effect of driver behavior on spatiotemporal congested traffic patterns that result from traffic breakdown at an on-ramp bottleneck. The simulations are made with the Kerner-Klenov stochastic traffic flow model in the framework of three-phase traffic theory. Different diagrams of congested patterns at the bottleneck associated with different driver behavioral characteristics are found and compared each other. An adaptive cruise control (ACC) in the framework of three-phase traffic theory introduced by the author (called a "driver alike ACC" (DA-ACC)) is discussed. The effect of DA-ACC-vehicles on traffic flow, in which without the DA-ACC-vehicles traffic congestion occurs at the bottleneck, is numerically studied. We show that DA-ACC-vehicles improve traffic flow considerably without any reduction in driving comfort. It is found that there is a critical percentage of DA-ACC-vehicles in traffic flow: If the percentage of the DA-ACC-vehicle exceeds the critical ...

  10. A range-wide genetic bottleneck overwhelms contemporary landscape factors and local abundance in shaping genetic patterns of an alpine butterfly (Lepidoptera: Pieridae: Colias behrii).

    Science.gov (United States)

    Schoville, Sean D; Lam, Athena W; Roderick, George K

    2012-09-01

    Spatial and environmental heterogeneity are major factors in structuring species distributions in alpine landscapes. These landscapes have also been affected by glacial advances and retreats, causing alpine taxa to undergo range shifts and demographic changes. These nonequilibrium population dynamics have the potential to obscure the effects of environmental factors on the distribution of genetic variation. Here, we investigate how demographic change and environmental factors influence genetic variation in the alpine butterfly Colias behrii. Data from 14 microsatellite loci provide evidence of bottlenecks in all population samples. We test several alternative models of demography using approximate Bayesian computation (ABC), with the results favouring a model in which a recent bottleneck precedes rapid population growth. Applying independent calibrations to microsatellite loci and a nuclear gene, we estimate that this bottleneck affected both northern and southern populations 531-281 years ago, coinciding with a period of global cooling. Using regression approaches, we attempt to separate the effects of population structure, geographical distance and landscape on patterns of population genetic differentiation. Only 40% of the variation in F(ST) is explained by these models, with geographical distance and least-cost distance among meadow patches selected as the best predictors. Various measures of genetic diversity within populations are also decoupled from estimates of local abundance and habitat patch characteristics. Our results demonstrate that demographic change can have a disproportionate influence on genetic diversity in alpine species, contrasting with other studies that suggest landscape features control contemporary demographic processes in high-elevation environments. PMID:22849440

  11. The knowledge reengineering bottleneck

    NARCIS (Netherlands)

    R. Hoekstra

    2010-01-01

    Knowledge engineering upholds a longstanding tradition that emphasises methodological issues associated with the acquisition and representation of knowledge in some (formal) language. This focus on methodology implies an ex ante approach: "think before you act". The rapid increase of linked data pos

  12. Achievements and bottlenecks in humanitarian demining EU-funded research: final results from the EC DELVE project

    Science.gov (United States)

    Sahli, Hichem; Bruschini, Claudio; Van Kempen, Luc; Schleijpen, Ric; den Breejen, Eric

    2008-04-01

    The EC DELVE Support Action project has analyzed the bottlenecks in the transfer of Humanitarian Demining (HD) technology from technology development to the use in the field, and drawn some lessons learned, basing itself on the assessment of the European Humanitarian Demining Research and Technology Development (RTD) situation from early 1990 until 2006. The situation at the European level was analyzed with emphasis on activities sponsored by the European Commission (EC). This was also done for four European countries and Japan, with emphasis on national activities. The developments in HD during the last 10 years underline the fact that in a number of cases demining related developments have been terminated or at least put on hold. The study also showed that the funding provided by the EC under the Framework Program for RTD has led directly to the creation of an extensive portfolio of Humanitarian Demining technology development projects. The latter provided a range of research and supporting measures addressing the critical issues identified as a result of the regulatory policies developed in the field of Humanitarian Demining over the last ten years. However, the range of instruments available to the EC to finance the necessary research and development were limited, to pre-competitive research. The EC had no tools or programs to directly fund actual product development. As a first consequence, the EC funding program for development of technology for Humanitarian Demining unfortunately proved to be largely unsuitable for the small-scale development needed in a field where there is only a very limited market. As a second consequence, most of the research has been demonstrator-oriented. Moreover, the timeframe for RTD in Humanitarian Demining has not been sufficiently synchronized with the timeframe of the EC policies and regulations. The separation of the Mine Action and RTD funding streams in the EC did also negatively affect the take-up of new technologies. As a

  13. Multi-bottleneck scheduling algorithm for large-scale Job Shop%大规模作业车间多瓶颈调度算法

    Institute of Scientific and Technical Information of China (English)

    翟颖妮; 孙树栋; 杨宏安; 牛刚刚; 袁宗寅

    2011-01-01

    To solve Large-Scale Job Shop Scheduling Problems(LSJSSP), a multi-bottleneck scheduling algorithm based on rolling horizon decomposition was proposed. This algorithm adopted critical path method to detect bottlenecks, and solved the LSJSSP by decomposing it into a series of sub-problems according to the process routines of the jobs. In the construction process of the sub-problems, the idea of load balanced distribution was proposed to distribute the load of each job in the sub-problems and to realize the stability of the solution process. In the solving process of the sub-problems. The bottleneck operations were scheduled by genetic algorithm, and the non-bottleneck operations were scheduled by dispatching rules according to the principle of "bottleneck machines lead non-bottleneck machines" in Theory of Constraints (TOC), the solving efficiency was improved. Through re-optimization process for the overlapping operations in the adjacent sub-problems and the strategy of evaluating the chromosome's fitness by the global solution, limitations of the decomposition and solving process were avoided, and the solution quality was improved. Simulation results showed that the proposed algorithm for LSJSSP was with satisfactory solution efficiency and quality.%针对大规模作业车间调度问题,提出一种基于滚动窗分解的多瓶颈调度算法.该算法基于关键路径法进行多瓶颈机器的识别,沿时域将大规模调度问题分解为多个子问题进行求解.在子问题创建过程中,提出负荷均衡分布的规则,使得各工件在各子问题中的负荷均匀分布,以实现算法求解过程的稳定性;在子问题的求解过程中,遵循约束理论中瓶颈机主导非瓶颈机的原则,采用瓶颈工序最优化调度、非瓶颈工序采用分派规则快速调度的调度策略,提高算法的求解效率;通过相邻子问题间的工序衔接再优化过程,以及全局解评价子问题染色体适应度值策略,有效避

  14. Operational Capacity on Freeway Bottleneck Segment%高速公路瓶颈路段运营通行能力研究

    Institute of Scientific and Technical Information of China (English)

    吴德华; 邱志军

    2015-01-01

    高速公路瓶颈路段在发生交通拥堵后会引起运营通行能力突变现象,为了更加准确揭示瓶颈路段运营通行能力变化规律,引入非对称驾驶行为理论,改进Newell跟车模型,并对模型进行参数估计和应用分析.通过12个仿真场景及试验数据对比分析了改进模型和美国道路通行能力手册(2010)推荐模型的精确度,发现改进模型可以提高精度;分析了因车道减少导致的交通拥堵,发现关闭不同车道和车道数对运营通行能力影响结果不同,得出了相应的影响值;在一定交通量范围内,入口匝道和出口匝道交通量的增加都会导致主线拥堵路段运营通行能力的降低,并给出了最大降低幅度.研究结果可为缓解高速公路瓶颈路段交通拥堵提供借鉴.%The traffic congestion can cause operational capacity drop phenomenon on freeway bottleneck segment. To reveal the capacity diversification regular pattern, the asymmetric driver behavior theory is used to improve the Newell car-following model. The improved car-following model is calibrated and implemented in field data simulation. By 12 simulation scenarios and field data analysis, the results show that the improved Newell car-following model can increase accuracy in estimate the bottleneck operational capacity compared to the model that Highway Capacity Manual (HCM2010) provided. The traffic congestion due to the lane drop is analyzed, the operational capacity varied in condition close different lane and number of lanes, then the varied value is figured out. The operational capacity on major lane bottleneck segment decreases by changed the flow on on-ramp and off-ramp in range of certain flow change, and the most decreased value is calculated. In conclusion, the results can provide reference for migrate congestion on freeway bottleneck segment.

  15. 学前教育事业发展的瓶颈问题讨论%Bottlenecks in the Development of Preschool Education

    Institute of Scientific and Technical Information of China (English)

    段媛媛

    2015-01-01

    To achieve the goal of the current development of preschool education, preschool education reform and develop-ment so that more effective and targeted preschool education should be aware of the bottlenecks in the development of China, recognize problems of practical reasons. Bottlenecks preschool education should focus on the development of China include:the rational allocation of educational resources, investment funds issue preschool finance, office park construction quality as-sessment and management mechanisms and survival kindergarten teachers and professional development.%为实现当前学前教育发展的目标,使学前教育改革和发展更具有效性和针对性,应了解我国学前教育事业发展中的瓶颈,认清问题产生的现实原因.我国学前教育事业发展应关注的瓶颈问题包括:教育资源的合理配置问题,学前教育财政经费的投入问题,办园质量评估与管理机制建设以及幼儿园教师生存与专业发展问题.

  16. Widening Synthesis Bottlenecks: Realization of Ultrafast and Continuous-Flow Synthesis of High-Silica Zeolite SSZ-13 for NOx Removal.

    Science.gov (United States)

    Liu, Zhendong; Wakihara, Toru; Oshima, Kazunori; Nishioka, Daisuke; Hotta, Yuusuke; Elangovan, Shanmugam P; Yanaba, Yutaka; Yoshikawa, Takeshi; Chaikittisilp, Watcharop; Matsuo, Takeshi; Takewaki, Takahiko; Okubo, Tatsuya

    2015-05-01

    Characteristics of zeolite formation, such as being kinetically slow and thermodynamically metastable, are the main bottlenecks that obstruct a fast zeolite synthesis. We present an ultrafast route, the first of its kind, to synthesize high-silica zeolite SSZ-13 in 10 min, instead of the several days usually required. Fast heating in a tubular reactor helps avoid thermal lag, and the synergistic effect of addition of a SSZ-13 seed, choice of the proper aluminum source, and employment of high temperature prompted the crystallization. Thanks to the ultra-short period of synthesis, we established a continuous-flow preparation of SSZ-13. The fast-synthesized SSZ-13, after copper-ion exchange, exhibits outstanding performance in the ammonia selective catalytic reduction (NH3 -SCR) of nitrogen oxides (NOx ), showing it to be a superior catalyst for NOx removal. Our results indicate that the formation of high-silica zeolites can be extremely fast if bottlenecks are effectively widened. PMID:25801140

  17. Maintenance of genetic diversity in an introduced island population of guanacos after seven decades and two severe demographic bottlenecks: implications for camelid conservation.

    Science.gov (United States)

    González, Benito A; Orozco-Terwengel, Pablo; von Borries, Rainer; Johnson, Warren E; Franklin, William L; Marín, Juan C

    2014-01-01

    Fifteen guanacos were introduced to Staats Island in the Falklands/Malvinas archipelago from Patagonia in the 1930s. Twenty five years later, the population was culled from 300 to 10-20 individuals, but quickly rebounded to a population of almost 400 animals that today retain the genetic signature of the founding event and later bottleneck. The goals of this study were to (i) make a genetic assessment of this island population through comparisons with mainland populations and simulations, and (ii) assess the likely source-population of the introduced guanacos. Genetic variation was estimated from 513 bp of mitochondrial DNA sequence and 15 microsatellite loci among 154 guanacos collected from eight localities, including the adjacent mainland and the islands of Tierra del Fuego and Staats Island. Of the 23 haplotypes observed among our samples, the Staats Island population only contained three haplotypes, all of which were shared with the coastal Monte Leon population in southern Patagonia. Mitochondrial DNA and microsatellite variations on Staats Island were comparable to most mainland populations and greater than those observed on Tierra del Fuego. Patterns of genetic structure suggest that the Staats Island guanaco population was founded with animals from southern Patagonia (as opposed to northern Patagonia or Tierra del Fuego), but that effective reductions in population size lasted only a few generations and that surviving animals were a random sample of the pre-bottleneck genetic variation. PMID:24663026

  18. Demographic and genetic factors in the recovery or demise of ex situ populations following a severe bottleneck in fifteen species of Hawaiian tree snails.

    Science.gov (United States)

    Price, Melissa R; Sischo, David; Pascua, Mark-Anthony; Hadfield, Michael G

    2015-01-01

    Wild populations of endangered Hawaiian tree snails have declined precipitously over the last century due to introduced predators and other human impacts. Life history traits, such as very low fecundity (species were collected from the wild to initiate captive-reared populations as a hedge against extinction. This small number of founders resulted in a severe bottleneck in each of the captive-reared populations. We identified key demographic parameters that predicted population recovery from this bottleneck. Species with captive populations that produced between two and four offspring per adult per year and had 20-50% of those offspring survive to maturity recovered to numbers above 100 individuals, and maintained viable populations following a decline that occurred between 2009 and 2014. Those populations that had less than two offspring per adult per year and less than 20% survival to maturity did not reach 100 individuals in captivity, and many of these populations died out during the recent decline. We suggest that small reductions in fitness may contribute to extirpation in taxa with inherently low fecundity, by keeping populations below a threshold number essential to long-term recovery. Future ex situ populations should be founded with no less than 15 adults, and maintained in conditions closely approximating the temperature and humidity of source locations to optimize fitness. Permanent translocations of wild populations for conservation purposes will be more likely to succeed with greater than 100 adults, and should be limited to locations with a similar climate to source locations. PMID:26587358

  19. 中国MOOC发展现状与瓶颈研究%Research on the Current Situation and Bottlenecks of MOOC Development in China

    Institute of Scientific and Technical Information of China (English)

    王晶

    2016-01-01

    本文主要针对我国MOOC发展的现状和瓶颈进行分析研究,重点介绍了MOOC平台建设、SPOC模式应用以及专业技能教育MOOC的发展,从MOOC交流工具、学习成果认证、可持续发展三个方面对MOOC的瓶颈进行研究并提出建议,期望对今后MOOC更好的发展提供帮助。%This paper mainly analyzed and studied the current situation and bottlenecks of MOOC develop⁃ment in our country, focused on the introduction of MOOC platform establishment, SPOC mode application and the development of professional skills education MOOC, and studied MOOC bottlenecks from three aspects of MOOC communication tools, certification of learning outcomes, and sustainable development and put forward suggestions, hoping to provide assistance for the better development of MOOC in the future.

  20. Physician deficit in USA - where is the bottleneck? [Ärztemangel in den USA - wo wird es eng?

    Directory of Open Access Journals (Sweden)

    Walid, M. Sami

    2009-05-01

    Full Text Available [english] The population of physician professionals in the US has been carefully controlled over the last century to ensure profitable work for people in the profession and provide physician workforce for the nation. However, the emergence of managed care in the US has spurred speculations that the US will experience a substantial excess of physicians by the beginning of the 21st century. In light of these forecasts, the number of residency positions funded by Medicare has been restricted. Additionally, enrollment at allopathic medical schools has been decreasing over the last two decades of the Twentieth Century. It is now evident that those predictions were erroneous and that the current supply of physicians does not exceed the demand for their services. That is why the Association of American Medical Colleges now aims to increase the number of US medical school graduates by 3,000 yearly by the year 2015. However, even if this difficult mission can be accomplished, the US can still have a deficit of 200,000 physicians by the year 2020. The reason is the bottleneck that controls the flow of medical graduates aiming to enter residency programs and get clinical training in order to obtain the license required to practice medicine. With the restriction on the number of Medicare-funded residency positions in the US an increase in US medical school graduates will only displace an equal number of international medical graduates applying for residency positions and consequently reduce the number of international medical graduates who join the physician workforce. This will probably not increase the number of practicing physicians. Shortage of physicians will remain an issue and undeniably make access to medical care problematic for all citizens. [german] Im 20. Jahrhundert wurde die Zahl der Ärzte in den Vereinigten Staaten sorgfältig reguliert, um lohnende Arbeitsbedingungen im ärztlichen Beruf und die Versorgung mit Ärzten für die Bev

  1. Using 5S Field Management Activities to Promote the TOC Bottleneck Management in Workshop%运用5S现场管理活动推进车间实施TOC瓶颈管理

    Institute of Scientific and Technical Information of China (English)

    史丙强

    2014-01-01

    The 5S on-site management is the tool of production system to carry out TOC bottleneck management, and makes the TOC bottleneck management easy to work. Bottleneck management thought provides guidance and direction for the development of 5S on-site management work.%院5S现场管理是生产系统推行TOC瓶颈管理的工具,使TOC瓶颈管理工作开展简单易行;瓶颈管理的思想,为5S现场管理工作的开展提供指导,指明方向。

  2. 大规模无线网络中(X,S)-Bottleneck区域性能分析%Performance Analysis of (X, S)-Bottleneck Cell in Large-Scale Wireless Networks

    Institute of Scientific and Technical Information of China (English)

    颜国风; 王建新; 陈淑红

    2012-01-01

    The performance analytical model for (X,S)-bottleneck cell is proposed and perform some probabilistic analysis on the performances of (X,S)-bottleneck cell, such as the probability of balance state, the transmission probability of a flow, and the throughput of (X,S)-bottleneck cell. To capture the essential aspects of (X,S)-bottleneck cell, two-hierarchy Quasi Birth-Death models (QBDs) are used to model the (X,S)-bottleneck cell. The general characters of (X,S)-bottleneck cell are govern by the first hierarchy QBDs, while the characters of each flow are captured by the second hierarchy QBDs. Based on the analytical model, a methodology to derive the balance-state probability of (X,S>bottleneck cell is proposed, and some theoretic ranges for the transmission probability of a flow and the throughput. The simulations show that the proposed model can analyze effectively the performance of (X,S)-bottleneck cell. The results are helpful for improving and managing wireless networks.%基于二层QBDs(quasi birth-death models),提出了一个(X,S)-bottleneck区域性能分析模型,(X,S)-bottleneck区域的特征通过第1层QBD模型描述,而经过(X,S)-bottleneck区域的每条流的特征由第2层QBD模型描述.基于该性能分析模型,对(X,S)-bottleneck区域的性能进行了一些概率分析,如(X,S)-bottleneck区域的平衡状态概率、经过该区域通信流的成功转发概率和吞吐量等,确定了上述概率及吞吐量的取值范围,仿真实验结果表明了该性能分析模型对于分析(X,S)-bottleneck区域性能的有效性.结论有助于无线网络通信性能的改进和管理.

  3. Development status, bottleneck and trend of China cosmetic industry%我国化妆品行业发展现状、瓶颈及趋势

    Institute of Scientific and Technical Information of China (English)

    郭华山

    2012-01-01

    China cosmetic market status and features were introduced, and its import and export data were analyzed. Meanwhile, both current problems and bottleneck in the process of cosmetic market development as well as future measures and strategies were pointed out. Finally, development trend of cosmetic industry was put forward.%对中国整个化妆品市场现状和特征进行了阐述,对2011年的进出口数据进行了深入分析。同时,指出了中国化妆品市场发展过程中遇到的问题、发展瓶颈以及今后几年的发展措施和战略。最后,对今后化妆品行业的发展趋势进行了总结。

  4. Population-based resequencing analysis of wild and cultivated barley revealed weak domestication signal of selection and bottleneck in the Rrs2 scald resistance gene region.

    Science.gov (United States)

    Fu, Yong-Bi

    2012-02-01

    Many plant disease resistance (R) genes have been cloned, but the potential of utilizing these plant R-gene genomic resources for genetic inferences of plant domestication history remains unexplored. A population-based resequencing analysis of the genomic region near the Rrs2 scald resistance gene was made in 51 accessions of wild and cultivated barley from 41 countries. Fifteen primer pairs were designed to sample the genomic region with a total length of 10 406 bp. More nucleotide diversity was found in wild (π = 0.01846) than cultivated (π = 0.01507) barley samples. Three distinct groups of 29 haplotypes were detected for all 51 samples, and they were well mixed with wild and cultivated barley samples from different countries and regions. The neutrality tests by Tajima's D were not significant, but a significant (P domestication. Together, the domestication signal in the genomic region was weak both in human selection and domestication bottleneck.

  5. Bottleneck oriented load planning in heat treatment. Optimizing the production flow cuts down on time and resources; Engpassorientierte Feinplanung in der Waermebehandlung. Optimaler Teilefluss spart Zeit und Ressourcen

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Karl-Michael [PROCESS-ELECTRONIC GmbH, Heiningen (Germany)

    2010-06-15

    Making money in heat treating is getting more and more demanding. There is obviously the economical crisis causing the biggest impact on all of us, nevertheless knowing the true dynamic capacity of our - still partially turned down - equipment and being able to squeeze out even the smallest capability will optimize the cost to earnings ratio. Everyone is using computer systems in order to plan their work-flow, however, often a disadvantage of such systems is their missing knowledge of what has to be done with the parts when it comes to breaking down the shop orders into real loads. This article is giving an overview on the existing planning layers and what different methods are used and explains how planning consequently around bottle-necks will result in an optimized throughput while at the same time trying to minimize the total number of equipment used - hence saving resources. (orig.)

  6. 我国微型企业融资瓶颈分析%Analysis of Financing Bottlenecks in the Course of China's Micro-enterprise's Development

    Institute of Scientific and Technical Information of China (English)

    谭淑霞

    2012-01-01

    近年来,在地区经济的发展中,微型企业发挥着越来越为重要的作用,已经成为吸纳地区就业的重要力量.本文针对微型企业发展中融资瓶颈问题进行了深入分析,并提出提高我国微型企业融资效率的对策.%In recent years, Micro-enterprises play an increasingly important role in the regional economic development. It has become an important force for employment. This paper makes an in-depth analysis of the financing bottlenecks in the course of the micro-enterprise's development. And then some strategies has been proposed to increase the efficiency of the micro-enterprise financing.

  7. Evidence for a response preparation bottleneck during dual-task performance: effect of a startling acoustic stimulus on the psychological refractory period.

    Science.gov (United States)

    Maslovat, Dana; Chua, Romeo; Spencer, Hunter C; Forgaard, Christopher J; Carlsen, Anthony N; Franks, Ian M

    2013-11-01

    The present study was designed to investigate the mechanism associated with dual-task interference in a psychological refractory period (PRP) paradigm. We used a simple reaction time paradigm consisting of a vocal response (R1) and key-lift task (R2) with a stimulus onset asynchrony (SOA) between 100ms and 1500ms. On selected trials we implemented a startling acoustic stimulus concurrent with the second stimulus to determine if we could involuntarily trigger the second response. Our results indicated that the PRP delay in the second response was present for both control and startle trials at short SOAs, suggesting the second response was not prepared in advance. These results support a response preparation bottleneck and can be explained via a neural activation model of preparation. In addition, we found that the reflexive startle activation was reduced in the dual-task condition for all SOAs, a result we attribute to prepulse inhibition associated with dual-task processing.

  8. A comparison of the psychological refractory period and prioritized processing paradigms: Can the response-selection bottleneck model explain them both?

    Science.gov (United States)

    Miller, Jeff; Durst, Moritz

    2015-10-01

    Four experiments examined whether well-established phenomena from the psychological refractory period (PRP) paradigm are also observed in the prioritized processing paradigm, as would be expected from a common description of the 2 paradigms with the response selection bottleneck (RSB) model. Consistent with a generalization of the RSB model to the prioritized processing paradigm, Experiments 1 and 2 showed that this paradigm yields effects of SOA and stimulus discriminability analogous to those observed in the PRP paradigm. In Experiments 3 and 4, however, overall RTs and effect sizes differed between the PRP and prioritized processing paradigms in ways that are difficult to explain within the RSB model. Understanding the differences between these 2 paradigms offers considerable promise as a way to extend the RSB model beyond the domain of the PRP paradigm and to generalize our understanding of multitasking interference.

  9. Enriching the Metadata on CERN Document Server And Implementation of a Book Acquisition System To Predict the potential bottlenecks in availability of records in Library

    CERN Document Server

    Ahuja, Chakshu

    2015-01-01

    The automated script for data acquisition project ( bibtasklet ) which aims to enhance existing metadata in our CERN Document Server with data from Springer was implemented. An implicit part of this task is to manage disambiguation (within incoming data), removal of multiple entries, handle replications between new and existing records and further automate the latest file upload task to CDS. All such elements and their corresponding changes are integrated within Invenio to make the upgraded metadata available on the CDS. Another implementation was to make a web interface for the invenio software to calculate the normalized loan period to help the librarians to predict bottleneck on the books on loan over certain period of time and facilitate their decision to buy the new records accordingly.

  10. 一种互联网接入带宽瓶颈解决方法探讨%Discussion on a Solution of Bandwidth Bottleneck of Internet Access

    Institute of Scientific and Technical Information of China (English)

    田东旭

    2013-01-01

    Aiming at the rapid development of computer network information technology and the great improvement of network bandwidth rate, the wide disparity between local area network exportation bandwidth requirement and Internet access bandwidth requirement is formed, which causes the bandwidth bottleneck of Internet access of multi- user group. Firstly, this paper compares the advantages and disadvantages of such two traditional solutions as desk port rate limit and service port blocking. Finally, this paper presents a single user rate limit based on network management platform based on discussion and analysis in detail, in order to guarantee that more users can simultaneously use the band- limited Internet resources, and solve the bandwidth bottleneck problem of Internet exportation of multi- user group.%针对当前计算机网络信息技术高速发展,网络带宽速率大幅提升,形成局域网出口带宽需求与互联网接入带宽之间差距悬殊,而引发了多用户团体互联网接入带宽瓶颈问题。首先对比了桌面端口限速和服务端口封堵两种传统解决思路的优劣,通过详细讨论分析,最后给出了一种基于网管平台的单用户限速,能够保证更多用户同时使用有限带宽的互联网资源,解决了多用户团体互联网出口带宽瓶颈问题。

  11. Pathways of Lipid Metabolism in Marine Algae, Co-Expression Network, Bottlenecks and Candidate Genes for Enhanced Production of EPA and DHA in Species of Chromista

    Directory of Open Access Journals (Sweden)

    Alice Mühlroth

    2013-11-01

    Full Text Available The importance of n-3 long chain polyunsaturated fatty acids (LC-PUFAs for human health has received more focus the last decades, and the global consumption of n-3 LC-PUFA has increased. Seafood, the natural n-3 LC-PUFA source, is harvested beyond a sustainable capacity, and it is therefore imperative to develop alternative n-3 LC-PUFA sources for both eicosapentaenoic acid (EPA, 20:5n-3 and docosahexaenoic acid (DHA, 22:6n-3. Genera of algae such as Nannochloropsis, Schizochytrium, Isochrysis and Phaedactylum within the kingdom Chromista have received attention due to their ability to produce n-3 LC-PUFAs. Knowledge of LC-PUFA synthesis and its regulation in algae at the molecular level is fragmentary and represents a bottleneck for attempts to enhance the n-3 LC-PUFA levels for industrial production. In the present review, Phaeodactylum tricornutum has been used to exemplify the synthesis and compartmentalization of n-3 LC-PUFAs. Based on recent transcriptome data a co-expression network of 106 genes involved in lipid metabolism has been created. Together with recent molecular biological and metabolic studies, a model pathway for n-3 LC-PUFA synthesis in P. tricornutum has been proposed, and is compared to industrialized species of Chromista. Limitations of the n-3 LC-PUFA synthesis by enzymes such as thioesterases, elongases, acyl-CoA synthetases and acyltransferases are discussed and metabolic bottlenecks are hypothesized such as the supply of the acetyl-CoA and NADPH. A future industrialization will depend on optimization of chemical compositions and increased biomass production, which can be achieved by exploitation of the physiological potential, by selective breeding and by genetic engineering.

  12. Genetic Signatures of Demographic Changes in an Avian Top Predator during the Last Century: Bottlenecks and Expansions of the Eurasian Eagle Owl in the Iberian Peninsula.

    Directory of Open Access Journals (Sweden)

    Eva Graciá

    Full Text Available The study of the demographic history of species can help to understand the negative impact of recent population declines in organisms of conservation concern. Here, we use neutral molecular markers to explore the genetic consequences of the recent population decline and posterior recovery of the Eurasian eagle owl (Bubo bubo in the Iberian Peninsula. During the last century, the species was the object of extermination programs, suffering direct persecution by hunters until the 70's. Moreover, during the last decades the eagle owl was severely impacted by increased mortality due to electrocution and the decline of its main prey species, the European rabbit (Oryctolagus cuniculus. In recent times, the decrease of direct persecution and the implementation of some conservation schemes have allowed the species' demographic recovery. Yet, it remains unknown to which extent the past population decline and the later expansion have influenced the current species' pattern of genetic diversity. We used eight microsatellite markers to genotype 235 eagle owls from ten Spanish subpopulations and analyse the presence of genetic signatures attributable to the recent population fluctuations experienced by the species. We found moderate levels of differentiation among the studied subpopulations and Bayesian analyses revealed the existence of three genetic clusters that grouped subpopulations from central, south-western and south-eastern Spain. The observed genetic structure could have resulted from recent human-induced population fragmentation, a patchy distribution of prey populations and/or the philopatric behaviour and habitat selection of the species. We detected an old population bottleneck, which occurred approximately 10,000 years ago, and significant signatures of recent demographic expansions. However, we did not find genetic signatures for a recent bottleneck, which may indicate that population declines were not severe enough to leave detectable signals

  13. Ancient and contemporary DNA reveal a pre-human decline but no population bottleneck associated with recent human persecution in the kea (Nestor notabilis).

    Science.gov (United States)

    Dussex, Nicolas; Rawlence, Nicolas J; Robertson, Bruce C

    2015-01-01

    The impact of population bottlenecks is an important factor to consider when assessing species survival. Population declines can considerably limit the evolutionary potential of species and make them more susceptible to stochastic events. New Zealand has a well documented history of decline of endemic avifauna related to human colonization. Here, we investigate the genetic effects of a recent population decline in the endangered kea (Nestor notabilis). Kea have undergone a long-lasting persecution between the late 1800s to 1970s where an estimated 150,000 kea were culled under a governmental bounty scheme. Kea now number 1,000-5,000 individuals in the wild and it is likely that the recent population decline may have reduced the genetic diversity of the species. Comparison of contemporary (n = 410), historical (n = 15) and fossil samples (n = 4) showed a loss of mitochondrial diversity since the end of the last glaciation (Otiran Glacial) but no loss of overall genetic diversity associated with the cull. Microsatellite data indicated a recent bottleneck for only one population and a range-wide decline in Ne dating back some 300 - 6,000 years ago, a period predating European arrival in NZ. These results suggest that despite a recent human persecution, kea might have experienced a large population decline before stabilizing in numbers prior to human settlement of New Zealand in response to Holocene changes in habitat distribution. Our study therefore highlights the need to understand the respective effects of climate change and human activities on endangered species dynamics when proposing conservation guidelines. PMID:25719752

  14. Ancient and contemporary DNA reveal a pre-human decline but no population bottleneck associated with recent human persecution in the kea (Nestor notabilis.

    Directory of Open Access Journals (Sweden)

    Nicolas Dussex

    Full Text Available The impact of population bottlenecks is an important factor to consider when assessing species survival. Population declines can considerably limit the evolutionary potential of species and make them more susceptible to stochastic events. New Zealand has a well documented history of decline of endemic avifauna related to human colonization. Here, we investigate the genetic effects of a recent population decline in the endangered kea (Nestor notabilis. Kea have undergone a long-lasting persecution between the late 1800s to 1970s where an estimated 150,000 kea were culled under a governmental bounty scheme. Kea now number 1,000-5,000 individuals in the wild and it is likely that the recent population decline may have reduced the genetic diversity of the species. Comparison of contemporary (n = 410, historical (n = 15 and fossil samples (n = 4 showed a loss of mitochondrial diversity since the end of the last glaciation (Otiran Glacial but no loss of overall genetic diversity associated with the cull. Microsatellite data indicated a recent bottleneck for only one population and a range-wide decline in Ne dating back some 300 - 6,000 years ago, a period predating European arrival in NZ. These results suggest that despite a recent human persecution, kea might have experienced a large population decline before stabilizing in numbers prior to human settlement of New Zealand in response to Holocene changes in habitat distribution. Our study therefore highlights the need to understand the respective effects of climate change and human activities on endangered species dynamics when proposing conservation guidelines.

  15. Genetic Signatures of Demographic Changes in an Avian Top Predator during the Last Century: Bottlenecks and Expansions of the Eurasian Eagle Owl in the Iberian Peninsula.

    Science.gov (United States)

    Graciá, Eva; Ortego, Joaquín; Godoy, José Antonio; Pérez-García, Juan Manuel; Blanco, Guillermo; Delgado, María del Mar; Penteriani, Vincenzo; Almodóvar, Irene; Botella, Francisco; Sánchez-Zapata, José Antonio

    2015-01-01

    The study of the demographic history of species can help to understand the negative impact of recent population declines in organisms of conservation concern. Here, we use neutral molecular markers to explore the genetic consequences of the recent population decline and posterior recovery of the Eurasian eagle owl (Bubo bubo) in the Iberian Peninsula. During the last century, the species was the object of extermination programs, suffering direct persecution by hunters until the 70's. Moreover, during the last decades the eagle owl was severely impacted by increased mortality due to electrocution and the decline of its main prey species, the European rabbit (Oryctolagus cuniculus). In recent times, the decrease of direct persecution and the implementation of some conservation schemes have allowed the species' demographic recovery. Yet, it remains unknown to which extent the past population decline and the later expansion have influenced the current species' pattern of genetic diversity. We used eight microsatellite markers to genotype 235 eagle owls from ten Spanish subpopulations and analyse the presence of genetic signatures attributable to the recent population fluctuations experienced by the species. We found moderate levels of differentiation among the studied subpopulations and Bayesian analyses revealed the existence of three genetic clusters that grouped subpopulations from central, south-western and south-eastern Spain. The observed genetic structure could have resulted from recent human-induced population fragmentation, a patchy distribution of prey populations and/or the philopatric behaviour and habitat selection of the species. We detected an old population bottleneck, which occurred approximately 10,000 years ago, and significant signatures of recent demographic expansions. However, we did not find genetic signatures for a recent bottleneck, which may indicate that population declines were not severe enough to leave detectable signals on the species

  16. 基于TOC和OTE的生产瓶颈识别与优化%Optimization and detection of bottleneck in production based on TOC and OTE

    Institute of Scientific and Technical Information of China (English)

    於骞; 金士良; 何文中

    2011-01-01

    TOC思想即约束理论是平衡生产线的一个重要工具,它告诉我们可以通过查询瓶颈以及经过利用资源消除瓶颈来达到生产线平衡;而OTE是生产线产能的一种量化指标,而这种生产线指的是具有多台设备联系在一起的生产流程.在介绍TOC思想和OTE计算公式的基础上,利用Witness仿真软件对生产系统建模与仿真,结合TOC和OTE来识别在不同需求下的生产系统瓶颈,提出解决瓶颈的优化方案,改进生产系统,在考虑成本的情况下增加整个系统合格产出,以及提高整个系统的产能.%TOC is a important tool for making the production line balance,we can use TOC to find bottleneck and undo the it by every resource we have ;OTE is metric for capacity of line which has many series machines.With the idea of TOC and the calculation of OTE, It will put forward modeling and simulat-ing of manufacturing system by using witness,detecting bottleneck in line on different market demand, proposing the optimal solution and improving the system in enhancing the qualified output as will as pro-duction capacity in considering cost which are all based on combination of TOC and OTE.

  17. Correction: Forrester, N.L.; Coffey, L.L.; Weaver, S.C. Arboviral Bottlenecks and Challenges to Maintaining Diversity and Fitness during Mosquito Transmission. Viruses 2014, 6, 3991–4004

    Directory of Open Access Journals (Sweden)

    Naomi L. Forrester

    2014-11-01

    Full Text Available In the original manuscript, Forrester, N.L.; Coffey, L.L.; Weaver, S.C. Arboviral Bottlenecks and Challenges to Maintaining Diversity and Fitness during Mosquito Transmission. Viruses 2014, 6, 3991–4004, Figure 1 contains an error, the third bottle was absent from the figure:[...

  18. 从微信收费之争看瓶颈垄断的反垄断法规制%Discussing the Bottleneck Monopoly Antitrust Regulation Viewing from the Dispute of the Micro-channel Charge

    Institute of Scientific and Technical Information of China (English)

    张积储

    2013-01-01

    Recently , the "micro-channel charge dispute"between three major telecom operators and Tencent set off a wave of the Internet economy monopoly .In the network economy era , the bottleneck monopoly of the economy is becoming more and more , China's "anti-monopoly law"should make corresponding regulations aganist the bottle-neck monopoly , standardize the market behavior of dominant companies .This study takes the dispute of micro-channel charge as clues to introduce the concept of monopoly bottlenecks , analyzes the regulation against the bottle-neck monopoly , highlights the necessity of regulation .Finally, some legislation recommandations are proposed for regulating the bottleneck monopoly .%日前,电信三大运营商与腾讯的“微信收费之争”掀起了网络经济的垄断浪潮。在网络经济的时代下,瓶颈垄断经济越来越多,我国《反垄断法》应该对这种瓶颈垄断行为作出相应的规定,规范优势企业的市场行为。将以微信收费的争端为线索,引出瓶颈垄断的概念,浅析我国垄断法对瓶颈垄断的规制,突出瓶颈垄断行为应受规制的必要性,并提出瓶颈垄断反垄断法规制的立法建议。

  19. Empirical Study for Improving the Traffic Conditions at Bottleneck Road Sections%瓶颈路段交通改善实证研究

    Institute of Scientific and Technical Information of China (English)

    李妙君; 孙全欣; 杨静

    2011-01-01

    城市道路路网中,瓶颈路段的存在对路网通行能力有显著的影响.本文归纳了瓶颈路段存在的两类常见问题:由于拆迁、开发遗留等造成的瓶颈路拥堵;以及铁路、桥等阻碍造成的瓶颈路拥堵.对断头路、瓶颈路的改善措施进行了梳理.结合姚家园路区域-朝阳公园桥案例展开了实证研究,研究表明,断头路的存在对路网的通达性有明显影响;合理调节支路的分流量,可以减轻路网节点的拥堵程度;打通断头路,路网的非直线系数提高,更加方便路网中节点的交流;畸形交叉口的改善,使路网的连接度提高17.5%.%The road sections as bottlenecks of a road network decrease the traffic capacity of the road network significantly.The reasons for making bottleneck road sections are summarized in this study.They include the bad planning of the urban roads in the process of urban development and the influence from the railway lines and bridges in the urban areas.Based on the study of the Chaoyang Park Bridge around Yaojiayuan Road, it is proved that break road sections have a significant impact on the capacity of the road network and sharing part of the traffic volume on arterial roads to branch roads can release the congestion level at the nodes the road network.Smoothing break road sections can increase the value of the non-linear coefficient of the road network and make the connections between the nodes of the road network more easily.Moreover, improving the traffic conditions at intersections whose configurations are irregular can increase the accessibility of the road network by 17.5%.

  20. Method and Application of Manufacturing Industry Breaking Inventory Management Bottleneck%制造业突破库存管理瓶颈的方法及应用

    Institute of Scientific and Technical Information of China (English)

    董鹏; 郭丽美; 荆一帆

    2013-01-01

    The authors analyse the bottleneck of traditional inventory management and relative view points of inven-tory management, and find out the reason of inventory backlog of Carlisle company finished products and its bad in-fluence on enterprises. Combined with the example of Carlisle company to reduce the inventory backlog, they point out that the application of management tools, such as objectives management, fishbone diagram, ABC classification, is the most effective method to reduce the inventory backlog. This can provide reference to related manufacturing in-dustry for effective inventory management.%  分析传统库存管理的瓶颈及库存管理的相关观点,找出卡莱公司造成成品库存积压的原因及带来的不良影响;结合卡莱公司降低库存的实例,指出运用目标管理、鱼骨图、ABC分类等管理工具,是降低库存的最有效方法,为相关制造业进行有效的库存管理提供借鉴。

  1. Genetic Variability of Bovine Viral Diarrhea Virus and Evidence for a Possible Genetic Bottleneck during Vertical Transmission in Persistently Infected Cattle.

    Science.gov (United States)

    Dow, Natalie; Chernick, Adam; Orsel, Karin; van Marle, Guido; van der Meer, Frank

    2015-01-01

    Bovine viral diarrhea virus (BVDV), a Pestivirus in the family Flaviviridae, is an economically important pathogen of cattle worldwide. The primary propagators of the virus are immunotolerant persistently infected (PI) cattle, which shed large quantities of virus throughout life. Despite the absence of an acquired immunity against BVDV in these PI cattle there are strong indications of viral variability that are of clinical and epidemiological importance. In this study the variability of E2 and NS5B sequences in multiple body compartments of PI cattle were characterized using clonal sequencing. Phylogenetic analyses revealed that BVDV exists as a quasispecies within PI cattle. Viral variants were clustered by tissue compartment significantly more often than expected by chance alone with the central nervous system appearing to be a particularly important viral reservoir. We also found strong indications for a genetic bottleneck during vertical transmission from PI animals to their offspring. These quasispecies analyses within PI cattle exemplify the role of the PI host in viral propagation and highlight the complex dynamics of BVDV pathogenesis, transmission and evolution.

  2. 物联网产业发展现状及瓶颈研究%Status Quo and Development Bottleneck of Internet of Things

    Institute of Scientific and Technical Information of China (English)

    刘勇燕; 郭丽峰

    2012-01-01

    物联网产业是当前重大战略性新型产业之一,是后金融危机时代推进产业结构升级、提升信息产业发展的基础和形势.在对物联网产业的内涵、体系结构进行系统阐述和分析基础上,基于当前物联网产业发展的基础和形势,重点分析了物联网产业发展过程中在标准规范、核心技术、稀缺资源、信息安全、知识产权保护等方面亟待研究和解决的瓶颈问题.%Internet of things is one of significant strategic emerging industries, is the engine for industry structure promotion in postfinancial-crisis era. This article illustrates the concept and architecture of Internet of things, and analyzes bottleneck problems on standards, core technology, scarce resources, information security and intellectual property protection in the development of this industry.

  3. The Mouse-colored Tyrannulet (Phaeomyias murina) is a species complex that includes the Cocos Flycatcher (Nesotriccus ridgwayi), an island form that underwent a population bottleneck.

    Science.gov (United States)

    Zucker, Marc R; Harvey, Michael G; Oswald, Jessica A; Cuervo, Andrés; Derryberry, Elizabeth; Brumfield, Robb T

    2016-08-01

    Simultaneous examination of evolutionary history in island forms and closely related mainland relatives can provide reciprocal insight into the evolution of island and mainland faunas. The Cocos Flycatcher (Nesotriccus ridgwayi) is a small tyrant flycatcher (Tyrannidae) endemic to Cocos Island, an oceanic island in the eastern Pacific Ocean. We first established its close relationship to the mainland species Mouse-colored Tyrannulet (Phaeomyias murina) using a phylogeny from genome-wide ultraconserved elements and exons. We then used mitochondrial DNA to explore the relationships between Nesotriccus and Phaeomyias populations from across its distribution in Central and South America. We found that Nesotriccus is nested within the Phaeomyias evolutionary tree, and that Phaeomyias represents a complex of at least four evolutionarily distinct species that differ in plumage, voice, and habitat association. Nesotriccus underwent a population bottleneck subsequent to its divergence from Central American and northern South American Phaeomyias populations in the middle Pleistocene. The 46 UCE loci containing alleles that are fixed between the two species are widely distributed across the genome, which suggests that selective or neutral processes responsible for divergence have occurred genome-wide. Overall, our simultaneous examination of Phaeomyias and Nesotriccus revealed divergent levels of genetic diversity and evolutionary histories between island and mainland forms. PMID:27126184

  4. Genetic Variability of Bovine Viral Diarrhea Virus and Evidence for a Possible Genetic Bottleneck during Vertical Transmission in Persistently Infected Cattle.

    Directory of Open Access Journals (Sweden)

    Natalie Dow

    Full Text Available Bovine viral diarrhea virus (BVDV, a Pestivirus in the family Flaviviridae, is an economically important pathogen of cattle worldwide. The primary propagators of the virus are immunotolerant persistently infected (PI cattle, which shed large quantities of virus throughout life. Despite the absence of an acquired immunity against BVDV in these PI cattle there are strong indications of viral variability that are of clinical and epidemiological importance. In this study the variability of E2 and NS5B sequences in multiple body compartments of PI cattle were characterized using clonal sequencing. Phylogenetic analyses revealed that BVDV exists as a quasispecies within PI cattle. Viral variants were clustered by tissue compartment significantly more often than expected by chance alone with the central nervous system appearing to be a particularly important viral reservoir. We also found strong indications for a genetic bottleneck during vertical transmission from PI animals to their offspring. These quasispecies analyses within PI cattle exemplify the role of the PI host in viral propagation and highlight the complex dynamics of BVDV pathogenesis, transmission and evolution.

  5. Time-Lapse Analysis of Human Embryonic Stem Cells Reveals Multiple Bottlenecks Restricting Colony Formation and Their Relief upon Culture Adaptation

    Directory of Open Access Journals (Sweden)

    Ivana Barbaric

    2014-07-01

    Full Text Available Using time-lapse imaging, we have identified a series of bottlenecks that restrict growth of early-passage human embryonic stem cells (hESCs and that are relieved by karyotypically abnormal variants that are selected by prolonged culture. Only a minority of karyotypically normal cells divided after plating, and these were mainly cells in the later stages of cell cycle at the time of plating. Furthermore, the daughter cells showed a continued pattern of cell death after division, so that few formed long-term proliferating colonies. These colony-forming cells showed distinct patterns of cell movement. Increasing cell density enhanced cell movement facilitating cell:cell contact, which resulted in increased proportion of dividing cells and improved survival postplating of normal hESCs. In contrast, most of the karyotypically abnormal cells reentered the cell cycle on plating and gave rise to healthy progeny, without the need for cell:cell contacts and independent of their motility patterns.

  6. Study on due-time bottleneck identification in job shop based on fuzzy inference system%基于模糊推理系统的作业车间交货期瓶颈辨识研究

    Institute of Scientific and Technical Information of China (English)

    顾余容; 鲁建厦; 詹燕

    2011-01-01

    Aiming at the rising problem of poor due-time satisfaction in current manufacturing industry, the importance and urgency of the study on due-time bottleneck is described. A fuzzy inference system is employed to define due-time bottleneck. The identification method of due-time bottleneck job in different processing stage is proposed and the identification model of due-time bottleneck in job shop is established. The identification method based on fuzzy inference system is convenient to be practically applied and also suitable to be employed to simulate by computer software. The example concerning a workshop proves the feasibility of the model and method.%针对现今制造企业的客户交货期满意度低的问题,阐述了研究交货期瓶颈问题的重要性和紧迫性.通过应用模糊推理系统知识来定义交货期瓶颈,提出了辨识不同加工阶段的交货期瓶颈工件的方法,建立了作业车间生产系统的交货期瓶颈辨识模型.基于模糊推理系统的辨识方法操作方便,便于用计算机软件实现.最后,应用某加工车间的实例说明了该辨识方法的有效性.

  7. 基于定点数据的道路瓶颈拥挤自动识别算法%Automatic Identification Algorithm for Road Bottlenecks Based on Detector Data

    Institute of Scientific and Technical Information of China (English)

    弓晋丽; 彭贤武

    2013-01-01

    为研究道路瓶颈处的交通拥挤现象,掌握由道路瓶颈引发的常发性拥挤的分布特点和变化规律,提出了道路瓶颈拥挤的自动识别算法.基于检测线圈历史数据,将交通状态定性划分为畅通和拥挤2种,根据瓶颈拥挤原理,识别道路瓶颈所在,并同时对由其引发的拥挤持续时长和拥挤范围进行鉴别.算法运算结果包含瓶颈定位及由其引发的拥挤持续时长和空间影响范围.以上海市南北高架路东侧10 d线圈检测数据为例,验证了算法的有效性和实用性.%To study the problem of traffic congestion at road bottlenecks and know the distribution properties as to change regulation of the Recurrent Congestion, a new automatic identification algorithm for road bottlenecks was proposed. Based on historical traffic data from the dual-loop detectors on road, the algorithm differentiates uncongested traffic state from congested state, thereby identifying traffic bottlenecks according to principle of congestion. It will also compute the congestion duration and influence range caused by bottlenecks at the same time. By using field data from dual-loop detectors on Shanghai North-South elevated road for 10 days, the effectiveness and practicality of the algorithm have been verified.

  8. Time-varying Material Distribution Routing Optimization Considering Shifting Bottleneck%计及漂移瓶颈的时变物料配送路径优化

    Institute of Scientific and Technical Information of China (English)

    凌琳; 刘明周; 葛茂根; 王强; 马靖

    2015-01-01

    Aiming at the material distribution routing optimization problem under uncertain job shop environment, the bottleneck index and bottleneck shifting index which represent the relative production load of each manufacturing unit and its the change trend are adopted to denote the time-varying distribution priority of the manufacturing unit. Then the time-varying material distribution routing optimization models are established and its objective is minimizing the distribution cost including vehicle transportation cost and punishment cost due to the violation of distribution priority. Based on that, suppose the condition that the vehicle haven't to be loaded fully and material can be distributed to one manufacturing more times in order to guarantee that the material in the vehicle is distributed totally before the vehicle comes back to the distribution center and to avoid unnecessary distribution sub-route, then propose the modified time-varying material distribution routing optimization model to enhance the distribution productivity and decrease the distribution cost further. The greedy-based genetic algorithm is presented to solve the proposed optimization model. An example of some job shop material distribution routing optimization is given to prove the validation and practicability of the proposed method under uncertainty.%针对不确定作业车间环境下物料配送路径优化问题,采用能反映制造单元相对生产负荷及其变化趋势的瓶颈指数和瓶颈漂移指数表征实时变化的制造单元物料配送优先级,对路径选择过程中违反此优先级的行为设置惩罚成本,提出以最小化包括车辆运输成本和违反优先级的惩罚成本在内的总配送成本为优化目标,建立了时变的物料配送路径优化模型.在此基础上,为保证运输车辆所载物料全额配送,避免非必要负载以及由此造成的非必要配送子路径,对配送路径优化模型进行改进,允许运输车辆非满载和

  9. 发展大学生领导力教育的瓶颈及对策%The Bottlenecks and Countermeasures on the Leadership Education of College Students

    Institute of Scientific and Technical Information of China (English)

    张恒龙; 张书磊

    2012-01-01

    世界各国的经验表明,高校开展大学生领导力教育有利于大学生更好地适应未来不断变化发展的现代社会。近些年,我国也开始关注大学生领导力教育问题,但在发展大学生领导力教育过程中存在定位有失偏颇、理解不够全面、教育资源的开发与利用不足等三大瓶颈。为此,对大学生领导力教育进行恰当定位,从大学生成长成才的角度出发开展领导力教育。探索大学生领导力教育长效机制显得十分紧迫和必要。%The experience of leadership education for college students around the world shows that it's helpful for them to better adapt to the changing modem society. Recently more and more universities have launched some projects of leadership education for college students in China, but in the process there are three bottlenecks. One is that many people haven't realized the importance of leadership education for college students; the second is that people haven't fully understood the conception; the third is that the form of leadership education is not rich. Therefore, we should correct the position of leadership education for coil perspective of comprehensive development, and explore the education. lasting ege students, develop leadership from the effect mechanism of student leadership education.

  10. 突破初中英语写作瓶颈的策略分析%Strategies to Break the Bottleneck of Junior High School English Writing

    Institute of Scientific and Technical Information of China (English)

    邓剑昆

    2014-01-01

    English learning includes listening, speaking, reading and writing four parts, in junior high school English teach-ing, teaching writing is an important and indispensable component. The vocabulary of English composition, structure, gram-mar, etc. in one set, writing instruction can promote students' comprehensive ability to use language. However, the current situation is not optimistic teaching junior high school English writing;students learn English writing is not only weak link, but also one of the bottlenecks in the teaching of English teachers. Therefore, this article is for junior high school English Writing discuss the problems in the analysis, put forward some writing teaching measures to improve the quality of teaching and promoting junior high school English writing skills.%英语学习包括了听、说、读、写四个部分,在初中英语教学中,写作教学是不可缺少的重要组成部分。英语作文将词汇、结构、语法等集于一体,写作教学能够促进学生综合语言运用能力。但是,初中英语写作教学现状不容乐观,英语写作不仅是学生学习的薄弱环节,同时也是英语教师在教学中的瓶颈之一。因此,本文就针对初中英语写作教学中存在的问题进行探讨分析,提出了一些写作教学措施,从而提高教学质量,促进初中生英语写作水平。

  11. The Bottleneck and Breakthrough in Telecom Fraud Investigation%电信诈骗犯罪侦查的瓶颈及其突破

    Institute of Scientific and Technical Information of China (English)

    杨郁娟

    2015-01-01

    The bottleneck of telecom fraud investiga tion mainly existed in the scene, case-combining and collaboration investigation. The scene investigation for the telecom fraud and its content are different with the others, in which we must focus on discovering, fixing and extracting the electronic data and interrogate suspects in time. In case-combing investigation, there are problems of the negative attitude and the insufficient accordance. In which we must regulate it through the information construction. In the collaborative investigation, many departments and external organs might be involved besides the public security normal collaboration, namely as collaboration with banks and international cooperation.%电信诈骗犯罪侦查瓶颈主要存在于现场勘查、并案侦查、侦查协作等环节。电信诈骗犯罪现场勘查的地位及其内容等与其他犯罪现场勘查有所不同,应注重电子数据的发现、固定和提取,将现场勘查与即时讯问犯罪嫌疑人密切结合;电信诈骗犯罪并案侦查存在并案不积极和并案依据较少的问题,应通过信息化建设将电信诈骗犯罪并案侦查纳入规范化轨道;在侦查协作方面,除了公安机关内部的常规协作外,更多的是要加强侦查部门与外部机构的协作,即公安机关与银行的协作以及国际警务合作。

  12. Phylogeography of postglacial range expansion in Juglans mandshurica (Juglandaceae) reveals no evidence of bottleneck, loss of genetic diversity, or isolation by distance in the leading-edge populations.

    Science.gov (United States)

    Wang, Wen-Ting; Xu, Bing; Zhang, Da-Yong; Bai, Wei-Ning

    2016-09-01

    The past studies of postglacial recolonization patterns in high latitude regions have revealed a significant role of dispersal capacity in shaping the genetic diversity and population structure of temperate trees. However, most of these studies have focused on species with long-distance dispersal followed by exponential population growth and were therefore unable to reveal the patterns in the case of a gradual expansion. Here we studied the impacts of postglacial range expansions on the distribution of genetic diversity in the Manchurian walnut (Juglans mandshurica), a common tree of East Asian cool-temperate deciduous forests that apparently lacks long-distance seed dispersal ability. The genetic diversity and structure of 19 natural walnut populations in Northeast China and the Korean Peninsula were examined using 17 nuclear simple sequence repeat (SSR) loci. Potential habitats under current and past climatic conditions were predicted using the ecological niche modelling (ENM) method. Bayesian clustering analysis revealed three groups, which were inferred to have diverged through multiple glacial-interglacial cycles in multiple refugia during the Quaternary Period. ENM estimated a southward range shift at the LGM, but high suitability scores still occurred in the western parts of the Changbai Mountains (Northeast China), the Korean peninsula and the exposed seafloor of the Yellow Sea. In contrast to most other cool-temperate trees co-occurring in the same region, the Manchurian walnut did not show any evidence of a population bottleneck, loss of genetic diversity or isolation by distance during the postglacial expansion. Our study clearly indicates that current northern populations originated from one glacial lineage and recolonization via a gradually advancing front due to the lack of a long-distance seed dispersal mechanism led to no latitudinal decrease in genetic diversity. PMID:27346642

  13. Phylogeography of postglacial range expansion in Juglans mandshurica (Juglandaceae) reveals no evidence of bottleneck, loss of genetic diversity, or isolation by distance in the leading-edge populations.

    Science.gov (United States)

    Wang, Wen-Ting; Xu, Bing; Zhang, Da-Yong; Bai, Wei-Ning

    2016-09-01

    The past studies of postglacial recolonization patterns in high latitude regions have revealed a significant role of dispersal capacity in shaping the genetic diversity and population structure of temperate trees. However, most of these studies have focused on species with long-distance dispersal followed by exponential population growth and were therefore unable to reveal the patterns in the case of a gradual expansion. Here we studied the impacts of postglacial range expansions on the distribution of genetic diversity in the Manchurian walnut (Juglans mandshurica), a common tree of East Asian cool-temperate deciduous forests that apparently lacks long-distance seed dispersal ability. The genetic diversity and structure of 19 natural walnut populations in Northeast China and the Korean Peninsula were examined using 17 nuclear simple sequence repeat (SSR) loci. Potential habitats under current and past climatic conditions were predicted using the ecological niche modelling (ENM) method. Bayesian clustering analysis revealed three groups, which were inferred to have diverged through multiple glacial-interglacial cycles in multiple refugia during the Quaternary Period. ENM estimated a southward range shift at the LGM, but high suitability scores still occurred in the western parts of the Changbai Mountains (Northeast China), the Korean peninsula and the exposed seafloor of the Yellow Sea. In contrast to most other cool-temperate trees co-occurring in the same region, the Manchurian walnut did not show any evidence of a population bottleneck, loss of genetic diversity or isolation by distance during the postglacial expansion. Our study clearly indicates that current northern populations originated from one glacial lineage and recolonization via a gradually advancing front due to the lack of a long-distance seed dispersal mechanism led to no latitudinal decrease in genetic diversity.

  14. Progress and Yield Bottleneck of Aerobic Rice in the North China Plain: A Case Study of Varieties Handao 297 and Handao 502

    Institute of Scientific and Technical Information of China (English)

    XIE Guang-hui; YU Jun; WANG Hua-qi; BAM Bouman

    2008-01-01

    Aerobic rice has been considered a promising rice cultivation system as water scarcity is increasing in the world. This article summarizes the advances in aerobic rice management researches in the North China Plain, focusing on yield formation and its bottleneck. High-yielding and good-quality aerobic rice varieties adapted to aerobic soil conditions have been released officially and adopted by farmers in North China. The varieties Handao 502 and Handao 297 have been recognized as the most promising varieties reaching a yield level ranging 3.5-5.0t ha-1 with 450-650mm water input. Compared with lowland rice, water input in aerobic rice was more than 50% lower, and water productivity was 60% higher. Researches on responses of rice cultivars to nitrate nitrogen (N) and ammonium N supplied at early growth stages provided the first evidence for a preference of aerobic rice HD 297 for nitrate N supply, compared with the lowland rice variety. Zinc uptake studies demonstrated that introduction of aerobic rice system on calcareous soils may increase zinc deficiency problems. Sink size was identified as the limitation of aerobic rice yield, because its spikelet number m-2 was too low (20000-24000) compared with the lowland rice. For future research, more attention is suggested to be paid to yield formation focusing on effects of water regimes on tiller dynamics. Understanding of nutrient uptake and response to fertilization effects are also urgently required to establish optimized crop management technology. Additionally, alternative cropping systems based on aerobic rice should be established, and key sustainability and environmental impact issues in the systems need to be identified.

  15. Pompen zijn vaak de bottleneck

    NARCIS (Netherlands)

    Wit-Blok, M. de

    2014-01-01

    Leon Geers, senior research scientist bij TNO Process & Instrumentation Development: “Met het verbeteren van de beheersbaarheid en efficiëntie van de processen zijn er nieuwe ‘zwakste schakels’ ontstaan. Eén daarvan vormen pompen.

  16. Signal Control Strategies for Bottleneck Area on Urban Expressway%城市快速路瓶颈区域控制策略研究

    Institute of Scientific and Technical Information of China (English)

    尹胜超; 许润民; 张毅; 李志恒

    2012-01-01

    Urban expressways in China have special features. Distance between on-ramp and off-ramp is relatively shorter compared with tins that in developed countries ( normally longer than 1000 m) , off-ramps are usually connected with urban streets and intersections. Thus successful ramp control strategies used in Europe or U.S. may not be suitable in China. First, this paper studies traffic flow characteristics at several representative "bottlenecks" in Beijing urban expressways. Efforts are devoted to improve the capability of traffic simulation platform to simulate detailed traffic behaviours by calibrating simulation model parameters. Efficiencies of different signal control strategies in road network involving on-ramp, off-ramp, adjacent streets and intersections are compared. Results indicate that combing adaptive ramp control with Synchronization signal control strategies is an efficient way to enhance road capacity and alleviate congestions for urban expressways.%中国的城市快速路与发达国家相比有着截然不同的特征.中国城市快速路匝道出入口之间距离相对较短,且城市快速路匝道出口经常与城市道路交叉口相连,因此在欧美成功应用的快速路匝道控制方案不一定适用于中国.本文详细描述了如何在仿真中设置模型参数,使得城市快速路交通流特性仿真结果与实际测量值具有较高的匹配精度.在具体阐述自适应与协同信号控制策略的基础之上,给出了各种方案在匝道入口、出口辅路和出口下游交叉口的具体部署方案.最终仿真结果表明,自适应和协同控制策略能够提高瓶颈区域道路通行能力8% -9%,有效地缓解城市快速路交通拥堵.

  17. 基于增长修剪型神经网络的半导体生产线动态瓶颈分析方法%Dyna mic Bottleneck Analysis for Se miconductor Wafer Fabrication Syste m Based on Growing and Pru ning Neu ral Networks

    Institute of Scientific and Technical Information of China (English)

    曹政才; 邱明辉; 刘民

    2016-01-01

    Bottleneck is the key factor to semiconductor wafer fabrication system (SWFS),which seriously influ-ences the level of work-in-process,cycle time,time-delivery rate,etc.Efficient analysis for the bottleneck of SWFS can pro-mote various performances.In modern SWFS,present analysis methods usually regard bottleneck device as static bottleneck without taking bottleneck shifting into consideration in the uncertain environment,which leads to scheduling algorithm that always treat the bottleneck device as the core lack of flexibility and real-time performance.Therefore,dynamic bottleneck a-nalysis method for the SWFS based on growing and pruning neural networks (GPNN)was adopted in this study to acquire the dynamic bottleneck characteristic.Firstly,in this paper,the way of composite definition is used to calculate comprehen-sive bottleneck degree of the devices form the perspectives of relative production load,utilization rate and length of the buffer queue to indicate bottleneck based on bottleneck identification mechanism;Secondly,establish the model of growing and pruning neural networks to predict the future bottleneck and adjust the network structure in view of closed-loop control. Thirdly,in order to analyze the key factors relative to bottleneck devices and the dynamic bottleneck characteristic quantita-tively,the single factor test method was applied in this paper.Lastly,the experiments show that this dynamic bottleneck anal-ysis method is testified the feasibility and availability.%瓶颈设备是制约半导体生产线在制品水平、生产周期及准时交货率的关键因素,对其进行有效地分析能够提高生产线多性能。现有的分析方法主要是将瓶颈设备视为静态瓶颈,未考虑到生产线不确定因素所带来的动态漂移问题,这样容易造成以瓶颈设备控制为核心的调度算法缺乏柔性,降低算法实效性,因此,本文提出一种基于增长修剪型神经网络的动

  18. Study on Identification and Optimization of Bottlenecks in Production Logistics Processes Based on Queue Network Theory%基于排队网络理论的生产物流瓶颈识别与优化研究

    Institute of Scientific and Technical Information of China (English)

    张仕军

    2014-01-01

    针对制造系统多品种小批量生产模式下物流瓶颈转移的复杂问题,在对排队网络理论进行深入研究的基础上,建立了不同工站利用率和生产负荷的关系,并针对两类工件和四个工站的排队网络,对生产物流瓶颈转移趋势进行了分析,提出了用MVA近似分析法推算生产物流瓶颈的方法,该方法可以较好地计算瓶颈转折点的数值,能够有效处理生产物流瓶颈转移问题,为提高制造企业生产物流瓶颈管理水平创造了条件。%In this paper, in view of the complexity in removing the logistics bottlenecks in the multi-variety small-batch production system and on the basis of an in-depth analysis of the queue network theory, we established the relationship between the production load and utility rate of different workstations, then in view of the queue network involving two types of work pieces and four workstations, analyzed the trend of the relocation of the bottlenecks in the production logistics system and at last proposed the MVA method to deduct the bottleneck removing process.

  19. 休闲足球运动发展瓶颈问题与对策研究%Research on Developing Bottlenecks and Strategies of Leisure Football

    Institute of Scientific and Technical Information of China (English)

    郑萌

    2015-01-01

    In order to help China’s leisure football develop better, using researching methods including literature and logical analysis, combining with nation environment analysis, sums out the 4 holding back bottlenecks impeding China’s leisure football’s development including limited average resources possession, high threshold of activity participation, social culture value contradiction, insufficient humanity meaning excavation, which causes the prominent problem of low satisfaction of participants’ demands. Comes up with the 2 countermeasures of: to promote school and social education and cultivation to guide and change social culture and demands; to optimize educating and training concepts and means to meet real national environment and social demands. Then implies that the most effective way to guide and change social culture and demands is education and cultivation including: school education and cultivation which mainly run by government administration; social education and cultivation which mainly run by enterprises and markets. This article also implies that the 2 critical points of optimizing educating and training concepts: to optimize teaching methods of techniques and tactics, and to reinforce the excavation of culture connotation. And that the core of optimize educating and training means is to introduce promote modern educating techniques represented by e-educating.%为更好推动我国休闲足球运动发展,运用文献资料、逻辑分析等研究方法,结合国情环境分析,归纳出制约休闲足球运动发展的社会文化价值取向冲突、人文内涵挖掘不足、人均资源占有少、运动参与门槛高等制约瓶颈和由此导致的参与者需求满足能力低等突出问题,提出突破休闲足球运动发展制约瓶颈、解决休闲足球运动发展所面临突出问题的两大对策:推广学校、社会教育培训,引导改变社会文化和需求;改进教育训练理念、手段,适应国情

  20. 探究式教学在高职体育教学中的发展瓶颈与对策%Development Bottlenecks of Inquiry-based Teaching in Higher Vocational PE Teaching and the Countermeasures

    Institute of Scientific and Technical Information of China (English)

    王华

    2012-01-01

    In this paper, through research methods, such as data method, interview method and logic reasoning method and so on, to study the problems exist in inquiry-based teaching, the bottlenecks of applied development of inquiry-based teaching in higher vocational physical education were found. In order to overcome these development bottlenecks, education authorities, schools and teachers should constantly plan new teaching materials, enhance teachers' training, improve the status of physical education and reform the evaluation methods etc.%本文通过资料法、访谈法、逻辑推理法等研究方法,对探究式教学存在的问题进行研究,发现了探究式教学在高职体育课中应用发展的瓶颈,要克服这些发展瓶颈,就需要教育主管部门、学校、教师不断地规划新教材、加强教师培训、提升体育课地位、改革评价方式等.

  1. 广场舞对老年人生活质量的影响与发展瓶颈%A research on the square dance’influence to the old people’s life quality and its bottleneck of development

    Institute of Scientific and Technical Information of China (English)

    邹荣霞; 陈军

    2015-01-01

    对广场舞特点和其产生的影响与发展瓶颈进行分析,建议政府应关心、重视老年人体育文化生活,尽力解决制约广场舞发展的瓶颈;学校和媒体应积极参与,加强社会各界关注,使广场舞健康而快速发展。%The characteristics and the influence of square dance as well as its development bottleneck were described to suggest that the government should take care of and attach importance to sports and cultural life of the elderly,trying to solve the bottleneck restricting the development of square dance. Schools and media should be actively involved in to strengthen the social attention from all walks of life to make the square dance get healthy and rapid development.

  2. 关中地区休闲旅游产业发展的瓶颈与破解∗%On the Development Bottlenecks of Leisure Tourism Industry and Crack Methods in GuanZhong Area of Shanxi Province

    Institute of Scientific and Technical Information of China (English)

    张金凤

    2016-01-01

    s:The leisure and tourism industry in Guanzhong region have related to the development of tourism industry in Guanzhong-Tianshui Economic Zone and Silk Road Economic Belt.However,the devel-opment of tourism industry has been restricted by the main bottleneck in the area.Such as uneven tourism re-sources distribution;poor economic benefit and tourist traffic;insufficient tourism experience;lacking mar-keting and the unknown cultural characteristics.In order to optimize the development of leisure tourism in-dustry in Guanzhong area,it must be broke the bottlenecks from the following five aspects:planning scientif-ically to form large tourism circle;optimizing transportation and construct direct line of tourist;updating ideas to build a well-known tourist brand;breaking the old board to explore global travel patterns;digging the connotation deeply to increase tourism attractions.%关中地区休闲旅游产业的发展关联着关天经济区与丝绸之路经济带的发展。然而旅游资源分布不均、经济效益不佳、旅游体验不足、市场营销不够、旅游交通不畅和文化特色不显是制约关中地区休闲旅游产业发展的主要瓶颈。以科学规划,形成大旅游圈;优化交通,建设旅游直达专线;更新观念,打造知名旅游品牌;打破旧局,探索全域旅游模式;深挖内涵,增加旅游吸引力来破解关中地区休闲旅游产业发展的瓶颈,加快关中地区休闲旅游产业发展。

  3. Bottleneck problems and countermeasures of nursing team construction in the secondary hospitals%影响二级医院护理队伍建设的瓶颈问题及对策

    Institute of Scientific and Technical Information of China (English)

    钟郁鸿

    2015-01-01

    本文分析了影响二级医院护理队伍建设的瓶颈问题,重点提出了以更新观念,稳定护理队伍;优化知识结构,提高护士专业素质;健全科研创新管理机制,提高科研能力;建立竞争机制,营造人才成长的良好氛围;适应护理专业发展,打造临床护理专家队伍的对策措施。%This paper analyzes the bottleneck problems of nursing team construction in level two hospitals and proposes the countermeasures to solve the problems, including updating concepts, stabling nursing team;optimizing the knowledge structure, improving nursing professional quality;improving scientific research and innovation management mechanism, enhancing research capacity;establishing competitive mechanism, creating a good atmosphere for the talent growth;adapting nursing professional development, and building clinical nursing service team.

  4. 同步感应线圈炮的技术瓶颈与应用前景分析研究%Technology Bottleneck and Application Prospect of Synchronous Induction Coil Gun

    Institute of Scientific and Technical Information of China (English)

    向红军; 李治源; 雷彬

    2012-01-01

    The paper introduces the working principle of multistage synchronous inductive coil gun, and analyzes the technology bottleneck of coil gun such as the storage energy miniaturization, position triggering and the lifetime of driving coils. Then it draws the conclusion that the synchronous inductive coil gun is suitable for the low and medium armature velocity launching. Finally, it studies the application prospect of synchronous inductive coil gun in electromagnetic mortar, high mass load ejecting and fuse dynamic experiment, which is useful for the development of the synchronous inductive coil gun in the future.%介绍多级同步感应线圈炮的工作原理,分析目前同步感应线圈炮在储能电源小型化、位置触发及驱动线圈寿命等方面的技术瓶颈,得出同步感应线圈炮更适用于中低初速载荷发射的结论,同时,研究同步感应线圈炮在电磁线圈迫击炮、大质量载荷弹射和引信动态试验等方面的应用前景,为科学制定同步感应线圈炮发展战略奠定了基础.

  5. Research on the Models of College Students Start Their Own Business Under the Bottle-neck Condition%基于瓶颈制约下的大学生创业模式探析

    Institute of Scientific and Technical Information of China (English)

    刘建荣; 于勇

    2009-01-01

    Right now, more and more graduates enter the employment "new blind" ranks because of the current financial crisis. The college students start their own business in China has experienced more than 20 years, its models have been enriched, each model his its own characteristics, has the bottle-neck constraints of the entrepreneurial's thinking, background, ability and something else. This papar introduces several popular models currently, in order to help students choose the fight model at the particular time and across the employment winter, then take the road to entrepreneurial success.%当前的金融危机导致越来越多的大学生步入就业"新盲流"行列.我国大学生创业经历了20多年的发展历程,创业模式也在不断地丰富,每种创业模式形成了各自的特点,但创业模式存在着创业主体思维、背景、能力等方面的制约因素.大学生必须注意创业模式的选择和创业能力的培养.

  6. Real-Time Scheduling of the Bottleneck Workstation for Auto Maintenance Workshop%汽车维修服务站瓶颈工序的实时调度

    Institute of Scientific and Technical Information of China (English)

    杨琴; 周国华; 赵茜; 李艳茹

    2011-01-01

    在结合优化调度理论和约束理论的基础上,从最小化目标、机器环境、加工特征和约束几方面分析了汽车维修服务站瓶颈工序的实时凋度问题的特征,建立了对应的数学模型.根据问题特性,设计了包含复合动态分派规则的启发式调度算法.以实例分析验证了算法的可行性,仿真结果展示了所用算法在优化目标函数值上的优越性和计算时间的可行性.%By using the theory of constraints, real-time scheduling is conducted for a painting workstation,the bottleneck in an automotive maintenance plant. By taking machine environment,processing characteristics,and operation constraints into account, a mathematical model is developed with minimizing the tardiness as objective. Based on the model and due to the complexity of the problem, a heuristic is presented by combining composite dynamic dispatching roles. A case problem is used to verify the application of the proposed method. Numerical results show that it is computationally efficient and good schedules can be obtained.

  7. Operational Bottlenecks and Countermeasures of House Refuse Logistics System in Great Cities of China%我国大城市生活垃圾物流系统运作瓶颈与对策

    Institute of Scientific and Technical Information of China (English)

    赵长东

    2011-01-01

    Along with the acceleration of urbanization and the increase of urban population of our county, house refuse logistics system in many big cities become difficult to satisfied the increasingly requirements of people's living standard. This article starts from the logistics operation processes of the metropolitan house refuse: collection、 classification、 transportation、 terminal treatment to analyze the bottleneck of the whole operation processes of the house refuse logistics system, and raises the countermeasures to build an efficient logistics system of the municipal solid waste based on this.%随着我国城市化进程的加快,城市人口数量的增加,许多大城市的生活垃圾物流系统难以满足日益提高的人民生活水平要求.本丈从大城市生活垃圾物流的运作流程:收集、分类,运输、末端处理分析了整个垃圾物流系统运作流程瓶颈,并据此提出了建立高效的城市生活垃圾物流系统的对策.

  8. 制约体育社会学研究未能继续深入的瓶颈及其对策分析%Analysis on Bottlenecks and Countermeasures of Sports Sociology Unable to Continue in- depth Research

    Institute of Scientific and Technical Information of China (English)

    祁微

    2011-01-01

    From the viewpoint of Statistical data,the author points out that the bottleneck of sports sociology unable to continue in - depth research is the statistical data and the lack of high - quality issues. After interview with some sports sociology experts, statistical experts and social survey experts, the concept of the sports and content of the census is firstly put forward, and the quality of their data for the assessment is rational considered. The main purpose is to promote the sports sociology of scientific research.%从统计数据的视角,笔者认为制约目前体育社会学研究未能继续深入的瓶颈是统计数据问题。笔者在与一部分体育社会学专家、统计学专家和社会调查学专家的交谈后,首次提出了体育普查的概念和内容,并且对其数据质量的评估进行了理性思考,希望籍此提升体育社会学研究的科学性。

  9. 翻转课堂在我国发展的瓶颈及路向选择%The Bottlenecks and Path Alternatives to Flipped Classroom Development in Our Country

    Institute of Scientific and Technical Information of China (English)

    韩丽珍

    2013-01-01

      翻转课堂作为新兴的教育理念及教学模式,为教师提供个性化教学平台,为学生提供个性化学习空间。学生通过课外的自主学习,课内的协作互动,掌握及内化知识。翻转课堂在我国的发展受固有的传统教育文化、教学条件的制约,有必要对其进行本土化改进,寻找适合我国翻转课堂教学的发展路向。通过对翻转课堂的理念及优势进行论述,深入剖析其在我国发展瓶颈,提出翻转课堂在我国的发展路向。%As the emerging philosophy of education and teaching mode , flipped classroom provides personalized teaching platform for teachers and personalized learning space for students .Students acquire and internalize knowledge through extracurricular au-tonomous learning and collaboration in the classroom .The development of the flipped classroom was restricted by the educational culture of inherent tradition and teaching conditions in our country .So it is necessary to make localization improvements and look for suitable direction of development for the flipped classroom teaching in China .After discussing the idea and advantages of the flipped classroom, and analyzing the bottleneck of its development in China , this paper puts forward direction of development of the flipped classroom in our country .

  10. Bottlenecks in the informatization management of small and medium enterprises in Liaoning and solutions%辽宁中小企业信息化管理存在的瓶颈及解决的对策建议

    Institute of Scientific and Technical Information of China (English)

    王明建; 周蓬; 孔鹏

    2012-01-01

    In the 21st century,the rapid development of economic globalization and global informatization made the competition among enterprises more and more intense and in increasing level.With the development of economic globalization,the informatization has become a must of the survival and development of enterprise.Informatization has become the determinants of survival and development,become an important part of business strategy,and been an important way to enhance the competitiveness of enterprises.The paper started from the significance of informatization of the enterprise,the development status and other aspects to analyze the bottlenecks in current informatization of small and medium enterprises and make recommendations and countermeasures.%21世纪全球信息化与经济全球化迅猛发展,竞争层次也越来越高,企业之间的竞争越来越激烈。企业信息化建设,随着经济全球化的发展,已经成为企业生存发展的必经之路。信息化建设已成为企业经营战略的重要内容,成为企业生存与发展的决定因素,是企业提升竞争力的重要途径。从中小企业发展现状及信息化的意义等方面入手,讨论目前中小企业信息化建设存在的瓶颈问题,并提出相关建议及解决对策。

  11. 科技期刊提升学术质量的若干瓶颈问题及其对策%Few Bottleneck Problems and Solutions in Promoting the Academic Quality of Scientific Journals

    Institute of Scientific and Technical Information of China (English)

    俞祚华

    2011-01-01

    学术质量是科技期刊的立身之本.但科技期刊提升学术质量目前存在着种种阻碍.提出了科技期刊特别是学术型期刊提升学术质量过程中存在的6大瓶颈问题,包括内容上的综合性直接制约影响因子、期刊编辑与科研缺乏融合而形成"源头受阻"、期刊人才队伍建设滞后、学术成果传播速度不快、运营体制机制及手段比较落后、期刊国际化程度低等,并在深入剖析的基础上提出了针对性的对策建议.%Academic quality is the foundation for scientific journals. However, there currently exist various obstacles to promote the academic quality. The paper identifies six major bottleneck problems in promoting academic quality of scientific journals, especially academic scientific journals. The six problems include: the comprehensiveness of the topics directly limits their impact factors; lack of integration among journal editing and scientific research blocks the source of good academic articles; human resource development in academic journals lag behind; research results spread at a low speed; the operation and distribution mechanisms of the journals are relatively outdated; the journals are not globalized enough. The study provides a thorough and insightful analysis, and proposes specific solutions and strategies targeting at the six major problems in promoting the quality of academic journals.

  12. 湖北省民族传统体育基地建设的瓶颈与机遇%About the bottleneck and chance of the national traditional sports base’s building in Hubei province

    Institute of Scientific and Technical Information of China (English)

    张辉

    2015-01-01

    Through the investigation on the current situation of national traditional sports base in Hebei Province , this article finds that the base’s bottlenecks are shortage of funds,insufficient facilities,draining and lacking of talents,and faulty base system etc.. Combined with the special nature of dependency relations between national traditional sports base and the school in Hubei province;and proposes to enrich and perfect the base system,to improve the distribution of bases,to promote the national fitness,government funding and their own income working along both lines, and the base construction and national traditional sports teaching organically combining;then it gives other suggestions for new opportunities of double development of the base and campus culture construction.%通过对湖北省民族传统体育基地的现状调研,发现存在经费紧张、场地设施不足、人才流失与匮乏、基地制度不完善等瓶颈限制。结合湖北省民族传统体育基地与学校依存关系的特殊性,提出丰富和完善基地制度、改善基地分布、促进全民健身、政府拨款与自身创收双管齐下、基地建设与民族传统体育教学有机融合等针对性建议,以期为基地建设与校园文化双重发展的新机遇建言献策。

  13. Operational Bottlenecks and Countermeasure Analysis with Regard to Post-Merger Overseas Resources of China’s Enterprises%中国境外资源并购后的运作瓶颈及对策分析

    Institute of Scientific and Technical Information of China (English)

    王溦溦; 李喜凤

    2013-01-01

    This paper analyses the operational bottlenecks with regard to post-merger overseas resources of China’s Enterprises, these include:there is conflict in the cross-cultural management;the follow-up funding have had difficulty raising capital;both decision-making and management process are not clear;and the qualified personnel in the transnational business operations is lack. This paper puts forward some initiatives aimed at the above problems. The main measures of focus include:making innovations of administrative method, and combining cultural integration with cultural transplantation;building multidimensional financing platform with innovation capital financing model;working out clear decision-making process and effectively improving the management level;making a new way of employing talents through both bringing in talents and cultivating more qualified faculties.%  中国企业境外资源并购后面临的运作瓶颈主要有:(1)跨文化管理方面的冲突;(2)在需要后续资金投入时,遭遇融资困难;(3)决策程序和管理流程不清晰;(4)国际经营管理人才缺乏。解决境外并购运作瓶颈的对策:(1)创新企业管理方式,文化整合和移植相结合;(2)创新资金融资模式,建立多维融资平台;(3)制定清晰的决策流程,有效提高管理水平;(4)创新用人方式,培养和引进相结合。

  14. Bottlenecks of blood processing in Uganda

    NARCIS (Netherlands)

    Kajja, I.; Kyeyune, D.; Bimenya, G. S.; Sibinga, C. T. S.

    2010-01-01

    Aim: To identify where and why delays occur in Uganda blood banks. Background: The timely provision and supply of safe and efficacious blood components to hospitals depends on sound systems in the processing blood banks. Poorly managed systems lead to apparent blood shortages in hospitals and increa

  15. Progress and bottleneck in induced pluripotency

    Directory of Open Access Journals (Sweden)

    Zhang Zhen-Ning

    2012-07-01

    Full Text Available Abstract With their capability to undergo unlimited self-renewal and to differentiate into all cell types in the body, induced pluripotent stem cells (iPSCs, reprogrammed from somatic cells of individual patients with defined factors, have unlimited potential in cell therapy and in modeling complex human diseases. Significant progress has been achieved to improve the safety of iPSCs and the reprogramming efficiency. To avoid the cancer risk and spontaneous reactivation of the reprogramming factors associated with the random integration of viral vectors into the genome, several approaches have been established to deliver the reprogramming factors into the somatic cells without inducing genetic modification. In addition, a panel of small molecule compounds, many of which targeting the epigenetic machinery, have been identified to increase the reprogramming efficiency. Despite these progresses, recent studies have identified genetic and epigenetic abnormalities of iPSCs as well as the immunogenicity of some cells derived from iPSCs. In addition, due to the oncogenic potential of the reprogramming factors and the reprogramming-induced DNA damage, the critical tumor suppressor pathways such as p53 and ARF are activated to act as the checkpoints that suppress induced pluripotency. The inactivation of these tumor suppression pathways even transiently during reprogramming processes could have significant adverse impact on the genome integrity. These safety concerns must be resolved to improve the feasibility of the clinic development of iPSCs into human cell therapy.

  16. A bottleneck capital model of development

    OpenAIRE

    Jordan Rappaport

    2002-01-01

    A convex marginal adjustment cost allows the neoclassical growth model to match observed transition paths for output growth, savings, investment, the real interest rate, and the shadow value of installed capital. Such an adjustment cost need apply only to one of two complementary capital inputs with minimal factor income share. The interaction of complementary capital inputs blurs the distinction between capital accumulation and productivity growth.

  17. Crossing the bottleneck of rain formation

    OpenAIRE

    Rohloff, Martin; Lapp, Tobias; Vollmer, Jürgen

    2014-01-01

    The demixing of a binary fluid mixture, under gravity, is a two stage process. Initially droplets, or in general aggregates, grow diffusively by collecting supersaturation from the bulk phase. Subsequently, when the droplets have grown to a size, where their Peclet number is of order unity, buoyancy substantially enhances droplet growth. The dynamics approaches a finite-time singularity where the droplets are removed from the system by precipitation. The two growth regimes are separated by a ...

  18. EU to tackle trucker bottlenecks / Todd Graham

    Index Scriptorium Estoniae

    Graham, Todd

    2006-01-01

    Läti peaminister Aigars Kalvitis ütles Euroopa Komisjonis, et veoautode järjekorra probleem piiril on ka Euroopa ühine mure. Ainult Venemaa tolli olukorras süüdistada ei saa. Tabel: Trucks on the border

  19. Analysis on Real-Time Bottleneck Factors Influencing Power System Recording System%电力录波系统实时性瓶颈影响因素分析

    Institute of Scientific and Technical Information of China (English)

    邢浩江; 张东来; 张斌; 王超; 李悦

    2011-01-01

    电力录波系统的性能受多因素制约,以致系统实时性较难提高,鉴于此,采用改进的基于链路层网络传输方法,通过应用层直接访问网络控制器,避免了系统中对数据帧的封装与解析的冗余操作,提高了系统实时性.通过对系统中各接口数据处理时间的精确测量,可知制约电力录波系统实时性的主要因素为处理器间总线访问速度、录波文件形成效率、故障文件存储与网络传输速度,且网络传输速度为影响系统实时性瓶颈因素.通过后置存储功能,调整并行总线访问模式,优化故障录波文件形成逻辑,以减小对实时性的影响.实际测试验证了系统功能的有效性与实时性.%The performance of power recording system is restricted by many factors so that it is difficult to improve the real-time performance of recording system. For this reason, to improve real-time performance of power recording system such measures as utilizing improved link-layer based network transmission technique and directly accessing network controller via application layer to avoid the redundant operation in data packaging and unpacking are proposed. By means of accurately measuring processing time of interface data within the recording system the main restrictive factors, including bus accessing speed among processors, forming efficiency of record files, storage of fault files and network transmission speed, are revealed, and the network transmission speed is the very bottleneck factor influencing the real-time performance of the recording system.Using the measures such as postposition of storage function,adjusting parallel bus access mode and optimizing forming logic of recorded fault file, the influence of these factors on real-time performance of the recording system is mitigated. Actual testing results verify the effectiveness and real-time performance of the improved recording systen.

  20. Bottleneck, optimum strategy and relevant policy evolution of Three Networks Convergence%三网融合的制约、较优策略与关联政策演进

    Institute of Scientific and Technical Information of China (English)

    岳宇君; 葛伟

    2015-01-01

    Three Networks Convergence entered a substantive stage in 2010 after more than a decade of plan-ning. Seen from the pilot and promotion work of more than five years, there remain administrative intervention, business bidirectional access barriers, discriminatory competition and difficulty in sharing which affect the promo-tion of the convergence. The traditional pattern of separate supervision leads to“multi-management”,“overlapping regulation” and regulatory obstacles that constitute the bottleneck for the convergence. It is necessary to follow the technical and economic characteristics and political organization, striving for the synchronous occurrence of promo-ting three networks convergence and changing regulatory policy. The strategic goals of three networks convergence could be achieved by examining experimental work with dynamic and evolutionary thinking paradigm, focusing on rationalizing different stakeholders’ interest, and exploring the incentives stimulating their concerted action, while at the same time strengthening “top designing”.%酝酿十多年的三网融合在2010年进入实质阶段,从五年多的试点及推广工作来看,存在行政干预、业务双向准入壁垒、歧视性竞争和共建共享难以实现等影响融合推进的因素。分业监管的传统格局导致“多头管理”“规制重叠”,规制障碍成为三网融合的瓶颈。遵循技术经济特征和政治组织架构,力争“三网融合”的推进和规制政策同时转变;以动态、演化思维范式来审视试点工作,注重理顺各参与主体之间的利益关系,探索刺激各主体协同行动的激励机制,同时加强“顶层设计”,有助于三网融合战略目标的实现。

  1. Optimization of Energy Storage System Capacity for Relaxing Peak Load Regulation Bottlenecks%用于松弛调峰瓶颈的储能系统容量配置方法

    Institute of Scientific and Technical Information of China (English)

    严干贵; 冯晓东; 李军徽; 穆钢; 谢国强; 董效辰; 王芝茗; 杨凯

    2012-01-01

    利用大规模电池储能系统对电网负荷“削峰填谷”,减少日负荷波动幅度,可以缓解发电机组对负荷追踪调控负担,使电网具备更多向下调节容量来接纳风电.基于给定的负荷特性,分析储能系统配置容量与其改善负荷波动水平之间的关系,以储能系统投资成本、经济效益为约束,以综合效益最大为目标,提出一种用于松弛调峰瓶颈的大规模储能系统容量优化配置方法.针对2010年某省电网接纳风电受限现状,利用该方法对其进行改善,分析了储能系统运行年限、投资成本对其容量配置的影响,算例结果验证了所提出方法的可行性.%Using large-scale battery energy storage systems for load shifting and peak smoothing can decrease the fluctuation of daily load and reduce load tracking regulation burden of generator units, and enlarge down-regulate space to accommodate wind power. Based on a given load characteristics, the relationship between the energy storage system allocation capacity and improvement of load fluctuations was analyzed. By making energy storage system's investment costs and economic benefits as constraints, and by maximizing the comprehensive benefits as the object, an optimal capacity-allocation method was proposed for large-scale energy storage systems to relax peak-regulation bottleneck. For the limitation of wind power accommodation of a province in China in 2010, the method was applied to improve the situation and the impact of the life cycle and investment cost of the energy storage system on its capacity configuration. Case study results verified the feasibility of the proposed method.

  2. Bottleneck breakthrough of start-ups' growth : the mediating effect of government-enterprise interaction and the moderating effect of policy perception%创业企业成长瓶颈突破——政企互动的中介作用与政策感知的

    Institute of Scientific and Technical Information of China (English)

    彭华涛

    2013-01-01

    以政府部门推动创业企业成长的政策导向为自变量,以创业企业成长过程中的政企互动为中介变量,以创业企业的政策感知为调节变量,以创业企业成长的瓶颈突破为因变量,构建了相应的理论框架;借助于探索性因子分析、验证性因子分析、中介效应和调节效应的回归模型,得出:政策导向对于创业企业成长的瓶颈突破具有正向影响;政策导向通过政企活动部分中介作用于创业企业成长的瓶颈突破;政策感知对于政企互动与创业企业成长的瓶颈突破之间的关系具有显著的调节作用.%Taking the policy orientation of government to promote start-ups' growth as the independent variable,the government-enterprise interaction during start-ups' growth as the mediator variable,the policy perception of start-ups as the moderator variable,the bottleneck breakthrough of start-ups' existence and development,this paper built up corresponding theoretical framework.By means of EFA,CFA,the regression models of mediating effect and moderating effect,this paper got the conclusions that policy orientation wos positively relevant with the bottleneck breakthrough during start-ups' growth.Policy orientation positively influence the bottleneck breakthrough during start-ups' growth by means of the mediating effect of government-enterprise interaction.Policy perception has significantly moderating effect on the relationship between government-enterprise interaction and bottleneck breakthrough during start-ups' growth.

  3. 新媒体下高校学生网站建设的瓶颈与思考--以浙江大学求是潮为例%On the Bottlenecks and Way-out of University Students Website Construction,under New Media Background---Taking Qiushi Chao Website of Zhej iang University as an Example

    Institute of Scientific and Technical Information of China (English)

    周伟辉

    2015-01-01

    With the rapid development of new media,university students website construction turns to face new challenges.The present study,taking Qiushi Chao Website of Zhejiang University as an example,summarizes the bottlenecks in university students website construction,analyzes the reasons why the number of users and visitors is dropping off,thus puts forward some suggestions for the transformation and upgrading of university students website construction.%新媒体的迅速发展,冲击着高校学生网站的建设。本文以浙江大学求是潮网站为例,从网站建设过程中遭受的瓶颈出发,浅析用户流失的原因,并提出高校学生网站转型升级的途径与未来。

  4. 成人高等教育学生就业瓶颈探析——基于公共政策执行视角%Analysis of Employment Bottleneck for Students of Adult Higher Education ——Based on Perspective of Pub|ie Policy Implementation

    Institute of Scientific and Technical Information of China (English)

    韦仕祺

    2012-01-01

    Currently the employment for graduate students of aduh higher education is far from optimistic and the designing bottleneck in the system leads to one of the main difficulties in the employment, the reason of which is due to the deviation existing in the design of the system in the public policy and also the deviation can be caused by people who carry out the policy, leading to double psychological worries about learning at school and employment after graduation for adult students. The article tries to analyze the reason of employment bottleneck for students of adult education from the perspective of public policy and on this basis to explore some countermeasures and recommendations on fairness in employment supported by the policy.%当前成人高等教育毕业学生的就业状况不容乐观,究其原因是公共政策存在着制度设计上的偏差,同时人为地制造政策执行的偏差也引起了成人教育学生在校学习与毕业就业压力双重心理的担忧。本文从公共政策执行视角分析成人教育学生就业瓶颈的症结所在,并在此基础上提出成人教育学生获得政策公平就业对待的对策建议。

  5. Research and Development Status and the Bottleneck Breakthrough Ideas of 3D Printing Technology and Orthopaedic Implants%3D 打印技术与骨科植入物研发现状及其瓶颈突破思路

    Institute of Scientific and Technical Information of China (English)

    汤啸天; 王燎

    2015-01-01

    Implants are the core elements of skeletal muscle treatment system with enormous social and eco-nomic effects. The localized and individualized demand for orthopaedic implants forced its research and develop-ment work. In the research field of orthopedic implants, the way for clinical application of 3D printing technology has been paved, and the research and development of orthopaedic implants based on 3D printing technology need legal guarantee. Individualized production is the advantage of 3D printing and the bottleneck of legal restrictions as well, so reform and innovation are needed to break through its application bottleneck. And the following are the solutions to the problems in individualized production of medical equipments by 3D printing technology: 1. Submit to the National Food and Drug Administration for approval of setting up 3D printing pilot clinical application in Shanghai; 2. Suggest signing Consensus Memorandum of Cooperation to prevent common risks; 3. Suggest devel-oping special accident insurance to promote science and technology innovation.%植入物是骨肌系统治疗的核心要素,其社会及经济影响巨大。骨科植入物国产化及个体化需求倒逼研发工作;在骨科植入物研究领域中,3D 打印技术的临床应用已经铺平了道路,基于3D 打印技术的骨科植入物研发亟待法治化保障。个体化生产是3D 打印技术的优势也是法律限制的瓶颈,需改革创新方能突破3D 打印技术医疗应用瓶颈。破解3D 打印技术个体化生产医疗器械难题的思路:第一,报请国家食药监局批准在上海建立3D 打印技术临床应用试点;第二,建议签署《合作共识备忘录》共同防范风险;第三,建议开发特殊意外保险推进科学技术创新。

  6. 3D 打印技术与骨科植入物研发现状及其瓶颈突破思路%Research and Development Status and the Bottleneck Breakthrough Ideas of 3D Printing Technology and Orthopaedic Implants

    Institute of Scientific and Technical Information of China (English)

    汤啸天; 王燎

    2015-01-01

    植入物是骨肌系统治疗的核心要素,其社会及经济影响巨大。骨科植入物国产化及个体化需求倒逼研发工作;在骨科植入物研究领域中,3D 打印技术的临床应用已经铺平了道路,基于3D 打印技术的骨科植入物研发亟待法治化保障。个体化生产是3D 打印技术的优势也是法律限制的瓶颈,需改革创新方能突破3D 打印技术医疗应用瓶颈。破解3D 打印技术个体化生产医疗器械难题的思路:第一,报请国家食药监局批准在上海建立3D 打印技术临床应用试点;第二,建议签署《合作共识备忘录》共同防范风险;第三,建议开发特殊意外保险推进科学技术创新。%Implants are the core elements of skeletal muscle treatment system with enormous social and eco-nomic effects. The localized and individualized demand for orthopaedic implants forced its research and develop-ment work. In the research field of orthopedic implants, the way for clinical application of 3D printing technology has been paved, and the research and development of orthopaedic implants based on 3D printing technology need legal guarantee. Individualized production is the advantage of 3D printing and the bottleneck of legal restrictions as well, so reform and innovation are needed to break through its application bottleneck. And the following are the solutions to the problems in individualized production of medical equipments by 3D printing technology: 1. Submit to the National Food and Drug Administration for approval of setting up 3D printing pilot clinical application in Shanghai; 2. Suggest signing Consensus Memorandum of Cooperation to prevent common risks; 3. Suggest devel-oping special accident insurance to promote science and technology innovation.

  7. 智能电网——大规模风、光电并网瓶颈问题的解决方案%The smart grid─ the best of all scheme to solve the bottleneck problems of wind power and photoelectric power generation connected with power network on a large scale

    Institute of Scientific and Technical Information of China (English)

    徐娟; 孙大伟

    2012-01-01

    Aiming at the problems of the security and stability of power network caused by load undulation or power quality not good when wind power and photoelectric power generation connected with power network on a large scale.Through analyzing and comparing to find out: the smart grid with powerful capacity,facility and compatibility,con fit multiform power supply to connect with and contain it.The result of research shows that developing the smart grid maybe is the best of all scheme to solve the bottleneck problems of wind power and photoelectric power generation connected with power network on a large scale.%针对大规模风、光发电集中接入电网后产生的负荷波动性及电能质量较差,给电网带来的安全性和稳定性问题,通过分析对比发现,智能电网具有很好的智能性、灵活性和兼容性,不但成功地解决了上述问题还可以适应多种形式的电源接入并能将其成功消纳。研究表明:发展智能电网是解决大规模风、光发电并网瓶颈问题的最佳方案。

  8. Expansion of biowaste collection as a means of resolving capacity bottlenecks in residual waste treatment - new incentives from the Landfill Ordinance and the Renewable Energy Law; Ausweitung der Bioabfallerfassung als Massnahme zur Loesung von Kapazitaetsengpaessen bei der Restabfallbehandlung - AbfAblV und EEG schaffen neue Anreize

    Energy Technology Data Exchange (ETDEWEB)

    Kern, M. [Witzenhausen-Institut fuer Abfall, Unwelt und Energie GmbH (Germany)

    2006-07-01

    One year after the enactment of the Landfill Ordinance the German Federal Environment Ministry sees no alleviation of Germany's shortage of waste disposal capacities. According to the Laender Working Group on Wastes (LAGA) some 1.2 mil. Mg of high-caloric and untreated wastes distributed over more than 70 interim stores currently await final disposal (EUWID, 2006). The Federal Ministry for Environment, Nature Conservation and Reactor Safety (BMU) has stated that in mid-2006 ca. 16.3 mil. Mg of waste incineration capacity and ca. 5.5 mil. Mg of mechanical biological waste treatment capacity were available. The forecast 2.3 mil. Mg of mono-/co-combustion capacity have not been reached so far. At the same time Germany has substantial unused capacity for biological waste treatment. This brings to one's mind the obvious idea of expanding the collection of biowastes, thus also easing the bottleneck in residual waste disposal. This notion gains all the more significance as many municipalities run their biowaste collection system suboptimally or have none in place at all. The present article documents arisings and available waste treatment capacities for biowaste and green waste and points out new utilisation options, particularly with a mind to the German Renewable Energy Law.

  9. Bottlenecks to Clinical Translation of Direct Brain-Computer Interfaces

    Directory of Open Access Journals (Sweden)

    Mijail Demian Serruya

    2014-12-01

    Full Text Available Despite several decades of research into novel brain-implantable devices to treat a range of diseases, only two- cochlear implants for sensorineural hearing loss and deep brain stimulation for movement disorders- have yielded any appreciable clinical benefit. Obstacles to translation include technical factors (e.g., signal loss due to gliosis or micromotion, lack of awareness of current clinical options for patients that the new therapy must outperform, traversing between federal and corporate funding needed to support clinical trials, and insufficient management expertise. This commentary reviews these obstacles preventing the translation of promising new neurotechnologies into clinical application and suggests some principles that interdisciplinary teams in academia and industry could adopt to enhance their chances of success.

  10. Communities and bottlenecks: trees and treelike networks have high modularity.

    Science.gov (United States)

    Bagrow, James P

    2012-06-01

    Much effort has gone into understanding the modular nature of complex networks. Communities, also known as clusters or modules, are typically considered to be densely interconnected groups of nodes that are only sparsely connected to other groups in the network. Discovering high quality communities is a difficult and important problem in a number of areas. The most popular approach is the objective function known as modularity, used both to discover communities and to measure their strength. To understand the modular structure of networks it is then crucial to know how such functions evaluate different topologies, what features they account for, and what implicit assumptions they may make. We show that trees and treelike networks can have unexpectedly and often arbitrarily high values of modularity. This is surprising since trees are maximally sparse connected graphs and are not typically considered to possess modular structure, yet the nonlocal null model used by modularity assigns low probabilities, and thus high significance, to the densities of these sparse tree communities. We further study the practical performance of popular methods on model trees and on a genealogical data set and find that the discovered communities also have very high modularity, often approaching its maximum value. Statistical tests reveal the communities in trees to be significant, in contrast with known results for partitions of sparse, random graphs. PMID:23005173

  11. Search engines, the new bottleneck for content access

    NARCIS (Netherlands)

    N. van Eijk

    2009-01-01

    The core function of a search engine is to make content and sources of information easily accessible (although the search results themselves may actually include parts of the underlying information). In an environment with unlimited amounts of information available on open platforms such as the inte

  12. Larynx during exercise: the unexplored bottleneck of the airways

    OpenAIRE

    2014-01-01

    Exercise-induced shortness of breath is not uncommon in otherwise healthy young people. Based on the presenting symptoms alone, it is challenging to distinguish exercise-induced asthma (EIA) from exercise-induced obstruction of central airways, sometimes leading to diagnostic errors and inadequate treatment. Central airway obstruction usually presents with exercise-induced inspiratory symptoms (EIIS) during ongoing exercise. EIIS tends to peak towards the end of an exercise session or immedia...

  13. The Problem State: A Cognitive Bottleneck in Multitasking

    Science.gov (United States)

    Borst, Jelmer P.; Taatgen, Niels A.; van Rijn, Hedderik

    2010-01-01

    The main challenge for theories of multitasking is to predict when and how tasks interfere. Here, we focus on interference related to the problem state, a directly accessible intermediate representation of the current state of a task. On the basis of Salvucci and Taatgen's (2008) threaded cognition theory, we predict interference if 2 or more…

  14. The Problem State : A Cognitive Bottleneck in Multitasking

    NARCIS (Netherlands)

    Borst, Jelmer P.; Taatgen, Niels A.; van Rijn, Hedderik

    2010-01-01

    The main challenge for theories of multitasking is to predict when and how tasks interfere. He re, we focus on interference related to the problem state. a directly accessible intermediate representation of the current state of a task. On the basis of Salvucci and Taatgen's (2008) threaded cognition

  15. Bacteria Delay the Jamming of Particles at Microchannel Bottlenecks.

    Science.gov (United States)

    Sendekie, Zenamarkos Bantie; Gaveau, Arthur; Lammertink, Rob G H; Bacchin, Patrice

    2016-01-01

    Clogging of channels by complex systems such as mixtures of colloidal and biological particles is commonly encountered in different applications. In this work, we analyze and compare the clogging mechanisms and dynamics by pure and mixture suspensions of polystyrene latex particles and Escherichia coli by coupling fluorescent microscopic observation and dynamic permeability measurements in microfluidic filters. Pure particles filtration leads to arches and deposit formation in the upstream side of the microfilter while pure bacteria form streamers in the downstream zone. When mixing particle and bacteria, an unexpected phenomenon occurs: the clogging dynamics is significantly delayed. This phenomenon is related to apparent "slippery" interactions between the particles and the bacteria. These interactions limit the arches formation at the channels entrances and favour the formation of dendritic structures on the pillars between the channels. When these dendrites are eroded by the flow, fragments of the deposit are dragged towards the channels entrances. However, these bacteria/particles clusters being lubricated by the slippery interactions are deformed and stretched by the shear thus facilitating their passage through the microchannels. PMID:27510611

  16. Caching Eliminates the Wireless Bottleneck in Video Aware Wireless Networks

    Directory of Open Access Journals (Sweden)

    Andreas F. Molisch

    2014-01-01

    Full Text Available Wireless video is the main driver for rapid growth in cellular data traffic. Traditional methods for network capacity increase are very costly and do not exploit the unique features of video, especially asynchronous content reuse. In this paper we give an overview of our work that proposed and detailed a new transmission paradigm exploiting content reuse and the widespread availability of low-cost storage. Our network structure uses caching in helper stations (femtocaching and/or devices, combined with highly spectrally efficient short-range communications to deliver video files. For femtocaching, we develop optimum storage schemes and dynamic streaming policies that optimize video quality. For caching on devices, combined with device-to-device (D2D communications, we show that communications within clusters of mobile stations should be used; the cluster size can be adjusted to optimize the tradeoff between frequency reuse and the probability that a device finds a desired file cached by another device in the same cluster. In many situations the network throughput increases linearly with the number of users, and the tradeoff between throughput and outage is better than in traditional base-station centric systems. Simulation results with realistic numbers of users and channel conditions show that network throughput can be increased by two orders of magnitude compared to conventional schemes.

  17. Inverse bottleneck in Eu2+-Mn2+ energy transfer

    International Nuclear Information System (INIS)

    The energy transfer (ET) between Eu2+ and Mn2+ in Ca5(PO4)3Cl has been investigated. At low intensities under 405 nm excitation, time-resolved experiments provide microscopic parameters for the energy transfer between adjacent Eu2+ and Mn2+ ions. At high intensities, we observe a non-linear component in the energy transfer process due to ground state depletion of the Mn2+ ions, leading not to a reduction, but to an increase in the energy transfer rate between Eu2+ and Mn2+ ions and also energy transfer between excited Mn2+ ions. This results in a sub-linear response of both Eu2+ and Mn2+ luminescence as a function of intensity. Our observations are quantitatively described by a model using energy transfer to Mn2+ ions in both the ground and the excited state.

  18. [Dealing with bottlenecks in health care: legal implications].

    Science.gov (United States)

    Katzenmeier, Christian

    2010-01-01

    Scarcity in the German health care system leads to an implicit allocation of means and also implies a risk of liability for physicians. Prioritisation can contribute to the solution of these problems and ascertain an equitable allocation of scarce resources. However, the criteria that will be applied to establish a ranking order will have to be thoroughly considered, particularly in light of the constitutional law, and there is still a multitude of unresolved questions seeking an answer. This requires an open political discourse about society and health care. PMID:20870484

  19. A CAPACITY EXPANSION PROBLEM WITHBUDGET CONSTRAINT AND BOTTLENECK LIMITATION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper considers a capacity expansion problem with budget constraint.Suppose each edge in the network has two attributes: capacity and the degree of difficulty.The difficulty degree of a tree T is the maximum degree of difficulty of all edges in the tree and the cost for coping with the difficulty in a tree is a nondecreasing function about the difficulty degree of the tree. The authors need to increase capacities of some edges so that there is a spanning tree whose capacity can be increased to the maximum extent.meanwhile the total cost for increasing capacity as well as overcoming the difficulty in the spanning tree does not exceed a given budget D*. Suppose the cost for increasing capacity on each edge is a linear function about the increment of capacity, they transform this problem into solving some hybrid parametric spanning tree problems[1] and propose a strongly polynomial algorithm.

  20. Paradigm shift in transport legislation or rather at the 'bottleneck'

    International Nuclear Information System (INIS)

    In the year just started significant decisions with considerable consequences by the Federal Constitutional Court and the Federal Administrative Court in the field of nuclear law are expected. Especially the decision with regards to 'nuclear phase-out' within the 13th amendment of the Atomic Energy Act is being eagerly expected, as with its far-reaching consequences also fundamental constitutional questions need to be answered. The Federal Administrative Court will need to decide on the question, whether she admits the appeal against the Brunsbuettel decision by the Higher Administrative Court Schleswig-Holstein (HAC), which from the view of claimant shifted the fundamental basis of demarcation of responsibilities between the executive and judiciary power. In comparison to these fundamental decisions the awaited decision by the HAC on nuclear transport legislation seems of subordinate importance, although she will proceed with a paradigm shift in the legal area. The decision deals with the question as to whether and when a right of action from a third party within the nuclear transport legislation can be accepted or more precisely under which preconditions a third party has clear standing against a nuclear transport authorisation. As the site selection law (issued on 23 July 2013 BGBI I p. 2552) excludes the recirculation of vitrified waste block canisters from reprocessing spent fuel elements to the transport cask storage facility Gorleben, the decision by the HAC Lueneburg for this site will only be relevant for present unpredictable transportations from the transport cask storage facility Gorleben to a final repository. If necessary interest to seek a declaratory judgment for declaratory action, in concreto danger of recurrence will be approved, is another matter.

  1. Invited review: Clogging of granular materials in bottlenecks

    Directory of Open Access Journals (Sweden)

    Iker Zuriguel

    2014-12-01

    Full Text Available During the past decades, notable improvements have been achieved in the understanding of static and dynamic properties of granular materials, giving rise to appealing new concepts like jamming, force chains, non-local rheology or the inertial number. The 'saltcellar' can be seen as a canonical example of the characteristic features displayed by granular materials: an apparently smooth flow is interrupted by the formation of a mesoscopic structure (arch above the outlet that causes a quick dissipation of all the kinetic energy within the system. In this manuscript, I will give an overview of this field paying special attention to the features of statistical distributions appearing in the clogging and unclogging processes. These distributions are essential to understand the problem and allow subsequent study of topics such as the influence of particle shape, the structure of the clogging arches and the possible existence of a critical outlet size above which the outpouring will never stop. I shall finally offer some hints about general ideas that can be explored in the next few years.

  2. Spurious Products: A Bottleneck in Growth and Development

    OpenAIRE

    Nanda, Ch Siddharth; Kantha, Dr. Ranjan Kumar

    2015-01-01

    Creativity and innovation are proven factors for economic growth and competitive advantage. In this cut throat competition being a first mover backed with innovative offerings will for sure create a blue ocean. However as the competition gets fierce it becomes imperative for organizations to not only be creative and innovative but also tune its offerings according to consumer requirements. As the consumer is emerging as the ultimate decider for the success of a product, creating and susta...

  3. Squeezing bottlenecks: exploring the limits of autoencoder semantic representation capabilities

    OpenAIRE

    Gupta, Parth; Banchs, Rafael E.; Rosso, Paolo

    2014-01-01

    We present a comprehensive study on the use of autoencoders for modelling text data, in which (differently from previous studies) we focus our attention on the following issues: i) we explore the suitability of two different models bDA and rsDA for constructing deep autoencoders for text data at the sentence level; ii) we propose and evaluate two novel metrics for better assessing the text-reconstruction capabilities of autoencoders; and iii) we propose an automatic method to find the critica...

  4. The planning flexibility bottleneck in food processing industries

    NARCIS (Netherlands)

    van Wezel, W.M.C.; van Donk, D.P.; Gaalman, G.J.C.

    2006-01-01

    Production planners in food processing industries must continuously balance efficient production with flexible performance. On the basis of case studies, we state that flexibility is not only restrained by hard-wired production process characteristics, but also by organizational procedures in the pl

  5. Personalized Medicine’s Bottleneck: Diagnostic Test Evidence and Reimbursement

    Directory of Open Access Journals (Sweden)

    Joshua P. Cohen

    2014-04-01

    Full Text Available Background: Personalized medicine is gradually emerging as a transformative field. Thus far, seven co-developed drug-diagnostic combinations have been approved and several dozen post-hoc drug-diagnostic combinations (diagnostic approved after the drug. However, barriers remain, particularly with respect to reimbursement. Purpose, methods: This study analyzes barriers facing uptake of drug-diagnostic combinations. We examine Medicare reimbursement in the U.S. of 10 drug-diagnostic combinations on the basis of a formulary review and a survey. Findings: We found that payers reimburse all 10 drugs, but with variable and relatively high patient co-insurance, as well as imposition of formulary restrictions. Payer reimbursement of companion diagnostics is limited and highly variable. In addition, we found that the body of evidence on the clinical- and cost-effectiveness of therapeutics is thin and even less robust for diagnostics. Conclusions, discussion: The high cost of personalized therapeutics and dearth of evidence concerning the comparative clinical effectiveness of drug-diagnostic combinations appear to contribute to high patient cost sharing, imposition of formulary restrictions, and limited and variable reimbursement of companion diagnostics. Our findings point to the need to increase the evidence base supportive of establishing linkage between diagnostic testing and positive health outcomes.

  6. Fungal specificity bottlenecks during orchid germination and development.

    Science.gov (United States)

    Bidartondo, Martin I; Read, David J

    2008-08-01

    Fungus-subsidized growth through the seedling stage is the most critical feature of the life history for the thousands of mycorrhizal plant species that propagate by means of 'dust seeds.' We investigated the extent of specificity towards fungi shown by orchids in the genera Cephalanthera and Epipactis at three stages of their life cycle: (i) initiation of germination, (ii) during seedling development, and (iii) in the mature photosynthetic plant. It is known that in the mature phase, plants of these genera can be mycorrhizal with a number of fungi that are simultaneously ectomycorrhizal with the roots of neighbouring forest trees. The extent to which earlier developmental stages use the same or a distinctive suite of fungi was unclear. To address this question, a total of 1500 packets containing orchid seeds were buried for up to 3 years in diverse European forest sites which either supported or lacked populations of helleborine orchids. After harvest, the fungi associated with the three developmental stages, and with tree roots, were identified via cultivation-independent molecular methods. While our results show that most fungal symbionts are ectomycorrhizal, differences were observed between orchids in the representation of fungi at the three life stages. In Cephalanthera damasonium and C. longifolia, the fungi detected in seedlings were only a subset of the wider range seen in germinating seeds and mature plants. In Epipactis atrorubens, the fungi detected were similar at all three life stages, but different fungal lineages produced a difference in seedling germination performance. Our results demonstrate that there can be a narrow checkpoint for mycorrhizal range during seedling growth relative to the more promiscuous germination and mature stages of these plants' life cycle.

  7. Identification of bottlenecks for P450 biotransformation processes

    DEFF Research Database (Denmark)

    Andersson, Marie Therese; Törnvall, Ulrika; Tufvesson, Pär;

    Cytochrome P450 monooxygenases (P450 or CYP) is a group of heme-containing enzymes hydroxylating non-activated hydrocarbons in a stereospecific manner, something that is hard to achieve via classical chemistry. The importance of these reactions can be stressed by the hydroxylation of steroids, bu...

  8. Is follow-up capacity the current NHS bottleneck?

    Science.gov (United States)

    Allder, Steven; Walley, Paul; Silvester, Kate

    2011-02-01

    Capacity and demand theory suggests that the presence of a queue is not necessarily an indication of a shortage of capacity in a system. It is much more likely that either there is a demand and capacity variation that creates queues or there is a delay designed into the system. A shortage of capacity is only really indicated where a backlog is not stable and continues to grow. In this article, data are taken from one NHS trust that provides evidence for a continually growing backlog for follow-up outpatient services. It is believed that these data are representative of most locations within the NHS in England and therefore suggest an immediate shortage in effective follow-up capacity. To avoid compromise to patient care, the problem will have to be addressed before the situation becomes unmanageable. The paper highlights options to reduce or deflect demand or to increase effective capacity. PMID:21404781

  9. Bottlenecks for metabolic engineering of isoflavone glycoconjugates in Arabidopsis

    OpenAIRE

    Liu, Chang-Jun; Blount, Jack W.; Steele, Christopher L.; Dixon, Richard A.

    2002-01-01

    In view of their perceived chemopreventive activities against hormone-dependent cancers, cardiovascular disease, and postmenopausal ailments, there is considerable interest in engineering plants to contain isoflavone phytoestrogens. However, attempts to date have only resulted in low levels of isoflavone accumulation in non-legumes. Introducing soybean isoflavone synthase (IFS) into Arabidopsis thaliana leads to accumulation of low levels of genistein glycosides. Leaves of wild-type A. thalia...

  10. Human-Machine CRFs for Identifying Bottlenecks in Scene Understanding.

    Science.gov (United States)

    Mottaghi, Roozbeh; Fidler, Sanja; Yuille, Alan; Urtasun, Raquel; Parikh, Devi

    2016-01-01

    Recent trends in image understanding have pushed for scene understanding models that jointly reason about various tasks such as object detection, scene recognition, shape analysis, contextual reasoning, and local appearance based classifiers. In this work, we are interested in understanding the roles of these different tasks in improved scene understanding, in particular semantic segmentation, object detection and scene recognition. Towards this goal, we "plug-in" human subjects for each of the various components in a conditional random field model. Comparisons among various hybrid human-machine CRFs give us indications of how much "head room" there is to improve scene understanding by focusing research efforts on various individual tasks. PMID:26656579

  11. Intelligent Automated Diagnosis of Client Device Bottlenecks in Private Clouds

    CERN Document Server

    Widanapathirana, C; Sekercioglu, Y A; Ivanovich, M; Fitzpatrick, P; 10.1109/UCC.2011.42

    2012-01-01

    We present an automated solution for rapid diagnosis of client device problems in private cloud environments: the Intelligent Automated Client Diagnostic (IACD) system. Clients are diagnosed with the aid of Transmission Control Protocol (TCP) packet traces, by (i) observation of anomalous artifacts occurring as a result of each fault and (ii) subsequent use of the inference capabilities of soft-margin Support Vector Machine (SVM) classifiers. The IACD system features a modular design and is extendible to new faults, with detection capability unaffected by the TCP variant used at the client. Experimental evaluation of the IACD system in a controlled environment demonstrated an overall diagnostic accuracy of 98%.

  12. The"bottlenecks"and Solutions of Enterprise Skilled Personnel---Based on the Survey of 363 enterprises in Chongqing%企业技能人才队伍“瓶颈”制约及解决对策--基于重庆市363家企业的调查

    Institute of Scientific and Technical Information of China (English)

    李志; 邱萍; 蒋雨珈

    2015-01-01

    采用文献分析、问卷调查以及访谈法对重庆市363家不同性质企业的技能人才队伍状况进行了实证调查。研究发现,企业技能人才队伍存在以下“瓶颈”:多数企业技能人才数量短缺,素质不高;企业重视技能人才开发,但培训效果不理想;企业技能人才稳定性差,新员工招聘困难;企业缺乏系统的非物质激励体系,技能人才发展缺乏内在动力;与国有企业相比,民营企业的技能人才队伍存在明显劣势。在此基础上,结合国内外其它地区技能人才队伍建设先进经验,提出了加强企业技能人才队伍建设的对策建议。%Skilled personnel have an important significance for the long‐term development of enterprises .The paper con‐ducts an empirical investigation on the qualified personnel in 363 companies of Chong Qing through the literature analysis , questionnaires and interviews .It was found that there are some following "bottlenecks" in the corporate skilled team building :(1) Most companies do not have the high quality and insufficient number of skilled personnel ;(2) Enterprises attach importance to the skills training ,but the effect is not ideal ;(3) The skilled personnel in the Enterprise are poor sta‐bility and the recruitment of the new staff is very difficult ;(4) Enterprises lack a systematic incentive system to match the needs of the skilled personnel ;(5) Compared with the state‐owned enterprises ,the skilled personnel of private enterprises has an obvious disadvantage .On the basis of above mentioned ,it proposes the countermeasures to strengthen the entre‐preneurial skills of qualified personnel combined with the skilled team building in advanced experience of other regions at home and abroad .

  13. 影响高校思想政治理论课教学效果的瓶颈因素分析%Factors Attributing to the Bottleneck of the Teaching Effect of Courses about Ideological and Political Theory in Colleges and Universities

    Institute of Scientific and Technical Information of China (English)

    李光莉

    2012-01-01

    通过问卷调查发现高校思政课教学效果还有待改进,这与大学生对思政课教学内容的心理需要程度不很高有重要关系。从心理学角度分析,大学生对思政课教学内容的心理需要程度是影响其学习效果的重要制约因素,并据此认为,影响高校思政课教学效果的瓶颈是大学生的学习动机。为此,增强思政课教学效果,应注意提高大学生对思政课教学内容的心理需要程度,激发其学习动机,把思政课的"灌输"教学内容和学生心理"需要"内容结合起来,想方设法把"灌输内容"变为学生"需要内容"。%Through a questionnaire survey,we found that there is still some room for the improvement of the effect of ideological and political theory teaching,and this is involved with the lower extent of the psychological needs of college students for the teaching content.From a psychological point of view,the psychological needs of college students for the teaching content of the ideological and political theory affect their learning.As a result,it is quite obvious that the bottleneck impacting the teaching lies in students′ learning motivation.Enhancing the effect of ideological and political theory teaching should be guided by in ways:following raising students’ learning psychology,stimulating their learning motivation;unifying them by turning "content-instilling" to "content-seeking".

  14. 社会文化史研究的瓶颈与未来走向--读梁景和等著《现代中国社会文化嬗变研究(1919-1949)》札记%The Bottleneck Problems and the Future Research Direction of Socio-cultural History:the Review of Liang Jinghe et al .'s Evolution Study o f Modern Chinese Society and Culture(1919-1949)

    Institute of Scientific and Technical Information of China (English)

    李俊领

    2015-01-01

    From the empirical research to theoretic exploration ,the book ,Evolution Study of Modern Chinese Society and Culture(1919 -1949)‐on the Focus of Marriage · Family · Woman · Marital Sex and Entertainment w ritten by Liang Jinghe et al ,not only embodies the new advancements in the modern socio‐cultural history research in China ,but also reflects the"bottleneck "problems in this field .The main predicaments in empirical research are as follow s :first ,it is lack of chic stories;second ,it is still influenced by the research paradigms of modernization and revolution instead of socio‐cultural ideology ;third ,the aca‐demic review should be deepened .As to the theoretical exploration ,it is prospective and instructive to break through the current "bottleneck"and extends the further research directions to the historical interpretation system of making the"daily life"as the characteristics in the study of socio‐cultural history .%梁景和等著《现代中国社会文化嬗变研究(1919—1949)———以婚姻·家庭·妇女·性伦·娱乐为中心》一书,从实证研究到理论探索,既体现了中国近代社会文化史研究的新进展,也反映了该领域研究遭遇的瓶颈问题。其实证研究部分的困境主要表现为以下几点:一是缺少别致的好故事;二是在范式上缺少“社会文化史”研究的意识,仍未自觉走出现代化与革命史范式的影响;三是学术史回顾的功课有待深入。该书的理论探索富有前瞻性,对于社会文化史研究突破当前的瓶颈确有启发意义。沿着该书的理论思考方向,将“日常生活”建构为社会文化史特色的历史诠释体系,或为该领域研究未来的可能走向。

  15. Are communities just bottlenecks? Trees and treelike networks have high modularity

    CERN Document Server

    Bagrow, James P

    2012-01-01

    Much effort has gone into understanding the modular nature of complex networks. Communities, also known as clusters or modules, are densely interconnected groups of nodes that are only sparsely connected to other groups in the network. Discovering high quality communities is a difficult and important problem in a number of areas. The most popular approach is the objective function known as Modularity, used to both discover communities and measure their strength. To understand the modular structure of networks it is then crucial to know how such functions evaluate different topologies, what features they account for and what implicit assumptions they may make. We show that trees and treelike networks can have unexpectedly and often arbitrarily high values of modularity. This is surprising since trees are maximally sparse connected graphs and are not typically considered to possess modular structure, yet the non-local null model used by modularity assigns low probabilities, and thus high significance, to the de...

  16. Processes for non-destructive transfer of graphene: widening the bottleneck for industrial scale production.

    Science.gov (United States)

    Zaretski, Aliaksandr V; Lipomi, Darren J

    2015-06-14

    The exceptional charge-transport, mechanical, and barrier properties of graphene are well known. High-quality films of single-layer graphene produced over large areas, however, are extremely expensive. The high cost of graphene precludes its use in industries-such as transparent electrodes and flexible packaging-that might take full advantage of its properties. This minireview presents several strategies for the transfer of graphene from the substrates used for growth to substrates used for the final application. Each strategy shares the characteristic of being non-destructive: that is, the growth substrate remains reusable for further synthesis of new graphene. These processes have the potential to lower significantly the costs of manufacturing graphene, to increase production yields, and to minimize environmental impact. This article is divided into sections on (i) the synthesis of high-quality single-layer graphene and (ii) its non-destructive transfer to a host substrate. Section (ii) is further divided according to the substrate from which graphene is transferred: single-crystalline wafers or flexible copper foils. We also comment, wherever possible, on defects produced as a result of the transfer, and potential strategies to mitigate these defects. We conclude that several methods for the green synthesis and transfer of graphene have several of the right characteristics to be useful in industrial scale production.

  17. Bottlenecks in the Efficient Use of Advanced Therapy Medicinal Products Based on Mesenchymal Stromal Cells

    Directory of Open Access Journals (Sweden)

    Natalia Escacena

    2015-01-01

    Full Text Available Mesenchymal stromal cells (MSCs have been established as promising candidate sources of universal donor cells for cell therapy due to their contributions to tissue and organ homeostasis, repair, and support by self-renewal and multidifferentiation, as well as by their anti-inflammatory, antiproliferative, immunomodulatory, trophic, and proangiogenic properties. Various diseases have been treated by MSCs in animal models. Additionally, hundreds of clinical trials related to the potential benefits of MSCs are in progress. However, although all MSCs are considered suitable to exert these functions, dissimilarities have been found among MSCs derived from different tissues. The same levels of efficacy and desired outcomes have not always been achieved in the diverse studies that have been performed thus far. Moreover, autologous MSCs can be affected by the disease status of patients, compromising their use. Therefore, collecting information regarding the characteristics of MSCs obtained from different sources and the influence of the host (patient medical conditions on MSCs is important for assuring the safety and efficacy of cell-based therapies. This review provides relevant information regarding factors to consider for the clinical application of MSCs.

  18. Bottlenecks in the Efficient Use of Advanced Therapy Medicinal Products Based on Mesenchymal Stromal Cells.

    Science.gov (United States)

    Escacena, Natalia; Quesada-Hernández, Elena; Capilla-Gonzalez, Vivian; Soria, Bernat; Hmadcha, Abdelkrim

    2015-01-01

    Mesenchymal stromal cells (MSCs) have been established as promising candidate sources of universal donor cells for cell therapy due to their contributions to tissue and organ homeostasis, repair, and support by self-renewal and multidifferentiation, as well as by their anti-inflammatory, antiproliferative, immunomodulatory, trophic, and proangiogenic properties. Various diseases have been treated by MSCs in animal models. Additionally, hundreds of clinical trials related to the potential benefits of MSCs are in progress. However, although all MSCs are considered suitable to exert these functions, dissimilarities have been found among MSCs derived from different tissues. The same levels of efficacy and desired outcomes have not always been achieved in the diverse studies that have been performed thus far. Moreover, autologous MSCs can be affected by the disease status of patients, compromising their use. Therefore, collecting information regarding the characteristics of MSCs obtained from different sources and the influence of the host (patient) medical conditions on MSCs is important for assuring the safety and efficacy of cell-based therapies. This review provides relevant information regarding factors to consider for the clinical application of MSCs.

  19. Bottleneck Analysis on the DoD Pre-Milestone B Acquisition Processes

    OpenAIRE

    Worger, Danielle; Wu, Teresa; Jalao, Eugene Rex; Auger, Christopher; Baldus, Lars; Yoshimoto, Brian; Wirthlin, J. Robert; Colombi, John

    2013-01-01

    Excerpt from the Proceedings of the Tenth Annual Acquisition Research Symposium Acquisition Management Disclaimer: The views represented in this report are those of the authors and do not reflect the official policy position of the Navy, the Department of Defense, or the federal government. The research presented in this report was supported by the Acquisition Research Program of the Graduate School of Business & Public Policy at the Naval Postgraduate School. To request defens...

  20. Bottlenecks in the Transferability of Antibiotic Resistance from Natural Ecosystems to Human Bacterial Pathogens

    OpenAIRE

    Martínez, José L.

    2012-01-01

    It is generally accepted that resistance genes acquired by human pathogens through horizontal gene transfer originated in environmental, non-pathogenic bacteria. As a consequence, there is increasing concern on the roles that natural, non-clinical ecosystems, may play in the evolution of resistance. Recent studies have shown that the variability of determinants that can provide antibiotic resistance on their expression in a heterologous host is much larger than what is actually found in human...

  1. Bottlenecks in the transmission of antibiotic resistance from natural ecosystems to human bacterial pathogens

    OpenAIRE

    Martinez, Jose L.

    2012-01-01

    It is generally accepted that resistance genes acquired by human pathogens trough horizontal gene transfer have been originated in environmental, non pathogenic bacteria. As the consequence, there exists an increasing concern on the role that natural, non-clinical ecosystems, may play on the evolution of resistance. Recent studies have shown that the variability of determinants that can provide antibiotic resistance upon their expression in a heterologous host is much larger than what is actu...

  2. Kinetic bottlenecks to chemical exchange rates for deep-sea animals – Part 1: Oxygen

    Directory of Open Access Journals (Sweden)

    E. T. Peltzer

    2012-10-01

    Full Text Available Ocean warming will reduce dissolved oxygen concentrations which can pose challenges to marine life. Oxygen limits are traditionally reported simply as a static concentration thresholds with no temperature, pressure or flow rate dependency. Here we treat the oceanic oxygen supply potential for heterotrophic consumption as a dynamic molecular exchange problem analogous to familiar gas exchange processes at the sea surface. A combination of the purely physico-chemical oceanic properties temperature, hydrostatic pressure, and oxygen concentration defines the ability of the ocean to supply oxygen to any given animal. This general oceanic oxygen supply potential is modulated by animal specific properties such as the diffusive boundary layer thickness to define and limit maximal oxygen supply rates. Here we combine all these properties into formal, mechanistic equations defining novel oceanic properties that subsume various relevant classical oceanographic parameters to better visualize, map, comprehend, and predict the impact of ocean deoxygenation on aerobic life. By explicitly including temperature and hydrostatic pressure into our quantities, various ocean regions ranging from the cold deep-sea to warm, coastal seas can be compared. We define purely physico-chemical quantities to describe the oceanic oxygen supply potential, but also quantities that contain organism-specific properties which in a most generalized way describe general concepts and dependencies. We apply these novel quantities to example oceanic profiles around the world and find that temperature and pressure dependencies of diffusion and partial pressure create zones of greatest physical constriction on oxygen supply typically at around 1000 m depth, which coincides with oxygen concentration minimum zones. In these zones, which comprise the bulk of the world ocean, ocean warming and deoxygenation have a clear negative effect for aerobic life. In some shallow and warm waters the enhanced diffusion and higher partial pressure due to higher temperatures might slightly overcompensate for oxygen concentration decreases due to decreases in solubility.

  3. Surviving in Changing Seascapes: Sediment Dynamics as Bottleneck for Long-Term Seagrass Presence

    NARCIS (Netherlands)

    Suykerbuyk, W.; Bouma, T.J.; Govers, L.L.; Giesen, K.; de Jong, D.J.; Herman, P.M.J.; Hendriks, J.; van Katwijk, M.M.

    2016-01-01

    Changes in the seascape often result in altered hydrodynamics that lead to coinciding changes in sediment dynamics. Little is known on how altered sediment dynamics affect long-term seagrass persistence. We studied the thresholds of sediment dynamics in relation to seagrass presence by comparing sed

  4. Surviving in changing seascapes : Sediment dynamics as bottleneck for long-term seagrass presence

    NARCIS (Netherlands)

    Suykerbuyk, Wouter; Bouma, Tjeerd J.; Govers, Laura L.; Giesen, Kris; de Jong, Dick J.; Herman, Peter; Hendriks, Jan; van Katwijk, Marieke M.

    2016-01-01

    Changes in the seascape often result in altered hydrodynamics that lead to coinciding changes in sediment dynamics. Little is known on how altered sediment dynamics affect long-term seagrass persistence. We studied the thresholds of sediment dynamics in relation to seagrass presence by comparing sed

  5. Solid-Set Sprinkler Irrigation Controllers Driven by Simulation Models: Opportunities and Bottlenecks

    OpenAIRE

    Playán Jubillar, Enrique; Salvador Esteban, Raquel; López Marín, Cristina; Lecina Brau, Sergio; Dechmi, Farida; Zapata Ruiz, Nery

    2013-01-01

    Farmers continue to show great differences in irrigation water use, even for a given location and crop. Irrigation advisory services have narrowed the gap between scientific knowledge and on-farm scheduling, but their success has been limited. The performance of sprinkler irrigation is greatly affected by factors such as wind speed, whose short-time variability requires tactical adjustments of the irrigation schedule. Mounting energy costs often require the consideration of interday and intra...

  6. Pushing away the communication bottleneck with optical interconnects in symmetric multiprocessors

    Science.gov (United States)

    Hlayhel, Wissam; Collet, Jacques H.; Rochange, Christine; Litaize, Daniel

    2000-05-01

    We analyze the bandwidth needed for transmitting the addresses in future symmetric multiprocessor machines (SMP), constructed around a shared bus due to the critical obligation to preserve the coherence of the memory hierarchy. We show that an address-transaction bandwidth as high as several hundreds of Gbit/s will be necessary not to slow down the execution of most applications in large SMP's. This communication bandwidth seems incompatible with the operation constraints of shared electrical busses, making necessary the search for other implementations of the address transmission network. We consider the introduction of optical interconnects (OI) in this context. We review several solutions, in the ascending order of complexity of the optical subsystems as one critical issue concerns the degree of sophistication of the optical solutions and their cost. We first consider simple point to point OI's for a SMP chipset. The interest for OI's comes from the low energy consumption and from the possibility, in the future, to integrate several thousands of optical input/outputs per electronic chip. The we consider the implementation of an optical bus that is a multipoint optical line involving more optical functionality. We discuss the possibility of multiple accesses to the bus, and the constraints related to the necessity to maintain the coherence of caches.

  7. Recombinant plant-derived pharmaceutical proteins: current technical and economic bottlenecks.

    Science.gov (United States)

    Sabalza, Maite; Christou, Paul; Capell, Teresa

    2014-12-01

    Molecular pharming is a cost-effective platform for the production of recombinant proteins in plants. Although the biopharmaceutical industry still relies on a small number of standardized fermentation-based technologies for the production of recombinant proteins there is now a greater awareness of the advantages of molecular pharming particularly in niche markets. Here we discuss some of the technical, economic and regulatory barriers that constrain the clinical development and commercialization of plant-derived pharmaceutical proteins. We also discuss strategies to increase productivity and product quality/homogeneity. The advantages of whole plants should be welcomed by the industry because this will help to reduce the cost of goods and therefore expand the biopharmaceutical market into untapped sectors. PMID:25048244

  8. Relative quantification in seed GMO analysis: state of art and bottlenecks.

    Science.gov (United States)

    Chaouachi, Maher; Bérard, Aurélie; Saïd, Khaled

    2013-06-01

    Reliable quantitative methods are needed to comply with current EU regulations on the mandatory labeling of genetically modified organisms (GMOs) and GMO-derived food and feed products with a minimum GMO content of 0.9 %. The implementation of EU Commission Recommendation 2004/787/EC on technical guidance for sampling and detection which meant as a helpful tool for the practical implementation of EC Regulation 1830/2003, which states that "the results of quantitative analysis should be expressed as the number of target DNA sequences per target taxon specific sequences calculated in terms of haploid genomes". This has led to an intense debate on the type of calibrator best suitable for GMO quantification. The main question addressed in this review is whether reference materials and calibrators should be matrix based or whether pure DNA analytes should be used for relative quantification in GMO analysis. The state of the art, including the advantages and drawbacks, of using DNA plasmid (compared to genomic DNA reference materials) as calibrators, is widely described. In addition, the influence of the genetic structure of seeds on real-time PCR quantitative results obtained for seed lots is discussed. The specific composition of a seed kernel, the mode of inheritance, and the ploidy level ensure that there is discordance between a GMO % expressed as a haploid genome equivalent and a GMO % based on numbers of seeds. This means that a threshold fixed as a percentage of seeds cannot be used as such for RT-PCR. All critical points that affect the expression of the GMO content in seeds are discussed in this paper.

  9. Bottlenecks in the prediction of regioselectivity of [4 + 2] cycloaddition reactions: An assessment of reactivity descriptors

    Indian Academy of Sciences (India)

    G Gayatri; G Narahari Sastry

    2005-09-01

    B3LYP/6-31G() calculations were performed to obtain all the transition states and products for the 128 distinct reaction channels of Diels-Alder reactions by taking all possible combinations from a series of dienes (1N-a, 1N-b, 2N, 1P-a, 1P-b, 2P, 1O, 1S) and dienophiles (NE, PE, OE, SE, AE, OHE, MeE, CNE). The predictive ability of the values to gauge the regioselectivity of the putative [4 + 2] cycloaddition reactions is analysed. No correlation is obtained between the reaction energies and activation energies. The extent of asynchronicity is measured based on the bond order analysis. DFT-based descriptors such as the local softness ($s^{+}_{k}$ and $s_{k}^{-}$), Fukui function indices ($f^{+}_{k}$ and $f_{k}^{-}$), global electrophilicity index () and local electrophilicity index () were found to be better than the conventional FMO predictions.

  10. GWDC Solves World-class Drilling Bottleneck in Kenkijak Oil Field

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ The news that Greatwall Drilling Company Limited (GWDC) has drilled a well with the daily oil production of more than one thousand tons spread quickly when the Well H8010 of CNPC Aktobin Oil and Gas Shareholding Company (CNPC Aktobin) in Kenkijak Oil Field in Kazakhstan produced 1,170 tons on July 1, 2004; both the employees of GWDC and CNPC Aktobin could not hold their excited feeling and cheered at such encouraging news.

  11. HDMI:the Future and Bottlenecks%HDMI:前景与瓶颈并存

    Institute of Scientific and Technical Information of China (English)

    刘洋

    2007-01-01

    HDMI (High-Definition Multimedia Interface)目前似乎是市场上消费电子产品数字视频接口传输标准最流行的一种,其通过一根电缆即可传输高质量的音频和视频信号,预计到2010年,HDMI设备将超过100亿件,最新的HDMI 1.8标准提供两倍的带宽,从而可以舆更高质量的音频和视频信号,显示色觉提高到48bit,能展现更多的色彩和层次,音频的传输也达到7.1声道.

  12. Development of a Workbench to Address the Educational Data Mining Bottleneck

    Science.gov (United States)

    Rodrigo, Ma. Mercedes T.; Baker, Ryan S. J. d.; McLaren, Bruce M.; Jayme, Alejandra; Dy, Thomas T.

    2012-01-01

    In recent years, machine-learning software packages have made it easier for educational data mining researchers to create real-time detectors of cognitive skill as well as of metacognitive and motivational behavior that can be used to improve student learning. However, there remain challenges to overcome for these methods to become available to…

  13. Kinetic bottlenecks to chemical exchange rates for deep-sea animals – Part 2: Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    A. F. Hofmann

    2013-04-01

    Full Text Available Increased ocean acidification from fossil fuel CO2 invasion, from temperature-driven changes in respiration, and from possible leakage from sub-seabed geologic CO2 disposal has aroused concern over the impacts of elevated CO2 concentrations on marine life. Discussion of these impacts has so far focused only on changes in the oceanic bulk fluid properties (ΔpH, Δ[∑ CO2], etc. as the critical variable and with a major focus on carbonate shell formation. Here we describe the rate problem for animals that must export CO2 at about the same rate at which O2 is consumed. We analyse the basic properties controlling CO2 export within the diffusive boundary layer around marine animals in an ocean changing in temperature (T and CO2 concentration in order to compare the challenges posed by O2 uptake under stress with the equivalent problem of CO2 expulsion. The problem is more complex than that for a non-reactive gas, since with CO2 the influence of the seawater carbonate acid-base system needs to be considered. These reactions significantly facilitate CO2 efflux compared to O2 intake at equal temperature, pressure and fluid flow rate under typical oceanic concentrations. The effect of these reactions can be described by an enhancement factor, similar to that widely used for CO2 invasion at the sea surface. While organisms do need to actively regulate flow over their surface to thin the boundary layer to take up enough O2, this seems to be not necessary to facilitate CO2 efflux. Instead, the main impacts of rising oceanic CO2 will most likely be those associated with classical ocean acidification science. Regionally, as with O2, the combination of T, P and pH/pCO2 creates a zone of maximum CO2 stress at around 1000 m depth.

  14. Kinetic bottlenecks to chemical exchange rates for deep-sea animals II: Carbon dioxide

    Directory of Open Access Journals (Sweden)

    A. F. Hofmann

    2012-11-01

    Full Text Available Increased ocean acidification from fossil fuel CO2 invasion, from temperature-driven changes in respiration, and from possible leakage from sub-seabed geologic CO2 disposal has aroused concern over the impacts of elevated CO2 concentrations on marine life. Discussion of these impacts has so far focused only on changes in the oceanic bulk fluid properties (ΔpH, Δ[∑CO2] etc. as the critical variable and with a major focus on carbonate shell dissolution. Here we describe the rate problem for animals that must export CO2 at about the same rate at which O2 is consumed. We analyze the basic properties controlling CO2 export within the diffusive boundary layer around marine animals in an ocean changing in temperature (T and CO2 concentration in order to compare the challenges posed by O2 uptake under stress with the equivalent problem of CO2 expulsion. The problem is more complex than that for a non-reactive gas since, as with gas exchange of CO2 at the air-sea interface, the influence of the ensemble of reactions within the CO2-HCO3-CO32– acid-base system needs to be considered. These reactions significantly facilitate CO2 efflux compared to O2 intake at equal temperature, pressure and flow rate under typical oceanic concentrations.The effect of these reactions can be described by an enhancement factor. For organisms, this means mechanically increasing flow over their surface to thin the boundary layer as is required to alleviate O2 stress seems not necessary to facilitate CO2 efflux. Nevertheless the elevated pCO2 cost most likely is non-zero. Regionally as with O2 the combination of T, P, and pH/pCO2 creates a zone of maximum CO2 stress at around 1000 m depth. But the net result is that, for the problem of gas exchange with the bulk ocean, the combination of an increasing T combined with declining O2 poses a greater challenge to marine life than does increasing CO2. The relationships developed here allow a more accurate prediction of the impacts on marine life from the combined effects of changing T, O2, and CO2 than can be estimated from single variable studies.

  15. Processes for non-destructive transfer of graphene: widening the bottleneck for industrial scale production

    Science.gov (United States)

    Zaretski, Aliaksandr V.; Lipomi, Darren J.

    2015-05-01

    The exceptional charge-transport, mechanical, and barrier properties of graphene are well known. High-quality films of single-layer graphene produced over large areas, however, are extremely expensive. The high cost of graphene precludes its use in industries--such as transparent electrodes and flexible packaging--that might take full advantage of its properties. This minireview presents several strategies for the transfer of graphene from the substrates used for growth to substrates used for the final application. Each strategy shares the characteristic of being non-destructive: that is, the growth substrate remains reusable for further synthesis of new graphene. These processes have the potential to lower significantly the costs of manufacturing graphene, to increase production yields, and to minimize environmental impact. This article is divided into sections on (i) the synthesis of high-quality single-layer graphene and (ii) its non-destructive transfer to a host substrate. Section (ii) is further divided according to the substrate from which graphene is transferred: single-crystalline wafers or flexible copper foils. We also comment, wherever possible, on defects produced as a result of the transfer, and potential strategies to mitigate these defects. We conclude that several methods for the green synthesis and transfer of graphene have several of the right characteristics to be useful in industrial scale production.

  16. Topological-based bottleneck analysis and improvement strategies for traffic networks

    Institute of Scientific and Technical Information of China (English)

    WU JianJun; GAO ZiYou; SUN HuiJun

    2009-01-01

    ck,and make appropriate policies for traffic demand management.Meanwhile,the method has very important theoretical significance and practical worthiness in optimizing traffic organization,traffic control,and disposal of emergency.

  17. Addressing the medicinal chemistry bottleneck: a lean approach to centralized purification.

    Science.gov (United States)

    Weller, Harold N; Nirschl, David S; Paulson, James L; Hoffman, Steven L; Bullock, William H

    2012-09-10

    The use of standardized lean manufacturing principles to improve drug discovery productivity is often thought to be at odds with fostering innovation. This manuscript describes how selective implementation of a lean optimized process, in this case centralized purification for medicinal chemistry, can improve operational productivity and increase scientist time available for innovation. A description of the centralized purification process is provided along with both operational and impact (productivity) metrics, which indicate lower cost, higher output, and presumably more free time for innovation as a result of the process changes described.

  18. Innovations : Perceptions of teachers and school leaders on bottlenecks and outcomes

    NARCIS (Netherlands)

    Hofman, Roelande H.; Jansen, Edine; Spijkerboer, Alma

    2011-01-01

    New legislation was introduced for the lower grades of secondary education in 2006 in the Netherlands. Innovations and reform implemented by schools related to this new legislation focused on new approaches to educational content such as didactical approaches, active learning, project teams, compete

  19. Lessons Learned From Microkernel Verification — Specification is the New Bottleneck

    Directory of Open Access Journals (Sweden)

    Thorsten Bormer

    2012-11-01

    Full Text Available Software verification tools have become a lot more powerful in recent years. Even verification of large, complex systems is feasible, as demonstrated in the L4.verified and Verisoft XT projects. Still, functional verification of large software systems is rare – for reasons beyond the large scale of verification effort needed due to the size alone. In this paper we report on lessons learned for verification of large software systems based on the experience gained in microkernel verification in the Verisoft XT project. We discuss a number of issues that impede widespread introduction of formal verification in the software life-cycle process.

  20. Kinetic bottlenecks to chemical exchange rates for deep-sea animals II: Carbon dioxide

    OpenAIRE

    Hofmann, Andreas F.; Peltzer, Edward T.; Brewer, Peter G.

    2012-01-01

    Increased ocean acidification from fossil fuel CO2 invasion, from temperature-driven changes in respiration, and from possible leakage from sub-seabed geologic CO2 disposal has aroused concern over the impacts of elevated CO2 concentrations on marine life. 5 Discussion of these impacts has so far focused only on changes in the oceanic bulk fluid properties as the critical variable and with a major focus on carbonate shell dissolution. Here we describe the rate problem for anima...

  1. Kinetic bottlenecks to chemical exchange rates for deep-sea animals - Part 2: Carbon Dioxide

    OpenAIRE

    Hofmann, Andreas F.; Peltzer, Edward T.; Brewer, Peter G.

    2013-01-01

    Increased ocean acidification from fossil fuel CO2 invasion, from temperature-driven changes in respiration, and from possible leakage from sub-seabed geologic CO2 disposal has aroused concern over the impacts of elevated CO2 concentrations on marine life. Discussion of these impacts has so far focused only on changes in the oceanic bulk fluid properties (Delta pH, Delta [Sum CO2], etc.) as the critical variable and with a major focus on carbonate shell formation. Here we describe...

  2. Recombinant plant-derived pharmaceutical proteins: current technical and economic bottlenecks.

    Science.gov (United States)

    Sabalza, Maite; Christou, Paul; Capell, Teresa

    2014-12-01

    Molecular pharming is a cost-effective platform for the production of recombinant proteins in plants. Although the biopharmaceutical industry still relies on a small number of standardized fermentation-based technologies for the production of recombinant proteins there is now a greater awareness of the advantages of molecular pharming particularly in niche markets. Here we discuss some of the technical, economic and regulatory barriers that constrain the clinical development and commercialization of plant-derived pharmaceutical proteins. We also discuss strategies to increase productivity and product quality/homogeneity. The advantages of whole plants should be welcomed by the industry because this will help to reduce the cost of goods and therefore expand the biopharmaceutical market into untapped sectors.

  3. Bottlenecks in the transmission of antibiotic resistance from natural ecosystems to human bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Jose L Martinez

    2012-01-01

    Full Text Available It is generally accepted that resistance genes acquired by human pathogens trough horizontal gene transfer have been originated in environmental, non pathogenic bacteria. As the consequence, there exists an increasing concern on the role that natural, non-clinical ecosystems, may play on the evolution of resistance. Recent studies have shown that the variability of determinants that can provide antibiotic resistance upon their expression in a heterologous host is much larger than what is actually found in human pathogens. Along the review, the role that different processes as founder effect, ecological connectivity, fitness costs or second-order selection may have on the establishment of a specific resistance determinant in the population of bacterial pathogens is analysed.

  4. Impact of population structure, effective bottleneck time, and allele frequency on linkage disequilibrium maps

    OpenAIRE

    Zhang, Weihua; Collins, Andrew; Gibson, Jane; Tapper, William J; Hunt, Sarah; Deloukas, Panos; Bentley, David R.; Morton, Newton E.

    2004-01-01

    Genetic maps in linkage disequilibrium (LD) units play the same role for association mapping as maps in centimorgans provide at much lower resolution for linkage mapping. Association mapping of genes determining disease susceptibility and other phenotypes is based on the theory of LD, here applied to relations with three phenomena. To test the theory, markers at high density along a 10-Mb continuous segment of chromosome 20q were studied in African-American, Asian, and Caucasian samples. Popu...

  5. The potential for price co-operation in a hydroelectric power market with temporary bottlenecks

    International Nuclear Information System (INIS)

    The report discusses whether there is a larger potential for coordinated price stipulation in a hydropower market that periodically has limitations in the transmission capacity. Such limitations in the transmission capacities transform an integrated market into lesser market segments and this will be reflected in price differences between the segments. The total production in a power market with hydropower producers is dependent on the afflux. Hydropower producers with storage capacities have a large flexibility with respect to power production because the water in a water reservoir may be stored until the production period. Depending on the theoretical model in use the discount factor for coordinated price stipulation will be lower in a hydropower market with periodical limitations in the transmission capacities than in an integrated power market with optimal production adaptation

  6. Multitasking or Continuous Partial Attention: A Critical Bottleneck for Digital Natives

    Science.gov (United States)

    Firat, Mehmet

    2013-01-01

    With the beginning of the second half of the past century, advances in Information and Communication Technologies had unprecedented influence deeply felt in all social structures. The effects were so much widespread that the differences in technology use have created a huge gap between generations in terms of everyday life and lifestyle. As a…

  7. MULTITASKING OR CONTINUOUS PARTIAL ATTENTION: A CRITICAL BOTTLENECK FOR DIGITAL NATIVES

    Directory of Open Access Journals (Sweden)

    Mehmet FIRAT

    2013-01-01

    Full Text Available With the beginning of the second half of the past century, advances in Information and Communication Technologies had unprecedented influence deeply felt in all social structures. The effects were so much widespread that the differences in technology use have created a huge gap between generations in terms of everyday life and lifestyle. As a result, two groups occurred; those growing with technology digital natives and digital immigrants who try to keep pace with technology. Today, the computer, internet and mobile technologies like e-book readers, mobile phones, android devices, smart phones and tablet computers have become all-day business and communication tools used by digital natives. However, these high-tech tools, with their speed and ease of use, revealed some important issues that deeply affect digital natives' way of life. Among these most important effects are Continuous Partial Attention and Multitasking. In this study, these two conditions faced by digital natives were compared, and some suggestions have been put forward for the digital native learners.

  8. Inferring bottlenecks from genome-wide samples of short sequence blocks

    NARCIS (Netherlands)

    Bunnefeld, Lynsey; Frantz, Laurent A.F.; Lohse, Konrad

    2015-01-01

    The advent of the genomic era has necessitated the development of methods capable of analyzing large volumes of genomic data efficiently. Being able to reliably identify bottlenecks—extreme population size changes of short duration—not only is interesting in the context of speciation and extincti

  9. Out of the bottleneck: the Diversity Outcross and Collaborative Cross mouse populations in behavioral genetics research.

    Science.gov (United States)

    Chesler, Elissa J

    2014-02-01

    The historical origins of classical laboratory mouse strains have led to a relatively limited range of genetic and phenotypic variation, particularly for the study of behavior. Many recent efforts have resulted in improved diversity and precision of mouse genetic resources for behavioral research, including the Collaborative Cross and Diversity Outcross population. These two populations, derived from an eight way cross of common and wild-derived strains, have high precision and allelic diversity. Behavioral variation in the population is expanded, both qualitatively and quantitatively. Variation that had once been canalized among the various inbred lines has been made amenable to genetic dissection. The genetic attributes of these complementary populations, along with advances in genetic and genomic technologies, makes a systems genetic analyses of behavior more readily tractable, enabling discovery of a greater range of neurobiological phenomena underlying behavioral variation.

  10. Floods, Bottlenecks and Backwaters: An Analysis of Expansion in Higher Education in Norway.

    Science.gov (United States)

    Aamodt, Per O.

    1995-01-01

    Discussion of the pressures for expansion in Norwegian higher education looks at both long-term trends (need for a better-educated workforce and rising level in parents' education) and current demographic, individual, and political forces (a deteriorating labor market, younger students, competition for admission). Whether this situation is unique…

  11. Overcoming the matched-sample bottleneck: an orthogonal approach to integrate omic data.

    Science.gov (United States)

    Nguyen, Tin; Diaz, Diana; Tagett, Rebecca; Draghici, Sorin

    2016-01-01

    MicroRNAs (miRNAs) are small non-coding RNA molecules whose primary function is to regulate the expression of gene products via hybridization to mRNA transcripts, resulting in suppression of translation or mRNA degradation. Although miRNAs have been implicated in complex diseases, including cancer, their impact on distinct biological pathways and phenotypes is largely unknown. Current integration approaches require sample-matched miRNA/mRNA datasets, resulting in limited applicability in practice. Since these approaches cannot integrate heterogeneous information available across independent experiments, they neither account for bias inherent in individual studies, nor do they benefit from increased sample size. Here we present a novel framework able to integrate miRNA and mRNA data (vertical data integration) available in independent studies (horizontal meta-analysis) allowing for a comprehensive analysis of the given phenotypes. To demonstrate the utility of our method, we conducted a meta-analysis of pancreatic and colorectal cancer, using 1,471 samples from 15 mRNA and 14 miRNA expression datasets. Our two-dimensional data integration approach greatly increases the power of statistical analysis and correctly identifies pathways known to be implicated in the phenotypes. The proposed framework is sufficiently general to integrate other types of data obtained from high-throughput assays. PMID:27403564

  12. Looking through phonological shape to lexical meaning: the bottleneck of non-native sign language processing.

    Science.gov (United States)

    Mayberry, R I; Fischer, S D

    1989-11-01

    In two studies, we find that native and non-native acquisition show different effects on sign language processing. Subjects were all born deaf and used sign language for interpersonal communication, but first acquired it at ages ranging from birth to 18. In the first study, deaf signers shadowed (simultaneously watched and reproduced) sign language narratives given in two dialects, American Sign Language (ASL) and Pidgin Sign English (PSE), in both good and poor viewing conditions. In the second study, deaf signers recalled and shadowed grammatical and ungrammatical ASL sentences. In comparison with non-native signers, natives were more accurate, comprehended better, and made different kinds of lexical changes; natives primarily changed signs in relation to sign meaning independent of the phonological characteristics of the stimulus. In contrast, non-native signers primarily changed signs in relation to the phonological characteristics of the stimulus independent of lexical and sentential meaning. Semantic lexical changes were positively correlated to processing accuracy and comprehension, whereas phonological lexical changes were negatively correlated. The effects of non-native acquisition were similar across variations in the sign dialect, viewing condition, and processing task. The results suggest that native signers process lexical structural automatically, such that they can attend to and remember lexical and sentential meaning. In contrast, non-native signers appear to allocate more attention to the task of identifying phonological shape such that they have less attention available for retrieval and memory of lexical meaning.

  13. Bottleneck of using single memristor as a synapse and its solution

    CERN Document Server

    Merrikh-Bayat, Farnood

    2010-01-01

    Physical realization of the first memristor by researchers at Hewlett Packard (HP) labs attracts so much interest in this newly found circuit element which has so many applications specially in a field of neuromorphic systems. Now, it is well known that one of the main applications of memristor is for the hardware implementation of synapses because of their capability in dense fabrication and acting as a perfect analog memory. However, synapses in biological systems have this property that by progressing in the learning process, variation rate of the synapses weights should decrease which is not the case in the currently suggested memristor-based structures of neuromorphic systems. In this paper, we show that using two dissimilar memristors connected in series as a synapse perform better than the single memristor.

  14. Bottleneck Surfaces and Worldsheet Geometry of Higher-Curvature Quantum Gravity

    CERN Document Server

    Szabó, R J; Szabo, Richard J.; Wheater, John F.

    2000-01-01

    We describe a simple lattice model of higher-curvature quantum gravity in two dimensions and study the phase structure of the theory as a function of the curvature coupling. It is shown that the ensemble of flat graphs is entropically unstable to the formation of baby universes. In these simplified models the growth in graphs exhibits a branched polymer behaviour in the phase directly before the flattening transition.

  15. No severe bottleneck during human evolution: evidence from two apolipoprotein C-II deficiency alleles.

    OpenAIRE

    Xiong, W J; Li, W. H.; Posner, I; Yamamura, T.; Yamamoto, A.; Gotto, A M; Chan, L

    1991-01-01

    The DNA sequences of a Japanese and a Venezuelan apolipoprotein (apo) C-II deficiency allele, of a normal Japanese apo C-II gene, and of a chimpanzee apo C-II gene were amplified by PCR, and their nucleotide sequences were determined on multiple clones of the PCR products. The normal Japanese sequence is identical to--and the chimpanzee sequence differs by only three nucleotides from--a previously published normal Caucasian sequence. In contrast, the two human mutant sequences each differ fro...

  16. Meta-Analysis of mitochondrial DNA reveals several population bottlenecks during worldwide migrations of cattle

    NARCIS (Netherlands)

    Lenstra, Johannes A.; Ajmone-Marsan, Paolo; Beja-Pereira, Albano; Bollongino, Ruth; Bradley, Daniel G.; Colli, Licia; De Gaetano, Anna; Edwards, Ceiridwen J.; Felius, Marleen; Ferretti, Luca; Ginja, Catarina; Hristov, Peter; Kantanen, Juha; Lirón, Juan Pedro; Magee, David A.; Negrini, Riccardo; Radoslavov, Georgi A.

    2014-01-01

    Several studies have investigated the differentiation of mitochondrial DNA in Eurasian, African and American cattle as well as archaeological bovine material. A global survey of these studies shows that haplogroup distributions are more stable in time than in space. All major migrations of cattle ha

  17. Flow rate of polygonal grains through a bottleneck: Interplay between shape and size

    Directory of Open Access Journals (Sweden)

    Ezequiel Goldberg

    2015-11-01

    Full Text Available We report two-dimensional simulations of circular and polygonal grains passing through an aperture at the bottom of a silo. The mass flow rate for regular polygons is lower than for disks\\red{,} as observed by other authors. We show that both the exit velocity of the grains and the packing fraction are lower for polygons, which leads to the reduced flow rate. We point out the importance of the criteria used to define when two objects of different shape are considered to be of the same size. Depending on this criteria, the mass flow rate may vary significantly for some polygons. Moreover, the particle flow rate is non-trivially related to a combination of mass flow rate, particle shape and particle size. For some polygons, the particle flow rate may be lower or higher than that of the corresponding disks depending on the size comparison criteria. Received: 18 May 2015, Accepted: 30 October 2015; Edited by: F. Melo; Reviewed by: J.-N. Roux, Universite Parsi Est, Laboratoire Navier, Champs-sur-Marne, France; DOI: http://dx.doi.org/10.4279/PIP.070016 Cite as: E Goldberg, C M Carlevaro, L A Pugnaloni, Papers in Physics 7, 070016 (2015

  18. Costa Rica, superstar? some reflections on the global drivers and bottlenecks of the happy planet index

    OpenAIRE

    Tausch, Arno

    2011-01-01

    For some years now, the Happy Planet Organization presents the so-called ‘Happy Planet Index’ (HPI), which is an index of measuring the trade-off between ecological footprint data and life quality (Happy Life Years, HLYE). Costa Rica emerges from these comparisons as the world’s ‘best practice nation’, using a minimum amount of natural resources to achieve a maximum of human happiness. So is Costa Rica the pathway for humanity? There are shortcomings in the formula, with which the index is ca...

  19. Globalization as a driver or bottleneck for sustainable development. General tendencies and European implications

    OpenAIRE

    Tausch, Arno

    2011-01-01

    This article looks at the long-term, structural determinants of environmental performance in the world system. In multiple standard OLS regression models, we test the effects of 26 standard predictor variables, including the ‘four freedoms’ of goods, capital, labour and services, on the following indicators of sustainable development • avoiding net trade of ecological footprint gha per person • Carbon emissions per million US dollars GDP • CO2 per capita • Environmental Performa...

  20. Performance Modeling of a Bottleneck Node in an IEEE 802.11 Ad-hoc Network

    NARCIS (Netherlands)

    Berg, van den Hans; Roijers, Frank; Mandjes, Michel R.H.; Kunz, T.; Ravi, S.S.

    2006-01-01

    The IEEE 802.11 MAC protocol, often used in ad-hoc networks, has the tendency to share the capacity equally amongst the active nodes, irrespective of their loads. An inherent drawback of this fair-sharing policy is that a node that serves as a relay-node for multiple flows is likely to become a bott

  1. Dynamic bottleneck optimization for k-edge and 2-vertex connectivity

    DEFF Research Database (Denmark)

    Telelis, Orestis; Zissimopoulos, Vassilis

    2008-01-01

    We consider the problem of updating efficiently the minimum value b over a weighted graph, so that edges with a cost less than b induce a spanning subgraph satisfying a k-edge or 2-vertex connectivity constraint, when the cost of an edge of the graph is updated. Our results include update algorit...

  2. Performance modelieg of a bottleneck node in an IEEE 802.11 ad-hoc network

    NARCIS (Netherlands)

    Berg, J.L. van den; Mandjes, M.; Roijers, F.

    2006-01-01

    The IEEE 802.11 MAC-protocol, often used in ad-hoc networks, has the tendency to share the capacity equally amongst the active nodes, irrespective of their loads. An inherent drawback of this fair-sharing policy is that a node that serves as a relay-node for multiple flows is likely to become a bott

  3. Land, Fund and Mechanism: Three Bottlenecks of Chinese Urban Forestry in the 21st Century

    Institute of Scientific and Technical Information of China (English)

    LIU Deliang; LI jiyue; ZUO Jiafu

    2006-01-01

    Although desirable developments have been achieved since the implementation of the reform-and-opening-up policy, the urban forestry in China is still haunted by the problems of land scarcity, fund shortage and administrative mechanism dysfunction. With a concern of these problems, this paper have made a survey of the current status of the land use in urban areas for the purpose of proposing strategies for urban forestry development in China, and have made an evaluation on the relation between fund and urban forestry with a focus on the means of attracting investment and raising fund. In line with the system of social organizations, of administration, and of management, special concern about the systematic and operational mechanism of urban forestry has been expressed. Based upon the analysis as such, this paper holds that land is the foundation of urban forestry development; fund is the motive force of the sustainable development of urban forestry; mechanism is the guarantee for the urban forestry to develop in a healthy and effective order.

  4. Photosynthesis driven crop growth models for greenhouse cultivation; advances and bottlenecks.

    NARCIS (Netherlands)

    Challa, H.; Heuvelink, E.

    1996-01-01

    In recent years considerable progress has been made in modelling growth of green-house crops. Nevertheless, the share of research in this field compared to crop modelling in general is only a few percent. Yet, crop growth models have a great potential for greenhouse production systems, because they

  5. Photosynthesis driven crop growth models for greenhouse cultivation; advances and bottlenecks.

    OpenAIRE

    Challa, H.; Heuvelink, E.

    1996-01-01

    In recent years considerable progress has been made in modelling growth of green-house crops. Nevertheless, the share of research in this field compared to crop modelling in general is only a few percent. Yet, crop growth models have a great potential for greenhouse production systems, because they are characterised by a high degree of complexity, intensity and diversity. Therefore it is important that crop growth models find a wider application in research and in practice. To achieve a wider...

  6. Surviving in Changing Seascapes: Sediment Dynamics as Bottleneck for Long-Term Seagrass Presence

    OpenAIRE

    Suykerbuyk, W.; Bouma, T.J.; Govers, L.L.; Giesen, K.; de Jong, D J; Herman, P.M.J.; Hendriks, J.; van Katwijk, M. M.

    2016-01-01

    Changes in the seascape often result in altered hydrodynamics that lead to coinciding changes in sediment dynamics. Little is known on how altered sediment dynamics affect long-term seagrass persistence. We studied the thresholds of sediment dynamics in relation to seagrass presence by comparing sediment characteristics and seagrass presence data of seven separate seagrass meadows. All meadows had a long-term (>20 years) presence. Within these meadows, we distinguish so-called “hotspots” (are...

  7. Recovery of valuable nitrogen compounds from agricultural liquid wastes: potential possibilities, bottlenecks and future technological challenges.

    NARCIS (Netherlands)

    Rulkens, W.H.; Klapwijk, A.; Willers, H.C.

    1998-01-01

    Agricultural liquid livestock wastes are an important potential source of valuable nitrogen-containing compounds such as ammonia and proteins. Large volumetric quantities of these wastes are produced in areas with a high livestock production density. Much technological research has been carried out

  8. 中欧经贸关系:特色、瓶颈与破解之道%The Characteristics and Bottle-Neck in China-EU Trade Relationship and How to Break this Bottle-Neck

    Institute of Scientific and Technical Information of China (English)

    周文贵

    2006-01-01

    本文认为,中欧建交以来,双边经贸关系的发展保持着良好的势头,成绩巨大,并且凸显出别具一格的特色.但当前中欧经贸关系的发展也的确遇到了一些亟待突破的"瓶颈",诸如中国的市场经济国家地位问题、欧盟实施贸易保护主义措施问题、对华贸易逆差问题等.文章提出,目前需要的是充分认识到中欧双方客观存在的共同利益,着眼于发展战略合作伙伴关系的大局,本着互利双赢的原则,积极谋划破解之道,冲破"瓶颈",推动中欧经贸关系向纵深发展.

  9. The rate of food processing in the Oystercatcher : Food intake and energy expenditure constrained by a digestive bottleneck

    NARCIS (Netherlands)

    Kersten, M

    1996-01-01

    1. Whether food intake is determined by the maximum rate at which animals can collect food, or by the rate at which this food can be processed, will strongly affect the organization of their behaviour. We investigated whether the digestive system imposes a constraint on (I) instantaneous rate of foo

  10. Could nutrition sensitive cocoa value chains be introduced in Ghana? Report of a brief study that identifies opportunities and bottlenecks

    NARCIS (Netherlands)

    Vries, de K.

    2015-01-01

    This study looks at whether introducing nutrition sensitive cocoa value chains in Ghana is feasible and recommends how this could be done. After establishing the cocoa farming and nutrition context in Ghana, the study zooms in on one cocoa producing sub-district to collect detailed data in order to

  11. Insertional mutagenesis and deep profiling reveals gene hierarchies and a Myc/p53-dependent bottleneck in lymphomagenesis.

    Science.gov (United States)

    Huser, Camille A; Gilroy, Kathryn L; de Ridder, Jeroen; Kilbey, Anna; Borland, Gillian; Mackay, Nancy; Jenkins, Alma; Bell, Margaret; Herzyk, Pawel; van der Weyden, Louise; Adams, David J; Rust, Alistair G; Cameron, Ewan; Neil, James C

    2014-02-01

    Retroviral insertional mutagenesis (RIM) is a powerful tool for cancer genomics that was combined in this study with deep sequencing (RIM/DS) to facilitate a comprehensive analysis of lymphoma progression. Transgenic mice expressing two potent collaborating oncogenes in the germ line (CD2-MYC, -Runx2) develop rapid onset tumours that can be accelerated and rendered polyclonal by neonatal Moloney murine leukaemia virus (MoMLV) infection. RIM/DS analysis of 28 polyclonal lymphomas identified 771 common insertion sites (CISs) defining a 'progression network' that encompassed a remarkably large fraction of known MoMLV target genes, with further strong indications of oncogenic selection above the background of MoMLV integration preference. Progression driven by RIM was characterised as a Darwinian process of clonal competition engaging proliferation control networks downstream of cytokine and T-cell receptor signalling. Enhancer mode activation accounted for the most efficiently selected CIS target genes, including Ccr7 as the most prominent of a set of chemokine receptors driving paracrine growth stimulation and lymphoma dissemination. Another large target gene subset including candidate tumour suppressors was disrupted by intragenic insertions. A second RIM/DS screen comparing lymphomas of wild-type and parental transgenics showed that CD2-MYC tumours are virtually dependent on activation of Runx family genes in strong preference to other potent Myc collaborating genes (Gfi1, Notch1). Ikzf1 was identified as a novel collaborating gene for Runx2 and illustrated the interface between integration preference and oncogenic selection. Lymphoma target genes for MoMLV can be classified into (a) a small set of master regulators that confer self-renewal; overcoming p53 and other failsafe pathways and (b) a large group of progression genes that control autonomous proliferation in transformed cells. These findings provide insights into retroviral biology, human cancer genetics and the safety of vector-mediated gene therapy. PMID:24586197

  12. Marine neurotoxins: state of the art, bottlenecks, and perspectives for mode of action based methods of detection in seafood.

    Science.gov (United States)

    Nicolas, Jonathan; Hendriksen, Peter J M; Gerssen, Arjen; Bovee, Toine F H; Rietjens, Ivonne M C M

    2014-01-01

    Marine biotoxins can accumulate in fish and shellfish, representing a possible threat for consumers. Many marine biotoxins affect neuronal function essentially through their interaction with ion channels or receptors, leading to different symptoms including paralysis and even death. The detection of marine biotoxins in seafood products is therefore a priority. Official methods for control are often still using in vivo assays, such as the mouse bioassay. This test is considered unethical and the development of alternative assays is urgently required. Chemical analyses as well as in vitro assays have been developed to detect marine biotoxins in seafood. However, most of the current in vitro alternatives to animal testing present disadvantages: low throughput and lack of sensitivity resulting in a high number of false-negative results. Thus, there is an urgent need for the development of new in vitro tests that would allow the detection of marine biotoxins in seafood products at a low cost, with high throughput combined with high sensitivity, reproducibility, and predictivity. Mode of action based in vitro bioassays may provide tools that fulfil these requirements. This review covers the current state of the art of such mode of action based alternative assays to detect neurotoxic marine biotoxins in seafood. PMID:24311541

  13. Incorporation of public hospitals: a "silver bullet" against overcapacity, managerial bottlenecks and resource constraints? Case studies from Austria and Estonia.

    Science.gov (United States)

    Fidler, Armin H; Haslinger, Reinhard R; Hofmarcher, Maria M; Jesse, Maris; Palu, Toomas

    2007-05-01

    This paper presents a new approach for incorporating public hospitals by contrasting the experience from an "old" EU country (Austria) with a new EU member state (Estonia). In the EU (including the new member states) hospital overcapacity is a serious problem, from a technical, fiscal and political perspective. Few countries have succeeded in establishing an appropriate framework for resource management and for guaranteeing long-term financial viability of their hospital network. Many countries are in search of effective policies for improved hospital management and more cost-effective resource use in the health sector. Over the past decade, experiences in Austria and Estonia have emerged as innovative examples which may provide lessons for other EU countries and beyond. This paper describes the evolution of public hospitals from public budgetary units and public management to incorporated autonomous organizations under private corporate law, resulting in a contractual relationship between (public) owners and private hospital management. Outdated and inefficient public sector structures were replaced by more agile corporate management. The arrangement allows for investments, operating costs and budgeting according to strategic business goals as opposed to political "fiat". Shielding hospitals from local political influence is an important aspect of this concept. Horizontal integration through networking of public hospitals and introducing private management helps create a new corporate culture, allowing for more flexibility to achieve efficiencies through downsizing and economies of scale. Based on contracts the new balance between ownership and managerial functions create strong incentives for a more business-like, results-oriented and consumer-friendly management. This was achieved both in Austria and Estonia in a politically sensitive way, adopting a long-term vision and by protecting the interests of hospital owners and staff. PMID:16919838

  14. Digestive bottleneck affects foraging decisions in red knots Calidris canutus. II. Patch choice and length of working day

    NARCIS (Netherlands)

    Van Gils, JA; Dekinga, A; Spaans, B; Vahl, WK; Piersma, T

    2005-01-01

    1. When prey occur at high densities, energy assimilation rates are generally constrained by rates of digestion rather than by rates of collection (i.e. search and handle). As predators usually select patches containing high prey densities, rates of digestion will play an important role in the forag

  15. Process-induced Distortions in CFRP Manufacturing: A bottle-neck for high-rate Production Scenarios

    OpenAIRE

    Kappel, Erik; Stefaniak, Daniel; Hühne, Christian

    2014-01-01

    Undesired process-induced distortions (PID) are an inherent issue in today's CFRP manufacturing scenarios. Distortions are inevitable due to an interaction of composite-specific and process-specific parameters. In academia it is distinguished in three main phenomena Spring-in, Warpage and Forced- interaction while their specific relevance depends on the part shape at hand. As process distortions remain widely unconsidered in current partdevelopment chains, they induce considera...

  16. Studying Culicoides vectors of BTV in the post-genomic era: resources, bottlenecks to progress and future directions

    Science.gov (United States)

    Culicoides biting midges (Diptera: Ceratopogonidae) are a major vector group responsible for the biological transmission of a wide variety of globally significant arboviruses, including bluetongue virus (BTV). In this review we examine current biological resources for the study of this genus, with a...

  17. From the knowledge acquisition bottleneck to the knowledge acquisition overflow: A brief French history of knowledge acquisition

    OpenAIRE

    Aussenac-Gilles, Nathalie; Gandon, Fabien

    2013-01-01

    International audience This article is an account of the evolution of the French-speaking research community on knowledge acquisition and knowledge modelling echoing the complex and cross-disciplinary trajectory of the field. In particular, it reports the most significant steps in the parallel evolution of the web and the knowledge acquisition paradigm, which finally converged with the project of a semantic web. As a consequence of the huge amount of available data in the web, a paradigm s...

  18. Bridges and bottlenecks: Andrei Sher’s role in the development of international collaboration in Beringian science

    Science.gov (United States)

    Elias, Scott; Dodds, Klaus

    2011-08-01

    Andrei Sher played a leading role in the development of international cooperation and exchange of ideas in Beringian science. The Cold War created great tensions between the USSR and the NATO countries, as the Bering Strait region became one of the front lines of potential military conflict. However, through the persistent efforts of such people as Andrei Sher in Russia and David Hopkins in the USA, scientists were able to overcome political obstacles to attend international Beringian conferences, visit each other's militarized zones to do fieldwork, and collaborate on joint projects.

  19. Incorporation of public hospitals: a "silver bullet" against overcapacity, managerial bottlenecks and resource constraints? Case studies from Austria and Estonia.

    Science.gov (United States)

    Fidler, Armin H; Haslinger, Reinhard R; Hofmarcher, Maria M; Jesse, Maris; Palu, Toomas

    2007-05-01

    This paper presents a new approach for incorporating public hospitals by contrasting the experience from an "old" EU country (Austria) with a new EU member state (Estonia). In the EU (including the new member states) hospital overcapacity is a serious problem, from a technical, fiscal and political perspective. Few countries have succeeded in establishing an appropriate framework for resource management and for guaranteeing long-term financial viability of their hospital network. Many countries are in search of effective policies for improved hospital management and more cost-effective resource use in the health sector. Over the past decade, experiences in Austria and Estonia have emerged as innovative examples which may provide lessons for other EU countries and beyond. This paper describes the evolution of public hospitals from public budgetary units and public management to incorporated autonomous organizations under private corporate law, resulting in a contractual relationship between (public) owners and private hospital management. Outdated and inefficient public sector structures were replaced by more agile corporate management. The arrangement allows for investments, operating costs and budgeting according to strategic business goals as opposed to political "fiat". Shielding hospitals from local political influence is an important aspect of this concept. Horizontal integration through networking of public hospitals and introducing private management helps create a new corporate culture, allowing for more flexibility to achieve efficiencies through downsizing and economies of scale. Based on contracts the new balance between ownership and managerial functions create strong incentives for a more business-like, results-oriented and consumer-friendly management. This was achieved both in Austria and Estonia in a politically sensitive way, adopting a long-term vision and by protecting the interests of hospital owners and staff.

  20. Long orbital period pre-polars containing an early K-type donor stars. Bottleneck accretion mechanism in action

    CERN Document Server

    Tovmassian, G; Zharikov, S; Reichart, D E; Haislip, J B; Ivarsen, K M; LaCluyze, A P; Moore, J P; Miroshnichenko, A S

    2016-01-01

    We studied two objects identified as a Cataclysmic Variables (CVs) with periods exceeding the natural boundary for Roche lobe filling ZAMS secondary stars. We present observational results for V1082 Sgr with 20.82 h orbital period, an object that shows low luminosity state, when its flux is totally dominated by a chromospherically active K- star with no signs of ongoing accretion. Frequent accretion shut-offs, together with characteristics of emission lines in a high state, indicate that this binary system is probably detached and the accretion of matter on the magnetic white dwarf takes place through stellar wind from the active donor star via coupled magnetic fields. Its observational characteristics are surprisingly similar to V479 And, a 14.5 h binary system. They both have early K-type stars as a donor star. We argue, that similar to the shorter period pre-polars containing M-dwarfs, these are detached binaries with strong magnetic components. Their magnetic fields are coupled, allowing enhanced stellar ...

  1. Marine neurotoxins: state of the art, bottlenecks, and perspectives for mode of action based methods of detection in seafood.

    Science.gov (United States)

    Nicolas, Jonathan; Hendriksen, Peter J M; Gerssen, Arjen; Bovee, Toine F H; Rietjens, Ivonne M C M

    2014-01-01

    Marine biotoxins can accumulate in fish and shellfish, representing a possible threat for consumers. Many marine biotoxins affect neuronal function essentially through their interaction with ion channels or receptors, leading to different symptoms including paralysis and even death. The detection of marine biotoxins in seafood products is therefore a priority. Official methods for control are often still using in vivo assays, such as the mouse bioassay. This test is considered unethical and the development of alternative assays is urgently required. Chemical analyses as well as in vitro assays have been developed to detect marine biotoxins in seafood. However, most of the current in vitro alternatives to animal testing present disadvantages: low throughput and lack of sensitivity resulting in a high number of false-negative results. Thus, there is an urgent need for the development of new in vitro tests that would allow the detection of marine biotoxins in seafood products at a low cost, with high throughput combined with high sensitivity, reproducibility, and predictivity. Mode of action based in vitro bioassays may provide tools that fulfil these requirements. This review covers the current state of the art of such mode of action based alternative assays to detect neurotoxic marine biotoxins in seafood.

  2. A microwave detection way by electromagnetic and elastic resonance: Breaking the bottleneck of spatial resolution in microwave imaging

    Science.gov (United States)

    Ji, Zhong; Lou, Cunguang; Shi, Yujiao; Ding, Wenzheng; Yang, Sihua; Xing, Da

    2015-10-01

    The spatial resolution of microwave imaging depends on the geometrical size of the detector. The existing techniques mainly focus on optimizing the antenna design to achieve high detection sensitivity. However, since the optimal antenna size is closely related to the wavelength to be measured, and the miniaturization of the geometrical size is challenging, this limits the spatial resolution of microwave imaging. In this letter, a microwave detection technique based on the electromagnetic-elastic resonance effect is proposed. The piezoelectric materials can produce mechanical responses under microwave excitation, and the amplitude of the microwave can be detected by measuring these responses. In contrast to conventional microwave detection method, the proposed method has distinct advantages in terms of high sensitivity and wide spectral response. Most importantly, it overcomes the limitation of detector size, thus, significantly improving the detection resolution. Therefore, the proposed method has potential for microwave imaging in biomedical applications.

  3. The Jaramillo Bottleneck for Migration of Hominins with Megaherbivores Into Europe via the Danube-Po Gateway

    Science.gov (United States)

    Muttoni, G.; Kent, D. V.; Scardia, G.

    2015-12-01

    Based on ongoing magnetostratigraphic work and updated critical reviews of sites bearing hominin remains and/or tools from greater Europe, including the Balkans and Greece, we maintain that the only compelling evidence of hominin presence in these regions was after the Jaramillo subchron (0.99 Ma), at about the time of the climatic late Early Pleistocene revolution (EPR) and the onset of enhanced glacial/interglacial activity from MIS 22 onward. Europe may have become initially populated during the EPR when, possibly for the first time in the Pleistocene, vast and exploitable ecosystems were generated along the Danube-Po Gateway in the Balkan peninsula and northern Italy. These newly formed settings, characterized by low-lands with open grasslands and reduced woody cover during glacial/interglacial transitions, represented the closest analogues to the savanna environment to which several large mammals linked with hominins in a common food web were adapted and could use as a migratory corridor. We acknowledge that lack of evidence may not be a compelling argument, but the absence of the Jaramillo and out-of-sequence cosmogenic nuclide dates with wide error margins in key sections preclude the use of such evidence to substantiate the presence of humans (and presumably associated biostratigraphic markers) prior to the Jaramillo, and thus logically deny applying such conclusions to other systems.

  4. Overcoming bottlenecks of enzymatic biofuel cell cathodes: crude fungal culture supernatant can help to extend lifetime and reduce cost.

    Science.gov (United States)

    Sané, Sabine; Jolivalt, Claude; Mittler, Gerhard; Nielsen, Peter J; Rubenwolf, Stefanie; Zengerle, Roland; Kerzenmacher, Sven

    2013-07-01

    Enzymatic biofuel cells (BFCs) show great potential for the direct conversion of biochemically stored energy from renewable biomass resources into electricity. However, enzyme purification is time-consuming and expensive. Furthermore, the long-term use of enzymatic BFCs is hindered by enzyme degradation, which limits their lifetime to only a few weeks. We show, for the first time, that crude culture supernatant from enzyme-secreting microorganisms (Trametes versicolor) can be used without further treatment to supply the enzyme laccase to the cathode of a mediatorless BFC. Polarization curves show that there is no significant difference in the cathode performance when using crude supernatant that contains laccase compared to purified laccase in culture medium or buffer solution. Furthermore, we demonstrate that the oxygen reduction activity of this enzymatic cathode can be sustained over a period of at least 120 days by periodic resupply of crude culture supernatant. This is more than five times longer than control cathodes without the resupply of culture supernatant. During the operation period of 120 days, no progressive loss of potential is observed, which suggests that significantly longer lifetimes than shown in this work may be possible. Our results demonstrate the possibility to establish simple, cost efficient, and mediatorless enzymatic BFC cathodes that do not require expensive enzyme purification procedures. Furthermore, they show the feasibility of an enzymatic BFC with an extended lifetime, in which self-replicating microorganisms provide the electrode with catalytically active enzymes in a continuous or periodic manner.

  5. 民营企业成长中的三大瓶颈%The Three Bottlenecks for Private Enterprises' Development

    Institute of Scientific and Technical Information of China (English)

    周鹏; 任俊正

    2009-01-01

    民营企业成长过程中会受到嵌入反应所形成的市场瓶颈、非契合管理所形成的成本瓶颈以及忽视法人治理建设所形成的治理瓶颈三大瓶颈的制约.民营企业突破三大瓶颈关键在于把握创业激情与战略理性之间的平衡、经验管理与制度管理之间的平衡、治理机制与企业发展之间的平衡.

  6. Why do organizations not learn from incidents? Bottlenecks, causes and conditions for a failure to effectively learn

    NARCIS (Netherlands)

    Drupsteen, L.; Hasle, P.

    2014-01-01

    If organizations would be able to learn more effectively from incidents that occurred in the past, future incidents and consequential injury or damage can be prevented. To improve learning from incidents, this study aimed to identify limiting factors, i.e. the causes of the failure to effectively le

  7. Fungal host specificity is not a bottleneck for the germination of Pyroleae species (Ericaceae) in a Bavarian forest.

    Science.gov (United States)

    Hynson, Nicole A; Weiß, Michael; Preiss, Katja; Gebauer, Gerhard; Treseder, Kathleen K

    2013-03-01

    Plants that produce dust seeds can recruit fungi to meet their earliest requirements for carbon and other nutrients. This germination strategy, termed initial mycoheterotrophy, has been well investigated among the orchid family, but there are numerous other plant lineages that have independently evolved mycoheterotrophic germination strategies. One of these lineages is the tribe Pyroleae (Ericaceae). While the fungi associated with mature plants in Pyroleae have been fairly well documented, their mycobionts at the germination and seedling stages are largely unknown. Here, we use an in situ seed baiting experiment along with molecular fingerprinting techniques and phylogenetic tests to identify the fungi associated with seedlings of two Pyroleae species, Pyrola chlorantha and Orthilia secunda. Our results indicate that similar to adult plants, Pyroleae seedlings can associate with a suite of ectomycorrhizal fungi. Some seedlings harboured single mycobionts, while others may have been inhabited by multiple fungi. The dominant seedling mycobiont of both Pyroleae species was a fungus of unknown trophic status in the order Sebacinales. This taxon was also the only one shared among seedlings of both investigated Pyroleae species. We discuss these results juxtaposed to orchids and one additional Pyrola species in the context of ontogenetic shifts in fungal host specificity for mycoheterotrophic nutrition.

  8. Armchair-edged nanoribbon as a bottleneck to electronic total transmission through a topologically nontrivial graphene nanojunction.

    Science.gov (United States)

    Jiang, Liwei; Liu, Zhe; Zhao, Xudong; Zheng, Yisong

    2016-03-01

    It is currently a promising approach to experimentally realize the topological insulator phase transition of graphene by introducing the extrinsic spin-orbit coupling (SOC). Then, electronic total transmission through various topological nontrivial graphene nanojunctions (GNJs) is obtainable, if the electronic transport is supported by the helical edge states. Though the bulk graphene is a gapless semiconductor, the inter-valley scattering could introduce a topological trivial gap in semiconducting armchair-edged graphene nanoribbon (GNR). The SOC should be strong enough to reopen a topological nontrivial gap before close such a trivial gap. Therefore, our theoretical study indicates that a semiconducting armchair-edged graphene nanoribbon (GNR) can not develop the helical edge states when the SOC strength is lower than a threshold, though the bulk phase is topological nontrivial. This implies a competition between the SOC and the inter-valley scattering. However, for a metallic armchair-edged GNR, a small SOC can always open a nontrivial gap. Nevertheless, the helical edge state is much less localized than that in a zigzag-edged GNR of the same width. As a result, and by numerically calculating the electronic transmission spectrum of step- and L-shaped GNJs, we conclude that when an armchair-edged GNR is a part of a GNJ, it is the weak point to realize the electronic total transmission even though the bulk phase of graphene is topologically insulating.

  9. Identifying bottlenecks in transient and stable production of recombinant monoclonal-antibody sequence variants in Chinese hamster ovary cells

    OpenAIRE

    Mason, Megan; Sweeney, Bernadette; Cain, Katharine; Stephens, Paul; Sharfstein, Susan T.

    2012-01-01

    The increasing demand for antibody-based therapeutics has emphasized the need for technologies to improve recombinant antibody titers from mammalian cell lines. Moreover, as antibody therapeutics address an increasing spectrum of indications, interest has increased in antibody engineering to improve affinity and biological activity. However, the cellular mechanisms that dictate expression and the relationships between antibody sequence and expression level remain poorly understood. Fundamenta...

  10. Bottlenecks in domestic animal populations can facilitate the emergence of Trypanosoma cruzi, the aetiological agent of Chagas disease

    Science.gov (United States)

    Levy, Michael Z.; Tustin, Aaron; Castillo-Neyra, Ricardo; Mabud, Tarub S.; Levy, Katelyn; Barbu, Corentin M.; Quispe-Machaca, Victor R.; Ancca-Juarez, Jenny; Borrini-Mayori, Katty; Naquira-Velarde, Cesar; Ostfeld, Richard S.

    2015-01-01

    Faeces-mediated transmission of Trypanosoma cruzi (the aetiological agent of Chagas disease) by triatomine insects is extremely inefficient. Still, the parasite emerges frequently, and has infected millions of people and domestic animals. We synthesize here the results of field and laboratory studies of T. cruzi transmission conducted in and around Arequipa, Peru. We document the repeated occurrence of large colonies of triatomine bugs (more than 1000) with very high infection prevalence (more than 85%). By inoculating guinea pigs, an important reservoir of T. cruzi in Peru, and feeding triatomine bugs on them weekly, we demonstrate that, while most animals quickly control parasitaemia, a subset of animals remains highly infectious to vectors for many months. However, we argue that the presence of these persistently infectious hosts is insufficient to explain the observed prevalence of T. cruzi in vector colonies. We posit that seasonal rains, leading to a fluctuation in the price of guinea pig food (alfalfa), leading to annual guinea pig roasts, leading to a concentration of vectors on a small subpopulation of animals maintained for reproduction, can propel T. cruzi through vector colonies and create a considerable force of infection for a pathogen whose transmission might otherwise fizzle out. PMID:26085582

  11. Why do organizations not learn from incidents? Bottlenecks, causes and conditions for a failure to effectively learn

    DEFF Research Database (Denmark)

    Drupsteen, Linda; Hasle, Peter

    2014-01-01

    If organizations would be able to learn more effectively from incidents that occurred in the past, futureincidents and consequential injury or damage can be prevented. To improve learning from incidents,this study aimed to identify limiting factors, i.e. the causes of the failure to effectively...... by the participants in thisstudy, were tightly related to the learning process, but some indirect causes – or conditions – such aslack of ownership and limitations in expertise were also mentioned.The results illustrate that there are two types of causes for the failure to effectively learn: direct causesand indirect...

  12. Travelling on a budget : predictions and ecological evidence for bottlenecks in the annual cycle of long-distance migrants

    NARCIS (Netherlands)

    Buehler, Deborah M.; Piersma, Theunis

    2008-01-01

    Long-distance migration, and the study of the migrants who undertake these journeys, has fascinated generations of biologists. However, many aspects of the annual cycles of these migrants remain a mystery as do many of the driving forces behind the evolution and maintenance of the migrations themsel

  13. Marine neurotoxins: State of the art, bottlenecks, and perspectives for mode of action based methods of detection in seafood

    NARCIS (Netherlands)

    Nicolas, J.; Hendriksen, P.J.M.; Gerssen, A.; Bovee, T.F.H.; Rietjens, I.M.C.M.

    2014-01-01

    Marine biotoxins can accumulate in fish and shellfish, representing a possible threat for consumers. Many marine biotoxins affect neuronal function essentially through their interaction with ion channels or receptors, leading to different symptoms including paralysis and even death. The detection of

  14. Identifying bottlenecks in charging infrastructure of plug-in hybrid electric vehicles through agent-based traffic simulation

    OpenAIRE

    Lindgren, Juuso; Lund, Peter D.

    2015-01-01

    The effect of different charging infrastructure configurations on the electric-driven distance of plug-in hybrid electric vehicles (e-mileage) has been investigated, using an agent-based traffic simulation. Our findings suggest that the same e-mileage can be achieved with fewer charging poles if the poles support charging from several parking slots around them, and the charging cable is switched from one vehicle to the next. We also find that the charging power supported by most Finnish charg...

  15. Coupled-Cluster Theory Employing Approximate Integrals: An Approach to Avoid the Input/Output and Storage Bottlenecks

    Science.gov (United States)

    Rendell, Alistair P.; Lee, Timothy J.

    1994-01-01

    By representing orbital products in an expansion basis, certain classes of two-electron integrals are approximated for use in CCSD(T) calculations (singles and doubles coupled-cluster plus a perturbational estimate of the effects of connected triple excitations). This leads to a very large reduction in disk storage and input/output requirements, with usually only a modest increase in computational effort. The new procedure will allow very large CCSD(T) calculations to be undertaken, limited only by available processor time. Using the molecular basis as the expansion basis, explicit numerical comparisons of equilibrium geometries, harmonic frequencies, and energy differences indicate that the error due to the use of approximate integrals is less than the error associated with truncation of the molecular basis set.

  16. Insertional mutagenesis and deep profiling reveals gene hierarchies and a Myc/p53-dependent bottleneck in lymphomagenesis.

    Directory of Open Access Journals (Sweden)

    Camille A Huser

    2014-02-01

    Full Text Available Retroviral insertional mutagenesis (RIM is a powerful tool for cancer genomics that was combined in this study with deep sequencing (RIM/DS to facilitate a comprehensive analysis of lymphoma progression. Transgenic mice expressing two potent collaborating oncogenes in the germ line (CD2-MYC, -Runx2 develop rapid onset tumours that can be accelerated and rendered polyclonal by neonatal Moloney murine leukaemia virus (MoMLV infection. RIM/DS analysis of 28 polyclonal lymphomas identified 771 common insertion sites (CISs defining a 'progression network' that encompassed a remarkably large fraction of known MoMLV target genes, with further strong indications of oncogenic selection above the background of MoMLV integration preference. Progression driven by RIM was characterised as a Darwinian process of clonal competition engaging proliferation control networks downstream of cytokine and T-cell receptor signalling. Enhancer mode activation accounted for the most efficiently selected CIS target genes, including Ccr7 as the most prominent of a set of chemokine receptors driving paracrine growth stimulation and lymphoma dissemination. Another large target gene subset including candidate tumour suppressors was disrupted by intragenic insertions. A second RIM/DS screen comparing lymphomas of wild-type and parental transgenics showed that CD2-MYC tumours are virtually dependent on activation of Runx family genes in strong preference to other potent Myc collaborating genes (Gfi1, Notch1. Ikzf1 was identified as a novel collaborating gene for Runx2 and illustrated the interface between integration preference and oncogenic selection. Lymphoma target genes for MoMLV can be classified into (a a small set of master regulators that confer self-renewal; overcoming p53 and other failsafe pathways and (b a large group of progression genes that control autonomous proliferation in transformed cells. These findings provide insights into retroviral biology, human cancer genetics and the safety of vector-mediated gene therapy.

  17. Insertional Mutagenesis and Deep Profiling Reveals Gene Hierarchies and a Myc/p53-Dependent Bottleneck in Lymphomagenesis

    NARCIS (Netherlands)

    Huser, C.A.; Gilroy, K.L.; De Ridder, J.; Kilbey, A.; Borland, G.; Mackay, N.; Jenkins, A.; Bell, M.; Herzyk, P.; Van der Weyden, L.; et al.

    2014-01-01

    Retroviral insertional mutagenesis (RIM) is a powerful tool for cancer genomics that was combined in this study with deep sequencing (RIM/DS) to facilitate a comprehensive analysis of lymphoma progression. Transgenic mice expressing two potent collaborating oncogenes in the germ line (CD2-MYC, -Runx

  18. 韶关市职业教育的瓶颈及对策探究%The Bottleneck and Countermeasures of Occupational Education in Shaoguan

    Institute of Scientific and Technical Information of China (English)

    王剑兰; 张成林

    2015-01-01

    According to the results of the survey ,the Shaoguan occupational education has achieved remark-able results,but there are needed to solve the problem,such as the free tuition policy,the treatment of teachers is low,the employment problem of graduates of foreign. In order to promote the sustainable development of Shaoguan occupational education,it should actively strive for superior departments to support, tuition assistance policy and expenditure per student funding standards free as soon as possible;the integration of resources ,the quantity and scale of the scientific definition of vocational schools.%调查结果显示,韶关市职业教育取得了显著的成效,但同时存在亟需解决问题,如免学费政策、教师待遇偏低、毕业生外地就业等问题。为促进韶关市职业教育可持续发展,应积极争取上级主管部门的支持;尽快制定本市的免学费补助政策和生均经费拨款标准;整合资源,科学厘定职校的数量和规模。

  19. The Bottleneck and Solution of Chinese Folk Sports Culture Development%我国民俗体育文化发展瓶颈与解决策略

    Institute of Scientific and Technical Information of China (English)

    何丽琴

    2014-01-01

    Sports is one of the traditional project activities in China for thousands of years , its historical position and function are very important .The folk sports culture in sports , its development status is not optimistic .A lot of people without a conscious of protecting and inheriting the attitude to the sports culture , together with the relevant laws and regulations on state is not perfect , caused by a considerable impact on the development of these cultural . Many business Companies take folk sports culture to increase their business economic benefits of gimmicks , only pay attention to the value of economy , ignoring its cultural value and cultural value .To solve these problems , we must formulate relevant policies to protect the folk sports culture .%体育运动是我国几千年来的传统活动项目之一,其历史地位和作用都非常重要。而对于体育中的民俗体育文化来讲,其发展现状不容乐观。很多民众对于这种体育文化没有一种自觉的保护和传承的态度,再加上国家的相关法律法规也不完善,导致了这些文化的发展受到了相当大的影响。很多的商业公司将民俗的体育文化作为增加自己商业经济效益的噱头,只注重挖掘其经济方面的价值,忽视了其文化方面的价值以及人文方面的价值。针对这些问题,我们必须制定相关的政策来保护民俗体育文化。

  20. Legal concepts to eliminate the bottleneck in energy-saving modernisations for existing buildings; Rechtskonzepte zur Beseitigung des Staus energetischer Sanierungen im Gebaeudebestand

    Energy Technology Data Exchange (ETDEWEB)

    Klinski, Stefan [Hochschule fuer Wirtschaft und Recht (HWR), Berlin (Germany)

    2009-10-15

    The research project looked at the following: 1. Whether and to what extent the German tenancy law creates, on the one hand, adequate incentives for energy-saving modernisations of existing buildings, on the one hand, and, on the other, whether it creates legal obstacles. 2. How these obstacles could be eliminated i.e. by changing existing tenancy law and instead creating stimuli for energy-saving modernization of existing rental buildings. The report contents a number of specific recommendations for an energy-related reform of the German tenancy law. Major recommendations are: - to eliminate the current toleration duty for modernisation measures if changes are made to the building that conflict with the duties arising from the energy saving provisions of public law, - to consider energy-saving characteristics in the reference rent customary in the locality, - to create a possibility for imposing a flat-rate surcharge which is linked to the savings in heating costs for energy-saving improvement. (orig.)

  1. Divided infraorbital foramen in the lion (Panthera leo): its implications for colonisation history, population bottlenecks, and conservation of the Asian lion (P. l. persica)

    NARCIS (Netherlands)

    Yamaguchi, N.; Kitchener, A.C.; Driscoll, C.A.; Macdonald, D.W.

    2009-01-01

    A divided infraorbital foramen is an important morphological feature in lion taxonomy and has previously been considered to occur only in the Asian lion, Panthera leo persica. Based on an examination of 498 lion skulls from museum collections in Europe and southern Africa, we report for the first ti

  2. Analysis of the Bottleneck of SME Financing and Countermeasures%中小企业融资瓶颈及对策分析

    Institute of Scientific and Technical Information of China (English)

    周艳

    2011-01-01

    SME financing is a world-class problem,so our government should reform the credit, at the same time the SMEs should optimize the financing environment for SMEs, improve credit rating, and broaden financing channels to raise more funds for construction.%中小企业融资难是世界级难题,为此我国政府应该力求信贷改革;同时中小企业也要优化融资环境,提高信用等级,拓宽融资渠道募集更多的资金.

  3. Extracellular Electron Transfer Is a Bottleneck in the Microbiologically Influenced Corrosion of C1018 Carbon Steel by the Biofilm of Sulfate-Reducing Bacterium Desulfovibrio vulgaris.

    Directory of Open Access Journals (Sweden)

    Huabing Li

    Full Text Available Carbon steels are widely used in the oil and gas industry from downhole tubing to transport trunk lines. Microbes form biofilms, some of which cause the so-called microbiologically influenced corrosion (MIC of carbon steels. MIC by sulfate reducing bacteria (SRB is often a leading cause in MIC failures. Electrogenic SRB sessile cells harvest extracellular electrons from elemental iron oxidation for energy production in their metabolism. A previous study suggested that electron mediators riboflavin and flavin adenine dinucleotide (FAD both accelerated the MIC of 304 stainless steel by the Desulfovibrio vulgaris biofilm that is a corrosive SRB biofilm. Compared with stainless steels, carbon steels are usually far more prone to SRB attacks because SRB biofilms form much denser biofilms on carbon steel surfaces with a sessile cell density that is two orders of magnitude higher. In this work, C1018 carbon steel coupons were used in tests of MIC by D. vulgaris with and without an electron mediator. Experimental weight loss and pit depth data conclusively confirmed that both riboflavin and FAD were able to accelerate D. vulgaris attack against the carbon steel considerably. It has important implications in MIC failure analysis and MIC mitigation in the oil and gas industry.

  4. Paradigm shift in transport legislation or rather at the 'bottleneck'; Paradigmenwechsel im Befoerderungsrecht oder am 'Flaschenhals'

    Energy Technology Data Exchange (ETDEWEB)

    Naeser, Hanns [GNS Gesellschaft fuer Nuklear-Service mbH, Essen (Germany)

    2015-01-15

    In the year just started significant decisions with considerable consequences by the Federal Constitutional Court and the Federal Administrative Court in the field of nuclear law are expected. Especially the decision with regards to 'nuclear phase-out' within the 13th amendment of the Atomic Energy Act is being eagerly expected, as with its far-reaching consequences also fundamental constitutional questions need to be answered. The Federal Administrative Court will need to decide on the question, whether she admits the appeal against the Brunsbuettel decision by the Higher Administrative Court Schleswig-Holstein (HAC), which from the view of claimant shifted the fundamental basis of demarcation of responsibilities between the executive and judiciary power. In comparison to these fundamental decisions the awaited decision by the HAC on nuclear transport legislation seems of subordinate importance, although she will proceed with a paradigm shift in the legal area. The decision deals with the question as to whether and when a right of action from a third party within the nuclear transport legislation can be accepted or more precisely under which preconditions a third party has clear standing against a nuclear transport authorisation. As the site selection law (issued on 23 July 2013 BGBI I p. 2552) excludes the recirculation of vitrified waste block canisters from reprocessing spent fuel elements to the transport cask storage facility Gorleben, the decision by the HAC Lueneburg for this site will only be relevant for present unpredictable transportations from the transport cask storage facility Gorleben to a final repository. If necessary interest to seek a declaratory judgment for declaratory action, in concreto danger of recurrence will be approved, is another matter.

  5. System Inadequacy: Bottleneck of the Development of Chinese Librarianship%制度缺位:中国图书馆事业发展的瓶颈

    Institute of Scientific and Technical Information of China (English)

    蒋永福

    2006-01-01

    图书馆立法缺位、职业自律制度缺位、职业权益保障制度缺位和职业准入制度缺位,是阻碍中国图书馆事业发展的瓶颈.制度缺位必然带来职责的缺位和功能的缺位.

  6. Breaking the Land Bottlenecks in the Economy Development%破解园区经济发展中的土地瓶颈

    Institute of Scientific and Technical Information of China (English)

    岳传明

    2014-01-01

    为更好地为园区经济发展提供国土资源服务、保障园区经济发展,本文对国土资源管理工作中遇到的影响园区经济发展的理论困惑和实践难题进行了分析,破解了园区经济发展中的土地瓶颈,提出了相应的建议和对策。%In order to bet er provide land and resources serv-ices of economic development, guarantee the park economic development zone. This article analyzes the influence of land and resources management in the park theoretical confusion and practical problems of economic development, and break-ing zone land bot lenecks in the economy development, puts forward the corresponding suggestions and countermeasures.

  7. 瓶颈网络TCP/主动队列管理模型及仿真%TCP/Active Queue Management Model and Simulation for Bottleneck Networks

    Institute of Scientific and Technical Information of China (English)

    曹振臻; 肖扬; 迟彩霞

    2009-01-01

    提出了一种基于离散时间Markov链的时延闭环反馈TCP/AQM(Active Queue Management)模型,并得到其稳态分布.通过以环路时延为单位,将系统时间分割成长度不同的时隙,分析每个时隙内TCP发送端发送窗口模型和瓶颈路由器队列模型.通过结合相邻时隙的参数,提出了TCP/AQM整体分析模型.该模型可以估计路由器的队列平均长度和丢包率、TCP发送端的平均发送窗口值,因此可以用于分析AQM算法性能以及给新算法的设计提供理论支持.通过在Matlab实施该模型与NS2仿真结果作比较,证实了该模型在模拟时延闭环反馈的TCP/RED系统的有效性.

  8. 真空玻璃生产瓶颈的思考%Thinking of "bottle-neck" in Production of Vacuum Glass

    Institute of Scientific and Technical Information of China (English)

    林一丁

    2015-01-01

    真空玻璃生产遭遇的瓶颈主要是支撑点、封边技术和封边用低熔点玻璃,文章对真空玻璃的发展进行了简要阐述,对生产制造过程中遇到的瓶颈问题进行了分析,提出了解决办法和途径.

  9. Bottle-neck Relief of Bus Speed using FPGA Platform%利用FPGA平台解决接口的总线速度瓶颈

    Institute of Scientific and Technical Information of China (English)

    高兴军

    2005-01-01

    通过使用Sigma Design公司的EM8560嵌入式数字图像处理器及Altera FPGA与Lattice CPLD,解决处理器外部总线接口速度对系统性能的限制问题;从系统组成、系统工作原理和实现方法以及改进后的系统性能分析三部分来说明.

  10. Bottle-necks for restoration of the eel population, Anguilla anguilla (L.) of the river Yser basin (Flanders)

    OpenAIRE

    Denayer, B.; Belpaire, C.

    1996-01-01

    This paper describes some preliminary results on the status of eel populations in the river Yser and its tributaries. Data on glass eel migration at the river mouth during recent years are presented and compared with earlier observations. Populations of yellow eel were studied at several localities during 3 successive periods. Attention was given to all factors limiting development of normal eel stocks, especially migration obstruction to all stages. Suggestions for improving the aquatic habi...

  11. The Moulds Industry is A Bottle-Neck of Chinese Manufacturing Industry%模具:中国制造业的瓶颈

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ 本刊据机经网消息,模具生产技术水平的高低不仅是衡量一个国家产品制造水平高低的重要标志,而且在很大程度上决定着这个国家产品质量、效益及新产品开发能力,而我国模具业的低水平问题早已是公认的事实.我国目前的模具开发制造水平比国际先进水平至少相差10年.

  12. 长江天字一号卡口拓宽整治%Renovating of Widening Yihao Bottle-neck Reach of Yangtze River

    Institute of Scientific and Technical Information of China (English)

    何会清

    2007-01-01

    长江湖南天字一号卡口存在影响泄洪、航运,对集成垸及上车弯新河已护工程冲刷,影响岸坡稳定等问题.文章通过设计进行方案比较,对卡口进行拓宽采用分年度实施的办法,取得较好的经济效益.

  13. On the bottle-neck which obstructs stable development of an enterprise%谈阻碍企业持续发展的“瓶颈”

    Institute of Scientific and Technical Information of China (English)

    付志中

    2002-01-01

    对企业来说,创业的成功并不能保证企业实现持续的发展和持续的成功。本文认为,企业成长存在诸多“瓶颈”:经验化的思维模式,多元化的盲目扩张,保守化的企业经营,形式化的管理控制等等。企业必须建立创新的、开放的、科学的、高效的经营理念,才能保持企业的稳定成长。

  14. WHERE IS THE BOTTLE-NECK OF IP WITH SMES%中小企业信息化瓶颈何在

    Institute of Scientific and Technical Information of China (English)

    刘黄

    2003-01-01

    尽管从2000年开始,全国企业信息化工作领导小组就启动了“企业信息化”工程;尽管2001年,国家经贸委下发了《关于推进中小企业信息化有关工作》的通知,但正如去年年底国务院信息化工作办公室副主任刘鹤所说:“中小企业信息化,是一个全新的命题。”

  15. Globalization as a Driver or Bottleneck for Sustainable Development: Some Empirical, Cross-National Reflections on Basic Issues of International Health Policy and Management

    Directory of Open Access Journals (Sweden)

    Arno Tausch

    2013-01-01

    Full Text Available BackgroundThis article looks at the long-term, structural determinants of environmental and public health performance in the world system. MethodsIn multiple standard ordinary least squares (OLS regression models, we tested the effects of 26 standard predictor variables, including the ‘four freedoms’ of goods, capital, labour and services, on the following indicators of sustainable development and public health: avoiding net trade of ecological footprint global hectare (gha per person; avoiding high carbon emissions per million US dollars GDP; avoiding high CO2 per capita (gha/cap; avoiding high ecological footprint per capita; avoiding becoming victim of natural disasters; a good performance on the Environmental Performance Index (EPI; a good performance on the Happy Life Years (HLYs scale; and a good performance on the Happy Planet Index (HPI. ResultsOur research showed that the apprehensions of quantitative research, critical of neo-liberal globalization, are fully vindicated by the significant negative environmental and public health effects of the foreign savings rate. High foreign savings are indeed a driver of global footprint, and are a blockade against a satisfactory HPI performance. The new international division of labour is one of the prime drivers of high CO2 per capita emissions. Multinational Corporation (MNC penetration, the master variable of most quantitative dependency theories, blocks EPI and several other socially important processes. Worker remittances have a significant positive effect on the HPI, and HLYs. ConclusionWe re-analysed the solid macro-political and macro-sociological evidence on a global scale, published in the world’s leading peer-reviewed social science, ecological and public health journals, which seem to indicate that there are contradictions between unfettered globalization and unconstrained world economic openness and sustainable development and public health development. We suggest that there seems to be a strong interaction between ‘transnational capitalist penetration’ and ‘environmental and public health degradation’. Global policy-making finally should dare to take the globalization-critical organizations of ‘civil society’ seriously. This conclusion not only holds for the countries of the developed “West”, but also, increasingly, for the growing democracy and civil society movements around the globe, in countries as diverse as Brazil, Russia, China, or ever larger parts of the Muslim world.

  16. Population genetic analysis of microsatellite variation of guppies (Poecilia reticulata) in Trinidad and Tobago: evidence for a dynamic source-sink metapopulation structure, founder events and population bottlenecks.

    Science.gov (United States)

    Barson, N J; Cable, J; Van Oosterhout, C

    2009-03-01

    Riverine fish populations are traditionally considered to be highly structured and subject to strong genetic drift. Here, we use microsatellites to analyse the population structure of the guppy (Poecilia reticulata), focussing on the headwater floodplain area of the Caroni drainage in Trinidad. We also analyse the population genetics of guppies in the Northern Drainage in Trinidad, a habitat characterized by rivers flowing directly into the sea, and a small isolated population in Tobago. Upland Caroni populations are highly differentiated and display low levels of genetic diversity. However, we found no evidence to suggest that these upland populations experienced recent population crashes and the populations appear to approach mutation-drift equilibrium. Dominant downstream migration over both short- and long-time frames has a strong impact on the population genetics of lowland Caroni populations. This drainage system could be considered a source-sink metapopulation, with the tributary furthest downstream representing a 'super sink', receiving immigrants from rivers upstream in the drainage. Moreover, the effective population size in the lowlands is surprisingly low in comparison with the apparently large census population sizes.

  17. A recent bottleneck in the warthog and elephant populations of Queen Elizabeth National Park, revealed by a comparative study of four mammalian species in Uganda national parks

    DEFF Research Database (Denmark)

    Muwanika, Vincent B.; Siegismund, Hans Redlef; Okello, John Bosco A.;

    2003-01-01

    Until 1972, Uganda's national parks boasted of large numbers of large mammal species. Following the breakdown of law and order between 1972 and 1985, large-scale poaching led to an unprecedented decline in numbers of most large mammals in Uganda's national parks. However, the extent of decline...... microsatellite loci (for elephant and warthog populations) and mitochondrial control sequence variation in the warthogs, elephants, buffaloes and hippopotamuses. Queen Elizabeth National Park showed extreme reduction in nucleotide diversity for two species, the common warthog (p= 0.0%) and African elephant (p= 0...... varied in the different parks across different animal species. We have investigated the genetic effects of these reductions in four mammalian species (the common warthog, African savannah elephant, savannah buffalo and common river hippopotamus) from the three major parks of Uganda using both...

  18. 民营银行发展的瓶颈及对策%A Brief Analysis of Bottlenecks and Development Model during Early Development of the Private Banks

    Institute of Scientific and Technical Information of China (English)

    刘非; 郑一凡

    2015-01-01

    随着我国金融改革步步深入,顶层框架设计日趋完善,民营银行在优化金融生态,构建公平机制上将发挥不可估量的作用。鉴于目前监管政策和实施细则尚不完善,试点的差异化经营经验仍显不足,其初期的发展将面临资产规模、风控体系、资金保障等瓶颈问题,如何在现有政策框架内,正确寻找自身定位,创新思路应对挑战,以取得长久持续发展非常关键。在现有政策回顾、政策意图分析、初期瓶颈探讨和政府、民营银行的应对措施分析的基础上,完善政策保障,创新金融服务,才能推动民营银行持续健康发展。%As China’s financial reform steps further and top-level design is gradually improved, private bank is able to step on the historical stage which plays an immeasurable role in the optimization of financial ecology and fair mechanism. In the face of the faultiness of policy and regulatory and the inexperience in management, the expansion of private bank will be limited in the scale of assets, risk-control system and follow-up fund. This paper, which can be divided into four aspects, will focus on accurately positioning in current market, innovation of business model and the path of sustainable development in order to make recommendations for the development of private banks. Finally, the paper includes that only we improve the policy guarantee, innovate the financial service could promote private bank continuous and healthy development.

  19. Mental rotation impairs attention shifting and short-term memory encoding: neurophysiological evidence against the response-selection bottleneck model of dual-task performance

    NARCIS (Netherlands)

    M.M. Pannebakker; W.O. van Dam; G.P.H. Band; K.R. Ridderinkhof; B. Hommel

    2011-01-01

    Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial attenti

  20. Face to face:Qiu He,Party secretary of Kunming,Yunnan province on breaking the bottleneck of mindset%对话仇和

    Institute of Scientific and Technical Information of China (English)

    王运宝

    2010-01-01

    @@ 从宿迁到昆明,仇和一路走来,而新闻媒体中的仇和、市民话语中的仇和与真实的仇和等不同影像,在这个过程中相互交织与叠加.自从就任云南省委常委、昆明市委书记,仇和用一种"旋风式"的执政方式搅动起这座"软绵绵"的西南城市.

  1. Mental rotation impairs attention shifting and short-term memory encoding: neurophysiological evidence against the response-selection bottleneck model of dual-task performance.

    Science.gov (United States)

    Pannebakker, Merel M; Jolicœur, Pierre; van Dam, Wessel O; Band, Guido P H; Ridderinkhof, K Richard; Hommel, Bernhard

    2011-09-01

    Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial attention to a second stimulus (S2). Visual-spatial attention was monitored by using the N2pc component of the ERP. In addition, we examined the sustained posterior contralateral negativity (SPCN) believed to index the retention of information in visual short-term memory. We found modulations of both the N2pc and the SPCN, suggesting that engaging mechanisms of mental rotation impairs the deployment of visual-spatial attention and delays the passage of a representation of S2 into visual short-term memory. Both results suggest interactions between mental rotation and visual-spatial attention in capacity-limited processing mechanisms indicating that response selection is not pivotal in dual-task delays and all three processes are likely to share a common resource like executive control.

  2. Breaking the bottleneck: Use of molecular tailoring approach for the estimation of binding energies at MP2/CBS limit for large water clusters

    Science.gov (United States)

    Singh, Gurmeet; Nandi, Apurba; Gadre, Shridhar R.

    2016-03-01

    A pragmatic method based on the molecular tailoring approach (MTA) for estimating the complete basis set (CBS) limit at Møller-Plesset second order perturbation (MP2) theory accurately for large molecular clusters with limited computational resources is developed. It is applied to water clusters, (H2O)n (n = 7, 8, 10, 16, 17, and 25) optimized employing aug-cc-pVDZ (aVDZ) basis-set. Binding energies (BEs) of these clusters are estimated at the MP2/aug-cc-pVNZ (aVNZ) [N = T, Q, and 5 (whenever possible)] levels of theory employing grafted MTA (GMTA) methodology and are found to lie within 0.2 kcal/mol of the corresponding full calculation MP2 BE, wherever available. The results are extrapolated to CBS limit using a three point formula. The GMTA-MP2 calculations are feasible on off-the-shelf hardware and show around 50%-65% saving of computational time. The methodology has a potential for application to molecular clusters containing ˜100 atoms.

  3. 全民医保亟待打破“十不”瓶颈%“Ten No”Bottlenecks Should Be Broken for Achieving Universal Health Care

    Institute of Scientific and Technical Information of China (English)

    田芬

    2014-01-01

    We have basically achieved the goal of universal health care in China. However, it must be clearly realized that there are still problems such as inconsistence in systems, unclear classification in management departments, non-standardized professional criteria for insurance agencies, non-equivalence in right and duty, non-differentiation in social insurance and commercial insurance, unclear definition of “diseases”, unclear limitation in purchasing service, unclear definition in accessing local or offsite health services, unclear risk prediction, imbalance in demands and supplies, inefficiency in combating insurance fraud, unclear definition in taxes and fees. It is also urgent to accelerate the modernization of administrative system and governance capacity.%我国基本实现全民医保,但必须清醒地看到,目前的全民医保存在着制度不统一、管理归属不明确、经办不标化,权利义务不对等,社保商保不分,对“病”的界定不清,购买服务界线不清,本地异地就医不分,风险预测不清,供需不平衡,对欺诈骗保打击不力,税费不分等问题,亟待加快治理体系和治理能力现代化。

  4. 商业银行绿色信贷的瓶颈与应对策略%Bottleneck and Countermeasures of Commercial Bank’s Green Credit

    Institute of Scientific and Technical Information of China (English)

    睢博; 胡杰

    2013-01-01

      自2007年7月我国实施绿色信贷政策以来,商业银行对节能减排项目的支持力度日益增强。但是,商业银行对高耗能企业的贷款却有增无减。文章从风险预期的角度,运用数理分析方法,对商业银行增加高耗能产业贷款的原因进行了探讨,认为商业银行给予高耗能企业贷款源于企业财富门槛和风险门槛,而影响企业财富门槛和风险门槛的主要因素是商业银行对于投资项目成功概率的判定;在长期动态过程中,商业银行对项目成功概率的判定,是基于企业前一期的投资经历。%  Since the policy of the green credit was carried in July of 2007 ,the commercial banks always sup-port the project of energy conservation measures increasingly day by day .However ,the size of the loan for highly energy-consuming companies has been raised continuously .This paper is discussing the cause of the increasing loan for highly energy-consuming companies by the method of mathematical analysis from the perspective of risk expectation .The main reason for this phenomenon is the limitation of wealth threshold and risk threshold ,which are the principal factors to the judgment on the investment projects success ratio of commercial bank .In the long and dynamic process ,the success ratio determined by commercial bank is based on the investment experience in the previous period .

  5. Research on the Reasons of E-commerce Logistics Bottleneck%电子商务中物流瓶颈成因研究

    Institute of Scientific and Technical Information of China (English)

    熊晓艳

    2013-01-01

    The development of electronic commerce has gradually changed the way we work and live, making it more convenient, flexible and comfortable, especially in access to information, information transmission, and all kinds of service activities, payment, shipping method, etc. But because China is a developing country which has entered directly into the information society without experiencing the developed industrial civilization, the development of e-business is faced with severe challenges and tests.%电子商务的发展已经逐步改变了我们的工作和生活方式,使其更加方便、灵活和自如。尤其是在获取信息、传输信息、各种服务活动、付款、送货方式等方面。但由于我国是一个没有经历发达工业文明而直接进入信息社会的发展中国家,电子商务在发展过程中面临着各种严峻的挑战和考验。

  6. Realizing the Now-or-Never bottleneck and Chunk-and-Pass processing with Item-Order-Rank working memories and masking field chunking networks.

    Science.gov (United States)

    Grossberg, Stephen

    2016-01-01

    Christiansen & Chater's (C&C's) key goals for a language system have been realized by neural models for short-term storage of linguistic items in an Item-Order-Rank working memory, which inputs to Masking Fields that rapidly learn to categorize, or chunk, variable-length linguistic sequences, and choose the contextually most predictive list chunks while linguistic inputs are stored in the working memory. PMID:27561607

  7. Corneal replication is an interferon response-independent bottleneck for virulence of herpes simplex virus 1 in the absence of virion host shutoff.

    Science.gov (United States)

    Pasieka, Tracy Jo; Menachery, Vineet D; Rosato, Pamela C; Leib, David A

    2012-07-01

    Herpes simplex viruses lacking the virion host shutoff function (Δvhs) are avirulent and hypersensitive to type I and type II interferon (IFN). In this study, we demonstrate that even in the absence of IFN responses in AG129 (IFN-αβγR(-/-)) mice, Δvhs remains highly attenuated via corneal infection but is fully virulent via intracranial infection. The data demonstrate that the interferon-independent inherent replication defect of Δvhs has a significant impact upon peripheral replication and neuroinvasion.

  8. Yasukuni Shrine--the Bottleneck of Sino-Japanese Relations%靖国神社--中日关系的一个瓶颈

    Institute of Scientific and Technical Information of China (English)

    寇春莹; 魏桦

    2004-01-01

    靖国神社问题已经成为中日关系中的一个非常敏感的政治问题.靖国神社问题的实质,就是日本政府如何认识和对待过去的侵略历史.这既关系到曾经遭受日本军国主义侵略之害的亚洲各国人民的感情的问题,同时也关系到日本这个国家的今后走向.日本政界要员连续参拜靖国神社既有其深刻的历史根源,也与日本九十年代以来的国内政治、经济状况密切相关,同时参拜之举也是政客为迎合国内政治气候的一种政治手腕.进入新世纪,中日两国只有在正视历史的基础上,把历史问题与双方关系的发展联系起来看,坚持"以史为鉴,面向未来"的原则,才能够保证中日关系健康的发展.

  9. Beyond a Mask and Against the Bottleneck: Retroactive Dual-Task Interference During Working Memory Consolidation of a Masked Visual Target

    NARCIS (Netherlands)

    Nieuwenstein, Mark; Wyble, Brad

    2014-01-01

    While studies on visual memory commonly assume that the consolidation of a visual stimulus into working memory is interrupted by a trailing mask, studies on dual-task interference suggest that the consolidation of a stimulus can continue for several hundred milliseconds after a mask. As a result, es

  10. 大学生参与课余体育的瓶颈问题%"Bottleneck" Research on College Students' Participating in Extracurricular Sports

    Institute of Scientific and Technical Information of China (English)

    凌青东

    2012-01-01

    Extracurricular sports are the key ensurance of improving the physical fitness of college students.Based on the subjective cognition and participating degree of college students and starting from the social factors,family factors and school factors which influence students' physique,this paper will study on the reasons of the decline of college students' physical fitness in order to solve the problems.%课余体育是大学生身体素质提高的关键保障.本研究从大学生对课余体育的主观认识和参与程度,以及影响学生体质的社会因素、家庭因素、学校因素等维度出发,探讨大学生身体素质下降的原因,以便"对症下药".

  11. From "Migrant Workers Boom" to "Migrant Workers Scarcity"——Analysis of Institutional Bottleneck of Rural Surplus Labors Transfer in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Through description of three-steps characteristic of dual economic theory and its practical significance to the process of industrialization and urbanization in China,and making comparative analysis between important criterion of "Lewis turning point" and current situation of rural surplus labors market in China,we can find that there exists a great deal of surplus labors in rural areas in our country,improvement of peasant income is the result of external interference of government,and demographic dividend in our country hasn’t finished.These phenomena go against the theory of "Lewis turning point".So it can prove that "Lewis turning point" in China hasn’t come yet.The paper points out the major factors of coexistence of "migrant workers scarcity" and labors redundancy in our country.The first one is structure contradiction of labors market;the second one is law of supply-demand of labors market;the third one is institutional barrier which hinders labors in free flow of census register and social guarantee.Therefore,if we want to realize successful transfer of rural surplus labors and the goal of industrialization and urbanization,we must promote upgrading of industrial structure,change the style of economic growth and realize harmonious development of regional economy in macrocosmic level;And in microcosmic level,we should eliminate institutional barrier which hinders transfer of rural surplus labors.

  12. Removing the taint : bottlenecks and possible directions for a solution in the marketing of the meat of non-castrated male pigs

    NARCIS (Netherlands)

    Klep, L.M.F.

    2008-01-01

    Onderzoeksresultaten laten zien dat het onwaarschijnlijk is dat er een eenvoudige oplossing bestaat voor het stoppen met castratie van beertjes in de varkenshouderij. Er dient gezocht te worden naar een combinatie van verschillende methoden. De berengeurproblematiek is primair een probleem van markt

  13. 社交网站盈利模式与发展探讨%Revenue Model and Development Bottleneck of Social Network Sites

    Institute of Scientific and Technical Information of China (English)

    李广春

    2013-01-01

    Along with the expansion of the user scale in social network site, the business value of social network site be-comes increasingly salient, as a result, how to exploit and use it is of significant important. Although there are some revenue mod-els for social network sites at present, such as advertising, web games, virtual goods sales, the profitability and development di-rection of social network site is not clear. Even worse, the homogeneity of social network site has become seriously as the low threshold of entrance, some loyal users will simply fade away. If the social network site operators have high ambitions to sustain-able development, they must learn how to maintain a good customer relationship and do better customer service network, after-wards they can promote the rational exploitation of user resources, and make the joint of capital market to realize benign circle for development.%  随着社交网站用户规模的扩大,社交网站的商业价值也日渐凸显,对其价值的开发和利用则显得尤为重要。虽然涌现出了如广告、网页游戏、虚拟物品销售等盈利模式的业务,但由于网站对未来的发展不够明朗,盈利效果也并不理想,无法支撑网站的持续发展,同时社交网站领域新加入者增多,网站同质化现象相当严重,网站功能开发无法满足用户不断变化的娱乐需求,用户逐渐消失。社交性质的网站想要获得可持续的长远发展,就必须在维系用户关系、做好网络服务的基础上,将用户关系转化为网站可以开发利用的资源,积极探索稳定可行的盈利模式,并与资本市场进行对接,最终实现良性循环的商业发展。

  14. 我国飞机租赁融资的发展障碍与解决之道%Bottlenecks of Aircraft Lease Financing in China and Potential Measures to Address them

    Institute of Scientific and Technical Information of China (English)

    王振; 彭爽

    2006-01-01

    @@ 中国航空运输业和飞机租赁市场的发展特点 一是中国航空运输业近年来一直保持高速增长的态势.2005年中国民航的旅客运输量创下了有史以来的最高记录,达到了1.38亿人次,货邮运输量306.7万吨,完成运输总周转量261.3亿吨公里.截止到 2005年底,我国定期航班航线达到1200条,其中国内航线(包括香港、澳门航线)975条,国际航线225条,境内民航定期航班通航机场135个(含香港、澳门),形成了以北京、上海、广州机场为中心,以省会、旅游城市机场为枢纽,其他城市机场为支干,联结国内133个城市,国际38个国家80个城市的航空运输网络.

  15. 制造业突破库存管理瓶颈的方法及实证研究%Manufacturing Breakthroughs Inventory Management Bottleneck Method and Empirical Research

    Institute of Scientific and Technical Information of China (English)

    董鹏; 郭丽美

    2013-01-01

    At present through the analysis of domestic manufacturing inventory status and management ideas, to find the United States of America Carlisle companies finished inventory backlog of reason and the backlog of inventory to the production and operation of enterprises brought bad influence. Combined with examples of Calais companies to reduce inventory, points out that the application of management by objectives, fishbone diagram, ABC classification management tool, is the most effective method to reduce the inventory. This succeeded in reducing inventory, related to the manufacturing industry for effective inventory management to provide reference.%  要:通过分析目前国内制造业的库存现状及管理思路,找出美国卡莱公司造成成品库存积压的原因及库存积压给企业生产经营带来的不良影响。结合卡莱公司降低库存的实例,指出运用目标管理、鱼骨图、ABC分类等管理工具,是降低库存的最有效方法。本次成功地降低了库存量,为相关制造业进行有效的库存管理提供借鉴。

  16. 历史文化街区的市政工程技术规范瓶颈与对策%BOTTLENECK AND STRATEGY OF MUNICIPAL ENGINEERING SPECIFICATION IN HISTORIC CONSERVATION AREA

    Institute of Scientific and Technical Information of China (English)

    李新建; 朱光亚

    2012-01-01

    我国历史文化街区缺乏专门的市政工程技术规范,保护规划实践往往因套用现行一般市政工程技术规范而导致偏差.通过分析我国现行市政工程技术规范和标准以“指令性”的具体技术手段和参数为主、适应性和灵活性不足的缺陷,指出历史文化街区应制定适应其物质空间特性和遗产保护要求的专门的“性能化”市政工程技术规范,与一般城市建设标准保持“适度差异”,并提出实现这一目标的法规和管理对策.%In China,historic conservation area has not pertinent technique specification for its municipal engineering, and its conservation is always harmed by mechanical application of existing generic specification of urban construction, which is prescriptive-based and inadaptable to heritage conservation. Municipal engineering in historic conservation area needs special performance-based technique specification, which is allowably different from those generic standards and requires some legislative and administrant measures to put in practice.

  17. Research on the Bottleneck Problem of China’s Cross-Border Electronic Commerce%中国跨境电子商务发展的“痛点”分析

    Institute of Scientific and Technical Information of China (English)

    文瑞

    2015-01-01

    近年来,随着经济全球化和电子商务的快速发展,跨境电子商务成为国际贸易的新方式。相较于传统贸易,中国跨境电子商务交易规模不断扩大,并保持连续性的高速增长,但同时,跨境电子商务也面临着诸如支付、物流、报关、商检、售后等诸多“痛点”。因此,亟需通过建设跨境电子商务产业园区,创新跨境物流服务,发挥跨境创牌优势,培养全面发展型人才,重构跨境电子商务适用规则等措施来推动中国跨境电子商务进一步的发展。%Recently,cross-border e-commerce became the new way of international trade with economic globalization and the rapid development of electronic commerce. Compared with the traditional trade,China’s cross-border e-commerce transactions expand continually and keep the continuous high-speed growth. At the same time,cross-border e-commerce is faced with some pain points such as payment,logistics,customs clearance,commodity inspection and after sales. Therefore, we urgently need to take some measures,like the construction of cross-border e-commerce industrial park,cross-border logistics service innovation,giving full play to the advantages of cross-border brand,cultivating comprehensive talent, refactoring applicable cross-border e-commerce rules,so as to promote the further development of Chinese cross-border electronic commerce.

  18. B2C E-commerce Development Bottleneck-Third-party Logistics and Distribution%B2C电子商务发展瓶颈—第三方物流配送

    Institute of Scientific and Technical Information of China (English)

    韩甘临

    2011-01-01

    The electronic business enterprise logistics strategy is to improve the main logistics distribution quality, best serviceto keep consumers distribution loyalty to as low as possible operation cost to reach a certain customer satisfaction.Logistics distribution is electronic commerce basic component of electronic commerce development is the most weak links.As the electronic commerce development,the logistics of electronic business rote has become more obvious,e-commerce there is a special relationship.With the rapid development in information technology, and logistics development level and electronic commerce development level but also has the very big disparity.At the end of the logistics problems to solve,marks the end of the electroniccommerce flow. Logistics distribution and e-commerce business process of subsequent guarantee%电子商务企业的物流战略主要是提高物流配送质量,以最好地配送服务来维持消费者忠诚度,以尽可能低的企业运营成本来达到一定客户满意程度。物流配送是电子商务基本组成部分,也是电子商务发展最为薄弱环节。随着电子商务发展,物流对电子商务的作用也日益突出,它与电子商务存在着一种特殊关系。随着信息技术地飞速发展,而物流发展水平却与电子商务发展水平还有很大差距。物流问题的最后解决,标志着整个电子商务流程的结束。物流配送又是电子商务中商务流程的后续保证。

  19. From “Migrant Workers Boom†to “Migrant Workers Scarcity†—Analysis of Institutional Bottleneck of Rural Surplus Labors Transfer in China

    OpenAIRE

    Wang, Qin

    2010-01-01

    Through description of three-steps characteristic of dual economic theory and its practical significance to the process of industrialization and urbanization in China, and making comparative analysis between important criterion of "Lewis turning point" and current situation of rural surplus labors market in China, we can find that there exists a great deal of surplus labors in rural areas in our country, improvement of peasant income is the result of external interference of government, and d...

  20. 突破素质瓶颈,加快龙岩市农村妇女劳动力转移%Breaking through the quality bottleneck and speeding up migration of rural women labour force in Longyan

    Institute of Scientific and Technical Information of China (English)

    刘淑兰; 郑逸芳

    2005-01-01

    本文分析了龙岩市农村妇女劳动力转移的基本状况以及素质对妇女劳动力转移就业的制约,强调加强男女平等宣传、农村基础教育、职业教育和就业服务等对于突破素质瓶颈、加快龙岩市农村妇女富余劳动力转移的重要意义.

  1. 浅谈90后中职生德育工程瓶颈及策略%On Moral Education Project Bottlenecks and Strategies of Post-90s Vocational Students

    Institute of Scientific and Technical Information of China (English)

    关晶

    2014-01-01

    随着离婚率的日趋增多,基于离异、重组家庭的问题型中职生比例无可回避地随之攀升。直面90中职生现在的掩贫炫富、两极差异、愤青心理、早恋泛滥、感情转移、不知感恩等德育现状,中职学校惟其以人为本、追根溯源、携手家长、综合纠偏,方为标本兼治之策。%With the divorce rate is increasing, the proportion of problem-based vocational students of divorced, remarried families is also unavoidable to subsequently rise. Based on the moral education situation of now post-90s vocational students that covering poor showing off wealth, poles differences, angry youth psychology, puppy love flooding, emotional transformation and ungrateful, vocational college should adhere to the people-oriented, track the source, work with parents and comprehensive correction to solve these problem.

  2. 基于元胞自动机的高速公路临时瓶颈交通流仿真%Simulation of Temporary Traffic Bottleneck on Highways Based on Cellular Automaton

    Institute of Scientific and Technical Information of China (English)

    江欣国; 夏亮

    2016-01-01

    为研究强制换道及冲突点分布对高速公路临时瓶颈交通流的影响,在NS(NaSch)模型和STCA (symmetric two-lane cellular automata)模型的基础上,引入强制换道规则,根据瓶颈口上游驾驶员心理状态的变化,建立高速公路瓶颈交通流模型.在开口边界条件下,针对不同的安全换道概率、强制换道概率、冲突点距离和冲突区间长度参数,模拟得到瓶颈交通流量和换道频率与车辆到达率的关系.仿真结果表明,安全换道行为对系统流量影响小;强制换道行为是降低瓶颈系统最大流量的主要因素,当安全换道概率为0.5时,强制换道概率从0.0增加至0.1,最大流量下降了17%;冲突点距离的增加缓解了交通拥堵程度,当冲突点距离从1 cell增加至4 cell时,临界车辆到达率上升了4%;冲突区间长度对交通事故风险的影响较大,最大强制换道频率随冲突区间长度的增加而增加.

  3. 民族传统体育高脚马运动发展瓶颈分析%On Bottlenecks of Development of Chinese Minority Traditional Sports Event "Horse on Stilts"

    Institute of Scientific and Technical Information of China (English)

    陈辉

    2012-01-01

    Chinese minority traditional sports event "Horse on Stilts" through a decade of development, the speed isamazing. 100 m and 200 m performance level has been running close to or above the results, but fn the relay rules of project requirements and project settings for a single, always influence and restrict "Horse on Stilts" sports development space. According to previous project of the national democratic movement's "Horse on Stilts" relay performance analysis,combination with Hong he Pl:efecture of Yunnan province athletes run and "horse on stilts" run'to the tests, As welu as in "horse on stilts" project settings on thinking. The current "Horse on Stilts" relay race rules, the project set up research and analysis, attempt to explore the development of "Horse on Stilts" movement favorable factors, and the formation of scientific theory to guide the development of "Horse on Stilts" movement.%民族传统体育高脚马运动在近十年的竞技发展中,其发展速度是惊人的,100米和200米成绩已接近甚至超过了平跑成绩,但接力跑项目的规则要求和项目设置的单一,始终影响和制约着高脚马运动发展的空间,笔者根据历届全国民运会高脚竞速接力项目成绩的分析,并结合云南省红河州高脚竞速运动员平跑与高脚跑的各项测试,以及在高脚马项目设置上的思考,对现有高脚竞速接力跑竞赛规则、项目设置进行研究分析,试图探索出高脚马运动发展的有利因素,并形成科学理论指导高脚马运动的发展。

  4. The Analysis of "Bottleneck" Structural Model on Constructing Ecological Interpersonal Relation inside Enterprises%企业内部生态人际的"瓶状"结构模型剖析

    Institute of Scientific and Technical Information of China (English)

    黄江泉; 蔡根女

    2009-01-01

    结合一些著名学者对影响企业人际关系的因素分析,文章梳理出人际距离等影响企业入际关系发展的七个最基本要素,并深入分析、比较了它们在企业内部人际关系构成中的地位与作用.在此基础上,构造了一个结构形象、层次分明的"瓶状"人际结构模型,为企业建设、发展生态人际提供一定的指导.

  5. An Analysis of Bottleneck and Strategy in Developing Service Outsourcing in China%我国服务外包产业发展中的瓶颈问题及对策分析

    Institute of Scientific and Technical Information of China (English)

    陈冰冰; 刘莹莹

    2011-01-01

    我国服务外包产业在发展的过程中存在的问题,主要表现在各个城市发展服务外包优势不明显;承接的外包项目业务量和项目质量还有待于提高;服务外包企业竞争力需要继续提高,缺少行业组织的引领;缺乏高端的专业人才;知识产权保护意识薄弱、措施不完善等方面。我国应逐渐完善服务外包的相关政策,引导国内有影响力的企业成立相应的行业组织;在国家的政策扶持下,发挥好自身优势,充分利用我国的大量资源,快速增加产业规模,逐步完善基础设施,加强人才建设,提高国内服务外包企业的各项能力,从而承接质量更高、业务量更大的项目。%In developing service outsourcing in China,we encounter a series of difficulties,i.e.advantages in all cities are unclear,the quantity and quality of settling outsourcing business need improving,so is the enterprise competitiveness,lacking of leading trade organization and high-end professionals,and awareness and measure of protecting intellectual property is weak.China should improve related policies to guide influential domestic enterprises to build their trade organization.Supported by national policies,the enterprises take their advantages to expand enterprise scale by using the rich resources,steadily improve infrastructure,talent teams,and abilities of service outsourcing enterprises at home,and take more high-quality and large-quantity projects.

  6. The Bottle-neck and the Countermeasure of Developing Our Firm Stock Market%发展我国企业债券市场的瓶颈及对策

    Institute of Scientific and Technical Information of China (English)

    马晓军

    2003-01-01

    在融资工具中,企业债券在微观和宏观方面都有着独特的作用,而我国的实际情况是企业债券市场的发展相对滞后,本文从企业债券的需求和供给两个方面对该市场发展的制约因素进行了分析,并在分析的基础上从发行制度、机构投资者、税制等方面提出了改革建议.

  7. Seven bottle-necks must be settled in the maritime investigation of today's China%当今中国海事调查面临的七大"瓶颈"

    Institute of Scientific and Technical Information of China (English)

    徐锦

    2007-01-01

    2006年开始的海事调查官资质认定工作,揭开了中国海事调查的新局面.但是,目前中国海事调查仍面临着政务公开、海事调查官素质、专家地位、权力集中、行政调解、海事调查证据理论、法律协调等多方面的问题急待解决或完善.

  8. Breaking through the "Bottle-neck" of Domestic Spare Parts Technology and Production%国产零部件应助推国产公交车走向世界

    Institute of Scientific and Technical Information of China (English)

    李季

    2007-01-01

    2007年4月的北京客车展已经落下帷幕。此次车展汇集了国内主要客车厂家的众多车型,尤其体现在公交车上,不仅外观异彩纷呈,可圈可点,车上的设施也可谓考虑周密,处处体现出人性化的设计理念;然而,美中不足的地方也暴露出来,主要体现在国产零配件的研发和配套上。

  9. 我国城乡教师交流的演变、瓶颈及策略%On the Evolution,Bottlenecks and Strategies of Teachers’ Exchange Between Urban and Rural Schools in China

    Institute of Scientific and Technical Information of China (English)

    虎技能

    2015-01-01

    我国城乡教师交流经历了从单向支援向双向轮岗演变的过程,政府、学校、教师等参与主体存在的一些问题制约着城乡教师交流的发展。采取明确交流主体的责任、完善监督评估机制、提高教师的思想认识、补偿教师的利益损失、加强交流机制的理论研究等措施,将有利于进一步推进城乡教师交流。%In China ,the teachers’ exchange between urban and ruralschools has evaluated to bi‐lateral exchange from unilateral support .The problems of government ,schools ,teachers ,and so on have restricted the development of teachers’ exchange between urban and rural schools .In order to strengthen teachers’ communication between rural and urban schools ,the following measures should be taken:to conduct definite communicative responsibility ,to improve the supervision and evaluation mechanism ,to raise the teachers’ ideological understanding ,to compensate teachers’ loss of interest , and to enhance the study of the exchange mechanism theory ,etc .

  10. Analysis of the Bottleneck Problem with Patent Marketization Mechanism at Application-Oriented Colleges and Universities in China%应用型工程院校专利市场化机制的瓶颈分析

    Institute of Scientific and Technical Information of China (English)

    李颖

    2014-01-01

    Nowadays,there are some problems with the patent marketization mechanism of China”s application-centered colle-ges and universities,for example,unclear targets,imperfect system for administration resource distribution,and unreasonable scientific and technological information service system.It is,therefore,advisable to improve the mechanism for patent mar-ketization under the guidance of the present patent marketization target,in order to develop core advantages and continuously boost the patent value.This is aimed at developing samples of patent marketization system at application-centered colleges and universities.%目前,我国现行应用型工程院校专利市场化机制存在专利市场化目标定位模糊、管理资源配置制度不完善、科技信息服务制度不合理、考核激励制度缺失等不足。需在现行专利市场化目标的指导下,完善其专利市场化机制,以期能紧扣关键、凝炼优势、聚焦瓶颈、持续增值,从而打造应用型工程院校专利市场化机制的范本。

  11. On the elimination of the electronic structure bottleneck in on the fly nonadiabatic dynamics for small to moderate sized (10-15 atom) molecules using fit diabatic representations based solely on ab initio electronic structure data: The photodissociation of phenol

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaolei, E-mail: virtualzx@gmail.com; Yarkony, David R., E-mail: yarkony@jhu.edu [Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

    2016-01-14

    In this work, we demonstrate that for moderate sized systems, here a system with 13 atoms, global coupled potential energy surfaces defined for several electronic states over a wide energy range and for distinct regions of nuclear coordinate space characterized by distinct electron configurations, can be constructed with precise energetics and an excellent description of non-adiabatic interactions in all regions. This is accomplished using a recently reported algorithm for constructing quasi-diabatic representations, H{sup d}, of adiabatic electronic states coupled by conical intersections. In this work, the algorithm is used to construct an H{sup d} to describe the photodissociation of phenol from its first and second excited electronic states. The representation treats all 33 internal degrees of freedom in an even handed manner. The ab initio adiabatic electronic structure data used to construct the fit are obtained exclusively from multireference configuration interaction with single and double excitation wave functions comprised of 88 × 10{sup 6} configuration state functions, at geometries determined by quasi-classical trajectories. Since the algorithm uses energy gradients and derivative couplings in addition to electronic energies to construct H{sup d}, data at only 7379 nuclear configurations are required to construct a representation, which describes all nuclear configurations involved in H atom photodissociation to produce the phenoxyl radical in its ground or first excited electronic state, with a mean unsigned energy error of 202.9 cm{sup −1} for electronic energies <60 000 cm{sup −1}.

  12. “Ten No”Bottlenecks Should Be Broken for Achieving Universal Health Care%全民医保亟待打破“十不”瓶颈

    Institute of Scientific and Technical Information of China (English)

    田芬

    2014-01-01

    我国基本实现全民医保,但必须清醒地看到,目前的全民医保存在着制度不统一、管理归属不明确、经办不标化,权利义务不对等,社保商保不分,对“病”的界定不清,购买服务界线不清,本地异地就医不分,风险预测不清,供需不平衡,对欺诈骗保打击不力,税费不分等问题,亟待加快治理体系和治理能力现代化。%We have basically achieved the goal of universal health care in China. However, it must be clearly realized that there are still problems such as inconsistence in systems, unclear classification in management departments, non-standardized professional criteria for insurance agencies, non-equivalence in right and duty, non-differentiation in social insurance and commercial insurance, unclear definition of “diseases”, unclear limitation in purchasing service, unclear definition in accessing local or offsite health services, unclear risk prediction, imbalance in demands and supplies, inefficiency in combating insurance fraud, unclear definition in taxes and fees. It is also urgent to accelerate the modernization of administrative system and governance capacity.

  13. Analysis on Application Bottleneck of Repairing Bone Defects with Tissue Engineered Bone%组织工程骨修复骨缺损的应用瓶颈分析

    Institute of Scientific and Technical Information of China (English)

    李凯

    2012-01-01

    Bone defects caused by bone cancer treatment are common in clinical, however the only way to repair the defects is bone graft. According to sources, the bone graft material can be divided into autogenous bone, allograft bone ,xenograft bone and artificial bone substitute materials. The rise of bone tissue engineering brings new options for the treatment of bone defects. The use of artificial bone tissue engineering training not only fixes the large area of bone defect, but also can be prepared and shaped in large quantity according to need,which makes it an ideal bone repair material. Here is to make a review' on the application status of tissue engineered bone in the treatment of bone defects.%骨肿瘤的治疗导致骨缺损很常见,修复缺损的方法是采取骨移植.骨移植材料根据来源大致可分为自体骨、同种异体骨、异种骨和人工骨替代材料.骨组织工程的兴起为骨缺损的治疗带来新的选择.利用骨组织工程培养的人工骨不仅可以修复大面积骨缺损,而且可以按需塑形并大量制备,是一种理想的骨修复材料.现就组织工程骨在治疗骨缺损中的应用现状进行综述.

  14. From Power System Operation and to Explore Its Existing Bottlenecks and Solutions%基于激励理论的煤电企业人力资源管理体系建立

    Institute of Scientific and Technical Information of China (English)

    李慧

    2013-01-01

    With the development of modern economy rapid development, coal enterprises are facing both opportunities and challenges of the new form, it is objective demand of enterprise human resources management must carry on the reform, because human resources management success or not is related to the long-term strategic development of coal enterprises. This paper first describes the motivation theory of demand, motivation, drive and behavior of four factors, based on the coal enterprise human resources management present situation analysis, integrated the four factors in order to achieve the common development of enterprises and employees for the purpose, the establishment of human resources management system, for the future of coal enterprise human resources management to provide a reliable basis.%随着现代经济的不断飞速发展,煤电企业面临机遇与挑战并存的新形式,这就客观要求企业人力资源管理必须要进行改革,因为人力资源管理的成功有否关系到整个煤电企业的长远战略发展。本文首先阐述了激励理论中的需求、动机、驱动及行为四个因素,通过对煤电企业人力资源管理现状分析,综合四个因素以达到企业与员工共同发展为目的,建立了人力资源管理体系,为今后的煤电企业人力资源管理提供了可靠的依据。

  15. 卵子线粒体老化——辅助生殖技术面临的瓶颈%Oocyte Mitochondiral Aging——Bottleneck of Assisted Reproductive Technology (ART)

    Institute of Scientific and Technical Information of China (English)

    汤江静; 尹萍; 邵敬於; 段涛; 滕晓明; 韩毅冰

    2013-01-01

    卵子老化是辅助生殖失败的一个重要原因.目前,许多妇女生育年龄不断推迟,导致卵 子老化问题日益严重.线粒体是细胞中提供能量的重要细胞器,体细胞衰老与线粒体功能异常密切相关.由于线粒体是卵子/胚胎中数量最多的细胞器,推测线粒体功能的损伤可能在卵子老化、受精成功率和体外胚胎发育方面,也起到重要作用.本文根据前人的研究成果,阐述了线粒体在卵子成熟、受精以及胚胎发育过程中的作用,分析了线粒体老化对卵子质量和受精胚胎发育的影响,证明提高卵母细胞中线粒体功能,对提高卵母细胞/体外受精胚胎的质量具有重要的意义.%"Oocyte aging" is an important cause for IVF failure and poor embryo quality. At present, many women delay their pregnancy to the later part of their childbearing years which makes "oocyte aging" a more important etiology for infertility. Mitochondrial dysfunction is associated with somatic cells senescence. Because mitochondria are the most abundant organelles in oocytes/embryos, we speculate that mitochondrial dysfunction may have an important role in oocyte maturation, fertilization and embryo development too. In this article, we have reviewed the function of mitochondria during oocyte maturation, fertilization and the following embryo development. Techniques improving mitochondrial function in the oocytes could not only prevent the oocyte aging process, but also improve the quality of embryos from assisted reproductive technology (ART).

  16. A Work-in-Process Estimation Method Based on Bottleneck Machines' Process Time Variability%基于瓶颈设备处理时间波动的WIP估计方法

    Institute of Scientific and Technical Information of China (English)

    蒋舒宇; 周炳海

    2008-01-01

    针对半导体晶圃制造系统缩短制造周期(CT)和提高产出率(TH)两个目标,考虑了瓶颈设备偏离其正常和可预测处理时间的情况(即瓶颈设备处理时间波动),结合CONWIP投料规则和G/G/m排队网络模型,开发了一种确定半导体晶圆制造系统中合理在制品(WIP)水平的启发式算法.仿真实验结果表明,在系统中保持该算法所计算出的WIP水平,在一定的瓶颈设备处理时间波动范围内可以取得合理的TH和CT.

  17. T he Reality Bottleneck and Breakthrough Path of T eachers'Virtual Living%教师虚拟生存的现实瓶颈与突围路径

    Institute of Scientific and Technical Information of China (English)

    罗儒国

    2015-01-01

    教师虚拟生存是教师为了生命发展与完善、实现生存价值与意义、提高生存质量,以各种数字化符号为中介,在虚拟世界或网络世界中进行的有目的、有意识的生存活动。然而,作为一种新型生存方式,教师虚拟生存的崛起虽然有其历史必然性与现实合理性,但也面临着教师虚拟生存意愿较为淡薄、虚拟生存能力亟待提高、虚实共生机制尚未形成、教师虚拟生存制度不够完善、虚拟生存技术条件不够成熟等方面问题。为此,需要引导教师正确认识虚拟生存价值、增强教师虚拟认同意识,加强教师教育技术培训、提升教师网络生存素养,确立虚实共生的生存图景、建立虚实和谐共生机制,强化学校信息文化建设、营造良好文化环境,以便推动教师虚拟生存的健康、有序发展。%Teachers'virtual living refers to all kinds of living activities carried by teachers in the cyber world or virtual world by digital symbols , which are aimed at developing and improving life , promoting life quality and realizing the value and significance of life . However , as a new‐type of living style , the rise of teachers'virtual living has its ow n historical inevitability and real rationality , but it also encounters some realistic plights and embarrassments which mainly involve lack of strong virtual living will , lack of digital survivability , lack of symbiotic system between virtual living and realistic living , lack of security system of teachers'virtual living . Therefore , it is necessary to have a correct understanding of virtual living value , strengthen teachers' virtual living identity , reinforce teachers' pedagogical technology training ,improve teachers'cyber living quality ,promote interaction and interpenetration between virtual living and realistic living , build an ideal virtual reality living pattern , enhance information culture construction , create a fine culture environment , so as to promote a sound development of teachers'virtual living .

  18. Bottleneck of Jiangsu sports lottery with sustainable development research%江苏省体育博彩业的瓶颈与可持续发展研究

    Institute of Scientific and Technical Information of China (English)

    黄新峰

    2011-01-01

    By using literature, investigation, theoretical analysis, the present situation of Jiangsu sports lottery and social contribution were analyzed as the unceasing innovation, operation management system, improve quality of sports in Jiangsu sports and other public welfare undertakings. It made an important contribution to the development, but public opinion direction deviation exist; Sales mode is onefold; Lottery legislation is backward; The sport lottery classes and functions need further improving, It puts forward the countermeasures of sustainable development in Jiangsu lottery.%运用文献、调查、理论分析等方法,对江苏省体育彩票的现状及对社会的贡献进行分析,认为管理体制不断创新,运行质量不断提升,体彩公益金对江苏省的体育及其他社会公益事业做出了重要的贡献,但在发展过程中存在着舆论导向的偏差;销售方式较单一;彩票立法滞后;体育彩票的种类和功能有待进一步挖掘等问题,并进一步提出了江苏省体票可持续发展的对策。

  19. Bus and Coach Market Research Methodology and Analysis of and Solutions to the Bottle-neck Issue%客车市场研究方法及瓶颈问题解析

    Institute of Scientific and Technical Information of China (English)

    杨立慧

    2010-01-01

    @@ 引入战略思维,提升客车市场研究高度 引入战略思维就是通过有效组合企业内部资源,在变化的环境中确定企业发展方向和经营范围,从而获得竞争优势,以满足市场需求和企业拥有人的需求;因此,战略的核心问题就是在解决市场竞争能力基础上,达到企业资源效益最大化.其作用主要体现在2方面.

  20. How to Breakthrough the Bottleneck of the Development of Animation Specialty in Colleges%谈如何突破高校动漫专业发展的瓶颈

    Institute of Scientific and Technical Information of China (English)

    佘东; 周守东

    2012-01-01

      According to the analysis of the animation specialty development situation, employment characteristics of graduates and animation employee demand, we put forward some suggestions on animation specialty development, such as strengthening innovation education , paying attention to the animation scene localization and culturing The inclusive education concept of the ACG. We establish project teaching as the core of the reform of training scheme, and finally we can find the methods of solving the development problem of animation specialty.%  通过分析动漫专业发展现状,结合毕业生就业特点和动漫专业需求分析进行问题剖析,提出了加强创新教育,注重动漫场景本土化,培养ACG时代的融合教育理念,建立以项目式为核心人才培养方案改革,解决动漫专业发展瓶颈的方法。