Taxi Cab Syndrome: A Review of the Extensive Genitourinary Pathology Experienced by Taxi Cab Drivers and What We Can Do to Help

PubMed Central

Mass, Alon Y; Goldfarb, David S; Shah, Ojas

2014-01-01

This review consolidates knowledge regarding the extensive genitourinary pathology experienced by taxi cab drivers. Taxi cab, livery, truck, and other drivers all objectively and subjectively may have more voiding dysfunction, infertility, urolithiasis, bladder cancer, and urinary infections as compared with nonprofessional drivers; this is called taxi cab syndrome. Together with governmental and medical assistance, simple interventions—such as education, the addition of taxi relief stations, and possibly the use of sanitary urinary collection devices—to curb the progression of genitourinary disease in taxi drivers should be prospectively studied. It is postulated that many of these interventions may also benefit other groups of occupationally related infrequent voiders. PMID:25337038

14 CFR 23.1383 - Taxi and landing lights.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Taxi and landing lights. 23.1383 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Lights § 23.1383 Taxi and landing lights. Each taxi and landing light must be designed and installed so that: (a) No...

14 CFR 23.1383 - Taxi and landing lights.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Taxi and landing lights. 23.1383 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Lights § 23.1383 Taxi and landing lights. Each taxi and landing light must be designed and installed so that: (a) No...

14 CFR 23.1383 - Taxi and landing lights.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Taxi and landing lights. 23.1383 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Lights § 23.1383 Taxi and landing lights. Each taxi and landing light must be designed and installed so that: (a) No...

14 CFR 23.1383 - Taxi and landing lights.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Taxi and landing lights. 23.1383 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Lights § 23.1383 Taxi and landing lights. Each taxi and landing light must be designed and installed so that: (a) No...

Structural controllability of unidirectional bipartite networks

NASA Astrophysics Data System (ADS)

Nacher, Jose C.; Akutsu, Tatsuya

2013-04-01

The interactions between fundamental life molecules, people and social organisations build complex architectures that often result in undesired behaviours. Despite all of the advances made in our understanding of network structures over the past decade, similar progress has not been achieved in the controllability of real-world networks. In particular, an analytical framework to address the controllability of bipartite networks is still absent. Here, we present a dominating set (DS)-based approach to bipartite network controllability that identifies the topologies that are relatively easy to control with the minimum number of driver nodes. Our theoretical calculations, assisted by computer simulations and an evaluation of real-world networks offer a promising framework to control unidirectional bipartite networks. Our analysis should open a new approach to reverting the undesired behaviours in unidirectional bipartite networks at will.

Bipartite flocking for multi-agent systems

NASA Astrophysics Data System (ADS)

Fan, Ming-Can; Zhang, Hai-Tao; Wang, Miaomiao

2014-09-01

This paper addresses the bipartite flock control problem where a multi-agent system splits into two clusters upon internal or external excitations. Using structurally balanced signed graph theory, LaSalle's invariance principle and Barbalat's Lemma, we prove that the proposed algorithm guarantees a bipartite flocking behavior. In each of the two disjoint clusters, all individuals move with the same direction. Meanwhile, every pair of agents in different clusters moves with opposite directions. Moreover, all agents in the two separated clusters approach a common velocity magnitude, and collision avoidance among all agents is ensured as well. Finally, the proposed bipartite flock control method is examined by numerical simulations. The bipartite flocking motion addressed by this paper has its references in both natural collective motions and human group behaviors such as predator-prey and panic escaping scenarios.

The impact of rainfall on the temporal and spatial distribution of taxi passengers

PubMed Central

Zhang, Yong; Gao, Liangpeng; Geng, Nana; Li, Xuefeng

2017-01-01

This paper focuses on the impact of rainfall on the temporal and spatial distribution of taxi passengers. The main objective is to provide guidance for taxi scheduling on rainy days. To this end, we take the occupied and empty states of taxis as units of analysis. By matching a taxi's GPS data to its taximeter data, we can obtain the taxi's operational time and the taxi driver's income from every unit of analysis. The ratio of taxi operation time to taxi drivers' income is used to measure the quality of taxi passengers. The research results show that the spatio-temporal evolution of urban taxi service demand differs based on rainfall conditions and hours of operation. During non-rush hours, taxi demand in peripheral areas is significantly reduced under increasing precipitation conditions, whereas during rush hours, the demand for highly profitable taxi services steadily increases. Thus, as an intelligent response for taxi operations and dispatching, taxi services should guide cruising taxis to high-demand regions to increase their service time and ride opportunities. PMID:28873430

49 CFR 37.29 - Private entities providing taxi service.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Private entities providing taxi service. 37.29... INDIVIDUALS WITH DISABILITIES (ADA) Applicability § 37.29 Private entities providing taxi service. (a) Providers of taxi service are subject to the requirements of this part for private entities primarily...

49 CFR 37.29 - Private entities providing taxi service.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 1 2011-10-01 2011-10-01 false Private entities providing taxi service. 37.29... INDIVIDUALS WITH DISABILITIES (ADA) Applicability § 37.29 Private entities providing taxi service. (a) Providers of taxi service are subject to the requirements of this part for private entities primarily...

A novel community detection method in bipartite networks

NASA Astrophysics Data System (ADS)

Zhou, Cangqi; Feng, Liang; Zhao, Qianchuan

2018-02-01

Community structure is a common and important feature in many complex networks, including bipartite networks, which are used as a standard model for many empirical networks comprised of two types of nodes. In this paper, we propose a two-stage method for detecting community structure in bipartite networks. Firstly, we extend the widely-used Louvain algorithm to bipartite networks. The effectiveness and efficiency of the Louvain algorithm have been proved by many applications. However, there lacks a Louvain-like algorithm specially modified for bipartite networks. Based on bipartite modularity, a measure that extends unipartite modularity and that quantifies the strength of partitions in bipartite networks, we fill the gap by developing the Bi-Louvain algorithm that iteratively groups the nodes in each part by turns. This algorithm in bipartite networks often produces a balanced network structure with equal numbers of two types of nodes. Secondly, for the balanced network yielded by the first algorithm, we use an agglomerative clustering method to further cluster the network. We demonstrate that the calculation of the gain of modularity of each aggregation, and the operation of joining two communities can be compactly calculated by matrix operations for all pairs of communities simultaneously. At last, a complete hierarchical community structure is unfolded. We apply our method to two benchmark data sets and a large-scale data set from an e-commerce company, showing that it effectively identifies community structure in bipartite networks.

Standardization of databases for AMDB taxi routing functions

NASA Astrophysics Data System (ADS)

Pschierer, C.; Sindlinger, A.; Schiefele, J.

2010-04-01

Input, management, and display of taxi routes on airport moving map displays (AMM) have been covered in various studies in the past. The demonstrated applications are typically based on Aerodrome Mapping Databases (AMDB). Taxi routing functions require specific enhancements, typically in the form of a graph network with nodes and edges modeling all connectivities within an airport, which are not supported by the current AMDB standards. Therefore, the data schemas and data content have been defined specifically for the purpose and test scenarios of these studies. A standardization of the data format for taxi routing information is a prerequisite for turning taxi routing functions into production. The joint RTCA/EUROCAE special committee SC-217, responsible for updating and enhancing the AMDB standards DO-272 [1] and DO-291 [2], is currently in the process of studying different alternatives and defining reasonable formats. Requirements for taxi routing data are primarily driven by depiction concepts for assigned and cleared taxi routes, but also by database size and the economic feasibility. Studied concepts are similar to the ones described in the GDF (geographic data files) specification [3], which is used in most car navigation systems today. They include - A highly aggregated graph network of complex features - A modestly aggregated graph network of simple features - A non-explicit topology of plain AMDB taxi guidance line elements This paper introduces the different concepts and their advantages and disadvantages.

Community detection for networks with unipartite and bipartite structure

NASA Astrophysics Data System (ADS)

Chang, Chang; Tang, Chao

2014-09-01

Finding community structures in networks is important in network science, technology, and applications. To date, most algorithms that aim to find community structures only focus either on unipartite or bipartite networks. A unipartite network consists of one set of nodes and a bipartite network consists of two nonoverlapping sets of nodes with only links joining the nodes in different sets. However, a third type of network exists, defined here as the mixture network. Just like a bipartite network, a mixture network also consists of two sets of nodes, but some nodes may simultaneously belong to two sets, which breaks the nonoverlapping restriction of a bipartite network. The mixture network can be considered as a general case, with unipartite and bipartite networks viewed as its limiting cases. A mixture network can represent not only all the unipartite and bipartite networks, but also a wide range of real-world networks that cannot be properly represented as either unipartite or bipartite networks in fields such as biology and social science. Based on this observation, we first propose a probabilistic model that can find modules in unipartite, bipartite, and mixture networks in a unified framework based on the link community model for a unipartite undirected network [B Ball et al (2011 Phys. Rev. E 84 036103)]. We test our algorithm on synthetic networks (both overlapping and nonoverlapping communities) and apply it to two real-world networks: a southern women bipartite network and a human transcriptional regulatory mixture network. The results suggest that our model performs well for all three types of networks, is competitive with other algorithms for unipartite or bipartite networks, and is applicable to real-world networks.

Separable decompositions of bipartite mixed states

NASA Astrophysics Data System (ADS)

Li, Jun-Li; Qiao, Cong-Feng

2018-04-01

We present a practical scheme for the decomposition of a bipartite mixed state into a sum of direct products of local density matrices, using the technique developed in Li and Qiao (Sci. Rep. 8:1442, 2018). In the scheme, the correlation matrix which characterizes the bipartite entanglement is first decomposed into two matrices composed of the Bloch vectors of local states. Then, we show that the symmetries of Bloch vectors are consistent with that of the correlation matrix, and the magnitudes of the local Bloch vectors are lower bounded by the correlation matrix. Concrete examples for the separable decompositions of bipartite mixed states are presented for illustration.

Design Reference Missions (DRM): Integrated ODM 'Air-Taxi' Mission Features

NASA Technical Reports Server (NTRS)

Kloesel, Kurt; Starr, Ginn; Saltzman, John A.

2017-01-01

Design Reference Missions (DRM): Integrated ODM Air-Taxi Mission Features, Hybrid Electric Integrated System Testbed (HEIST) flight control. Structural Health, Energy Storage, Electric Components, Loss of Control, Degraded Systems, System Health, Real-Time IO Operator Geo-Fencing, Regional Noise Abatement and Trusted Autonomy Inter-operability.

Impact of urban built environment on urban short-distance taxi travel: the case of Shanghai

NASA Astrophysics Data System (ADS)

Wu, Zhuoye; Zhuo, Jian

2018-05-01

The excessive individual motorized transport is the main cause of urban congestion and generates negative consequences on urban environmental quality, energy consumption, infrastructure supply and urban security. Bicycle can compete effectively with automobile for short-distance travels within 3km. If we take action to encourage the rider to shift from automobile to bike for the short-distance travels, it leaves us a great chance to reduce the modal share of individual motorized mode. This paper focus on the spatial impact of built environment on short-distance taxi riders’ travel behaviour. The data sources include taxi trajectory data for a week, demographic data of the Sixth National Census, POI data. In this paper, we figure out the volumes and spatial distribution of short-distance taxi travel in the central city of Shanghai. We build a multiple regression model to quantitative analyze the impact of urban built environment on urban short-distance taxi travel. The findings explain the spatial distribution short-distance taxi travel. In the conclusion, some advice are provided on how planners change the spatial settings to discourage short-distance individual motorized travel.

Quantum open system theory: bipartite aspects.

PubMed

Yu, T; Eberly, J H

2006-10-06

We demonstrate in straightforward calculations that even under ideally weak noise the relaxation of bipartite open quantum systems contains elements not previously encountered in quantum noise physics. While additivity of decay rates is known to be generic for decoherence of a single system, we demonstrate that it breaks down for bipartite coherence of even the simplest composite systems.

Fuel Consumption and Emissions from Airport Taxi Operations

NASA Technical Reports Server (NTRS)

Jung, Yoon

2010-01-01

Developed a method to calculate fuel consumption and emissions of phases of taxi operations. Results at DFW showed that up to 18% of fuel can be saved by eliminating stop-and-go situations. Developed an energy efficient and environmentally friendly surface concept: Spot and Runway Departure Advisory (SARDA) tool. The SARDA tool has been identified as a potential candidate for a technology transfer to the FAA.

14 CFR 294.3 - General requirements for Canadian charter air taxi operators.

Code of Federal Regulations, 2011 CFR

2011-01-01

... air taxi operators. 294.3 Section 294.3 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS General § 294.3 General requirements for Canadian charter air taxi operators. A Canadian charter air taxi operator shall...

14 CFR 294.3 - General requirements for Canadian charter air taxi operators.

Code of Federal Regulations, 2010 CFR

2010-01-01

... air taxi operators. 294.3 Section 294.3 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS General § 294.3 General requirements for Canadian charter air taxi operators. A Canadian charter air taxi operator shall...

A Study Examining Compliance with the Anti-Tobacco Law Nb. 4207 Inside Taxis

PubMed Central

Öztürk, Burcu; Kosku, Hakan; Güven, İbrahim; Erdoğan, Beyza; Sarıtaş, Özge; Şanver, Tuğçe; Aslan, Dilek

2017-01-01

OBJECTIVES This observational study assessed compliance with the anti-tobacco Law Nb 4207 with regard to taxis in Çankaya district, Ankara. MATERIAL AND METHODS This descriptive study was conducted in Kızılay, Kuğulu, and Tandoğan intersections on January 18–23, 2016 between 9.00–11.00 and 14.00–16.00 hours in Ankara. Data regarding the status of the taxi (either cruising or not), smoking inside taxis, smoking status of the taxi drivers and/or clients, location of the clients in the taxi, presence of a child in the taxi, and status of the windows (open or not) were recorded using a data-gathering form. RESULTS Three thousand six hundred fifty-six taxis were evaluated, of which 79 (2.2%) taxi drivers were observed smoking. Clients were observed smoking in 17 taxis (1.3%). Ninety-four taxi drivers and/or clients (2.6%) were observed smoking. Taxi drivers smoked more frequently in the absence of a client. In addition, a smoking client influenced the taxi driver’s smoking status (p<0.001). CONCLUSION Violation of the anti-tobacco Law Nb 4207 was observed. In this regard, the number of inspections needs to be increased. Systematic training programs for the taxi drivers regarding the risks of tobacco should be a priority. Preventive studies concerning the hazards of passive smoking should be also conducted at a community level. PMID:29404168

Analyzing Impact Factors of Airport Taxiing Delay Based on Ads-B Data

NASA Astrophysics Data System (ADS)

Li, J.; Wang, X.; Xu, Y.; Li, Q.; He, C.; Li, Y.

2017-09-01

Identifying the factors that cause taxiing delay on airports is a prerequisite for optimizing aircraft taxiing schemes, and helps improve the efficiency of taxiing system. Few of current studies had quantified the potential influencing factors and further investigated their intrinsic relationship. In view of these problems, this paper uses ADS-B data to calculate taxiing delay time by restoring taxiing route and identifying key status points, and further analyzes the impact factors of airport taxiing delay by investigating the relationship between delay time and environmental data such as weather, wind, visibility etc. The case study in Guangzhou Baiyun Airport validates the effectiveness of the proposed method.

Bipartite units of nonlocality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forster, Manuel; Wolf, Stefan

Imagine a task in which a group of separated players aim to simulate a statistic that violates a Bell inequality. Given measurement choices the players shall announce an output based solely on the results of local operations--which they can discuss before the separation--on shared random data and shared copies of a so-called unit correlation. In the first part of this paper we show that in such a setting the simulation of any bipartite correlation, not containing the possibility of signaling, can be made arbitrarily accurate by increasing the number of shared Popescu-Rohrlich (PR) boxes. This establishes the PR box asmore » a simple asymptotic unit of bipartite nonlocality. In the second part we study whether this property extends to the multipartite case. More generally, we ask if it is possible for separated players to asymptotically reproduce any nonsignaling statistic by local operations on bipartite unit correlations. We find that nonadaptive strategies are limited by a constant accuracy and that arbitrary strategies on n resource correlations make a mistake with a probability greater or equal to c/n, for some constant c.« less

Taxi-cabs as Subjects for a Population Study

ERIC Educational Resources Information Center

Bishop, J. A.; Bradley, J. S.

1972-01-01

Describes the use of capture-recapture techniques to estimate the population of taxis in Liverpool and demonstrates the points of similarity to animal population estimation. Considers advantages of studying taxis rather than organisms in introductory studies of the techniques. (AL)

a Web-Based Platform for Visualizing Spatiotemporal Dynamics of Big Taxi Data

NASA Astrophysics Data System (ADS)

Xiong, H.; Chen, L.; Gui, Z.

2017-09-01

With more and more vehicles equipped with Global Positioning System (GPS), access to large-scale taxi trajectory data has become increasingly easy. Taxis are valuable sensors and information associated with taxi trajectory can provide unprecedented insight into many aspects of city life. But analysing these data presents many challenges. Visualization of taxi data is an efficient way to represent its distributions and structures and reveal hidden patterns in the data. However, Most of the existing visualization systems have some shortcomings. On the one hand, the passenger loading status and speed information cannot be expressed. On the other hand, mono-visualization form limits the information presentation. In view of these problems, this paper designs and implements a visualization system in which we use colour and shape to indicate passenger loading status and speed information and integrate various forms of taxi visualization. The main work as follows: 1. Pre-processing and storing the taxi data into MongoDB database. 2. Visualization of hotspots for taxi pickup points. Through DBSCAN clustering algorithm, we cluster the extracted taxi passenger's pickup locations to produce passenger hotspots. 3. Visualizing the dynamic of taxi moving trajectory using interactive animation. We use a thinning algorithm to reduce the amount of data and design a preloading strategyto load the data smoothly. Colour and shape are used to visualize the taxi trajectory data.

System dynamics model of taxi management in metropolises: Economic and environmental implications for Beijing.

PubMed

Wang, Hao; Zhang, Kai; Chen, Junhua; Wang, Zhifeng; Li, Guijun; Yang, Yuqi

2018-05-01

Taxis are an important component of urban passenger transport. Research on the daily dispatching of taxis and the utility of governmental management is important for the improvement of passenger travel, taxi driver income and environmental impacts. However, urban taxi management is a complex and dynamic system that is affected by many factors, and positive/negative feedback relationships and nonlinear interactions exist between each subsystem and variable. Therefore, conventional research methods can hardly depict its characteristics comprehensively. To bridge this gap, this paper develops a system dynamics model of urban taxi management, in which the empty-loaded rate and total demand are selected as key factors affecting taxi dispatching, and the impacts of taxi fares on driver income and travel demand are taken into account. After the validation of the model, taxi operations data derived from a prior analysis of origin-destination data of Beijing taxis are used as input for the model to simulate the taxi market in Beijing. Finally, economic and environmental implications are provided for the government to optimise policies on taxi management. Copyright © 2018 Elsevier Ltd. All rights reserved.

Pilot age and error in air taxi crashes.

PubMed

Rebok, George W; Qiang, Yandong; Baker, Susan P; Li, Guohua

2009-07-01

The associations of pilot error with the type of flight operations and basic weather conditions are well documented. The correlation between pilot characteristics and error is less clear. This study aims to examine whether pilot age is associated with the prevalence and patterns of pilot error in air taxi crashes. Investigation reports from the National Transportation Safety Board for crashes involving non-scheduled Part 135 operations (i.e., air taxis) in the United States between 1983 and 2002 were reviewed to identify pilot error and other contributing factors. Crash circumstances and the presence and type of pilot error were analyzed in relation to pilot age using Chi-square tests. Of the 1751 air taxi crashes studied, 28% resulted from mechanical failure, 25% from loss of control at landing or takeoff, 7% from visual flight rule conditions into instrument meteorological conditions, 7% from fuel starvation, 5% from taxiing, and 28% from other causes. Crashes among older pilots were more likely to occur during the daytime rather than at night and off airport than on airport. The patterns of pilot error in air taxi crashes were similar across age groups. Of the errors identified, 27% were flawed decisions, 26% were inattentiveness, 23% mishandled aircraft kinetics, 15% mishandled wind and/or runway conditions, and 11% were others. Pilot age is associated with crash circumstances but not with the prevalence and patterns of pilot error in air taxi crashes. Lack of age-related differences in pilot error may be attributable to the "safe worker effect."

Pilot Age and Error in Air-Taxi Crashes

PubMed Central

Rebok, George W.; Qiang, Yandong; Baker, Susan P.; Li, Guohua

2010-01-01

Introduction The associations of pilot error with the type of flight operations and basic weather conditions are well documented. The correlation between pilot characteristics and error is less clear. This study aims to examine whether pilot age is associated with the prevalence and patterns of pilot error in air-taxi crashes. Methods Investigation reports from the National Transportation Safety Board for crashes involving non-scheduled Part 135 operations (i.e., air taxis) in the United States between 1983 and 2002 were reviewed to identify pilot error and other contributing factors. Crash circumstances and the presence and type of pilot error were analyzed in relation to pilot age using Chi-square tests. Results Of the 1751 air-taxi crashes studied, 28% resulted from mechanical failure, 25% from loss of control at landing or takeoff, 7% from visual flight rule conditions into instrument meteorological conditions, 7% from fuel starvation, 5% from taxiing, and 28% from other causes. Crashes among older pilots were more likely to occur during the daytime rather than at night and off airport than on airport. The patterns of pilot error in air-taxi crashes were similar across age groups. Of the errors identified, 27% were flawed decisions, 26% were inattentiveness, 23% mishandled aircraft kinetics, 15% mishandled wind and/or runway conditions, and 11% were others. Conclusions Pilot age is associated with crash circumstances but not with the prevalence and patterns of pilot error in air-taxi crashes. Lack of age-related differences in pilot error may be attributable to the “safe worker effect.” PMID:19601508

Evolutionary method for finding communities in bipartite networks.

PubMed

Zhan, Weihua; Zhang, Zhongzhi; Guan, Jihong; Zhou, Shuigeng

2011-06-01

An important step in unveiling the relation between network structure and dynamics defined on networks is to detect communities, and numerous methods have been developed separately to identify community structure in different classes of networks, such as unipartite networks, bipartite networks, and directed networks. Here, we show that the finding of communities in such networks can be unified in a general framework-detection of community structure in bipartite networks. Moreover, we propose an evolutionary method for efficiently identifying communities in bipartite networks. To this end, we show that both unipartite and directed networks can be represented as bipartite networks, and their modularity is completely consistent with that for bipartite networks, the detection of modular structure on which can be reformulated as modularity maximization. To optimize the bipartite modularity, we develop a modified adaptive genetic algorithm (MAGA), which is shown to be especially efficient for community structure detection. The high efficiency of the MAGA is based on the following three improvements we make. First, we introduce a different measure for the informativeness of a locus instead of the standard deviation, which can exactly determine which loci mutate. This measure is the bias between the distribution of a locus over the current population and the uniform distribution of the locus, i.e., the Kullback-Leibler divergence between them. Second, we develop a reassignment technique for differentiating the informative state a locus has attained from the random state in the initial phase. Third, we present a modified mutation rule which by incorporating related operations can guarantee the convergence of the MAGA to the global optimum and can speed up the convergence process. Experimental results show that the MAGA outperforms existing methods in terms of modularity for both bipartite and unipartite networks.

14 CFR 298.52 - Air taxi operations by commuter air carriers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A commuter...

14 CFR 298.52 - Air taxi operations by commuter air carriers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A commuter...

14 CFR 298.52 - Air taxi operations by commuter air carriers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A commuter...

14 CFR 298.52 - Air taxi operations by commuter air carriers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A commuter...

14 CFR 298.52 - Air taxi operations by commuter air carriers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A commuter...

Expanding the Definition of the Classical Bipartite Nuclear Localization Signal

PubMed Central

Lange, Allison; McLane, Laura M.; Mills, Ryan E.; Devine, Scott E.; Corbett, Anita H.

2010-01-01

Nuclear localization signals (NLSs) are amino acid sequences that target cargo proteins into the nucleus. Rigorous characterization of NLS motifs is essential to understanding and predicting pathways for nuclear import. The best-characterized NLS is the classical NLS (cNLS), which is recognized by the cNLS receptor, importin-α. cNLSs are conventionally defined as having one (monopartite) or two clusters of basic amino acids separated by a 9-12 amino acid linker (bipartite). Motivated by the finding that Ty1 integrase, which contains an unconventional putative bipartite cNLS with a 29 amino acid linker, exploits the classical nuclear import machinery, we assessed the functional boundaries for linker length within a bipartite cNLS. We confirmed that the integrase cNLS is a bona fide bipartite cNLS, then carried out a systematic analysis of linker length in an obligate bipartite cNLS cargo, which revealed that some linkers longer than conventionally defined can function in nuclear import. Linker function is dependent on the sequence and likely the inherent flexibility of the linker. Subsequently, we interrogated the Saccharomyces cerevisiae proteome to identify cellular proteins containing putative long bipartite cNLSs. We experimentally confirmed that Rrp4 contains a bipartite cNLS with a 25 amino acid linker. Our studies reveal that the traditional definition of bipartite cNLSs is too restrictive and linker length can vary depending on amino acid composition PMID:20028483

Data transfer using complete bipartite graph

NASA Astrophysics Data System (ADS)

Chandrasekaran, V. M.; Praba, B.; Manimaran, A.; Kailash, G.

2017-11-01

Information exchange extent is an estimation of the amount of information sent between two focuses on a framework in a given time period. It is an extremely significant perception in present world. There are many ways of message passing in the present situations. Some of them are through encryption, decryption, by using complete bipartite graph. In this paper, we recommend a method for communication using messages through encryption of a complete bipartite graph.

Charging Guidance of Electric Taxis Based on Adaptive Particle Swarm Optimization

PubMed Central

Niu, Liyong; Zhang, Di

2015-01-01

Electric taxis are playing an important role in the application of electric vehicles. The actual operational data of electric taxis in Shenzhen, China, is analyzed, and, in allusion to the unbalanced time availability of the charging station equipment, the electric taxis charging guidance system is proposed basing on the charging station information and vehicle information. An electric taxis charging guidance model is established and guides the charging based on the positions of taxis and charging stations with adaptive mutation particle swarm optimization. The simulation is based on the actual data of Shenzhen charging stations, and the results show that electric taxis can be evenly distributed to the appropriate charging stations according to the charging pile numbers in charging stations after the charging guidance. The even distribution among the charging stations in the area will be achieved and the utilization of charging equipment will be improved, so the proposed charging guidance method is verified to be feasible. The improved utilization of charging equipment can save public charging infrastructure resources greatly. PMID:26236770

Charging Guidance of Electric Taxis Based on Adaptive Particle Swarm Optimization.

PubMed

Niu, Liyong; Zhang, Di

2015-01-01

Electric taxis are playing an important role in the application of electric vehicles. The actual operational data of electric taxis in Shenzhen, China, is analyzed, and, in allusion to the unbalanced time availability of the charging station equipment, the electric taxis charging guidance system is proposed basing on the charging station information and vehicle information. An electric taxis charging guidance model is established and guides the charging based on the positions of taxis and charging stations with adaptive mutation particle swarm optimization. The simulation is based on the actual data of Shenzhen charging stations, and the results show that electric taxis can be evenly distributed to the appropriate charging stations according to the charging pile numbers in charging stations after the charging guidance. The even distribution among the charging stations in the area will be achieved and the utilization of charging equipment will be improved, so the proposed charging guidance method is verified to be feasible. The improved utilization of charging equipment can save public charging infrastructure resources greatly.

Seatbelt use amongst taxi drivers in Beijing, China.

PubMed

Passmore, J; Ozanne-Smith, J

2006-09-01

Associated with explosive growth in motorization, China has the world's highest road toll with more than 100,000 deaths and 400,000 injuries annually. In response, the Chinese Government introduced the first road traffic safety law in 2003, which included mandatory use of seatbelts by drivers and front seat passengers. Noting frequent non-compliance to this seatbelt regulation by Beijing taxi drivers, the authors studied seatbelt use patterns as onboard observers in a convenience sample of 235 taxi trips. Findings indicated a low seatbelt-wearing rate among taxi drivers of 7.7%, an overt non-wearing rate of 57%, covert non-wearing of 35.3% and total non-compliance of 92.3%. As in high-income countries, adoption of proven safety strategies, including wearing safety restraints, could contribute to reducing the Chinese road toll, particularly as vehicle occupant numbers and the availability of restraints increases. Further investigation of reasons for non-compliance and pretense of wearing seatbelts is required to inform future seatbelt-wearing promotions, including attitudinal studies of taxi drivers. Seatbelt wearing rates should continue to be monitored.

Analysis of ground state in random bipartite matching

NASA Astrophysics Data System (ADS)

Shi, Gui-Yuan; Kong, Yi-Xiu; Liao, Hao; Zhang, Yi-Cheng

2016-02-01

Bipartite matching problems emerge in many human social phenomena. In this paper, we study the ground state of the Gale-Shapley model, which is the most popular bipartite matching model. We apply the Kuhn-Munkres algorithm to compute the numerical ground state of the model. For the first time, we obtain the number of blocking pairs which is a measure of the system instability. We also show that the number of blocking pairs formed by each person follows a geometric distribution. Furthermore, we study how the connectivity in the bipartite matching problems influences the instability of the ground state.

Comparing taxi clearance input layouts for advancements in flight deck automation for surface operations

NASA Astrophysics Data System (ADS)

Cheng, Lara W. S.

Airport moving maps (AMMs) have been shown to decrease navigation errors, increase taxiing speed, and reduce workload when they depict airport layout, current aircraft position, and the cleared taxi route. However, current technologies are limited in their ability to depict the cleared taxi route due to the unavailability of datacomm or other means of electronically transmitting clearances from ATC to the flight deck. This study examined methods by which pilots can input ATC-issued taxi clearances to support taxi route depictions on the AMM. Sixteen general aviation (GA) pilots used a touchscreen monitor to input taxi clearances using two input layouts, softkeys and QWERTY, each with and without feedforward (graying out invalid inputs). QWERTY yielded more taxi route input errors than the softkeys layout. The presence of feedforward did not produce fewer taxi route input errors than in the non-feedforward condition. The QWERTY layout did reduce taxi clearance input times relative to the softkeys layout, but when feedforward was present this effect was observed only for the longer, 6-segment taxi clearances. It was observed that with the softkeys layout, feedforward reduced input times compared to non-feedforward but only for the 4-segment clearances. Feedforward did not support faster taxi clearance input times for the QWERTY layout. Based on the results and analyses of the present study, it is concluded that for taxi clearance inputs, (1) QWERTY remain the standard for alphanumeric inputs, and (2) feedforward be investigated further, with a focus on participant preference and performance of black-gray contrast of keys.

Effects of Taxi Regulatory Revision in San Diego, California

DOT National Transportation Integrated Search

1983-05-01

Effective January 1979 the City of San Diego removed its previous ceiling on taxi licenses and began issuing 6 new taxi permits every month; in July, this limit was raised to 15. In August, the city replaced the standard rate of fare with a variable ...

Uncovering urban human mobility from large scale taxi GPS data

NASA Astrophysics Data System (ADS)

Tang, Jinjun; Liu, Fang; Wang, Yinhai; Wang, Hua

2015-11-01

Taxi GPS trajectories data contain massive spatial and temporal information of urban human activity and mobility. Taking taxi as mobile sensors, the information derived from taxi trips benefits the city and transportation planning. The original data used in study are collected from more than 1100 taxi drivers in Harbin city. We firstly divide the city area into 400 different transportation districts and analyze the origin and destination distribution in urban area on weekday and weekend. The Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm is used to cluster pick-up and drop-off locations. Furthermore, four spatial interaction models are calibrated and compared based on trajectories in shopping center of Harbin city to study the pick-up location searching behavior. By extracting taxi trips from GPS data, travel distance, time and average speed in occupied and non-occupied status are then used to investigate human mobility. Finally, we use observed OD matrix of center area in Harbin city to model the traffic distribution patterns based on entropy-maximizing method, and the estimation performance verify its effectiveness in case study.

A Mixed Integer Linear Program for Solving a Multiple Route Taxi Scheduling Problem

NASA Technical Reports Server (NTRS)

Montoya, Justin Vincent; Wood, Zachary Paul; Rathinam, Sivakumar; Malik, Waqar Ahmad

2010-01-01

Aircraft movements on taxiways at busy airports often create bottlenecks. This paper introduces a mixed integer linear program to solve a Multiple Route Aircraft Taxi Scheduling Problem. The outputs of the model are in the form of optimal taxi schedules, which include routing decisions for taxiing aircraft. The model extends an existing single route formulation to include routing decisions. An efficient comparison framework compares the multi-route formulation and the single route formulation. The multi-route model is exercised for east side airport surface traffic at Dallas/Fort Worth International Airport to determine if any arrival taxi time savings can be achieved by allowing arrivals to have two taxi routes: a route that crosses an active departure runway and a perimeter route that avoids the crossing. Results indicate that the multi-route formulation yields reduced arrival taxi times over the single route formulation only when a perimeter taxiway is used. In conditions where the departure aircraft are given an optimal and fixed takeoff sequence, accumulative arrival taxi time savings in the multi-route formulation can be as high as 3.6 hours more than the single route formulation. If the departure sequence is not optimal, the multi-route formulation results in less taxi time savings made over the single route formulation, but the average arrival taxi time is significantly decreased.

Measuring and modeling air exchange rates inside taxi cabs in Los Angeles, California

NASA Astrophysics Data System (ADS)

Shu, Shi; Yu, Nu; Wang, Yueyan; Zhu, Yifang

2015-12-01

Air exchange rates (AERs) have a direct impact on traffic-related air pollutant (TRAP) levels inside vehicles. Taxi drivers are occupationally exposed to TRAP on a daily basis, yet there is limited measurement of AERs in taxi cabs. To fill this gap, AERs were quantified in 22 representative Los Angeles taxi cabs including 10 Prius, 5 Crown Victoria, 3 Camry, 3 Caravan, and 1 Uplander under realistic driving (RD) conditions. To further study the impacts of window position and ventilation settings on taxi AERs, additional tests were conducted on 14 taxis with windows closed (WC) and on the other 8 taxis with not only windows closed but also medium fan speed (WC-MFS) under outdoor air mode. Under RD conditions, the AERs in all 22 cabs had a mean of 63 h-1 with a median of 38 h-1. Similar AERs were observed under WC condition when compared to those measured under RD condition. Under WC-MFS condition, AERs were significantly increased in all taxi cabs, when compared with those measured under RD condition. A General Estimating Equation (GEE) model was developed and the modeling results showed that vehicle model was a significant factor in determining the AERs in taxi cabs under RD condition. Driving speed and car age were positively associated with AERs but not statistically significant. Overall, AERs measured in taxi cabs were much higher than typical AERs people usually encounter in indoor environments such as homes, offices, and even regular passenger vehicles.

Mining spatiotemporal patterns of urban dwellers from taxi trajectory data

NASA Astrophysics Data System (ADS)

Mao, Feng; Ji, Minhe; Liu, Ting

2016-06-01

With the widespread adoption of locationaware technology, obtaining long-sequence, massive and high-accuracy spatiotemporal trajectory data of individuals has become increasingly popular in various geographic studies. Trajectory data of taxis, one of the most widely used inner-city travel modes, contain rich information about both road network traffic and travel behavior of passengers. Such data can be used to study the microscopic activity patterns of individuals as well as the macro system of urban spatial structures. This paper focuses on trajectories obtained from GPS-enabled taxis and their applications for mining urban commuting patterns. A novel approach is proposed to discover spatiotemporal patterns of household travel from the taxi trajectory dataset with a large number of point locations. The approach involves three critical steps: spatial clustering of taxi origin-destination (OD) based on urban traffic grids to discover potentially meaningful places, identifying threshold values from statistics of the OD clusters to extract urban jobs-housing structures, and visualization of analytic results to understand the spatial distribution and temporal trends of the revealed urban structures and implied household commuting behavior. A case study with a taxi trajectory dataset in Shanghai, China is presented to demonstrate and evaluate the proposed method.

Taxi, Jitneys and Poverty

ERIC Educational Resources Information Center

Rosenbloom, Sandi

1970-01-01

Version of the paper given at The Transportation and Poverty Conference of the American Academy of Arts and Sciences. Argues for revival of jitneys (12-14 capacity motor vehicles, operating on fixed routes, fares zone-rated) to serve ghetto residents and provide employment, too. Taxi company competition also discussed. (KG)

Taxi-Out Time Prediction for Departures at Charlotte Airport Using Machine Learning Techniques

NASA Technical Reports Server (NTRS)

Lee, Hanbong; Malik, Waqar; Jung, Yoon C.

2016-01-01

Predicting the taxi-out times of departures accurately is important for improving airport efficiency and takeoff time predictability. In this paper, we attempt to apply machine learning techniques to actual traffic data at Charlotte Douglas International Airport for taxi-out time prediction. To find the key factors affecting aircraft taxi times, surface surveillance data is first analyzed. From this data analysis, several variables, including terminal concourse, spot, runway, departure fix and weight class, are selected for taxi time prediction. Then, various machine learning methods such as linear regression, support vector machines, k-nearest neighbors, random forest, and neural networks model are applied to actual flight data. Different traffic flow and weather conditions at Charlotte airport are also taken into account for more accurate prediction. The taxi-out time prediction results show that linear regression and random forest techniques can provide the most accurate prediction in terms of root-mean-square errors. We also discuss the operational complexity and uncertainties that make it difficult to predict the taxi times accurately.

Autonomous vehicles are cost-effective when used as taxis.

PubMed

Freedman, Isaac G; Kim, Ellen; Muennig, Peter A

2018-06-04

Autonomous vehicles (AVs) will radically re-shape the health and well-being of people in the United States in good ways and bad. We set out to estimate a reasonable time-to-adoption using cost-effectivenessmodels to estimate the point at which AVs become reasonably safe and affordable for widespread adoption. We used Waymo data (previously, Google Self-Driving Car Project) and a microsimulation model to explore projected costs and safety issues today and five years from today to get a sense of the speed of consumer adoption were AVs brought to the market. The adoption of AVs for private use was associated with an ICER of 1,396,110/QALY gained today, a figure that would decline to 173,890/QALY gained 5-years in the future. However, AV taxis are both less expensive and potentially already safer than human-piloted taxis. While AVs are not unlikely to be used a family vehicles any time soon, it would make economic sense to adopt them as taxis today. Legislation enhancing the benefits while mitigating the potential harmful health impacts of AV taxis is needed with some urgency.

Assessing and reducing fine and ultrafine particles inside Los Angeles taxis

NASA Astrophysics Data System (ADS)

Yu, Nu; Shu, Shi; Lin, Yan; Zhu, Yifang

2018-05-01

Taxi drivers and passengers are exposed to high levels of traffic-related air pollutants, but their exposures to fine (PM2.5) and ultrafine particles (UFPs) and related mitigation strategies are rarely explored. In this study, UFP and PM2.5 concentrations were monitored concurrently inside and outside of 22 taxis under different ventilation and mitigation conditions. Under realistic working conditions (no mitigation; NM), the average UFP and PM2.5 levels inside taxis were 1.46 × 104 particles/cm3 and 26 μg/m3, respectively. When the taxi ventilation was set to outside air mode and the windows kept closed, in-cabin UFP and PM2.5 concentrations are significantly associated with on-road concentrations, driving speed, and cabin air filter usage. The average in-cabin to on-roadway (I/O) ratios for UFP and PM2.5 were reduced from 0.60 to 0.75 under NM, to 0.47 and 0.52 under the most stringent mitigation strategy of keeping the windows closed and operating a high efficiency cabin air filter (WC + HECA). Among all tested taxi models, Toyota Prius exhibited the lowest UFP and PM2.5 I/O ratios under WC + HECA. Switching cabin air filters from the originally equipped manufacturer filter (OEM) to a HECA filter reduced the UFP and PM2.5 I/O ratios most effectively in Toyota Prius taxis as well.

DISPAQ: Distributed Profitable-Area Query from Big Taxi Trip Data.

PubMed

Putri, Fadhilah Kurnia; Song, Giltae; Kwon, Joonho; Rao, Praveen

2017-09-25

One of the crucial problems for taxi drivers is to efficiently locate passengers in order to increase profits. The rapid advancement and ubiquitous penetration of Internet of Things (IoT) technology into transportation industries enables us to provide taxi drivers with locations that have more potential passengers (more profitable areas) by analyzing and querying taxi trip data. In this paper, we propose a query processing system, called Distributed Profitable-Area Query ( DISPAQ ) which efficiently identifies profitable areas by exploiting the Apache Software Foundation's Spark framework and a MongoDB database. DISPAQ first maintains a profitable-area query index (PQ-index) by extracting area summaries and route summaries from raw taxi trip data. It then identifies candidate profitable areas by searching the PQ-index during query processing. Then, it exploits a Z-Skyline algorithm, which is an extension of skyline processing with a Z-order space filling curve, to quickly refine the candidate profitable areas. To improve the performance of distributed query processing, we also propose local Z-Skyline optimization, which reduces the number of dominant tests by distributing killer profitable areas to each cluster node. Through extensive evaluation with real datasets, we demonstrate that our DISPAQ system provides a scalable and efficient solution for processing profitable-area queries from huge amounts of big taxi trip data.

On Bipartite Graphs Trees and Their Partial Vertex Covers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caskurlu, Bugra; Mkrtchyan, Vahan; Parekh, Ojas D.

2015-03-01

Graphs can be used to model risk management in various systems. Particularly, Caskurlu et al. in [7] have considered a system, which has threats, vulnerabilities and assets, and which essentially represents a tripartite graph. The goal in this model is to reduce the risk in the system below a predefined risk threshold level. One can either restricting the permissions of the users, or encapsulating the system assets. The pointed out two strategies correspond to deleting minimum number of elements corresponding to vulnerabilities and assets, such that the flow between threats and assets is reduced below the predefined threshold level. Itmore » can be shown that the main goal in this risk management system can be formulated as a Partial Vertex Cover problem on bipartite graphs. It is well-known that the Vertex Cover problem is in P on bipartite graphs, however; the computational complexity of the Partial Vertex Cover problem on bipartite graphs has remained open. In this paper, we establish that the Partial Vertex Cover problem is NP-hard on bipartite graphs, which was also recently independently demonstrated [N. Apollonio and B. Simeone, Discrete Appl. Math., 165 (2014), pp. 37–48; G. Joret and A. Vetta, preprint, arXiv:1211.4853v1 [cs.DS], 2012]. We then identify interesting special cases of bipartite graphs, for which the Partial Vertex Cover problem, the closely related Budgeted Maximum Coverage problem, and their weighted extensions can be solved in polynomial time. We also present an 8/9-approximation algorithm for the Budgeted Maximum Coverage problem in the class of bipartite graphs. We show that this matches and resolves the integrality gap of the natural LP relaxation of the problem and improves upon a recent 4/5-approximation.« less

Airport Shared-Ride Taxi Programs in New York, Chicago and Boston

DOT National Transportation Integrated Search

1987-12-01

This report summarizes the development and operation of three shared-ride taxi operations at major U.S. airports. These are: New York's LaGuardia Airport Share-A-Cab; Super Saver Taxi in Chicago; and Share-A-Cab service at Boston's Logan Airport. The...

An evolving model of online bipartite networks

NASA Astrophysics Data System (ADS)

Zhang, Chu-Xu; Zhang, Zi-Ke; Liu, Chuang

2013-12-01

Understanding the structure and evolution of online bipartite networks is a significant task since they play a crucial role in various e-commerce services nowadays. Recently, various attempts have been tried to propose different models, resulting in either power-law or exponential degree distributions. However, many empirical results show that the user degree distribution actually follows a shifted power-law distribution, the so-called Mandelbrot’s law, which cannot be fully described by previous models. In this paper, we propose an evolving model, considering two different user behaviors: random and preferential attachment. Extensive empirical results on two real bipartite networks, Delicious and CiteULike, show that the theoretical model can well characterize the structure of real networks for both user and object degree distributions. In addition, we introduce a structural parameter p, to demonstrate that the hybrid user behavior leads to the shifted power-law degree distribution, and the region of power-law tail will increase with the increment of p. The proposed model might shed some lights in understanding the underlying laws governing the structure of real online bipartite networks.

Epidemic thresholds for bipartite networks

NASA Astrophysics Data System (ADS)

Hernández, D. G.; Risau-Gusman, S.

2013-11-01

It is well known that sexually transmitted diseases (STD) spread across a network of human sexual contacts. This network is most often bipartite, as most STD are transmitted between men and women. Even though network models in epidemiology have quite a long history now, there are few general results about bipartite networks. One of them is the simple dependence, predicted using the mean field approximation, between the epidemic threshold and the average and variance of the degree distribution of the network. Here we show that going beyond this approximation can lead to qualitatively different results that are supported by numerical simulations. One of the new features, that can be relevant for applications, is the existence of a critical value for the infectivity of each population, below which no epidemics can arise, regardless of the value of the infectivity of the other population.

Hematocrit levels as cardiovascular risk among taxi drivers in Bangkok, Thailand

PubMed Central

ISHIMARU, Tomohiro; ARPHORN, Sara; JIRAPONGSUWAN, Ann

2016-01-01

In Thailand, taxi drivers employed in the informal sector often experience hazardous working conditions. Previous studies revealed that elevated Hematocrit (HCT) is a predictor of cardiovascular disease (CVD) risk. This study assessed factors associated with HCT in taxi drivers to predict their occupational CVD risk factors. A cross-sectional study was conducted on 298 male taxi drivers who joined a health check-up campaign in Bangkok, Thailand. HCT and body mass index were retrieved from participant health check-up files. Self-administered questionnaires assessed demographics, driving mileage, working hours, and lifestyle. Statistical associations were analyzed using stepwise linear regression. Our results showed that obesity (p=0.007), daily alcohol drinking (p=0.003), and current or past smoking (p=0.016) were associated with higher HCT levels. While working hours were not directly associated with HCT levels in the current study, the effect on overworking is statistically arguable because most participants worked substantially longer hours. Our findings suggest that taxi drivers’ CVD risk may be increased by their unhealthy work styles. Initiatives to improve general working conditions for taxi drivers should take into account health promotion and CVD prevention. The policy of providing periodic health check-ups is important to make workers in the informal sector aware of their health status. PMID:27151439

Hematocrit levels as cardiovascular risk among taxi drivers in Bangkok, Thailand.

PubMed

Ishimaru, Tomohiro; Arphorn, Sara; Jirapongsuwan, Ann

2016-10-08

In Thailand, taxi drivers employed in the informal sector often experience hazardous working conditions. Previous studies revealed that elevated Hematocrit (HCT) is a predictor of cardiovascular disease (CVD) risk. This study assessed factors associated with HCT in taxi drivers to predict their occupational CVD risk factors. A cross-sectional study was conducted on 298 male taxi drivers who joined a health check-up campaign in Bangkok, Thailand. HCT and body mass index were retrieved from participant health check-up files. Self-administered questionnaires assessed demographics, driving mileage, working hours, and lifestyle. Statistical associations were analyzed using stepwise linear regression. Our results showed that obesity (p=0.007), daily alcohol drinking (p=0.003), and current or past smoking (p=0.016) were associated with higher HCT levels. While working hours were not directly associated with HCT levels in the current study, the effect on overworking is statistically arguable because most participants worked substantially longer hours. Our findings suggest that taxi drivers' CVD risk may be increased by their unhealthy work styles. Initiatives to improve general working conditions for taxi drivers should take into account health promotion and CVD prevention. The policy of providing periodic health check-ups is important to make workers in the informal sector aware of their health status.

14 CFR 298.21 - Filing for registration by air taxi operators.

Code of Federal Regulations, 2013 CFR

2013-01-01

... registration, the aircraft that it is currently operating in its air taxi operations, and the aircraft type, FAA registration number and passenger capacity of each aircraft; (vi) For initial registration, the... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Filing for registration by air taxi...

14 CFR 298.21 - Filing for registration by air taxi operators.

Code of Federal Regulations, 2012 CFR

2012-01-01

... registration, the aircraft that it is currently operating in its air taxi operations, and the aircraft type, FAA registration number and passenger capacity of each aircraft; (vi) For initial registration, the... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Filing for registration by air taxi...

14 CFR 298.21 - Filing for registration by air taxi operators.

Code of Federal Regulations, 2014 CFR

2014-01-01

... registration, the aircraft that it is currently operating in its air taxi operations, and the aircraft type, FAA registration number and passenger capacity of each aircraft; (vi) For initial registration, the... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Filing for registration by air taxi...

14 CFR 298.21 - Filing for registration by air taxi operators.

Code of Federal Regulations, 2011 CFR

2011-01-01

... registration, the aircraft that it is currently operating in its air taxi operations, and the aircraft type, FAA registration number and passenger capacity of each aircraft; (vi) For initial registration, the... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Filing for registration by air taxi...

Considering the effects of ambient particulate matter on the lung function of motorcycle taxi drivers in Bangkok, Thailand.

PubMed

Arphorn, Sara; Ishimaru, Tomohiro; Hara, Kunio; Mahasandana, Suwisa

2018-02-01

The motorcycle taxi drivers of Bangkok have been heavily exposed to high concentrations of PM 10 (particulate matter with an aerodynamic diameter ≤10 μm), and the impact of this on their lungs has been neither documented nor studied. This study examines the association between exposure to PM 10 and lung function decline among motorcycle taxi drivers. A cross-sectional study was conducted in Bangkok between two groups: a subject group of motorcycle taxi drivers and control group of enclosed vehicle taxi drivers. The findings of the Thailand Pollution Control Department were used to estimate the annual ambient PM 10 concentration levels in the metropolis. Pulmonary functions of motorcycle taxi drivers and enclosed vehicle taxi drivers were measured and compared using the Mann-Whitney test. Multiple linear regression analysis was applied to estimate the effects of PM 10 exposure on the lung function of motorcycle taxi drivers. A total of 1283 motorcycle taxi drivers and 600 taxi drivers were investigated. The mean forced expiratory volume in 1 sec/forced vital capacity (FEV 1 /FVC) of the motorcycle taxi drivers was significantly lower than that of the taxi drivers (P < 0.001). The mean FEV 1 /FVC of motorcycle taxi drivers exposed to ≥50 µg/m 3 PM 10 was statistically lower (-2.82%; 95% confidence interval [CI]: -4.54% to -1.09%) and the mean % vital capacity (%VC) of those exposed to 40-49.9 µg/m 3 PM 10 was statistically lower than that of motorcycle taxi drivers exposed to <30 µg/m 3 PM 10 (-3.33%; 95% CI: -5.79% to -0.87%). Motorcycle taxi drivers were directly exposed to air pollution in their working environment. As a result, their lung function might decrease more than that of enclosed vehicle taxi drivers. With the possible exposure to ≥50 µg/m 3 PM 10 , the vehicular emission standards should be vigorously enforced. Further investigation is warranted to clarify the effect of lung dysfunction on the work and lifestyle of motorcycle taxi

Exposure to particles and nitrogen dioxide among taxi, bus and lorry drivers.

PubMed

Lewné, Marie; Nise, Gun; Lind, Marie-Louise; Gustavsson, Per

2006-03-01

The aims of this study have been to investigate the occurrence of systematic differences in the personal exposure to motor exhaust between different groups of taxi, bus and lorry drivers, and to study if these are influenced by the choice of exposure indicator. We used one indicator of the gaseous phase, nitrogen dioxide (NO(2)), and one of the particle phase (measured by DataRAM), of the exhausts. A total of 121 drivers were included in the study: 39 taxi drivers, 42 bus drivers and 40 lorry drivers. Personal measurements were performed during one working day. Nitrogen dioxide was measured with passive diffusive samplers and particles with Data-RAM, a logging instrument using nephelometric monitoring. The instrument measures particles between 0.1 and 10 microm in size. The average exposure to NO(2) for lorry drivers was 68 microg/m(3); for bus drivers 60 microg/m(3) and for taxi drivers 48 microg/m(3). For particles the exposure was 57 microg/m(3) for lorry drivers, 44 microg/m(3) for bus drivers and 26 microg/m(3) for taxi drivers. The result remained unchanged when exposures were adjusted for variation in urban background levels of NO(2) and particulate matter with an aerodynamic diameter <10 microm (PM(10)). Lorry drivers experienced the highest exposure and taxi drivers the lowest with bus drivers in an intermediate position, regardless of whether NO(2) or particles were used as exposure indicator. The levels of both NO(2) and particles were higher for bus drivers in the city than for them driving in the suburbs. Using diesel or petrol as a fuel for taxis had no influence on the exposure for the drivers, indicating that the taxi drivers' exposure mainly depends on exhaust from surrounding traffic.

Driving fatigue in professional drivers: a survey of truck and taxi drivers.

PubMed

Meng, Fanxing; Li, Shuling; Cao, Lingzhi; Li, Musen; Peng, Qijia; Wang, Chunhui; Zhang, Wei

2015-01-01

Fatigue among truck drivers has been studied extensively; however, less is known regarding the fatigue experience of taxi drivers in heavily populated metropolitan areas. This study aimed to compare the differences and similarities between truck and taxi driver fatigue to provide implications for the fatigue management and education of professional drivers. A sample of 274 truck drivers and 286 taxi drivers in Beijing was surveyed via a questionnaire, which included items regarding work characteristics, fatigue experience, accident information, attitude toward fatigue, and methods of counteracting fatigue. Driver fatigue was prevalent among professional drivers, and it was even more serious for taxi drivers. Taxi drivers reported more frequent fatigue experiences and were involved in more accidents. Among the contributing factors to fatigue, prolonged driving time was the most important factor identified by both driver groups. Importantly, the reason for the engagement in prolonged driving was neither due to the lack of awareness concerning the serious outcome of fatigue driving nor because of their poor detection of fatigue. The most probable reason was the optimism bias, as a result of which these professional drivers thought that fatigue was more serious for other drivers than for themselves, and they thought that they were effective in counteracting the effect of fatigue on their driving performance. Moreover, truck drivers tended to employ methods that require stopping to counteract fatigue, whereas taxi drivers preferred methods that were simultaneous with driving. Although both driver groups considered taking a nap as one of the most effective means to address fatigue, this method was not commonly used. Interestingly, these drivers were aware that the methods they frequently used were not the most effective means to counteract fatigue. This study provides knowledge on truck and taxi drivers' characteristics in fatigue experience, fatigue attitude, and

Hybrid Taxis Give Fuel Economy a Lift, Clean Cities, Fleet Experiences, April 2009 (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2009-04-01

Clean Cities helped Boston, San Antonio, and Cambridge create hybrid taxi programs. The hybrid taxis are able to achieve about twice the gas mileage of a conventional taxi while helping cut gasoline use and fuel costs. Tax credits and other incentives are helping both company owners and drivers make the switch to hybrids. Program leaders have learned some important lessons other cities can benefit from including learning a city's taxi structure, relaying benefits to drivers, and understanding the needs of owners.

DISPAQ: Distributed Profitable-Area Query from Big Taxi Trip Data †

PubMed Central

Putri, Fadhilah Kurnia; Song, Giltae; Rao, Praveen

2017-01-01

One of the crucial problems for taxi drivers is to efficiently locate passengers in order to increase profits. The rapid advancement and ubiquitous penetration of Internet of Things (IoT) technology into transportation industries enables us to provide taxi drivers with locations that have more potential passengers (more profitable areas) by analyzing and querying taxi trip data. In this paper, we propose a query processing system, called Distributed Profitable-Area Query (DISPAQ) which efficiently identifies profitable areas by exploiting the Apache Software Foundation’s Spark framework and a MongoDB database. DISPAQ first maintains a profitable-area query index (PQ-index) by extracting area summaries and route summaries from raw taxi trip data. It then identifies candidate profitable areas by searching the PQ-index during query processing. Then, it exploits a Z-Skyline algorithm, which is an extension of skyline processing with a Z-order space filling curve, to quickly refine the candidate profitable areas. To improve the performance of distributed query processing, we also propose local Z-Skyline optimization, which reduces the number of dominant tests by distributing killer profitable areas to each cluster node. Through extensive evaluation with real datasets, we demonstrate that our DISPAQ system provides a scalable and efficient solution for processing profitable-area queries from huge amounts of big taxi trip data. PMID:28946679

Taxi Time Prediction at Charlotte Airport Using Fast-Time Simulation and Machine Learning Techniques

NASA Technical Reports Server (NTRS)

Lee, Hanbong

2016-01-01

Accurate taxi time prediction is required for enabling efficient runway scheduling that can increase runway throughput and reduce taxi times and fuel consumptions on the airport surface. Currently NASA and American Airlines are jointly developing a decision-support tool called Spot and Runway Departure Advisor (SARDA) that assists airport ramp controllers to make gate pushback decisions and improve the overall efficiency of airport surface traffic. In this presentation, we propose to use Linear Optimized Sequencing (LINOS), a discrete-event fast-time simulation tool, to predict taxi times and provide the estimates to the runway scheduler in real-time airport operations. To assess its prediction accuracy, we also introduce a data-driven analytical method using machine learning techniques. These two taxi time prediction methods are evaluated with actual taxi time data obtained from the SARDA human-in-the-loop (HITL) simulation for Charlotte Douglas International Airport (CLT) using various performance measurement metrics. Based on the taxi time prediction results, we also discuss how the prediction accuracy can be affected by the operational complexity at this airport and how we can improve the fast time simulation model before implementing it with an airport scheduling algorithm in a real-time environment.

Building versatile bipartite probes for quantum metrology

NASA Astrophysics Data System (ADS)

Farace, Alessandro; De Pasquale, Antonella; Adesso, Gerardo; Giovannetti, Vittorio

2016-01-01

We consider bipartite systems as versatile probes for the estimation of transformations acting locally on one of the subsystems. We investigate what resources are required for the probes to offer a guaranteed level of metrological performance, when the latter is averaged over specific sets of local transformations. We quantify such a performance via the average skew information (AvSk), a convex quantity which we compute in closed form for bipartite states of arbitrary dimensions, and which is shown to be strongly dependent on the degree of local purity of the probes. Our analysis contrasts and complements the recent series of studies focused on the minimum, rather than the average, performance of bipartite probes in local estimation tasks, which was instead determined by quantum correlations other than entanglement. We provide explicit prescriptions to characterize the most reliable states maximizing the AvSk, and elucidate the role of state purity, separability and correlations in the classification of optimal probes. Our results can help in the identification of useful resources for sensing, estimation and discrimination applications when complete knowledge of the interaction mechanism realizing the local transformation is unavailable, and access to pure entangled probes is technologically limited.

Nonconstant Positive Steady States and Pattern Formation of 1D Prey-Taxis Systems

NASA Astrophysics Data System (ADS)

Wang, Qi; Song, Yang; Shao, Lingjie

2017-02-01

Prey-taxis is the process that predators move preferentially toward patches with highest density of prey. It is well known to have an important role in biological control and the maintenance of biodiversity. To model the coexistence and spatial distributions of predator and prey species, this paper concerns nonconstant positive steady states of a wide class of prey-taxis systems with general functional responses over 1D domain. Linearized stability of the positive equilibrium is analyzed to show that prey-taxis destabilizes prey-predator homogeneity when prey repulsion (e.g., due to volume-filling effect in predator species or group defense in prey species) is present, and prey-taxis stabilizes the homogeneity otherwise. Then, we investigate the existence and stability of nonconstant positive steady states to the system through rigorous bifurcation analysis. Moreover, we provide detailed and thorough calculations to determine properties such as pitchfork and turning direction of the local branches. Our stability results also provide a stable wave mode selection mechanism for thee reaction-advection-diffusion systems including prey-taxis models considered in this paper. Finally, we provide numerical studies of prey-taxis systems with Holling-Tanner kinetics to illustrate and support our theoretical findings. Our numerical simulations demonstrate that the 2× 2 prey-taxis system is able to model the formation and evolution of various striking patterns, such as spikes, periodic oscillations, and coarsening even when the domain is one-dimensional. These dynamics can model the coexistence and spatial distributions of interacting prey and predator species. We also give some insights on how system parameters influence pattern formation in these models.

Driving to Better Health: Cancer and Cardiovascular Risk Assessment among Taxi Cab Operators in Chicago

PubMed Central

Apantaku-Onayemi, Funmi; Baldyga, William; Amuwo, Shaffdeen; Adefuye, Adedeji; Mason, Terry; Mitchell, Robin; Blumenthal, Daniel S.

2014-01-01

While a number of investigations of the health of taxi cab drivers have been conducted in Europe, Asia, and Africa, virtually none have been conducted in the United States. We undertook a survey of taxi cab operators in the Chicago area to understand better their health status and health promotion practices. The survey was completed by a convenience sample of 751 Chicago taxi drivers. Taxi drivers had low rates of insurance coverage, fruit and vegetable consumption, and physical activity compared with the general Chicago population. Participation in cancer screening tests was also lower for this group. A high proportion of taxi drivers are immigrants. They tend to be highly educated and report a readiness to engage in more health-promoting behaviors. Further research is needed to develop a targeted intervention for this population. PMID:22643623

Taxi Scrip Program in Seattle, Washington

DOT National Transportation Integrated Search

1982-09-01

The Municipality of Metropolitan Seattle (Metro) took over a taxi user-side subsidy program from the City of Seattle in December 1978, which was based on the sale of discounted taxicab scrip. Metro expanded the program, raised the discount, and condu...

Occupational health risks and intervention strategies for US taxi drivers.

PubMed

Murray, Kate E; Buul, Abdimalik; Aden, Rasheed; Cavanaugh, Alyson M; Kidane, Luwam; Hussein, Mikaiil; Eastman, Amelia; Checkoway, Harvey

2017-12-02

Research has shown that taxi drivers are at risk for numerous health concerns, such as low back and leg pain, linked to their highly sedentary occupation, long work hours and stressors related to the job (e.g. low income, safety threats). The goal of this study was to explore occupational health risks and opportunities for health interventions with taxi drivers using community-based participatory research (CBPR) methods. A mixed methods approach included first a convenience sample of 19 East African taxi drivers participating in focus group discussions. Second, a convenience sample of 75 current taxi drivers (M age = 45.7 years) and 25 non-driver comparison participants (M age = 40.3 years) were recruited to complete a structured self-reported questionnaire and objective measures of health. Health education was provided alongside the research to address common health concerns and to ensure mutual benefit and an action orientation. The focus groups described numerous health concerns that drivers attributed to their occupation, including chronic pain, sleep deprivation, cardiovascular disease, diabetes, kidney disease and eye problems, as the most common. Participants offered ideas for health interventions that include workplace reform and driver education. Quantitative data indicate that 44% of drivers reported their health as 'fair' or 'poor'. Drivers were more likely to report musculoskeletal pain, less sleep, more fatigue and less physical activity as compared to non-drivers. The majority of drivers reported financial and job dissatisfaction. The research provides data to inform targeted health interventions that support the health and safety of taxi drivers. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Unique patellofemoral alignment in a patient with a symptomatic bipartite patella.

PubMed

Ishikawa, Masakazu; Adachi, Nobuo; Deie, Masataka; Nakamae, Atsuo; Nakasa, Tomoyuki; Kamei, Goki; Takazawa, Kobun; Ochi, Mitsuo

2016-01-01

A symptomatic bipartite patella is rarely seen in athletic adolescents or young adults in daily clinical practice. To date, only a limited number of studies have focused on patellofemoral alignment. The current study revealed a unique patellofemoral alignment in a patient with a symptomatic bipartite patella. Twelve patients with 12 symptomatic bipartite patellae who underwent arthroscopic vastus lateralis release (VLR) were investigated (10 males and two females, age: 15.7±4.4years). The radiographic data of contralateral intact and affected knees were reviewed retrospectively. From the lateral- and skyline-view imaging, the following parameters were measured: the congruence angle (CA), the lateral patellofemoral angle (LPA), and the Caton-Deschamps index (CDI). As an additional parameter, the bipartite fragment angle (BFA) was evaluated against the main part of the patella in the skyline view. Compared with the contralateral side, the affected patellae were significantly medialized and laterally tilted (CA: P=0.019; LPA: P=0.016), although there was no significant difference in CDI (P=0.877). This patellar malalignment was found to significantly change after VLR (CA: P=0.001; LPA: P=0.003) and the patellar height was significantly lower than in the preoperative condition (P=0.016). In addition, the BFA significantly shifted to a higher degree after operation (P=0.001). Patients with symptomatic bipartite patellae presented significantly medialized and laterally tilted patellae compared with the contralateral intact side. This malalignment was corrected by VLR, and the alignment of the bipartite fragment was also significantly changed. Level IV, case series. Copyright © 2015 Elsevier B.V. All rights reserved.

[Occupational risk factors and perceptions of air pollution by motorcycle taxi drivers in Cotonou, Benin].

PubMed

Lawin, Hervé; Ayi Fanou, Lucie; Hinson, Vikkey; Tollo, Brice; Fayomi, Benjamin; Ouendo, Edgard-Marius

Motorcycle taxis occupy a major place in urban transport. Motorcycle taxi drivers are exposed to occupational risk factors (ORF) including air pollution. The objective of this study was to evaluate these ORF among motorcycle taxi drivers and their perceptions of air pollution. This mixed study was conducted on motorcycle taxi drivers in Cotonou. The qualitative study was based on focus groups concerning 16 items from the Participatory Occupational Risk Screening Guide (DEPARIS) until saturation and after triangulation of data. The quantitative study consisted of administering a questionnaire addressing socioeconomic and demographic characteristics, cardiopulmonary diseases, and perception of air -pollution risk factors among 397 Cotonou motorcycle taxi drivers. Drivers perceived poor road conditions, effort and handling, and lack of social security as unsatisfactory ORF. Their mean age was 40.95 ± 8.75 years and 45.84% had primary -education. They had been working as motorcycle taxi drivers for an average of 134.95 ± 101.53 months with an average income of FCFA 3138 ± 1238. These occupational factors were significantly associated with cardiopulmonary disorders, observed in 63.2% of drivers. Less than 1/3 of drivers felt that air pollution affected their personal health. Motorcycle taxi drivers have a poor perception of ORF and the severity of exposure to air pollution in this occupation. There is a need to take action to promote the health of this population.

Localization in random bipartite graphs: Numerical and empirical study

NASA Astrophysics Data System (ADS)

Slanina, František

2017-05-01

We investigate adjacency matrices of bipartite graphs with a power-law degree distribution. Motivation for this study is twofold: first, vibrational states in granular matter and jammed sphere packings; second, graphs encoding social interaction, especially electronic commerce. We establish the position of the mobility edge and show that it strongly depends on the power in the degree distribution and on the ratio of the sizes of the two parts of the bipartite graph. At the jamming threshold, where the two parts have the same size, localization vanishes. We found that the multifractal spectrum is nontrivial in the delocalized phase, but still near the mobility edge. We also study an empirical bipartite graph, namely, the Amazon reviewer-item network. We found that in this specific graph the mobility edge disappears, and we draw a conclusion from this fact regarding earlier empirical studies of the Amazon network.

Localization in random bipartite graphs: Numerical and empirical study.

PubMed

Slanina, František

2017-05-01

We investigate adjacency matrices of bipartite graphs with a power-law degree distribution. Motivation for this study is twofold: first, vibrational states in granular matter and jammed sphere packings; second, graphs encoding social interaction, especially electronic commerce. We establish the position of the mobility edge and show that it strongly depends on the power in the degree distribution and on the ratio of the sizes of the two parts of the bipartite graph. At the jamming threshold, where the two parts have the same size, localization vanishes. We found that the multifractal spectrum is nontrivial in the delocalized phase, but still near the mobility edge. We also study an empirical bipartite graph, namely, the Amazon reviewer-item network. We found that in this specific graph the mobility edge disappears, and we draw a conclusion from this fact regarding earlier empirical studies of the Amazon network.

A bipartite fitness model for online music streaming services

NASA Astrophysics Data System (ADS)

Pongnumkul, Suchit; Motohashi, Kazuyuki

2018-01-01

This paper proposes an evolution model and an analysis of the behavior of music consumers on online music streaming services. While previous studies have observed power-law degree distributions of usage in online music streaming services, the underlying behavior of users has not been well understood. Users and songs can be described using a bipartite network where an edge exists between a user node and a song node when the user has listened that song. The growth mechanism of bipartite networks has been used to understand the evolution of online bipartite networks Zhang et al. (2013). Existing bipartite models are based on a preferential attachment mechanism László Barabási and Albert (1999) in which the probability that a user listens to a song is proportional to its current popularity. This mechanism does not allow for two types of real world phenomena. First, a newly released song with high quality sometimes quickly gains popularity. Second, the popularity of songs normally decreases as time goes by. Therefore, this paper proposes a new model that is more suitable for online music services by adding fitness and aging functions to the song nodes of the bipartite network proposed by Zhang et al. (2013). Theoretical analyses are performed for the degree distribution of songs. Empirical data from an online streaming service, Last.fm, are used to confirm the degree distribution of the object nodes. Simulation results show improvements from a previous model. Finally, to illustrate the application of the proposed model, a simplified royalty cost model for online music services is used to demonstrate how the changes in the proposed parameters can affect the costs for online music streaming providers. Managerial implications are also discussed.

National Ridesharing Demonstration Program : `Maxi-Taxi' Services in the Tidewater Region of Virginia

DOT National Transportation Integrated Search

1985-07-01

In November 1980, the Tidewater Regional Transit Authority (TRT) Implemented a series of shared-ride taxi services under the program name "Maxi-Taxi" (name which was subsequently changed to Maxi-Ride to avert legal challenges). These services, suppli...

Respiratory symptoms and lung function in garage workers and taxi drivers.

PubMed

Bener, A; Galadari, I; al-Mutawa, J K; al-Maskari, F; Das, M; Abuzeid, M S

1998-12-01

The aim of this study was to determine the prevalence of some respiratory symptoms and possible diseases among occupationally-exposed garage workers and taxi drivers. This study involved 158 garage workers and 165 taxi drivers, matched for age, sex, nationality and duration of employment. The mean age of 158 Indian subcontinent garage workers was 34.4 +/- 10.4 years; their mean height and weight were 167.7 +/- 6.6 cm and 72.0 +/- 12.3 kg respectively, and the mean duration of employment garage workers was 8.8 +/- 7.6 years. The mean age of 165 Indian subcontinent male taxi drivers was 34.5 +/- 7.7 years; their mean height and weight were 168.7 +/- 6.1 cm and 71.3 +/- 12.6 kg respectively; and the mean duration of employment was 7.5 +/- 5.4 years. The data on chronic respiratory symptoms showed that garage workers had higher prevalence of symptoms than taxi drivers being significantly greater for chronic phlegm, (p < 0.007); dyspneoa (p < 0.001); and sinusitis (p < 0.03). A higher prevalence of all acute symptoms was recorded in garage workers than in taxi drivers, although the differences were significant only for throat (p < 0.02), hearing problems (p < 0.002); nose (dryness, bleeding and secretion) (p < 0.008); and low back pain (p < 0.05). Almost all forced spirometric tests in the exposed garage workers were lower than in taxi drivers. The results of stepwise multiple regression analysis showed that only phlegm, sinusitis, hearing problems, nasal catarrh, throat, low back pain, smoking and FEF25-75, variables were statistically significant predictors as risk factors. In conclusion, the present study suggests that a high prevalence of respiratory symptoms is associated with exposure to motor vehicle exhaust emission in garage working places. Long-term working as garage workers in the United Arab Emirates (UAE), may be associated with the development of chronic respiratory symptoms and have effects on their daily life and health.

A fast community detection method in bipartite networks by distance dynamics

NASA Astrophysics Data System (ADS)

Sun, Hong-liang; Ch'ng, Eugene; Yong, Xi; Garibaldi, Jonathan M.; See, Simon; Chen, Duan-bing

2018-04-01

Many real bipartite networks are found to be divided into two-mode communities. In this paper, we formulate a new two-mode community detection algorithm BiAttractor. It is based on distance dynamics model Attractor proposed by Shao et al. with extension from unipartite to bipartite networks. Since Jaccard coefficient of distance dynamics model is incapable to measure distances of different types of vertices in bipartite networks, our main contribution is to extend distance dynamics model from unipartite to bipartite networks using a novel measure Local Jaccard Distance (LJD). Furthermore, distances between different types of vertices are not affected by common neighbors in the original method. This new idea makes clear assumptions and yields interpretable results in linear time complexity O(| E |) in sparse networks, where | E | is the number of edges. Experiments on synthetic networks demonstrate it is capable to overcome resolution limit compared with existing other methods. Further research on real networks shows that this model can accurately detect interpretable community structures in a short time.

Shared-Ride Taxi Service in Boston, MA

DOT National Transportation Integrated Search

1985-03-01

This report presents an evaluation of the Boston Shared-Ride Taxi Demonstration. The City of Boston's Traffic and Parking Department, the project grantee, designed a shared-ride service for Boston's Allston-Brighton neighborhood; Boston Cab Associati...

Filters from taxis air conditioning system: A tool to characterize driver's occupational exposure to bioburden?

PubMed

Viegas, Carla; Monteiro, Ana; Dos Santos, Mateus; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Quintal Gomes, Anita; Marchand, Geneviève; Lacombe, Nancy; Viegas, Susana

2018-07-01

Bioburden proliferation in filters from air conditioning systems of taxis represents a possible source of occupational exposure. The aim of this study was to determine the occurrence of fungi and bacteria in filters from the air conditioning system of taxis used for patient transportation and to assess the exposure of drivers to bioburden. Filters from the air conditioning systems of 19 taxis and 28 personal vehicles (used as controls) operating in three Portuguese cities including the capital Lisbon, were collected during the winter season. The occurrence and significance of bioburden detected in the different vehicles are reported and discussed in terms of colony-forming units (CFU) per 1 m 2 of filter area and by the identification of the most frequently detected fungal isolates based on morphology. Azole-resistant mycobiota, fungal biomass, and molecular detection of Aspergillus species/strains were also determined. Bacterial growth was more prevalent in taxis (63.2%) than in personal vehicles (26.3%), whereas fungal growth was more prevalent in personal vehicles (53.6%) than in taxis (21.1-31.6%). Seven different azole-resistant species were identified in this study in 42.1% taxi filters. Levels of fungal biomass were above the detection limit in 63% taxi filters and in 75% personal vehicle filters. No toxigenic species were detected by molecular analysis in the assessed filters. The results obtained show that bioburden proliferation occurs widely in filters from the air conditioning systems of taxis, including the proliferation of azole-resistant fungal species, suggesting that filters should be replaced more frequently. The use of culture based-methods and molecular tools combined enabled an improved risk characterization in this setting. Copyright © 2018 Elsevier Inc. All rights reserved.

Math on the Job. Taxi Driver.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus. National Center for Research in Vocational Education.

This booklet is intended to help mainstreamed mentally retarded, emotionally disturbed, or learning disabled high school students acquire a basic understanding of the responsibilities and working conditions of taxi drivers and to practice basic math skills necessary in the occupation. The first section provides a brief introduction to the…

Randomizing bipartite networks: the case of the World Trade Web.

PubMed

Saracco, Fabio; Di Clemente, Riccardo; Gabrielli, Andrea; Squartini, Tiziano

2015-06-01

Within the last fifteen years, network theory has been successfully applied both to natural sciences and to socioeconomic disciplines. In particular, bipartite networks have been recognized to provide a particularly insightful representation of many systems, ranging from mutualistic networks in ecology to trade networks in economy, whence the need of a pattern detection-oriented analysis in order to identify statistically-significant structural properties. Such an analysis rests upon the definition of suitable null models, i.e. upon the choice of the portion of network structure to be preserved while randomizing everything else. However, quite surprisingly, little work has been done so far to define null models for real bipartite networks. The aim of the present work is to fill this gap, extending a recently-proposed method to randomize monopartite networks to bipartite networks. While the proposed formalism is perfectly general, we apply our method to the binary, undirected, bipartite representation of the World Trade Web, comparing the observed values of a number of structural quantities of interest with the expected ones, calculated via our randomization procedure. Interestingly, the behavior of the World Trade Web in this new representation is strongly different from the monopartite analogue, showing highly non-trivial patterns of self-organization.

Common neighbours and the local-community-paradigm for topological link prediction in bipartite networks

NASA Astrophysics Data System (ADS)

Daminelli, Simone; Thomas, Josephine Maria; Durán, Claudio; Vittorio Cannistraci, Carlo

2015-11-01

Bipartite networks are powerful descriptions of complex systems characterized by two different classes of nodes and connections allowed only across but not within the two classes. Unveiling physical principles, building theories and suggesting physical models to predict bipartite links such as product-consumer connections in recommendation systems or drug-target interactions in molecular networks can provide priceless information to improve e-commerce or to accelerate pharmaceutical research. The prediction of nonobserved connections starting from those already present in the topology of a network is known as the link-prediction problem. It represents an important subject both in many-body interaction theory in physics and in new algorithms for applied tools in computer science. The rationale is that the existing connectivity structure of a network can suggest where new connections can appear with higher likelihood in an evolving network, or where nonobserved connections are missing in a partially known network. Surprisingly, current complex network theory presents a theoretical bottle-neck: a general framework for local-based link prediction directly in the bipartite domain is missing. Here, we overcome this theoretical obstacle and present a formal definition of common neighbour index and local-community-paradigm (LCP) for bipartite networks. As a consequence, we are able to introduce the first node-neighbourhood-based and LCP-based models for topological link prediction that utilize the bipartite domain. We performed link prediction evaluations in several networks of different size and of disparate origin, including technological, social and biological systems. Our models significantly improve topological prediction in many bipartite networks because they exploit local physical driving-forces that participate in the formation and organization of many real-world bipartite networks. Furthermore, we present a local-based formalism that allows to intuitively

A Collaborative Recommend Algorithm Based on Bipartite Community

PubMed Central

Fu, Yuchen; Liu, Quan; Cui, Zhiming

2014-01-01

The recommendation algorithm based on bipartite network is superior to traditional methods on accuracy and diversity, which proves that considering the network topology of recommendation systems could help us to improve recommendation results. However, existing algorithms mainly focus on the overall topology structure and those local characteristics could also play an important role in collaborative recommend processing. Therefore, on account of data characteristics and application requirements of collaborative recommend systems, we proposed a link community partitioning algorithm based on the label propagation and a collaborative recommendation algorithm based on the bipartite community. Then we designed numerical experiments to verify the algorithm validity under benchmark and real database. PMID:24955393

Prevalence and factors associated with road traffic crash among taxi drivers in Hanoi, Vietnam.

PubMed

La, Quang Ngoc; Lee, Andy H; Meuleners, Lynn B; Van Duong, Dat

2013-01-01

Injury due to road traffic crash is a major cause of ill health and premature deaths in developing countries. Taxis provide a main mode of public transport in Vietnam but there has been little research on the risk of crash for taxi drivers. This retrospective study collected information on taxi crashes for the period 2006-2009 by interviewing drivers from five taxi companies in Hanoi, Vietnam, using a structured questionnaire. Of the total 1214 participants recruited, 276 drivers reported at least one crash, giving an overall crash prevalence of 22.7%. Among the crashed group, 50 drivers (18.1%) were involved in two to four crashes. Logistic regression analysis further identified age of driver, type of driving licence, employment status, perceived sufficiency of income, seat-belt usage, and traffic infringement history to be significantly associated with the crash risk. Further prospective and qualitative studies are recommended to provide detailed crash characteristics as well as behaviour and perception of taxi drivers, so that an effective intervention can be developed to improve road safety and to prevent injury of these commercial drivers. Copyright © 2012 Elsevier Ltd. All rights reserved.

76 FR 33639 - Safety Zone; New York Water Taxi 10th Anniversary Fireworks

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-09

...-AA00 Safety Zone; New York Water Taxi 10th Anniversary Fireworks, Upper New York Bay, Red Hook, NY... New York Water Taxi. The fireworks will commence at 9 p.m. on June 21, 2011 and will last... CFR Part 165 Harbors, Marine safety, Navigation (water), Reporting and recordkeeping requirements...

The management of the painful bipartite patella: a systematic review.

PubMed

McMahon, Samuel E; LeRoux, Johannes A; Smith, Toby O; Hing, Caroline B

2016-09-01

This study aimed to identify the most effective method for the treatment of the symptomatic bipartite patella. A systematic review of the literature was completed, and all studies assessing the management of a bipartite patella were included. Owing to the paucity of randomised controlled trials, a narrative review of 22 studies was completed. A range of treatments were assessed: conservative measures, open and arthroscopic fixation or excision and soft tissue release and excision. All of the methods provided results ranging from good to excellent, with acceptable complication rates. This is a poorly answered treatment question. No firm guidance can be given as to the most appropriate method of treating the symptomatic bipartite patella. This study suggests that there are a number of effective treatments with acceptable complication rates and it may be that treatments that conserve the patella are more appropriate for larger fragments. IV.

Forensic Identification of Bipartite Patella Misdiagnosed as Patella Fracture.

PubMed

Ma, Jingyuan; Shi, Fang; Huang, Chongya; Gu, Shanzhi

2017-07-01

Bipartite patella is recognized as a developmental anomaly of ossification. Most of them are asymptomatic and are discovered incidentally. Bipartite patella is sometimes misdiagnosed as a patella fracture, because the x-ray images of both these conditions may appear very similar. In this case, the patient complained of left knee pain after x-ray films revealed a fracture-like line in the left patella. The patient was then diagnosed as having a patella fracture. In China, the injury degree is categorized as serious injury, minor injury, and trivial injury. As the injury degree of patellar fracture is identified as minor injury, the defendant who injured the patient will be sentenced to prison for ≤3 years. However, the defendant objected to this judgment and applied for the second evaluation of injury degree. On the basis of the site of injury, clinical manifestations, and imaging findings, we diagnosed the patient with bipartite patella which belongs to normal anatomic variant. Therefore, the injury degree of the patient was not minor injury. © 2017 American Academy of Forensic Sciences.

Grand canonical validation of the bipartite international trade network.

PubMed

Straka, Mika J; Caldarelli, Guido; Saracco, Fabio

2017-08-01

Devising strategies for economic development in a globally competitive landscape requires a solid and unbiased understanding of countries' technological advancements and similarities among export products. Both can be addressed through the bipartite representation of the International Trade Network. In this paper, we apply the recently proposed grand canonical projection algorithm to uncover country and product communities. Contrary to past endeavors, our methodology, based on information theory, creates monopartite projections in an unbiased and analytically tractable way. Single links between countries or products represent statistically significant signals, which are not accounted for by null models such as the bipartite configuration model. We find stable country communities reflecting the socioeconomic distinction in developed, newly industrialized, and developing countries. Furthermore, we observe product clusters based on the aforementioned country groups. Our analysis reveals the existence of a complicated structure in the bipartite International Trade Network: apart from the diversification of export baskets from the most basic to the most exclusive products, we observe a statistically significant signal of an export specialization mechanism towards more sophisticated products.

Grand canonical validation of the bipartite international trade network

NASA Astrophysics Data System (ADS)

Straka, Mika J.; Caldarelli, Guido; Saracco, Fabio

2017-08-01

Devising strategies for economic development in a globally competitive landscape requires a solid and unbiased understanding of countries' technological advancements and similarities among export products. Both can be addressed through the bipartite representation of the International Trade Network. In this paper, we apply the recently proposed grand canonical projection algorithm to uncover country and product communities. Contrary to past endeavors, our methodology, based on information theory, creates monopartite projections in an unbiased and analytically tractable way. Single links between countries or products represent statistically significant signals, which are not accounted for by null models such as the bipartite configuration model. We find stable country communities reflecting the socioeconomic distinction in developed, newly industrialized, and developing countries. Furthermore, we observe product clusters based on the aforementioned country groups. Our analysis reveals the existence of a complicated structure in the bipartite International Trade Network: apart from the diversification of export baskets from the most basic to the most exclusive products, we observe a statistically significant signal of an export specialization mechanism towards more sophisticated products.

BIPAD: A web server for modeling bipartite sequence elements

PubMed Central

Bi, Chengpeng; Rogan, Peter K

2006-01-01

Background Many dimeric protein complexes bind cooperatively to families of bipartite nucleic acid sequence elements, which consist of pairs of conserved half-site sequences separated by intervening distances that vary among individual sites. Results We introduce the Bipad Server [1], a web interface to predict sequence elements embedded within unaligned sequences. Either a bipartite model, consisting of a pair of one-block position weight matrices (PWM's) with a gap distribution, or a single PWM matrix for contiguous single block motifs may be produced. The Bipad program performs multiple local alignment by entropy minimization and cyclic refinement using a stochastic greedy search strategy. The best models are refined by maximizing incremental information contents among a set of potential models with varying half site and gap lengths. Conclusion The web service generates information positional weight matrices, identifies binding site motifs, graphically represents the set of discovered elements as a sequence logo, and depicts the gap distribution as a histogram. Server performance was evaluated by generating a collection of bipartite models for distinct DNA binding proteins. PMID:16503993

Toward edge minability for role mining in bipartite networks

NASA Astrophysics Data System (ADS)

Dong, Lijun; Wang, Yi; Liu, Ran; Pi, Benjie; Wu, Liuyi

2016-11-01

Bipartite network models have been extensively used in information security to automatically generate role-based access control (RBAC) from dataset. This process is called role mining. However, not all the topologies of bipartite networks are suitable for role mining; some edges may even reduce the quality of role mining. This causes unnecessary time consumption as role mining is NP-hard. Therefore, to promote the quality of role mining results, the capability that an edge composes roles with other edges, called the minability of edge, needs to be identified. We tackle the problem from an angle of edge importance in complex networks; that is an edge easily covered by roles is considered to be more important. Based on this idea, the k-shell decomposition of complex networks is extended to reveal the different minability of edges. By this way, a bipartite network can be quickly purified by excluding the low-minability edges from role mining, and thus the quality of role mining can be effectively improved. Extensive experiments via the real-world datasets are conducted to confirm the above claims.

On-road emission characteristics of CNG-fueled bi-fuel taxis

NASA Astrophysics Data System (ADS)

Yao, Zhiliang; Cao, Xinyue; Shen, Xianbao; Zhang, Yingzhi; Wang, Xintong; He, Kebin

2014-09-01

To alleviate air pollution and lessen the petroleum demand from the motor vehicle sector in China, natural gas vehicles (NGVs) have been rapidly developed over the last several years. However, the understanding of the real-world emissions of NGVs is very limited. In this study, the emissions from 20 compressed-natural-gas-fueled bi-fuel taxis were measured using a portable emission measurement system (PEMS) under actual driving conditions in Yichang, China. The emission characteristics of the tested vehicles were analyzed, revealing that the average CO2, CO, HC and NOx emissions from the tested compressed-natural-gas (CNG) taxis under urban driving conditions were 1.6, 4.0, 2.0 and 0.98 times those under highway road conditions, respectively. The CO, HC and NOx emissions from Euro 3 CNG vehicles were approximately 40%, 55% and 44% lower than those from Euro 2 vehicles, respectively. Compared with the values for light-duty gasoline vehicles reported in the literature, the CO2 and CO emissions from the tested CNG taxis were clearly lower; however, significant increases in the HC and NOx emissions were observed. Finally, we normalized the emissions under the actual driving cycles of the entire test route to the New European Driving Cycle (NEDC)-based emissions using a VSP modes method developed by North Carolina State University. The simulated NEDC-based CO emissions from the tested CNG taxis were better than the corresponding emissions standards, whereas the simulated NEDC-based HC and NOx emissions greatly exceeded the standards. Thus, more attention should be paid to the emissions from CNG vehicles. As for the CNG-fueled bi-fuel taxis currently in use, the department of environmental protection should strengthen their inspection and supervision to reduce the emissions from these vehicles. The results of this study will be helpful in understanding and controlling emissions from CNG-fueled bi-fuel vehicles in China.

Comment on "Protecting bipartite entanglement by quantum interferences"

NASA Astrophysics Data System (ADS)

Nair, Anjali N.; Arun, R.

2018-03-01

In an interesting article [Phys. Rev. A 81, 052341 (2010), 10.1103/PhysRevA.81.052341], Das and Agarwal have discussed the preservation of bipartite entanglement in three-level atoms employing the coherences induced by spontaneous emission. The authors considered various initially entangled qubits prepared from two V -type three-level atoms and showed that more than 50 % of the initial (bipartite) entanglement can be preserved in steady state due to vacuum-induced coherence. In this Comment, we point out that their analytical formulas for the entanglement measure contain errors affecting all the numerical results of that article. We substantiate our claim by giving correct analytical results for the time evolution of the two-atom system.

14 CFR Appendix C to Part 330 - Forms for Air Taxi Operators

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Forms for Air Taxi Operators C Appendix C to Part 330 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION... Part 330—Forms for Air Taxi Operators ER20AU02.009 ER20AU02.010 ER20AU02.011 ER20AU02.012 ER20AU02.013...

Return to activity among athletes with a symptomatic bipartite patella: a systematic review.

PubMed

Matic, George T; Flanigan, David C

2015-09-01

A bipartite patella is typically rare, but can become symptomatic during overuse activities such as those performed during athletic events. Therefore, this anomaly typically presents in the young, athletic population, often inhibiting athletic activities. Multiple treatment options exist, with nonsurgical management frequently adopted as the initial treatment of choice. To determine the most effective intervention in returning athletes with symptomatic bipartite patella to their prior activity levels. A systematic review of the literature was performed using PRISMA guidelines to identify studies reporting outcomes of athletes' ability to return to activity following treatment for a symptomatic bipartite patella. The type of intervention, type of bipartite classification, outcomes, and complications were recorded. Twenty articles with a total of 125 patients and 130 knees were identified and included in this review. A total of 105 athletes made a full return to athletic activity following treatment for their painful bipartite patella. One hundred athletes (85.5%) that underwent surgical treatment were able to make a full return to their sport without symptoms, although this varied by surgical procedure performed. Excision of the painful fragment produced the best results in returning athletes to sport, with 91% returning without symptoms and nine percent returning but with residual symptoms. Surgical treatments for symptomatic bipartite patellae are successful at returning athletes to their same level of play, and best outcomes are with excision of the fragment. These results are limited, however, due to the poor quality of original data given the rarity of the anomaly and the underrepresented conservative treatment group. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of the bipartite structure of a network on performance of recommenders

NASA Astrophysics Data System (ADS)

Wang, Qing-Xian; Li, Jian; Luo, Xin; Xu, Jian-Jun; Shang, Ming-Sheng

2018-02-01

Recommender systems aim to predict people's preferences for online items by analyzing their historical behaviors. A recommender can be modeled as a high-dimensional and sparse bipartite network, where the key issue is to understand the relation between the network structure and a recommender's performance. To address this issue, we choose three network characteristics, clustering coefficient, network density and user-item ratio, as the analyzing targets. For the cluster coefficient, we adopt the Degree-preserving rewiring algorithm to obtain a series of bipartite network with varying cluster coefficient, while the degree of user and item keep unchanged. Furthermore, five state-of-the-art recommenders are applied on two real datasets. The performances of recommenders are measured by both numerical and physical metrics. These results show that a recommender's performance is positively related to the clustering coefficient of a bipartite network. Meanwhile, higher density of a bipartite network can provide more accurate but less diverse or novel recommendations. Furthermore, the user-item ratio is positively correlated with the accuracy metrics but negatively correlated with the diverse and novel metrics.

Two classes of bipartite networks: nested biological and social systems.

PubMed

Burgos, Enrique; Ceva, Horacio; Hernández, Laura; Perazzo, R P J; Devoto, Mariano; Medan, Diego

2008-10-01

Bipartite graphs have received some attention in the study of social networks and of biological mutualistic systems. A generalization of a previous model is presented, that evolves the topology of the graph in order to optimally account for a given contact preference rule between the two guilds of the network. As a result, social and biological graphs are classified as belonging to two clearly different classes. Projected graphs, linking the agents of only one guild, are obtained from the original bipartite graph. The corresponding evolution of its statistical properties is also studied. An example of a biological mutualistic network is analyzed in detail, and it is found that the model provides a very good fitting of all the main statistical features. The model also provides a proper qualitative description of the same features observed in social webs, suggesting the possible reasons underlying the difference in the organization of these two kinds of bipartite networks.

Monopoly Profits: The Market for Taxi Licenses.

ERIC Educational Resources Information Center

Keane, Michael

1981-01-01

Presents a case study dealing with open versus closed markets for use in college economics classes. Using the example of the taxi license monopoly in Dublin, Ireland, students examine how theories of supply and demand explain the characteristics of open and closed markets. (AM)

[Association between psychosocial aspects of work and quality of life among motorcycle taxi drivers].

PubMed

Teixeira, Jules Ramon Brito; Boery, Eduardo Nagib; Casotti, Cezar Augusto; Araújo, Tânia Maria de; Pereira, Rafael; Ribeiro, Ícaro José Santos; Rios, Marcela Andrade; Amorim, Camila Rego; Moreira, Ramon Missias; Boery, Rita Narriman Silva de Oliveira; Sales, Zenilda Nogueira

2015-01-01

This study aimed to evaluate the quality of life of motorcycle taxi drivers and the association with psychosocial characteristics of their work. This was a cross-sectional epidemiological study with a sample of 400 motorcycle taxi drivers in Jequié, Bahia State, Brazil. The study used a form containing demographic and socioeconomic data, WHO Quality of Life-Bref Questionnaire (WHOQOL-Bref), and the Job Content Questionnaire (JCQ). Motorcycle taxi drivers with greater decision-making control over their work showed better self-rated quality of life in the psychological domain; those with high psychological demands presented better self-rated quality of life in the social relations and environmental domains; those with high strain and active work showed better self-rated quality of life in the social and environmental domains. The psychosocial work environment and especially decision-making autonomy were thus important determinants of self-rated quality of life in this group of motorcycle taxi drivers.

On bipartite pure-state entanglement structure in terms of disentanglement

NASA Astrophysics Data System (ADS)

Herbut, Fedor

2006-12-01

Schrödinger's disentanglement [E. Schrödinger, Proc. Cambridge Philos. Soc. 31, 555 (1935)], i.e., remote state decomposition, as a physical way to study entanglement, is carried one step further with respect to previous work in investigating the qualitative side of entanglement in any bipartite state vector. Remote measurement (or, equivalently, remote orthogonal state decomposition) from previous work is generalized to remote linearly independent complete state decomposition both in the nonselective and the selective versions. The results are displayed in terms of commutative square diagrams, which show the power and beauty of the physical meaning of the (antiunitary) correlation operator inherent in the given bipartite state vector. This operator, together with the subsystem states (reduced density operators), constitutes the so-called correlated subsystem picture. It is the central part of the antilinear representation of a bipartite state vector, and it is a kind of core of its entanglement structure. The generalization of previously elaborated disentanglement expounded in this article is a synthesis of the antilinear representation of bipartite state vectors, which is reviewed, and the relevant results of [Cassinelli et al., J. Math. Anal. Appl. 210, 472 (1997)] in mathematical analysis, which are summed up. Linearly independent bases (finite or infinite) are shown to be almost as useful in some quantum mechanical studies as orthonormal ones. Finally, it is shown that linearly independent remote pure-state preparation carries the highest probability of occurrence. This singles out linearly independent remote influence from all possible ones.

Terminal area automatic navigation, guidance, and control 1: Automatic rollout, turnoff, and taxis

NASA Technical Reports Server (NTRS)

Pines, S.

1981-01-01

A study developed for the TCV B-737, designed to apply existing navigation aids plus magnetic leader cable signals and develop breaking and reverse thrust guidance laws to provide for rapid automated rollout, turnoff, and taxi to reduce runway occupation time for a wide variety of landing conditions for conventional commercial-type aircraft, is described. Closed loop guidance laws for braking and reverse thrust are derived for rollout, turnoff, and taxi, as functions of the landing speed, the desired taxi speed and the distance to go. Brake limitations for wet runway conditions and reverse thrust limitations are taken into account to provide decision rules to avoid tire skid and to choose an alternate turnoff point, farther down the runway, to accommodate extreme landing conditions.

Shared Ride Taxi Feeder Service in Memphis, TN

DOT National Transportation Integrated Search

1988-03-01

From May 1983 through October 1984, the Memphis Area Transit Authority (MATA) conducted the Taxi Feeder Demonstration Project. It entailed the operation of fixed-route feeder services through three low-density neighborhoods and one industrial park, c...

The relation between working conditions, aberrant driving behaviour and crash propensity among taxi drivers in China.

PubMed

Wang, Yonggang; Li, Linchao; Prato, Carlo G

2018-04-03

Although the taxi industry is playing an important role in Chinese everyday life, little attention has been posed towards occupational health issues concerning the taxi drivers' working conditions, driving behaviour and road safety. A cross-sectional survey was administered to 1021 taxi drivers from 21 companies in four Chinese cities and collected information about (i) sociodemographic characteristics, (ii) working conditions, (iii) frequency of daily aberrant driving behaviour, and (iv) involvement in property-damage-only (PDO) and personal injury (PI) crashes over the past two years. A hybrid bivariate model of crash involvement was specified: (i) the hybrid part concerned a latent variable model capturing unobserved traits of the taxi drivers; (ii) the bivariate part modelled jointly both types of crashes while capturing unobserved correlation between error terms. The survey answers paint a gloomy picture in terms of workload, as taxi drivers reported averages of 9.4 working hours per day and 6.7 working days per week that amount on average to about 63.0 working hours per week. Moreover, the estimates of the hybrid bivariate model reveal that increasing levels of fatigue, reckless behaviour and aggressive behaviour are positively related to a higher propensity of crash involvement. Lastly, the heavy workload is also positively correlated with the higher propensity of crashing, not only directly as a predictor of crash involvement, but also indirectly as a covariate of fatigue and aberrant driving behaviour. The findings from this study provide insights into potential strategies for preventive education and taxi industry management to improve the working conditions and hence reduce fatigue and road risk for the taxi drivers. Copyright © 2018 Elsevier Ltd. All rights reserved.

Shared-Ride Taxi Computer Control System Requirements Study

DOT National Transportation Integrated Search

1977-08-01

The technical problem of scheduling and routing shared-ride taxi service is so great that only computers can handle it efficiently. This study is concerned with defining the requirements of such a computer system. The major objective of this study is...

Constitutive expression of the xylanase inhibitor TAXI-III delays Fusarium head blight symptoms in durum wheat transgenic plants.

PubMed

Moscetti, Ilaria; Tundo, Silvio; Janni, Michela; Sella, Luca; Gazzetti, Katia; Tauzin, Alexandra; Giardina, Thierry; Masci, Stefania; Favaron, Francesco; D'Ovidio, Renato

2013-12-01

Cereals contain xylanase inhibitor (XI) proteins which inhibit microbial xylanases and are considered part of the defense mechanisms to counteract microbial pathogens. Nevertheless, in planta evidence for this role has not been reported yet. Therefore, we produced a number of transgenic plants constitutively overexpressing TAXI-III, a member of the TAXI type XI that is induced by pathogen infection. Results showed that TAXI-III endows the transgenic wheat with new inhibition capacities. We also showed that TAXI-III is correctly secreted into the apoplast and possesses the expected inhibition parameters against microbial xylanases. The new inhibition properties of the transgenic plants correlate with a significant delay of Fusarium head blight disease symptoms caused by Fusarium graminearum but do not significantly influence leaf spot symptoms caused by Bipolaris sorokiniana. We showed that this contrasting result can be due to the different capacity of TAXI-III to inhibit the xylanase activity of these two fungal pathogens. These results provide, for the first time, clear evidence in planta that XI are involved in plant defense against fungal pathogens and show the potential to manipulate TAXI-III accumulation to improve wheat resistance against F. graminearum.

An annealed chaotic maximum neural network for bipartite subgraph problem.

PubMed

Wang, Jiahai; Tang, Zheng; Wang, Ronglong

2004-04-01

In this paper, based on maximum neural network, we propose a new parallel algorithm that can help the maximum neural network escape from local minima by including a transient chaotic neurodynamics for bipartite subgraph problem. The goal of the bipartite subgraph problem, which is an NP- complete problem, is to remove the minimum number of edges in a given graph such that the remaining graph is a bipartite graph. Lee et al. presented a parallel algorithm using the maximum neural model (winner-take-all neuron model) for this NP- complete problem. The maximum neural model always guarantees a valid solution and greatly reduces the search space without a burden on the parameter-tuning. However, the model has a tendency to converge to a local minimum easily because it is based on the steepest descent method. By adding a negative self-feedback to the maximum neural network, we proposed a new parallel algorithm that introduces richer and more flexible chaotic dynamics and can prevent the network from getting stuck at local minima. After the chaotic dynamics vanishes, the proposed algorithm is then fundamentally reined by the gradient descent dynamics and usually converges to a stable equilibrium point. The proposed algorithm has the advantages of both the maximum neural network and the chaotic neurodynamics. A large number of instances have been simulated to verify the proposed algorithm. The simulation results show that our algorithm finds the optimum or near-optimum solution for the bipartite subgraph problem superior to that of the best existing parallel algorithms.

Inferring monopartite projections of bipartite networks: an entropy-based approach

NASA Astrophysics Data System (ADS)

Saracco, Fabio; Straka, Mika J.; Di Clemente, Riccardo; Gabrielli, Andrea; Caldarelli, Guido; Squartini, Tiziano

2017-05-01

Bipartite networks are currently regarded as providing a major insight into the organization of many real-world systems, unveiling the mechanisms driving the interactions occurring between distinct groups of nodes. One of the most important issues encountered when modeling bipartite networks is devising a way to obtain a (monopartite) projection on the layer of interest, which preserves as much as possible the information encoded into the original bipartite structure. In the present paper we propose an algorithm to obtain statistically-validated projections of bipartite networks, according to which any two nodes sharing a statistically-significant number of neighbors are linked. Since assessing the statistical significance of nodes similarity requires a proper statistical benchmark, here we consider a set of four null models, defined within the exponential random graph framework. Our algorithm outputs a matrix of link-specific p-values, from which a validated projection is straightforwardly obtainable, upon running a multiple hypothesis testing procedure. Finally, we test our method on an economic network (i.e. the countries-products World Trade Web representation) and a social network (i.e. MovieLens, collecting the users’ ratings of a list of movies). In both cases non-trivial communities are detected: while projecting the World Trade Web on the countries layer reveals modules of similarly-industrialized nations, projecting it on the products layer allows communities characterized by an increasing level of complexity to be detected; in the second case, projecting MovieLens on the films layer allows clusters of movies whose affinity cannot be fully accounted for by genre similarity to be individuated.

14 CFR 330.29 - What information must air taxi operators submit on Form 330 (Final) and Form 330-C?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false What information must air taxi operators... COMPENSATION OF AIR CARRIERS Application Procedures § 330.29 What information must air taxi operators submit on Form 330 (Final) and Form 330-C? As an air taxi operator, you must complete Form 330 (Final) in...

14 CFR 330.29 - What information must air taxi operators submit on Form 330 (Final) and Form 330-C?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false What information must air taxi operators... COMPENSATION OF AIR CARRIERS Application Procedures § 330.29 What information must air taxi operators submit on Form 330 (Final) and Form 330-C? As an air taxi operator, you must complete Form 330 (Final) in...

Talent in the taxi: a model system for exploring expertise

PubMed Central

Woollett, Katherine; Spiers, Hugo J.; Maguire, Eleanor A.

2009-01-01

While there is widespread interest in and admiration of individuals with exceptional talents, surprisingly little is known about the cognitive and neural mechanisms underpinning talent, and indeed how talent relates to expertise. Because many talents are first identified and nurtured in childhood, it can be difficult to determine whether talent is innate, can be acquired through extensive practice or can only be acquired in the presence of the developing brain. We sought to address some of these issues by studying healthy adults who acquired expertise in adulthood. We focused on the domain of memory and used licensed London taxi drivers as a model system. Taxi drivers have to learn the layout of 25 000 streets in London and the locations of thousands of places of interest, and pass stringent examinations in order to obtain an operating licence. Using neuropsychological assessment and structural and functional magnetic resonance imaging, we addressed a range of key questions: in the context of a fully developed brain and an average IQ, can people acquire expertise to an exceptional level; what are the neural signatures, both structural and functional, associated with the use of expertise; does expertise change the brain compared with unskilled control participants; does it confer any cognitive advantages, and similarly, does it come at a cost to other functions? By studying retired taxi drivers, we also consider what happens to their brains and behaviour when experts stop using their skill. Finally, we discuss how the expertise of taxi drivers might relate to the issue of talent and innate abilities. We suggest that exploring talent and expertise in this manner could have implications for education, rehabilitation of patients with cognitive impairments, understanding individual differences and possibly conditions such as autism where exceptional abilities can be a feature. PMID:19528024

Aeroassisted manned transfer vehicle (TAXI) for advanced Mars Transportation: NASA/USRA 1987 Senior Design Project

NASA Technical Reports Server (NTRS)

1987-01-01

A conceptual design study of an aeroassisted orbital transfer vehicle is discussed. Nicknamed TAXI, it will ferry personnel and cargo: (1) between low Earth orbit and a spacecraft circling around the Sun in permanent orbit intersecting gravitational fields of Earth and Mars, and (2) between the cycling spacecraft and a Mars orbiting station, co-orbiting with Phobos. Crew safety and mission flexibility (in terms of ability to provide a wide range of delta-V) were given high priority. Three versions were considered, using the same overall configuration based on a low L/D aerobrake with the geometry of a raked off elliptical cone with ellipsoidal nose and a toroidal skirt. The propulsion system consists of three gimballed LOX/LH2 engines firing away from the aerobrake. The versions differ mainly in the size of the aeroshields and propellant tanks. TAXI A version resulted from an initial effort to design a single transfer vehicle able to meet all delta-V requirements during the 15-year period (2025 to 2040) of Mars mission operations. TAXI B is designed to function with the cycling spacecraft moving in a simplified, nominal trajectory. On Mars missions, TAXI B would be able to meet the requirements of all the missions with a relative approach velocity near Mars of less than 9.3 km/sec. Finally, TAXI C is a revision of TAXI A, a transfer vehicle designed for missions with a relative velocity near Mars larger than 9.3 km/sec. All versions carry a crew of 9 (11 with modifications) and a cargo of 10000 lbm. Trip duration varies from 1 day for transfer from LEO to the cycling ship to nearly 5 days for transfer from the ship to the Phobos orbit.

Asystasia mosaic Madagascar virus: a novel bipartite begomovirus infecting the weed Asystasia gangetica in Madagascar.

PubMed

De Bruyn, Alexandre; Harimalala, Mireille; Hoareau, Murielle; Ranomenjanahary, Sahondramalala; Reynaud, Bernard; Lefeuvre, Pierre; Lett, Jean-Michel

2015-06-01

Here, we describe for the first time the complete genome sequence of a new bipartite begomovirus in Madagascar isolated from the weed Asystasia gangetica (Acanthaceae), for which we propose the tentative name asystasia mosaic Madagascar virus (AMMGV). DNA-A and -B nucleotide sequences of AMMGV were only distantly related to known begomovirus sequence and shared highest nucleotide sequence identity of 72.9 % (DNA-A) and 66.9 % (DNA-B) with a recently described bipartite begomovirus infecting Asystasia sp. in West Africa. Phylogenetic analysis demonstrated that this novel virus from Madagascar belongs to a new lineage of Old World bipartite begomoviruses.

Taxi Regulatory Revision in Portland Oregon : Background and Implementation

DOT National Transportation Integrated Search

1980-09-01

The Portland Council has adopted successive waves of taxi regulatory revisions. Effective in Marh, 1979, the previous ceiling on total permits was removed and entry was opened to qualified applicats. The new reulations also provided for flat, discoun...

Controlling bi-partite entanglement in multi-qubit systems

NASA Astrophysics Data System (ADS)

Plesch, Martin; Novotný, Jaroslav; Dzuráková, Zuzana; Buzek, Vladimír

2004-02-01

Bi-partite entanglement in multi-qubit systems cannot be shared freely. The rules of quantum mechanics impose bounds on how multi-qubit systems can be correlated. In this paper, we utilize a concept of entangled graphs with weighted edges in order to analyse pure quantum states of multi-qubit systems. Here qubits are represented by vertexes of the graph, while the presence of bi-partite entanglement is represented by an edge between corresponding vertexes. The weight of each edge is defined to be the entanglement between the two qubits connected by the edge, as measured by the concurrence. We prove that each entangled graph with entanglement bounded by a specific value of the concurrence can be represented by a pure multi-qubit state. In addition, we present a logic network with O(N2) elementary gates that can be used for preparation of the weighted entangled graphs of N qubits.

Bipartite separability and nonlocal quantum operations on graphs

NASA Astrophysics Data System (ADS)

Dutta, Supriyo; Adhikari, Bibhas; Banerjee, Subhashish; Srikanth, R.

2016-07-01

In this paper we consider the separability problem for bipartite quantum states arising from graphs. Earlier it was proved that the degree criterion is the graph-theoretic counterpart of the familiar positive partial transpose criterion for separability, although there are entangled states with positive partial transpose for which the degree criterion fails. Here we introduce the concept of partially symmetric graphs and degree symmetric graphs by using the well-known concept of partial transposition of a graph and degree criteria, respectively. Thus, we provide classes of bipartite separable states of dimension m ×n arising from partially symmetric graphs. We identify partially asymmetric graphs that lack the property of partial symmetry. We develop a combinatorial procedure to create a partially asymmetric graph from a given partially symmetric graph. We show that this combinatorial operation can act as an entanglement generator for mixed states arising from partially symmetric graphs.

Global SO(3) x SO(3) x U(1) symmetry of the Hubbard model on bipartite lattices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carmelo, J.M.P., E-mail: carmelo@fisica.uminho.p; Ostlund, Stellan; Sampaio, M.J.

2010-08-15

In this paper the global symmetry of the Hubbard model on a bipartite lattice is found to be larger than SO(4). The model is one of the most studied many-particle quantum problems, yet except in one dimension it has no exact solution, so that there remain many open questions about its properties. Symmetry plays an important role in physics and often can be used to extract useful information on unsolved non-perturbative quantum problems. Specifically, here it is found that for on-site interaction U {ne} 0 the local SU(2) x SU(2) x U(1) gauge symmetry of the Hubbard model on amore » bipartite lattice with N{sub a}{sup D} sites and vanishing transfer integral t = 0 can be lifted to a global [SU(2) x SU(2) x U(1)]/Z{sub 2}{sup 2} = SO(3) x SO(3) x U(1) symmetry in the presence of the kinetic-energy hopping term of the Hamiltonian with t > 0. (Examples of a bipartite lattice are the D-dimensional cubic lattices of lattice constant a and edge length L = N{sub a}a for which D = 1, 2, 3,... in the number N{sub a}{sup D} of sites.) The generator of the new found hidden independent charge global U(1) symmetry, which is not related to the ordinary U(1) gauge subgroup of electromagnetism, is one half the rotated-electron number of singly occupied sites operator. Although addition of chemical-potential and magnetic-field operator terms to the model Hamiltonian lowers its symmetry, such terms commute with it. Therefore, its 4{sup N}{sub a}{sup D} energy eigenstates refer to representations of the new found global [SU(2) x SU(2) x U(1)]/Z{sub 2}{sup 2} = SO(3) x SO(3) x U(1) symmetry. Consistently, we find that for the Hubbard model on a bipartite lattice the number of independent representations of the group SO(3) x SO(3) x U(1) equals the Hilbert-space dimension 4{sup N}{sub a}{sup D}. It is confirmed elsewhere that the new found symmetry has important physical consequences.« less

A simple model of bipartite cooperation for ecological and organizational networks.

PubMed

Saavedra, Serguei; Reed-Tsochas, Felix; Uzzi, Brian

2009-01-22

In theoretical ecology, simple stochastic models that satisfy two basic conditions about the distribution of niche values and feeding ranges have proved successful in reproducing the overall structural properties of real food webs, using species richness and connectance as the only input parameters. Recently, more detailed models have incorporated higher levels of constraint in order to reproduce the actual links observed in real food webs. Here, building on previous stochastic models of consumer-resource interactions between species, we propose a highly parsimonious model that can reproduce the overall bipartite structure of cooperative partner-partner interactions, as exemplified by plant-animal mutualistic networks. Our stochastic model of bipartite cooperation uses simple specialization and interaction rules, and only requires three empirical input parameters. We test the bipartite cooperation model on ten large pollination data sets that have been compiled in the literature, and find that it successfully replicates the degree distribution, nestedness and modularity of the empirical networks. These properties are regarded as key to understanding cooperation in mutualistic networks. We also apply our model to an extensive data set of two classes of company engaged in joint production in the garment industry. Using the same metrics, we find that the network of manufacturer-contractor interactions exhibits similar structural patterns to plant-animal pollination networks. This surprising correspondence between ecological and organizational networks suggests that the simple rules of cooperation that generate bipartite networks may be generic, and could prove relevant in many different domains, ranging from biological systems to human society.

Health Status, Intention to Seek Health Examination, and Participation in Health Education Among Taxi Drivers in Jinan, China

PubMed Central

Yang, Yan; Fan, Xiao-sheng; Tian, Cui-huan; Zhang, Wei; Li, Jie; Li, Shu-qing

2014-01-01

Background: Taxi drivers are exposed to various risk factors such as work overload, stress, an irregular diet, and a sedentary lifestyle, which make these individuals vulnerable to many diseases. This study was designed to assess the health status of this occupational group. Objectives: The objective was to explore the health status, the intention to seek health examination, and participation in health education among taxi drivers in Jinan, China. Patients and Methods: The sample-size was determined scientifically. The systematic sampling procedure was used for selecting the sample. Four hundred taxi drivers were randomly selected from several taxi companies in Jinan. In total, 396 valid questionnaires (from 370 males and 26 females) were returned. Health status, intention to seek health examination, and participation in health education were assessed by a self-designed questionnaire. Other personal information including sex, age, ethnicity, marital status, years of employment as a taxi driver, education level, and habits were also collected. Results: This survey revealed that 54.8% of taxi drivers reported illness in the last two weeks and 44.7% of participants reported chronic diseases. The prevalence rates of hypertension, diabetes mellitus, gastroenteritis, arthritis, and heart disease were 18.2%, 8.8%, 26%, 18.4%, and 4.8% of questioned taxi drivers, respectively. Significant self-reported symptoms included fatigue, waist and back pain, headache, dyspepsia, and dry throat affecting 49.7%, 26.2%, 23.5%, 26%, and 27% of participants, respectively. In total, 90.1% of subjects thought that it was necessary to receive a regular health examination. Only 17.9% of subjects had been given information about health education, and significantly, more than 87% of subjects who had been given information about health education reported that the information had been helpful. Conclusions: Taxi drivers’ health was poor in our survey. Thus, using health education interventions

Effect of Surface Traffic Count on Taxi Time at Dallas-Fort Worth (DFW) International Airport

NASA Technical Reports Server (NTRS)

Kistler, Matthew Stephen; Gupta, Gautam

2008-01-01

As the amount of air traffic increases over the years, most airports simply do not have the means of expanding to handle the intensified traffic on the surface that will ensue. Precise surveillance equipment and automation concepts, as well as advanced surface traffic algorithms are being developed to improve airport efficiency. These surface algorithms require inputs unique to each airport to ensure maximum efficiency, and minimal taxi delay. This study analyzes surface traffic at Dallas-Fort Worth International Airport (DFW) to determine the effect of the number of aircraft on the surface and the amount of stop and go situations they experience to the amount of additional taxi time encountered. If the surface capacity of an airport is known, minimal delay can be accomplished by limiting the number of taxiing aircraft to that capacity. This concept is related to highways, where traffic flow drastically decreases as more cars occupy the road. An attempt to minimize this effect on highways is seen with the use of metering lights at freeway on-ramps. Since the surface traffic at airports is highly regulated, and aircraft are less mobile on the ground, limiting the surface count to a certain number can greatly reduce the amount of additional taxi time encountered, as well as reduce hazardous emissions. This study will also find the regions of an airport that encounter the most additional taxi time when the number of aircraft in that area is increased. This could help surface traffic algorithms avoid congesting that area, or re-route aircraft to different runways when that area reaches its capacity. The relationship between the amount of stop and go situations an aircraft encounters and their effect on the taxi time of that aircraft will also be investigated. This will help to determine the effect of holding an aircraft on the taxiway as opposed to re-routing it. The lesser of the two should be used when developing surface traffic algorithms to further minimize the

Taxi trips distribution modeling based on Entropy-Maximizing theory: A case study in Harbin city-China

NASA Astrophysics Data System (ADS)

Tang, Jinjun; Zhang, Shen; Chen, Xinqiang; Liu, Fang; Zou, Yajie

2018-03-01

Understanding Origin-Destination distribution of taxi trips is very important for improving effects of transportation planning and enhancing quality of taxi services. This study proposes a new method based on Entropy-Maximizing theory to model OD distribution in Harbin city using large-scale taxi GPS trajectories. Firstly, a K-means clustering method is utilized to partition raw pick-up and drop-off location into different zones, and trips are assumed to start from and end at zone centers. A generalized cost function is further defined by considering travel distance, time and fee between each OD pair. GPS data collected from more than 1000 taxis at an interval of 30 s during one month are divided into two parts: data from first twenty days is treated as training dataset and last ten days is taken as testing dataset. The training dataset is used to calibrate model while testing dataset is used to validate model. Furthermore, three indicators, mean absolute error (MAE), root mean square error (RMSE) and mean percentage absolute error (MPAE), are applied to evaluate training and testing performance of Entropy-Maximizing model versus Gravity model. The results demonstrate Entropy-Maximizing model is superior to Gravity model. Findings of the study are used to validate the feasibility of OD distribution from taxi GPS data in urban system.

Spatial-temporal travel pattern mining using massive taxi trajectory data

NASA Astrophysics Data System (ADS)

Zheng, Linjiang; Xia, Dong; Zhao, Xin; Tan, Longyou; Li, Hang; Chen, Li; Liu, Weining

2018-07-01

Deep understanding of residents' travel patterns would provide helpful insights into the mechanisms of many socioeconomic phenomena. With the rapid development of location-aware computing technologies, researchers have easy access to large quantities of travel data. As an important data source, taxi trajectory data are featured by their high quality, good continuity and wide distribution, making it suitable for travel pattern mining. In this paper, we use taxi trajectory data to study spatial-temporal characterization of urban residents' travel patterns from two aspects: attractive areas and hot paths. Firstly, a framework of trajectory preprocessing, including data cleaning and extracting the taxi passenger pick-up/drop-off points, is presented to reduce the noise and redundancy in raw trajectory data. Then, a grid density based clustering algorithm is proposed to discover travel attractive areas in different periods of a day. On this basis, we put forward a spatial-temporal trajectory clustering method to discover hot paths among travel attractive areas. Compared with previous algorithms, which only consider the spatial constraint between trajectories, temporal constraint is also considered in our method. Through the experiments, we discuss how to determine the optimal parameters of the two clustering algorithms and verify the effectiveness of the algorithms using real data. Furthermore, we analyze spatial-temporal characterization of Chongqing residents' travel pattern.

Motorcycle safety among motorcycle taxi drivers and nonoccupational motorcyclists in developing countries: A case study of Maoming, South China.

PubMed

Wu, Connor Y H; Loo, Becky P Y

2016-01-01

An increasing number of motorcycle taxis have been involved in traffic crashes in many developing countries. This study examines the characteristics of both motorcycle taxi drivers and nonoccupational motorcyclists, investigates the risks they pose to road safety, and provides recommendations to minimize their risks. Based on the data collected from a questionnaire survey of 867 motorcycle taxi drivers and 2,029 nonoccupational motorcyclists in Maoming, South China, comparisons were made to analyze differences of personal attributes, attitudes toward road safety, and self-reported behavior of the 2 groups. Results of the chi-square tests show that not only motorcycle taxi drivers but also nonoccupational motorcyclists in Maoming held poor attitudes toward road safety and both groups reported unsafe driving behavior. There is much room for improving local road safety education among all motorcyclists in Maoming. Yet, motorcycle taxi drivers were more likely to pose road safety risks than nonoccupational motorcyclists under some circumstances, such as speeding late at night or early in the morning, not requiring passengers to wear helmets, and running a red light. The results of the binary logistic regression model show that possessing a vehicle license for a motorcycle or not was the common significant predictor for unsafe driving behavior of motorcycle taxi drivers and nonoccupational motorcyclists. Therefore, enforcement against all motorcyclists not showing vehicle licenses for their motorcycles should be stepped up. Motorcycle safety is largely poor in Maoming. Therefore, efforts to improve motorcycle safety should be strengthened by targeting not only motorcycle taxi drivers but also nonoccupational motorcyclists.

Indianapolis Experience with Open Entry in the Taxi Industry

DOT National Transportation Integrated Search

1980-09-01

During the early 1970s the City of Indianapolis reversed a long-standing policy of closed entry into the taxi industry by redistributing many of the existing permits. This report is an account of the Indianapolis experience with open entry. It is bas...

Compliance and enforcement of a partial smoking ban in Lisbon taxis: an exploratory cross-sectional study.

PubMed

Ravara, Sofia B; Castelo-Branco, Miguel; Aguiar, Pedro; Calheiros, Jose M

2013-02-14

Research evaluating enforcement and compliance with smoking partial bans is rather scarce, especially in countries with relative weak tobacco control policies, such as Portugal. There is also scarce evidence on specific high risk groups such as vehicle workers. In January 2008, Portugal implemented a partial ban, followed by poor enforcement. The purpose of this study was to explore the effectiveness of a partial smoking ban in a pro-smoking environment, specifically transportation by taxi in the city of Lisbon. Ban effectiveness was generally defined by ban awareness and support, compliance and enforcement. Exploratory cross-sectional study; purposive sampling in selected Lisbon streets. Structured interviews were conducted by trained researchers while using taxi services (January 2009-December 2010). 250 taxi drivers (98.8% participation rate). Chi-square, McNemar, Man Whitney tests and multiple logistic regression were performed. Of the participants, 249 were male; median age was 53.0 years; 43.6% were current smokers. Most participants (82.8%) approved comprehensive bans; 84.8% reported that clients still asked to smoke in their taxis; 16.8% allowed clients to smoke. Prior to the ban this value was 76.9% (p < 0.001). The major reason for not allowing smoking was the legal ban and associated fines (71.2%). Of the smokers, 66.1% admitted smoking in their taxi. Stale smoke smells were detected in 37.6% of the cars. None of the taxi drivers did ever receive a fine for non-compliance. Heavy smoking, night-shift and allowing smoking prior the ban predicted non-compliance. Despite the strong ban support observed, high smoking prevalence and poor enforcement contribute to low compliance. The findings also suggest low compliance among night-shift and vehicle workers. This study clearly demonstrates that a partial and poorly-enforced ban is vulnerable to breaches, and highlights the need for clear and strong policies.

[A KABP (knowledge, attitude, belief and behavior) study about AIDS among taxi drivers and hotel attendants in Beijing].

PubMed

Zhang, X; Luo, B; Zhang, K

1994-12-01

This article reports the KABP study on 448 taxi drivers and 556 hotel attendants in Beijing for the first time in China. A self-administered questionnaire was used to investigate knowledge, attitude, belief and practice (KABP) about AIDS. In terms of knowledge, 23.8% of hotel attendants and 36.8% of taxi drivers did not know that contact with blood could transmit HIV. Thirtyfive percent of hotel attendants and 42.2% of taxi drivers did not believe that intravenous drug users were at high risk. Some drivers (13.6%) and hotel attendants (3.4%) reported having multiple sexual partners. Forty-one point nine percent of taxi drivers and 16.6% of hotel attendants preferred the idea of multiple sexual partners. Among hotel attendants, a negative association was found between knowledge about AIDS and multiple sexual behavior (P < 0.01). Regarding attitude toward condom use, 56.2% of taxi drivers and 47.8% of hotel attendants who have had a sexual experience thought that condom use interfered with sexual pleasure. Seventy-six point eight percent of taxi drivers and 79.8% of hotel attendants believed that they could change their behaviors in order to minimize the chances of getting HIV. This study indicates that HIV education is important in reducing the number of sexual partners and promoting the use of safe sex practices like condom use. Furthermore, as reported by the study population, education can change behavior.

Physical activity overcomes the effects of cumulative work time on hypertension prevalence among Brazilian taxi drivers.

PubMed

Vieira, Marcelo C; Sperandei, Sandro; Reis, Arianne C

2016-05-01

The aim of this study was to assess the physical activity profile of taxi drivers and its relationship with hypertension prevalence in this group of workers. Cross sectional exploratory study. Between November 2008 and April 2009, 491 taxi drivers from Rio de Janeiro, Brazil, answered a questionnaire focusing on previous hypertension diagnosis, occupational characteristics and physical activity habits. Two logistic models were developed to determine risk factors related to hypertension and to find variables associated with a higher probability of sedentarism. Hypertension prevalence was 22.6%. The workload of the group investigated was high. Results indicate that 'age', 'Body Mass Index', 'physical activity', and 'years as a taxi driver' are related to the probability of hypertension. Physical activity was shown to be a protection factor for hypertension, even considering the deleterious effect of time as a taxi driver. Our results also determined that the practice of physical activity is influenced by age, level of education and workload. It is recommended that programs to combat sedentary lifestyles as well as measures to reduce workloads be developed as strategies to prevent hypertension.

Physical activity overcomes the effects of cumulative work time on hypertension prevalence among Brazilian taxi drivers.

PubMed

Vieira, M C; Sperandei, S; Reis, A

2015-02-10

The aim of this study was to assess the physical activity profile of taxi drivers and its relationship with hypertension prevalence in this group of workers. Cross sectional exploratory study. Between November 2008 and April 2009, 491 taxi drivers from Rio de Janeiro, Brazil, answered a questionnaire focusing on previous hypertension diagnosis, occupational characteristics and physical activity habits. Two logistic models were developed to determine risk factors related to hypertension and to find variables associated with a higher probability of sedentarism. Hypertension prevalence was 22.6%. The workload of the group investigated was high. Results indicate that 'age', 'body mass index', 'physical activity', and 'years as a taxi driver' are related to the probability of hypertension. Physical activity was shown to be a protection factor for hypertension, even considering the deleterious effect of time as a taxi driver. Our results also determined that the practice of physical activity is influenced by age, level of education and workload. It is recommended that programs to combat sedentary lifestyles as well as measures to reduce workloads be developed as strategies to prevent hypertension.

Arthroscopic Excision of Bipartite Patella With Preservation of Lateral Retinaculum in an Adolescent Ice Hockey Player.

PubMed

James, Evan W; LaPrade, Christopher M; Chahla, Jorge; Cinque, Mark E; Kennedy, Nicholas I; LaPrade, Robert F

Bipartite patella usually is an asymptomatic anatomical variant. However, in some adolescent athletes, it causes anterior knee pain, resulting in decreased participation and performance. We report the case of a high-level adolescent ice hockey player who underwent successful arthroscopic excision with preservation of the lateral retinaculum of a symptomatic bipartite patella after failed nonoperative treatment. The patient returned to play by 6 weeks, and 31-month subjective follow-up scores showed high satisfaction and good clinical outcomes. For patients with a symptomatic bipartite patella, arthroscopic surgery is a good option for reducing pain and returning the athlete to competition.

Measuring the entanglement of bipartite pure states

NASA Astrophysics Data System (ADS)

Sancho, J. M.; Huelga, S. F.

2000-04-01

The problem of the experimental determination of the amount of entanglement of a bipartite pure state is addressed. We show that measuring a single observable does not suffice to determine the entanglement of a given unknown pure state of two particles. Possible minimal local measuring strategies are discussed, and a comparison is made on the basis of their best achievable precision.

76 FR 65769 - Application of Friendship Airways, Inc. d/b/a Yellow Air Taxi for Commuter Authority

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-24

... DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Friendship Airways, Inc. d/b/a Yellow Air Taxi for Commuter Authority AGENCY: Department of Transportation. ACTION: Notice of Order to... issued to Friendship Airways, Inc. d/b/a Yellow Air Taxi and deny its application to resume commuter...

Lifestyle risk factors for cardiovascular disease and diabetic risk in a sedentary occupational group: the Galway taxi driver study.

PubMed

Martin, W P; Sharif, F; Flaherty, G

2016-05-01

Taxi drivers are at increased risk of cardiovascular disease (CVD), something which persists after correcting for the overrepresentation of traditional risk factors for CVD in this cohort. The contribution of lifestyle risk factors to this residually elevated CVD risk remains under-evaluated. We aimed to determine the prevalence of lifestyle risk factors for CVD, self-reported medical risk factors for CVD, and future risk of type 2 diabetes amongst Irish taxi drivers. Male taxi drivers with no history of CVD and type 2 diabetes and working in Galway city in the west of Ireland were invited to participate. Physical activity levels, dietary patterns, anthropometry, smoking, hypertension, hypercholesterolaemia, and Finnish Diabetes Risk Score (FINDRISC) values were recorded in a cross-sectional manner. 41 taxi drivers (mean age 56.7 ± 9.8 years) participated. 37 % were insufficiently active based on self-report, although only 8 % objectively achieved 10, 000 steps per day. Mean modified Mediterranean diet score (mMDS) was 4.6 ± 2.2, and only 13 % of participants had a normal body mass index (BMI) or waist circumference (WC). Those who worked for taxi companies tended to have a higher BMI (p = .07) and WC (p = .04) by multivariable regression. 22 % were current smokers, although a quit rate of 72 % was observed amongst the 78 % of taxi drivers who had ever smoked. 25 % were at high or very high risk of future type 2 diabetes. Lifestyle risk factors for CVD and dysglycaemia are prevalent amongst Irish taxi drivers.

[Traumatic separation of a type I patella bipartite in a sportsman].

PubMed

Ottesen, Casper Smedegaard; Barfod, Kristoffer Weisskirchner; Holck, Kim

2014-05-12

This is a case report of a 44-year-old sportsman who experi-enced acute onset of strong pain and loss of ability to extend his right knee during a game of beach volley. X-ray imaging showed a patella in two parts with rounded edges and with a diastasis of more than 2 cm. Intra-operatively atrophic fibrocartilage was found on both parts of the patella. Asymptomatic patella bi-partite was found on X-ray imaging of the patient's left knee, and he was diagnosed to have traumatic separation of a type I patella bipartite. The diagnosis was confirmed by surgical and radiological findings.

Chimera states in bipartite networks of FitzHugh-Nagumo oscillators

NASA Astrophysics Data System (ADS)

Wu, Zhi-Min; Cheng, Hong-Yan; Feng, Yuee; Li, Hai-Hong; Dai, Qiong-Lin; Yang, Jun-Zhong

2018-04-01

Chimera states consisting of spatially coherent and incoherent domains have been observed in different topologies such as rings, spheres, and complex networks. In this paper, we investigate bipartite networks of nonlocally coupled FitzHugh-Nagumo (FHN) oscillators in which the units are allocated evenly to two layers, and FHN units interact with each other only when they are in different layers. We report the existence of chimera states in bipartite networks. Owing to the interplay between chimera states in the two layers, many types of chimera states such as in-phase chimera states, antiphase chimera states, and out-of-phase chimera states are classified. Stability diagrams of several typical chimera states in the coupling strength-coupling radius plane, which show strong multistability of chimera states, are explored.

Similarity-based Regularized Latent Feature Model for Link Prediction in Bipartite Networks.

PubMed

Wang, Wenjun; Chen, Xue; Jiao, Pengfei; Jin, Di

2017-12-05

Link prediction is an attractive research topic in the field of data mining and has significant applications in improving performance of recommendation system and exploring evolving mechanisms of the complex networks. A variety of complex systems in real world should be abstractly represented as bipartite networks, in which there are two types of nodes and no links connect nodes of the same type. In this paper, we propose a framework for link prediction in bipartite networks by combining the similarity based structure and the latent feature model from a new perspective. The framework is called Similarity Regularized Nonnegative Matrix Factorization (SRNMF), which explicitly takes the local characteristics into consideration and encodes the geometrical information of the networks by constructing a similarity based matrix. We also develop an iterative scheme to solve the objective function based on gradient descent. Extensive experiments on a variety of real world bipartite networks show that the proposed framework of link prediction has a more competitive, preferable and stable performance in comparison with the state-of-art methods.

The Aircraft Electric Taxi System: A Qualitative Multi Case Study

NASA Astrophysics Data System (ADS)

Johnson, Thomas Frank

The problem this research addresses is the airline industry, and the seemingly unwillingness attitude towards adopting ways to taxi aircraft without utilizing thrust from the main engines. The purpose of the study was to get a better understanding of the decision-making process of airline executives, in respect to investing in cost saving technology. A qualitative research method is used from personal interviews with 24 airline executives from two major U.S. airlines, related industry journal articles, and aircraft performance data. The following three research questions are addressed. RQ1. Does the cost of jet fuel influence airline executives' decision of adopting the aircraft electric taxi system technology? RQ2 Does the measurable payback period for a return on investment influence airline executives' decision of adopting ETS technology? RQ3. Does the amount of government assistance influence airline executives' decision of adopting ETS technology? A multi case research study design is used with a triangulation technique. The participant perceptions indicate the need to reduce operating costs, they have concerns about investment risk, and they are in favor of future government sponsored performance improvement projects. Based on the framework, findings and implications of this study, a future research paper could focus on the positive environmental effects of the ETS application. A study could be conducted on current airport area air quality and the effects that aircraft main engine thrust taxiing has on the surrounding air quality.

Information Filtering via Clustering Coefficients of User-Object Bipartite Networks

NASA Astrophysics Data System (ADS)

Guo, Qiang; Leng, Rui; Shi, Kerui; Liu, Jian-Guo

The clustering coefficient of user-object bipartite networks is presented to evaluate the overlap percentage of neighbors rating lists, which could be used to measure interest correlations among neighbor sets. The collaborative filtering (CF) information filtering algorithm evaluates a given user's interests in terms of his/her friends' opinions, which has become one of the most successful technologies for recommender systems. In this paper, different from the object clustering coefficient, users' clustering coefficients of user-object bipartite networks are introduced to improve the user similarity measurement. Numerical results for MovieLens and Netflix data sets show that users' clustering effects could enhance the algorithm performance. For MovieLens data set, the algorithmic accuracy, measured by the average ranking score, can be improved by 12.0% and the diversity could be improved by 18.2% and reach 0.649 when the recommendation list equals to 50. For Netflix data set, the accuracy could be improved by 14.5% at the optimal case and the popularity could be reduced by 13.4% comparing with the standard CF algorithm. Finally, we investigate the sparsity effect on the performance. This work indicates the user clustering coefficients is an effective factor to measure the user similarity, meanwhile statistical properties of user-object bipartite networks should be investigated to estimate users' tastes.

Ground Taxi Navigation Problems and Training Solutions

NASA Technical Reports Server (NTRS)

Quinn, Cheryl; Walter, Kim E.; Rosekind, Mark (Technical Monitor)

1997-01-01

Adverse weather conditions can put considerable strain on the National Airspace System. Even small decreases in visibility on the airport surface can create delays, hinder safe movement and lead to errors. Studies of Aviation Safety Reporting System (ASRS) surface movement incidents support the need for technologies and procedures to improve ground operations in low-visibility conditions. This study examined 139 ASRS reports of low-visibility surface movement incidents at 10 major U.S. airports. Errors were characterized in terms of incident type, contributing factors and consequences. The incidents in the present sample were comprised of runway transgressions, taxiway excursions and ground conflicts. The primary contributing factors were Airport Layout and Markings, Communication and Distraction. In half the incidents the controller issued a new clearance or the flight crew took an evasive action and in the remaining half, no recovery attempt was made because the error was detected after the fact. By gaining a better understanding the factors that affect crew navigation in low visibility and the types of errors that are likely to occur, it will be possible to develop more robust technologies to aid pilots in the ground taxi task. Implications for crew training and procedure development for low-visibility ground taxi are also discussed.

Complementarity between tripartite quantum correlation and bipartite Bell-inequality violation in three-qubit states

NASA Astrophysics Data System (ADS)

Pandya, Palash; Misra, Avijit; Chakrabarty, Indranil

2016-11-01

We find a single parameter family of genuinely entangled three-qubit pure states, called the maximally Bell-inequality violating states (MBV), which exhibit maximum Bell-inequality violation by the reduced bipartite system for a fixed amount of genuine tripartite entanglement quantified by the so-called tangle measure. This in turn implies that there holds a complementary relation between the Bell-inequality violation by the reduced bipartite systems and the tangle present in the three-qubit states, not necessarily pure. The MBV states also exhibit maximum Bell-inequality violation by the reduced bipartite systems of the three-qubit pure states with a fixed amount of genuine tripartite correlation quantified by the generalized geometric measure, a genuine entanglement measure of multiparty pure states, and the discord monogamy score, a multipartite quantum correlation measure from information-theoretic paradigm. The aforementioned complementary relation has also been established for three-qubit pure states for the generalized geometric measure and the discord monogamy score, respectively. The complementarity between the Bell-inequality violation by the reduced bipartite systems and the genuine tripartite correlation suggests that the Bell-inequality violation in the reduced two-qubit system comes at the cost of the total tripartite correlation present in the entire system.

Step On It! - Workplace cardiovascular risk assessment of New York City yellow taxi drivers

PubMed Central

Gany, Francesca; Bari, Sehrish; Gill, Pavan; Ramirez, Julia; Ayash, Claudia; Loeb, Rebecca; Aragones, Abraham; Leng, Jennifer

2015-01-01

Background Multiple factors associated with taxi driving can increase the risk of cardiovascular disease (CVD) in taxi drivers. Methods This paper describes the results of Step On It!, which assessed CVD risk factors among New York City taxi drivers at John F. Kennedy International Airport. Drivers completed an intake questionnaire and free screenings for blood pressure, glucose and body mass index (BMI). Results 466 drivers participated. 9% had random plasma glucose values >200 mg/dl. 77% had elevated BMIs. Immigrants who lived in the U.S. for >10 years had 2.5 times the odds (CI: 1.1–5.9) of having high blood pressure compared to newer immigrants. Discussion Abnormalities documented in this study were significant, especially for immigrants with greater duration of residence in the U.S., and underscore the potential for elevated CVD risk in this vulnerable population, and the need to address this risk through frameworks that utilize multiple levels of intervention. PMID:25680879

Enhancing taxi performance under low visibility : are moving maps enough?

DOT National Transportation Integrated Search

1997-09-01

We report the results of an experiment evaluating the separate and combined effects of a 3-D perspective moving map and newly developed Head-Up Display symbology on taxi performance in low visibility. Nine commercial airline pilots completed a series...

Late-Night Shared-Ride Taxi Transit in Ann Arbor, MI

DOT National Transportation Integrated Search

1984-10-01

The Ann Arbor Transportation Authority introduced Night Ride, a late-night shared-ride taxi transit service, in mid-March 1982. The service was provided through a contract with a local taxicab company and funded through a demonstration grant from the...

The xylanase inhibitor TAXI-III counteracts the necrotic activity of a Fusarium graminearum xylanase in vitro and in durum wheat transgenic plants.

PubMed

Moscetti, Ilaria; Faoro, Franco; Moro, Stefano; Sabbadin, Davide; Sella, Luca; Favaron, Francesco; D'Ovidio, Renato

2015-08-01

The xylanase inhibitor TAXI-III has been proven to delay Fusarium head blight (FHB) symptoms caused by Fusarium graminearum in transgenic durum wheat plants. To elucidate the molecular mechanism underlying the capacity of the TAXI-III transgenic plants to limit FHB symptoms, we treated wheat tissues with the xylanase FGSG_03624, hitherto shown to induce cell death and hydrogen peroxide accumulation. Experiments performed on lemmas of flowering wheat spikes and wheat cell suspension cultures demonstrated that pre-incubation of xylanase FGSG_03624 with TAXI-III significantly decreased cell death. Most interestingly, a reduced cell death relative to control non-transgenic plants was also obtained by treating, with the same xylanase, lemmas of TAXI-III transgenic plants. Molecular modelling studies predicted an interaction between the TAXI-III residue H395 and residues E122 and E214 belonging to the active site of xylanase FGSG_03624. These results provide, for the first time, clear indications in vitro and in planta that a xylanase inhibitor can prevent the necrotic activity of a xylanase, and suggest that the reduced FHB symptoms on transgenic TAXI-III plants may be a result not only of the direct inhibition of xylanase activity secreted by the pathogen, but also of the capacity of TAXI-III to avoid host cell death. © 2014 BSPP AND JOHN WILEY & SONS LTD.

Discrepancy analysis of driving performance of taxi drivers and non-professional drivers for red-light running violation and crash avoidance at intersections.

PubMed

Wu, Jiawei; Yan, Xuedong; Radwan, Essam

2016-06-01

Due to comfort, convenience, and flexibility, taxis have become increasingly more prevalent in China, especially in large cities. However, many violations and road crashes that occurred frequently were related to taxi drivers. This study aimed to investigate differences in driving performance between taxi drivers and non-professional drivers from the perspectives of red-light running violation and potential crash involvement based on a driving simulation experiment. Two typical scenarios were established in a driving simulator, which includes the red-light running violation scenario and the crash avoidance scenario. There were 49 participants, including 23 taxi drivers (14 males and 9 females) and 26 non-professional drivers (13 males and 13 females) recruited for this experiment. The driving simulation experiment results indicated that non-professional drivers paid more attention to red-light running violations in comparison to taxi drivers who had a higher probability of red-light running violation. Furthermore, it was found that taxi drivers were more inclined to turn the steering wheel in an attempt to avoid a potential collision and non-professional drivers had more abrupt deceleration behaviors when facing a potential crash. Moreover, the experiment results showed that taxi drivers had a smaller crash rate compared to non-professional drivers and had a better performance in terms of crash avoidance at the intersection. Copyright © 2016 Elsevier Ltd. All rights reserved.

Congenital bipartite atlas with hypodactyly in a dog: clinical, radiographic and CT findings.

PubMed

Wrzosek, M; Płonek, M; Zeira, O; Bieżyński, J; Kinda, W; Guziński, M

2014-07-01

A three-year-old Border collie was diagnosed with a bipartite atlas and bilateral forelimb hypodactyly. The dog showed signs of acute, non-progressive neck pain, general stiffness and right thoracic limb non-weight-bearing lameness. Computed tomography imaging revealed a bipartite atlas with abaxial vertical bone proliferation, which was the cause of the clinical signs. In addition, bilateral hypodactyly of the second and fifth digits was incidentally found. This report suggests that hypodactyly may be associated with atlas malformations. © 2014 British Small Animal Veterinary Association.

The prevalence of fatigue and associated health and safety risk factors among taxi drivers in Singapore

PubMed Central

Lim, See Ming; Chia, Sin Eng

2015-01-01

INTRODUCTION Driver fatigue is one of the biggest health and safety concerns within the road transport sector. This study aimed to determine the prevalence of fatigue among taxi drivers in Singapore, to better understand the general working and health conditions of this group of people, and to determine the risk factors associated with fatigued driving. METHODS A total of 340 taxi drivers were randomly selected for participation in a self-administered questionnaire survey, which included height and weight measurements. The response rate was 68.2%. The survey consisted of four main categories: personal particulars; social habits; work patterns; and sleep profile. The Epworth Sleepiness Scale was used to estimate the level of daytime sleepiness and fatigue. Multiple logistic regression analysis was used to estimate the adjusted odd ratios and 95% confidence intervals associated with risk factors related to fatigue among taxi drivers. RESULTS A high proportion of taxi drivers were obese and had self-reported hypertension, diabetes mellitus and high cholesterol. Driver fatigue was associated with very poor/poor self-rating of quality of sleep, having an additional part-time job, drinking three or more caffeinated drinks daily, and driving more than 10 hours a day. CONCLUSION We hope that the findings of the present study will improve awareness of the work and health conditions of taxi drivers, and contribute toward efforts to achieve a healthier workforce. A lower prevalence of fatigued driving may lead to lower risks of road traffic accidents, decreased economic loss, increased productivity, and safer roads for all. PMID:25532512

The prevalence of fatigue and associated health and safety risk factors among taxi drivers in Singapore.

PubMed

Lim, See Ming; Chia, Sin Eng

2015-02-01

Driver fatigue is one of the biggest health and safety concerns within the road transport sector. This study aimed to find out the prevalence of fatigue among taxi drivers in Singapore, to better understand the general working and health conditions of this group of people and to determine the risk factors associated with fatigued driving. A total of 340 taxi drivers were randomly selected for participation in this self-administered questionnaire survey, with height and weight measurements. The response rate was 68.2%. The survey consisted of four main categories: personal particulars; social habits; work patterns and sleep profile; and Epworth Sleepiness Scale, which was used to estimate the level of daytime sleepiness and fatigue. Multiple logistic regression analysis was used to estimate the adjusted odd ratios and 95% confidence intervals associated with the risk factors related to fatigue among the taxi drivers. A high proportion of the taxi drivers were obese and had self-reported hypertension, diabetes mellitus and high cholesterol. Driver fatigue was associated with very poor/poor self-rating of the quality of sleep, having an additional part-time job, drinking three or more caffeinated drinks daily, and driving more than 10 hours a day. We hope that the findings of the present study will improve the awareness regarding the work and health conditions of taxi drivers, and contribute toward the effort to achieve a healthier workforce. A lower prevalence of fatigued driving will lead to lower risks of road traffic accidents, decreased economic loss, increased productivity, and safer roads for all.

Compliance and enforcement of a partial smoking ban in Lisbon taxis: an exploratory cross-sectional study

PubMed Central

2013-01-01

Background Research evaluating enforcement and compliance with smoking partial bans is rather scarce, especially in countries with relative weak tobacco control policies, such as Portugal. There is also scarce evidence on specific high risk groups such as vehicle workers. In January 2008, Portugal implemented a partial ban, followed by poor enforcement. The purpose of this study was to explore the effectiveness of a partial smoking ban in a pro-smoking environment, specifically transportation by taxi in the city of Lisbon. Ban effectiveness was generally defined by ban awareness and support, compliance and enforcement. Methods Exploratory cross-sectional study; purposive sampling in selected Lisbon streets. Structured interviews were conducted by trained researchers while using taxi services (January 2009-December 2010). Participants: 250 taxi drivers (98.8% participation rate). Chi-square, McNemar, Man Whitney tests and multiple logistic regression were performed. Results Of the participants, 249 were male; median age was 53.0 years; 43.6% were current smokers. Most participants (82.8%) approved comprehensive bans; 84.8% reported that clients still asked to smoke in their taxis; 16.8% allowed clients to smoke. Prior to the ban this value was 76.9% (p < 0.001). The major reason for not allowing smoking was the legal ban and associated fines (71.2%). Of the smokers, 66.1% admitted smoking in their taxi. Stale smoke smells were detected in 37.6% of the cars. None of the taxi drivers did ever receive a fine for non-compliance. Heavy smoking, night-shift and allowing smoking prior the ban predicted non-compliance. Conclusions Despite the strong ban support observed, high smoking prevalence and poor enforcement contribute to low compliance. The findings also suggest low compliance among night-shift and vehicle workers. This study clearly demonstrates that a partial and poorly-enforced ban is vulnerable to breaches, and highlights the need for clear and strong

Bipartite qutrit local realist inequalities and the robustness of their quantum mechanical violation

NASA Astrophysics Data System (ADS)

Das, Debarshi; Datta, Shounak; Goswami, Suchetana; Majumdar, A. S.; Home, Dipankar

2017-10-01

Distinct from the type of local realist inequality (known as the Collins-Gisin-Linden-Massar-Popescu or CGLMP inequality) usually used for bipartite qutrit systems, we formulate a new set of local realist inequalities for bipartite qutrits by generalizing Wigner's argument that was originally formulated for the bipartite qubit singlet state. This treatment assumes existence of the overall joint probability distributions in the underlying stochastic hidden variable space for the measurement outcomes pertaining to the relevant trichotomic observables, satisfying the locality condition and yielding the measurable marginal probabilities. Such generalized Wigner inequalities (GWI) do not reduce to Bell-CHSH type inequalities by clubbing any two outcomes, and are violated by quantum mechanics (QM) for both the bipartite qutrit isotropic and singlet states using trichotomic observables defined by six-port beam splitter as well as by the spin-1 component observables. The efficacy of GWI is then probed in these cases by comparing the QM violation of GWI with that obtained for the CGLMP inequality. This comparison is done by incorporating white noise in the singlet and isotropic qutrit states. It is found that for the six-port beam splitter observables, QM violation of GWI is more robust than that of the CGLMP inequality for singlet qutrit states, while for isotropic qutrit states, QM violation of the CGLMP inequality is more robust. On the other hand, for the spin-1 component observables, QM violation of GWI is more robust for both the types of states considered.

Taxi Regulatory Revision in San Diego, California : Background and Implementation

DOT National Transportation Integrated Search

1981-07-01

Starting in January, 1979, the San Diego City Council revised its paratransit regulations and began issuing 6 new taxi permits per month. As of July, 1979, the ratio of new permit issuance was increased to 15 per month. Effective August 1, 1979, the ...

14 CFR 25.491 - Taxi, takeoff and landing roll.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Taxi, takeoff and landing roll. 25.491..., takeoff and landing roll. Within the range of appropriate ground speeds and approved weights, the airplane structure and landing gear are assumed to be subjected to loads not less than those obtained when the...

14 CFR 25.491 - Taxi, takeoff and landing roll.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Taxi, takeoff and landing roll. 25.491..., takeoff and landing roll. Within the range of appropriate ground speeds and approved weights, the airplane structure and landing gear are assumed to be subjected to loads not less than those obtained when the...

Labeling Residential Community Characteristics from Collective Activity Patterns Using Taxi Trip Data

NASA Astrophysics Data System (ADS)

Zhou, Y.; Fang, Z.

2017-09-01

There existing a significant social and spatial differentiation in the residential communities in urban city. People live in different places have different socioeconomic background, resulting in various geographically activity patterns. This paper aims to label the characteristics of residential communities in a city using collective activity patterns derived from taxi trip data. Specifically, we first present a method to allocate the O/D (Origin/Destination) points of taxi trips to the land use parcels where the activities taken place in. Then several indices are employed to describe the collective activity patterns, including both activity intensity, travel distance, travel time, and activity space of residents by taking account of the geographical distribution of all O/Ds of the taxi trip related to that residential community. Followed by that, an agglomerative hierarchical clustering algorithm is introduced to cluster the residential communities with similar activity patterns. In the case study of Wuhan, the residential communities are clearly divided into eight clusters, which could be labelled as ordinary communities, privileged communities, old isolated communities, suburban communities, and so on. In this paper, we provide a new perspective to label the land use under same type from people's mobility patterns with the support of big trajectory data.

Bipartite consensus for multi-agent systems with antagonistic interactions and communication delays

NASA Astrophysics Data System (ADS)

Guo, Xing; Lu, Jianquan; Alsaedi, Ahmed; Alsaadi, Fuad E.

2018-04-01

This paper studies the consensus problems over signed digraphs with arbitrary finite communication delays. For the considered system, the information flow is directed and only locally delayed information can be used for each node. We derive that bipartite consensus of this system can be realized when the associated signed digraph is strongly connected. Furthermore, for structurally balanced networks, this paper studies the pinning partite consensus for the considered system. we design a pinning scheme to pin any one agent in the signed network, and obtain that the network achieves pinning bipartite consensus with any initial conditions. Finally, two examples are provided to demonstrate the effectiveness of our main results.

Critical behavior of a chiral superfluid in a bipartite square lattice

NASA Astrophysics Data System (ADS)

Okamoto, Junichi; Huang, Wen-Min; Höppner, Robert; Mathey, Ludwig

2018-01-01

We study the critical behavior of Bose-Einstein condensation in the second band of a bipartite optical square lattice in a renormalization group framework at one-loop order. Within our field theoretical representation of the system, we approximate the system as a two-component Bose gas in three dimensions. We demonstrate that the system is in a different universality class than the previously studied condensation in a frustrated triangular lattice due to an additional Umklapp scattering term, which stabilizes the chiral superfluid order at low temperatures. We derive the renormalization group flow of the system and show that this order persists in the low energy limit. Furthermore, the renormalization flow suggests that the phase transition from the thermal phase to the chiral superfluid state is first order.

Bi-Partition of Shared Binary Decision Diagrams

DTIC Science & Technology

2002-12-01

independently. Such BDDs are considered as a special case of partitioned BDDs [6], [12], [13] and free BDDs ( FBDDs ) [7], [8]. Note that BDD nomenclature...shi, 214-8571 Japan. a)E-mail: sasao@cse.kyutech.ac.jp Applications of partitioned SBDDs are similar to that of partitioned BDDs and FBDDs . When...partitioned SBDD is more canonical than partitioned BDDs and free BDDs ( FBDDs ). We developed a heuristic bi-partition algorithm for SBDDs, and showed cases

Complete genome sequence of a new bipartite begomovirus infecting fluted pumpkin (Telfairia occidentalis) plants in Cameroon.

PubMed

Leke, Walter N; Khatabi, Behnam; Fondong, Vincent N; Brown, Judith K

2016-08-01

The complete genome sequence was determined and characterized for a previously unreported bipartite begomovirus from fluted pumpkin (Telfairia occidentalis, family Cucurbitaceae) plants displaying mosaic symptoms in Cameroon. The DNA-A and DNA-B components were ~2.7 kb and ~2.6 kb in size, and the arrangement of viral coding regions on the genomic components was like those characteristic of other known bipartite begomoviruses originating in the Old World. While the DNA-A component was more closely related to that of chayote yellow mosaic virus (ChaYMV), at 78 %, the DNA-B component was more closely related to that of soybean chlorotic blotch virus (SbCBV), at 64 %. This newly discovered bipartite Old World virus is herein named telfairia mosaic virus (TelMV).

Environmental factors associated with crash-related mortality and injury among taxi drivers in New South Wales, Australia.

PubMed

Lam, Lawrence T

2004-09-01

This exploratory study aims to investigate the associations between some environmental factors and the increased risk of motor vehicle crash-related injuries among taxi drivers. Information utilised in the study are obtained from police reports of all road traffic accidents that occurred on the roads between 1996 and 2000 in New South Wales (NSW), Australia. Of the 7923 taxi drivers who involved in crashes, nearly 10% (n = 750) were killed or injured. Results indicate sex, and two environmental factors are significantly associated with an increased risk of crash-related mortality and injury among taxi drivers. The adjusted relative risk of crash-related mortality and injury is increased by 60% for those who work the night shift (OR = 1.59, 95%CI = 1.35-1.88), and by 20% for those who do not carry any passenger on board (OR = 1.20, 95%CI = 1.02-1.41) should these drivers involve in a crash. The increased relative risk of crash-related mortality and injury is nearly 2.5 times for female taxi drivers (OR = 2.30, 95%CI = 1.45-3.65) when compared with their male counterparts. Copyright 2003 Elsevier Ltd.

Bipartite graphs as models of population structures in evolutionary multiplayer games.

PubMed

Peña, Jorge; Rochat, Yannick

2012-01-01

By combining evolutionary game theory and graph theory, "games on graphs" study the evolutionary dynamics of frequency-dependent selection in population structures modeled as geographical or social networks. Networks are usually represented by means of unipartite graphs, and social interactions by two-person games such as the famous prisoner's dilemma. Unipartite graphs have also been used for modeling interactions going beyond pairwise interactions. In this paper, we argue that bipartite graphs are a better alternative to unipartite graphs for describing population structures in evolutionary multiplayer games. To illustrate this point, we make use of bipartite graphs to investigate, by means of computer simulations, the evolution of cooperation under the conventional and the distributed N-person prisoner's dilemma. We show that several implicit assumptions arising from the standard approach based on unipartite graphs (such as the definition of replacement neighborhoods, the intertwining of individual and group diversity, and the large overlap of interaction neighborhoods) can have a large impact on the resulting evolutionary dynamics. Our work provides a clear example of the importance of construction procedures in games on graphs, of the suitability of bigraphs and hypergraphs for computational modeling, and of the importance of concepts from social network analysis such as centrality, centralization and bipartite clustering for the understanding of dynamical processes occurring on networked population structures.

Bipartite Graphs as Models of Population Structures in Evolutionary Multiplayer Games

PubMed Central

Peña, Jorge; Rochat, Yannick

2012-01-01

By combining evolutionary game theory and graph theory, “games on graphs” study the evolutionary dynamics of frequency-dependent selection in population structures modeled as geographical or social networks. Networks are usually represented by means of unipartite graphs, and social interactions by two-person games such as the famous prisoner’s dilemma. Unipartite graphs have also been used for modeling interactions going beyond pairwise interactions. In this paper, we argue that bipartite graphs are a better alternative to unipartite graphs for describing population structures in evolutionary multiplayer games. To illustrate this point, we make use of bipartite graphs to investigate, by means of computer simulations, the evolution of cooperation under the conventional and the distributed N-person prisoner’s dilemma. We show that several implicit assumptions arising from the standard approach based on unipartite graphs (such as the definition of replacement neighborhoods, the intertwining of individual and group diversity, and the large overlap of interaction neighborhoods) can have a large impact on the resulting evolutionary dynamics. Our work provides a clear example of the importance of construction procedures in games on graphs, of the suitability of bigraphs and hypergraphs for computational modeling, and of the importance of concepts from social network analysis such as centrality, centralization and bipartite clustering for the understanding of dynamical processes occurring on networked population structures. PMID:22970237

Taxi driver speeding: Who, when, where and how? A comparative study between Shanghai and New York City.

PubMed

Huang, Yizhe; Sun, Daniel Jian; Tang, Juanyu

2018-04-03

The 3 objectives of this study are to (1) identify the driving style characteristics of taxi drivers in Shanghai and New York City (NYC) using taxi Global Positioning System (GPS) data and make a comparative analysis; (2) explore the influence of different driving style characteristics on the frequency of speeding (who and how?) and (3) explore the influence of driving style characteristics, road attributes, and environmental factors on the speeding rate (when, where, and how?) Methods: This study proposes a driver-road-environment identification (DREI) method to investigate the determinant factors of taxi speeding violations. Driving style characteristics, together with road and environment variables, were obtained based on the GPS data and auxiliary spatiotemporal data in Shanghai and NYC. The daily working hours of taxi drivers in Shanghai (18.6 h) was far more than in NYC (8.5 h). The average occupancy speed of taxi drivers in Shanghai (21.3 km/h) was similar to that of NYC (20.3 km/h). Speeders in both cities had shorter working hours and longer daily driving distance than other taxi drivers, though their daily income was similar. Speeding drivers routinely took long-distance trips (>10 km) and preferred relatively faster routes. Length of segments (1.0-1.5 km) and good traffic condition were associated with high speeding rates, whereas central business district area and secondary road were associated with low speeding rates. Moreover, many speeding violations were identified between 4:00 a.m. and 7:00 a.m. in both Shanghai and NYC and the worst period was between 5:00 a.m. and 6:00 a.m. in both cities. Characteristics of drivers, road attributes, and environment variables should be considered together when studying driver speeding behavior. Findings of this study may assist in stipulating relevant laws and regulations such as stricter offense monitoring in the early morning, long segment supervision, shift rule regulation, and working hour restriction to

Turing-Hopf bifurcations in a predator-prey model with herd behavior, quadratic mortality and prey-taxis

NASA Astrophysics Data System (ADS)

Liu, Xia; Zhang, Tonghua; Meng, Xinzhu; Zhang, Tongqian

2018-04-01

In this paper, we propose a predator-prey model with herd behavior and prey-taxis. Then, we analyze the stability and bifurcation of the positive equilibrium of the model subject to the homogeneous Neumann boundary condition. By using an abstract bifurcation theory and taking prey-tactic sensitivity coefficient as the bifurcation parameter, we obtain a branch of stable nonconstant solutions bifurcating from the positive equilibrium. Our results show that prey-taxis can yield the occurrence of spatial patterns.

Taxi Regulatory Revision in Oakland and Berkeley, California : Two Case Studies

DOT National Transportation Integrated Search

1983-06-01

A case study was performed of regulatory changes pertaining to taxicabs in Oakland and neighboring Berkeley, CA. In Oakland rates were approximately doubled and limits on the number of taxi permits removed. Companies were allowed to levy a per-trip s...

Visual exploration of big spatio-temporal urban data: a study of New York City taxi trips.

PubMed

Ferreira, Nivan; Poco, Jorge; Vo, Huy T; Freire, Juliana; Silva, Cláudio T

2013-12-01

As increasing volumes of urban data are captured and become available, new opportunities arise for data-driven analysis that can lead to improvements in the lives of citizens through evidence-based decision making and policies. In this paper, we focus on a particularly important urban data set: taxi trips. Taxis are valuable sensors and information associated with taxi trips can provide unprecedented insight into many different aspects of city life, from economic activity and human behavior to mobility patterns. But analyzing these data presents many challenges. The data are complex, containing geographical and temporal components in addition to multiple variables associated with each trip. Consequently, it is hard to specify exploratory queries and to perform comparative analyses (e.g., compare different regions over time). This problem is compounded due to the size of the data-there are on average 500,000 taxi trips each day in NYC. We propose a new model that allows users to visually query taxi trips. Besides standard analytics queries, the model supports origin-destination queries that enable the study of mobility across the city. We show that this model is able to express a wide range of spatio-temporal queries, and it is also flexible in that not only can queries be composed but also different aggregations and visual representations can be applied, allowing users to explore and compare results. We have built a scalable system that implements this model which supports interactive response times; makes use of an adaptive level-of-detail rendering strategy to generate clutter-free visualization for large results; and shows hidden details to the users in a summary through the use of overlay heat maps. We present a series of case studies motivated by traffic engineers and economists that show how our model and system enable domain experts to perform tasks that were previously unattainable for them.

Implementation of bipartite or remote unitary gates with repeater nodes

NASA Astrophysics Data System (ADS)

Yu, Li; Nemoto, Kae

2016-08-01

We propose some protocols to implement various classes of bipartite unitary operations on two remote parties with the help of repeater nodes in-between. We also present a protocol to implement a single-qubit unitary with parameters determined by a remote party with the help of up to three repeater nodes. It is assumed that the neighboring nodes are connected by noisy photonic channels, and the local gates can be performed quite accurately, while the decoherence of memories is significant. A unitary is often a part of a larger computation or communication task in a quantum network, and to reduce the amount of decoherence in other systems of the network, we focus on the goal of saving the total time for implementing a unitary including the time for entanglement preparation. We review some previously studied protocols that implement bipartite unitaries using local operations and classical communication and prior shared entanglement, and apply them to the situation with repeater nodes without prior entanglement. We find that the protocols using piecewise entanglement between neighboring nodes often require less total time compared to preparing entanglement between the two end nodes first and then performing the previously known protocols. For a generic bipartite unitary, as the number of repeater nodes increases, the total time could approach the time cost for direct signal transfer from one end node to the other. We also prove some lower bounds of the total time when there are a small number of repeater nodes. The application to position-based cryptography is discussed.

14 CFR 298.21 - Filing for registration by air taxi operators.

Code of Federal Regulations, 2010 CFR

2010-01-01

... ambulance operations, firefighting or seasonal operations); 7 Companies proposing to provide scheduled... conduct such operations under their air taxi registration; such companies must first be found fit, willing... Region Headquarters (AAL-230), 222 West 7th Avenue, Box 14, Anchorage, Alaska 99513. ...

Occupational and Personal Determinants of Musculoskeletal Disorders among Urban Taxi Drivers in Ghana

PubMed Central

Abledu, J. K.; Offei, E. B.; Abledu, G. K.

2014-01-01

Background. There is a lack of epidemiological data on musculoskeletal disorders (MSDs) among occupational drivers in Ghana. The present study seeks to estimate the prevalence, body distribution, and occupational and personal determinants of MSDs in a sample of taxi drivers in the Accra Metropolis of Ghana. Methods. A total of 210 participants were enrolled in this cross-sectional study. All the participants were evaluated by using a semistructured questionnaire and the standardized Nordic Musculoskeletal Disorder Questionnaire. Results. The estimated prevalence of MSDs was 70.5%. The prevalence of the various MSD domains was as follows: lower back pain (34.3%), upper back pain (16.7%), neck pain (15.2%), shoulder pain (11.0%), knee pain (10.0%), hip/thigh pain (2.9%), elbow pain (4.8%), ankle/feet pain (2.4%), and wrist/hand pain (1.9%). Multiple logistic regression analysis of the data showed that participants who were employee drivers, drove taxi more than 12 hours per day or at least 5 days per week, perceived their job as stressful, and were dissatisfied with their job were at a greater risk of developing MSDs. Conclusions. These findings call for preventive strategies and safety guidelines in order to reduce the incidence of MSDs among urban taxi drivers in Ghana. PMID:27379297

Health status, job stress and work-related injury among Los Angeles taxi drivers.

PubMed

Wang, Pin-Chieh; Delp, Linda

2014-01-01

Taxi drivers work long hours for low wages and report hypertension, weight gain, and musculoskeletal pain associated with the sedentary nature of their job, stressful working conditions, and poor dietary habits. They also experience a high work-related fatality rate. The objective of this study is to examine the association of taxi drivers' health status and level of job stress with work-related injury and determine if a potential interaction exists. A survey of 309 Los Angeles taxi drivers provides basic data on health status, job stress, and work-related injuries. We further analyzed the data using a Modified Poisson regression approach with a robust error variance to estimate the relative risk (RR) and the 95% confidence intervals (CI) of work-related injuries. Focus group results supplemented and helped interpret the quantitative data. The joint effect of good health and low job stress was associated with a large reduction in the incidence of injuries, consistent with the hypothesis that health status and stress levels modify each other on the risk of work-related injury. These results suggest that the combination of stress reduction and health management programs together with changes in the stressful conditions of the job may provide targeted avenues to prevent injuries.

Occupational and Personal Determinants of Musculoskeletal Disorders among Urban Taxi Drivers in Ghana.

PubMed

Abledu, J K; Offei, E B; Abledu, G K

2014-01-01

Background. There is a lack of epidemiological data on musculoskeletal disorders (MSDs) among occupational drivers in Ghana. The present study seeks to estimate the prevalence, body distribution, and occupational and personal determinants of MSDs in a sample of taxi drivers in the Accra Metropolis of Ghana. Methods. A total of 210 participants were enrolled in this cross-sectional study. All the participants were evaluated by using a semistructured questionnaire and the standardized Nordic Musculoskeletal Disorder Questionnaire. Results. The estimated prevalence of MSDs was 70.5%. The prevalence of the various MSD domains was as follows: lower back pain (34.3%), upper back pain (16.7%), neck pain (15.2%), shoulder pain (11.0%), knee pain (10.0%), hip/thigh pain (2.9%), elbow pain (4.8%), ankle/feet pain (2.4%), and wrist/hand pain (1.9%). Multiple logistic regression analysis of the data showed that participants who were employee drivers, drove taxi more than 12 hours per day or at least 5 days per week, perceived their job as stressful, and were dissatisfied with their job were at a greater risk of developing MSDs. Conclusions. These findings call for preventive strategies and safety guidelines in order to reduce the incidence of MSDs among urban taxi drivers in Ghana.

Modelling the evolution of a bi-partite network Peer referral in interlocking directorates*

PubMed Central

Edling, Christofer

2010-01-01

A central part of relational ties between social actors are constituted by shared affiliations and events. The action of joint participation reinforces personal ties between social actors as well as mutually shared values and norms that in turn perpetuate the patterns of social action that define groups. Therefore the study of bipartite networks is central to social science. Furthermore, the dynamics of these processes suggests that bipartite networks should not be considered static structures but rather be studied over time. In order to model the evolution of bipartite networks empirically we introduce a class of models and a Bayesian inference scheme that extends previous stochastic actor-oriented models for unimodal graphs. Contemporary research on interlocking directorates provides an area of research in which it seems reasonable to apply the model. Specifically, we address the question of how tie formation, i.e. director recruitment, contributes to the structural properties of the interlocking directorate network. For boards of directors on the Stockholm stock exchange we propose that a prolific mechanism in tie formation is that of peer referral. The results indicate that such a mechanism is present, generating multiple interlocks between boards. PMID:24944435

A lightweight neighbor-info-based routing protocol for no-base-station taxi-call system.

PubMed

Zhu, Xudong; Wang, Jinhang; Chen, Yunchao

2014-01-01

Since the quick topology change and short connection duration, the VANET has had unstable routing and wireless signal quality. This paper proposes a kind of lightweight routing protocol-LNIB for call system without base station, which is applicable to the urban taxis. LNIB maintains and predicts neighbor information dynamically, thus finding the reliable path between the source and the target. This paper describes the protocol in detail and evaluates the performance of this protocol by simulating under different nodes density and speed. The result of evaluation shows that the performance of LNIB is better than AODV which is a classic protocol in taxi-call scene.

Bipartite entangled stabilizer mutually unbiased bases as maximum cliques of Cayley graphs

NASA Astrophysics Data System (ADS)

van Dam, Wim; Howard, Mark

2011-07-01

We examine the existence and structure of particular sets of mutually unbiased bases (MUBs) in bipartite qudit systems. In contrast to well-known power-of-prime MUB constructions, we restrict ourselves to using maximally entangled stabilizer states as MUB vectors. Consequently, these bipartite entangled stabilizer MUBs (BES MUBs) provide no local information, but are sufficient and minimal for decomposing a wide variety of interesting operators including (mixtures of) Jamiołkowski states, entanglement witnesses, and more. The problem of finding such BES MUBs can be mapped, in a natural way, to that of finding maximum cliques in a family of Cayley graphs. Some relationships with known power-of-prime MUB constructions are discussed, and observables for BES MUBs are given explicitly in terms of Pauli operators.

Simplified bipartite concepts of functioning and disability recommended for interdisciplinary use of the ICF.

PubMed

Thyberg, Mikael; Arvidsson, Patrik; Thyberg, Ingrid; Nordenfelt, Lennart

2015-01-01

To argue for and propose bipartite concepts of functioning and disability, to tally with the structure of the ICF classification list, concepts of social models and clinical needs. The ICF concepts are discussed in relation to the history of ideas regarding disability concepts and the needs for such concepts in interdisciplinary rehabilitation. Bipartite concepts are presented; they refer to actual functioning, simply body functions/structures and participation, including functioning in standardized environments. Participation refers to actually performed "activities", with "activities" simply denoting things that people may do. Bipartite concepts are congruent with the ICF classification and the structure of social models of disability, suitable for clinical and interdisciplinary use and easy to understand. The issue of standardized environments represents a methodological issue rather than the conceptual issue of defining functioning and disability. An individual perspective on activity and activity limitations, i.e. the middle part of the tripartite ICF concept, is somewhat similar to concepts of traditional language that were regarded as too generalizing already in 1912, when the interactional concept of "disability in a social sense" was introduced in rehabilitation practices. Bipartite concepts of functioning and disability are recommended for interdisciplinary use of the ICF. The ICF classification is useful, but the ICF concept of activities in an individual perspective is confusing. We suggest a use of the term "activities" simply to denote things that people may do and "participation" to denote actually performed activities. Estimations of ability should be explicit about how they are related to environmental factors.

Coupling-Induced Bipartite Pointer States in Arrays of Electron Billiards: Quantum Darwinism in Action?

NASA Astrophysics Data System (ADS)

Brunner, R.; Akis, R.; Ferry, D. K.; Kuchar, F.; Meisels, R.

2008-07-01

We discuss a quantum system coupled to the environment, composed of an open array of billiards (dots) in series. Beside pointer states occurring in individual dots, we observe sets of robust states which arise only in the array. We define these new states as bipartite pointer states, since they cannot be described in terms of simple linear combinations of robust single-dot states. The classical existence of bipartite pointer states is confirmed by comparing the quantum-mechanical and classical results. The ability of the robust states to create “offspring” indicates that quantum Darwinism is in action.

Coupling-induced bipartite pointer states in arrays of electron billiards: quantum Darwinism in action?

PubMed

Brunner, R; Akis, R; Ferry, D K; Kuchar, F; Meisels, R

2008-07-11

We discuss a quantum system coupled to the environment, composed of an open array of billiards (dots) in series. Beside pointer states occurring in individual dots, we observe sets of robust states which arise only in the array. We define these new states as bipartite pointer states, since they cannot be described in terms of simple linear combinations of robust single-dot states. The classical existence of bipartite pointer states is confirmed by comparing the quantum-mechanical and classical results. The ability of the robust states to create "offspring" indicates that quantum Darwinism is in action.

Statistically Validated Networks in Bipartite Complex Systems

PubMed Central

Tumminello, Michele; Miccichè, Salvatore; Lillo, Fabrizio; Piilo, Jyrki; Mantegna, Rosario N.

2011-01-01

Many complex systems present an intrinsic bipartite structure where elements of one set link to elements of the second set. In these complex systems, such as the system of actors and movies, elements of one set are qualitatively different than elements of the other set. The properties of these complex systems are typically investigated by constructing and analyzing a projected network on one of the two sets (for example the actor network or the movie network). Complex systems are often very heterogeneous in the number of relationships that the elements of one set establish with the elements of the other set, and this heterogeneity makes it very difficult to discriminate links of the projected network that are just reflecting system's heterogeneity from links relevant to unveil the properties of the system. Here we introduce an unsupervised method to statistically validate each link of a projected network against a null hypothesis that takes into account system heterogeneity. We apply the method to a biological, an economic and a social complex system. The method we propose is able to detect network structures which are very informative about the organization and specialization of the investigated systems, and identifies those relationships between elements of the projected network that cannot be explained simply by system heterogeneity. We also show that our method applies to bipartite systems in which different relationships might have different qualitative nature, generating statistically validated networks in which such difference is preserved. PMID:21483858

Bipartite entangled stabilizer mutually unbiased bases as maximum cliques of Cayley graphs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dam, Wim van; Howard, Mark; Department of Physics, University of California, Santa Barbara, California 93106

2011-07-15

We examine the existence and structure of particular sets of mutually unbiased bases (MUBs) in bipartite qudit systems. In contrast to well-known power-of-prime MUB constructions, we restrict ourselves to using maximally entangled stabilizer states as MUB vectors. Consequently, these bipartite entangled stabilizer MUBs (BES MUBs) provide no local information, but are sufficient and minimal for decomposing a wide variety of interesting operators including (mixtures of) Jamiolkowski states, entanglement witnesses, and more. The problem of finding such BES MUBs can be mapped, in a natural way, to that of finding maximum cliques in a family of Cayley graphs. Some relationships withmore » known power-of-prime MUB constructions are discussed, and observables for BES MUBs are given explicitly in terms of Pauli operators.« less

Faster Double-Size Bipartite Multiplication out of Montgomery Multipliers

NASA Astrophysics Data System (ADS)

Yoshino, Masayuki; Okeya, Katsuyuki; Vuillaume, Camille

This paper proposes novel algorithms for computing double-size modular multiplications with few modulus-dependent precomputations. Low-end devices such as smartcards are usually equipped with hardware Montgomery multipliers. However, due to progresses of mathematical attacks, security institutions such as NIST have steadily demanded longer bit-lengths for public-key cryptography, making the multipliers quickly obsolete. In an attempt to extend the lifespan of such multipliers, double-size techniques compute modular multiplications with twice the bit-length of the multipliers. Techniques are known for extending the bit-length of classical Euclidean multipliers, of Montgomery multipliers and the combination thereof, namely bipartite multipliers. However, unlike classical and bipartite multiplications, Montgomery multiplications involve modulus-dependent precomputations, which amount to a large part of an RSA encryption or signature verification. The proposed double-size technique simulates double-size multiplications based on single-size Montgomery multipliers, and yet precomputations are essentially free: in an 2048-bit RSA encryption or signature verification with public exponent e=216+1, the proposal with a 1024-bit Montgomery multiplier is at least 1.5 times faster than previous double-size Montgomery multiplications.

Landscape complementation revealed through bipartite networks: An example with the Florida manatee

USGS Publications Warehouse

Haase, Catherine G.; Fletcher, Robert J.; Slone, Daniel H.; Reid, James P.; Butler, Susan M.

2017-01-01

Landscape complementation is an important predictor of selection and thus classic complementation measures are not sufficient in describing the process. Formalization of complementation with bipartite network can therefor reveal effects potentially missed with conventional measures.

Small City Transit : El Cajon, California : City-Wide Shared-Ride Taxi Service

DOT National Transportation Integrated Search

1976-03-01

El Cajon, California, is an illustration of a shared ride taxi service. This case study is one of thirteen examples of a transit service in a small community. The background of the community is discussed along with a description of the implementation...

Uncovering collective listening habits and music genres in bipartite networks.

PubMed

Lambiotte, R; Ausloos, M

2005-12-01

In this paper, we analyze web-downloaded data on people sharing their music library, that we use as their individual musical signatures. The system is represented by a bipartite network, nodes being the music groups and the listeners. Music groups' audience size behaves like a power law, but the individual music library size is an exponential with deviations at small values. In order to extract structures from the network, we focus on correlation matrices, that we filter by removing the least correlated links. This percolation idea-based method reveals the emergence of social communities and music genres, that are visualized by a branching representation. Evidence of collective listening habits that do not fit the neat usual genres defined by the music industry indicates an alternative way of classifying listeners and music groups. The structure of the network is also studied by a more refined method, based upon a random walk exploration of its properties. Finally, a personal identification-community imitation model for growing bipartite networks is outlined, following Potts ingredients. Simulation results do reproduce quite well the empirical data.

On Parallel Push-Relabel based Algorithms for Bipartite Maximum Matching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Langguth, Johannes; Azad, Md Ariful; Halappanavar, Mahantesh

2014-07-01

We study multithreaded push-relabel based algorithms for computing maximum cardinality matching in bipartite graphs. Matching is a fundamental combinatorial (graph) problem with applications in a wide variety of problems in science and engineering. We are motivated by its use in the context of sparse linear solvers for computing maximum transversal of a matrix. We implement and test our algorithms on several multi-socket multicore systems and compare their performance to state-of-the-art augmenting path-based serial and parallel algorithms using a testset comprised of a wide range of real-world instances. Building on several heuristics for enhancing performance, we demonstrate good scaling for themore » parallel push-relabel algorithm. We show that it is comparable to the best augmenting path-based algorithms for bipartite matching. To the best of our knowledge, this is the first extensive study of multithreaded push-relabel based algorithms. In addition to a direct impact on the applications using matching, the proposed algorithmic techniques can be extended to preflow-push based algorithms for computing maximum flow in graphs.« less

Uncovering collective listening habits and music genres in bipartite networks

NASA Astrophysics Data System (ADS)

Lambiotte, R.; Ausloos, M.

2005-12-01

In this paper, we analyze web-downloaded data on people sharing their music library, that we use as their individual musical signatures. The system is represented by a bipartite network, nodes being the music groups and the listeners. Music groups’ audience size behaves like a power law, but the individual music library size is an exponential with deviations at small values. In order to extract structures from the network, we focus on correlation matrices, that we filter by removing the least correlated links. This percolation idea-based method reveals the emergence of social communities and music genres, that are visualized by a branching representation. Evidence of collective listening habits that do not fit the neat usual genres defined by the music industry indicates an alternative way of classifying listeners and music groups. The structure of the network is also studied by a more refined method, based upon a random walk exploration of its properties. Finally, a personal identification-community imitation model for growing bipartite networks is outlined, following Potts ingredients. Simulation results do reproduce quite well the empirical data.

Bipartite fidelity and Loschmidt echo of the bosonic conformal interface

NASA Astrophysics Data System (ADS)

Zhou, Tianci; Lin, Mao

2017-12-01

We study the quantum quench problem for a class of bosonic conformal interfaces by computing the Loschmidt echo and the bipartite fidelity. The quench can be viewed as a sudden change of boundary conditions parametrized by θ when connecting two one-dimensional critical systems. They are classified by S (θ ) matrices associated with the current scattering processes on the interface. The resulting Loschmidt echo of the quench has long time algebraic decay t-α, whose exponent also appears in the finite size bipartite fidelity as L-α/2. We perform analytic and numerical calculations of the exponent α , and find that it has a quadratic dependence on the change of θ if the prior and post-quench boundary conditions are of the same type of S , while remaining 1/4 otherwise. Possible physical realizations of these interfaces include, for instance, connecting different quantum wires (Luttinger liquids), quench of the topological phase edge states, etc., and the exponent can be detected in an x-ray edge singularity-type experiment.

Tripartite-to-Bipartite Entanglement Transformation by Stochastic Local Operations and Classical Communication and the Structure of Matrix Spaces

NASA Astrophysics Data System (ADS)

Li, Yinan; Qiao, Youming; Wang, Xin; Duan, Runyao

2018-03-01

We study the problem of transforming a tripartite pure state to a bipartite one using stochastic local operations and classical communication (SLOCC). It is known that the tripartite-to-bipartite SLOCC convertibility is characterized by the maximal Schmidt rank of the given tripartite state, i.e. the largest Schmidt rank over those bipartite states lying in the support of the reduced density operator. In this paper, we further study this problem and exhibit novel results in both multi-copy and asymptotic settings, utilizing powerful results from the structure of matrix spaces. In the multi-copy regime, we observe that the maximal Schmidt rank is strictly super-multiplicative, i.e. the maximal Schmidt rank of the tensor product of two tripartite pure states can be strictly larger than the product of their maximal Schmidt ranks. We then provide a full characterization of those tripartite states whose maximal Schmidt rank is strictly super-multiplicative when taking tensor product with itself. Notice that such tripartite states admit strict advantages in tripartite-to-bipartite SLOCC transformation when multiple copies are provided. In the asymptotic setting, we focus on determining the tripartite-to-bipartite SLOCC entanglement transformation rate. Computing this rate turns out to be equivalent to computing the asymptotic maximal Schmidt rank of the tripartite state, defined as the regularization of its maximal Schmidt rank. Despite the difficulty caused by the super-multiplicative property, we provide explicit formulas for evaluating the asymptotic maximal Schmidt ranks of two important families of tripartite pure states by resorting to certain results of the structure of matrix spaces, including the study of matrix semi-invariants. These formulas turn out to be powerful enough to give a sufficient and necessary condition to determine whether a given tripartite pure state can be transformed to the bipartite maximally entangled state under SLOCC, in the asymptotic

Training and Proficiency Testing for Commuter and Air Taxi Pilots - Federal Aviation Administration

DOT National Transportation Integrated Search

1996-10-21

The objective of this audit was to determine whether the Federal Aviation : Administration (FAA) has established procedures and oversight controls to assure : that commuter and air taxi pilots, engaged in passenger-carrying operations, : hold valid p...

Potential for Flexicab Services : Innovative Uses of Taxis and Jitneys for Public Transportation

DOT National Transportation Integrated Search

1975-12-01

Taxis and jitneys can be significant urban transportation resource. Used innovatively to provide public transit services, they can offer mobility in low density areas where mass transit is not feasible, supplement mass transit economically to improve...

Enhanced capital-asset pricing model for the reconstruction of bipartite financial networks.

PubMed

Squartini, Tiziano; Almog, Assaf; Caldarelli, Guido; van Lelyveld, Iman; Garlaschelli, Diego; Cimini, Giulio

2017-09-01

Reconstructing patterns of interconnections from partial information is one of the most important issues in the statistical physics of complex networks. A paramount example is provided by financial networks. In fact, the spreading and amplification of financial distress in capital markets are strongly affected by the interconnections among financial institutions. Yet, while the aggregate balance sheets of institutions are publicly disclosed, information on single positions is mostly confidential and, as such, unavailable. Standard approaches to reconstruct the network of financial interconnection produce unrealistically dense topologies, leading to a biased estimation of systemic risk. Moreover, reconstruction techniques are generally designed for monopartite networks of bilateral exposures between financial institutions, thus failing in reproducing bipartite networks of security holdings (e.g., investment portfolios). Here we propose a reconstruction method based on constrained entropy maximization, tailored for bipartite financial networks. Such a procedure enhances the traditional capital-asset pricing model (CAPM) and allows us to reproduce the correct topology of the network. We test this enhanced CAPM (ECAPM) method on a dataset, collected by the European Central Bank, of detailed security holdings of European institutional sectors over a period of six years (2009-2015). Our approach outperforms the traditional CAPM and the recently proposed maximum-entropy CAPM both in reproducing the network topology and in estimating systemic risk due to fire sales spillovers. In general, ECAPM can be applied to the whole class of weighted bipartite networks described by the fitness model.

Enhanced capital-asset pricing model for the reconstruction of bipartite financial networks

NASA Astrophysics Data System (ADS)

Squartini, Tiziano; Almog, Assaf; Caldarelli, Guido; van Lelyveld, Iman; Garlaschelli, Diego; Cimini, Giulio

2017-09-01

Reconstructing patterns of interconnections from partial information is one of the most important issues in the statistical physics of complex networks. A paramount example is provided by financial networks. In fact, the spreading and amplification of financial distress in capital markets are strongly affected by the interconnections among financial institutions. Yet, while the aggregate balance sheets of institutions are publicly disclosed, information on single positions is mostly confidential and, as such, unavailable. Standard approaches to reconstruct the network of financial interconnection produce unrealistically dense topologies, leading to a biased estimation of systemic risk. Moreover, reconstruction techniques are generally designed for monopartite networks of bilateral exposures between financial institutions, thus failing in reproducing bipartite networks of security holdings (e.g., investment portfolios). Here we propose a reconstruction method based on constrained entropy maximization, tailored for bipartite financial networks. Such a procedure enhances the traditional capital-asset pricing model (CAPM) and allows us to reproduce the correct topology of the network. We test this enhanced CAPM (ECAPM) method on a dataset, collected by the European Central Bank, of detailed security holdings of European institutional sectors over a period of six years (2009-2015). Our approach outperforms the traditional CAPM and the recently proposed maximum-entropy CAPM both in reproducing the network topology and in estimating systemic risk due to fire sales spillovers. In general, ECAPM can be applied to the whole class of weighted bipartite networks described by the fitness model.

Bipartite Topology of Treponema pallidum Repeat Proteins C/D and I

PubMed Central

Anand, Arvind; LeDoyt, Morgan; Karanian, Carson; Luthra, Amit; Koszelak-Rosenblum, Mary; Malkowski, Michael G.; Puthenveetil, Robbins; Vinogradova, Olga; Radolf, Justin D.

2015-01-01

We previously identified Treponema pallidum repeat proteins TprC/D, TprF, and TprI as candidate outer membrane proteins (OMPs) and subsequently demonstrated that TprC is not only a rare OMP but also forms trimers and has porin activity. We also reported that TprC contains N- and C-terminal domains (TprCN and TprCC) orthologous to regions in the major outer sheath protein (MOSPN and MOSPC) of Treponema denticola and that TprCC is solely responsible for β-barrel formation, trimerization, and porin function by the full-length protein. Herein, we show that TprI also possesses bipartite architecture, trimeric structure, and porin function and that the MOSPC-like domains of native TprC and TprI are surface-exposed in T. pallidum, whereas their MOSPN-like domains are tethered within the periplasm. TprF, which does not contain a MOSPC-like domain, lacks amphiphilicity and porin activity, adopts an extended inflexible structure, and, in T. pallidum, is tightly bound to the protoplasmic cylinder. By thermal denaturation, the MOSPN and MOSPC-like domains of TprC and TprI are highly thermostable, endowing the full-length proteins with impressive conformational stability. When expressed in Escherichia coli with PelB signal sequences, TprC and TprI localize to the outer membrane, adopting bipartite topologies, whereas TprF is periplasmic. We propose that the MOSPN-like domains enhance the structural integrity of the cell envelope by anchoring the β-barrels within the periplasm. In addition to being bona fide T. pallidum rare outer membrane proteins, TprC/D and TprI represent a new class of dual function, bipartite bacterial OMP. PMID:25805501

Factors related to pilot survival in helicopter commuter and air taxi crashes.

PubMed

Krebs, M B; Li, G; Baker, S P

1995-02-01

We examined factors related to pilot survival in 167 consecutive helicopter commuter and air taxi crashes that occurred during 1983-88. Case fatality rates and adjusted odds ratios from multivariate logistic regression models were determined using data from the National Transportation Safety Board (NTSB). During this 6-year period, 29 pilots-in-command died in 167 helicopter commuter and air taxi crashes, a case fatality rate of 17.4%. Factors significantly associated with increased risk of pilot fatality were aircraft fire [odds ratio (OR) 20.0, 95% confidence interval (CI) 4.6-86.8], not using shoulder harnesses (OR 9.2, 95% CI 2.2-37.3), and aircraft with two engines (OR 4.8, 95% CI 1.3-17.4). In addition, we present data regarding success and failure of emergency flotation devices. The results suggest that the likelihood of pilot survival in helicopter crashes could be greatly improved by preventing crash associated fires and promoting the usage of shoulder restraints.

XB-70A during startup and ramp taxi

NASA Technical Reports Server (NTRS)

1968-01-01

The XB-70 was the world's largest experimental aircraft. Capable of flight at speeds of three times the speed of sound (2,000 miles per hour) at altitudes of 70,000 feet, the XB-70 was used to collect in-flight information for use in the design of future supersonic aircraft, military and civilian. This 35-second video shows the startup of the XB-70A airplane engines, the beginning of its taxi to the runway, and a turn on the ramp that shows the unique configuration of this aircraft.

Alternative Fuels Data Center: Happy Cab Fuels Taxi Fleet With CNG

Science.gov Websites

Happy Cab Fuels Taxi Fleet With CNG Find out how a cab company in Omaha, Nebraska, saves money fueling Go Electric in Florida Feb. 15, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Metropolitan Utilities District Fuels

Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in

Science.gov Websites

electric car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a Columbus, OhioA> Yellow Cab Converts Taxis to Propane in Columbus, Ohio to someone by E-mail how Yellow Cab is overhauling their fleet in Columbus, Ohio, with propane power. For information about

Evaluation of a full-time ride service program : Aspen, Colorado's Tipsy Taxi service

DOT National Transportation Integrated Search

2000-10-01

This report summarizes a study of Aspen, Colorado's Tipsy Taxi ride service program. This service, which provides a free ride home for persons who are too intoxicated to drive, has been in place since December 1983. Funded through donations from the ...

41 CFR 301-10.421 - How much will my agency reimburse me for a tip to a taxi, shuttle service, or courtesy...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false How much will my agency reimburse me for a tip to a taxi, shuttle service, or courtesy transportation driver? 301-10.421 Section 301... tip to a taxi, shuttle service, or courtesy transportation driver? An amount which your agency...

41 CFR 301-10.421 - How much will my agency reimburse me for a tip to a taxi, shuttle service, or courtesy...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false How much will my agency reimburse me for a tip to a taxi, shuttle service, or courtesy transportation driver? 301-10.421 Section 301... tip to a taxi, shuttle service, or courtesy transportation driver? An amount which your agency...

Evolving bipartite authentication graph partitions

DOE PAGES

Pope, Aaron Scott; Tauritz, Daniel Remy; Kent, Alexander D.

2017-01-16

As large scale enterprise computer networks become more ubiquitous, finding the appropriate balance between user convenience and user access control is an increasingly challenging proposition. Suboptimal partitioning of users’ access and available services contributes to the vulnerability of enterprise networks. Previous edge-cut partitioning methods unduly restrict users’ access to network resources. This paper introduces a novel method of network partitioning superior to the current state-of-the-art which minimizes user impact by providing alternate avenues for access that reduce vulnerability. Networks are modeled as bipartite authentication access graphs and a multi-objective evolutionary algorithm is used to simultaneously minimize the size of largemore » connected components while minimizing overall restrictions on network users. Lastly, results are presented on a real world data set that demonstrate the effectiveness of the introduced method compared to previous naive methods.« less

Evolving bipartite authentication graph partitions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pope, Aaron Scott; Tauritz, Daniel Remy; Kent, Alexander D.

As large scale enterprise computer networks become more ubiquitous, finding the appropriate balance between user convenience and user access control is an increasingly challenging proposition. Suboptimal partitioning of users’ access and available services contributes to the vulnerability of enterprise networks. Previous edge-cut partitioning methods unduly restrict users’ access to network resources. This paper introduces a novel method of network partitioning superior to the current state-of-the-art which minimizes user impact by providing alternate avenues for access that reduce vulnerability. Networks are modeled as bipartite authentication access graphs and a multi-objective evolutionary algorithm is used to simultaneously minimize the size of largemore » connected components while minimizing overall restrictions on network users. Lastly, results are presented on a real world data set that demonstrate the effectiveness of the introduced method compared to previous naive methods.« less

Impulsivity and risky decision making among taxi drivers in Hong Kong: An event-related potential study.

PubMed

Cheng, Andy S K; Ting, K H; Liu, Karen P Y; Ba, Yutao

2016-10-01

Taxi drivers play an important role in providing safe and professional public transport services. However, they tend to be more involved than other professional driver groups in accidents caused by deliberate recklessness. This study used an event-related potential (ERP) experiment to examine risk-taking behavior arising from impulsivity by comparing the underlying neural processes of taxi drivers with and without traffic offence records in Hong Kong. A sample of 15 traffic offenders and 15 nonoffenders, matched by sociodemographic characteristics, was recruited. The results show that the offender group demonstrated significantly less negative-going (less negative) feedback-related negativity but more positive-going (more positive) feedback-related P300 when than with their nonoffending counterparts. These findings show that taxi drivers with traffic offence records were less sensitive to the consequences of behavior and more attuned to the magnitude of potential reward. In addition, behavioral data revealed that they were more willing to make risky decisions. All these characteristics pertain to impulsive personality traits. Based on these findings, we can conclude that the offenders in this sample were more impulsive than their nonoffending counterparts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Estimate of air carrier and air taxi crash frequencies from high altitude en route flight operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanzo, D.; Kimura, C.Y.; Prassinos, P.G.

1996-06-03

In estimating the frequency of an aircraft crashing into a facility, it has been found convenient to break the problem down into two broad categories. One category estimates the aircraft crash frequency due to air traffic from nearby airports, the so-called near-airport environment. The other category estimates the aircraft crash frequency onto facilities due to air traffic from airways, jet routes, and other traffic flying outside the near-airport environment The total aircraft crash frequency is the summation of the crash frequencies from each airport near the facility under evaluation and from all airways, jet routes, and other traffic near themore » facility of interest. This paper will examine the problems associated with the determining the aircraft crash frequencies onto facilities outside the near-airport environment. This paper will further concentrate on the estimating the risk of aircraft crashes to ground facilities due to high altitude air carrier and air taxi traffic. High altitude air carrier and air taxi traffic will be defined as all air carrier and air taxi flights above 18,000 feet Mean Sea Level (MSL).« less

Synthesis of Bipartite Tetracysteine PNA Probes for DNA In Situ Fluorescent Labeling.

PubMed

Fang, Ge-Min; Seitz, Oliver

2017-12-24

"Label-free" fluorescent probes that avoid additional steps or building blocks for conjugation of fluorescent dyes with oligonucleotides can significantly reduce the time and cost of parallel bioanalysis of a large number of nucleic acid samples. A method for the synthesis of "label-free" bicysteine-modified PNA probes using solid-phase synthesis and procedures for sequence-specific DNA in situ fluorescent labeling is described here. The concept is based on the adjacent alignment of two bicysteine-modified peptide nucleic acids on a DNA target to form a structurally optimized bipartite tetracysteine motif, which induces a sequence-specific fluorogenic reaction with commercially available biarsenic dyes, even in complex media such as cell lysate. This unit will help researchers to quickly synthesize bipartite tetracysteine PNA probes and carry out low-cost DNA in situ fluorescent labeling experiments. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

User-Side Subsidies for Shared Ride Taxi Service in Danville, Illinois : Phase 1.

DOT National Transportation Integrated Search

1977-06-01

An UMTA Service and Methods Demonstration has been implemented in Danville, Illinois. The Purpose of the Demonstration is to test the use of a user-side subsidy on a shared ride taxi service for handicapped and elderly persons. This report presents t...

Ambulatory heart rate of professional taxi drivers while driving without their typical psychosocial work stressors: a pilot study.

PubMed

Choi, BongKyoo; Choi, SangJun; Jeong, JeeYeon; Lee, JiWon; Shu, Shi; Yu, Nu; Ko, SangBaek; Zhu, Yifang

2016-01-01

Few studies have examined ambulatory cardiovascular physiological parameters of taxi drivers while driving in relation to their occupational hazards. This study aims to investigate and quantify the impact of worksite physical hazards as a whole on ambulatory heart rate of professional taxi drivers while driving without their typical worksite psychosocial stressors. Ambulatory heart rate (HR driving ) of 13 non-smoking male taxi drivers (24 to 67 years old) while driving was continuously assessed on their 6-hour experimental on-road driving in Los Angeles. Percent maximum HR range (PMHR driving ) of the drivers while driving was estimated based on the individual HR driving values and US adult population resting HR (HR rest ) reference data. For analyses, the HR driving and PMHR driving data were split and averaged into 5-min segments. Five physical hazards inside taxi cabs were also monitored while driving. Work stress and work hours on typical work days were self-reported. The means of the ambulatory 5-min HR driving and PMHR driving values of the 13 drivers were 80.5 bpm (11.2 bpm higher than their mean HR rest ) and 10.7 % (range, 5.7 to 19.9 %), respectively. The means were lower than the upper limits of ambulatory HR and PMHR for a sustainable 8-hour work (35 bpm above HR rest and 30 % PMHR), although 15-27 % of the 5-min HR driving and PMHR driving values of one driver were higher than the limits. The levels of the five physical hazards among the drivers were modest: temperature (26.4 ± 3.0 °C), relative humidity (40.7 ± 10.4 %), PM 2.5 (21.5 ± 7.9  μg /m 3 ), CO 2 (1,267.1 ± 580.0 ppm) and noise (69.7 ± 3.0 dBA). The drivers worked, on average, 72 h per week and more than half of them reported that their job were often stressful. The impact of physical worksite hazards alone on ambulatory HR of professional taxi drivers in Los Angeles generally appeared to be minor. Future ambulatory heart rate studies including both

14 CFR Appendix C to Part 330 - Forms for Air Taxi Operators

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Forms for Air Taxi Operators C Appendix C to Part 330 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) PROCEDURAL REGULATIONS PROCEDURES FOR COMPENSATION OF AIR CARRIERS Pt. 330, App. C Appendix C to...

Relation between workplace accidents and the levels of carboxyhemoglobin in motorcycle taxi drivers.

PubMed

da Silva, Luiz Almeida; Robazzi, Maria Lúcia do Carmo Cruz; Terra, Fábio de Souza

2013-01-01

To investigate the relation between workplace accidents and the levels of carboxyhemoglobin found in motorcycle taxi drivers. Correlational, quantitative study involving 111 workers and data obtained in July 2012 through a questionnaire to characterize the participants and blood collection to measure carboxyhemoglobin levels. 28.8% had suffered workplace accidents; 27.6% had fractured the lower limbs and significant symptoms of carbon monoxide exposure were verified in smokers. The carboxyhemoglobin levels were higher among smokers and victims of workplace accidents. Motorcycle taxi drivers had increased levels of carboxyhemoglobin, possibly due to the exposure to carbon monoxide; these levels are also increased among smokers and victims of workplace accidents. The study provides advances in the knowledge about occupational health and environmental science, and also shows that carboxyhemoglobin can be an indicator of exposure to environmental pollutants for those working outdoors, which can be related to workplace accidents.

Autonomous taxis could greatly reduce greenhouse-gas emissions of US light-duty vehicles

NASA Astrophysics Data System (ADS)

Greenblatt, Jeffery B.; Saxena, Samveg

2015-09-01

Autonomous vehicles (AVs) are conveyances to move passengers or freight without human intervention. AVs are potentially disruptive both technologically and socially, with claimed benefits including increased safety, road utilization, driver productivity and energy savings. Here we estimate 2014 and 2030 greenhouse-gas (GHG) emissions and costs of autonomous taxis (ATs), a class of fully autonomous shared AVs likely to gain rapid early market share, through three synergistic effects: (1) future decreases in electricity GHG emissions intensity, (2) smaller vehicle sizes resulting from trip-specific AT deployment, and (3) higher annual vehicle-miles travelled (VMT), increasing high-efficiency (especially battery-electric) vehicle cost-effectiveness. Combined, these factors could result in decreased US per-mile GHG emissions in 2030 per AT deployed of 87-94% below current conventionally driven vehicles (CDVs), and 63-82% below projected 2030 hybrid vehicles, without including other energy-saving benefits of AVs. With these substantial GHG savings, ATs could enable GHG reductions even if total VMT, average speed and vehicle size increased substantially. Oil consumption would also be reduced by nearly 100%.

Prediction of safe driving Behaviours based on health belief model: the case of taxi drivers in Bandar Abbas, Iran.

PubMed

Razmara, Asghar; Aghamolaei, Teamur; Madani, Abdoulhossain; Hosseini, Zahra; Zare, Shahram

2018-03-20

Road accidents are among the main causes of mortality. As safe and secure driving is a key strategy to reduce car injuries and offenses, the present research aimed to explore safe driving behaviours among taxi drivers based on the Health Belief Model (HBM). This study was conducted on 184 taxi drivers in Bandar Abbas who were selected based on a multiple stratified sampling method. Data were collected by a questionnaire comprised of a demographic information section along with the constructs of the HBM. Data were analysed by SPSS ver19 via a Pearson's correlation coefficient and multiple regressions. The mean age of the participants was 45.1 years (SD = 11.1). They all had, on average, 10.3 (SD = 7/5) years of taxi driving experience. Among the HBM components, cues to action and perceived benefits were shown to be positively correlated with safe driving behaviours, while perceived barriers were negatively correlated. Cues to action, perceived barriers and perceived benefits were shown to be the strongest predictors of a safe drivers' behaviour. Based on the results of this study in designing health promotion programmes to improve safe driving behaviours among taxi drivers, cues to action, perceived benefits and perceived barriers are important. Therefore, advertising, the design of information campaigns, emphasis on the benefits of safe driving behaviours and modification barriers are recommended.

Subsidized Taxi Programs for Elderly and Handicapped Persons in the San Francisco Bay Area

DOT National Transportation Integrated Search

1977-09-01

The report examines subsidized taxi systems serving elderly and handicapped persons in six locations in the San Francisco Bay Area. The systems studied are San Leandro, Santa Clara County, Sunnyvale, Palo Alto, Lafayette, and Fremont. These systems a...

Exposure of Paris taxi drivers to automobile air pollutants within their vehicles

PubMed Central

Zagury, E.; Le Moullec, Y.; Momas, I.

2000-01-01

OBJECTIVES—To study the exposure of Parisian taxi drivers to automobile air pollutants during their professional activity.
METHODS—A cross sectional study was carried out from 27 January to 27 March 1997, with measurements performed in the vehicles of 29 randomly selected drivers. Carbon monoxide (CO) content was measured over an 8 hour period by a CO portable monitor. The fine suspended particles were measured according to the black smoke index (BS), with a flow controlled portable pump provided with a cellulose filter. The nitrogen oxides, NO and NO2 were measured with a passive sampler.
RESULTS—These drivers are exposed during their professional activity to relatively high concentrations of pollutants (mean, median (SD) 3.8, 2 (1.7) ppm for CO, 168, 164 (53) µg/m3 for BS, 625, 598 (224) µg/m3 for NO, and 139, 131 (43) µg/m3 for NO2.) For CO the concentrations were clearly lower than the threshold values recommended by the World Health Organisation. The situation is less satisfactory for the other pollutants, especially for the BS index. All concentrations of pollutants recorded were noticeably higher than concentrations in air recorded by the ambient Parisian air monitoring network and were close to, or slightly exceeded, the concentrations measured at the fixed stations close to automobile traffic. Pollutant concentrations were also influenced greatly by weather conditions.
CONCLUSION—This first French study conducted in taxi drivers shows that they are highly exposed to automobile pollutants. The results would justify a medical follow up of this occupational group.


Keywords: taxi drivers; exposure assessment PMID:10810130

Sitting on the runway : current aircraft taxi times now exceed pre-9/11 experience

DOT National Transportation Integrated Search

2008-05-01

Several high profi le incidents have focused attention on : tarmac delays that resulted in air travelers spending long : periods of time aboard aircraft waiting to either take off or : move to a gate after landing. Taxi-time data collected by :...

Discord as a quantum resource for bi-partite communication

NASA Astrophysics Data System (ADS)

Chrzanowski, Helen M.; Gu, Mile; Assad, Syed M.; Symul, Thomas; Modi, Kavan; Ralph, Timothy C.; Vedral, Vlatko; Lam, Ping Koy

2014-12-01

Coherent interactions that generate negligible entanglement can still exhibit unique quantum behaviour. This observation has motivated a search beyond entanglement for a complete description of all quantum correlations. Quantum discord is a promising candidate. Here, we experimentally demonstrate that under certain measurement constraints, discord between bipartite systems can be consumed to encode information that can only be accessed by coherent quantum interactions. The inability to access this information by any other means allows us to use discord to directly quantify this `quantum advantage'.

“Every disease…man can get can start in this cab”: Focus groups to identify South Asian taxi drivers’ knowledge, attitudes and beliefs about cardiovascular disease and its risks

PubMed Central

Gany, Francesca M; Gill, Pavan P; Ahmed, Ayaz; Acharya, Sudha; Leng, Jennifer

2017-01-01

Background South Asian (SA) taxi drivers potentially possess a double epidemiologic risk for cardiovascular disease (CVD) due to their ethnicity and occupation. This study investigates SA taxi drivers’ knowledge, attitudes, beliefs about general health, CVD and approaches to reduce CVD risk. Method Five focus groups were conducted with 31 SA taxi drivers in the participants’ primary language (Bengali, Hindi, Urdu or Punjabi). Audio-recordings of the sessions were transcribed, translated and entered into ATLAS.ti 6.2 for coding and analysis. Results SA drivers in an urban setting perceive themselves to be at high risk for CVD because of high work-related stress, physical inactivity, poor diet and poor health care access. Participants attributed their occupation to increasing risk for heart disease; none believed that being SA increased their risk. Discussion Interventions to lower CVD risk among SA taxi drivers should be multi-level and involve the individual drivers and the taxi industry. PMID:22843321

Quantum correlations for bipartite continuous-variable systems

NASA Astrophysics Data System (ADS)

Ma, Ruifen; Hou, Jinchuan; Qi, Xiaofei; Wang, Yangyang

2018-04-01

Two quantum correlations Q and Q_P for (m+n)-mode continuous-variable systems are introduced in terms of average distance between the reduced states under the local Gaussian positive operator-valued measurements, and analytical formulas of these quantum correlations for bipartite Gaussian states are provided. It is shown that the product states do not contain these quantum correlations, and conversely, all (m+n)-mode Gaussian states with zero quantum correlations are product states. Generally, Q≥ Q_{P}, but for the symmetric two-mode squeezed thermal states, these quantum correlations are the same and a computable formula is given. In addition, Q is compared with Gaussian geometric discord for symmetric squeezed thermal states.

Identification and functional characterization of a novel bipartite nuclear localization sequence in ARID1A.

PubMed

Bateman, Nicholas W; Shoji, Yutaka; Conrads, Kelly A; Stroop, Kevin D; Hamilton, Chad A; Darcy, Kathleen M; Maxwell, George L; Risinger, John I; Conrads, Thomas P

2016-01-01

AT-rich interactive domain-containing protein 1A (ARID1A) is a recently identified nuclear tumor suppressor frequently altered in solid tumor malignancies. We have identified a bipartite-like nuclear localization sequence (NLS) that contributes to nuclear import of ARID1A not previously described. We functionally confirm activity using GFP constructs fused with wild-type or mutant NLS sequences. We further show that cyto-nuclear localized, bipartite NLS mutant ARID1A exhibits greater stability than nuclear-localized, wild-type ARID1A. Identification of this undescribed functional NLS within ARID1A contributes vital insights to rationalize the impact of ARID1A missense mutations observed in patient tumors. Copyright © 2015 Elsevier Inc. All rights reserved.

Taking actions to quit chewing betel nuts and starting a new life: taxi drivers' successful experiences of quitting betel nut chewing.

PubMed

Yang, Tsui-Yun; Lin, Hung-Ru

2017-04-01

To understand taxi drivers' successful experiences of quitting betel nut chewing. Previous studies verified that betel nut chewing significantly increases the risk of oral cancer. In Taiwan, taxi drivers work for approximately 10-13 hours per day, and 31·7-80% of them choose to chew betel nuts for their invigorating qualities, which enable them to work more hours and receive more income. A qualitative research design was used. This study used the grounded theory method with purposive sampling to perform in-depth interviews with male taxi drivers who had successfully quit betel nut chewing for more than six months. The interviewed participants were 25 taxi drivers aged 45-67 who had chewed betel nuts for an average of 30·9 years. A constant comparative analysis of the 25 interviews revealed six categories, namely the first experience of chewing betel nuts, a part of work and life, perceiving the impact of betel nuts, trying to change, acting to quit betel nut chewing and starting a new life. During the cessation process, taxi drivers tended to be affected by their addiction to chewing betel nuts and the temptation of friends' invitations to chew betel nuts. However, their recognition of the physical effects of betel nut chewing and their sense of responsibility and commitment to family were the critical factors affecting their determination to quit betel nut chewing. Their willpower to not to chew betel nuts and the source of their motivation to exercise self-control also contributed to their success. Healthcare personnel should understand the experiences and perceptions of betel nut chewers, strengthen their understanding of the effects of betel nut chewing on physical health during the cessation period and support their self-efficacy and quitting behaviours with the assistance of significant others. © 2016 John Wiley & Sons Ltd.

Bacteriophages as scaffolds for bipartite display: designing swiss army knives on a nanoscale.

PubMed

Molek, Peter; Bratkovič, Tomaž

2015-03-18

Bacteriophages have been exploited as cloning vectors and display vehicles for decades owing to their genetic and structural simplicity. In bipartite display setting, phage takes on the role of a handle to which two modules are attached, each endowing it with specific functionality, much like the Swiss army knife. This concept offers unprecedented potential for phage applications in nanobiotechnology. Here, we compare common phage display platforms and discuss approaches to simultaneously append two or more different (poly)peptides or synthetic compounds to phage coat using genetic fusions, chemical or enzymatic conjugations, and in vitro noncovalent decoration techniques. We also review current reports on design of phage frameworks to link multiple effectors, and their use in diverse scientific disciplines. Bipartite phage display had left its mark in development of biosensors, vaccines, and targeted delivery vehicles. Furthermore, multifunctionalized phages have been utilized to template assembly of inorganic materials and protein complexes, showing promise as scaffolds in material sciences and structural biology, respectively.

Bipartite graphs in systems biology and medicine: a survey of methods and applications.

PubMed

Pavlopoulos, Georgios A; Kontou, Panagiota I; Pavlopoulou, Athanasia; Bouyioukos, Costas; Markou, Evripides; Bagos, Pantelis G

2018-04-01

The latest advances in high-throughput techniques during the past decade allowed the systems biology field to expand significantly. Today, the focus of biologists has shifted from the study of individual biological components to the study of complex biological systems and their dynamics at a larger scale. Through the discovery of novel bioentity relationships, researchers reveal new information about biological functions and processes. Graphs are widely used to represent bioentities such as proteins, genes, small molecules, ligands, and others such as nodes and their connections as edges within a network. In this review, special focus is given to the usability of bipartite graphs and their impact on the field of network biology and medicine. Furthermore, their topological properties and how these can be applied to certain biological case studies are discussed. Finally, available methodologies and software are presented, and useful insights on how bipartite graphs can shape the path toward the solution of challenging biological problems are provided.

Disentanglement in bipartite continuous-variable systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbosa, F. A. S.; Coelho, A. S.; Nussenzveig, P.

2011-11-15

Entanglement in bipartite continuous-variable systems is investigated in the presence of partial losses such as those introduced by a realistic quantum communication channel, e.g., by propagation in an optical fiber. We find that entanglement can vanish completely for partial losses, in a situation reminiscent of so-called entanglement sudden death. Even states with extreme squeezing may become separable after propagation in lossy channels. Having in mind the potential applications of such entangled light beams to optical communications, we investigate the conditions under which entanglement can survive for all partial losses. Different loss scenarios are examined, and we derive criteria to testmore » the robustness of entangled states. These criteria are necessary and sufficient for Gaussian states. Our study provides a framework to investigate the robustness of continuous-variable entanglement in more complex multipartite systems.« less

Perception and reality of particulate matter exposure in New York City taxi drivers

PubMed Central

Gany, Francesca; Bari, Sehrish; Prasad, Lakshmi; Leng, Jennifer; Lee, Trevor; Thurston, George D; Gordon, Terry; Acharya, Sudha; Zelikoff, Judith T

2017-01-01

Background Exposure to fine particulate matter (PM2.5) and black carbon (BC) have been linked to negative health risks, but exposure among professional taxi drivers is unknown. This study measured drivers' knowledge, attitudes, and beliefs (KAB) about air pollution compared to direct measures of exposures. Methods Roadside and in-vehicle levels of PM2.5 and BC were continuously measured over a single shift and compared to central site monitoring. Participants completed an air pollution KAB questionnaire. Results Taxicab PM2.5 and BC concentrations were elevated compared to central monitoring. Average PM2.5 concentrations per 15-minute interval were 4 - 49 μg/m3; 1-minute peaks measured up to 452 μg/m3. BC levels were also elevated; reaching > 10 μg/m3. 56 of 100 drivers surveyed believed they were more exposed than non-drivers; 81 believed air pollution causes health problems. Conclusions Air pollution exposure among drivers likely exceeds EPA recommendations. Future studies should focus on reducing exposures and increasing awareness among taxi drivers. PMID:27168392

The Effects of Very Light Jet Air Taxi Operations on Commercial Air Traffic

NASA Technical Reports Server (NTRS)

Smith, Jeremy C.; Dollyhigh, Samuel M.

2006-01-01

This study investigates the potential effects of Very Light Jet (VLJ) air taxi operations adding to delays experienced by commercial passenger air transportation in the year 2025. The affordable cost relative to existing business jets and ability to use many of the existing small, minimally equipped, but conveniently located airports is projected to stimulate a large demand for the aircraft. The resulting increase in air traffic operations will mainly be at smaller airports, but this study indicates that VLJs have the potential to increase further the pressure of demand at some medium and large airports, some of which are already operating at or near capacity at peak times. The additional delays to commercial passenger air transportation due to VLJ air taxi operations are obtained from simulation results using the Airspace Concepts Evaluation System (ACES) simulator. The direct increase in operating cost due to additional delays is estimated. VLJs will also cause an increase in traffic density, and this study shows increased potential for conflicts due to VLJ operations.

Evaluation of aero commander propeller acoustic data: Taxi operations

NASA Technical Reports Server (NTRS)

Piersol, A. G.; Wilby, E. G.; Wilby, J. F.

1979-01-01

The acoustic data from ground tests performed on an Aero Commander propeller driven aircraft are analyzed. An array of microphones flush mounted on the side of the fuselage were used to record data. The propeller blade passage noise during operations at several different taxi speeds is considered and calculations of the magnitude and phase of the blade passage tones, the amplitude stability of the tones, and the spatial phase and coherence of the tones are included. The measured results are compared to theoretical predictions for propeller noise and various evaluations which reveal important details of propeller noise characteristics are presented.

Optimal sequential measurements for bipartite state discrimination

NASA Astrophysics Data System (ADS)

Croke, Sarah; Barnett, Stephen M.; Weir, Graeme

2017-05-01

State discrimination is a useful test problem with which to clarify the power and limitations of different classes of measurement. We consider the problem of discriminating between given states of a bipartite quantum system via sequential measurement of the subsystems, with classical feed-forward of measurement results. Our aim is to understand when sequential measurements, which are relatively easy to implement experimentally, perform as well, or almost as well, as optimal joint measurements, which are in general more technologically challenging. We construct conditions that the optimal sequential measurement must satisfy, analogous to the well-known Helstrom conditions for minimum error discrimination in the unrestricted case. We give several examples and compare the optimal probability of correctly identifying the state via global versus sequential measurement strategies.

Optical tweezers for studying taxis in parasites

NASA Astrophysics Data System (ADS)

de Thomaz, A. A.; Fontes, A.; Stahl, C. V.; Pozzo, L. Y.; Ayres, D. C.; Almeida, D. B.; Farias, P. M. A.; Santos, B. S.; Santos-Mallet, J.; Gomes, S. A. O.; Giorgio, S.; Feder, D.; Cesar, C. L.

2011-04-01

In this work we present a methodology to measure force strengths and directions of living parasites with an optical tweezers setup. These measurements were used to study the parasites chemotaxis in real time. We observed behavior and measured the force of: (i) Leishmania amazonensis in the presence of two glucose gradients; (ii) Trypanosoma cruzi in the vicinity of the digestive system walls, and (iii) Trypanosoma rangeli in the vicinity of salivary glands as a function of distance. Our results clearly show a chemotactic behavior in every case. This methodology can be used to study any type of taxis, such as chemotaxis, osmotaxis, thermotaxis, phototaxis, of any kind of living microorganisms. These studies can help us to understand the microorganism sensory systems and their response function to these gradients.

Perseus B Taxi Tests in Preparation for a New Series of Flight Tests

NASA Image and Video Library

1998-04-27

The Perseus B remotely piloted aircraft taxis on the runway at Edwards Air Force Base, California, before a series of development flights at NASA's Dryden flight Research Center. The Perseus B is the latest of three versions of the Perseus design developed by Aurora Flight Sciences under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program.

Advanced navigation aids in the flight deck : effects on ground taxi performance under low visibility conditions

DOT National Transportation Integrated Search

1996-01-01

Reports the results of a part-task simulation evaluating the separate and combined effects of an electronic moving map display and newly developed HUD symbology on ground taxi performance, under moderate- and low-visibility conditions. Twenty-four co...

Taxi drivers' views on risky driving behavior in Tehran: a qualitative study using a social marketing approach.

PubMed

Shams, Mohsen; Shojaeizadeh, Davoud; Majdzadeh, Reza; Rashidian, Arash; Montazeri, Ali

2011-05-01

The use of the social marketing approach for public health issues is increasing. This approach uses marketing concepts borrowed from the principles of commercial marketing to promote beneficial health behaviors. In this qualitative study, four focus groups involving 42 participants were used in consumer research to explore taxi drivers' views on the driving situation and the determinants of risky driving behaviors in Tehran, as well as to gather their ideas for developing a social marketing program to reduce risky driving behaviors among taxi drivers in Tehran, Iran. Participants were asked to respond to questions that would guide the development of a marketing mix, or four Ps (product, price, place and promotion). The discussions determined that the program product should involve avoiding risky driving behaviors through increased attention to driving. They pointed out that developing and communicating with a well-designed persuasive message meant to draw their attention to driving could affect their driving behaviors. In addition, participants identified price, place and promotion strategies. They offered suggestions for marketing nonrisky driving to the target audience. The focus group discussions generated important insights into the values and the motivations that affect consumers' decisions to adopt the product. The focus group guided the development of a social marketing program to reduce risky driving behaviors in taxi drivers in Tehran, Iran. Copyright © 2010 Elsevier Ltd. All rights reserved.

TrajGraph: A Graph-Based Visual Analytics Approach to Studying Urban Network Centralities Using Taxi Trajectory Data.

PubMed

Huang, Xiaoke; Zhao, Ye; Yang, Jing; Zhang, Chong; Ma, Chao; Ye, Xinyue

2016-01-01

We propose TrajGraph, a new visual analytics method, for studying urban mobility patterns by integrating graph modeling and visual analysis with taxi trajectory data. A special graph is created to store and manifest real traffic information recorded by taxi trajectories over city streets. It conveys urban transportation dynamics which can be discovered by applying graph analysis algorithms. To support interactive, multiscale visual analytics, a graph partitioning algorithm is applied to create region-level graphs which have smaller size than the original street-level graph. Graph centralities, including Pagerank and betweenness, are computed to characterize the time-varying importance of different urban regions. The centralities are visualized by three coordinated views including a node-link graph view, a map view and a temporal information view. Users can interactively examine the importance of streets to discover and assess city traffic patterns. We have implemented a fully working prototype of this approach and evaluated it using massive taxi trajectories of Shenzhen, China. TrajGraph's capability in revealing the importance of city streets was evaluated by comparing the calculated centralities with the subjective evaluations from a group of drivers in Shenzhen. Feedback from a domain expert was collected. The effectiveness of the visual interface was evaluated through a formal user study. We also present several examples and a case study to demonstrate the usefulness of TrajGraph in urban transportation analysis.

Aspergillus prevalence in air conditioning filters from vehicles: taxis for patient transportation, forklifts, and personal vehicles.

PubMed

Viegas, Carla; Moreira, Ricardo; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Gomes, Anita Quintal; Viegas, Susana

2018-05-04

The frequency and importance of Aspergillus infections is increasing worldwide. This study aimed to assess the occupational exposure of forklifts and taxi drivers to Aspergillus spp. Nineteen filters from air conditioning system of taxis, 17 from forklifts and 37 from personal vehicles were assessed. Filters extract were streaked onto MEA, DG18 and in azole-supplemented media. Real-time quantitative PCR amplification of selected Aspergillus species-complex was also performed. Forklifts filter samples presented higher median values. Aspergillus section Nigri was the most observed in forklifts filters in MEA (28.2%) and in azole-supplemented media. DNA from Aspergillus sections Fumigati and Versicolores was successfully amplified by qPCR. This study enlightens the added value of using filters from the air conditioning system to assess Aspergillus spp. occupational exposure. Aspergillus azole resistance screening should be included in future occupational exposure assessments.

Nuclear localization of the DNA repair scaffold XRCC1: Uncovering the functional role of a bipartite NLS

DOE PAGES

Kirby, Thomas W.; Gassman, Natalie R.; Smith, Cassandra E.; ...

2015-08-25

We have characterized the nuclear localization signal (NLS) of XRCC1 structurally using X-ray crystallography and functionally using fluorescence imaging. Crystallography and binding studies confirm the bipartite nature of the XRCC1 NLS interaction with Importin α (Impα) in which the major and minor binding motifs are separated by >20 residues, and resolve previous inconsistent determinations. Binding studies of peptides corresponding to the bipartite NLS, as well as its major and minor binding motifs, to both wild-type and mutated forms of Impα reveal pronounced cooperative binding behavior that is generated by the proximity effect of the tethered major and minor motifs ofmore » the NLS. The cooperativity stems from the increased local concentration of the second motif near its cognate binding site that is a consequence of the stepwise binding behavior of the bipartite NLS. We predict that the stepwise dissociation of the NLS from Impα facilitates unloading by providing a partially complexed intermediate that is available for competitive binding by Nup50 or the Importin β binding domain. This behavior gives a basis for meeting the intrinsically conflicting high affinity and high flux requirements of an efficient nuclear transport system.« less

A mathematical model for generating bipartite graphs and its application to protein networks

NASA Astrophysics Data System (ADS)

Nacher, J. C.; Ochiai, T.; Hayashida, M.; Akutsu, T.

2009-12-01

Complex systems arise in many different contexts from large communication systems and transportation infrastructures to molecular biology. Most of these systems can be organized into networks composed of nodes and interacting edges. Here, we present a theoretical model that constructs bipartite networks with the particular feature that the degree distribution can be tuned depending on the probability rate of fundamental processes. We then use this model to investigate protein-domain networks. A protein can be composed of up to hundreds of domains. Each domain represents a conserved sequence segment with specific functional tasks. We analyze the distribution of domains in Homo sapiens and Arabidopsis thaliana organisms and the statistical analysis shows that while (a) the number of domain types shared by k proteins exhibits a power-law distribution, (b) the number of proteins composed of k types of domains decays as an exponential distribution. The proposed mathematical model generates bipartite graphs and predicts the emergence of this mixing of (a) power-law and (b) exponential distributions. Our theoretical and computational results show that this model requires (1) growth process and (2) copy mechanism.

Portraits of the Postmodern Person in "Taxi Driver,""Raging Bull," and "The King of Comedy."

ERIC Educational Resources Information Center

Mortimer, Barbara

1997-01-01

Argues that a postmodern theory of identity (i.e., the subject as coherent, integrated, discoverable self is a fiction of modernity) links Martin Scorsese's major films. Examines "Taxi Driver,""Raging Bull," and "King of Comedy." Concludes that these films articulate a major cultural shift and chronicle a…

Percolation on bipartite scale-free networks

NASA Astrophysics Data System (ADS)

Hooyberghs, H.; Van Schaeybroeck, B.; Indekeu, J. O.

2010-08-01

Recent studies introduced biased (degree-dependent) edge percolation as a model for failures in real-life systems. In this work, such process is applied to networks consisting of two types of nodes with edges running only between nodes of unlike type. Such bipartite graphs appear in many social networks, for instance in affiliation networks and in sexual-contact networks in which both types of nodes show the scale-free characteristic for the degree distribution. During the depreciation process, an edge between nodes with degrees k and q is retained with a probability proportional to (, where α is positive so that links between hubs are more prone to failure. The removal process is studied analytically by introducing a generating functions theory. We deduce exact self-consistent equations describing the system at a macroscopic level and discuss the percolation transition. Critical exponents are obtained by exploiting the Fortuin-Kasteleyn construction which provides a link between our model and a limit of the Potts model.

SibRank: Signed bipartite network analysis for neighbor-based collaborative ranking

NASA Astrophysics Data System (ADS)

Shams, Bita; Haratizadeh, Saman

2016-09-01

Collaborative ranking is an emerging field of recommender systems that utilizes users' preference data rather than rating values. Unfortunately, neighbor-based collaborative ranking has gained little attention despite its more flexibility and justifiability. This paper proposes a novel framework, called SibRank that seeks to improve the state of the art neighbor-based collaborative ranking methods. SibRank represents users' preferences as a signed bipartite network, and finds similar users, through a novel personalized ranking algorithm in signed networks.

Unbounded Violations of Bipartite Bell Inequalities via Operator Space Theory

NASA Astrophysics Data System (ADS)

Junge, M.; Palazuelos, C.; Pérez-García, D.; Villanueva, I.; Wolf, M. M.

2010-12-01

In this work we show that bipartite quantum states with local Hilbert space dimension n can violate a Bell inequality by a factor of order {Ω left(sqrt{n}/log^2n right)} when observables with n possible outcomes are used. A central tool in the analysis is a close relation between this problem and operator space theory and, in particular, the very recent noncommutative L p embedding theory. As a consequence of this result, we obtain better Hilbert space dimension witnesses and quantum violations of Bell inequalities with better resistance to noise.

A Human Subject Evaluation of Airport Surface Situational Awareness Using Prototypical Flight Deck Electronic Taxi Chart Displays

DOT National Transportation Integrated Search

1995-11-01

A study was conducted to test the effect on airport surface situational awareness of GPS derived position information : depicted on a prototypical electronic taxi chart display. The effect of position error and position uncertainty : symbology were a...

Identifying the minor set cover of dense connected bipartite graphs via random matching edge sets

NASA Astrophysics Data System (ADS)

Hamilton, Kathleen E.; Humble, Travis S.

2017-04-01

Using quantum annealing to solve an optimization problem requires minor embedding a logic graph into a known hardware graph. In an effort to reduce the complexity of the minor embedding problem, we introduce the minor set cover (MSC) of a known graph G: a subset of graph minors which contain any remaining minor of the graph as a subgraph. Any graph that can be embedded into G will be embeddable into a member of the MSC. Focusing on embedding into the hardware graph of commercially available quantum annealers, we establish the MSC for a particular known virtual hardware, which is a complete bipartite graph. We show that the complete bipartite graph K_{N,N} has a MSC of N minors, from which K_{N+1} is identified as the largest clique minor of K_{N,N}. The case of determining the largest clique minor of hardware with faults is briefly discussed but remains an open question.

Identifying the minor set cover of dense connected bipartite graphs via random matching edge sets

DOE PAGES

Hamilton, Kathleen E.; Humble, Travis S.

2017-02-23

Using quantum annealing to solve an optimization problem requires minor embedding a logic graph into a known hardware graph. We introduce the minor set cover (MSC) of a known graph GG : a subset of graph minors which contain any remaining minor of the graph as a subgraph, in an effort to reduce the complexity of the minor embedding problem. Any graph that can be embedded into GG will be embeddable into a member of the MSC. Focusing on embedding into the hardware graph of commercially available quantum annealers, we establish the MSC for a particular known virtual hardware, whichmore » is a complete bipartite graph. Furthermore, we show that the complete bipartite graph K N,N has a MSC of N minors, from which K N+1 is identified as the largest clique minor of K N,N. In the case of determining the largest clique minor of hardware with faults we briefly discussed this open question.« less

Identification and functional characterization of a novel bipartite nuclear localization sequence in ARID1A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bateman, Nicholas W.; The John P. Murtha Cancer Center, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda 20889, MD; Shoji, Yutaka

2016-01-01

AT-rich interactive domain-containing protein 1A (ARID1A) is a recently identified nuclear tumor suppressor frequently altered in solid tumor malignancies. We have identified a bipartite-like nuclear localization sequence (NLS) that contributes to nuclear import of ARID1A not previously described. We functionally confirm activity using GFP constructs fused with wild-type or mutant NLS sequences. We further show that cyto-nuclear localized, bipartite NLS mutant ARID1A exhibits greater stability than nuclear-localized, wild-type ARID1A. Identification of this undescribed functional NLS within ARID1A contributes vital insights to rationalize the impact of ARID1A missense mutations observed in patient tumors. - Highlights: • We have identified a bipartitemore » nuclear localization sequence (NLS) in ARID1A. • Confirmation of the NLS was performed using GFP constructs. • NLS mutant ARID1A exhibits greater stability than wild-type ARID1A.« less

Evidence for a bi-partition of the Younger Dryas Stadial in East Asia associated with inversed climate characteristics compared to Europe.

PubMed

Schlolaut, Gordon; Brauer, Achim; Nakagawa, Takeshi; Lamb, Henry F; Tyler, Jonathan J; Staff, Richard A; Marshall, Michael H; Bronk Ramsey, Christopher; Bryant, Charlotte L; Tarasov, Pavel E

2017-03-31

The Younger Dryas Stadial (YDS) was an episode of northern hemispheric cooling which occurred within the Last Glacial Interglacial Transition (LGIT). A major driver for the YDS climate was a weakening of the Atlantic Meridional Overturning Circulation (AMOC). It has been inferred that the AMOC began to strengthen mid-YDS, producing a bipartite structure of the YDS in records from continental Europe. These records imply that the polar front and westerlies shifted northward, producing a warmer second phase of the YDS in Europe. Here we present multi-proxy data from the sediments of Lake Suigetsu (Japan), as evidence that a related bi-partition of the YDS also occurred in East Asia. Besides showing for the first time that the bi-partition was not limited to the North Atlantic/European region, the data also imply a climatic dipole between Europe and East Asia since the cold-warm characteristics are reversed at Lake Suigetsu. We suggest that changes in eastward moisture transport from the North Atlantic are the primary mechanism by which the teleconnection can be explained.

Complexities’ day-to-day dynamic evolution analysis and prediction for a Didi taxi trip network based on complex network theory

NASA Astrophysics Data System (ADS)

Zhang, Lin; Lu, Jian; Zhou, Jialin; Zhu, Jinqing; Li, Yunxuan; Wan, Qian

2018-03-01

Didi Dache is the most popular taxi order mobile app in China, which provides online taxi-hailing service. The obtained big database from this app could be used to analyze the complexities’ day-to-day dynamic evolution of Didi taxi trip network (DTTN) from the level of complex network dynamics. First, this paper proposes the data cleaning and modeling methods for expressing Nanjing’s DTTN as a complex network. Second, the three consecutive weeks’ data are cleaned to establish 21 DTTNs based on the proposed big data processing technology. Then, multiple topology measures that characterize the complexities’ day-to-day dynamic evolution of these networks are provided. Third, these measures of 21 DTTNs are calculated and subsequently explained with actual implications. They are used as a training set for modeling the BP neural network which is designed for predicting DTTN complexities evolution. Finally, the reliability of the designed BP neural network is verified by comparing with the actual data and the results obtained from ARIMA method simultaneously. Because network complexities are the basis for modeling cascading failures and conducting link prediction in complex system, this proposed research framework not only provides a novel perspective for analyzing DTTN from the level of system aggregated behavior, but can also be used to improve the DTTN management level.

Pili-taxis: Clustering of Neisseria gonorrhoeae bacteria

NASA Astrophysics Data System (ADS)

Taktikos, Johannes; Zaburdaev, Vasily; Biais, Nicolas; Stark, Holger; Weitz, David A.

2012-02-01

The first step of colonization of Neisseria gonorrhoeae bacteria, the etiological agent of gonorrhea, is the attachment to human epithelial cells. The attachment of N. gonorrhoeae bacteria to surfaces or other cells is primarily mediated by filamentous appendages, called type IV pili (Tfp). Cycles of elongation and retraction of Tfp are responsible for a common bacterial motility called twitching motility which allows the bacteria to crawl over surfaces. Experimentally, N. gonorrhoeae cells initially dispersed over a surface agglomerate into round microcolonies within hours. It is so far not known whether this clustering is driven entirely by the Tfp dynamics or if chemotactic interactions are needed. Thus, we investigate whether the agglomeration may stem solely from the pili-mediated attraction between cells. By developing a statistical model for pili-taxis, we try to explain the experimental measurements of the time evolution of the mean cluster size, number of clusters, and area fraction covered by the cells.

Human Mars Mission Performance Crew Taxi Profile. Part 1

NASA Technical Reports Server (NTRS)

Duaro, Vince A.

1999-01-01

This timeline was generated on the Integrated Mission Program (IMP). All burn events over 2 seconds are finite with IMP solving a two point boundary value setup for begin burn time, burn time and control angles. Perigee and apogee shown above are mean orbital values. Significant events are listed. Each finite thrust event has two lines. The first is the beginning time showing the initial conditions, thrust and ISP used. The second has the end burn conditions and the delta v and time of burn. This case is an abort from the 750 x 750 phasing abort, using the taxi's main engines. An abort using the Reaction Control System (RCS) was also investigated but required a large increase in RCS propellant and was abandoned.

Strong monogamy of bipartite and genuine multipartite entanglement: the Gaussian case.

PubMed

Adesso, Gerardo; Illuminati, Fabrizio

2007-10-12

We demonstrate the existence of general constraints on distributed quantum correlations, which impose a trade-off on bipartite and multipartite entanglement at once. For all N-mode Gaussian states under permutation invariance, we establish exactly a monogamy inequality, stronger than the traditional one, that by recursion defines a proper measure of genuine N-partite entanglement. Strong monogamy holds as well for subsystems of arbitrary size, and the emerging multipartite entanglement measure is found to be scale invariant. We unveil its operational connection with the optimal fidelity of continuous variable teleportation networks.

Study of Chromatic parameters of Line, Total, Middle graphs and Graph operators of Bipartite graph

NASA Astrophysics Data System (ADS)

Nagarathinam, R.; Parvathi, N.

2018-04-01

Chromatic parameters have been explored on the basis of graph coloring process in which a couple of adjacent nodes receives different colors. But the Grundy and b-coloring executes maximum colors under certain restrictions. In this paper, Chromatic, b-chromatic and Grundy number of some graph operators of bipartite graph has been investigat

German taxi drivers' experiences and expressions of driving anger: Are the driving anger scale and the driving anger expression inventory valid measures?

PubMed

Brandenburg, Stefan; Oehl, Michael; Seigies, Kristin

2017-11-17

The objective of this article was 2-fold: firstly, we wanted to examine whether the original Driving Anger Scale (DAS) and the original Driving Anger Expression Inventory (DAX) apply to German professional taxi drivers because these scales have previously been given to professional and particularly to nonprofessional drivers in different countries. Secondly, we wanted to examine possible differences in driving anger experience and expression between professional German taxi drivers and nonprofessional German drivers. We applied German versions of the DAS, the DAX, and the State-Trait Anger Expression Inventory (STAXI) to a sample of 138 professional German taxi drivers. We then compared their ratings to the ratings of a sample of 1,136 nonprofessional German drivers (Oehl and Brandenburg n.d. ). Regarding our first objective, confirmatory factor analysis shows that the model fit of the DAS is better for nonprofessional drivers than for professional drivers. The DAX applies neither to professional nor to nonprofessional German drivers properly. Consequently, we suggest modified shorter versions of both scales for professional drivers. The STAXI applies to both professional and nonprofessional drivers. With respect to our second objective, we show that professional drivers experience significantly less driving anger than nonprofessional drivers, but they express more driving anger. We conclude that the STAXI can be applied to professional German taxi drivers. In contrast, for the DAS and the DAX we found particular shorter versions for professional taxi drivers. Especially for the DAX, most statements were too strong for German drivers to agree to. They do not show behaviors related to driving anger expression as they are described in the DAX. These problems with the original American DAX items are in line with several other studies in different countries. Future investigations should examine whether (professional) drivers from further countries express their anger

Energy as an entanglement witness for quantum many-body systems

NASA Astrophysics Data System (ADS)

Dowling, Mark R.; Doherty, Andrew C.; Bartlett, Stephen D.

2004-12-01

We investigate quantum many-body systems where all low-energy states are entangled. As a tool for quantifying such systems, we introduce the concept of the entanglement gap, which is the difference in energy between the ground-state energy and the minimum energy that a separable (unentangled) state may attain. If the energy of the system lies within the entanglement gap, the state of the system is guaranteed to be entangled. We find Hamiltonians that have the largest possible entanglement gap; for a system consisting of two interacting spin- 1/2 subsystems, the Heisenberg antiferromagnet is one such example. We also introduce a related concept, the entanglement-gap temperature: the temperature below which the thermal state is certainly entangled, as witnessed by its energy. We give an example of a bipartite Hamiltonian with an arbitrarily high entanglement-gap temperature for fixed total energy range. For bipartite spin lattices we prove a theorem demonstrating that the entanglement gap necessarily decreases as the coordination number is increased. We investigate frustrated lattices and quantum phase transitions as physical phenomena that affect the entanglement gap.

Nuclear localization of coactivator RAC3 is mediated by a bipartite NLS and importin {alpha}3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeung, Percy Luk; Zhang, Aihua; Chen, J. Don

2006-09-15

The nuclear receptor coactivator RAC3 (also known as SRC-3/ACTR/AIB1/p/CIP/TRAM-1) belongs to the p160 coactivator family, which are involved in several physiological processes and diseases. Here we have investigated how RAC3 is translocated into the nucleus and show that it is mediated through a bipartite NLS and importin {alpha}3. This bipartite NLS is located within the conserved bHLH domain, and its mutation abolished nuclear localization. The NLS is also sufficient to cause nuclear import of EGFP, and the activity requires basic amino acids within the NLS. RAC3 binds strongly to importin {alpha}3, which also depends on the basic amino acids. Functionally,more » RAC3 cytoplasmic mutant loses its ability to enhance transcription, suggesting that nuclear localization is essential for coactivator function. Together, these results reveal a previous unknown mechanism for nuclear translocation of p160 coactivators and a critical function of the conserved bHLH within the coactivator.« less

Stability of similarity measurements for bipartite networks

PubMed Central

Liu, Jian-Guo; Hou, Lei; Pan, Xue; Guo, Qiang; Zhou, Tao

2016-01-01

Similarity is a fundamental measure in network analyses and machine learning algorithms, with wide applications ranging from personalized recommendation to socio-economic dynamics. We argue that an effective similarity measurement should guarantee the stability even under some information loss. With six bipartite networks, we investigate the stabilities of fifteen similarity measurements by comparing the similarity matrixes of two data samples which are randomly divided from original data sets. Results show that, the fifteen measurements can be well classified into three clusters according to their stabilities, and measurements in the same cluster have similar mathematical definitions. In addition, we develop a top-n-stability method for personalized recommendation, and find that the unstable similarities would recommend false information to users, and the performance of recommendation would be largely improved by using stable similarity measurements. This work provides a novel dimension to analyze and evaluate similarity measurements, which can further find applications in link prediction, personalized recommendation, clustering algorithms, community detection and so on. PMID:26725688

Stability of similarity measurements for bipartite networks.

PubMed

Liu, Jian-Guo; Hou, Lei; Pan, Xue; Guo, Qiang; Zhou, Tao

2016-01-04

Similarity is a fundamental measure in network analyses and machine learning algorithms, with wide applications ranging from personalized recommendation to socio-economic dynamics. We argue that an effective similarity measurement should guarantee the stability even under some information loss. With six bipartite networks, we investigate the stabilities of fifteen similarity measurements by comparing the similarity matrixes of two data samples which are randomly divided from original data sets. Results show that, the fifteen measurements can be well classified into three clusters according to their stabilities, and measurements in the same cluster have similar mathematical definitions. In addition, we develop a top-n-stability method for personalized recommendation, and find that the unstable similarities would recommend false information to users, and the performance of recommendation would be largely improved by using stable similarity measurements. This work provides a novel dimension to analyze and evaluate similarity measurements, which can further find applications in link prediction, personalized recommendation, clustering algorithms, community detection and so on.

Parameterized Complexity Results for General Factors in Bipartite Graphs with an Application to Constraint Programming

NASA Astrophysics Data System (ADS)

Gutin, Gregory; Kim, Eun Jung; Soleimanfallah, Arezou; Szeider, Stefan; Yeo, Anders

The NP-hard general factor problem asks, given a graph and for each vertex a list of integers, whether the graph has a spanning subgraph where each vertex has a degree that belongs to its assigned list. The problem remains NP-hard even if the given graph is bipartite with partition U ⊎ V, and each vertex in U is assigned the list {1}; this subproblem appears in the context of constraint programming as the consistency problem for the extended global cardinality constraint. We show that this subproblem is fixed-parameter tractable when parameterized by the size of the second partite set V. More generally, we show that the general factor problem for bipartite graphs, parameterized by |V |, is fixed-parameter tractable as long as all vertices in U are assigned lists of length 1, but becomes W[1]-hard if vertices in U are assigned lists of length at most 2. We establish fixed-parameter tractability by reducing the problem instance to a bounded number of acyclic instances, each of which can be solved in polynomial time by dynamic programming.

On finding bicliques in bipartite graphs: a novel algorithm and its application to the integration of diverse biological data types

PubMed Central

2014-01-01

Background Integrating and analyzing heterogeneous genome-scale data is a huge algorithmic challenge for modern systems biology. Bipartite graphs can be useful for representing relationships across pairs of disparate data types, with the interpretation of these relationships accomplished through an enumeration of maximal bicliques. Most previously-known techniques are generally ill-suited to this foundational task, because they are relatively inefficient and without effective scaling. In this paper, a powerful new algorithm is described that produces all maximal bicliques in a bipartite graph. Unlike most previous approaches, the new method neither places undue restrictions on its input nor inflates the problem size. Efficiency is achieved through an innovative exploitation of bipartite graph structure, and through computational reductions that rapidly eliminate non-maximal candidates from the search space. An iterative selection of vertices for consideration based on non-decreasing common neighborhood sizes boosts efficiency and leads to more balanced recursion trees. Results The new technique is implemented and compared to previously published approaches from graph theory and data mining. Formal time and space bounds are derived. Experiments are performed on both random graphs and graphs constructed from functional genomics data. It is shown that the new method substantially outperforms the best previous alternatives. Conclusions The new method is streamlined, efficient, and particularly well-suited to the study of huge and diverse biological data. A robust implementation has been incorporated into GeneWeaver, an online tool for integrating and analyzing functional genomics experiments, available at http://geneweaver.org. The enormous increase in scalability it provides empowers users to study complex and previously unassailable gene-set associations between genes and their biological functions in a hierarchical fashion and on a genome-wide scale. This practical

Epidemic spread in bipartite network by considering risk awareness

NASA Astrophysics Data System (ADS)

Han, She; Sun, Mei; Ampimah, Benjamin Chris; Han, Dun

2018-02-01

Human awareness plays an important role in the spread of infectious diseases and the control of propagation patterns. Exploring the interplay between human awareness and epidemic spreading is a topic that has been receiving increasing attention. Considering the fact, some well-known diseases only spread between different species we propose a theoretical analysis of the Susceptible-Infected-Susceptible (SIS) epidemic spread from the perspective of bipartite network and risk aversion. Using mean field theory, the epidemic threshold is calculated theoretically. Simulation results are consistent with the proposed analytic model. The results show that, the final infection density is negative linear with the value of individuals' risk awareness. Therefore, the epidemic spread could be effectively suppressed by improving individuals' risk awareness.

View of the Soyuz carrying the Taxi crew during undocking from the ISS

NASA Image and Video Library

2001-10-31

ISS003-E-7129 (31 October 2001) --- A Soyuz spacecraft departs from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the Soyuz carrying the Taxi crew during undocking from the ISS

NASA Image and Video Library

2001-10-31

ISS003-E-7130 (31 October 2001) --- A Soyuz spacecraft departs from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

Competition for popularity in bipartite networks.

PubMed

Díaz, Mariano Beguerisse; Porter, Mason A; Onnela, Jukka-Pekka

2010-12-01

We present a dynamical model for rewiring and attachment in bipartite networks. Edges are placed between nodes that belong to catalogs that can either be fixed in size or growing in size. The model is motivated by an empirical study of data from the video rental service Netflix, which invites its users to give ratings to the videos available in its catalog. We find that the distribution of the number of ratings given by users and that of the number of ratings received by videos both follow a power law with an exponential cutoff. We also examine the activity patterns of Netflix users and find bursts of intense video-rating activity followed by long periods of inactivity. We derive ordinary differential equations to model the acquisition of edges by the nodes over time and obtain the corresponding time-dependent degree distributions. We then compare our results with the Netflix data and find good agreement. We conclude with a discussion of how catalog models can be used to study systems in which agents are forced to choose, rate, or prioritize their interactions from a large set of options. © 2010 American Institute of Physics.

Competition for popularity in bipartite networks

NASA Astrophysics Data System (ADS)

Beguerisse Díaz, Mariano; Porter, Mason A.; Onnela, Jukka-Pekka

2010-12-01

We present a dynamical model for rewiring and attachment in bipartite networks. Edges are placed between nodes that belong to catalogs that can either be fixed in size or growing in size. The model is motivated by an empirical study of data from the video rental service Netflix, which invites its users to give ratings to the videos available in its catalog. We find that the distribution of the number of ratings given by users and that of the number of ratings received by videos both follow a power law with an exponential cutoff. We also examine the activity patterns of Netflix users and find bursts of intense video-rating activity followed by long periods of inactivity. We derive ordinary differential equations to model the acquisition of edges by the nodes over time and obtain the corresponding time-dependent degree distributions. We then compare our results with the Netflix data and find good agreement. We conclude with a discussion of how catalog models can be used to study systems in which agents are forced to choose, rate, or prioritize their interactions from a large set of options.

[Comparative life cycle environmental assessment between electric taxi and gasoline taxi in Beijing].

PubMed

Shi, Xiao-Qing; Sun, Zhao-Xin; Li, Xiao-Nuo; Li, Jin-Xiang; Yang, Jian-Xin

2015-03-01

Tailpipe emission of internal combustion engine vehicle (ICEV) is one of the main sources leading to atmospheric environmental problems such as haze. Substituting electric vehicles for conventional gasoline vehicles is an important solution for reducing urban air pollution. In 2011, as a pilot city of electric vehicle, Beijing launched a promotion plan of electric vehicle. In order to compare the environmental impacts between Midi electric vehicle (Midi EV) and Hyundai gasoline taxi (ICEV), this study created an inventory with local data and well-reasoned assumptions, and contributed a life cycle assessment (LCA) model with GaBi4.4 software and comparative life cycle environmental assessment by Life cycle impact analysis models of CML2001(Problem oriented) and EI99 (Damage oriented), which included the environmental impacts of full life cycle, manufacture phase, use phase and end of life. The sensitivity analysis of lifetime mileage and power structure was also provided. The results indicated that the full life cycle environmental impact of Midi EV was smaller than Hyundai ICEV, which was mainly due to the lower fossil fuel consumption. On the contrary, Midi EV exhibited the potential of increasing the environmental impacts of ecosystem quality influence and Human health influence. By CML2001 model, the results indicated that Midi EV might decrease the impact of Abiotic Depletion Potential, Global Warming Potential, Ozone Layer Depletion Potential and so on. However, in the production phase, the impact of Abiotic Depletion Potential, Acidification Potential, Eutrophication Potential, Global Warming Potential, Photochemical Ozone Creation Potential, Ozone Layer Depletion Potential, Marine Aquatic Ecotoxicity Potential, Terrestric Ecotoxicity Potential, Human Toxicity Potential of Midi EV were increased relative to Hyundai ICEV because of emissions impacts from its power system especially the battery production. Besides, in the use phase, electricity production was

Typical Local Measurements in Generalized Probabilistic Theories: Emergence of Quantum Bipartite Correlations

NASA Astrophysics Data System (ADS)

Kleinmann, Matthias; Osborne, Tobias J.; Scholz, Volkher B.; Werner, Albert H.

2013-01-01

What singles out quantum mechanics as the fundamental theory of nature? Here we study local measurements in generalized probabilistic theories (GPTs) and investigate how observational limitations affect the production of correlations. We find that if only a subset of typical local measurements can be made then all the bipartite correlations produced in a GPT can be simulated to a high degree of accuracy by quantum mechanics. Our result makes use of a generalization of Dvoretzky’s theorem for GPTs. The tripartite correlations can go beyond those exhibited by quantum mechanics, however.

A safety monitoring system for taxi based on CMOS imager

NASA Astrophysics Data System (ADS)

Liu, Zhi

2005-01-01

CMOS image sensors now become increasingly competitive with respect to their CCD counterparts, while adding advantages such as no blooming, simpler driving requirements and the potential of on-chip integration of sensor, analogue circuitry, and digital processing functions. A safety monitoring system for taxi based on cmos imager that can record field situation when unusual circumstance happened is described in this paper. The monitoring system is based on a CMOS imager (OV7120), which can output digital image data through parallel pixel data port. The system consists of a CMOS image sensor, a large capacity NAND FLASH ROM, a USB interface chip and a micro controller (AT90S8515). The structure of whole system and the test data is discussed and analyzed in detail.

77 FR 12103 - Notice of Request for Approval of a New Information Collection: Exemptions for Air Taxi Operations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-28

... (DOT), OST, to request that the Office of Management and Budget (OMB) approve the following collection... Administration (FAA) to OST. The collection involves a classification of air carriers known as air taxi operators.... DOT-OST- 2004-16951] through one of the following methods: Federal eRulemaking Portal: http://www...

Enhancing non-local correlations in the bipartite partitions of two qubit-system with non-mutual interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohamed, A.-B.A., E-mail: abdelbastm@yahoo.com; Faculty of Science, Assiut University, Assiut; Joshi, A., E-mail: mcbamji@gmail.com

2016-03-15

Several quantum-mechanical correlations, notably, quantum entanglement, measurement-induced nonlocality and Bell nonlocality are studied for a two qubit-system having no mutual interaction. Analytical expressions for the measures of these quantum-mechanical correlations of different bipartite partitions of the system are obtained, for initially two entangled qubits and the two photons are in their vacuum states. It is found that the qubits-fields interaction leads to the loss and gain of the initial quantum correlations. The lost initial quantum correlations transfer from the qubits to the cavity fields. It is found that the maximal violation of Bell’s inequality is occurring when the quantum correlationsmore » of both the logarithmic negativity and measurement-induced nonlocality reach particular values. The maximal violation of Bell’s inequality occurs only for certain bipartite partitions of the system. The frequency detuning leads to quick oscillations of the quantum correlations and inhibits their transfer from the qubits to the cavity modes. It is also found that the dynamical behavior of the quantum correlation clearly depends on the qubit distribution angle.« less

pH-Taxis of Biohybrid Microsystems

NASA Astrophysics Data System (ADS)

Zhuang, Jiang; Wright Carlsen, Rika; Sitti, Metin

2015-06-01

The last decade has seen an increasing number of studies developing bacteria and other cell-integrated biohybrid microsystems. However, the highly stochastic motion of these microsystems severely limits their potential use. Here, we present a method that exploits the pH sensing of flagellated bacteria to realize robust drift control of multi-bacteria propelled microrobots. Under three specifically configured pH gradients, we demonstrate that the microrobots exhibit both unidirectional and bidirectional pH-tactic behaviors, which are also observed in free-swimming bacteria. From trajectory analysis, we find that the swimming direction and speed biases are two major factors that contribute to their tactic drift motion. The motion analysis of microrobots also sheds light on the propulsion dynamics of the flagellated bacteria as bioactuators. It is expected that similar driving mechanisms are shared among pH-taxis, chemotaxis, and thermotaxis. By identifying the mechanism that drives the tactic behavior of bacteria-propelled microsystems, this study opens up an avenue towards improving the control of biohybrid microsystems. Furthermore, assuming that it is possible to tune the preferred pH of bioactuators by genetic engineering, these biohybrid microsystems could potentially be applied to sense the pH gradient induced by cancerous cells in stagnant fluids inside human body and realize targeted drug delivery.

Data Acquisition Based on Stable Matching of Bipartite Graph in Cooperative Vehicle–Infrastructure Systems †

PubMed Central

Tang, Xiaolan; Hong, Donghui; Chen, Wenlong

2017-01-01

Existing studies on data acquisition in vehicular networks often take the mobile vehicular nodes as data carriers. However, their autonomous movements, limited resources and security risks impact the quality of services. In this article, we propose a data acquisition model using stable matching of bipartite graph in cooperative vehicle-infrastructure systems, namely, DAS. Contents are distributed to roadside units, while vehicular nodes support supplementary storage. The original distribution problem is formulated as a stable matching problem of bipartite graph, where the data and the storage cells compose two sides of vertices. Regarding the factors relevant with the access ratio and delay, the preference rankings for contents and roadside units are calculated, respectively. With a multi-replica preprocessing algorithm to handle the potential one-to-many mapping, the matching problem is addressed in polynomial time. In addition, vehicular nodes carry and forward assistant contents to deliver the failed packets because of bandwidth competition. Furthermore, an incentive strategy is put forward to boost the vehicle cooperation and to achieve a fair bandwidth allocation at roadside units. Experiments show that DAS achieves a high access ratio and a small storage cost with an acceptable delay. PMID:28594359

Injuries and absenteeism among motorcycle taxi drivers who are victims of traffic accidents.

PubMed

Barbosa, Kevan G N; Lucas-Neto, Alfredo; Gama, Bruno D; Lima-Neto, Jose C; Lucas, Rilva Suely C C; d'Ávila, Sérgio

2014-08-01

Facial injuries frequently occur in traffic accidents involving motorcycles. The purpose of this study was to determine the prevalence of facial injuries among motorcycle drivers who perform motorcycle taxi service. The study design was cross-sectional. A total of 210 participants who served as motorcycle taxi drivers in a city in northeastern Brazil completed a survey concerning their experience of accidents involving facial injuries and consequent hospitalization and absenteeism from work. The motorcycle drivers included in the study were randomly selected from a list provided by the city. Out of the respondents, 165 (78.6%) who were involved in traffic accidents in the last 12 months, 15 (9.1%) reported facial injuries. The types of facial injury most frequently reported involved soft tissues (n = 8; 53.3%), followed by simple fracture (n = 4; 26.7%) and dentoalveolar fracture (n = 3; 20%). We found an association between facial injuries and absenteeism, as well as an association between the presence of facial injury and the need for hospitalization for a period of 2 days or more. Respondents reported that they had accidents, but due to the use of full face motorcycle helmet the number of facial injuries was low. For most of them, absenteeism was observed for a period of one month or more. Copyright © 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

An empirical investigation of taxi driver response behavior to ride-hailing requests: A spatio-temporal perspective

PubMed Central

Xu, Ke; Sun, Luping; Wang, Hansheng

2018-01-01

Using data provided by a ride-hailing platform, this paper examines the factors that affect taxi driver response behavior to ride-hailing requests. The empirical investigation from a driver’s perspective is of great importance for ride-hailing service providers, given that approximately 40% of the hailing requests receive no response from any driver. To comprehensively understand taxi driver response behavior, we use a rich dataset to generate variables related to the spatio-temporal supply-demand intensities, the economic incentives, the requests’ and the drivers’ characteristics. The results show that drivers are more likely to respond to requests with economic incentives (especially a firm subsidy), and those with a lower spatio-temporal demand intensity or a higher spatio-temporal supply intensity. In addition, drivers are more likely to respond to requests involving rides covering a greater geographical distance and to those with a smaller number of repeated submissions. The drivers’ characteristics, namely, the number of requests received and the number of requests responded, however, have relatively little impacts on their response probability to the current request. Our findings contribute to the related literature and provide managerial implications for ride-hailing service providers. PMID:29883478

NASA's space shuttle Atlantis and its 747 carrier taxied on the Edwards Air Force Base flightline as

NASA Technical Reports Server (NTRS)

2001-01-01

NASA's space shuttle Atlantis and its 747 carrier taxied on the Edwards Air Force Base flightline as the unusual combination left for Kennedy Space Center, Florida, on March 1, 2001. Atlantis and the shuttle Columbia were both airborne on the same day as they migrated from California to Florida. Columbia underwent refurbishing at nearby Palmdale, California.

View of the Soyuz carrying the Taxi crew during undocking from the ISS

NASA Image and Video Library

2001-10-31

ISS003-E-7121 (31 October 2001) --- Backdropped by Earth’s horizon and the blackness of space, a Soyuz spacecraft undocks from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the Soyuz carrying the Taxi crew during undocking from the ISS

NASA Image and Video Library

2001-10-31

ISS003-E-7127 (31 October 2001) --- Backdropped by the blackness of space, a Soyuz spacecraft departs from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the Soyuz carrying the Taxi crew after undocking taken during Expedition Three

NASA Image and Video Library

2001-10-31

ISS003-E-7096 (31 October 2001) --- A Soyuz spacecraft departs from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the Soyuz carrying the Taxi crew after undocking taken during Expedition Three

NASA Image and Video Library

2001-10-31

ISS003-E-7101 (31 October 2001) --- A Soyuz spacecraft departs from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the Soyuz carrying the Taxi crew after undocking taken during Expedition Three

NASA Image and Video Library

2001-10-31

ISS003-E-7094 (31 October 2001) --- A Soyuz spacecraft departs from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the Soyuz carrying the Taxi crew after undocking taken during Expedition Three

NASA Image and Video Library

2001-10-31

ISS003-E-7100 (31 October 2001) --- A Soyuz spacecraft departs from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the Soyuz carrying the Taxi crew after undocking taken during Expedition Three

NASA Image and Video Library

2001-10-31

ISS003-E-7097 (31 October 2001) --- A Soyuz spacecraft departs from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the Soyuz carrying the Taxi crew after undocking taken during Expedition Three

NASA Image and Video Library

2001-10-31

ISS003-E-7107 (31 October 2001) --- A Soyuz spacecraft departs from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

Personal exposures to airborne metals in London taxi drivers and office workers in 1995 and 1996.

PubMed

Pfeifer, G D; Harrison, R M; Lynam, D R

1999-09-01

In 1995, a petroleum marketer introduced a diesel fuel additive in the UK containing Mn as MMT (methylcyclopentadienyl manganese tricarbonyl). A small study of personal exposures to airborne Mn in London was conducted before and after introduction of the additive to identify any major impact of the additive on exposures. In 1995, personal exposures to Mn were measured in two groups, taxi drivers and office workers (10 subjects per group) for two consecutive 7-day periods. A similar study was carried out in 1996 to determine if exposures had changed. Samples were also analyzed for Ca, Al, Mg and Pb. In 1996, exposures to aerosol mass as total suspended particulates (TSP) and PM2.5 were measured in addition to the metals. Manganese exposures in this cohort did not increase as a result of introduction of the additive. However, a significant source of Mn exposure was discovered during the conduct of these tests. The mean exposure to Mn was higher among the office workers in both years than that of the taxi drivers. This was due to the fact that approximately half of the office workers commuted via the underground railway system where airborne dust and metal concentrations are significantly elevated over those in the general environment. Similar results have been noted in other cities having underground rail systems. Exposure to Mn, Pb, Ca, and Mg were not significantly different between the 2 years. Taxi drivers had higher exposures than office workers to Mg and Pb in both years. Commuting via the underground also had a significant impact on exposures to TSP, PM2.5, Al, and Ca, but had little effect on exposures to Mg. The aerosol in the underground was particularly enriched in Mn, approximately 10-fold, when compared to the aerosol in the general environment. There are several possible sources for this Mn, including mechanical wear of the steel wheels on the steel rais, vaporization of metal from sparking of the third rail, or brake wear.

A bipartite graph of Neuroendocrine System

NASA Astrophysics Data System (ADS)

Guo, Zhong-Wei; Zou, Sheng-Rong; Peng, Yu-Jing; Zhou, Ta; Gu, Chang-Gui; He, Da-Ren

2008-03-01

We present an empirical investigation on the neuroendocrine system and suggest describe it by a bipartite graph. In the net the cells can be regarded as collaboration acts and the mediators can be regarded as collaboration actors. The act degree stands for the number of the cells that secrete a single mediator. Among them bFGF (the basic fibroblast growth factor) has the largest node act degree. It is the most important mitogenic cytokine, followed by TGF-beta, IL-6, IL1-beta, VEGF, IGF-1and so on. They are critical in neuroendocrine system to maintain bodily healthiness, emotional stabilization and endocrine harmony. The act degree distribution shows a shifted power law (SPL) function forms [1]. The average act degree of neuroendocrine network is h=3.01, It means that each mediator is secreted by three cells on average. The similarity, which stands for the average probability of secreting the same mediators by all neuroendocrine cells, is observed as s=0.14. Our results may be used in the research of the medical treatment of neuroendocrine diseases. [1] Assortativity and act degree distribution of some collaboration networks, Hui Chang, Bei-Bei Su, Yue-Ping Zhou, Daren He, Physica A, 383 (2007) 687-702

X-Wing RSRA - 80 Knot Taxi Test

NASA Technical Reports Server (NTRS)

1987-01-01

The Rotor Systems Research Aircraft/X-Wing, a vehicle that was used to demonstrate an advanced rotor/fixed wing concept called X-Wing, is shown here during high-speed taxi tests at NASA's Ames-Dryden Flight Research Facility (later redesignated Dryden Flight Research Center), Edwards, California, on 4 November 1987. During these tests, the vehicle made three taxi tests at speeds of up to 138 knots. On the third run, the RSRA/X-Wing lifted off the runway to a 25-foot height for about 16 seconds. This liftoff maneuver was pre-planned as an aid to evaluations for first flight. At the controls were NASA pilot G. Warren Hall and Sikorsky pilot W. Faull. The unusual aircraft that resulted from the Ames Research Center/Army X-Wing Project was flown at the Ames-Dryden Flight Research Facility (now Dryden Flight Research Center), Edwards, California, beginning in the spring of 1984, with a follow-on program beginning in 1986. The program, was conceived to provide an efficient combination of the vertical lift characteristic of conventional helicopters and the high cruise speed of fixed-wing aircraft. It consisted of a hybrid vehicle called the NASA/Army Rotor Systems Research Aircraft (RSRA), which was equipped with advanced X-wing rotor systems. The program began in the early 1970s to investigate ways to increase the speed of rotor aircraft, as well as their performance, reliability, and safety . It also sought to reduce the noise, vibration, and maintenance costs of helicopters. Sikorsky Aircraft Division of United Technologies Laboratories built two RSRA aircraft. NASA's Langley Research Center, Hampton, Virginia, did some initial testing and transferred the program to Ames Research Center, Mountain View, California, for an extensive flight research program conducted by Ames and the Army. The purpose of the 1984 tests was to demonstrate the fixed-wing capability of the helicopter/airplane hybrid research vehicle and explore its flight envelope and flying qualities. These

Complete genome sequences of two novel bipartite begomoviruses infecting common bean in Cuba.

PubMed

Chang-Sidorchuk, Lidia; González-Alvarez, Heidy; Navas-Castillo, Jesús; Fiallo-Olivé, Elvira; Martínez-Zubiaur, Yamila

2017-05-01

The common bean is a host for a large number of begomoviruses (genus Begomovirus, family Geminiviridae) in the New World. Based on the current taxonomic criteria established for the genus Begomovirus, two new members of this genus infecting common bean (Phaseolus vulgaris) in Cuba are herein reported. The cloned bipartite genomes, composed of DNA-A and DNA-B, showed the typical organization of the New World begomoviruses. We propose the names common bean severe mosaic virus and common bean mottle virus for the new begomovirus species.

Generation of a non-zero discord bipartite state with classical second-order interference.

PubMed

Choi, Yujun; Hong, Kang-Hee; Lim, Hyang-Tag; Yune, Jiwon; Kwon, Osung; Han, Sang-Wook; Oh, Kyunghwan; Kim, Yoon-Ho; Kim, Yong-Su; Moon, Sung

2017-02-06

We report an investigation on quantum discord in classical second-order interference. In particular, we theoretically show that a bipartite state with D = 0.311 of discord can be generated via classical second-order interference. We also experimentally verify the theory by obtaining D = 0.197 ± 0.060 of non-zero discord state. Together with the fact that the nonclassicalities originated from physical constraints and information theoretic perspectives are not equivalent, this result provides an insight to understand the nature of quantum discord.

Spin-1 Dirac-Weyl fermions protected by bipartite symmetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Zeren; School of Physics, Peking University, Beijing 100871; Liu, Zhirong, E-mail: LiuZhiRong@pku.edu.cn

2015-12-07

We propose that bipartite symmetry allows spin-1 Dirac-Weyl points, a generalization of the spin-1/2 Dirac points in graphene, to appear as topologically protected at the Fermi level. In this spirit, we provide methodology to construct spin-1 Dirac-Weyl points of this kind in a given 2D space group and get the classification of the known spin-1 systems in the literature. We also apply the workflow to predict two new systems, P3m1-9 and P31m-15, to possess spin-1 at K/K′ in the Brillouin zone of hexagonal lattice. Their stability under various strains is investigated and compared with that of T{sub 3}, an extensivelymore » studied model of ultracold atoms trapped in optical lattice with spin-1 also at K/K′.« less

Changes in functional connectivity dynamics associated with vigilance network in taxi drivers.

PubMed

Shen, Hui; Li, Zhenfeng; Qin, Jian; Liu, Qiang; Wang, Lubin; Zeng, Ling-Li; Li, Hong; Hu, Dewen

2016-01-01

An increasing number of neuroimaging studies have suggested that the fluctuations of low-frequency resting-state functional connectivity (FC) are not noise but are instead linked to the shift between distinct cognitive states. However, there is very limited knowledge about whether and how the fluctuations of FC at rest are influenced by long-term training and experience. Here, we investigated how the dynamics of resting-state FC are linked to driving behavior by comparing 20 licensed taxi drivers with 20 healthy non-drivers using a sliding window approach. We found that the driving experience could be effectively decoded with 90% (p<0.001) accuracy by the amplitude of low-frequency fluctuations in some specific connections, based on a multivariate pattern analysis technique. Interestingly, the majority of these connections fell within a set of distributed regions named "the vigilance network". Moreover, the decreased amplitude of the FC fluctuations within the vigilance network in the drivers was negatively correlated with the number of years that they had driven a taxi. Furthermore, temporally quasi-stable functional connectivity segmentation revealed significant differences between the drivers and non-drivers in the dwell time of specific vigilance-related transient brain states, although the brain's repertoire of functional states was preserved. Overall, these results suggested a significant link between the changes in the time-dependent aspects of resting-state FC within the vigilance network and long-term driving experiences. The results not only improve our understanding of how the brain supports driving behavior but also shed new light on the relationship between the dynamics of functional brain networks and individual behaviors. Copyright © 2015 Elsevier Inc. All rights reserved.

Association of heart rate variability in taxi drivers with marked changes in particulate air pollution in Beijing in 2008.

PubMed

Wu, Shaowei; Deng, Furong; Niu, Jie; Huang, Qinsheng; Liu, Youcheng; Guo, Xinbiao

2010-01-01

Heart rate variability (HRV), a marker of cardiac autonomic function, has been -associated with particulate matter (PM) air pollution, especially in older patients and those with cardio-vascular diseases. However, the effect of PM exposure on cardiac autonomic function in young, healthy adults has received less attention. We evaluated the relationship between exposure to traffic-related PM with an aerodynamic diameter taxi drivers. Continuous measurements of personal exposure to PM2.5 and ambulatory electrocardiogram monitoring were conducted on 11 young healthy taxi drivers for a 12-hr work shift during their work time (09002100 hr) before, during, and after the Beijing 2008 Olympic Games. Mixed-effects regression models were used to estimate associations between PM2.5 exposure and percent changes in 5-min HRV indices after combining data from the three time periods and controlling for potentially confounding variables. Personal exposures of taxi drivers to PM2.5 changed markedly across the three time -periods. The standard deviation of normal-to-normal (SDNN) intervals decreased by 2.2% [95% confidence interval (CI), 3.8% to 0.6%] with an interquartile range (IQR; 69.5 microg/m3) increase in the 30-min PM2.5 moving average, whereas the low-frequency and high-frequency powers decreased by 4.2% (95% CI, 9.0% to 0.8%) and 6.2% (95% CI, 10.7% to 1.5%), respectively, in association with an IQR increase in the 2-hr PM2.5 moving average. Marked changes in traffic-related PM2.5 exposure were associated with altered cardiac autonomic function in young healthy adults.

The Soyuz Taxi crew pose for a group photo in Zvezda during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-7033 (23-31 October 2001) --- The Soyuz Taxi crewmembers assemble for a group photo in the Zvezda Service Module on the International Space Station (ISS). From the left are Flight Engineer Konstantin Kozeev, Commander Victor Afanasyev, and French Flight Engineer Claudie Haignere. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

Bipartite networks improve understanding of effects of waterbody size and angling method on angler–fish interactions

USGS Publications Warehouse

Chizinski, Christopher J.; Martin, Dustin R.; Shizuka, Daizaburo; Pope, Kevin L.

2018-01-01

Networks used to study interactions could provide insights to fisheries. We compiled data from 27 297 interviews of anglers across waterbodies that ranged in size from 1 to 12 113 ha. Catch rates of fish species among anglers grouped by species targeted generally differed between angling methods (bank or boat). We constructed angler–catch bipartite networks (angling method specific) between anglers and fish and measured several network metrics. There was considerable variation in networks among waterbodies, with multiple metrics influenced by waterbody size. Number of species-targeting angler groups and number of fish species caught increased with increasing waterbody size. Mean number of links for species-targeting angler groups and fish species caught also increased with waterbody size. Connectance (realized proportion of possible links) of angler–catch interaction networks decreased slower for boat anglers than for bank anglers with increasing waterbody size. Network specialization (deviation of number of interactions from expected) was not significantly related to waterbody size or angling methods. Application of bipartite networks in fishery science requires careful interpretation of outputs, especially considering the numerous confounding factors prevalent in recreational fisheries.

Maximal violation of a bipartite three-setting, two-outcome Bell inequality using infinite-dimensional quantum systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pal, Karoly F.; Vertesi, Tamas

2010-08-15

The I{sub 3322} inequality is the simplest bipartite two-outcome Bell inequality beyond the Clauser-Horne-Shimony-Holt (CHSH) inequality, consisting of three two-outcome measurements per party. In the case of the CHSH inequality the maximal quantum violation can already be attained with local two-dimensional quantum systems; however, there is no such evidence for the I{sub 3322} inequality. In this paper a family of measurement operators and states is given which enables us to attain the maximum quantum value in an infinite-dimensional Hilbert space. Further, it is conjectured that our construction is optimal in the sense that measuring finite-dimensional quantum systems is not enoughmore » to achieve the true quantum maximum. We also describe an efficient iterative algorithm for computing quantum maximum of an arbitrary two-outcome Bell inequality in any given Hilbert space dimension. This algorithm played a key role in obtaining our results for the I{sub 3322} inequality, and we also applied it to improve on our previous results concerning the maximum quantum violation of several bipartite two-outcome Bell inequalities with up to five settings per party.« less

Bipartite discrimination of independently prepared quantum states as a counterexample to a parallel repetition conjecture

NASA Astrophysics Data System (ADS)

Akibue, Seiseki; Kato, Go

2018-04-01

For distinguishing quantum states sampled from a fixed ensemble, the gap in bipartite and single-party distinguishability can be interpreted as a nonlocality of the ensemble. In this paper, we consider bipartite state discrimination in a composite system consisting of N subsystems, where each subsystem is shared between two parties and the state of each subsystem is randomly sampled from a particular ensemble comprising the Bell states. We show that the success probability of perfectly identifying the state converges to 1 as N →∞ if the entropy of the probability distribution associated with the ensemble is less than 1, even if the success probability is less than 1 for any finite N . In other words, the nonlocality of the N -fold ensemble asymptotically disappears if the probability distribution associated with each ensemble is concentrated. Furthermore, we show that the disappearance of the nonlocality can be regarded as a remarkable counterexample of a fundamental open question in theoretical computer science, called a parallel repetition conjecture of interactive games with two classically communicating players. Measurements for the discrimination task include a projective measurement of one party represented by stabilizer states, which enable the other party to perfectly distinguish states that are sampled with high probability.

Availability, functionality, and use of seat belts in Beijing taxis prior to the 2008 Beijing Olympic Games.

PubMed

Fleiter, Judy J; Gao, Liping; Qiu, Chen; Shi, Kan

2009-03-01

Use of driver seat belts and availability and functionality of passenger seat belts in a convenience sample of 231 Beijing taxis were examined in the months prior to the 2008 Beijing Olympic Games. Driver and front passenger seat belt use was mandated in China from 2004 to help address the growing public health crisis of road trauma. Results from observations made by in-vehicle passengers revealed that 21.2% of drivers were correctly wearing a belt, approximately half were not, and one third were using the belt in a non-functional way. Over 3/4 of this sample of taxi drivers were unrestrained while working. The percentage of functionally available belts was higher for front than rear passengers (88.3% and 22.9%, respectively). This low rate of belt availability in rear seats calls into question the preparedness of the fleet to cater for the safety needs of foreign visitors to China, particularly those from countries with high levels of restraint use. Factors influencing the use/misuse of seat belts in China remain largely unexplored. Results of this pilot study support further investigations of barriers to using injury prevention mechanisms such as seat belts in less motorised countries.

View of the approach of the Soyuz carrying the Taxi crew taken during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-6840 (23 October 2001) --- A Soyuz spacecraft approaches the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere for an eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the approach of the Soyuz carrying the Taxi crew taken during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-6849 (23 October 2001) --- A Soyuz spacecraft approaches the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere for an eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the approach of the Soyuz carrying the Taxi crew taken during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-6851 (23 October 2001) --- A Soyuz spacecraft approaches the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere for an eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the approach of the Soyuz carrying the Taxi crew taken during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-6841 (23 October 2001) --- A Soyuz spacecraft approaches the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere for an eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the approach of the Soyuz carrying the Taxi crew taken during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-6847 (23 October 2001) --- A Soyuz spacecraft approaches the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere for an eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the approach of the Soyuz carrying the Taxi crew taken during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-6844 (23 October 2001) --- A Soyuz spacecraft approaches the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere for an eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the approach of the Soyuz carrying the Taxi crew taken during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-6845 (23 October 2001) --- A Soyuz spacecraft approaches the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere for an eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

View of the approach of the Soyuz carrying the Taxi crew taken during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-6850 (23 October 2001) --- A Soyuz spacecraft approaches the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere for an eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

Association of Heart Rate Variability in Taxi Drivers with Marked Changes in Particulate Air Pollution in Beijing in 2008

PubMed Central

Wu, Shaowei; Deng, Furong; Niu, Jie; Huang, Qinsheng; Liu, Youcheng; Guo, Xinbiao

2010-01-01

Background Heart rate variability (HRV), a marker of cardiac autonomic function, has been associated with particulate matter (PM) air pollution, especially in older patients and those with cardiovascular diseases. However, the effect of PM exposure on cardiac autonomic function in young, healthy adults has received less attention. Objectives We evaluated the relationship between exposure to traffic-related PM with an aerodynamic diameter ≤ 2.5 μm (PM2.5) and HRV in a highly exposed panel of taxi drivers. Methods Continuous measurements of personal exposure to PM2.5 and ambulatory electrocardiogram monitoring were conducted on 11 young healthy taxi drivers for a 12-hr work shift during their work time (0900–2100 hr) before, during, and after the Beijing 2008 Olympic Games. Mixed-effects regression models were used to estimate associations between PM2.5 exposure and percent changes in 5-min HRV indices after combining data from the three time periods and controlling for potentially confounding variables. Results Personal exposures of taxi drivers to PM2.5 changed markedly across the three time periods. The standard deviation of normal-to-normal (SDNN) intervals decreased by 2.2% [95% confidence interval (CI), −3.8% to −0.6%] with an interquartile range (IQR; 69.5 μg/m3) increase in the 30-min PM2.5 moving average, whereas the low-frequency and high-frequency powers decreased by 4.2% (95% CI, −9.0% to 0.8%) and 6.2% (95% CI, −10.7% to −1.5%), respectively, in association with an IQR increase in the 2-hr PM2.5 moving average. Conclusions Marked changes in traffic-related PM2.5 exposure were associated with altered cardiac autonomic function in young healthy adults. PMID:20056565

Effect of free distribution of safety equipment on usage among motorcycle-taxi drivers in Tanzania--A cluster randomised controlled trial.

PubMed

Sumner, Steven A; Pallangyo, Anthony J; Reddy, Elizabeth A; Maro, Venance; Pence, Brian W; Lynch, Catherine; Turner, Elizabeth L; Egger, Joseph R; Thielman, Nathan M

2014-11-01

Deaths due to road traffic injuries, particularly motorcycle crashes, have increased rapidly in many African nations and context-specific strategies to improve preventative behaviours are needed. Although adhering to conspicuity measures by wearing reflective safety vests is a highly effective crash prevention strategy and mandated by law among motorcycle-taxi drivers in some African countries, actual use is currently low. We aimed to test whether eliminating cost-barriers through the provision of free reflective, fluorescent motorcycle safety vests would lead to increased utilisation among a high-risk population of motorcycle-taxi drivers in Tanzania. A cluster randomised controlled trial was conducted among 180 motorcycle-taxi drivers. Participants randomised to the intervention arm (90) received free, reflective, fluorescent vests; participants randomised to the control arm (90) did not receive free vests. Participants' use of reflective vests was then observed on city streets over a three month period and differential uptake was estimated using mixed-effects logistic regression. Baseline use of reflective vests was 3.3% in both arms. Seventy-nine drivers in the intervention arm and 82 drivers in the control arm were observed during follow-up. The average proportion of observations during which motorcycle drivers were using a reflective vest was 9.5% in the intervention arm, compared to 2.0% in the control arm (odds ratio: 5.5, 95% confidence interval: 1.1-26.9, p-value: 0.04). Although distribution of free reflective vests led to a statistically significant increase in vest usage, the absolute increase was modest. Additional strategies beyond removing economic barriers are important to augment adherence to road safety behaviours for injury prevention. Copyright © 2014 Elsevier Ltd. All rights reserved.

Forbidden regimes in the distribution of bipartite quantum correlations due to multiparty entanglement

NASA Astrophysics Data System (ADS)

Kumar, Asutosh; Dhar, Himadri Shekhar; Prabhu, R.; Sen(De), Aditi; Sen, Ujjwal

2017-05-01

Monogamy is a nonclassical property that limits the distribution of quantum correlation among subparts of a multiparty system. We show that monogamy scores for different quantum correlation measures are bounded above by functions of genuine multipartite entanglement for a large majority of pure multiqubit states. The bound is universal for all three-qubit pure states. We derive necessary conditions to characterize the states that violate the bound, which can also be observed by numerical simulation for a small set of states, generated Haar uniformly. The results indicate that genuine multipartite entanglement restricts the distribution of bipartite quantum correlations in a multiparty system.

Boundedness and global stability of the two-predator and one-prey models with nonlinear prey-taxis

NASA Astrophysics Data System (ADS)

Wang, Jianping; Wang, Mingxin

2018-06-01

This paper concerns the reaction-diffusion systems modeling the population dynamics of two predators and one prey with nonlinear prey-taxis. We first investigate the global existence and boundedness of the unique classical solution for the general model. Then, we study the global stabilities of nonnegative spatially homogeneous equilibria for an explicit system with type I functional responses and density-dependent death rates for the predators and logistic growth for the prey. Moreover, the convergence rates are also established.

Template Recognition Mechanisms by Replicase Proteins Differ between Bipartite Positive-Strand Genomic RNAs of a Plant Virus▿

PubMed Central

Iwakawa, Hiro-oki; Mine, Akira; Hyodo, Kiwamu; An, Mengnan; Kaido, Masanori; Mise, Kazuyuki; Okuno, Tetsuro

2011-01-01

Recognition of RNA templates by viral replicase proteins is one of the key steps in the replication process of all RNA viruses. However, the mechanisms underlying this phenomenon, including primary RNA elements that are recognized by the viral replicase proteins, are not well understood. Here, we used aptamer pulldown assays with membrane fractionation and protein-RNA coimmunoprecipitation in a cell-free viral translation/replication system to investigate how viral replicase proteins recognize the bipartite genomic RNAs of the Red clover necrotic mosaic virus (RCNMV). RCNMV replicase proteins bound specifically to a Y-shaped RNA element (YRE) located in the 3′ untranslated region (UTR) of RNA2, which also interacted with the 480-kDa replicase complexes that contain viral and host proteins. The replicase-YRE interaction recruited RNA2 to the membrane fraction. Conversely, RNA1 fragments failed to interact with the replicase proteins supplied in trans. The results of protein-RNA coimmunoprecipitation assays suggest that RNA1 interacts with the replicase proteins coupled with their translation. Thus, the initial template recognition mechanisms employed by the replicase differ between RCNMV bipartite genomic RNAs and RNA elements are primary determinants of the differential replication mechanism. PMID:20980498

Random bipartite entanglement from W and W-like states.

PubMed

Fortescue, Ben; Lo, Hoi-Kwong

2007-06-29

We describe a protocol for distilling maximally entangled bipartite states between random pairs of parties from those sharing a tripartite W state |W=(1/sqrt[3])(|100+|010+|001)(ABC), and show that the total distillation rate E(t)(infinity) [the total number of Einstein-Podolsky-Rosen (EPR) pairs distilled per W, irrespective of who shares them] may be done at a higher rate than EPR distillation between specified pairs of parties. Specifically, the optimal rate for distillation to specified parties has been previously shown to be 0.92 EPR pairs per W, while our protocol can asymptotically distill 1 EPR pair per W between random pairs of parties, which we conjecture to be optimal. We thus demonstrate a tradeoff between overall distillation rate and final distribution of EPR pairs. We further show that there exist states with fixed lower-bounded E(t)(infinity), but arbitrarily small distillable entanglement for specified parties.

No-signaling, perfect bipartite dichotomic correlations and local randomness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seevinck, M. P.

2011-03-28

The no-signaling constraint on bi-partite correlations is reviewed. It is shown that in order to obtain non-trivial Bell-type inequalities that discern no-signaling correlations from more general ones, one must go beyond considering expectation values of products of observables only. A new set of nontrivial no-signaling inequalities is derived which have a remarkably close resemblance to the CHSH inequality, yet are fundamentally different. A set of inequalities by Roy and Singh and Avis et al., which is claimed to be useful for discerning no-signaling correlations, is shown to be trivially satisfied by any correlation whatsoever. Finally, using the set of newlymore » derived no-signaling inequalities a result with potential cryptographic consequences is proven: if different parties use identical devices, then, once they have perfect correlations at spacelike separation between dichotomic observables, they know that because of no-signaling the local marginals cannot but be completely random.« less

All pure bipartite entangled states can be self-tested

PubMed Central

Coladangelo, Andrea; Goh, Koon Tong; Scarani, Valerio

2017-01-01

Quantum technologies promise advantages over their classical counterparts in the fields of computation, security and sensing. It is thus desirable that classical users are able to obtain guarantees on quantum devices, even without any knowledge of their inner workings. That such classical certification is possible at all is remarkable: it is a consequence of the violation of Bell inequalities by entangled quantum systems. Device-independent self-testing refers to the most complete such certification: it enables a classical user to uniquely identify the quantum state shared by uncharacterized devices by simply inspecting the correlations of measurement outcomes. Self-testing was first demonstrated for the singlet state and a few other examples of self-testable states were reported in recent years. Here, we address the long-standing open question of whether every pure bipartite entangled state is self-testable. We answer it affirmatively by providing explicit self-testing correlations for all such states. PMID:28548093

All pure bipartite entangled states can be self-tested

NASA Astrophysics Data System (ADS)

Coladangelo, Andrea; Goh, Koon Tong; Scarani, Valerio

2017-05-01

Quantum technologies promise advantages over their classical counterparts in the fields of computation, security and sensing. It is thus desirable that classical users are able to obtain guarantees on quantum devices, even without any knowledge of their inner workings. That such classical certification is possible at all is remarkable: it is a consequence of the violation of Bell inequalities by entangled quantum systems. Device-independent self-testing refers to the most complete such certification: it enables a classical user to uniquely identify the quantum state shared by uncharacterized devices by simply inspecting the correlations of measurement outcomes. Self-testing was first demonstrated for the singlet state and a few other examples of self-testable states were reported in recent years. Here, we address the long-standing open question of whether every pure bipartite entangled state is self-testable. We answer it affirmatively by providing explicit self-testing correlations for all such states.

All pure bipartite entangled states can be self-tested.

PubMed

Coladangelo, Andrea; Goh, Koon Tong; Scarani, Valerio

2017-05-26

Quantum technologies promise advantages over their classical counterparts in the fields of computation, security and sensing. It is thus desirable that classical users are able to obtain guarantees on quantum devices, even without any knowledge of their inner workings. That such classical certification is possible at all is remarkable: it is a consequence of the violation of Bell inequalities by entangled quantum systems. Device-independent self-testing refers to the most complete such certification: it enables a classical user to uniquely identify the quantum state shared by uncharacterized devices by simply inspecting the correlations of measurement outcomes. Self-testing was first demonstrated for the singlet state and a few other examples of self-testable states were reported in recent years. Here, we address the long-standing open question of whether every pure bipartite entangled state is self-testable. We answer it affirmatively by providing explicit self-testing correlations for all such states.

Factors associated with drug use among male motorbike taxi drivers in urban Vietnam.

PubMed

Nguyen, Huy Van; Vu, Thinh Toan; Pham, Ha Nguyen

2014-08-01

A cross-sectional study was conducted on a sample of 291 male motorbike taxi drivers (MMTDs) recruited through social mapping technique in Hanoi, Vietnam, for face-to-face interviews to examine factors associated with drug use among MMTDs using Information-Motivation-Behavioral skills (IMB) model. Among 291 MMTDs, 17.18% reported drug use sometime in their lives, 96% of whom were drug injectors. Being depressed, being originally borne in urban cities, currently residing in rural areas, having a longer time living apart from their wives/lovers, using alcohol, following Buddhism, and reporting lower motivation of HIV prevention predict significantly higher odds of uptaking drugs.

View of the Soyuz carrying the Taxi crew during undocking from the ISS

NASA Image and Video Library

2001-10-31

ISS003-E-7118 (31 October 2001) --- A Soyuz spacecraft, backdropped by Earth’s horizon and the blackness of space, is photographed prior to departure from the International Space Station (ISS), carrying the Soyuz taxi crew back to Earth, ending their eight-day stay on the station. The crewmembers are Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

MLF1-interacting protein is mainly localized in nucleolus through N-terminal bipartite nuclear localization signal.

PubMed

Suzuki, Hideaki; Arakawa, Yasuhiro; Ito, Masaki; Saito, Shinobu; Takeda, Nobuakira; Yamada, Hisashi; Horiguchi-Yamada, Junko

2007-01-01

The myelodysplasia/myeloid leukemia factor 1-interacting protein (MLF1LP, also called KLIP1 and CENP-50) is reported to localize in both the nucleus and the cytoplasm. To investigate the functions of MLF1IP, its subnuclear localization was studied. MLF1IP was tagged with green fluorescent protein (EGFP). Fibrillarin was tagged with red fluorescent protein (DsRed). EGFP-tagged MLF1IP deletion vectors were also constructed. Plasmid-constructs were transfected into human cervical adenocarcinoma HeLa cells or monkey kidney fibroblast COS-7 cells, and the localization was studied by either confocal fluorescence microscopy or fluorescence microscopy. Ectopically expressed MLF1IP was localized mainly in the nucleolus. In some cells, small dot-like particles of MLF1IP fluorescence were observed in the nucleoplasm. Co-staining of fibrillarin disclosed that MLF1IP was co-localized with fibrillarin in the nucleolus. Deletion mutants of MLF1IP revealed that the N-terminal bipartite nuclear localization signal (NLS) was responsible for nucleolar targeting. MLF1IP was localized mainly in the nucleolus through the N-terminal bipartite NLS and partly in the nucleoplasm featuring small dot-like particles. These findings suggest that MLF1IP may have multi-functions and its different localizations may contribute to carcinogenesis.

Human Mars Mission: SEP Architecture Crew Taxi Propulsion Stage Study and Design and Technology for Reaction and Control System. Part 1

NASA Technical Reports Server (NTRS)

Young, Archie

1999-01-01

The Mars exploration is a candidate pathway to expand human presence and useful activities in the solar system. There are several propulsion system options being considered to place the Mars payload on its inter-planetary transfer trajectory. One propulsion option is the use of Solar Electric Propulsion (SEP) to spiral out with the Mars payload from an initial Low Earth Orbit (LEO) to an elliptical High Earth Orbit (HEO). This report, presented in annotated facing page format, describes the work completed on the design of a crew taxi propulsion stage used in conjunction with the SEP. Transportation system/mission analysis topics covered in this report include sub-system analysis, trajectory profile description, mass performance and crew taxi stage sizing, stage configuration, stage cost, and Trans-Mars Injection (TMI) launch window. The high efficiency of SEP is used to provide the major part of the TMI propulsion maneuver. Orbital energy is continuously added over a period of approximately twelve months. The SEP and Mars payload follow a spiral trajectory from an initial LEO to a final elliptical HEO. A small chemical stage is then used to provide the final part of the TMI. The now unloaded SEP returns to LEO to repeat another spiral trajectory with payload to HEO. The spiral phase of the SEP's trajectory takes several months to reach HEO, thus significantly increasing the exposure time of the crew to zero-gravity. In order to minimize the long zero-gravity effects, a high thrust chemical stage delivers the crew to the SEP's HEO. The crew rendezvous with the Mars payload in HEO. After a checkout period the Mars payload with the crew is injected onto a Trans-Mars Trajectory by a small chemical stage.

Human Mars Mission: SEP Architecture, Crew Taxi Propulsion Stage Study and Design and Technology for Reaction and Control System. Pt. 1

NASA Technical Reports Server (NTRS)

Young, Archie

1999-01-01

The Mars exploration is a candidate pathway to expand human presence and useful activities in the solar system. There are several propulsion system options being considered to place the Mars payload on its interplanetary transfer trajectory. One propulsion option is the use of Solar Electric Propulsion (SEP) to spiral out with the Mars payload from an initial Low Earth Orbit (LEO) to an elliptical High Earth Orbit (HEO). This report, presented in annotated facing page format, describes the work completed on the design of a crew taxi propulsion stage used in conjunction with the SEP. Transportation system/mission analysis topics covered in this report include sub-system analysis, trajectory profile description, mass performance and crew taxi stage sizing, stage configuration, stage cost, and Trans-Mars Injection (TMI) launch window. The high efficiency of SEP is used to provide the major part of the TMI propulsion maneuver. Orbital energy is continuously added over a period of approximately twelve months. The SEP and Mars payload follow a spiral trajectory from an initial LEO to a final elliptical HEO. A small chemical stage is then used to provide the final part of the TMI. The now unloaded SEP returns to LEO to repeat another spiral trajectory with payload to HEO. The spiral phase of the SEP's trajectory takes several months to reach HEO, thus significantly increasing the exposure time of the crew to zero-gravity. In order to minimize the long zero-gravity effects, a high thrust chemical stage delivers the crew to the SEP's HEO. The crew rendezvous with the Mars payload in HEO. After a checkout period the Mars payload with the crew is injected onto a Trans-Mars Trajectory by a small chemical stage.

Determining of the Parking Manoeuvre and the Taxi Blockage Adjustment Factor for the Saturation Flow Rate at the Outlet Legs of Signalized Intersections: Case Study from Rasht City (Iran)

NASA Astrophysics Data System (ADS)

Behbahani, Hamid; Jahangir Samet, Mehdi; Najafi Moghaddam Gilani, Vahid; Amini, Amir

2017-10-01

The presence of taxi stops within the area of signalized intersections at the outlet legs due to unnatural behaviour of the taxis, sudden change of lanes, parking manoeuvres activities and stopping the vehicle to discharge or pick up the passengers have led to reduction of saturation flow rate at the outlet leg of signalized intersections and increased delay as well as affecting the performance of a crossing lane. So far, in term of evaluating effective adjustment factors on saturation flow rate at the inlet legs of the signalized intersections, various studies have been carried out, however; there has not been any studies on effective adjustment factors on saturation flow rate at the inlet legs. Hence, the evaluating of the traffic effects of unique behaviours on the saturation flow rate of the outlet leg is very important. In this research the parking manoeuvre time and taxi blockage time were evaluated and analyzed based on the available lane width as well as determining the effective adjustment factors on the saturation flow rate using recording related data at four signalized intersections in Rasht city. The results show that the average parking manoeuvre time is a function of the lane width and is increased as the lane width is reduced. Also, it is suggested to use the values of 7.37 and 11.31 seconds, respectively for the average parking manoeuvre time and the average blockage time of taxies at the outlet legs of signalized intersections for the traffic designing in Rasht city.

Exposures to PM₂.₅ components and heart rate variability in taxi drivers around the Beijing 2008 Olympic Games.

PubMed

Wu, Shaowei; Deng, Furong; Niu, Jie; Huang, Qinsheng; Liu, Youcheng; Guo, Xinbiao

2011-06-01

Carbonaceous and metallic components of particles have been shown to play a role in particles' effects on cardiac autonomic function as measured by heart rate variability (HRV). Previously we reported the association of HRV with marked changes in traffic-related particulate air pollution around the Beijing 2008 Olympic Games in a panel of taxi drivers. We further investigated the relationship between exposures to the carbonaceous and metallic components of traffic-related particles and HRV in the same population. Repeated measurements of in-car exposures to particulate matter ≤ 2.5 μm in aerodynamic diameter (PM₂.₅), carbon monoxide and nitrogen oxides were conducted in a group of 14 taxi drivers for one work shift in four study periods around the Beijing 2008 Olympics. The quantities of organic/elemental carbons and 27 elements of the in-car PM₂.₅ mass were determined laboratorially. Linear mixed-effects models were used to evaluate the impact of exposures to different PM₂.₅ components on HRV while controlling for potential confounders. Taxi drivers' exposures to in-car PM₂.₅ and its components showed dramatic changes across the four study periods around the Beijing 2008 Olympics. Differences in associations of in-car PM₂.₅ components with HRV were found. An interquartile range (IQR: 917.9 ng/m³) increase in calcium was associated with a 5.48 millisecond [ms, 95% confidence interval (CI): 0.71, 10.24] increase in standard deviations of normal-to-normal (SDNN) intervals, while an IQR (4.1 ng/m³) increase in nickel was associated with a 1.53 ms (95% CI: 0.14, 2.92) increase in SDNN index. Additionally, a decline of 8.11 ms (95% CI: -15.26, -0.97) in SDNN per IQR (481.4 ng/m³) increase in iron was also found. The results support associations of PM₂.₅ metallic components with HRV in younger healthy individuals. Future studies are needed to clarify the interaction among different PM₂.₅ components or the role of PM₂.₅ mixtures

Distant view of the Soyuz carrying the Taxi crew after undocking from the ISS

NASA Image and Video Library

2001-10-31

ISS003-E-7131 (31 October 2001) --- Backdropped by Earth’s horizon and the blackness of space, this distant view shows a Soyuz spacecraft after undocking from the International Space Station (ISS) carrying the Soyuz taxi crew, Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere, ending their eight-day stay on the station. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

Bipartite Community Structure of eQTLs.

PubMed

Platig, John; Castaldi, Peter J; DeMeo, Dawn; Quackenbush, John

2016-09-01

Genome Wide Association Studies (GWAS) and expression quantitative trait locus (eQTL) analyses have identified genetic associations with a wide range of human phenotypes. However, many of these variants have weak effects and understanding their combined effect remains a challenge. One hypothesis is that multiple SNPs interact in complex networks to influence functional processes that ultimately lead to complex phenotypes, including disease states. Here we present CONDOR, a method that represents both cis- and trans-acting SNPs and the genes with which they are associated as a bipartite graph and then uses the modular structure of that graph to place SNPs into a functional context. In applying CONDOR to eQTLs in chronic obstructive pulmonary disease (COPD), we found the global network "hub" SNPs were devoid of disease associations through GWAS. However, the network was organized into 52 communities of SNPs and genes, many of which were enriched for genes in specific functional classes. We identified local hubs within each community ("core SNPs") and these were enriched for GWAS SNPs for COPD and many other diseases. These results speak to our intuition: rather than single SNPs influencing single genes, we see groups of SNPs associated with the expression of families of functionally related genes and that disease SNPs are associated with the perturbation of those functions. These methods are not limited in their application to COPD and can be used in the analysis of a wide variety of disease processes and other phenotypic traits.

Bipartite non-classical correlations for a lossy two connected qubit-cavity systems: trace distance discord and Bell's non-locality

NASA Astrophysics Data System (ADS)

Mohamed, Abdel-Baset A.

2018-04-01

In this paper, some non-classical correlations are investigated for bipartite partitions of two qubits trapped in two spatially separated cavities connected by an optical fiber. The results show that the trace distance discord and Bell's non-locality introduce other quantum correlations beyond the entanglement. Moreover, the correlation functions of the trace distance discord and the Bell's non-locality are very sensitive to the initial correlations, the coupling strengths, and the dissipation rates of the cavities. The fluctuations of the correlation functions between their initial values and gained (loss) values appear due to the unitary evolution of the system. These fluctuations depend on the chosen initial correlations between the two subsystems. The maximal violations of Bell's inequality occur when the logarithmic negativity and the trace distance discord reach certain values. It is shown that the robustness of the non-classical correlations, against the dissipation rates of the cavities, depends on the bipartite partitions reduced density matrices of the system, and is also greatly enhanced by choosing appropriate coupling strengths.

Occupational and personal factors associated with acquired lumbar spondylolisthesis of urban taxi drivers

PubMed Central

Chen, J; Chan, W; Katz, J; Chang, W; Christiani, D

2004-01-01

Aims: To investigate the occupational and personal factors associated with lumbar spondylolisthesis in taxi drivers. Methods: Cross-sectional analysis of the baseline data from the Taxi Drivers' Health Study cohort. Information was retrieved from the medical records of standardised lumbosacral spine plain films, age, and anthropometric measures of 1242 subjects. Acquired spondylolisthesis (ASL) was defined as non-lytic spondylolisthesis involving lumbar spines above L5. Questionnaires were used to gather information on demographic features, health behaviours, exercise, work related physical and psychosocial factors, and driving time profiles. Multiple logistic regression was used to model the odds ratio (OR) for prevalent ASL cases associated with personal and occupational factors. Results: A total of 40 cases (3.2%) of ASL were diagnosed. Among those driving ⩽5 years, 6–15 years, and >15 years, the estimated prevalence of lumbar spondylolisthesis was 1.1%, 2.4%, and 7.1% respectively. Results of multiple logistic regression suggested that taxicab driving >15 years (OR = 3.4, 95% CI 1.1 to 10.7, compared to driving ⩽5 years), age (OR = 2.6, 95% CI 1.1 to 6.6 for age 46–55; and OR = 4.8, 95% CI 1.8 to 12.9 for age >55), body mass index ⩾25 kg/m2 (OR = 2.2, 95% CI 1.1 to 4.6), and frequent strenuous exercise (OR = 2.2, 95% CI 1.1 to 4.5) were significantly associated with higher prevalence of spondylolisthesis. There was a consistent likely exposure-response relation between professional seniority and ASL prevalence. Conclusions: Longitudinal studies are needed to confirm the observed association between professional driving and spondylolisthesis, and to examine further the specific occupational exposures accountable for this association. PMID:15550605

Effects of diffusion in competitive contact processes on bipartite lattices

NASA Astrophysics Data System (ADS)

de Oliveira, M. M.; Fiore, C. E.

2017-05-01

We investigate the influence of particle diffusion in the two-dimension contact process (CP) with a competitive dynamics in bipartite sublattices, proposed in de Oliveira and Dickman (2011 Phys. Rev. E 84 011125). The particle creation depends on its first and second neighbors and the extinction increases according to the local density. In contrast to the standard CP model, mean-field theory and numerical simulations predict three stable phases: inactive (absorbing), active symmetric and active asymmetric, signed by distinct sublattice particle occupations. Our results from MFT and Monte Carlo simulations reveal that low diffusion rates do not destroy sublattice ordering, ensuring the maintenance of the asymmetric phase. On the other hand, for diffusion larger than a threshold value D c , the sublattice ordering is suppressed and only the usual active (symmetric)-inactive transition is presented. We also show the critical behavior and universality classes are not affected by the diffusion.

Locally indistinguishable orthogonal product bases in arbitrary bipartite quantum system

PubMed Central

Xu, Guang-Bao; Yang, Ying-Hui; Wen, Qiao-Yan; Qin, Su-Juan; Gao, Fei

2016-01-01

As we know, unextendible product basis (UPB) is an incomplete basis whose members cannot be perfectly distinguished by local operations and classical communication. However, very little is known about those incomplete and locally indistinguishable product bases that are not UPBs. In this paper, we first construct a series of orthogonal product bases that are completable but not locally distinguishable in a general m ⊗ n (m ≥ 3 and n ≥ 3) quantum system. In particular, we give so far the smallest number of locally indistinguishable states of a completable orthogonal product basis in arbitrary quantum systems. Furthermore, we construct a series of small and locally indistinguishable orthogonal product bases in m ⊗ n (m ≥ 3 and n ≥ 3). All the results lead to a better understanding of the structures of locally indistinguishable product bases in arbitrary bipartite quantum system. PMID:27503634

GENERAL: Teleportation of a Bipartite Entangled Coherent State via a Four-Partite Cluster-Type Entangled State

NASA Astrophysics Data System (ADS)

Chen, Hui-Na; Liu, Jin-Ming

2009-10-01

We present an optical scheme to almost completely teleport a bipartite entangled coherent state using a four-partite cluster-type entangled coherent state as quantum channel. The scheme is based on optical elements such as beam splitters, phase shifters, and photon detectors. We also obtain the average fidelity of the teleportation process. It is shown that the average fidelity is quite close to unity if the mean photon number of the coherent state is not too small.

Ultracold fermions in a one-dimensional bipartite optical lattice: Metal-insulator transitions driven by shaking

NASA Astrophysics Data System (ADS)

Di Liberto, M.; Malpetti, D.; Japaridze, G. I.; Morais Smith, C.

2014-08-01

We theoretically investigate the behavior of a system of fermionic atoms loaded in a bipartite one-dimensional optical lattice that is under the action of an external time-periodic driving force. By using Floquet theory, an effective model is derived. The bare hopping coefficients are renormalized by zeroth-order Bessel functions of the first kind with different arguments for the nearest-neighbor and next-nearest-neighbor hopping. The insulating behavior characterizing the system at half filling in the absence of driving is dynamically suppressed, and for particular values of the driving parameter the system becomes either a standard metal or an unconventional metal with four Fermi points. The existence of the four-Fermi-point metal relies on the fact that, as a consequence of the shaking procedure, the next-nearest-neighbor hopping coefficients become significant compared to the nearest-neighbor ones. We use the bosonization technique to investigate the effect of on-site Hubbard interactions on the four-Fermi-point metal-insulator phase transition. Attractive interactions are expected to enlarge the regime of parameters where the unconventional metallic phase arises, whereas repulsive interactions reduce it. This metallic phase is known to be a Luther-Emery liquid (spin-gapped metal) for both repulsive and attractive interactions, contrary to the usual Hubbard model, which exhibits a Mott-insulator phase for repulsive interactions. Ultracold fermions in driven one-dimensional bipartite optical lattices provide an interesting platform for the realization of this long-studied four-Fermi-point unconventional metal.

"Dammed Taxi Cab"--How Silent Communication in Questionnaires Can Be Understood and Used to Give Voice to Children's Experiences

ERIC Educational Resources Information Center

Alerby, E.; Kostenius, C.

2011-01-01

"Dammed taxi cab"--a 12-year-old boy wrote these words in the margins of a questionnaire, and within this paper they will serve as a point of departure for the discussion of the use of questionnaires as a way to voice children's experiences. The overall aim of this paper is to enable understanding of and discuss the use of questionnaires as a way…

Large-scale functional brain network changes in taxi drivers: evidence from resting-state fMRI.

PubMed

Wang, Lubin; Liu, Qiang; Shen, Hui; Li, Hong; Hu, Dewen

2015-03-01

Driving a car in the environment is a complex behavior that involves cognitive processing of visual information to generate the proper motor outputs and action controls. Previous neuroimaging studies have used virtual simulation to identify the brain areas that are associated with various driving-related tasks. Few studies, however, have focused on the specific patterns of functional organization in the driver's brain. The aim of this study was to assess differences in the resting-state networks (RSNs) of the brains of drivers and nondrivers. Forty healthy subjects (20 licensed taxi drivers, 20 nondrivers) underwent an 8-min resting-state functional MRI acquisition. Using independent component analysis, three sensory (primary and extrastriate visual, sensorimotor) RSNs and four cognitive (anterior and posterior default mode, left and right frontoparietal) RSNs were retrieved from the data. We then examined the group differences in the intrinsic brain activity of each RSN and in the functional network connectivity (FNC) between the RSNs. We found that the drivers had reduced intrinsic brain activity in the visual RSNs and reduced FNC between the sensory RSNs compared with the nondrivers. The major finding of this study, however, was that the FNC between the cognitive and sensory RSNs became more positively or less negatively correlated in the drivers relative to that in the nondrivers. Notably, the strength of the FNC between the left frontoparietal and primary visual RSNs was positively correlated with the number of taxi-driving years. Our findings may provide new insight into how the brain supports driving behavior. © 2014 Wiley Periodicals, Inc.

Sociodemographic factors associated with aggressive driving behaviors of 3-wheeler taxi drivers in Sri Lanka.

PubMed

Akalanka, Ediriweera Chintana; Fujiwara, Takeo; Desapriya, Ediriweera; Peiris, Dinithi C; Scime, Giulia

2012-01-01

Little is known about the nature and scope of aggressive driving in developing countries. The objective of this study is to specifically examine the sociodemographic factors associated with aggressive driving behavior among 3-wheeler taxi drivers in Sri Lanka. Convenience samples of 3-wheeler taxi drivers from Rathnapura, Ahaliyagoda, Sri Lanka were surveyed from June to August 2006. Analyses included bivariate and multivariate logistic regression. Drivers with less than high school education were 3.5 times more likely to drive aggressively (odds ratio [OR] = 3.46; 95% confidence interval [CI] = 1.08, 11.1). Single drivers were 9 times more likely to run red lights (OR = 8.74; 95% CI = 2.18, 35.0), and being single was a major risk factor for drunk driving (OR = 4.80; 95% CI = 1.23, 18.7). Furthermore, high school completers were 4 times more likely to bribe a policeman (OR = 4.27; 95% CI = 1.23, 14.9) when caught violating the road rules. Aggressive driving and risk-taking behavior are amenable to policy initiatives, and preventive programs targeted at key groups could be used to improve road safety in Sri Lanka. This study demonstrates that aggressive driving behavior is associated with sociodemographic factors, including the level of education, marital status, and other socioeconomic factors. Hence, economic factors should be addressed to find solutions to traffic-related issues. It will be the government's and policy makers' responsibility to try and understand the economic factors behind risky road behavior and bribe-taking behavior prior to legislating or enforcing new laws.

Identifying online user reputation of user-object bipartite networks

NASA Astrophysics Data System (ADS)

Liu, Xiao-Lu; Liu, Jian-Guo; Yang, Kai; Guo, Qiang; Han, Jing-Ti

2017-02-01

Identifying online user reputation based on the rating information of the user-object bipartite networks is important for understanding online user collective behaviors. Based on the Bayesian analysis, we present a parameter-free algorithm for ranking online user reputation, where the user reputation is calculated based on the probability that their ratings are consistent with the main part of all user opinions. The experimental results show that the AUC values of the presented algorithm could reach 0.8929 and 0.8483 for the MovieLens and Netflix data sets, respectively, which is better than the results generated by the CR and IARR methods. Furthermore, the experimental results for different user groups indicate that the presented algorithm outperforms the iterative ranking methods in both ranking accuracy and computation complexity. Moreover, the results for the synthetic networks show that the computation complexity of the presented algorithm is a linear function of the network size, which suggests that the presented algorithm is very effective and efficient for the large scale dynamic online systems.

Generalized bipartite quantum state discrimination problems with sequential measurements

NASA Astrophysics Data System (ADS)

Nakahira, Kenji; Kato, Kentaro; Usuda, Tsuyoshi Sasaki

2018-02-01

We investigate an optimization problem of finding quantum sequential measurements, which forms a wide class of state discrimination problems with the restriction that only local operations and one-way classical communication are allowed. Sequential measurements from Alice to Bob on a bipartite system are considered. Using the fact that the optimization problem can be formulated as a problem with only Alice's measurement and is convex programming, we derive its dual problem and necessary and sufficient conditions for an optimal solution. Our results are applicable to various practical optimization criteria, including the Bayes criterion, the Neyman-Pearson criterion, and the minimax criterion. In the setting of the problem of finding an optimal global measurement, its dual problem and necessary and sufficient conditions for an optimal solution have been widely used to obtain analytical and numerical expressions for optimal solutions. Similarly, our results are useful to obtain analytical and numerical expressions for optimal sequential measurements. Examples in which our results can be used to obtain an analytical expression for an optimal sequential measurement are provided.

Taxi and Expedition Three crews pose for a group photo in Zvezda during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-7036 (23-31 October 2001) --- Astronaut Frank L. Culbertson, Jr. (foreground), Expedition Three mission commander, and the Soyuz Taxi crewmembers assemble for a group photo in the Zvezda Service Module on the International Space Station (ISS). From the left are Flight Engineer Konstantin Kozeev, Commander Victor Afanasyev, and French Flight Engineer Claudie Haignere. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

The Soyuz Taxi crew wave through a Soyuz hatch during their visit to the ISS

NASA Image and Video Library

2001-10-23

ISS003-E-7251 (23-31 October 2001) --- The Soyuz Taxi crewmembers wave from a Soyuz spacecraft docked to the International Space Station (ISS). Clockwise from the top are Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and French Flight Engineer Claudie Haignere. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera by one of the Expedition Three crew from the nadir docking port on the station.

Taxi and Expedition Three crews pose for a group photo in Zvezda during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-7037 (23-31 October 2001) --- Astronaut Frank L. Culbertson, Jr. (foreground), Expedition Three mission commander, and the Soyuz Taxi crewmembers assemble for a group photo in the Zvezda Service Module on the International Space Station (ISS). From the left are Flight Engineer Konstantin Kozeev, Commander Victor Afanasyev, and French Flight Engineer Claudie Haignere. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

The Soyuz Taxi crew adhere their logo to a wall in Node 1 during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-7056 (23-31 October 2001) --- The Soyuz Taxi crewmembers, Commander Victor Afanasyev (left), French Flight Engineer Claudie Haignere and Flight Engineer Konstantin Kozeev, add their crew patch to the growing collection, in the Unity node, of insignias representing crews who have worked on the International Space Station (ISS). Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

The Soyuz Taxi crew pose with the ISS ship log in Node 1 during Expedition Three

NASA Image and Video Library

2001-10-23

ISS003-E-7084 (23-31 October 2001) --- The Soyuz Taxi crewmembers, Flight Engineer Konstantin Kozeev (left), Commander Victor Afanasyev and French Flight Engineer Claudie Haignere add their names to the list of the International Space Station (ISS) visitors in the ship’s log in the Unity node. Afanasyev and Kozeev represent Rosaviakosmos, and Haignere represents ESA, carrying out a flight program for CNES, the French Space Agency, under a commercial contract with the Russian Aviation and Space Agency. This image was taken with a digital still camera.

PERFORMANCE AND DURABILITY OF THE PSA PEUGEOT CITROEN'S DPF SYSTEM ON A TAXI FLEET IN THE PARIS AREA

DOE Office of Scientific and Technical Information (OSTI.GOV)

COROLLER, P; PLASSAT, G

The use of Diesel engines has strongly increased during the last years and now represents 40% of the sales in Europe and up to 50% of the number of cars in circulation for some countries. This success is linked not only to the economical aspect of the use of such vehicles, but also to the recent technological improvements of these engines. The new technical solutions (high pressure direct injection, turbocharger) have indeed allowed the increase of these engine performances while decreasing their fuel consumption, pollutant emissions and noise level. From an environment point of view, Diesel engines are nevertheless penalizedmore » by their particulates and NOx emissions. The study and the treatment of the particulate, highly criticized for their potential impact on health, are the subject of numerous works of characterizations and developments. PSA Peugeot Citroen has recently (2000) launched its particulate filter technology on several types of vehicles (500,000 vehicles with DPF have been sold today). In order to evaluate the durability of this technology over a long period of time, a study program has been set-up by ADEME (French Environmental Agency), IFP Powertrain, PSA Peugeot Citroen and Taxis G7 (a Parisian taxis Company). The objective is to study the evolution of five taxis and their after-treatment system performances over 80,000km mileage--which corresponds to the recommended mileage before the first DPF maintenance--in hard urban driving conditions, as well over 120,000km, after the DPF maintenance and remanufacturing. More specifically, the following evaluations are being performed at regular intervals (around 20,000km): regulated gaseous pollutant emissions on NEDC cycle, particulate emissions and unregulated pollutant emissions. The results obtained until now have not shown any degradation of the particulate filter efficiency (more than 90%). This paper presents the methodology set-up, and the explanation of the first results obtained. Indeed, a

HIV related risk behaviours among taxi drivers and their assistants in Addis Ababa, Ethiopia: descriptive cross-sectional survey.

PubMed

Lakew, Yihunie; Tamene, Habtamu

2014-04-08

Risk taking behaviours in relation to HIV among the mobile population is a growing public health concern in many developing countries, including Ethiopia. The aim of this study was to describe risky sexual behaviours and associated factors among male taxi drivers and assistants in Addis Ababa. A descriptive cross-sectional survey design with multistage cluster sampling procedure was employed to select 615 individuals for interview. Seventy six percent of the respondents were sexually active. Nearly 31% of the respondents reported casual sex and 7% of them did not use a condom with their most recent casual sex partner. More than half (58.5%) of the respondents had no condom use efficacy. Condom breakage and/or slippage during sex had been encountered by 44% of respondents with casual partners and sex during menstruation had ever occurred among 17% of respondents. Eleven percent had experienced sex with female sex workers. Thirty-three percent of the respondents were unfaithful to their spouse/steady partners. Multivariate analysis revealed that living with parents [AOR 95% CI; 2(1.14-3.60)], non-khat chewers [AOR 95% CI; 3.7(2.13-6.31)], never taken VCT [AOR 95% CI; 3.5(1.84-6.72)], middle-class monthly cash gain [AOR 95% CI; 0.5(0.25-0.98)] and more years of experience working on a taxi [AOR 95% CI; 0.17(0.60-0.47)] were statistically significant to influence lifetime abstinence. Non-khat chewers [AOR 95% CI; 0.53(0.37-0.78)], never taken VCT [AOR 95% CI; 0.54(0.36-0.88)] and higher monthly cash gain [AOR 95% CI; 2.9(1.14-7.19)] had a statistically significant association with condom use efficacy. Living with parents [AOR 95% CI; 2(1.31-3.72)], living with friends [AOR 95% CI; 6.4(3.13-12.89)] and non-khat chewers [AOR 95% CI; 2(1.34-3.53)] were risk factors found to be associated with faithfulness. Risky sexual behaviours in this sub-population were considerable and associated factors were found to be multidimensional. Therefore, there is a need for robust

A coordinated sequence of distinct flagellar waveforms enables a sharp flagellar turn mediated by squid sperm pH-taxis.

PubMed

Iida, Tomohiro; Iwata, Yoko; Mohri, Tatsuma; Baba, Shoji A; Hirohashi, Noritaka

2017-10-11

Animal spermatozoa navigate by sensing ambient chemicals to reach the site of fertilization. Generally, such chemicals derive from the female reproductive organs or cells. Exceptionally, squid spermatozoa mutually release and perceive carbon dioxide to form clusters after ejaculation. We previously identified the pH-taxis by which each spermatozoon can execute a sharp turn, but how flagellar dynamics enable this movement remains unknown. Here, we show that initiation of the turn motion requires a swim down a steep proton gradient (a theoretical estimation of ≥0.025 pH/s), crossing a threshold pH value of ~5.5. Time-resolved kinematic analysis revealed that the turn sequence results from the rhythmic exercise of two flagellar motions: a stereotypical flagellar 'bent-cane' shape followed by asymmetric wave propagation, which enables a sharp turn in the realm of low Reynolds numbers. This turning episode is terminated by an 'overshoot' trajectory that differs from either straight-line motility or turning. As with bidirectional pH-taxes in some bacteria, squid spermatozoa also showed repulsion from strong acid conditions with similar flagellar kinematics as in positive pH-taxis. These findings indicate that squid spermatozoa might have a unique reorientation mechanism, which could be dissimilar to that of classical egg-guided sperm chemotaxis in other marine invertebrates.

Neural Correlates of Phrase Rhythm: An EEG Study of Bipartite vs. Rondo Sonata Form.

PubMed

Martínez-Rodrigo, Arturo; Fernández-Sotos, Alicia; Latorre, José Miguel; Moncho-Bogani, José; Fernández-Caballero, Antonio

2017-01-01

This paper introduces the neural correlates of phrase rhythm. In short, phrase rhythm is the rhythmic aspect of phrase construction and the relationships between phrases. For the sake of establishing the neural correlates, a musical experiment has been designed to induce music-evoked stimuli related to phrase rhythm. Brain activity is monitored through electroencephalography (EEG) by using a brain-computer interface. The power spectral value of each EEG channel is estimated to obtain how power variance distributes as a function of frequency. Our experiment shows statistical differences in theta and alpha bands in the phrase rhythm variations of two classical sonatas, one in bipartite form and the other in rondo form.

Impact of biased scores on ranking in bipartite competition networks and inference of modular structure via generalized modularity

NASA Astrophysics Data System (ADS)

Jeon, Gyuhyeon; Park, Juyong

2017-02-01

In the common jury-contestant competition format, a jury consisting of multiple judges grade contestants on their performances to determine their ranking. Unlike in another common competition format where two contestants play a head-to-head match to produce the winner such as in football or basketball, the objectivity of judges are often called into question, potentially undermining the public's trust in the fairness of the competition. In this work we show, by modeling the jury-contestant competition format as a weighted bipartite network, how one can identify biased scores and how they impact the competition and its structure. Analyzing the prestigious International Chopin Piano Competition of 2015 as an example with a well-publicized scoring controversy, we show that the presence of even a very small fraction of biased edges can gravely distort our inference of the network structure —in the example a single biased edge is shown to lead to an incorrect “solution” that also wrongly appears to be robust exclusively, dominating other reasonable solutions— highlighting the importance of bias detection and elimination in network inference. In the process our work also presents a modified modularity measure for the one-mode projection of weighted complete bipartite networks.

Learning and evolution in bacterial taxis: an operational amplifier circuit modeling the computational dynamics of the prokaryotic 'two component system' protein network.

PubMed

Di Paola, Vieri; Marijuán, Pedro C; Lahoz-Beltra, Rafael

2004-01-01

Adaptive behavior in unicellular organisms (i.e., bacteria) depends on highly organized networks of proteins governing purposefully the myriad of molecular processes occurring within the cellular system. For instance, bacteria are able to explore the environment within which they develop by utilizing the motility of their flagellar system as well as a sophisticated biochemical navigation system that samples the environmental conditions surrounding the cell, searching for nutrients or moving away from toxic substances or dangerous physical conditions. In this paper we discuss how proteins of the intervening signal transduction network could be modeled as artificial neurons, simulating the dynamical aspects of the bacterial taxis. The model is based on the assumption that, in some important aspects, proteins can be considered as processing elements or McCulloch-Pitts artificial neurons that transfer and process information from the bacterium's membrane surface to the flagellar motor. This simulation of bacterial taxis has been carried out on a hardware realization of a McCulloch-Pitts artificial neuron using an operational amplifier. Based on the behavior of the operational amplifier we produce a model of the interaction between CheY and FliM, elements of the prokaryotic two component system controlling chemotaxis, as well as a simulation of learning and evolution processes in bacterial taxis. On the one side, our simulation results indicate that, computationally, these protein 'switches' are similar to McCulloch-Pitts artificial neurons, suggesting a bridge between evolution and learning in dynamical systems at cellular and molecular levels and the evolutive hardware approach. On the other side, important protein 'tactilizing' properties are not tapped by the model, and this suggests further complexity steps to explore in the approach to biological molecular computing.

Injury severity analysis in taxi-pedestrian crashes: An application of reconstructed crash data using a vehicle black box.

PubMed

Chung, Younshik

2018-02-01

In-vehicle recording devices have enabled recent changes in methodological paradigms for traffic safety research. Such devices include event data recorders (EDRs), vehicle black boxes (VBBs), and various sensors used in naturalistic driving studies (NDSs). These technologies may help improve the validity of models used to assess impacts on traffic safety. The objective of this study is to analyze the injury severity in taxi-pedestrian crashes using the accurate crash data from VBBs, such as the time-to-collision (TTC), speed, angle, and region of the crash. VBB data from a two-year period (2010-2011) were collected from taxis operating in Incheon, South Korea. An ordered probit model was then applied to analyze the injury severity in crashes. Five variables were found to have a greater effect on injury severity: crash speed, crashes in no-median sections, crashes where the secondary impact object of pedestrians was the crash vehicle, crashes where the third impact object of pedestrians was another moving vehicle, and crashes where the third impact region of pedestrians was their head. However, injuries were less severe in crashes where the first impact region on the pedestrian was their leg, crashes with the car moving in a straight line, and crashes involving junior high school students. Copyright © 2017 Elsevier Ltd. All rights reserved.

The bipartite mitochondrial genome of Ruizia karukerae (Rhigonematomorpha, Nematoda).

PubMed

Kim, Taeho; Kern, Elizabeth; Park, Chungoo; Nadler, Steven A; Bae, Yeon Jae; Park, Joong-Ki

2018-05-10

Mitochondrial genes and whole mitochondrial genome sequences are widely used as molecular markers in studying population genetics and resolving both deep and shallow nodes in phylogenetics. In animals the mitochondrial genome is generally composed of a single chromosome, but mystifying exceptions sometimes occur. We determined the complete mitochondrial genome of the millipede-parasitic nematode Ruizia karukerae and found its mitochondrial genome consists of two circular chromosomes, which is highly unusual in bilateral animals. Chromosome I is 7,659 bp and includes six protein-coding genes, two rRNA genes and nine tRNA genes. Chromosome II comprises 7,647 bp, with seven protein-coding genes and 16 tRNA genes. Interestingly, both chromosomes share a 1,010 bp sequence containing duplicate copies of cox2 and three tRNA genes (trnD, trnG and trnH), and the nucleotide sequences between the duplicated homologous gene copies are nearly identical, suggesting a possible recent genesis for this bipartite mitochondrial genome. Given that little is known about the formation, maintenance or evolution of abnormal mitochondrial genome structures, R. karukerae mtDNA may provide an important early glimpse into this process.

I(CES)-cubes: a modular self-reconfigurable bipartite robotic system

NASA Astrophysics Data System (ADS)

Unsal, Cem; Kiliccote, Han; Khosla, Pradeep K.

1999-08-01

In this manuscript, we introduce I(CES)-Cubes, a class of 3D modular robotic system that is capable of reconfiguring itself in order to adapt to its environment. This is a bipartite system, i.e. a collection of (i) active elements capable of actuation, and (ii) passive elements acting as connectors between actuated elements. Active elements, called links, are 3-DOF manipulators that are capable of attaching/detaching themselves to/from the passive elements. The cubes can then be positioned and oriented using links, which are independent mechatronic elements. Self- reconfiguration property enables the system to performed locomotion tasks over difficult terrain. For example, the system would be capable of moving over obstacles and climbing stairs. These task are performed by positing and orienting cubes and links to form a 3D network with required shape and position. This paper describes the design of the passive and active elements, the attachment mechanics, and several reconfiguration scenarios. Specifics of the hardware implementation and result of experiments with current prototypes are also given.

Neural Correlates of Phrase Rhythm: An EEG Study of Bipartite vs. Rondo Sonata Form

PubMed Central

Martínez-Rodrigo, Arturo; Fernández-Sotos, Alicia; Latorre, José Miguel; Moncho-Bogani, José; Fernández-Caballero, Antonio

2017-01-01

This paper introduces the neural correlates of phrase rhythm. In short, phrase rhythm is the rhythmic aspect of phrase construction and the relationships between phrases. For the sake of establishing the neural correlates, a musical experiment has been designed to induce music-evoked stimuli related to phrase rhythm. Brain activity is monitored through electroencephalography (EEG) by using a brain–computer interface. The power spectral value of each EEG channel is estimated to obtain how power variance distributes as a function of frequency. Our experiment shows statistical differences in theta and alpha bands in the phrase rhythm variations of two classical sonatas, one in bipartite form and the other in rondo form. PMID:28496406

Cluster Analysis of Weighted Bipartite Networks: A New Copula-Based Approach

PubMed Central

Chessa, Alessandro; Crimaldi, Irene; Riccaboni, Massimo; Trapin, Luca

2014-01-01

In this work we are interested in identifying clusters of “positional equivalent” actors, i.e. actors who play a similar role in a system. In particular, we analyze weighted bipartite networks that describes the relationships between actors on one side and features or traits on the other, together with the intensity level to which actors show their features. We develop a methodological approach that takes into account the underlying multivariate dependence among groups of actors. The idea is that positions in a network could be defined on the basis of the similar intensity levels that the actors exhibit in expressing some features, instead of just considering relationships that actors hold with each others. Moreover, we propose a new clustering procedure that exploits the potentiality of copula functions, a mathematical instrument for the modelization of the stochastic dependence structure. Our clustering algorithm can be applied both to binary and real-valued matrices. We validate it with simulations and applications to real-world data. PMID:25303095

Bipartite Networks of Universities and Companies: Recruiting New Graduates in Japan

NASA Astrophysics Data System (ADS)

Takahashi, Katsuhide; Kobayashi, Yuh; Kondo, Yohei; Takayasu, Hideki; Takayasu, Misako

We investigated the bipartite Universities-Companies Network in Japan in terms of companies' recruitment of new graduates. In Japan, graduates of universities are typically hired by companies upon their graduation. To examine socially accepted ideas about this recruiting system, we combined different types of data on education, recruitment and corporate finance. The hypothesis that graduates from prestigious universities have the advantage of entering excellent companies was verified by examining the determinants of ratio of graduates entering top-ranked companies. Through hierarchical clustering, we obtained classification trees and observed the stability of their structure, as well as interesting changes corresponding to the business climate. We also calculated weighted HITS hub and authority values for each university and company and identified the links between the results of this analysis and those above. Finally, analysis of all the data indicated that excellent companies recruiting many graduates from prestigious universities do not necessarily show superb performance in profit-making and growth.

Modeling discrete combinatorial systems as alphabetic bipartite networks: theory and applications.

PubMed

Choudhury, Monojit; Ganguly, Niloy; Maiti, Abyayananda; Mukherjee, Animesh; Brusch, Lutz; Deutsch, Andreas; Peruani, Fernando

2010-03-01

Genes and human languages are discrete combinatorial systems (DCSs), in which the basic building blocks are finite sets of elementary units: nucleotides or codons in a DNA sequence, and letters or words in a language. Different combinations of these finite units give rise to potentially infinite numbers of genes or sentences. This type of DCSs can be represented as an alphabetic bipartite network (ABN) where there are two kinds of nodes, one type represents the elementary units while the other type represents their combinations. Here, we extend and generalize recent analytical findings for ABNs derived in [Peruani, Europhys. Lett. 79, 28001 (2007)] and empirically investigate two real world systems in terms of ABNs, the codon gene and the phoneme-language network. The one-mode projections onto the elementary basic units are also studied theoretically as well as in real world ABNs. We propose the use of ABNs as a means for inferring the mechanisms underlying the growth of real world DCSs.

Cascading Failures in Bi-partite Graphs: Model for Systemic Risk Propagation

PubMed Central

Huang, Xuqing; Vodenska, Irena; Havlin, Shlomo; Stanley, H. Eugene

2013-01-01

As economic entities become increasingly interconnected, a shock in a financial network can provoke significant cascading failures throughout the system. To study the systemic risk of financial systems, we create a bi-partite banking network model composed of banks and bank assets and propose a cascading failure model to describe the risk propagation process during crises. We empirically test the model with 2007 US commercial banks balance sheet data and compare the model prediction of the failed banks with the real failed banks after 2007. We find that our model efficiently identifies a significant portion of the actual failed banks reported by Federal Deposit Insurance Corporation. The results suggest that this model could be useful for systemic risk stress testing for financial systems. The model also identifies that commercial rather than residential real estate assets are major culprits for the failure of over 350 US commercial banks during 2008–2011. PMID:23386974

The Effects of Projected Future Demand Including Very Light Jet Air-Taxi Operations on U.S. National Airspace System Delays as a Function of Next Generation Air Transportation System Airspace Capacity

NASA Technical Reports Server (NTRS)

Smith, Jerry; Viken, Jeff; Dollyhigh, Samuel; Trani, Antonio; Baik, Hojong; Hinze, Nicholas; Ashiabor, Senanu

2007-01-01

This paper presents the results from a study which investigates the potential effects of the growth in air traffic demand including projected Very Light Jet (VLJ) air-taxi operations adding to delays experienced by commercial passenger air transportation in the year 2025. The geographic region studied is the contiguous United States (U.S.) of America, although international air traffic to and from the U.S. is included. The main focus of this paper is to determine how much air traffic growth, including VLJ air-taxi operations will add to enroute airspace congestion and determine what additional airspace capacity will be needed to accommodate the expected demand. Terminal airspace is not modeled and increased airport capacity is assumed.

Indications of a pan-hemispheric bi-partition of the Younger Dryas Stadial from Lake Suigetsu, Japan

NASA Astrophysics Data System (ADS)

Schlolaut, Gordon; Brauer, Achim; Nakagawa, Takeshi; Lamb, Henry; Marshall, Michael; Kato-Saito, Megumi; Staff, Richard; Bronk Ramsey, Christopher; Bryant, Charlotte

2016-04-01

The Younger Dryas Stadial marks the final succession of climatic fluctuations of the last Glacial. Whilst well studied in records from Europe and Greenland, few high resolution records are available from East Asia. Here we present a high resolution, multi-proxy study of the Lake Suigetsu (Japan) sediments using the 'SG06' composite profile. Utilising microfacies, μXRF, pollen and diatom analysis we characterise changes occurring in the timeframe corresponding to the Younger Dryas Stadial. Firstly, our results show that the climatic equivalent of the Younger Dryas at Lake Suigetsu shows no major lead or lag in comparison to records from the North Atlantic region, which was postulated by an earlier project on the Suigetsu sediments ('SG93'). Reason for this disagreement between the SG06 and SG93 core is that the SG93 core/chronology was compromised by gaps between individual cores and varve count uncertainties. Furthermore, some of the analysed proxies from the SG06 core show a sub-division of the Younger Dryas Stadial. The timing of this sub-division is similar to the bi-partition of the Younger Dryas Stadial observed in a number of European records (e.g. Lane et al., 2013). This bi-partition was related to a northward shift of the westerly wind jet in the North Atlantic region. Our findings imply that the underlying climatic mechanism operated on a hemispheric rather than just on a regional scale. References: Lane et al. 2013, Volcanic ash reveals time-transgressive abrupt climate change during the Younger Dryas, Geology 41, 1251-1254

Taxiing, Take-Off, and Landing Simulation of the High Speed Civil Transport Aircraft

NASA Technical Reports Server (NTRS)

Reaves, Mercedes C.; Horta, Lucas G.

1999-01-01

The aircraft industry jointly with NASA is studying enabling technologies for higher speed, longer range aircraft configurations. Higher speeds, higher temperatures, and aerodynamics are driving these newer aircraft configurations towards long, slender, flexible fuselages. Aircraft response during ground operations, although often overlooked, is a concern due to the increased fuselage flexibility. This paper discusses modeling and simulation of the High Speed Civil Transport aircraft during taxiing, take-off, and landing. Finite element models of the airframe for various configurations are used and combined with nonlinear landing gear models to provide a simulation tool to study responses to different ground input conditions. A commercial computer simulation program is used to numerically integrate the equations of motion and to compute estimates of the responses using an existing runway profile. Results show aircraft responses exceeding safe acceptable human response levels.

Shuttle Endeavour Mated to 747 SCA Taxi to Runway for Delivery to Kennedy Space Center, Florida

NASA Image and Video Library

1991-05-02

NASA's 747 Shuttle Carrier Aircraft No. 911, with the space shuttle orbiter Endeavour securely mounted atop its fuselage, taxies to the runway to begin the ferry flight from Rockwell's Plant 42 at Palmdale, California, where the orbiter was built, to the Kennedy Space Center, Florida. At Kennedy, the space vehicle was processed and launched on orbital mission STS-49, which landed at NASA's Ames-Dryden Flight Research Facility (later redesignated Dryden Flight Research Center), Edwards, California, 16 May 1992. NASA 911, the second modified 747 that went into service in November 1990, has special support struts atop the fuselage and internal strengthening to accommodate the added weight of the orbiters.

The Detection of Transport Land-Use Data Using Crowdsourcing Taxi Trajectory

NASA Astrophysics Data System (ADS)

Ai, T.; Yang, W.

2016-06-01

This study tries to explore the question of transport land-use change detection by large volume of vehicle trajectory data, presenting a method based on Deluanay triangulation. The whole method includes three steps. The first one is to pre-process the vehicle trajectory data including the point anomaly removing and the conversion of trajectory point to track line. Secondly, construct Deluanay triangulation within the vehicle trajectory line to detect neighborhood relation. Considering the case that some of the trajectory segments are too long, we use a interpolation measure to add more points for the improved triangulation. Thirdly, extract the transport road by cutting short triangle edge and organizing the polygon topology. We have conducted the experiment of transport land-use change discovery using the data of taxi track in Beijing City. We extract not only the transport land-use area but also the semantic information such as the transformation speed, the traffic jam distribution, the main vehicle movement direction and others. Compared with the existed transport network data, such as OpenStreet Map, our method is proved to be quick and accurate.

Topological collective plasmons in bipartite chains of metallic nanoparticles

NASA Astrophysics Data System (ADS)

Downing, Charles A.; Weick, Guillaume

2017-03-01

We study a bipartite linear chain constituted by spherical metallic nanoparticles, where each nanoparticle supports a localized surface plasmon. The near-field dipolar interaction between the localized surface plasmons gives rise to collective plasmons, which are extended over the whole nanoparticle array. We derive analytically the spectrum and the eigenstates of the collective plasmonic excitations. At the edge of the Brillouin zone, the spectrum is of a pseudorelativistic nature similar to that present in the electronic band structure of polyacetylene. We find the effective Dirac Hamiltonian for the collective plasmons and show that the corresponding spinor eigenstates represent one-dimensional Dirac-like massive bosonic excitations. Therefore, the plasmonic lattice exhibits similar effects to those found for electrons in one-dimensional Dirac materials, such as the ability for transmission with highly suppressed backscattering due to Klein tunneling. We also show that the system is governed by a nontrivial Zak phase, which predicts the manifestation of edge states in the chain. When two dimerized chains with different topological phases are connected, we find the appearance of the bosonic version of a Jackiw-Rebbi midgap state. We further investigate the radiative and nonradiative lifetimes of the collective plasmonic excitations and comment on the challenges for experimental realization of the topological effects found theoretically.

The N Terminus of the Retinoblastoma Protein Inhibits DNA Replication via a Bipartite Mechanism Disrupted in Partially Penetrant Retinoblastomas

PubMed Central

Borysov, Sergiy I.; Nepon-Sixt, Brook S.

2015-01-01

The N-terminal domain of the retinoblastoma (Rb) tumor suppressor protein (RbN) harbors in-frame exon deletions in partially penetrant hereditary retinoblastomas and is known to impair cell growth and tumorigenesis. However, how such RbN deletions contribute to Rb tumor- and growth-suppressive functions is unknown. Here we establish that RbN directly inhibits DNA replication initiation and elongation using a bipartite mechanism involving N-terminal exons lost in cancer. Specifically, Rb exon 7 is necessary and sufficient to target and inhibit the replicative CMG helicase, resulting in the accumulation of inactive CMGs on chromatin. An independent N-terminal loop domain, which forms a projection, specifically blocks DNA polymerase α (Pol-α) and Ctf4 recruitment without affecting DNA polymerases ε and δ or the CMG helicase. Individual disruption of exon 7 or the projection in RbN or Rb, as occurs in inherited cancers, partially impairs the ability of Rb/RbN to inhibit DNA replication and block G1-to-S cell cycle transit. However, their combined loss abolishes these functions of Rb. Thus, Rb growth-suppressive functions include its ability to block replicative complexes via bipartite, independent, and additive N-terminal domains. The partial loss of replication, CMG, or Pol-α control provides a potential molecular explanation for how N-terminal Rb loss-of-function deletions contribute to the etiology of partially penetrant retinoblastomas. PMID:26711265

Lévy-taxis: a novel search strategy for finding odor plumes in turbulent flow-dominated environments

NASA Astrophysics Data System (ADS)

Pasternak, Zohar; Bartumeus, Frederic; Grasso, Frank W.

2009-10-01

Locating chemical plumes in aquatic or terrestrial environments is important for many economic, conservation, security and health related human activities. The localization process is composed mainly of two phases: finding the chemical plume and then tracking it to its source. Plume tracking has been the subject of considerable study whereas plume finding has received little attention. We address here the latter issue, where the searching agent must find the plume in a region often many times larger than the plume and devoid of the relevant chemical cues. The probability of detecting the plume not only depends on the movements of the searching agent but also on the fluid mechanical regime, shaping plume intermittency in space and time; this is a basic, general problem when exploring for ephemeral resources (e.g. moving and/or concealing targets). Here we present a bio-inspired search strategy named Lévy-taxis that, under certain conditions, located odor plumes significantly faster and with a better success rate than other search strategies such as Lévy walks (LW), correlated random walks (CRW) and systematic zig-zag. These results are based on computer simulations which contain, for the first time ever, digitalized real-world water flow and chemical plume instead of their theoretical model approximations. Combining elements of LW and CRW, Lévy-taxis is particularly efficient for searching in flow-dominated environments: it adaptively controls the stochastic search pattern using environmental information (i.e. flow) that is available throughout the course of the search and shows correlation with the source providing the cues. This strategy finds natural application in real-world search missions, both by humans and autonomous robots, since it accomodates the stochastic nature of chemical mixing in turbulent flows. In addition, it may prove useful in the field of behavioral ecology, explaining and predicting the movement patterns of various animals searching for

Staufen1 is imported into the nucleolus via a bipartite nuclear localization signal and several modulatory determinants

PubMed Central

Martel, Catherine; Macchi, Paolo; Furic, Luc; Kiebler, Michael A.; Desgroseillers, Luc

2005-01-01

Mammalian Stau1 (Staufen1), a modular protein composed of several dsRBDs (double-stranded RNA-binding domains), is probably involved in mRNA localization. Although Stau1 is mostly described in association with the rough endoplasmic reticulum and ribosomes in the cytoplasm, recent studies suggest that it may transit through the nucleus/nucleolus. Using a sensitive yeast import assay, we show that Stau1 is actively imported into the nucleus through a newly identified bipartite nuclear localization signal. As in yeast, the bipartite nuclear localization signal is necessary for Stau1 nuclear import in mammalian cells. It is also required for Stau1 nucleolar trafficking. However, Stau1 nuclear transit seems to be regulated by mechanisms that involve cytoplasmic retention and/or facilitated nuclear export. Cytoplasmic retention is mainly achieved through the action of dsRBD3, with dsRBD2 playing a supporting role in this function. Similarly, dsRBD3, but not its RNA-binding activity, is critical for Stau1 nucleolar trafficking. The function of dsRBD3 is strengthened or stabilized by the presence of dsRBD4 but prevented by the interdomain between dsRBD2 and dsRBD3. Altogether, these results suggest that Stau1 nuclear trafficking is a highly regulated process involving several determinants. The presence of Stau1 in the nucleus/nucleolus suggests that it may be involved in ribonucleoprotein formation in the nucleus and/or in other nuclear functions not necessarily related to mRNA transport. PMID:16162096

Orbital Transfer Vehicle (space taxi) with aerobraking at Earth and Mars

NASA Technical Reports Server (NTRS)

1987-01-01

This report shall cover all major aspects of the design of an Aeroassisted Manned Transfer Vehicle (or TAXI) for use as part of advanced manned Mars missions based on a cycling ship concept. Along with the heliocentric orbiting Cycling Spacecraft, such a TAXI would be a primary component of a long-term transportation system for Mars exploration. The Aeroassisted Manned Transfer Vehicle (AMTV) design developed shall operate along transfer trajectories between Earth and a Cycling Spacecraft (designed by the University of Michigan) and Mars. All operations of the AMTV shall be done primarily within the sphere of influence of the two planets. Maximum delta-V's for the vehicle have been established near 9 km/sec, with transfer durations of about 3 days. Acceleration deltaV's will be accomplished using 3 SSME-based hydrogen-oxygen chemical rockets (l(sub sp) = 485 sec & Thrust greater than = 300,00 Ib(sub f)/engine) with a thrust vector directly opposite the aerobraking deceleration vector. The aerobraking deceleration portion of an AMTV mission would be accomplished in this design by a moderate L/D aeroshield of an ellipsoidally-blunt, raked-off, elliptic cone (EBROEC) shape. The reusable thermal protection material comprising the shield will consist of a flexible, multi-layer, ceramic fabric stretched over a lightweight, rigid, shape - defining truss structure. Behind this truss, other components, including the engine supports, would be attached and protected from heating during aerobraking passes. Among these other components would be 2 LOX tanks and 4 LH2 tanks (and their support frames) holding over 670,000 lbm of propellant necessary to impart the required delta-V to the 98,000 lbm burnout mass vehicle. A 20,000 lbm crew module with docking port (oriented parallel to the accel./decel. axis) will provide accommodations for 9 crew members (11 under extreme conditions) for durations up to seven days, thus allowing extra time for emergency situations. This AMTV will be

Editorial Commentary: Got Evidence? What We Really Need Is an Algorithm for Treating Symptomatic Bipartite Patella.

PubMed

Fithian, Donald C

2018-05-01

Bipartite patella is an uncommon but potentially troublesome problem for young athletes. Numerous uncontrolled retrospective studies have reported good results after various treatments. What is needed are studies that will guide workup and support treatment decisions based on the condition of the cartilage surfaces of the fragment, presence of pseudoarthrosis, and size and location of the fragment. To support decisions, we need prospective comparative studies, either randomized or, at least, prospective cohort studies that identify patients at the time of presentation, document key decision points, and follow patients to successful resolution of symptoms. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Collective Human Mobility Pattern from Taxi Trips in Urban Area

PubMed Central

Peng, Chengbin; Jin, Xiaogang; Wong, Ka-Chun; Shi, Meixia; Liò, Pietro

2012-01-01

We analyze the passengers' traffic pattern for 1.58 million taxi trips of Shanghai, China. By employing the non-negative matrix factorization and optimization methods, we find that, people travel on workdays mainly for three purposes: commuting between home and workplace, traveling from workplace to workplace, and others such as leisure activities. Therefore, traffic flow in one area or between any pair of locations can be approximated by a linear combination of three basis flows, corresponding to the three purposes respectively. We name the coefficients in the linear combination as traffic powers, each of which indicates the strength of each basis flow. The traffic powers on different days are typically different even for the same location, due to the uncertainty of the human motion. Therefore, we provide a probability distribution function for the relative deviation of the traffic power. This distribution function is in terms of a series of functions for normalized binomial distributions. It can be well explained by statistical theories and is verified by empirical data. These findings are applicable in predicting the road traffic, tracing the traffic pattern and diagnosing the traffic related abnormal events. These results can also be used to infer land uses of urban area quite parsimoniously. PMID:22529917

Dynamics of bloggers’ communities: Bipartite networks from empirical data and agent-based modeling

NASA Astrophysics Data System (ADS)

Mitrović, Marija; Tadić, Bosiljka

2012-11-01

We present an analysis of the empirical data and the agent-based modeling of the emotional behavior of users on the Web portals where the user interaction is mediated by posted comments, like Blogs and Diggs. We consider the dataset of discussion-driven popular Diggs, in which all comments are screened by machine-learning emotion detection in the text, to determine positive and negative valence (attractiveness and aversiveness) of each comment. By mapping the data onto a suitable bipartite network, we perform an analysis of the network topology and the related time-series of the emotional comments. The agent-based model is then introduced to simulate the dynamics and to capture the emergence of the emotional behaviors and communities. The agents are linked to posts on a bipartite network, whose structure evolves through their actions on the posts. The emotional states (arousal and valence) of each agent fluctuate in time, subject to the current contents of the posts to which the agent is exposed. By an agent’s action on a post its current emotions are transferred to the post. The model rules and the key parameters are inferred from the considered empirical data to ensure their realistic values and mutual consistency. The model assumes that the emotional arousal over posts drives the agent’s action. The simulations are preformed for the case of constant flux of agents and the results are analyzed in full analogy with the empirical data. The main conclusions are that the emotion-driven dynamics leads to long-range temporal correlations and emergent networks with community structure, that are comparable with the ones in the empirical system of popular posts. In view of pure emotion-driven agents actions, this type of comparisons provide a quantitative measure for the role of emotions in the dynamics on real blogs. Furthermore, the model reveals the underlying mechanisms which relate the post popularity with the emotion dynamics and the prevalence of negative

Interlocking directorates in Irish companies using a latent space model for bipartite networks

PubMed Central

Friel, Nial; Rastelli, Riccardo; Wyse, Jason; Raftery, Adrian E.

2016-01-01

We analyze the temporal bipartite network of the leading Irish companies and their directors from 2003 to 2013, encompassing the end of the Celtic Tiger boom and the ensuing financial crisis in 2008. We focus on the evolution of company interlocks, whereby a company director simultaneously sits on two or more boards. We develop a statistical model for this dataset by embedding the positions of companies and directors in a latent space. The temporal evolution of the network is modeled through three levels of Markovian dependence: one on the model parameters, one on the companies’ latent positions, and one on the edges themselves. The model is estimated using Bayesian inference. Our analysis reveals that the level of interlocking, as measured by a contraction of the latent space, increased before and during the crisis, reaching a peak in 2009, and has generally stabilized since then. PMID:27247395

Interlocking directorates in Irish companies using a latent space model for bipartite networks.

PubMed

Friel, Nial; Rastelli, Riccardo; Wyse, Jason; Raftery, Adrian E

2016-06-14

We analyze the temporal bipartite network of the leading Irish companies and their directors from 2003 to 2013, encompassing the end of the Celtic Tiger boom and the ensuing financial crisis in 2008. We focus on the evolution of company interlocks, whereby a company director simultaneously sits on two or more boards. We develop a statistical model for this dataset by embedding the positions of companies and directors in a latent space. The temporal evolution of the network is modeled through three levels of Markovian dependence: one on the model parameters, one on the companies' latent positions, and one on the edges themselves. The model is estimated using Bayesian inference. Our analysis reveals that the level of interlocking, as measured by a contraction of the latent space, increased before and during the crisis, reaching a peak in 2009, and has generally stabilized since then.

Response to defects in multipartite and bipartite entanglement of isotropic quantum spin networks

NASA Astrophysics Data System (ADS)

Roy, Sudipto Singha; Dhar, Himadri Shekhar; Rakshit, Debraj; SenDe, Aditi; Sen, Ujjwal

2018-05-01

Quantum networks are an integral component in performing efficient computation and communication tasks that are not accessible using classical systems. A key aspect in designing an effective and scalable quantum network is generating entanglement between its nodes, which is robust against defects in the network. We consider an isotropic quantum network of spin-1/2 particles with a finite fraction of defects, where the corresponding wave function of the network is rotationally invariant under the action of local unitaries. By using quantum information-theoretic concepts like strong subadditivity of von Neumann entropy and approximate quantum telecloning, we prove analytically that in the presence of defects, caused by loss of a finite fraction of spins, the network, composed of a fixed numbers of lattice sites, sustains genuine multisite entanglement and at the same time may exhibit finite moderate-range bipartite entanglement, in contrast to the network with no defects.

Chiral zero energy modes in two-dimensional disordered Dirac semimetals

NASA Astrophysics Data System (ADS)

Liu, Lei; Yu, Yan; Wu, Hai-Bin; Zhang, Yan-Yang; Liu, Jian-Jun; Li, Shu-Shen

2018-04-01

The vacancy-induced chiral zero energy modes (CZEMs) of chiral-unitary-class (AIII) and chiral-symplectic-class (CII) two-dimensional (2 D ) disordered Dirac semimetals realized on a square bipartite lattice are investigated numerically by using the Kubo-Greenwood formula with the kernel polynomial method. The results show that, for both systems, the CZEMs exhibit the critical delocalization. The CZEM conductivity remains a robust constant (i.e., σ CZEM≈1.05 e2/h ), which is insensitive to the sample sizes, the vacancy concentrations, and the numbers of moments of Chebyshev polynomials, i.e., the dephasing strength. For both kinds of chiral systems, the CZEM conductivities are almost identical. However, they are not equal to that of graphene (i.e., 4 e2/π h ), which belongs to the chiral orthogonal class (BDI) semimetal on a 2 D hexagonal bipartite lattice. In addition, for the case that the vacancy concentrations are different in the two sublattices, the CZEM conductivity vanishes, and thus both systems exhibit localization at the Dirac point. Moreover, a band gap and a mobility gap open around zero energy. The widths of the energy gaps and mobility gaps are increasing with larger vacancy concentration difference. The width of the mobility gap is greater than that of the band gap, and a δ -function-like peak of density of states emerges at the Dirac point within the band gap, implying the existence of numerous localized states.

Bipartite charge fluctuations in one-dimensional Z2 superconductors and insulators

NASA Astrophysics Data System (ADS)

Herviou, Loïc; Mora, Christophe; Le Hur, Karyn

2017-09-01

Bipartite charge fluctuations (BCFs) have been introduced to provide an experimental indication of many-body entanglement. They have proved themselves to be a very efficient and useful tool to characterize quantum phase transitions in a variety of quantum models conserving the total number of particles (or magnetization for spin systems) and can be measured experimentally. We study the BCFs in generic one-dimensional Z2 (topological) models including the Kitaev superconducting wire model, the Ising chain, or various topological insulators such as the Su-Schrieffer-Heeger model. The considered charge (either the fermionic number or the relative density) is no longer conserved, leading to macroscopic fluctuations of the number of particles. We demonstrate that at phase transitions characterized by a linear dispersion, the BCFs probe the change in a winding number that allows one to pinpoint the transition and corresponds to the topological invariant for standard models. Additionally, we prove that a subdominant logarithmic contribution is still present at the exact critical point. Its quantized coefficient is universal and characterizes the critical model. Results are extended to the Rashba topological nanowires and to the X Y Z model.

Assessment of Urban Aerial Taxi with Cryogenic Components Under Design Environment for Novel Vertical Lift Vehicles (DELIVER)

NASA Technical Reports Server (NTRS)

Snyder, Christopher

2017-01-01

Assessing the potential to bring 100 years of aeronautics knowledge to the entrepreneurs desktop to enable a design environment for emerging vertical lift vehicles is one goal for the NASA's Design Environment for Novel Vertical Lift Vehicles (DELIVER). As part of this effort, a system study was performed using a notional, urban aerial taxi system to better understand vehicle requirements along with the tools and methods capability to assess these vehicles and their subsystems using cryogenic cooled components. The baseline was a vertical take-off and landing (VTOL) aircraft, with all-electric propulsion system assuming 15 year technology performance levels and its capability limited to a pilot with one or two people and cargo. Hydrocarbon-fueled hybrid concepts were developed to improve mission capabilities. The hybrid systems resulted in significant improvements in maximum range and number of on demand mobility (ODM) missions that could be completed before refuel or recharge. An important consideration was thermal management, including the choice for air-cooled or cryogenic cooling using liquid natural gas (LNG) fuel. Cryogenic cooling for critical components can have important implications on component performance and size. Thermal loads were also estimated, subsequent effort will be required to verify feasibility for cooling airflow and packaging. LNG cryogenic cooling of selected components further improved vehicle range and reduced thermal loads, but the same concerns for airflow and packaging still need to be addressed. The use of the NASA Design and Analysis of Rotorcraft (NDARC) tool for vehicle sizing and mission analysis appears to be capable of supporting analyses for present and future types of vehicles, missions, propulsion, and energy sources. Further efforts are required to develop verified models for these new types of propulsion and energy sources in the size and use envisioned for these emerging vehicle and mission classes.

Assessment of Urban Aerial Taxi with Cryogenic Components under Design Environment for Novel Vertical Lift Vehicles (DELIVER)

NASA Technical Reports Server (NTRS)

Snyder, Christopher A.

2017-01-01

Assessing the potential to bring 100 years of aeronautics knowledge to the entrepreneurs desktop to enable a design environment for emerging vertical lift vehicles is one goal for the NASAs Design Environment for Novel Vertical Lift Vehicles (DELIVER). As part of this effort, a system study was performed using a notional, urban aerial taxi system to better understand vehicle requirements along with the tools and methods capability to assess these vehicles and their subsystems using cryogenic cooled components. The baseline was a vertical take-off and landing (VTOL) aircraft, with all-electric propulsion system assuming 15 year technology performance levels and its capability limited to a pilot with one or two people and cargo. Hydrocarbon-fueled hybrid concepts were developed to improve mission capabilities. The hybrid systems resulted in significant improvements in maximum range and number of on demand mobility (ODM) missions that could be completed before refuel or recharge. An important consideration was thermal management, including the choice for air-cooled or cryogenic cooling using liquid natural gas (LNG) fuel. Cryogenic cooling for critical components can have important implications on component performance and size. Thermal loads were also estimated, subsequent effort will be required to verify feasibility for cooling airflow and packaging. LNG cryogenic cooling of selected components further improved vehicle range and reduced thermal loads, but the same concerns for airflow and packaging still need to be addressed. The use of the NASA Design and Analysis of Rotorcraft (NDARC) tool for vehicle sizing and mission analysis appears to be capable of supporting analyses for present and future types of vehicles, missions, propulsion, and energy sources. Further efforts are required to develop verified models for these new types of propulsion and energy sources in the size and use envisioned for these emerging vehicle and mission classes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feibel, C.E.

This study uses multiple data collection and research methods including in depth interviews, 271 surveys of shared taxi and minibus operators, participant observation, secondary sources, and the literature on public transport from low, medium, and high-income countries. Extensive use is also made of a survey administered in Istanbul in 1976 to 1935 paratransit operators. Primary findings are that private buses are more efficient than public buses on a cost per passenger-km basis, and that private minibuses are as efficient as public buses. In terms of energy efficiency, minibuses are almost as efficient as public and private buses using actual-occupancy levels.more » Large shared taxis are twice as cost and energy efficient as cars, and small shared taxis 50% more efficient. In terms of investment cost per seat, large shared taxis have the lowest cost followed by smaller shared taxis, minibuses, and buses. Considering actual occupancy levels, minibuses are only slightly less effective in terms of congestion than buses, and large and small shared taxis are twice as effective as cars. It is also shown that minibuses and shared taxis have better service quality than buses because of higher frequencies and speeds, and because they provide a much higher probability of getting a seat than buses. Analysis of regulation and policy suggests that there are many unintended cost of public-transport regulations.« less

The family Rhabdoviridae: Mono- and bipartite negative-sense RNA viruses with diverse genome organization and common evolutionary origins

USGS Publications Warehouse

Dietzgen, Ralf G.; Kondo, Hideki; Goodin, Michael M.; Kurath, Gael; Vasilakis, Nikos

2017-01-01

The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the characteristics and diversity of rhabdoviruses, their taxonomic classification, replication mechanism, properties of classical rhabdoviruses such as rabies virus and rhabdoviruses with complex genomes, rhabdoviruses infecting aquatic species, and plant rhabdoviruses with both mono- and bipartite genomes.

Reactivation of latent herpes viruses in cosmonauts during a soyuz taxi mission

NASA Astrophysics Data System (ADS)

Mehta, Satish K.; Pierson, Duane L.

2007-09-01

The hypothesis tested by this project is that space flight increases the incidence and duration of herpes virus reactivation and shedding in saliva. Saliva, urine, and blood samples were collected from 3 crew members who participated in a 14-day Odessa Soyuz taxi mission. Saliva samples were collected before, during, and after the mission, and blood and urine were collected before and after the mission. The saliva and urine samples were analyzed using the polymerase chain reaction to detect the presence of 3 important herpes viruses. Epstein-Barr virus (EBV) and varicella-zoster virus (VZV) were tested in saliva, and cytomegalovirus (CMV) was measured in urine samples. Plasma antibodies levels to these viruses were determined by enzyme-linked immunosorbent assay before and after flight. EBV reactivated before, during, and after flight; CMV reactivated before and after flight; and VZV reactivated during and after flight. In other studies, greater frequencies of positive samples and greater numbers of copies of viral DNA have been found. No increases in titer of antibodies to these viruses were found, suggesting that an immune response may not be necessary for reactivation.

Survey of health and licensing policies for taxi drivers in Singapore, Hong Kong and Australia: a perspective from evidence on older drivers.

PubMed

Chan, M L; Gustafsson, L; Liddle, J

2010-12-01

With an ageing population, policy makers need to balance active ageing needs with older driver safety. In 2009, a survey of licensing policies for taxi drivers in Singapore, Hong Kong and Australia was undertaken for an evidence-based review of policies. Licensing requirements collected using semi-structured questionnaires were compared descriptively and with evidence from licensing policies on older drivers. All the regions used medical certifications with vision screening. The frequency of medical certification varied according to the renewal cycle and age. Medical guidelines on fitness to drive were available in Australia and Singapore. Legislation for self-reporting of medical conditions by drivers existed in Australia and Hong Kong. Legislation for reporting at-risk drivers by doctors was limited to two Australian states. There were differences in the minimum age and driving experience criteria, the use of practical training, written and English tests, age-based screening, mandatory retirement age, refresher courses, off- and on-road tests. Medical screening for at-risk drivers remains crucial. Age-based mandatory retirement policy at 73 years in Singapore is contrary to evidence-based practice. The lack of legislation for self-reporting of illness by drivers, the high minimum age criteria and therapy driving assessments for healthy taxi drivers are also unique to Singapore. There was stricter age-based relicensing from the age of 65 years in some Australian states and in Singapore. Continuing education for doctors, multi-tier screening for at-risk drivers and licensing policy changes are indicated.

A distributed-memory approximation algorithm for maximum weight perfect bipartite matching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azad, Ariful; Buluc, Aydin; Li, Xiaoye S.

We design and implement an efficient parallel approximation algorithm for the problem of maximum weight perfect matching in bipartite graphs, i.e. the problem of finding a set of non-adjacent edges that covers all vertices and has maximum weight. This problem differs from the maximum weight matching problem, for which scalable approximation algorithms are known. It is primarily motivated by finding good pivots in scalable sparse direct solvers before factorization where sequential implementations of maximum weight perfect matching algorithms, such as those available in MC64, are widely used due to the lack of scalable alternatives. To overcome this limitation, we proposemore » a fully parallel distributed memory algorithm that first generates a perfect matching and then searches for weightaugmenting cycles of length four in parallel and iteratively augments the matching with a vertex disjoint set of such cycles. For most practical problems the weights of the perfect matchings generated by our algorithm are very close to the optimum. An efficient implementation of the algorithm scales up to 256 nodes (17,408 cores) on a Cray XC40 supercomputer and can solve instances that are too large to be handled by a single node using the sequential algorithm.« less

The family Rhabdoviridae: mono- and bipartite negative-sense RNA viruses with diverse genome organization and common evolutionary origins.

PubMed

Dietzgen, Ralf G; Kondo, Hideki; Goodin, Michael M; Kurath, Gael; Vasilakis, Nikos

2017-01-02

The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the characteristics and diversity of rhabdoviruses, their taxonomic classification, replication mechanism, properties of classical rhabdoviruses such as rabies virus and rhabdoviruses with complex genomes, rhabdoviruses infecting aquatic species, and plant rhabdoviruses with both mono- and bipartite genomes. Copyright © 2016 Elsevier B.V. All rights reserved.

Perseus Taxi

NASA Technical Reports Server (NTRS)

1991-01-01

The Perseus proof-of-concept vehicle is seen here as it taxis on Rogers Dry Lake, adjacent the Dryden Flight Research Center, Edwards, California. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA) program, which later evolved into the ERAST project. The

Analytic renormalized bipartite and tripartite quantum discords with quantum phase transition in XXZ spins chain

NASA Astrophysics Data System (ADS)

Joya, Wajid; Khan, Salman; Khalid Khan, M.; Alam, Sher

2017-05-01

The behavior of bipartite quantum discord (BQD) and tripartite quantum discord (TQD) in the Heisenberg XXZ spins chain is investigated with the increasing size of the system using the approach of the quantum renormalization group method. Analytical relations for both BQD and TQD are obtained and the results are checked through numerical optimization. In the thermodynamics limit, both types of discord exhibit quantum phase transition (QPT). The boundary of QPT links the phases of saturated discord and zero discord. The first derivative of both discords becomes discontinuous at the critical point, which corresponds to the second-order phase transition. Qualitatively identical, the amount of saturated BQD strongly depends on the relative positions of spins inside a block. TQD can be a better candidate than BQD both for analyzing QPT and implementing quantum information tasks. The scaling behavior in the vicinity of the critical point is discussed.

TaxI: a software tool for DNA barcoding using distance methods

PubMed Central

Steinke, Dirk; Vences, Miguel; Salzburger, Walter; Meyer, Axel

2005-01-01

DNA barcoding is a promising approach to the diagnosis of biological diversity in which DNA sequences serve as the primary key for information retrieval. Most existing software for evolutionary analysis of DNA sequences was designed for phylogenetic analyses and, hence, those algorithms do not offer appropriate solutions for the rapid, but precise analyses needed for DNA barcoding, and are also unable to process the often large comparative datasets. We developed a flexible software tool for DNA taxonomy, named TaxI. This program calculates sequence divergences between a query sequence (taxon to be barcoded) and each sequence of a dataset of reference sequences defined by the user. Because the analysis is based on separate pairwise alignments this software is also able to work with sequences characterized by multiple insertions and deletions that are difficult to align in large sequence sets (i.e. thousands of sequences) by multiple alignment algorithms because of computational restrictions. Here, we demonstrate the utility of this approach with two datasets of fish larvae and juveniles from Lake Constance and juvenile land snails under different models of sequence evolution. Sets of ribosomal 16S rRNA sequences, characterized by multiple indels, performed as good as or better than cox1 sequence sets in assigning sequences to species, demonstrating the suitability of rRNA genes for DNA barcoding. PMID:16214755

Centurion Quarter-scale Prototype Pre-flight Taxi Test

NASA Technical Reports Server (NTRS)

1997-01-01

As crewmen jog and cycle alongside, a battery-powered, quarter-scale prototype of the remotely-piloted Centurion flying wing rolls across the El Mirage Dry Lake during pre-flight taxi tests. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar

NASA's space shuttle Atlantis and its 747 carrier taxied on the Edwards Air Force Base flightline as the unusual combination left for Kennedy Space Center, Florida, on March 1, 2001

NASA Image and Video Library

2001-03-01

NASA's space shuttle Atlantis and its 747 carrier taxied on the Edwards Air Force Base flightline as the unusual combination left for Kennedy Space Center, Florida, on March 1, 2001. Atlantis and the shuttle Columbia were both airborne on the same day as they migrated from California to Florida. Columbia underwent refurbishing at nearby Palmdale, California.

Detecting phase boundaries of quantum spin-1/2 XXZ ladder via bipartite and multipartite entanglement transitions

NASA Astrophysics Data System (ADS)

Singha Roy, Sudipto; Dhar, Himadri Shekhar; Rakshit, Debraj; Sen(De), Aditi; Sen, Ujjwal

2017-12-01

Phase transition in quantum many-body systems inevitably causes changes in certain physical properties which then serve as potential indicators of critical phenomena. Besides the traditional order parameters, characterization of quantum entanglement has proven to be a computationally efficient and successful method for detection of phase boundaries, especially in one-dimensional models. Here we determine the rich phase diagram of the ground states of a quantum spin-1/2 XXZ ladder by analyzing the variation of bipartite and multipartite entanglements. Our study characterizes the different ground state phases and notes the correspondence with known results, while highlighting the finer details that emerge from the behavior of ground state entanglement. Analysis of entanglement in the ground state provides a clearer picture of the complex ground state phase diagram of the system using only a moderate-size model.

Influence of intrinsic decoherence on tripartite entanglement and bipartite fidelity of polar molecules in pendular states.

PubMed

Han, Jia-Xing; Hu, Yuan; Jin, Yu; Zhang, Guo-Feng

2016-04-07

An array of ultracold polar molecules trapped in an external electric field is regarded as a promising carrier of quantum information. Under the action of this field, molecules are compelled to undergo pendular oscillations by the Stark effect. Particular attention has been paid to the influence of intrinsic decoherence on the model of linear polar molecular pendular states, thereby we evaluate the tripartite entanglement with negativity, as well as fidelity of bipartite quantum systems for input and output signals using electric dipole moments of polar molecules as qubits. According to this study, we consider three typical initial states for both systems, respectively, and investigate the temporal evolution with variable values of the external field intensity, the intrinsic decoherence factor, and the dipole-dipole interaction. Thus, we demonstrate the sound selection of these three main parameters to obtain the best entanglement degree and fidelity.

Effect of two-qutrit entanglement on quantum speed limit time of a bipartite V-type open system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behzadi, N., E-mail: n.behzadi@tabrizu.ac.ir; Ahansaz, B.; Ektesabi, A.

In the present paper, quantum speed limit (QSL) time of a bipartite V-type three-level atomic system under the effect of two-qutrit entanglement is investigated. Each party interacts with own independent reservoir. By considering two local unitarily equivalent Werner states and the Horodecki PPT state, as initial states, the QSL time is evaluated for each of them in the respective entangled regions. It is counterintuitively observed that the effect of entanglement on the QSL time driven from each of the initial Werner states are completely different when the degree of non-Markovianity is considerable. In addition, it is interesting that the effectmore » of entanglement of the non-equivalent Horodecki state on the calculated QSL time displays an intermediate behavior relative to the cases obtained for the Werner states.« less

From Ecology to Finance (and Back?): A Review on Entropy-Based Null Models for the Analysis of Bipartite Networks

NASA Astrophysics Data System (ADS)

Straka, Mika J.; Caldarelli, Guido; Squartini, Tiziano; Saracco, Fabio

2018-04-01

Bipartite networks provide an insightful representation of many systems, ranging from mutualistic networks of species interactions to investment networks in finance. The analyses of their topological structures have revealed the ubiquitous presence of properties which seem to characterize many—apparently different—systems. Nestedness, for example, has been observed in biological plant-pollinator as well as in country-product exportation networks. Due to the interdisciplinary character of complex networks, tools developed in one field, for example ecology, can greatly enrich other areas of research, such as economy and finance, and vice versa. With this in mind, we briefly review several entropy-based bipartite null models that have been recently proposed and discuss their application to real-world systems. The focus on these models is motivated by the fact that they show three very desirable features: analytical character, general applicability, and versatility. In this respect, entropy-based methods have been proven to perform satisfactorily both in providing benchmarks for testing evidence-based null hypotheses and in reconstructing unknown network configurations from partial information. Furthermore, entropy-based models have been successfully employed to analyze ecological as well as economic systems. As an example, the application of entropy-based null models has detected early-warning signals, both in economic and financial systems, of the 2007-2008 world crisis. Moreover, they have revealed a statistically-significant export specialization phenomenon of country export baskets in international trade, a result that seems to reconcile Ricardo's hypothesis in classical economics with recent findings on the (empirical) diversification industrial production at the national level. Finally, these null models have shown that the information contained in the nestedness is already accounted for by the degree sequence of the corresponding graphs.

Structural insights into the stabilization of MALAT1 noncoding RNA by a bipartite triple helix

PubMed Central

Brown, Jessica A.; Bulkley, David; Wang, Jimin; Valenstein, Max L.; Yario, Therese A.; Steitz, Thomas A.; Steitz, Joan A.

2014-01-01

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a highly-abundant nuclear long noncoding RNA that promotes malignancy. A 3′-stem-loop structure is predicted to confer stability by engaging a downstream A-rich tract in a triple helix, similar to the expression and nuclear retention element (ENE) from the KSHV polyadenylated nuclear RNA. The 3.1-Å resolution crystal structure of the human MALAT1 ENE and A-rich tract reveals a bipartite triple helix containing stacks of five and four U•A-U triples separated by a C+•G-C triplet and C-G doublet, extended by two A-minor interactions. In vivo decay assays indicate that this blunt-ended triple helix, with the 3′ nucleotide in a U•A-U triple, inhibits rapid nuclear RNA decay. Interruption of the triple helix by the C-G doublet induces a “helical reset” that explains why triple-helical stacks longer than six do not occur in nature. PMID:24952594

Quantum teleportation via noisy bipartite and tripartite accelerating quantum states: beyond the single mode approximation

NASA Astrophysics Data System (ADS)

Zounia, M.; Shamirzaie, M.; Ashouri, A.

2017-09-01

In this paper quantum teleportation of an unknown quantum state via noisy maximally bipartite (Bell) and maximally tripartite (Greenberger-Horne-Zeilinger (GHZ)) entangled states are investigated. We suppose that one of the observers who would receive the sent state accelerates uniformly with respect to the sender. The interactions of the quantum system with its environment during the teleportation process impose noises. These (unital and nonunital) noises are: phase damping, phase flip, amplitude damping and bit flip. In expressing the modes of the Dirac field used as qubits, in the accelerating frame, the so-called single mode approximation is not imposed. We calculate the fidelities of teleportation, and discuss their behaviors using suitable plots. The effects of noise, acceleration and going beyond the single mode approximation are discussed. Although the Bell states bring higher fidelities than GHZ states, the global behaviors of the two quantum systems with respect to some noise types, and therefore their fidelities, are different.

Reaction factoring and bipartite update graphs accelerate the Gillespie Algorithm for large-scale biochemical systems.

PubMed

Indurkhya, Sagar; Beal, Jacob

2010-01-06

ODE simulations of chemical systems perform poorly when some of the species have extremely low concentrations. Stochastic simulation methods, which can handle this case, have been impractical for large systems due to computational complexity. We observe, however, that when modeling complex biological systems: (1) a small number of reactions tend to occur a disproportionately large percentage of the time, and (2) a small number of species tend to participate in a disproportionately large percentage of reactions. We exploit these properties in LOLCAT Method, a new implementation of the Gillespie Algorithm. First, factoring reaction propensities allows many propensities dependent on a single species to be updated in a single operation. Second, representing dependencies between reactions with a bipartite graph of reactions and species requires only storage for reactions, rather than the required for a graph that includes only reactions. Together, these improvements allow our implementation of LOLCAT Method to execute orders of magnitude faster than currently existing Gillespie Algorithm variants when simulating several yeast MAPK cascade models.

Random hopping fermions on bipartite lattices: density of states, inverse participation ratios, and their correlations in a strong disorder regime

NASA Astrophysics Data System (ADS)

Yamada, Hiroki; Fukui, Takahiro

2004-02-01

We study Anderson localization of non-interacting random hopping fermions on bipartite lattices in two dimensions, focusing our attention to strong disorder features of the model. We concentrate ourselves on specific models with a linear dispersion in the vicinity of the band center, which can be described by a Dirac fermion in the continuum limit. Based on the recent renormalization group method developed by Carpentier and Le Doussal for the XY gauge glass model, we calculate the density of states, inverse participation ratios, and their spatial correlations. It turns out that their behavior is quite different from those expected within naive weak disorder approaches.

A Bipartite Interaction between Hsp70 and CHIP Regulates Ubiquitination of Chaperoned Client Proteins

DOE PAGES

Zhang, Huaqun; Amick, Joseph; Chakravarti, Ritu; ...

2015-02-12

The ubiquitin ligase CHIP plays an important role in cytosolic protein quality control by ubiquitinating proteins chaperoned by Hsp70/Hsc70 and Hsp90, thereby targeting such substrate proteins for degradation. We present a 2.91 Å resolution structure of the tetratricopeptide repeat (TPR) domain of CHIP in complex with the α-helical lid subdomain and unstructured tail of Hsc70. Surprisingly, the CHIP-TPR interacts with determinants within both the Hsc70-lid subdomain and the C-terminal PTIEEVD motif of the tail, exhibiting an atypical mode of interaction between chaperones and TPR domains. Here, we demonstrate that the interaction between CHIP and the Hsc70-lid subdomain is required formore » proper ubiquitination of Hsp70/Hsc70 or Hsp70/Hsc70-bound substrate proteins. Posttranslational modifications of the Hsc70 lid and tail disrupt key contacts with the CHIP-TPR and may regulate CHIP-mediated ubiquitination. Our study shows how CHIP docks onto Hsp70/Hsc70 and defines a bipartite mode of interaction between TPR domains and their binding partners.« less

Influence of intrinsic decoherence on tripartite entanglement and bipartite fidelity of polar molecules in pendular states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Jia-Xing; Hu, Yuan; Jin, Yu

An array of ultracold polar molecules trapped in an external electric field is regarded as a promising carrier of quantum information. Under the action of this field, molecules are compelled to undergo pendular oscillations by the Stark effect. Particular attention has been paid to the influence of intrinsic decoherence on the model of linear polar molecular pendular states, thereby we evaluate the tripartite entanglement with negativity, as well as fidelity of bipartite quantum systems for input and output signals using electric dipole moments of polar molecules as qubits. According to this study, we consider three typical initial states for bothmore » systems, respectively, and investigate the temporal evolution with variable values of the external field intensity, the intrinsic decoherence factor, and the dipole-dipole interaction. Thus, we demonstrate the sound selection of these three main parameters to obtain the best entanglement degree and fidelity.« less

Quantum discord with weak measurement operators of quasi-Werner states based on bipartite entangled coherent states

NASA Astrophysics Data System (ADS)

Castro, E.; Gómez, R.; Ladera, C. L.; Zambrano, A.

2013-11-01

Among many applications quantum weak measurements have been shown to be important in exploring fundamental physics issues, such as the experimental violation of the Heisenberg uncertainty relation and the Hardy paradox, and have also technological implications in quantum optics, quantum metrology and quantum communications, where the precision of the measurement is as important as the precision of quantum state preparation. The theory of weak measurement can be formulated using the pre-and post-selected quantum systems, as well as using the weak measurement operator formalism. In this work, we study the quantum discord (QD) of quasi-Werner mixed states based on bipartite entangled coherent states using the weak measurements operator, instead of the projective measurement operators. We then compare the quantum discord for both kinds of measurement operators, in terms of the entanglement quality, the latter being measured using the concept of concurrence. It's found greater quantum correlations using the weak measurement operators.

Bank-firm credit network in Japan: an analysis of a bipartite network.

PubMed

Marotta, Luca; Miccichè, Salvatore; Fujiwara, Yoshi; Iyetomi, Hiroshi; Aoyama, Hideaki; Gallegati, Mauro; Mantegna, Rosario N

2015-01-01

We investigate the networked nature of the Japanese credit market. Our investigation is performed with tools of network science. In our investigation we perform community detection with an algorithm which is identifying communities composed of both banks and firms. We show that the communities obtained by directly working on the bipartite network carry information about the networked nature of the Japanese credit market. Our analysis is performed for each calendar year during the time period from 1980 to 2011. To investigate the time evolution of the networked structure of the credit market we introduce a new statistical method to track the time evolution of detected communities. We then characterize the time evolution of communities by detecting for each time evolving set of communities the over-expression of attributes of firms and banks. Specifically, we consider as attributes the economic sector and the geographical location of firms and the type of banks. In our 32-year-long analysis we detect a persistence of the over-expression of attributes of communities of banks and firms together with a slow dynamic of changes from some specific attributes to new ones. Our empirical observations show that the credit market in Japan is a networked market where the type of banks, geographical location of firms and banks, and economic sector of the firm play a role in shaping the credit relationships between banks and firms.

Enabling Comprehension of Patient Subgroups and Characteristics in Large Bipartite Networks: Implications for Precision Medicine

PubMed Central

Bhavnani, Suresh K.; Chen, Tianlong; Ayyaswamy, Archana; Visweswaran, Shyam; Bellala, Gowtham; Rohit, Divekar; Kevin E., Bassler

2017-01-01

A primary goal of precision medicine is to identify patient subgroups based on their characteristics (e.g., comorbidities or genes) with the goal of designing more targeted interventions. While network visualization methods such as Fruchterman-Reingold have been used to successfully identify such patient subgroups in small to medium sized data sets, they often fail to reveal comprehensible visual patterns in large and dense networks despite having significant clustering. We therefore developed an algorithm called ExplodeLayout, which exploits the existence of significant clusters in bipartite networks to automatically “explode” a traditional network layout with the goal of separating overlapping clusters, while at the same time preserving key network topological properties that are critical for the comprehension of patient subgroups. We demonstrate the utility of ExplodeLayout by visualizing a large dataset extracted from Medicare consisting of readmitted hip-fracture patients and their comorbidities, demonstrate its statistically significant improvement over a traditional layout algorithm, and discuss how the resulting network visualization enabled clinicians to infer mechanisms precipitating hospital readmission in specific patient subgroups. PMID:28815099

Reaction Factoring and Bipartite Update Graphs Accelerate the Gillespie Algorithm for Large-Scale Biochemical Systems

PubMed Central

Indurkhya, Sagar; Beal, Jacob

2010-01-01

ODE simulations of chemical systems perform poorly when some of the species have extremely low concentrations. Stochastic simulation methods, which can handle this case, have been impractical for large systems due to computational complexity. We observe, however, that when modeling complex biological systems: (1) a small number of reactions tend to occur a disproportionately large percentage of the time, and (2) a small number of species tend to participate in a disproportionately large percentage of reactions. We exploit these properties in LOLCAT Method, a new implementation of the Gillespie Algorithm. First, factoring reaction propensities allows many propensities dependent on a single species to be updated in a single operation. Second, representing dependencies between reactions with a bipartite graph of reactions and species requires only storage for reactions, rather than the required for a graph that includes only reactions. Together, these improvements allow our implementation of LOLCAT Method to execute orders of magnitude faster than currently existing Gillespie Algorithm variants when simulating several yeast MAPK cascade models. PMID:20066048

Enhancing the absorption and energy transfer process via quantum entanglement

NASA Astrophysics Data System (ADS)

Zong, Xiao-Lan; Song, Wei; Zhou, Jian; Yang, Ming; Yu, Long-Bao; Cao, Zhuo-Liang

2018-07-01

The quantum network model is widely used to describe the dynamics of excitation energy transfer in photosynthesis complexes. Different from the previous schemes, we explore a specific network model, which includes both light-harvesting and energy transfer process. Here, we define a rescaled measure to manifest the energy transfer efficiency from external driving to the sink, and the external driving fields are used to simulate the energy absorption process. To study the role of initial state in the light-harvesting and energy transfer process, we assume the initial state of the donors to be two-qubit and three-qubit entangled states, respectively. In the two-qubit initial state case, we find that the initial entanglement between the donors can help to improve the absorption and energy transfer process for both the near-resonant and large-detuning cases. For the case of three-qubit initial state, we can see that the transfer efficiency will reach a larger value faster in the tripartite entanglement case compared to the bipartite entanglement case.

Driving performance changes of middle-aged experienced taxi drivers due to distraction tasks during unexpected situations.

PubMed

Kim, Hyung-Sik; Choi, Mi-Hyun; Choi, Jin-Seung; Kim, Hyun-Joo; Hong, Sang-Pyo; Jun, Jae-Hoon; Tack, Gye-Rae; Kim, Boseong; Min, Ung-Chan; Lim, Dae-Woon; Chung, Soon-Cheol

2013-10-01

This study investigated the effects of distraction taskssuch as sending a text message with a cellphone and searching navigation with car navigation system-on the driving performance of 29 highly experienced taxi drivers in their 50s. All participants were instructed to drive using a driving simulator for 2 min. while maintaining a constant distance from the vehicle in front and a constant speed. Participants drove without any distractions for the first minute. For an additional minute, they performed Driving Only or performed a task while driving (Driving + Sending Text Message or Driving + Searching Navigation). An unexpected situation, in which the participant had to stop abruptly due to a sudden stop of the preceding vehicle, occurred during this period. Driving performance during the unexpected situation was evaluated by car control variables, medial-lateral coefficient of variation and brake time, and by motion variables such as the jerk-cost function. Compared to Driving Only, jerk-cost function, medial-lateral coefficient of variation, and brake time increased during Driving + Sending Text Message or Driving + Searching Navigation.

Effects of Initial Correlation and Quantum Coherence on the Energy Transfer, Purity and Entanglement

NASA Astrophysics Data System (ADS)

Meng, Xiangjia; Chen, Longxi

2018-04-01

We investigate the influences of the initial correlation and quantum coherence on a bipartite dissipative system which is modeled by two two-level quantum emitters driven by an external laser field. It is shown that the initial correlation can enhance or suppress the dynamical evolution of the energy transfer quantified by the excited-state population and the information flow between the two emitters characterized by the purity. We also present the degree of the influence of the initial correlation that is determined by the quantum coherence induced by a relative phase. By introducing Bloch sphere, we illustrate the relation between the energy transfer and the purity. In addition, a scheme for generating maximally entangled steady state is proposed.

Energy conservation through utilization of mechanical energy storage

NASA Astrophysics Data System (ADS)

Eisenhaure, D. B.; Bliamptis, T. E.; Downer, J. R.; Heinemann, P. C.

Potential benefits regarding fuel savings, necessary technology, and evaluation criteria for the development of flywheel-hybrid vehicles are examined. A case study is quoted in which adoption of flywheel-hybrid vehicles in a taxi fleet would result in an increase of 10 mpg average to 32 mpg. Two proposed systems are described, one involving direct engine power to the flywheel and the second regenerating the flywheel from braking energy through a continuously variable transmission. Fuel consumption characteristics are considered the ultimate determinant in the choice of configuration, while material properties and housing shape determine the flywheel speed range. Vehicle losses are characterized and it is expected that a flywheel at 12,000 rpm will experience less than one hp average parasitic power loss. Flywheel storage is suitable for smaller engines because larger engines dominate the power train mass. Areas considered important for further investigation include reliability of an engine run near maximum torque, noise and vibration associated with flywheel operation, start up delays, compatibility of driver controls, integration of normal with regenerative braking systems, and, most importantly, the continuously variable transmission.

Measurement and simulation of the relatively competitive advantages and weaknesses between economies based on bipartite graph theory

PubMed Central

Guan, Jun; Xu, Xiaoyu; Wu, Shan

2018-01-01

The input-output table is very comprehensive and detailed in describing the national economic systems with abundant economic relationships, which contain supply and demand information among various industrial sectors. The complex network, a theory, and method for measuring the structure of a complex system can depict the structural characteristics of the internal structure of the researched object by measuring the structural indicators of the social and economic systems, revealing the complex relationships between the inner hierarchies and the external economic functions. In this paper, functions of industrial sectors on the global value chain are to be distinguished with bipartite graph theory, and inter-sector competitive relationships are to be extracted through resource allocation process. Furthermore, quantitative analysis indices will be proposed under the perspective of a complex network, which will be used to bring about simulations on the variation tendencies of economies’ status in different situations of commercial intercourses. Finally, a new econophysics analytical framework of international trade is to be established. PMID:29813083

Measurement and simulation of the relatively competitive advantages and weaknesses between economies based on bipartite graph theory.

PubMed

Guan, Jun; Xu, Xiaoyu; Wu, Shan; Xing, Lizhi

2018-01-01

The input-output table is very comprehensive and detailed in describing the national economic systems with abundant economic relationships, which contain supply and demand information among various industrial sectors. The complex network, a theory, and method for measuring the structure of a complex system can depict the structural characteristics of the internal structure of the researched object by measuring the structural indicators of the social and economic systems, revealing the complex relationships between the inner hierarchies and the external economic functions. In this paper, functions of industrial sectors on the global value chain are to be distinguished with bipartite graph theory, and inter-sector competitive relationships are to be extracted through resource allocation process. Furthermore, quantitative analysis indices will be proposed under the perspective of a complex network, which will be used to bring about simulations on the variation tendencies of economies' status in different situations of commercial intercourses. Finally, a new econophysics analytical framework of international trade is to be established.

The General Evolving Model for Energy Supply-Demand Network with Local-World

NASA Astrophysics Data System (ADS)

Sun, Mei; Han, Dun; Li, Dandan; Fang, Cuicui

2013-10-01

In this paper, two general bipartite network evolving models for energy supply-demand network with local-world are proposed. The node weight distribution, the "shifting coefficient" and the scaling exponent of two different kinds of nodes are presented by the mean-field theory. The numerical results of the node weight distribution and the edge weight distribution are also investigated. The production's shifted power law (SPL) distribution of coal enterprises and the installed capacity's distribution of power plants in the US are obtained from the empirical analysis. Numerical simulations and empirical results are given to verify the theoretical results.

Bank-Firm Credit Network in Japan: An Analysis of a Bipartite Network

PubMed Central

Marotta, Luca; Miccichè, Salvatore; Fujiwara, Yoshi; Iyetomi, Hiroshi; Aoyama, Hideaki; Gallegati, Mauro; Mantegna, Rosario N.

2015-01-01

We investigate the networked nature of the Japanese credit market. Our investigation is performed with tools of network science. In our investigation we perform community detection with an algorithm which is identifying communities composed of both banks and firms. We show that the communities obtained by directly working on the bipartite network carry information about the networked nature of the Japanese credit market. Our analysis is performed for each calendar year during the time period from 1980 to 2011. To investigate the time evolution of the networked structure of the credit market we introduce a new statistical method to track the time evolution of detected communities. We then characterize the time evolution of communities by detecting for each time evolving set of communities the over-expression of attributes of firms and banks. Specifically, we consider as attributes the economic sector and the geographical location of firms and the type of banks. In our 32-year-long analysis we detect a persistence of the over-expression of attributes of communities of banks and firms together with a slow dynamic of changes from some specific attributes to new ones. Our empirical observations show that the credit market in Japan is a networked market where the type of banks, geographical location of firms and banks, and economic sector of the firm play a role in shaping the credit relationships between banks and firms. PMID:25933413

A Bipartite Signal Regulates the Faithful Delivery of Apical Domain Marker Podocalyxin/Gp135

PubMed Central

Yu, Chun-Ying; Chen, Jen-Yau; Lin, Yu-Yu; Shen, Kuo-Fang; Lin, Wei-Ling; Chien, Chung-Liang; ter Beest, Martin B.A.

2007-01-01

Podocalyxin/Gp135 was recently demonstrated to participate in the formation of a preapical complex to set up initial polarity in MDCK cells, a function presumably depending on the apical targeting of Gp135. We show that correct apical sorting of Gp135 depends on a bipartite signal composed of an extracellular O-glycosylation–rich region and the intracellular PDZ domain–binding motif. The function of this PDZ-binding motif could be substituted with a fusion construct of Gp135 with Ezrin-binding phosphoprotein 50 (EBP50). In accordance with this observation, EBP50 binds to newly synthesized Gp135 at the Golgi apparatus and facilitates oligomerization and sorting of Gp135 into a clustering complex. A defective connection between Gp135 and EBP50 or EBP50 knockdown results in a delayed exit from the detergent-resistant microdomain, failure of oligomerization, and basolateral missorting of Gp135. Furthermore, the basolaterally missorted EBP50-binding defective mutant of Gp135 was rapidly retrieved via a PKC-dependent mechanism. According to these findings, we propose a model by which a highly negative charged transmembrane protein could be packed into an apical sorting platform with the aid of its cytoplasmic partner EBP50. PMID:17332505

Structure of multiphoton quantum optics. II. Bipartite systems, physical processes, and heterodyne squeezed states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dell'Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio

2004-03-01

Extending the scheme developed for a single mode of the electromagnetic field in the preceding paper [F. Dell'Anno, S. De Siena, and F. Illuminati, Phys. Rev. A 69, 033812 (2004)], we introduce two-mode nonlinear canonical transformations depending on two heterodyne mixing angles. They are defined in terms of Hermitian nonlinear functions that realize heterodyne superpositions of conjugate quadratures of bipartite systems. The canonical transformations diagonalize a class of Hamiltonians describing nondegenerate and degenerate multiphoton processes. We determine the coherent states associated with the canonical transformations, which generalize the nondegenerate two-photon squeezed states. Such heterodyne multiphoton squeezed states are defined asmore » the simultaneous eigenstates of the transformed, coupled annihilation operators. They are generated by nonlinear unitary evolutions acting on two-mode squeezed states. They are non-Gaussian, highly nonclassical, entangled states. For a quadratic nonlinearity the heterodyne multiphoton squeezed states define two-mode cubic phase states. The statistical properties of these states can be widely adjusted by tuning the heterodyne mixing angles, the phases of the nonlinear couplings, as well as the strength of the nonlinearity. For quadratic nonlinearity, we study the higher-order contributions to the susceptibility in nonlinear media and we suggest possible experimental realizations of multiphoton conversion processes generating the cubic-phase heterodyne squeezed states.« less

Structure of multiphoton quantum optics. II. Bipartite systems, physical processes, and heterodyne squeezed states

NASA Astrophysics Data System (ADS)

dell'Anno, Fabio; de Siena, Silvio; Illuminati, Fabrizio

2004-03-01

Extending the scheme developed for a single mode of the electromagnetic field in the preceding paper [

A matrix-algebraic formulation of distributed-memory maximal cardinality matching algorithms in bipartite graphs

DOE PAGES

Azad, Ariful; Buluç, Aydın

2016-05-16

We describe parallel algorithms for computing maximal cardinality matching in a bipartite graph on distributed-memory systems. Unlike traditional algorithms that match one vertex at a time, our algorithms process many unmatched vertices simultaneously using a matrix-algebraic formulation of maximal matching. This generic matrix-algebraic framework is used to develop three efficient maximal matching algorithms with minimal changes. The newly developed algorithms have two benefits over existing graph-based algorithms. First, unlike existing parallel algorithms, cardinality of matching obtained by the new algorithms stays constant with increasing processor counts, which is important for predictable and reproducible performance. Second, relying on bulk-synchronous matrix operations,more » these algorithms expose a higher degree of parallelism on distributed-memory platforms than existing graph-based algorithms. We report high-performance implementations of three maximal matching algorithms using hybrid OpenMP-MPI and evaluate the performance of these algorithm using more than 35 real and randomly generated graphs. On real instances, our algorithms achieve up to 200 × speedup on 2048 cores of a Cray XC30 supercomputer. Even higher speedups are obtained on larger synthetically generated graphs where our algorithms show good scaling on up to 16,384 cores.« less

Wnt-Mediated Repression via Bipartite DNA Recognition by TCF in the Drosophila Hematopoietic System

PubMed Central

Zhang, Chen U.; Blauwkamp, Timothy A.; Burby, Peter E.; Cadigan, Ken M.

2014-01-01

The Wnt/β-catenin signaling pathway plays many important roles in animal development, tissue homeostasis and human disease. Transcription factors of the TCF family mediate many Wnt transcriptional responses, promoting signal-dependent activation or repression of target gene expression. The mechanism of this specificity is poorly understood. Previously, we demonstrated that for activated targets in Drosophila, TCF/Pangolin (the fly TCF) recognizes regulatory DNA through two DNA binding domains, with the High Mobility Group (HMG) domain binding HMG sites and the adjacent C-clamp domain binding Helper sites. Here, we report that TCF/Pangolin utilizes a similar bipartite mechanism to recognize and regulate several Wnt-repressed targets, but through HMG and Helper sites whose sequences are distinct from those found in activated targets. The type of HMG and Helper sites is sufficient to direct activation or repression of Wnt regulated cis-regulatory modules, and protease digestion studies suggest that TCF/Pangolin adopts distinct conformations when bound to either HMG-Helper site pair. This repressive mechanism occurs in the fly lymph gland, the larval hematopoietic organ, where Wnt/β-catenin signaling controls prohemocytic differentiation. Our study provides a paradigm for direct repression of target gene expression by Wnt/β-catenin signaling and allosteric regulation of a transcription factor by DNA. PMID:25144371

NO and NO2 emission ratios measured from in-use commercial aircraft during taxi and takeoff.

PubMed

Herndon, Scott C; Shorter, Joanne H; Zahniser, Mark S; Nelson, David D; Jayne, John; Brown, Robert C; Miake-Lye, Richard C; Waitz, Ian; Silva, Phillip; Lanni, Thomas; Demerjian, Ken; Kolb, Charles E

2004-11-15

In August 2001, the Aerodyne Mobile Laboratory simultaneously measured NO, NO2, and CO2 within 350 m of a taxiway and 550 m of a runway at John F. Kennedy Airport. The meteorological conditions were such that taxi and takeoff plumes from individual aircraft were clearly resolved against background levels. NO and NO2 concentrations were measured with 1 s time resolution using a dual tunable infrared laser differential absorption spectroscopy instrument, utilizing an astigmatic multipass Herriott cell. The CO2 measurements were also obtained at 1 s time resolution using a commercial non-dispersive infrared absorption instrument. Plumes were measured from over 30 individual planes, ranging from turbo props to jumbo jets. NOx emission indices were determined by examining the correlation between NOx (NO + NO2) and CO2 during the plume measurements. Several aircraft tail numbers were unambiguously identified, allowing those specific airframe/engine combinations to be determined. The resulting NOx emission indices from positively identified in-service operating airplanes are compared with the published International Civil Aviation Organization engine certification test database collected on new engines in certification test cells.

Taxi driver training in Madagascar: the first step in developing a functioning prehospital emergency care system.

PubMed

Geduld, Heike; Wallis, Lee

2011-09-01

Prehospital care in developing countries is severely lacking. Few countries can afford the relatively expensive formalised Western model of a prehospital emergency medical system. The WHO has highlighted the development of layperson first responder programmes as the most basic step in the development of a functioning prehospital system. To describe the first training programme of its kind, run in Mahajanga, Madagascar. The faculty was invited by Mahajanga Medical School. Local input was taken into account in developing the curriculum. 26 taxi drivers were invited to attend in cooperation with the local municipality. The faculty consisted of five instructors from the Division of Emergency Medicine and EMSSA, plus local doctors from University Hospital Mahajanga. The 1-day course included workshops on prehospital scene management, bleeding and broken bones, immobilisation and patient movement, and labour and delivery. The workshops made use of commonly available items only including packets, string and towels; French and Malagasy translators were available throughout. Both faculty and candidates deemed the course a success and plans for formal evaluation of knowledge and skill retention are underway. Future plans are to continue the training using local instructors and in rural districts.

Computing Maximum Cardinality Matchings in Parallel on Bipartite Graphs via Tree-Grafting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azad, Ariful; Buluc, Aydn; Pothen, Alex

It is difficult to obtain high performance when computing matchings on parallel processors because matching algorithms explicitly or implicitly search for paths in the graph, and when these paths become long, there is little concurrency. In spite of this limitation, we present a new algorithm and its shared-memory parallelization that achieves good performance and scalability in computing maximum cardinality matchings in bipartite graphs. This algorithm searches for augmenting paths via specialized breadth-first searches (BFS) from multiple source vertices, hence creating more parallelism than single source algorithms. Algorithms that employ multiple-source searches cannot discard a search tree once no augmenting pathmore » is discovered from the tree, unlike algorithms that rely on single-source searches. We describe a novel tree-grafting method that eliminates most of the redundant edge traversals resulting from this property of multiple-source searches. We also employ the recent direction-optimizing BFS algorithm as a subroutine to discover augmenting paths faster. Our algorithm compares favorably with the current best algorithms in terms of the number of edges traversed, the average augmenting path length, and the number of iterations. Here, we provide a proof of correctness for our algorithm. Our NUMA-aware implementation is scalable to 80 threads of an Intel multiprocessor and to 240 threads on an Intel Knights Corner coprocessor. On average, our parallel algorithm runs an order of magnitude faster than the fastest algorithms available. The performance improvement is more significant on graphs with small matching number.« less

Computing Maximum Cardinality Matchings in Parallel on Bipartite Graphs via Tree-Grafting

DOE PAGES

Azad, Ariful; Buluc, Aydn; Pothen, Alex

2016-03-24

It is difficult to obtain high performance when computing matchings on parallel processors because matching algorithms explicitly or implicitly search for paths in the graph, and when these paths become long, there is little concurrency. In spite of this limitation, we present a new algorithm and its shared-memory parallelization that achieves good performance and scalability in computing maximum cardinality matchings in bipartite graphs. This algorithm searches for augmenting paths via specialized breadth-first searches (BFS) from multiple source vertices, hence creating more parallelism than single source algorithms. Algorithms that employ multiple-source searches cannot discard a search tree once no augmenting pathmore » is discovered from the tree, unlike algorithms that rely on single-source searches. We describe a novel tree-grafting method that eliminates most of the redundant edge traversals resulting from this property of multiple-source searches. We also employ the recent direction-optimizing BFS algorithm as a subroutine to discover augmenting paths faster. Our algorithm compares favorably with the current best algorithms in terms of the number of edges traversed, the average augmenting path length, and the number of iterations. Here, we provide a proof of correctness for our algorithm. Our NUMA-aware implementation is scalable to 80 threads of an Intel multiprocessor and to 240 threads on an Intel Knights Corner coprocessor. On average, our parallel algorithm runs an order of magnitude faster than the fastest algorithms available. The performance improvement is more significant on graphs with small matching number.« less

Fault tolerance in protein interaction networks: stable bipartite subgraphs and redundant pathways.

PubMed

Brady, Arthur; Maxwell, Kyle; Daniels, Noah; Cowen, Lenore J

2009-01-01

As increasing amounts of high-throughput data for the yeast interactome become available, more system-wide properties are uncovered. One interesting question concerns the fault tolerance of protein interaction networks: whether there exist alternative pathways that can perform some required function if a gene essential to the main mechanism is defective, absent or suppressed. A signature pattern for redundant pathways is the BPM (between-pathway model) motif, introduced by Kelley and Ideker. Past methods proposed to search the yeast interactome for BPM motifs have had several important limitations. First, they have been driven heuristically by local greedy searches, which can lead to the inclusion of extra genes that may not belong in the motif; second, they have been validated solely by functional coherence of the putative pathways using GO enrichment, making it difficult to evaluate putative BPMs in the absence of already known biological annotation. We introduce stable bipartite subgraphs, and show they form a clean and efficient way of generating meaningful BPMs which naturally discard extra genes included by local greedy methods. We show by GO enrichment measures that our BPM set outperforms previous work, covering more known complexes and functional pathways. Perhaps most importantly, since our BPMs are initially generated by examining the genetic-interaction network only, the location of edges in the protein-protein physical interaction network can then be used to statistically validate each candidate BPM, even with sparse GO annotation (or none at all). We uncover some interesting biological examples of previously unknown putative redundant pathways in such areas as vesicle-mediated transport and DNA repair.

Fault Tolerance in Protein Interaction Networks: Stable Bipartite Subgraphs and Redundant Pathways

PubMed Central

Brady, Arthur; Maxwell, Kyle; Daniels, Noah; Cowen, Lenore J.

2009-01-01

As increasing amounts of high-throughput data for the yeast interactome become available, more system-wide properties are uncovered. One interesting question concerns the fault tolerance of protein interaction networks: whether there exist alternative pathways that can perform some required function if a gene essential to the main mechanism is defective, absent or suppressed. A signature pattern for redundant pathways is the BPM (between-pathway model) motif, introduced by Kelley and Ideker. Past methods proposed to search the yeast interactome for BPM motifs have had several important limitations. First, they have been driven heuristically by local greedy searches, which can lead to the inclusion of extra genes that may not belong in the motif; second, they have been validated solely by functional coherence of the putative pathways using GO enrichment, making it difficult to evaluate putative BPMs in the absence of already known biological annotation. We introduce stable bipartite subgraphs, and show they form a clean and efficient way of generating meaningful BPMs which naturally discard extra genes included by local greedy methods. We show by GO enrichment measures that our BPM set outperforms previous work, covering more known complexes and functional pathways. Perhaps most importantly, since our BPMs are initially generated by examining the genetic-interaction network only, the location of edges in the protein-protein physical interaction network can then be used to statistically validate each candidate BPM, even with sparse GO annotation (or none at all). We uncover some interesting biological examples of previously unknown putative redundant pathways in such areas as vesicle-mediated transport and DNA repair. PMID:19399174

Factors associated with HIV testing among male motorbike taxi drivers in urban Vietnam.

PubMed

Huy, Nguyen Van; Khuyen, Le Thi; Ha, Pham Nguyen

2015-01-01

Using the Attitude-Skills-Knowledge (ASK) model, this study examined the prevalence of, and factors associated with, human immunodeficiency virus (HIV) testing among male motorbike taxi drivers (MMTDs). In a cross-sectional design, using quantitative approaches, 291 MMTDs were recruited from 135 sites across 13 districts in Hanoi, Vietnam, for a face-to-face interview. Applying the ASK model modified as a central theory, logistic regression was used to identify determinants of HIV testing. Although many MMTDs engaged in multiple risk behaviours for HIV, only 20.6% had been tested for HIV during the past 12 months. The tested model included one factor of the ASK model, HIV prevention knowledge (adjusted odds ratio [AOR] = 4.76; 95% confidence interval [CI] = 2.12-10.7) and five additional factors: being married (AOR = 3.13; 95% CI = 1.25-4.78), preferring sex with men or with both men and women (AOR = 8.72; 95% CI = 1.48-51.5), having lower number of lifetime sex partners (AOR = 0.66; 95% CI = 0.49-0.88), higher number of past year sex partners (AOR = 2.97: 95% CI = 1.21-7.31) and discussing condom use when having sex with partners (AOR = 0.08; 95% CI = 0.01-7.31). This modified ASK model provided better fit than the ASK model, as it explained more variance in HIV testing (47 vs. 29.8%). Recognising factors associated with HIV testing among MMTDs enables us to create suitable public health intervention strategies.

Bipartite life cycle of coral reef fishes promotes increasing shape disparity of the head skeleton during ontogeny: an example from damselfishes (Pomacentridae)

PubMed Central

2011-01-01

Background Quantitative studies of the variation of disparity during ontogeny exhibited by the radiation of coral reef fishes are lacking. Such studies dealing with the variation of disparity, i.e. the diversity of organic form, over ontogeny could be a first step in detecting evolutionary mechanisms in these fishes. The damselfishes (Pomacentridae) have a bipartite life-cycle, as do the majority of demersal coral reef fishes. During their pelagic dispersion phase, all larvae feed on planktonic prey. On the other hand, juveniles and adults associated with the coral reef environment show a higher diversity of diets. Using geometric morphometrics, we study the ontogenetic dynamic of shape disparity of different head skeletal units (neurocranium, suspensorium and opercle, mandible and premaxilla) in this fish family. We expected that larvae of different species might be relatively similar in shapes. Alternatively, specialization may become notable even in the juvenile and adult phase. Results The disparity levels increase significantly throughout ontogeny for each skeletal unit. At settlement, all larval shapes are already species-specific. Damselfishes show high levels of ontogenetic allometry during their post-settlement growth. The divergence of allometric patterns largely explains the changes in patterns and levels of shape disparity over ontogeny. The rate of shape change and the length of ontogenetic trajectories seem to be less variable among species. We also show that the high levels of shape disparity at the adult stage are correlated to a higher level of ecological and functional diversity in this stage. Conclusion Diversification throughout ontogeny of damselfishes results from the interaction among several developmental novelties enhancing disparity. The bipartite life-cycle of damselfishes exemplifies a case where the variation of environmental factors, i.e. the transition from the more homogeneous oceanic environment to the coral reef offering a wide

B800-B850 coherence correlates with energy transfer rates in the LH2 complex of photosynthetic purple bacteria.

PubMed

Smyth, Cathal; Oblinsky, Daniel G; Scholes, Gregory D

2015-12-14

Until recently, no analytical measure of many-body delocalization in open systems had been developed, yet such a measure enables characterization of how molecular excitons delocalize in photosynthetic light-harvesting complexes, and in turn helps us understand quantum coherent aspects of electronic energy transfer. In this paper we apply these measures to a model peripheral light-harvesting complex, LH2 from Rhodopseudomonas acidophila. We find how many chromophores collectively contribute to the "delocalization length" of an excitation within LH2 and how the coherent delocalization is distributed spatially. We also investigate to what extent this delocalization length is effective, by examining the impact of bipartite and multipartite entanglement in inter-ring energy transfer in LH2.

Gaussian maximally multipartite-entangled states

NASA Astrophysics Data System (ADS)

Facchi, Paolo; Florio, Giuseppe; Lupo, Cosmo; Mancini, Stefano; Pascazio, Saverio

2009-12-01

We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7 .

Bipartite Structure of the 5s Ribosomal Gene Family in a Drosophila Melanogaster Strain, and Its Evolutionary Implications

PubMed Central

Samson, M. L.; Wegnez, M.

1988-01-01

Knowledge of multigenic family organization should provide insight into their mode of evolution. Accordingly, we characterized the 5S ribosomal gene family in the Drosophila melanogaster strain ry(506). The 5S genes in this strain display a striking HindIII restriction difference compared to the ``standard'' D. melanogaster 5S genes. The sequence of three ry(506) 5S genes was determined. We show that the HindIII restriction site heterogeneity within the ry(506) 5S family most probably results from the same point mutation, suggesting that a single 5S variant was propagated into the 5S cluster of this strain. Furthermore, we demonstrate that the structural organization of the 5S genes in ry(506) is a bipartite structure, i.e., that about 40% of the 5S genes constitute a HindIII(+)/HindIII(-) mixed cluster, while those remaining constitute an homogeneous HindIII(-) cluster. The events which might lead to such an heterogeneous pattern are discussed from an evolutionary point of view. PMID:2835290

Myocardial infarction among male bus, taxi, and lorry drivers in middle Sweden.

PubMed Central

Gustavsson, P; Alfredsson, L; Brunnberg, H; Hammar, N; Jakobsson, R; Reuterwall, C; Ostlin, P

1996-01-01

OBJECTIVES: The aim of the present case-referent study was to investigate the incidence of myocardial infarction among male professional drivers, taking the type of vehicles and area of residence into account. METHODS: The study base comprised all men aged 30-74 in five counties in middle Sweden during 1976-81 or 1976-84. Incident cases of the first episode of myocardial infarction were identified from registers of hospital admissions and causes of deaths. Referents were selected randomly from the study base. Information about occupation was obtained from the national censuses in 1970 and 1975. The possible impact from tobacco smoking and overweight were evaluated by simulations in combination with indirect data on these factors. RESULTS: The incidence of myocardial infarction was increased among bus drivers in Stockholm (relative risk (RR) = 1.53, 95% confidence interval (95% CI) 1.15-2.05), and among taxi drivers both in Stockholm (RR 1.65, 95% CI 1.30-2.11) and in the surrounding rural counties (RR 1.82, 95% CI 1.17-2.82). A smaller increase was found among long distance lorry drivers, whereas the relative risk among short distance lorry drivers was close to unity. Indirect comparisons make it unlikely that the excess among bus drivers in Stockholm could be explained by uncontrolled confounding from tobacco smoking or overweight. A very high proportion (more than 80%) of urban bus drivers in Sweden report a combination of high psychological demands and low control at work. CONCLUSIONS: Different types of drivers are at different risk of myocardial infarction. Bus drivers in urban areas seem to be at an increased risk, which is unlikely to be explained by uncontrolled confounding from tobacco smoking or overweight. Psychosocial work conditions may play a part in the increased incidence of myocardial infarction among urban bus drivers and should be investigated further. PMID:8664960

X-36 Tailless Fighter Agility Research Aircraft on lakebed during high-speed taxi tests

NASA Technical Reports Server (NTRS)

1996-01-01

The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. More taxi and radio frequency tests were slated before it's first flight would be made. This took place on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems

Real-world fuel efficiency and exhaust emissions of light-duty diesel vehicles and their correlation with road conditions.

PubMed

Hu, Jingnan; Wu, Ye; Wang, Zhishi; Li, Zhenhua; Zhou, Yu; Wang, Haitao; Bao, Xiaofeng; Hao, Jiming

2012-01-01

The real-world fuel efficiency and exhaust emission profiles of CO, HC and NOx for light-duty diesel vehicles were investigated. Using a portable emissions measurement system, 16 diesel taxies were tested on different roads in Macao and the data were normalized with the vehicle specific power bin method. The 11 Toyota Corolla diesel taxies have very good fuel economy of (5.9 +/- 0.6) L/100 km, while other five diesel taxies showed relatively high values at (8.5 +/- 1.7) L/100 km due to the variation in transmission systems and emission control strategies. Compared to similar Corolla gasoline models, the diesel cars confirmed an advantage of ca. 20% higher fuel efficiency. HC and CO emissions of all the 16 taxies are quite low, with the average at (0.05 +/- 0.02) g/km and (0.38 +/- 0.15) g/km, respectively. The average NOx emission factor of the 11 Corolla taxies is (0.56 +/- 0.17) g/km, about three times higher than their gasoline counterparts. Two of the three Hyundai Sonata taxies, configured with exhaust gas recirculation (EGR) + diesel oxidation catalyst (DOC) emission control strategies, indicated significantly higher NO2 emissions and NO2/NOx ratios than other diesel taxies and consequently trigger a concern of possibly adverse impacts on ozone pollution in urban areas with this technology combination. A clear and similar pattern for fuel consumption and for each of the three gaseous pollutant emissions with various road conditions was identified. To save energy and mitigate CO2 emissions as well as other gaseous pollutant emissions in urban area, traffic planning also needs improvement.

Molecular characterization and origin of novel bipartite cold-regulated ice recrystallization inhibition proteins from cereals.

PubMed

Tremblay, Karine; Ouellet, François; Fournier, Julie; Danyluk, Jean; Sarhan, Fathey

2005-06-01

To understand the molecular basis of freezing tolerance in plants, several low temperature-responsive genes have been identified from wheat. Among these are two genes named TaIRI-1 and TaIRI-2 (Triticum aestivum ice recrystallization inhibition) that are up-regulated during cold acclimation in freezing-tolerant species. Phytohormones involved in pathogen defense pathways (jasmonic acid and ethylene) induce the expression of one of the two genes. The encoded proteins are novel in that they have a bipartite structure that has never been reported for antifreeze proteins. Their N-terminal part shows similarity with the leucine-rich repeat-containing regions present in the receptor domain of receptor-like protein kinases, and their C-terminus is homologous to the ice-binding domain of some antifreeze proteins. The recombinant TaIRI-1 protein inhibits the growth of ice crystals, confirming its function as an ice recrystallization inhibition protein. The TaIRI genes were found only in the species belonging to the Pooideae subfamily of cereals. Comparative genomic analysis suggested that molecular evolutionary events took place in the genome of freezing-tolerant cereals to give rise to these genes with putative novel functions. These apparent adaptive DNA rearrangement events could be part of the molecular mechanisms that ensure the survival of hardy cereals in the harsh freezing environments.

Mextli proteins use both canonical bipartite and novel tripartite binding modes to form eIF4E complexes that display differential sensitivity to 4E-BP regulation

PubMed Central

Peter, Daniel; Weber, Ramona; Köne, Carolin; Chung, Min-Yi; Ebertsch, Linda; Truffault, Vincent; Weichenrieder, Oliver; Igreja, Cátia; Izaurralde, Elisa

2015-01-01

The eIF4E-binding proteins (4E-BPs) are a diverse class of translation regulators that share a canonical eIF4E-binding motif (4E-BM) with eIF4G. Consequently, they compete with eIF4G for binding to eIF4E, thereby inhibiting translation initiation. Mextli (Mxt) is an unusual 4E-BP that promotes translation by also interacting with eIF3. Here we present the crystal structures of the eIF4E-binding regions of the Drosophila melanogaster (Dm) and Caenorhabditis elegans (Ce) Mxt proteins in complex with eIF4E in the cap-bound and cap-free states. The structures reveal unexpected evolutionary plasticity in the eIF4E-binding mode, with a classical bipartite interface for Ce Mxt and a novel tripartite interface for Dm Mxt. Both interfaces comprise a canonical helix and a noncanonical helix that engage the dorsal and lateral surfaces of eIF4E, respectively. Remarkably, Dm Mxt contains a C-terminal auxiliary helix that lies anti-parallel to the canonical helix on the eIF4E dorsal surface. In contrast to the eIF4G and Ce Mxt complexes, the Dm eIF4E–Mxt complexes are resistant to competition by bipartite 4E-BPs, suggesting that Dm Mxt can bind eIF4E when eIF4G binding is inhibited. Our results uncovered unexpected diversity in the binding modes of 4E-BPs, resulting in eIF4E complexes that display differential sensitivity to 4E-BP regulation. PMID:26294658

Political Obstacles to Regionalization of the SUS: perceptions of Municipal Health Secretaries with seat in the Bipartite Interagency Commissions.

PubMed

Moreira, Marcelo Rasga; Ribeiro, José Mendes; Ouverney, Assis Mafort

2017-04-01

This paper aims to identify and analyze the political obstacles to the implementation of Organizational Contract of Public Action (COAP) based on the perceptions of municipal health secretaries of Bipartite Interagency Commissions (CIB). For this purpose, we interviewed 195 secretaries (92% of the total) from October 2015 to August 2016. Based on the approach of policy analysis, the main hurdles identified were, in short, a traditional obstacle (lack of resources), one that has been gaining strength in recent years (judicialization of politics) and another, perhaps unheard of: the party-political system and the State Executive Branch are the great absentees in the coalitions in support of SUS regionalization policies. We can conclude that such obstacles indicate an extremely negative setting for the implementation of the COAP and other SUS regionalization policies. Thus, it is incumbent upon those involved to reflect, negotiate and build consensus on improving the health of the population and overcome such obstacles if, of course, they embrace the authors' concept that regionalization is fundamental for the SUS.

Transport emissions: All hail robocabs

NASA Astrophysics Data System (ADS)

Brown, Austin

2015-09-01

Connected and automated vehicles enable new business models, such as self-driving taxis, that could transform transportation. These models have the potential to reduce energy consumption and greenhouse-gas emissions, but only if they are developed with energy use in mind.

Complete nucleotide sequences of a new bipartite begomovirus from Malvastrum sp. plants with bright yellow mosaic symptoms in South Texas.

PubMed

Alabi, Olufemi J; Villegas, Cecilia; Gregg, Lori; Murray, K Daniel

2016-06-01

Two isolates of a novel bipartite begomovirus, tentatively named malvastrum bright yellow mosaic virus (MaBYMV), were molecularly characterized from naturally infected plants of the genus Malvastrum showing bright yellow mosaic disease symptoms in South Texas. Six complete DNA-A and five DNA-B genome sequences of MaBYMV obtained from the isolates ranged in length from 2,608 to 2,609 nucleotides (nt) and 2,578 to 2,605 nt, respectively. Both genome segments shared a 178- to 180-nt common region. In pairwise comparisons, the complete DNA-A and DNA-B sequences of MaBYMV were most similar (87-88 % and 79-81 % identity, respectively) and phylogenetically related to the corresponding sequences of sida mosaic Sinaloa virus-[MX-Gua-06]. Further analysis revealed that MaBYMV is a putative recombinant virus, thus supporting the notion that malvaceous hosts may be influencing the evolution of several begomoviruses. The design of new diagnostic primers enabled the detection of MaBYMV in cohorts of Bemisia tabaci collected from symptomatic Malvastrum sp. plants, thus implicating whiteflies as potential vectors of the virus.

Enhancement of human DNA polymerase η activity and fidelity is dependent upon a bipartite interaction with the Werner syndrome protein.

PubMed

Maddukuri, Leena; Ketkar, Amit; Eddy, Sarah; Zafar, Maroof K; Griffin, Wezley C; Eoff, Robert L

2012-12-07

We have investigated the interaction between human DNA polymerase η (hpol η) and the Werner syndrome protein (WRN). Functional assays revealed that the WRN exonuclease and RecQ C-terminal (RQC) domains are necessary for full stimulation of hpol η-catalyzed formation of correct base pairs. We find that WRN does not stimulate hpol η-catalyzed formation of mispairs. Moreover, the exonuclease activity of WRN prevents stable mispair formation by hpol η. These results are consistent with a proofreading activity for WRN during single-nucleotide additions. ATP hydrolysis by WRN appears to attenuate stimulation of hpol η. Pre-steady-state kinetic results show that k(pol) is increased 4-fold by WRN. Finally, pulldown assays reveal a bipartite physical interaction between hpol η and WRN that is mediated by the exonuclease and RQC domains. Taken together, these results are consistent with alteration of the rate-limiting step in polymerase catalysis by direct protein-protein interactions between WRN and hpol η. In summary, WRN improves the efficiency and fidelity of hpol η to promote more effective replication of DNA.

Isolation, Purification, and Identification of Taxol and Related Taxanes from Taxol-Producing Fungus Aspergillus niger subsp. taxi.

PubMed

Li, Dan; Fu, Dongwei; Zhang, Yue; Ma, Xueling; Gao, Liguo; Wang, Xioahua; Zhou, Dongpo; Zhao, Kai

2017-08-28

The content of taxol in the bark of yews is very low, and this is not affordable from the environmental point of view. Thus, it is a necessity to look for alternative sources of taxol production to solve its supply. Currently, a large portion of the taxol in the market comes from chemical semi-synthesis, but the semi-synthetic precursors such as baccatin III and 10-deacetyl-baccatin III are extracted from needles and twigs of yew trees. Taxol-producing fungi as a renewable resource is a very promising way to increase the scale of taxol production. Our group has obtained a taxol-producing endophytic fungus, Aspergillus niger subsp. taxi HD86-9, to examine if A. niger can produce the taxanes. Six compounds from the fermentation broth of strain HD86-9 were isolated and identified by 1 H NMR, 13 C NMR, and ESI-MS. The results showed that the six compounds included four taxane diterpenoids (taxol, cephalomannine, baccatin III, and 10-deacetyl-baccatin III) and two non-taxane compounds (β-sitosterol and flavonoid isovitexin). The study verified that the taxanes can be produced by the A. niger , which is very important to taxol production via chemical semi-synthesis. Additionally, the finding is potentially very significant to solve the taxol semi-synthetic precursors extracted from needles and twigs of yew trees, and the precursor production can be easily increased through the culture condition optimization, genetic breeding, and metabolic engineering of the A. niger .

Modeling silicon diode energy response factors for use in therapeutic photon beams.

PubMed

Eklund, Karin; Ahnesjö, Anders

2009-10-21

Silicon diodes have good spatial resolution, which makes them advantageous over ionization chambers for dosimetry in fields with high dose gradients. However, silicon diodes overrespond to low-energy photons, that are more abundant in scatter which increase with large fields and larger depths. We present a cavity-theory-based model for a general response function for silicon detectors at arbitrary positions within photon fields. The model uses photon and electron spectra calculated from fluence pencil kernels. The incident photons are treated according to their energy through a bipartition of the primary beam photon spectrum into low- and high-energy components. Primary electrons from the high-energy component are treated according to Spencer-Attix cavity theory. Low-energy primary photons together with all scattered photons are treated according to large cavity theory supplemented with an energy-dependent factor K(E) to compensate for energy variations in the electron equilibrium. The depth variation of the response for an unshielded silicon detector has been calculated for 5 x 5 cm(2), 10 x 10 cm(2) and 20 x 20 cm(2) fields in 6 and 15 MV beams and compared with measurements showing that our model calculates response factors with deviations less than 0.6%. An alternative method is also proposed, where we show that one can use a correlation with the scatter factor to determine the detector response of silicon diodes with an error of less than 3% in 6 MV and 15 MV photon beams.

POM-ZP3, a bipartite transcript derived from human ZP3 and a POM121 homologue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kipersztok, S.; Osawa, G.A.; Liang, L.F.

1995-01-20

Human POM-ZP3 is a novel bipartite RNA transcript that is derived from a gene homologous to rat POM121 (a nuclear pore membrane protein) and ZP3 (a sperm receptor ligand in the zona pellucida). The 5{prime} region is 77% identical to the 5{prime} end of the coding region of rat POM121 and appears to represent a partial duplication of a gene encoding a human homologue of this rodent gene. The 3{prime} end of the POM-ZP3 transcript is 99% identical to ZP3 and appears to have arisen from a duplication of the last four exons (exons 5-8) of ZP3. Using Northern blotsmore » and RT-PCR, POM-ZP3 transcripts were detected in human ovaries, testes, spleen, thymus, lymphocytes, prostate, and intestines. The longest open reading frame encodes a conceptual protein of 210 amino acids, the first 76 of which are 83% identical to residues 241-315 of rat POM121. The next 125 amino acids are 98% identical to residues 239-363 of the 424-amino-acid human ZP3 protein. By fluorescence in situ hybridization, genomic fragments of ZP3 and a human homologue of POM121 were localized to chromosome 7q11.23. Taken together, these data suggest that partial duplications of human ZP3 and a POM121-like gene have resulted in a fusion transcript, POM-ZP3, that is expressed in multiple human tissues. 24 refs., 5 figs.« less

Step On It! Impact of a Workplace New York City Taxi Driver Health Intervention to Increase Necessary Health Care Access

PubMed Central

Gany, Francesca; Bari, Sehrish; Gill, Pavan; Loeb, Rebecca

2015-01-01

Objectives. We describe the impact of the Step On It! intervention to link taxi drivers, particularly South Asians, to health insurance enrollment and navigate them into care when necessary. Methods. Step On It! was a worksite initiative held for 5 consecutive days from September 28 to October 2, 2011, at John F. Kennedy International Airport in New York City. Data collected included sociodemographics, employment, health care access and use, height, weight, blood pressure, and random plasma glucose. Participants were given their results, counseled by a medical professional, and invited to participate in free workshops provided by partner organizations. Results. Of the 466 drivers participated, 52% were uninsured, and 49% did not have a primary care provider. Of 384 drivers who had blood pressure, glucose, or both measured, 242 (63%) required urgent or regular follow-up. Of the 77 (32%) requiring urgent follow-up, 50 (65%) sought medical care at least once, of whom 13 (26%) received a new diagnosis. Of the 165 (68%) requiring regular follow-up, 68 (41%) sought medical care at least once, of whom 5 (7%) received a new diagnosis. Conclusions. This study provides encouraging results about the potential impact of an easy-to-deliver, easily scalable workplace intervention with a large, vulnerable population. PMID:25211738

SR-71 - Taxi on Ramp with Engines

NASA Technical Reports Server (NTRS)

1995-01-01

This photo shows a head-on shot of NASA's SR-71A aircraft taxiing on the ramp at NASA's Dryden Flight Research Center, Edwards, California, heat waves from its engines blurring the hangars in the background. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena

Investigating Einstein-Podolsky-Rosen steering of continuous-variable bipartite states by non-Gaussian pseudospin measurements

NASA Astrophysics Data System (ADS)

Xiang, Yu; Xu, Buqing; Mišta, Ladislav; Tufarelli, Tommaso; He, Qiongyi; Adesso, Gerardo

2017-10-01

Einstein-Podolsky-Rosen (EPR) steering is an asymmetric form of correlations which is intermediate between quantum entanglement and Bell nonlocality, and can be exploited as a resource for quantum communication with one untrusted party. In particular, steering of continuous-variable Gaussian states has been extensively studied theoretically and experimentally, as a fundamental manifestation of the EPR paradox. While most of these studies focused on quadrature measurements for steering detection, two recent works revealed that there exist Gaussian states which are only steerable by suitable non-Gaussian measurements. In this paper we perform a systematic investigation of EPR steering of bipartite Gaussian states by pseudospin measurements, complementing and extending previous findings. We first derive the density-matrix elements of two-mode squeezed thermal Gaussian states in the Fock basis, which may be of independent interest. We then use such a representation to investigate steering of these states as detected by a simple nonlinear criterion, based on second moments of the correlation matrix constructed from pseudospin operators. This analysis reveals previously unexplored regimes where non-Gaussian measurements are shown to be more effective than Gaussian ones to witness steering of Gaussian states in the presence of local noise. We further consider an alternative set of pseudospin observables, whose expectation value can be expressed more compactly in terms of Wigner functions for all two-mode Gaussian states. However, according to the adopted criterion, these observables are found to be always less sensitive than conventional Gaussian observables for steering detection. Finally, we investigate continuous-variable Werner states, which are non-Gaussian mixtures of Gaussian states, and find that pseudospin measurements are always more effective than Gaussian ones to reveal their steerability. Our results provide useful insights on the role of non

14 CFR 205.5 - Minimum coverage.

Code of Federal Regulations, 2011 CFR

2011-01-01

... commuter air carriers but excluding U.S. air taxi operators and Canadian charter air taxi operators, shall...,000 times 75 percent of the number of passenger seats installed in the aircraft. (c) U.S. air taxi... each occurrence for loss of or damage to property. (2) U.S. air taxi operators carrying passengers in...

14 CFR 205.5 - Minimum coverage.

Code of Federal Regulations, 2010 CFR

2010-01-01

... commuter air carriers but excluding U.S. air taxi operators and Canadian charter air taxi operators, shall...,000 times 75 percent of the number of passenger seats installed in the aircraft. (c) U.S. air taxi... each occurrence for loss of or damage to property. (2) U.S. air taxi operators carrying passengers in...

Three state-of-the-art individual electric and hybrid vehicle test reports, volume 2

NASA Technical Reports Server (NTRS)

1978-01-01

Procedures used in determining the energy efficiency and economy of a gasoline-electric hybrid taxi, an electric passenger car, and an electric van are described. Tabular and graphic data show results of driving cycle and constant speed tests, energy distribution to various components, efficiency of the components, and, for the hybrid vehicle, the emissions.

Lowering transit crime may save energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Shifting travelers from less-energy-efficient automobiles to more-energy-efficient transit vehicles is an essential energy conservation measure. During peak travel periods the average auto carries 1.4 persons and consumes 16 times more fuel per passenger mile than an urban bus carrying an average of 75 passengers. Today's travelers are using transit for less than 3 percent of their urban trips. Travelers reject transit because its costs--in terms of time, money, and quality of service--are higher than those for the auto. One element of the higher cost of using transit is the increased exposure to crime which occurs when a traveler shifts frommore » his private car to mass transit. The increased exposure is the result of the additional time transit travelers spend getting to and waiting at transit stops, as well as the additional time spent riding, and the lack of privacy while on transit. Furthermore, transit travelers have no control over their route, which may go through high-crime areas. In contrast, traveling by auto not only eliminates the time getting to and waiting at transit stops, but it also provides a secure compartment which can be locked. Traveling companions can be chosen to limit exposure to crime. In addition, auto travel provides the opportunity to select the safest and shortest route. Between the two extremes of high exposure to crime presented by public transit and low exposure to crime offered by private autos lies para-transit, such as taxis, carpools, and jitneys (small buses that carry passengers over a regular route according to a flexible schedule). (MCW)« less

Role of quantum coherence in the thermodynamics of energy transfer

NASA Astrophysics Data System (ADS)

Henao, Ivan; Serra, Roberto M.

2018-06-01

Recent research on the thermodynamic arrow of time, at the microscopic scale, has questioned the universality of its direction. Theoretical studies showed that quantum correlations can be used to revert the natural heat flow (from the hot body to the cold one), posing an apparent challenge to the second law of thermodynamics. Such an "anomalous" heat current was observed in a recent experiment (K. Micadei et al., arXiv:1711.03323), by employing two spin systems initially quantum correlated. Nevertheless, the precise relationship between this intriguing phenomenon and the initial conditions that allow it is not fully evident. Here, we address energy transfer in a wider perspective, identifying a nonclassical contribution that applies to the reversion of the heat flow as well as to more general forms of energy exchange. We derive three theorems that describe the energy transfer between two microscopic systems, for arbitrary initial bipartite states. Using these theorems, we obtain an analytical bound showing that certain type of quantum coherence can optimize such a process, outperforming incoherent states. This genuine quantum advantage is corroborated through a characterization of the energy transfer between two qubits. For this system, it is shown that a large enough amount of coherence is necessary and sufficient to revert the thermodynamic arrow of time. As a second crucial consequence of the presented theorems, we introduce a class of nonequilibrium states that only allow unidirectional energy flow. In this way, we broaden the set where the standard Clausius statement of the second law applies.

Aircraft Energy Conservation during Airport Ground Operations

DTIC Science & Technology

1982-03-01

minimized. The model can be run in a non -optimizing mode to simulate movements along pre-assigned taxi paths. 8-6 The model is also designed ...5.5 5.6 5.7 Engine Designation by Airline and Aircraft Type IAD 2-6 Engine Designation by Airline and Aircraft Type DCA 2-7 Fuel Flow Rates...B.2 CY 1979 Aircraft Operations at IAD and DCA Airports . . 3-5 B.3 1979 Scheduled and Non -Scheduled Departures from IAD by Aircraft Type and

14 CFR 298.24 - Cancellation of the registration.

Code of Federal Regulations, 2010 CFR

2010-01-01

... PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Registration for Exemption by Air Taxi Operators § 298.24 Cancellation of the registration. The registration of an air taxi...

14 CFR 298.24 - Cancellation of the registration.

Code of Federal Regulations, 2011 CFR

2011-01-01

... PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Registration for Exemption by Air Taxi Operators § 298.24 Cancellation of the registration. The registration of an air taxi...

Efficiency of VIGS and gene expression in a novel bipartite potexvirus vector delivery system as a function of strength of TGB1 silencing suppression.

PubMed

Lim, Hyoun-Sub; Vaira, Anna Maria; Domier, Leslie L; Lee, Sung Chul; Kim, Hong Gi; Hammond, John

2010-06-20

We have developed plant virus-based vectors for virus-induced gene silencing (VIGS) and protein expression, based on Alternanthera mosaic virus (AltMV), for infection of a wide range of host plants including Nicotiana benthamiana and Arabidopsis thaliana by either mechanical inoculation of in vitro transcripts or via agroinfiltration. In vivo transcripts produced by co-agroinfiltration of bacteriophage T7 RNA polymerase resulted in T7-driven AltMV infection from a binary vector in the absence of the Cauliflower mosaic virus 35S promoter. An artificial bipartite viral vector delivery system was created by separating the AltMV RNA-dependent RNA polymerase and Triple Gene Block (TGB)123-Coat protein (CP) coding regions into two constructs each bearing the AltMV 5' and 3' non-coding regions, which recombined in planta to generate a full-length AltMV genome. Substitution of TGB1 L(88)P, and equivalent changes in other potexvirus TGB1 proteins, affected RNA silencing suppression efficacy and suitability of the vectors from protein expression to VIGS. Published by Elsevier Inc.

A Visit to Taxicab Geometry

ERIC Educational Resources Information Center

Hanson, J. R.

2012-01-01

The taxi metric is introduced, compared to the Euclidean metric, and used to define the taxi circle. For all pairs of points "A" and "B" the set of points equally distant under the taxi metric to "A" and to "B" is determined. For any triangle these sets are used to either find the centre of a taxi circle that can circumscribe the triangle or to…

Developmental anomaly of ossification type patella partita.

PubMed

Oohashi, Yoshikazu

2015-04-01

Bipartite patella has been recognized as an incidental radiographic finding. However, symptomatic bipartite patella is occasionally diagnosed in adolescents and young athletes. The incidence of bipartite patella has been reported at 0.2-1.7, and 1-2 % of these cases are symptomatic. The purpose of this review article was to discuss current concepts relevant to developmental anomaly of ossification type patella partita. A PubMed database search using the key words "bipartite patella" was performed. Clinical papers reporting the bipartite patella were included. Four German-language studies were also included, three for incidence of bipartite patella and one for classification. A new classification of developmental anomaly of ossification type patella partita based on location and number of fragment was recently proposed. It is simple and useful and applicable to all types of bipartite or tripartite patella. Several imaging studies have reportedly been used to evaluate symptomatic bipartite patella. MRI is currently the most appropriate method used to assess patients with bipartite patella. Although surgical procedures have been developed that reduce excessive traction force by the vastus lateralis muscle on the bipartite fragment, there is not sufficient evidence to support their use for routine treatment of painful bipartite patella. In most symptomatic cases, movement at the interface between the bipartite fragment and the body of the patella presumably causes the pain. Therefore, the existence of apparent motion at the interface should be confirmed by specific imaging studies before surgery. Magnetic resonance imaging findings may provide such evidence by demonstrating a fluid bright signal across the segmentation, typical of pseudoarthrosis. V.

Invariant measures on multimode quantum Gaussian states

NASA Astrophysics Data System (ADS)

Lupo, C.; Mancini, S.; De Pasquale, A.; Facchi, P.; Florio, G.; Pascazio, S.

2012-12-01

We derive the invariant measure on the manifold of multimode quantum Gaussian states, induced by the Haar measure on the group of Gaussian unitary transformations. To this end, by introducing a bipartition of the system in two disjoint subsystems, we use a parameterization highlighting the role of nonlocal degrees of freedom—the symplectic eigenvalues—which characterize quantum entanglement across the given bipartition. A finite measure is then obtained by imposing a physically motivated energy constraint. By averaging over the local degrees of freedom we finally derive the invariant distribution of the symplectic eigenvalues in some cases of particular interest for applications in quantum optics and quantum information.

Engineering Safety- and Security-Related Requirements for Software-Intensive Systems

DTIC Science & Technology

2007-05-31

University Very Large New Zoo Parking Lots Zoo Back Lots Restaurants and Shops Tropical Rainforest African SavannaChildren’s Petting Area Monkeys Great Apes...decide to ride to the Great Apes and Monkeys taxi station near the central shops and restaurants area. Mr. Smith then swipes his zoo taxi travel card...taxi station on their right, circles around the central area, and soon pulls off the Zoo Loop Line to enter the inner Great Apes and Monkeys taxi

Multipartite entanglement and frustration

NASA Astrophysics Data System (ADS)

Facchi, P.; Florio, G.; Marzolino, U.; Parisi, G.; Pascazio, S.

2010-02-01

Some features of the global entanglement of a composed quantum system can be quantified in terms of the purity of a balanced bipartition, made up of half of its subsystems. For the given bipartition, purity can always be minimized by taking a suitable (pure) state. When many bipartitions are considered, the requirement that purity be minimal for all bipartitions can engender conflicts and frustration will arise. This unearths an interesting link between frustration and multipartite entanglement, defined as the average purity over all (balanced) bipartitions.

14 CFR 294.32 - Security arrangements for operating Public Charters.

Code of Federal Regulations, 2010 CFR

2010-01-01

... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS General Rules for Registrants § 294.32 Security arrangements for operating Public Charters. When a Canadian charter air taxi... taxi operator shall meet the bonding or escrow requirements applicable to foreign air carriers as set...

14 CFR 294.32 - Security arrangements for operating Public Charters.

Code of Federal Regulations, 2011 CFR

2011-01-01

... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS General Rules for Registrants § 294.32 Security arrangements for operating Public Charters. When a Canadian charter air taxi... taxi operator shall meet the bonding or escrow requirements applicable to foreign air carriers as set...

14 CFR 294.20 - Applying for registration.

Code of Federal Regulations, 2011 CFR

2011-01-01

... PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS Registration for Exemption § 294.20 Applying for registration. To apply for registration under this part, a Canadian charter air taxi operator... shall be certified by a responsible officer of the applicant Canadian charter air taxi operator...

14 CFR 294.20 - Applying for registration.

Code of Federal Regulations, 2010 CFR

2010-01-01

... PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS Registration for Exemption § 294.20 Applying for registration. To apply for registration under this part, a Canadian charter air taxi operator... shall be certified by a responsible officer of the applicant Canadian charter air taxi operator...

Maximally multipartite entangled states

NASA Astrophysics Data System (ADS)

Facchi, Paolo; Florio, Giuseppe; Parisi, Giorgio; Pascazio, Saverio

2008-06-01

We introduce the notion of maximally multipartite entangled states of n qubits as a generalization of the bipartite case. These pure states have a bipartite entanglement that does not depend on the bipartition and is maximal for all possible bipartitions. They are solutions of a minimization problem. Examples for small n are investigated, both analytically and numerically.

14 CFR 298.30 - Public disclosure of policy on consumer protection.

Code of Federal Regulations, 2011 CFR

2011-01-01

... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS... protection. (a) Every air taxi and commuter air carrier shall cause to be displayed continuously in a..., containing a statement setting forth the air taxi and commuter air carrier's policy on baggage liability and...

14 CFR 298.38 - Financial security arrangements for operating Public Charters.

Code of Federal Regulations, 2010 CFR

2010-01-01

... OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER... security arrangements for operating Public Charters. When an air taxi operator or commuter air carrier performs a Public Charter under part 380 of this chapter, either: (a) The air taxi operator or commuter air...

14 CFR 298.23 - Notifications to the Department of change in operations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Registration for Exemption by Air Taxi Operators § 298.23 Notifications to the Department of change in operations. (a) If any of the information contained on its registration changes, an air taxi...

14 CFR 294.1 - Applicability and purpose.

Code of Federal Regulations, 2010 CFR

2010-01-01

... PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS General § 294.1 Applicability and... taxi operators,” and establishes registration procedures for these carriers operating or seeking to... air taxi operators from certain provisions of the Subtitle VII of Title 49 of the United States Code...

14 CFR 298.38 - Financial security arrangements for operating Public Charters.

Code of Federal Regulations, 2011 CFR

2011-01-01

... OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER... security arrangements for operating Public Charters. When an air taxi operator or commuter air carrier performs a Public Charter under part 380 of this chapter, either: (a) The air taxi operator or commuter air...

14 CFR 294.30 - Scope of service and equipment authorized.

Code of Federal Regulations, 2010 CFR

2010-01-01

... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS General Rules for... air service, and the exemption provided by this part to Canadian charter air taxi operators that... charter air taxi operator shall not use large aircraft for charter air service until it has been granted a...

14 CFR 294.1 - Applicability and purpose.

Code of Federal Regulations, 2011 CFR

2011-01-01

... PROCEEDINGS) ECONOMIC REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS General § 294.1 Applicability and... taxi operators,” and establishes registration procedures for these carriers operating or seeking to... air taxi operators from certain provisions of the Subtitle VII of Title 49 of the United States Code...

14 CFR 298.23 - Notifications to the Department of change in operations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Registration for Exemption by Air Taxi Operators § 298.23 Notifications to the Department of change in operations. (a) If any of the information contained on its registration changes, an air taxi...

76 FR 72239 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-22

... Air Taxi and Commuter Air Carrier Operations AGENCY: Federal Aviation Administration (FAA), DOT... certificate of public convenience and necessity from the DOT, with the exception of air taxi and commuter air...: OMB Control Number: 2120-0633. Title: Exemptions for Air Taxi and Commuter Air Carrier Operations...

THE PROFITS AND PERILS OF PUBLICITY: ALLGEMEINE LITERATUR- ZEITUNG, THE THURN UND TAXIS POST, AND THE PERIODICAL TRADE AT THE END OF THE EIGHTEENTH CENTURY.

PubMed

Broman, Thomas

2015-09-20

Recent historiography on the growth of periodical publishing has emphasized newspapers and journals as constituents of an emergent communications system in early modern Europe. This system comprised the newspapers, journals and other publications that contributed its content, and also the postal systems that were the principal method of distributing that content. This article describes how the growth of this system in central Europe was supported in large measure by financial incentives that it offered to both constituents. First, in contrast with postal systems in France and the UK, the Thurn und Taxis Reichspost inserted itself as a middleman in the sale of periodicals, which gave the Reichspost an incentive to promote the trade. Second, the financial conditions for periodical publication made their costs depend more heavily on costs that were scalable to circulation than is true today, which resulted in the viability of publications with a lower circulation. The same cost structure also made it possible for certain prominent periodicals of the era to earn considerable profits for their publishers, as illustrated in this article by Allgemeine Literatur-Zeitung, which was published in Jena from 1785.

The profits and perils of publicity: Allgemeine Literatur-Zeitung, the Thurn und Taxis Post, and the periodical trade at the end of the eighteenth century

PubMed Central

Broman, Thomas

2015-01-01

Recent historiography on the growth of periodical publishing has emphasized newspapers and journals as constituents of an emergent communications system in early modern Europe. This system comprised the newspapers, journals and other publications that contributed its content, and also the postal systems that were the principal method of distributing that content. This article describes how the growth of this system in central Europe was supported in large measure by financial incentives that it offered to both constituents. First, in contrast with postal systems in France and the UK, the Thurn und Taxis Reichspost inserted itself as a middleman in the sale of periodicals, which gave the Reichspost an incentive to promote the trade. Second, the financial conditions for periodical publication made their costs depend more heavily on costs that were scalable to circulation than is true today, which resulted in the viability of publications with a lower circulation. The same cost structure also made it possible for certain prominent periodicals of the era to earn considerable profits for their publishers, as illustrated in this article by Allgemeine Literatur-Zeitung, which was published in Jena from 1785. PMID:26495577

The yeast Ty3 retrotransposon contains a 5'-3' bipartite primer-binding site and encodes nucleocapsid protein NCp9 functionally homologous to HIV-1 NCp7.

PubMed Central

Gabus, C; Ficheux, D; Rau, M; Keith, G; Sandmeyer, S; Darlix, J L

1998-01-01

Retroviruses, including HIV-1 and the distantly related yeast retroelement Ty3, all encode a nucleoprotein required for virion structure and replication. During an in vitro comparison of HIV-1 and Ty3 nucleoprotein function in RNA dimerization and cDNA synthesis, we discovered a bipartite primer-binding site (PBS) for Ty3 composed of sequences located at opposite ends of the genome. Ty3 cDNA synthesis requires the 3' PBS for primer tRNAiMet annealing to the genomic RNA, and the 5' PBS, in cis or in trans, as the reverse transcription start site. Ty3 RNA alone is unable to dimerize, but formation of dimeric tRNAiMet bound to the PBS was found to direct dimerization of Ty3 RNA-tRNAiMet. Interestingly, HIV-1 nucleocapsid protein NCp7 and Ty3 NCp9 were interchangeable using HIV-1 and Ty3 RNA template-primer systems. Our findings impact on the understanding of non-canonical reverse transcription as well as on the use of Ty3 systems to screen for anti-NCp7 drugs. PMID:9707446

The yeast Ty3 retrotransposon contains a 5'-3' bipartite primer-binding site and encodes nucleocapsid protein NCp9 functionally homologous to HIV-1 NCp7.

PubMed

Gabus, C; Ficheux, D; Rau, M; Keith, G; Sandmeyer, S; Darlix, J L

1998-08-17

Retroviruses, including HIV-1 and the distantly related yeast retroelement Ty3, all encode a nucleoprotein required for virion structure and replication. During an in vitro comparison of HIV-1 and Ty3 nucleoprotein function in RNA dimerization and cDNA synthesis, we discovered a bipartite primer-binding site (PBS) for Ty3 composed of sequences located at opposite ends of the genome. Ty3 cDNA synthesis requires the 3' PBS for primer tRNAiMet annealing to the genomic RNA, and the 5' PBS, in cis or in trans, as the reverse transcription start site. Ty3 RNA alone is unable to dimerize, but formation of dimeric tRNAiMet bound to the PBS was found to direct dimerization of Ty3 RNA-tRNAiMet. Interestingly, HIV-1 nucleocapsid protein NCp7 and Ty3 NCp9 were interchangeable using HIV-1 and Ty3 RNA template-primer systems. Our findings impact on the understanding of non-canonical reverse transcription as well as on the use of Ty3 systems to screen for anti-NCp7 drugs.

14 CFR 298.11 - Exemption authority.

Code of Federal Regulations, 2011 CFR

2011-01-01

... REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Exemptions § 298.11 Exemption authority. Air taxi operators and commuter air carriers are hereby relieved from the following provisions of... imposed herein, and to the extent necessary to permit them to conduct air taxi or commuter air carrier...

14 CFR 298.11 - Exemption authority.

Code of Federal Regulations, 2010 CFR

2010-01-01

... REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Exemptions § 298.11 Exemption authority. Air taxi operators and commuter air carriers are hereby relieved from the following provisions of... imposed herein, and to the extent necessary to permit them to conduct air taxi or commuter air carrier...

76 FR 17332 - Special Conditions: Embraer S.A.; Model EMB 500; Single-Place Side-Facing Seat Dynamic Test...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-29

... locked open during taxi, takeoff and landing. The adjacent forward wall/bulkhead interior structure will... inches of energy absorbing protective padding (foam or equivalent), such as Ensolite. 3. Thoracic Trauma... occupied, the lavatory door must be latched open for takeoff and landing and must remain latched under the...

Plant responses to tomato chlorotic mottle virus: Proteomic view of the resistance mechanisms to a bipartite begomovirus in tomato.

PubMed

Carmo, Lílian S T; Murad, André M; Resende, Renato O; Boiteux, Leonardo S; Ribeiro, Simone G; Jorrín-Novo, Jesús V; Mehta, Angela

2017-01-16

Tomato chlorotic mottle virus (ToCMoV) is a widespread bipartite Begomovirus species found in tomato fields in Brazil. In this study, plant responses and putative mechanisms associated with the 'Tyking'-derived recessive resistance to ToCMoV were investigated. Changes in the protein profile in the inoculated plants of two near isogenic tomato lines resistant ('LAM 157') and susceptible ('Santa Clara') to ToCMoV were analyzed. Seedlings were biolistically inoculated with an infectious ToCMoV clone. Leaves from infected plants (confirmed by PCR) were sampled at 15days after inoculation. Proteins were extracted using phenol and analyzed by shotgun MS (2D-nanoUPLC/HDMS E ). Out of the 534 identified proteins, 82 presented statistically significant differences in abundance, including 35 unique proteins displayed in the resistant tomato inoculated with ToCMoV. Proteins associated to chromatin structure, cytoskeleton structure, cuticle biosynthesis, and ubiquitin pathway were identified and their putative roles during virus infection process were discussed. The protein profile analysis allowed for the development of a hypothetical model showing how the resistant host cell responds to ToCMoV infection. The data obtained provide a better understanding of resistant mechanisms used by the host plant to contain viral infection and could be the basis for further investigation in other plant-begomovirus pathosystems. In this study we propose a model of resistance to begomovirus in tomato and highlight host proteins, which could be targets for future investigations in plant-begomovirus pathosystems. Copyright © 2016 Elsevier B.V. All rights reserved.

Cost-effectiveness analysis of CNG urban taxi operations.

DOT National Transportation Integrated Search

1993-10-01

Increased emphasis on energy efficiency and air quality has resulted in a number of state and federal initiatives : examining the use of alternative fuels for motor vehicles. Texas' program for alternate fuels includes compressed : natural gas (CNG)....

14 CFR 205.4 - Filing of evidence of insurance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... commuter air carriers and air taxi operators, and OST Form 6411 for foreign air carriers, including Canadian air taxi operators. The Department may return the certificate or self-insurance plan to the... Headquarters, AAL-230, 222 West 7th Avenue, Box 14, Anchorage, Alaska 99513. For Canadian air taxis, the forms...

14 CFR 205.4 - Filing of evidence of insurance.

Code of Federal Regulations, 2011 CFR

2011-01-01

... commuter air carriers and air taxi operators, and OST Form 6411 for foreign air carriers, including Canadian air taxi operators. The Department may return the certificate or self-insurance plan to the... Headquarters, AAL-230, 222 West 7th Avenue, Box 14, Anchorage, Alaska 99513. For Canadian air taxis, the forms...

14 CFR 294.31 - Use of business name.

Code of Federal Regulations, 2011 CFR

2011-01-01

... REGULATIONS CANADIAN CHARTER AIR TAXI OPERATORS General Rules for Registrants § 294.31 Use of business name. (a) A Canadian charter air taxi operator, in holding out charter air service to the public and... this part. The Department may require a Canadian charter air taxi operator to change such names where...

Anaerobic electron acceptor chemotaxis in Shewanella putrefaciens

NASA Technical Reports Server (NTRS)

Nealson, K. H.; Moser, D. P.; Saffarini, D. A.

1995-01-01

Shewanella putrefaciens MR-1 can grow either aerobically or anaerobically at the expense of many different electron acceptors and is often found in abundance at redox interfaces in nature. Such redox interfaces are often characterized by very strong gradients of electron acceptors resulting from rapid microbial metabolism. The coincidence of S. putrefaciens abundance with environmental gradients prompted an examination of the ability of MR-1 to sense and respond to electron acceptor gradients in the laboratory. In these experiments, taxis to the majority of the electron acceptors that S. putrefaciens utilizes for anaerobic growth was seen. All anaerobic electron acceptor taxis was eliminated by the presence of oxygen, nitrate, nitrite, elemental sulfur, or dimethyl sulfoxide, even though taxis to the latter was very weak and nitrate and nitrite respiration was normal in the presence of dimethyl sulfoxide. Studies with respiratory mutants of MR-1 revealed that several electron acceptors that could not be used for anaerobic growth nevertheless elicited normal anaerobic taxis. Mutant M56, which was unable to respire nitrite, showed normal taxis to nitrite, as well as the inhibition of taxis to other electron acceptors by nitrite. These results indicate that electron acceptor taxis in S. putrefaciens does not conform to the paradigm established for Escherichia coli and several other bacteria. Carbon chemo-taxis was also unusual in this organism: of all carbon compounds tested, the only positive response observed was to formate under anaerobic conditions.

Health risk equations and risk assessment of airborne benzene homologues exposure to drivers and passengers in taxi cabins.

PubMed

Chen, Xiaokai; Feng, Lili; Luo, Huilong; Cheng, Heming

2016-03-01

Interior air environment and health problems of vehicles have attracted increasing attention, and benzene homologues (BHs) including benzene, toluene, ethylbenzene, xylenes, and styrene are primary hazardous gases in vehicular cabins. The BHs impact on the health of passengers and drivers in 38 taxis is assessed, and health risk equations of in-car BHs to different drivers and passengers are induced. The health risk of in-car BHs for male drivers is the highest among all different receptors and is 1.04, 6.67, and 6.94 times more than ones for female drivers, male passengers, and female passengers, respectively. In-car BHs could not lead to the non-cancer health risk to all passengers and drivers as for the maximal value of non-cancer indices is 0.41 and is less than the unacceptable value (1.00) of non-cancer health risk from USEPA. However, in-car BHs lead to cancer health risk to drivers as for the average value of cancer indices is 1.21E-04 which is 1.21 times more than the unacceptable value (1.00E-04) of cancer health risk from USEPA. Finally, for in-car airborne benzene concentration (X, μg/m(3)) to male drivers, female drivers, male passengers, and female passengers, the cancer health risk equations are Y = 1.48E-06X, Y = 1.42E-06X, Y = 2.22E-07X, and Y = 2.13E-07X, respectively, and the non-cancer health risk equations are Y = 1.70E-03X, Y = 1.63E-03X, Y = 2.55E-04X, and Y = 2.45E-04X, respectively.

MIT - Massachusetts Institute of Technology

Science.gov Websites

energy cancer diversity global industry public service Solve The MIT Campaign for a Better World give to produce electricity Drug-carrying nanoparticles could help fight brain cancer Drug-carrying nanoparticles could help fight brain cancer New dispatching approach optimizes a city's taxi fleet New dispatching

14 CFR 298.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS General § 298.2 Definitions. As used in this part: Air taxi operator means an air carrier as established by § 298.3(a). Air transportation..., 39 U.S.C. 5402, authorizes the carriage of mail by air taxi operators and commuter air carriers in...

Quantifying the benefits of vehicle pooling with shareability networks

PubMed Central

Santi, Paolo; Resta, Giovanni; Szell, Michael; Sobolevsky, Stanislav; Strogatz, Steven H.; Ratti, Carlo

2014-01-01

Taxi services are a vital part of urban transportation, and a considerable contributor to traffic congestion and air pollution causing substantial adverse effects on human health. Sharing taxi trips is a possible way of reducing the negative impact of taxi services on cities, but this comes at the expense of passenger discomfort quantifiable in terms of a longer travel time. Due to computational challenges, taxi sharing has traditionally been approached on small scales, such as within airport perimeters, or with dynamical ad hoc heuristics. However, a mathematical framework for the systematic understanding of the tradeoff between collective benefits of sharing and individual passenger discomfort is lacking. Here we introduce the notion of shareability network, which allows us to model the collective benefits of sharing as a function of passenger inconvenience, and to efficiently compute optimal sharing strategies on massive datasets. We apply this framework to a dataset of millions of taxi trips taken in New York City, showing that with increasing but still relatively low passenger discomfort, cumulative trip length can be cut by 40% or more. This benefit comes with reductions in service cost, emissions, and with split fares, hinting toward a wide passenger acceptance of such a shared service. Simulation of a realistic online system demonstrates the feasibility of a shareable taxi service in New York City. Shareability as a function of trip density saturates fast, suggesting effectiveness of the taxi sharing system also in cities with much sparser taxi fleets or when willingness to share is low. PMID:25197046

Quantifying the benefits of vehicle pooling with shareability networks.

PubMed

Santi, Paolo; Resta, Giovanni; Szell, Michael; Sobolevsky, Stanislav; Strogatz, Steven H; Ratti, Carlo

2014-09-16

Taxi services are a vital part of urban transportation, and a considerable contributor to traffic congestion and air pollution causing substantial adverse effects on human health. Sharing taxi trips is a possible way of reducing the negative impact of taxi services on cities, but this comes at the expense of passenger discomfort quantifiable in terms of a longer travel time. Due to computational challenges, taxi sharing has traditionally been approached on small scales, such as within airport perimeters, or with dynamical ad hoc heuristics. However, a mathematical framework for the systematic understanding of the tradeoff between collective benefits of sharing and individual passenger discomfort is lacking. Here we introduce the notion of shareability network, which allows us to model the collective benefits of sharing as a function of passenger inconvenience, and to efficiently compute optimal sharing strategies on massive datasets. We apply this framework to a dataset of millions of taxi trips taken in New York City, showing that with increasing but still relatively low passenger discomfort, cumulative trip length can be cut by 40% or more. This benefit comes with reductions in service cost, emissions, and with split fares, hinting toward a wide passenger acceptance of such a shared service. Simulation of a realistic online system demonstrates the feasibility of a shareable taxi service in New York City. Shareability as a function of trip density saturates fast, suggesting effectiveness of the taxi sharing system also in cities with much sparser taxi fleets or when willingness to share is low.

Development of neuronal and sensorimotor systems in the absence of gravity: Neurobiological research on four soyuz taxi flights to the international space station

NASA Astrophysics Data System (ADS)

Horn, Eberhard R.; Dournon, Christian; Frippiat, Jean-Pol; Marco, Roberto; Böser, Sybille; Kirschnick, Uta

2007-09-01

Neurobiological experiments on 4 animal species (Xenopus laevis, Pleurodeles waltl, Drosophila melanogaster, Acheta domesticus) were performed to study effects of microgravity on development and aging of neuronal, sensory and motor systems. Animal models were selected according to their suitability to answer questions concerning μg-effects on neuroanatomy, neuronal activity, and behaviour. The studies were performed on the Soyuz Taxi flights Andromède, Cervantes, Eneide and LDM-TMA8/TMA7. Observations from these flights include: (1) In tadpoles and cricket larvae, morphological features of sensory cells and neurons are rarely affected by microgravity. (2) In crickets, in-flight fertilization was successful; after landing, flight larvae hatched earlier than ground reared siblings. (3) In crickets, proliferation of peptidergic neurons and their projection patterns within the nervous system were not affected by microgravity. (4) During aging, the impact of microgravity on peptidergic neurons of male Drosophila was limited to the size of cell body. (5) In Xenopus, neurophysiological features of the spinal motor system during fictive swimming were partially modified. (6) In Xenopus tadpoles, the vestibuloocular reflex was affected in an age-related manner. Modifications were also related to the occurrence of a tail lordosis induced by microgravity. It is concluded that adaptation to microgravity during development and aging is mainly based on physiological mechanisms within the central nervous system while structural modifications of the sensory and neuronal system contribute less.

Bipartite Network Analysis of the Archaeal Virosphere: Evolutionary Connections between Viruses and Capsidless Mobile Elements.

PubMed

Iranzo, Jaime; Koonin, Eugene V; Prangishvili, David; Krupovic, Mart

2016-12-15

Archaea and particularly hyperthermophilic crenarchaea are hosts to many unusual viruses with diverse virion shapes and distinct gene compositions. As is typical of viruses in general, there are no universal genes in the archaeal virosphere. Therefore, to obtain a comprehensive picture of the evolutionary relationships between viruses, network analysis methods are more productive than traditional phylogenetic approaches. Here we present a comprehensive comparative analysis of genomes and proteomes from all currently known taxonomically classified and unclassified, cultivated and uncultivated archaeal viruses. We constructed a bipartite network of archaeal viruses that includes two classes of nodes, the genomes and gene families that connect them. Dissection of this network using formal community detection methods reveals strong modularity, with 10 distinct modules and 3 putative supermodules. However, compared to similar previously analyzed networks of eukaryotic and bacterial viruses, the archaeal virus network is sparsely connected. With the exception of the tailed viruses related to bacteriophages of the order Caudovirales and the families Turriviridae and Sphaerolipoviridae that are linked to a distinct supermodule of eukaryotic and bacterial viruses, there are few connector genes shared by different archaeal virus modules. In contrast, most of these modules include, in addition to viruses, capsidless mobile elements, emphasizing tight evolutionary connections between the two types of entities in archaea. The relative contributions of distinct evolutionary origins, in particular from nonviral elements, and insufficient sampling to the sparsity of the archaeal virus network remain to be determined by further exploration of the archaeal virosphere. Viruses infecting archaea are among the most mysterious denizens of the virosphere. Many of these viruses display no genetic or even morphological relationship to viruses of bacteria and eukaryotes, raising questions

Bipartite Network Analysis of the Archaeal Virosphere: Evolutionary Connections between Viruses and Capsidless Mobile Elements

PubMed Central

Prangishvili, David

2016-01-01

ABSTRACT Archaea and particularly hyperthermophilic crenarchaea are hosts to many unusual viruses with diverse virion shapes and distinct gene compositions. As is typical of viruses in general, there are no universal genes in the archaeal virosphere. Therefore, to obtain a comprehensive picture of the evolutionary relationships between viruses, network analysis methods are more productive than traditional phylogenetic approaches. Here we present a comprehensive comparative analysis of genomes and proteomes from all currently known taxonomically classified and unclassified, cultivated and uncultivated archaeal viruses. We constructed a bipartite network of archaeal viruses that includes two classes of nodes, the genomes and gene families that connect them. Dissection of this network using formal community detection methods reveals strong modularity, with 10 distinct modules and 3 putative supermodules. However, compared to similar previously analyzed networks of eukaryotic and bacterial viruses, the archaeal virus network is sparsely connected. With the exception of the tailed viruses related to bacteriophages of the order Caudovirales and the families Turriviridae and Sphaerolipoviridae that are linked to a distinct supermodule of eukaryotic and bacterial viruses, there are few connector genes shared by different archaeal virus modules. In contrast, most of these modules include, in addition to viruses, capsidless mobile elements, emphasizing tight evolutionary connections between the two types of entities in archaea. The relative contributions of distinct evolutionary origins, in particular from nonviral elements, and insufficient sampling to the sparsity of the archaeal virus network remain to be determined by further exploration of the archaeal virosphere. IMPORTANCE Viruses infecting archaea are among the most mysterious denizens of the virosphere. Many of these viruses display no genetic or even morphological relationship to viruses of bacteria and eukaryotes